WHEREAS
That on 17 August 2010, in compliance with article 46, section I, of the Federal Act on Metrology and Standardisation, the Ministry of Labour and Social Welfare submitted to the National Consultative Committee for Standardisation on Occupational Safety and Health the Preliminary Draft Amendment to this Official Mexican Standard, and that the aforementioned Committee considered it correct and agreed that it be published as a Draft in the Official Gazette of the Federation; That to comply with articles 69-E and 69-H of the Federal Act on Administrative Procedure, the corresponding Preliminary Draft was submitted for the consideration of the Federal Commission for Regulatory Improvement, which issued a favourable opinion in relation thereto; That on 19 November 2010, in compliance with the Agreement establishing the organisation and Operating Rules of the National Consultative Committee for Standardisation on Occupational Safety and Health, and with article 47, section I, of the Federal Act on Metrology and Standardisation, the Draft Official Mexican Standard NOM-031-STPS-2010, Construction - Occupational safety and health conditions, was published in the Official Gazette of the Federation, so that, within the 60 calendar days following that publication, interested parties could submit their comments to the Committee; That having received comments from six proponents, the aforementioned Committee proceeded to study them and resolved on them in due course, this authority publishing the corresponding responses in the Official Gazette of the Federation of 25 March 2011, in compliance with article 47, section III, of the Federal Act on Metrology and Standardisation; That, as a result of the incorporation of the comments submitted on the Draft Official Mexican Standard NOM-031-STPS-2010, Construction - Occupational safety and health conditions, and of the final review of the draft itself, various modifications were made for the purpose of providing clarity, consistency and legal certainty as regards the provisions applicable in workplaces, and Whereas, in view of the foregoing considerations and given that the National Consultative Committee for Standardisation on Occupational Safety and Health granted its corresponding approval, the following is hereby issued: OFFICIAL MEXICAN STANDARD NOM-031-STPS-2011, CONSTRUCTION - OCCUPATIONAL SAFETY AND HEALTH CONDITIONS
CONTENTS
TRANSITIONAL PROVISIONS
Reference Guide I Signage on Construction Sites
1. Purpose
To establish the occupational safety and health conditions on construction sites, to prevent the occupational risks to which the workers who work there are exposed.
2. Scope
This Official Mexican Standard applies to all construction sites carried out within the national territory, in any of their various activities or phases. Maintenance activities on buildings or installations that do not require a construction licence or notification to the competent authority are excepted from this Official Mexican Standard.
3. References
For the correct interpretation of this Standard, the following current Official Mexican Standards, or those replacing them, shall be consulted:
3.1 NOM-002-STPS-2010, Safety conditions - Fire prevention and protection in workplaces.
3.2 NOM-004-STPS-1999, Protection systems and safety devices on machinery and equipment used in workplaces.
3.3 NOM-006-STPS-2000, Handling and storage of materials - Safety conditions and procedures.
3.4 NOM-009-STPS-2011, Safety conditions for work at height.
3.5 NOM-017-STPS-2008, Personal protective equipment - Selection, use and management in workplaces.
3.6 NOM-018-STPS-2000, System for the identification and communication of hazards and risks from hazardous chemical substances in workplaces.
3.7 NOM-019-STPS-2011, Constitution, composition, organisation and functioning of the safety and hygiene committees.
3.8 NOM-020-STPS-2002, Pressure vessels and boilers - Operation - Safety conditions.
3.9 NOM-021-STPS-1993, Concerning the requirements and characteristics of the reports on occupational risks that occur, for compiling statistics.
3.10 NOM-026-STPS-2008, Safety and hygiene colours and signs, and identification of hazards from fluids conveyed in pipework.
3.11 NOM-027-STPS-2008, Welding and cutting activities - Safety and health conditions.
3.12 NOM-029-STPS-2005, Maintenance of electrical installations in workplaces - Safety conditions.
3.13 NOM-030-STPS-2009, Preventive occupational safety and health services - Functions and activities.
4. Definitions
For the purposes of this Standard, the following definitions are laid down:
4.1 Analysis of potential risks: The document containing the characteristics of the construction site and the risks associated with each of the activities and phases carried out on it, as well as the preventive measures for each risk identified.
4.2 Labour authority; employment authority: The competent administrative units of the Ministry of Labour and Social Welfare that carry out inspection functions in matters of occupational safety and health, and the corresponding units of the federal states and of the Federal District, acting in support of them.
4.3 Workplace: The areas where construction work is carried out.
4.4 Contractor; builder: The natural or legal person that works temporarily on a construction site and contractually undertakes to the employer to carry out all or part of the work, according to the scope established in the project or contract, using its own or subcontracted equipment, machinery and/or labour.
4.5 Personal protective equipment (PPE): The set of items and devices for personal use to protect the worker from accidents and illnesses that could be caused by agents or factors generated in the course of performing their work activities, and which, depending on the risk to which workers are exposed, may be basic or specific. Where the risk analysis establishes the need to use work clothing with specific protective characteristics, that clothing shall be considered personal protective equipment.
4.6 Basic personal protective equipment: Those items and devices for personal use to protect the worker against the risks to which they are exposed during the performance of their construction activities.
4.7 Specific personal protective equipment: Those items and devices for personal use to protect the worker against additional risks to which they are exposed as a result of performing hazardous work.
4.8 Confined space: A place large enough, with deficient natural ventilation, configured in such a way that a person can perform a particular task inside it, that has limited or restricted means of access or egress, that is not designed to be occupied by a person on a continuous basis, and in which specific work is carried out occasionally.
4.9 Safety instructions: The description, in logical and sequential order, of the activities that workers shall follow during their activities to prevent risks or in cases of emergency on construction sites. These instructions may be contained in documents such as procedures, manuals or guides, among others.
4.10 Reference level: The surface considered as the base for measuring the height of the working plane.
4.11 Site; construction site: The demolition, excavation, foundation, building, installation, finishing and other activities.
4.12 Employer: The natural or legal person on whom rests the responsibility for carrying out the construction site, through the services of one or more workers under their charge.
4.13 Hazard: Situations in the working environment, determined by the characteristics or intrinsic properties of chemical or physical agents, or by unsafe conditions, in which harm may occur.
4.14 Site access permit: The authorisation document issued by the person in charge of the construction site, for entry to, and the management and performance of activities at, the site. It is granted to transporters, contractors and subcontractors.
4.15 Occupational safety and health policy: The reference framework for defining the occupational safety and health objectives and targets on the construction site, determined by the person in charge of the site to protect the life, physical integrity and health of the workers.
4.16 Construction site safety and health programme: The document containing the set of preventive and corrective actions to be implemented to avoid occupational risks on construction sites that could affect the life, physical integrity and health of the workers, or cause damage to their facilities. This instrument describes the activities, methods, techniques and safety conditions that shall be observed at each phase of the construction site, and shall, where applicable, be accompanied by specific safety manuals or procedures.
4.17 Supplier: The natural or legal person that provides services, materials and/or equipment to the employer.
4.18 Person in charge of the construction site: The employer or the person designated by them, with the authority to make decisions, among others, on the direction, performance and monitoring of occupational safety and health actions.
4.19 Risk: The correlation between the hazardousness of an agent or physical condition and the exposure of workers, with the possibility of causing adverse effects to their physical integrity, health or life, or of damaging the workplace.
4.20 Signage: The set of elements used in work areas to warn workers and external personnel of the location of emergency equipment or facilities; the existence of risks or hazards, as applicable; the performance of a mandatory action; or the prohibition of an act liable to cause a risk.
4.21 Preventive occupational safety and health services: Those provided by trained personnel, whether internal, external or mixed, whose main purpose is to prevent occupational accidents and illnesses through compliance with occupational safety and health regulations. Internal services are understood as those provided by the employer or the personnel of the construction site; external services, as those provided by personnel independent of the construction site; and mixed services, as those provided both by internal personnel and by personnel independent of those working on the construction site.
4.22 Severity of harm: The potential assessment of the impact that agents or unsafe conditions in the working environment may generate or cause, in terms of injury and damage to the worker or to the facilities.
4.23 Construction site safety and health system: The set of preventive occupational safety and health actions arising from the classification of the size of the site and the potential risks associated with the individual activities or the various phases of the construction site, together with its corresponding construction site safety and health programme.
4.24 Subcontractor: The natural or legal person that contractually undertakes to the contractor to carry out particular activities or phases of the construction site, using its own equipment, machinery and/or labour, according to the scope established in the contract.
4.25 Work at height: Maintenance, installation, demolition, operation, repair, cleaning and other activities carried out at heights greater than 1.80 m above the reference level. This also includes the risk of falling through openings in working surfaces, such as boreholes, pits, shafts and vertical tunnels.
4.26 Hazardous work: Work carried out on construction sites in which the worker is exposed to risks additional to those of the construction activities they perform, such as work carried out in excavations, confined spaces, at height, near electrical installations, roads or vehicle traffic routes, among others.
5. Obligations of the employer
5.1 To classify the size of the construction site as small, medium or large, in accordance with clause 7.1 of this Standard.
5.2 To have a description of the activities to be carried out, the risks faced by the workers and the list of safety measures to be adopted before and during their performance, in the case of small construction sites.
5.3 To have an analysis of potential risks: a) For medium-sized construction sites, on the basis of the provisions of clauses 8.1 and 8.3 of this Standard, or b) For large construction sites, for each of their phases, in accordance with clauses 8.2 and 8.3 of this Standard.
5.4 To have a construction site safety and health system: a) For medium-sized construction sites, in accordance with the provisions of clauses 9.1 and 9.2 of this Standard, or b) For large construction sites, in accordance with the provisions of clauses 9.1 and 9.3 of this Standard.
5.5 To have and follow up a programme for the review and preventive maintenance of the equipment and/or machinery used, in the case of medium-sized and large construction sites, which shall contain at least the activity to be carried out, the dates of performance and the person responsible for its execution.
5.6 To have safety procedures, in the case of medium-sized and large construction sites, for: a) The review and maintenance of the tools and equipment used by workers, which shall at least cover the activity to be carried out, the dates of performance and the person responsible for its execution, and b) The installation and management of temporary and permanent electrical installations.
5.7 To have safety instructions, in the case of medium-sized and large construction sites, for carrying out: a) Backfilling and compaction work; formwork fabrication and handling; concrete handling and placement and, where applicable, for carrying out two or more of these activities simultaneously, and b) Hazardous work.
5.8 To provide workers with the basic personal protective equipment corresponding to their job and, where applicable, the specific equipment corresponding to them, on account of carrying out hazardous work, on the basis of the provisions of Table 5 of this Standard, or of the risk analysis referred to in NOM-017-STPS-2008, or those replacing it.
5.9 To have procedures for the use, inspection, replacement, cleaning, limitations, maintenance, safekeeping and final disposal of personal protective equipment, based on the manufacturer's information and in accordance with NOM-017-STPS-2008, or those replacing it.
5.10 To supervise that workers wear the basic personal protective equipment and, where applicable, the specific equipment. In the case of medium-sized and large construction sites, visitors shall wear at least a safety helmet and, in addition, other types of equipment, based on the risk to which they are exposed.
5.11 To adopt the safety measures applicable to the activities to be carried out on the construction site, on the basis of the provisions of Chapters 11 to 18 of this Standard.
5.12 To have fire extinguishers to fight possible incipient fires, according to the type of fire that may occur in the different areas of the construction site, the inventories of substances and the materials used, in accordance with NOM-002-STPS-2010, or those replacing it.
5.13 To have protection systems and safety devices on the machinery and equipment used on the construction site, in accordance with the provisions of NOM-004-STPS-1999, or those replacing it.
5.14 To have, where applicable, the operating authorisations for the pressure vessels and steam generators used on construction sites, in accordance with NOM-020-STPS-2002, or those replacing it.
5.15 To have safety signage, on the basis of the provisions of NOM-026-STPS-2008, or those replacing it, to indicate the risks at each phase of the construction site and for the use of personal protective equipment.
5.16 To have an emergency response plan: a) For small construction sites, on the basis of the provisions of clause 19.1 of this Standard, b) For medium-sized construction sites, in accordance with the provisions of clause 19.2 of this Standard, or c) For large construction sites, in accordance with the provisions of clause 19.3 of this Standard.
5.17 To provide information to, and train, workers on occupational safety and health, in the case of medium-sized and large construction sites, in accordance with the provisions of Chapter 20 of this Standard.
5.18 To provide contractors, subcontractors and suppliers with information on the risks that may arise in the phase of the construction site where they will carry out their activities, in the case of medium-sized and large construction sites, so that they comply with the provisions of the construction site safety and health system.
5.19 To set up at least one safety and hygiene committee on the construction site and to supervise that it performs its functions, in accordance with the provisions of NOM-019-STPS-2011, or those replacing it.
5.20 To have preventive occupational safety and health services, on the basis of the provisions of NOM-030-STPS-2009, or those replacing it.
5.21 To authorise in writing the workers who carry out hazardous work, in the case of medium-sized and large construction sites, in accordance with the provisions of clause 9.4 of this Standard.
5.22 To grant contractors, subcontractors and suppliers the site access permits they require to enter and carry out their activities on the site.
5.23 To provide workers with a hygienic area for eating, in accordance with the provisions of the Official Mexican Standards issued in that regard by the Ministry of Health.
5.24 To provide workers with temporary drinking-water services and sanitary facilities - washbasins, toilets, urinals, among others - in accordance with the provisions of the Official Mexican Standards issued in that regard by the Ministry of Health, or with the local and environmental legislation on the matter.
5.25 To provide, as applicable, accommodation for workers on large construction sites, depending on the size, type and location of the construction site. Where the construction site has camps for accommodating workers, these shall be fitted out in accordance with the provisions of the relevant Official Mexican Standards of the Ministry of Health and, where applicable, with the provisions of the collective labour agreement.
5.26 To notify the Ministry of Labour and Social Welfare of the occupational accidents and illnesses that occur on the site, in accordance with the provisions of NOM-021-STPS-1993, or those replacing it.
5.27 To keep, on medium-sized and large construction sites, a record of information on the occupational accidents that occur, in accordance with Chapter 21 of this Standard.
5.28 To produce to the labour authority the documents that this Standard requires it to prepare or hold, when the labour authority so requires.
6. Obligations of the workers
6.1 To check, before the start of activities, through the personnel responsible for their use, that the machinery, equipment, tools and work implements are in safe and operational condition, and to report immediately to the employer any anomaly detected that endangers their use.
6.2 To carry out their activities in accordance with the instructions determined in the construction site safety and health system and in the authorisations to carry out hazardous work.
6.3 To use the personal protective equipment provided by the employer, the contractor or the subcontractor, in accordance with the procedures for use, inspection, replacement, cleaning, maintenance, safekeeping and final disposal.
6.4 To refrain from carrying out activities that could have, as a direct or indirect consequence, personal accidents and/or material damage, and that contravene the provisions of this Standard and those established by the employer.
6.5 To notify the employer immediately of incidents, accidents, unsafe conditions and acts, or actual or potential emergency situations detected during the performance of their activities.
6.6 To follow the instructions established by the employer under the emergency response plan.
6.7 To attend and participate, as applicable, in the occupational safety and health training or information provided to them by the employer.
6.8 To adequately safeguard the property that the employer makes available for the performance of their work or for the worker's convenience.
6.9 To participate in the safety and hygiene committee, or in the emergency response teams.
7. Classification of construction site size
7.1 Construction sites shall be classified in accordance with Table 1 below: Table 1 Classification of construction site size Size of the site Item
Small Medium Large
Surface area to be built or
demolished, in square Less than 350 From 350 to 10 000 More than 10 000
metres. Height of the construction,
Less than 10.5 From 10.5 to 16.5 More than 16.5
in metres.
7.2 For the classification of the construction site, the largest site size applicable to it shall be considered, on the basis of any of the following variables: the surface area to be built or demolished, in square metres, or the height of the construction, in metres.
8. Analysis of potential risks
8.1 The analysis of potential risks for medium-sized construction sites shall consider the following: a) The activities to be carried out or trades that will take part; b) The conditions of the facilities; c) The safety and operating conditions of the tools, equipment and machinery to be used; d) The identification of the hazards present; e) The analysis of workers' exposure to the hazards; f) The determination of the risks and their possible impact, based on the hazards present, in accordance with the hierarchy established in clause 8.3 of this Standard; g) The prevention, protection and control measures applicable to the risks detected, and h) The signature of the person in charge of the site.
8.2 The analysis of potential risks for large construction sites shall consider the following: a) The activities or work to be carried out at each phase of the construction site, on the basis of the site project; b) The conditions of the facilities; c) The safety and operating conditions of the tools, equipment and machinery to be used; d) The safety instructions; e) The risk factors present in the work activities; f) The possible causes of events leading to accidents, linked to the hazards previously identified; g) The analysis of workers' exposure to the hazards of the activities or phases of the site; h) The determination of the risks and their possible impact, based on the hazards present, in accordance with the hierarchy established in clause 8.3 of this Standard; i) The prevention, protection and control measures applicable to the risks detected, and j) The signature of the employer, of the person in charge of the site, or of the person in charge of the preventive occupational safety and health services.
8.3 The hierarchy of risk impact shall comprise: a) The category of frequency of occurrence of the risks, which is obtained by considering the possibility that they occur, associated with the site activities, as shown in Table 2 below: Table 2 Frequencies of occurrence of risks Frequency Definition Category Designation
b) The severity of the harm that the risk may cause, with its category and designation, obtained by considering the harm definitions established in Table 3 below: Table 3 Severity of harm Severity Definition Category Designation No harm, or harm involving temporary incapacity of the I Minor worker of three days or less. May involve temporary incapacity of the worker for more than II Moderate three days.
III Critical May involve permanent partial incapacity of the worker.
May involve total permanent incapacity or the death of the IV Fatal worker. c) The hierarchy of risk impact is obtained by associating the frequency of occurrence of the risk with the severity of the harm it may cause, in accordance with the provisions of Table 4 below: Table 4 Hierarchy of risk impact Severity of harm
Frequency of
risk
A Remote Minimal Minimal Minimal Low
Risks shall be ranked by their impact as serious, high, medium, low and minimal, which shall serve as the basis for establishing the order of priority for the prevention, protection and control measures to be adopted.
| A | Remote | That may occur exceptionally. |
| B | Isolated | That rarely occurs. |
| C | Occasional | That occurs infrequently. |
| D | Recurrent | That repeats periodically. |
| E | Frequent | That occurs regularly. |
I II III IV
Minor Moderate Critical Fatal
E Frequent Medium High Serious Serious D Recurrent Low Medium High Serious
occurrence of the C Occasional Minimal Low Medium High
B Isolated Minimal Minimal Low Medium8.3.1 Risks classified as serious shall be addressed immediately, to modify the safety conditions, the safety instructions, the personal protective equipment, or the training. High, medium and low risks shall then be addressed successively, and finally the minimal risks.
9. Construction site safety and health system
9.1 The construction site safety and health system shall be established before the construction site activities begin, and shall comprise the following: a) The occupational safety and health policy; b) The classification of the site (medium or large); c) The determination of the risks associated with the activities; d) The construction site safety and health programme containing the prevention, protection and control measures for those risks; e) The authorisation to carry out hazardous work, and f) The signature of the employer and/or of the person in charge of the construction site, and/or of the person in charge of the preventive occupational safety and health services.
9.2 The safety and health system for medium-sized construction sites shall comprise, in addition to the provisions of clause 9.1, the following: a) Information on the risk prevention, protection and control measures; b) The list of safety measures and instructions for the activities to be carried out on the site; c) Programmes for: 1) Training in occupational safety and health matters; 2) The selection, use and maintenance of basic and, where applicable, specific personal protective equipment; 3) The review and preventive maintenance of machinery, equipment, tools and safety devices, and 4) The supervision and monitoring of safety on the site; d) Safety instructions for the access and control of personnel on the site, applicable to workers, subcontractors, suppliers and visitors, which shall at least include working hours, the definition of entry to and exit from the work areas, the personal protective equipment to be used, and evacuation routes; e) The first-aid manual, and f) The emergency response plan, in accordance with the provisions of Chapter 19 of this Standard.
9.3 The safety and health system for large construction sites shall comprise, in addition to the provisions of clause 9.1, the following: a) The description of the site to be carried out: 1) Total construction area; 2) Technical data or the executive project: architectural and structural drawings, of plumbing, electrical and special installations, together with their corresponding technical calculation reports and schedule of items and/or location sketches, and 3) The location of the site and its surroundings; b) The description of temporary facilities: offices, warehouses, workshops, canteens, medical service, storage yards, equipment-washing areas, toilets, access points, perimeter protection, lighting, earthing connections and roadways, as applicable; c) The organisation chart of the site personnel and the responsibilities of the different levels, in occupational safety and health matters; d) The analysis of the potential risk of each activity, including the detection, evaluation and hierarchy of the hazards and risks associated with the main activities to be carried out during the performance of the work, in accordance with the construction site safety and health programme; e) Programmes for: 1) Training in occupational safety and health matters; 2) The selection, use and maintenance of basic and, where applicable, specific personal protective equipment; 3) The review and preventive maintenance of machinery, equipment, tools and safety devices, and 4) The supervision and monitoring of safety on the site by phases; f) Safety instructions for the access and control of personnel on the site, applicable to workers, subcontractors, suppliers and visitors, which shall at least include working hours, the definition of entry to and exit from the work areas, the personal protective equipment to be used, and evacuation routes; g) The first-aid manual, and h) The emergency response plan, in accordance with the provisions of Chapter 19 of this Standard.
9.4 The authorisations to carry out hazardous work shall contain at least: a) The name of the authorised worker; b) The type of work to be carried out and the area or place where the activity will be performed; c) The date and time of commencement of the activities, and the estimated completion time; d) The safety measures applicable in accordance with the results of the risk analysis for each activity, and e) The name and signature of the employer or of the person designated to grant the authorisation.
10. Selection of basic and specific personal protective equipment
10.1 Basic personal protective equipment shall be selected according to the job, and, where applicable, specific equipment according to the hazardous work to be performed, on the basis of the provisions of Table 5 of this Standard, or of the risk analysis referred to in NOM-017-STPS-2008, or those replacing it. Job titles cover the different categories of the trade.
10.2 Visitors entering medium-sized and large construction sites shall wear at least a safety helmet and, in addition, other types of equipment, based on the risk to which they are exposed.
10.3 The personal protective equipment used by workers and visitors shall, where applicable, bear the certification issued by a certification body accredited and approved under the Federal Act on Metrology and Standardisation, or the manufacturer's guarantee that it protects against the risks for which it was manufactured. Table 5 Selection of personal protective equipment PERSONAL PROTECTIVE EQUIPMENT 4 (RESPIRATORY 5 (UPPER
1 (HEAD) 2 (EYES AND FACE) 3 (EARS) APPARATUS) LIMBS)
B) RESPIRATOR AGAINST GASES AND A) GLOVES AGAINST SUBSTANCES
A) IMPACT-PROTECTION HELMET A) SAFETY GLASSES D) WELDER'S FACE SHIELD C) DISPOSABLE FACE MASK D) SELF-CONTAINED BREATHING C) GLOVES AGAINST
B) DIELECTRIC GLOVES JOB C) HOODS OR BALACLAVAS A) RESPIRATOR AGAINST B) EAR MUFFS No.
B) DIELECTRIC HELMET E) WELDING GOGGLES A) EAR PLUGS
TITLE 1/ C) FACE SHIELD
B) GOGGLES PARTICULATES VAPOURS APPARATUS CHEMICALS EXTREME TEMPERATURES D) GLOVES E) SLEEVES
INSTALLER OF
5 FLOOR FINISHES B B B B B
AND WALLS INSTALLER OF
6 B S B
INSULATION MATERIAL INSTALLER OF
7 MOSAICS AND B B B B B
TILES INSTALLER OF
8 GLASS AND B B B
GLAZING INSTALLER OF
9 PRODUCTS B S B S B S S B
PRECAST DRIVER OF 10 B LORRY DRIVER-
11 OPERATOR OF B
HEAVY EQUIPMENT DRIVER- OPERATOR OF 12 B SPECIALISED EQUIPMENT DRIVER- OPERATOR OF
13 B S S
CRANE VEHICLES ELECTRICIAN AND
14 INSTALLER OF B B B S B
ELECTRICAL LINES PERSONAL PROTECTIVE EQUIPMENT 4 (RESPIRATORY 5 (UPPER
1 (HEAD) 2 (EYES AND FACE) 3 (EARS) APPARATUS) LIMBS)
B) RESPIRATOR AGAINST GASES AND A) GLOVES AGAINST SUBSTANCES
A) IMPACT-PROTECTION HELMET A) SAFETY GLASSES D) WELDER'S FACE SHIELD C) DISPOSABLE FACE MASK D) SELF-CONTAINED BREATHING C) GLOVES AGAINST
B) DIELECTRIC GLOVES JOB C) HOODS OR BALACLAVAS A) RESPIRATOR AGAINST B) EAR MUFFS No.
B) DIELECTRIC HELMET E) WELDING GOGGLES A) EAR PLUGS
TITLE 1/ C) FACE SHIELD
B) GOGGLES PARTICULATES VAPOURS APPARATUS CHEMICALS EXTREME TEMPERATURES D) GLOVES E) SLEEVES
15 STEEL FIXER B S B B S B
BLACKSMITH-
16 B B B B B
FORGER INSTALLER OF
17 LINES B S B S S
TELECOMMUNICATIONS MECHANIC OF
18 B B S B
HEAVY EQUIPMENT MECHANIC OF
19 INSTRUMENTS B S B S S
INDUSTRIAL INSTALLATION MECHANIC OF
20 LIFTS AND B S B S S
ELECTRIC ESCALATORS INSTALLATION MECHANIC OF
21 B S B S B
INDUSTRIAL MACHINERY ERECTOR OF
22 STRUCTURES B S B S B
METAL OPERATOR OF EQUIPMENT OF
23 S B B B B B
SHOT-BLASTING (SANDBLASTING) DRILLER WITH
24 B B B B B
AIR GUN PERSONNEL OF THE SERVICES
25 PREVENTIVE B S
OCCUPATIONAL SAFETY AND HEALTH TECHNICAL- 26 S ADMINISTRATIVE PERSONNEL OF
27 B B B B B
CLEANING
28 PAINTER B B B S B
PLUMBER AND
29 INSTALLER OF B B S B
PIPES WELDER WITH
30 B B B B B B S B B B
ELECTRIC ARC WELDER WITH
31 B B B B B S B B
GAS (OXY-FUEL) EQUIPMENT SUPERVISOR OF
32 B S B B S S
SITE SURVEYOR AND 33 B CHAINMAN WATCHMAN, SECURITY GUARD
34 OR GUARD OF B
SECURITY PLASTERER AND
35 B S S B
RENDERER 1/ Covers the different categories of the trade. B.- Basic personal protective equipment. S.- Specific personal protective equipment. Cont...Table 5 Selection of personal protective equipment PERSONAL PROTECTIVE EQUIPMENT
6 (TRUNK) 7 (LOWER LIMBS) 8 (OTHER)
C) FOOTWEAR AGAINST SUBSTANCES B) APRON AGAINST SUBSTANCES A) IMPACT-PROTECTION FOOTWEAR D) CLOTHING AGAINST SUBSTANCES A) PROTECTIVE EQUIPMENT A) APRON AGAINST HIGH
B) DIELECTRIC FOOTWEAR E) WATERPROOF BOOTS B) REFLECTIVE VEST No. JOB TITLE 1/
C) BELT FOR
CHEMICALS CHEMICALS HAZARDOUS CHEMICALS D) GAITERS AGAINST FALLS FROM HEIGHT D) PROTECTIVE HOOD TEMPERATURES C) SMOCK TOOLS
INSTALLER OF
5 FLOOR FINISHES AND B S
WALLS INSTALLER OF
6 B S B
INSULATION MATERIAL INSTALLER OF
7 B S
MOSAICS AND TILES INSTALLER OF
8 B S S
GLASS AND GLAZING INSTALLER OF
9 PRODUCTS B S S S
PRECAST DRIVER OF
10 B B
LORRY DRIVER-
11 OPERATOR OF EQUIPMENT B B
HEAVY DRIVER- OPERATOR OF
12 B B
SPECIALISED EQUIPMENT DRIVER-
13 OPERATOR OF B S B
CRANE VEHICLES ELECTRICIAN AND
14 INSTALLER OF LINES B B S B S
ELECTRICAL
15 STEEL FIXER B S S B S 16 BLACKSMITH-FORGER B B S B S
INSTALLER OF LINES
17 B S S B S
OF TELECOMMUNICATIONS MECHANIC OF EQUIPMENT
18 B S B S
HEAVY MECHANIC OF
19 INSTRUMENTS B S S B S
INDUSTRIAL INSTALLATION MECHANIC OF LIFTS AND
20 B S S B S
ELECTRIC ESCALATORS INSTALLATION MECHANIC
21 OF MACHINERY B S B S
INDUSTRIAL ERECTOR OF
22 STRUCTURES B S B S
METAL OPERATOR OF EQUIPMENT
23 OF SHOT-BLASTING B B B
(SANDBLASTING) DRILLER WITH
24 B S B S
AIR GUN PERSONNEL OF THE SERVICES
25 PREVENTIVE B B
OCCUPATIONAL SAFETY AND HEALTH PERSONAL PROTECTIVE EQUIPMENT
6 (TRUNK) 7 (LOWER LIMBS) 8 (OTHER)
C) FOOTWEAR AGAINST SUBSTANCES B) APRON AGAINST SUBSTANCES A) IMPACT-PROTECTION FOOTWEAR D) CLOTHING AGAINST SUBSTANCES A) PROTECTIVE EQUIPMENT A) APRON AGAINST HIGH
B) DIELECTRIC FOOTWEAR E) WATERPROOF BOOTS B) REFLECTIVE VEST No. JOB TITLE 1/
C) BELT FOR
CHEMICALS CHEMICALS HAZARDOUS CHEMICALS D) GAITERS AGAINST FALLS FROM HEIGHT D) PROTECTIVE HOOD TEMPERATURES C) SMOCK TOOLS
TECHNICAL- 26 B ADMINISTRATIVE
27 CLEANING PERSONNEL B S S B 28 PAINTER S B S S B
PLUMBER AND
29 INSTALLER OF B S B S
PIPES WELDER WITH ARC
30 B B B B S B
ELECTRIC WELDER WITH
31 B B B S B
GAS (OXY-FUEL) EQUIPMENT
32 SITE SUPERVISOR B S B
SURVEYOR AND
33 B B
CHAINMAN WATCHMAN, SECURITY GUARD OR
34 SECURITY OFFICER OF B
SECURITY
1 (HEAD) 2 (EYES AND FACE) 3 (EARS)
APPARATUS) LIMBS) A) IMPACT-PROTECTION HELMET A) SAFETY GLASSES D) WELDER'S FACE SHIELD C) DISPOSABLE FACE MASK
D) SELF-CONTAINED BREATHING C) GLOVES AGAINST1 BRICKLAYER B S B S S S S S 2 STOREKEEPER B B 3 VARNISHER B B B S B 4 CARPENTER B B B B
1 (HEAD) 2 (EYES AND FACE) 3 (EARS)
APPARATUS) LIMBS) A) IMPACT-PROTECTION HELMET A) SAFETY GLASSES D) WELDER'S FACE SHIELD C) DISPOSABLE FACE MASK
D) SELF-CONTAINED BREATHING C) GLOVES AGAINSTB) DIELECTRIC FOOTWEAR E) WATERPROOF BOOTS B) REFLECTIVE VEST No. JOB TITLE 1/
CHEMICALS HAZARDOUS CHEMICALS CHEMICALS D) GAITERS AGAINST FALLS FROM HEIGHT D) PROTECTIVE HOOD
TEMPERATURES C) SMOCK TOOLS1 BRICKLAYER B S S S B 2 STOREKEEPER B B 3 VARNISHER S B S 4 CARPENTER B S B S
15 STEEL FIXER B S S B S 16 BLACKSMITH-FORGER B B S B S
B) DIELECTRIC FOOTWEAR E) WATERPROOF BOOTS B) REFLECTIVE VEST No. JOB TITLE 1/
CHEMICALS HAZARDOUS CHEMICALS CHEMICALS D) GAITERS AGAINST FALLS FROM HEIGHT D) PROTECTIVE HOOD
TEMPERATURES C) SMOCK TOOLS27 CLEANING PERSONNEL B S S B 28 PAINTER S B S S B
35 PLASTERER AND RENDERER B S 1/ Covers the different categories of the trade. B.- Basic personal protective equipment. S.- Specific personal protective equipment.
11. Excavation work
11.1 On construction sites where excavation work is carried out, an analysis of potential risks shall be in place that considers, in addition to the provisions of clauses 8.1 or 8.2 of this Standard, as applicable, the following: a) The soil mechanics study, addressing the type of soil to be excavated, its physical composition and mechanical properties; b) The presence of services near the excavation: live lines, pipes, ducts and other infrastructure networks; c) Weather changes; d) The cutting depth; e) The method for stabilising the excavation slopes, where applicable; f) The equipment, machinery and tools to be used; g) The type and quantity of explosives to be used, where applicable, and h) The process of removal, loading, haulage and slope stability.
11.2 During excavation activities, the following safety measures shall be adopted: a) Inspect the excavation site to detect potential faults, cracks or collapses: 1) At the start of each shift and on completion of the work, to detect changes in the ground; 2) After heavy rain; 3) After the passage of heavy machinery or intense vehicle traffic, and 4) On conclusion of any event that could increase the risk; b) Inspect, at the start and end of each shift, the systems used to stabilise the walls of trenches; c) Prohibit workers from remaining inside the trench while the excavation machinery is in operation; d) Remove trees, bushes and shrubs that hinder the stability of the ground cuts to be made, provided the relevant authorisations are held; e) Secure the supports or anchors of electrical power poles or, where applicable, request their relocation from the competent authority; f) Reinforce the walls of the excavation with props, linings, mesh, platforms, formwork, crosspieces or shoring (sheet piling), where there is a risk of collapse. In excavations for piles, prohibit the entry of workers where the walls of the excavation lack due protection; g) Carry out excavations at work faces with stable slopes, the inclination of which shall be in accordance with the type of soil and/or Table 6 below: Table 6 Maximum inclination of excavation slopes Maximum inclination for excavations Type of soil or rock less than 6m deep Stable rock Vertical (90°) Type A ¾ : 1 (53°) Type B 1 : 1 (45°) Type C 1 ½ : 1 (34°) h) Stabilise the walls of the trench with elements extending 20 cm above the ground surface, where its depth is greater than 1.50 m; i) Install support systems to ensure the stability of adjoining buildings, boundary walls or other structures adjacent to the excavation; j) Provide, in trench excavations 1.20 m or more in depth, a ladder or ramp for workers to enter and exit. The ladder shall project 90 cm above the highest part of the trench and shall be placed at a maximum horizontal distance of 7 m from the work site; k) Keep machinery and equipment, in particular those fitted with a boom, lifting equipment and similar items, at a minimum safety distance when located near overhead electric power distribution lines, in accordance with Table 7 below: Table 7 Minimum safety distance of equipment and machinery from electric power lines Voltage (phase to phase) Minimum safety distance (V) (m) Up to 50 000 3.10 Up to 73 000 3.33 Up to 85 000 3.45 Up to 115 000 3.75 Up to 140 000 4.00 Up to 230 000 4.90 Up to 400 000 6.60 Up to 600 000 8.60 l) Provide separate access routes for circulation, one for workers and another for machinery and lorries. Where this is not possible, the access shall be delimited with physical barriers; m) Provide walkways or bridges at the edge of the excavation; n) Signpost and delimit the perimeter of excavations with hazard tape or protective mesh, where the depth is less than 1.5 m, and with rigid barriers 90 cm high, for those with a depth greater than 1.5 m; o) Limit access to the trench to a safety distance measured from the vertical plane of the trench wall, to be determined in accordance with the outcome of a study that addresses, at least, the type of soil or rock; the width and depth of the trench; the maximum loads of the machinery, vehicles or stockpiled materials; and the shoring in the trench, where applicable; p) Provide lighting appropriate to the work shift; q) Use portable equipment supplied at 24 volts, where the use of electrical wiring poses a risk to the installation of artificial lighting; r) Avoid stockpiling materials or soil less than 2 m from the edge of the excavation, so as not to impose overloads on the ground; s) Keep the excavation open for the shortest possible time; t) Notify the supervisor of the presence of electrical wiring and mark its location; u) Carry out air-quality sampling where an excavation becomes a confined space and hazardous atmospheres are present, such as the presence of gases or lack of oxygen, among others, whatever its depth, and, where applicable, install a ventilation system; v) Suspend excavation work where there is an accumulation or rise in the water level, and remove it immediately to prevent the stability of the slopes from being altered, using the equipment available for that purpose, and w) Have safety measures in place for the use of explosives, activities that shall be carried out in accordance with the regulations issued for that purpose by the Ministry of National Defence.
11.3 For trench shoring, the following safety measures shall be adopted: a) Select the shoring design according to the time it will be used for, the resistance of the soil and the materials to be used; b) Avoid simultaneous shoring work at different levels on the same vertical plane; c) Discard props that are open or splintered; d) Mark or place barriers and warning signs in high-voltage areas; e) Make electrical connections using weatherproof sealed mechanisms, and f) Prohibit workers from descending into or climbing out of the trench using the props.
12. Work in confined spaces
12.1 For activities to be carried out in confined spaces, a risk analysis shall be in place, comprising at least the following: a) The description of the activity to be carried out; b) The conditions of the place where the activity will be carried out; c) The machinery, tools and equipment to be used; d) The risks of the materials and/or substances to be used (toxicity, flammability, reactivity or specific risks); e) The list of possible hazardous conditions and risks; f) The estimated duration of the activities to be carried out, and g) The effects of oxygen concentration in confined spaces, in accordance with Table 8 below: Table 8 Effects of oxygen concentration in confined spaces % oxygen Effects
21.0 ¾ No effects.
19.5 ¾ Lower limit with no effects for 8 hours.
18.0 ¾ Muscular coordination problems. ¾ Acceleration of the respiratory rate.
17.0 ¾ Motor impairment. ¾ Risk of loss of consciousness.
16.0 ¾ Disorientation of the worker. ¾ Impaired breathing. ¾ Dizziness. ¾ Headache.
14.0 ¾ Impaired judgement of the worker. ¾ Rapid fatigue.
8.0 ¾ Mental impairment in the worker. ¾ Nausea. ¾ Vomiting. ¾ Loss of consciousness.
6.0 ¾ Difficulty breathing. ¾ Convulsive movements. ¾ Death within minutes.
12.2 For activities to be carried out in confined spaces, the following shall be in place: a) The safety procedures for the activities to be carried out and for the equipment and tools to be used; b) The sampling procedures for detecting hazardous atmospheres or oxygen deficiency; c) A specific work plan in case adverse atmospheric conditions persist in that space; d) The rescue plan for possible casualties in the confined space, including the rescue equipment for emergencies; e) The signage at the entrance to the confined space; f) The person in charge of supervising the work, who shall be located outside the confined space; g) The personal protective equipment required. Where the oxygen level inside the confined space is equal to or less than 19.5 per cent, workers shall be provided with airline equipment or self-contained breathing apparatus; h) Natural or forced ventilation systems to maintain a respirable atmosphere at all times. It is prohibited to use compressed air as a source of ventilation in a confined space; i) Lighting inside confined spaces in the presence of flammable or explosive materials or substances, on the following basis: 1) Luminaires with low-voltage safety ratings, up to 24 volts, and 2) Explosion-proof, heavy-duty lamps; j) Tools and electrical equipment requiring more than 12 volts to operate shall, in explosive atmospheres, be fitted with a residual-current earth-fault circuit breaker, connected to a physical earth. The switch, the transformer and other circuit elements shall be located outside the confined space; k) The communication mechanisms between the personnel operating inside the confined space and the supervising personnel; l) The control of personnel entering and leaving the confined space, by means of the corresponding authorisation, which shall remain at the entrance while the activities are being carried out; m) The record of the length of time workers remain inside the confined space, where applicable, with variable rest breaks according to the temperature conditions of the working atmosphere, the work regime and the worker's body temperature, and n) Continuous atmospheric sampling, where work is carried out in confined spaces with flammable, explosive or toxic liquids, or atmospheres with oxygen deficiency.
12.3 The authorisations for entry into confined spaces shall contain at least the following information: a) The place where the activity will be carried out; b) The date on which the work will be performed; c) The name and signature of the personnel authorised to enter; d) The name and signature of the person in charge of the area where the activity will be carried out, and e) The name and signature of the person granting the authorisation.
12.4 The rescue plan shall be reviewed with all personnel entering confined spaces and with relief personnel, and shall contain at least the following: a) The description of the different emergencies that could arise; b) Who to ask for help in an emergency, and how; c) Instructions on how to assist one or more persons in an emergency, and d) The procedure for assisting personnel using self-contained breathing apparatus.
12.5 All welding and cutting activities that need to be carried out in the confined space, in addition to the provisions of clause 12.2, shall meet the following safety conditions: a) Ventilate the inside of the confined space so that no flammable or explosive atmospheres are present; b) Have a forced air extraction and recirculation system to prevent welding fumes; c) Have at least one ABC-type fire extinguisher of a capacity matching the materials and type of fire that could occur; d) Use the personal protective equipment required for the activity, the job and the place where it will be carried out; e) Have, where applicable, screens to delimit the areas where welding or cutting activities are carried out; f) Locate welding machines and cylinders outside the confined space; g) Check the cables and connections before they are brought into the confined space; h) Use pressure regulators, gauges and flashback-arrestor valves in safe and operational condition; i) Use crimped-type connections on hoses, and j) Check the hoses and connections before they are brought into the confined space to prevent possible leaks.
13. Welding and cutting
13.1 Welding and cutting activities shall be carried out in accordance with the provisions of NOM-027-STPS-2008, or those replacing it, and the provisions contained in this chapter.
13.1.1 To protect workers carrying out electric welding work and personnel passing near where such activities are carried out, the following safety measures shall be adopted: a) Check that the welder's face shield or welding goggles have no openings and that the anti-radiation shade lens is the one specified; b) Place screens or shields around the welding station for the entire duration of the activity; c) Check that the cables do not cross a traffic route, such as walkways and stairs, and that they are protected by compression-resistant crossing supports and are fully extended; d) Keep flammable and combustible materials at a minimum distance of 10 m; e) Prohibit the use of clothing stained with grease, solvents or any other substance liable to catch fire; f) Prevent work from being carried out where the area is wet, or, failing that, insulate the area on a wooden base; g) Avoid pulling the cables, even where they become caught or offer resistance to handling; h) Disconnect the machine on completion of the work, collect the cables and store them in a dry place, and i) Remove the materials and leave the work area clean at the end of the shift.
13.1.2 For electric welding activities, the following safety measures shall be adopted: a) Have pliers, hooks, tongs or any other means available for handling the materials on which the welding work is performed; b) Place, where applicable, the parts to be welded on a table or area with a base of insulating or heat-dispersing, fire-resistant material; c) Check the insulation of the electrical cables at the start of the shift and discard those showing cracking and direct connections protected with insulating tape; d) Check that the electrode holders and connection terminals are insulated and in safe and operational condition; e) Keep electric-arc welding machines as far away as possible from the site of the operation and also from furnaces or other heat sources; f) Control the generation of sparks during and at the end of welding work, where applicable, by installing screens or fire-retardant blankets; g) Prevent cables from resting on hot objects, puddles, sharp edges or any other place that could damage the insulation; h) Monitor the atmosphere with an explosimeter during welding work carried out in enclosed spaces; i) Clean welding residues with a wire brush or hammer; j) Prohibit electrode holders from being placed in water to cool them; k) Suspend outdoor welding work in the event of rain or where clothing becomes wet from sweat or another liquid; l) Disconnect the equipment before making voltage changes and do not leave the holder directly on the ground or on structural steelwork, and m) Fully disconnect the equipment whenever it is removed from the work site, including to move it.
13.1.3 For oxy-acetylene cutting activities, the following measures shall be adopted: a) Have procedures for the handling and operation of cylinders, valves, regulators, hoses and their connections, as well as electrical power sources; b) Keep the area clean and tidy during and on completion of the activity; c) Ensure that flashback-arrestor valves are fitted between the torch handle and the hoses, and between the hose and the regulator, for both the oxygen and the acetylene; d) Check that there is no evidence of deformation, cracks or fractures in the cylinders, valves, regulators and hoses; e) Position the cutting equipment at least 3 m from the work site; f) Check that the cylinders: 1) Have caps fitted when stored or out of use; 2) Are stored vertically and secured with a chain; 3) Are not used to hang the torch, even when it is switched off; 4) Are moved on a trolley specifically designed for that purpose, firmly secured with a chain to prevent them falling; 5) Are not heated following flashback or a fire at the tap, and 6) Are moved for replacement by rotating them on their own base, and not rolled horizontally or dragged; g) Check that the regulators: 1) Have threads or fittings matching those of the valve outlet. Connections that do not match shall never be forced; 2) Are fitted with calibrated gauges in safe and operational condition; 3) Have dials, indicator needles, mica or protective glass, and 4) Are not interchanged or fitted onto others not designed for the type of cylinder used; h) Check that high-pressure oxygen gauges are fitted with safety caps and marked with the word OXYGEN and a green marking, and that acetylene gauges are marked with the word ACETYLENE with a red marking; i) Check that the hoses: 1) Have crimped or pressure connections for joining them to the torch and regulator handles; 2) Are protected with compression-resistant crossing supports where they cross vehicle or pedestrian traffic routes, and 3) Do not come into contact with hot surfaces, sharp edges, sharp corners or sparks; j) Prohibit, during the activities: 1) Striking the torch against any structure; 2) Smoking while handling the torches, and 3) Using oxygen to clean or blow out parts and pipework or to ventilate a room.
14. Work at height
14.1 Work at height shall be carried out in accordance with the provisions of NOM-009-STPS-2011, or those replacing it, and shall additionally comply with the conditions set out in this chapter.
14.1.1 To carry out work at height, the following safety measures shall be applied: a) Be supervised by a person with knowledge of fall protection on the construction site; b) Prevent different workers from working on the same vertical plane at different heights and, where this is unavoidable, adopt specific safety measures for such activities; c) Prohibit access by persons unconnected with the work area; d) Record and report immediately to the person in charge of the site and/or the safety personnel any damage or defects identified in the systems or equipment used for work at height, and e) Keep available on the construction site the records of inspections of the systems or equipment used for work at height.
14.1.2 For the use of tower- or structure-type scaffolding, the following safety measures shall be adopted: a) Have rigid barriers on platforms that open inwards or upwards to safeguard access to the scaffold stairways; b) Protect the work area and the access route around the scaffold against objects or tools falling from the working platform, and c) Prohibit, on scaffolding: 1) The use of electrical cable trays as platforms; 2) The installation on them of material hoists, unless they are designed or reinforced to bear an additional load; 3) The use of stepladders, barrels, drums, concrete blocks and other objects as part of their structure, and 4) The use of roof gutters, drains, pipe supports, lightning conductors or conductors as elements for securing them.
14.1.3 For the use of suspended scaffolding, the following safety measures shall be adopted: a) Carry out a documented load test at ground level before work begins; b) Place mesh around the perimeter of the platform, where materials or tools present a risk of falling; c) Establish tie-off points on the vertical faces; d) Check that the gap between the front face of the platform and the vertical face being worked on is no greater than 30 cm; e) Check that there are no cables or obstructions that could overload or tilt the scaffold, and f) Prohibit the use of planks as walkways between platforms of suspended scaffolding.
14.1.4 For the use of harnesses and lifelines, the maximum number of workers anchored to the same point shall be limited according to the strength of that anchor point and the design and construction characteristics established by the manufacturer.
14.1.5 For the use of aerial lift platforms, the following safety measures shall be met: a) Be operated only by qualified personnel; b) Place a tag (see Figure 1) in a visible place at the access point, attached in such a way as to prevent accidental removal, indicating the condition of use and the date and name of the person who inspected it; Figure 1 Examples of information tags on the condition of the platform c) Have signage, in accordance with the manufacturer's specifications, indicating: 1) The maximum weight to be supported; 2) The operating radii, and 3) The maximum number of persons it can bear; d) Have the stabilisers extended and the equipment level before raising the basket; e) Be free of personnel around it while it is in operation; f) Be capable of being operated directly, at any time, by means of dual operating-control systems; g) Operate the carrier only when the surface of the platform on which it rests is level and firm; h) Secure the platform to the structure where the platform is accessed from elevated places. Before personnel descend from the basket, they shall clip on to a fall-protection system, and i) Prohibit moving the carrier with the arm extended or with personnel inside the platform.
14.1.6 For the use of portable ladders on construction sites, the following safety measures shall be met: a) Ensure that both the lower and upper access areas are kept clean and clear of any material; b) Check, before use, that: 1) They are in safe and operational condition; 2) The rungs or side rails show no damaged, bent, dented or broken elements, and 3) The non-slip feet are not worn or broken; c) Prohibit the carrying of loads while ascending or descending the ladder, and d) Prevent them from being placed above moving mechanisms.
15. Transport of materials on construction sites
15.1 The employer shall keep a record of the site access permits for the transport of materials on construction sites, with the description of the activities to be carried out and the type of vehicles, machinery and self-propelled mobile equipment to be used, whether owned or subcontracted.
15.2 Operators of vehicles, machinery and self-propelled equipment for the transport of materials shall: a) Hold the corresponding site access permit to enter the sites; b) Carry out a visual inspection of the road conditions on winding and unstable terrain and, where applicable, carry out or request the necessary conditioning work before travelling on it; c) Apply the user manual for loading, unloading and manoeuvres, established for that purpose, so as not to exceed the load capacity of the unit. The manual shall be available in the Spanish language on board the equipment; d) Check that the load is properly positioned, secured and marked; e) Wear the seat belt while on board; f) Be trained and instructed in the emergency procedures and in controlling leaks or spills of the hazardous substances or materials being transported; g) Periodically check the general mechanical condition, bodywork, brakes, lights, tyres and integrity of the safety devices - switches, guards, protective devices, among others - and record the results in a logbook established for that purpose, and h) Report to the supervisor or person in charge of the site, for repair, any faults detected during the periodic inspection that compromise the safety of workers and facilities.
15.3 On construction sites, the transport of personnel on the running boards, mudguards, beds, buckets or scoops of vehicles, machinery and self-propelled mobile equipment used for transporting materials shall be prohibited, as well as on any other part not specifically designed for transporting personnel.
15.4 Vehicles, machinery or self-propelled equipment used for transporting materials on construction sites shall have the following: a) Audible devices - reversing alarms - to warn of reversing; b) Personnel to assist operators with reversing manoeuvres, and c) Safety devices, where applicable, such as cabs, belts, seat cushioning systems, or any other visual (beacon) or audible warning, identification or alarm device required according to the type of work to be carried out.
15.5 Construction sites shall have inspection and maintenance programmes for the vehicles, machinery or self-propelled equipment used for transporting materials.
15.6 Vehicles, machinery or self-propelled equipment used for transporting hazardous materials or substances in containers shall be fitted with attachments that prevent the free movement of such containers, and with the corresponding signage identifying their hazards.
15.7 It shall be ensured at all times that vehicles, machinery or self-propelled equipment used for transporting materials observe the safety distance referred to in clause 11.2, item o), of this Standard.
15.8 Manoeuvres with vehicles, machinery or self-propelled equipment used for transporting materials that are carried out at critical points on the site, with narrow or busy accesses, in the presence of energised or pressurised equipment, or in complex reversing operations, shall be carried out with the assistance of personnel providing the operator with the appropriate safety signals.
15.9 Tipper trucks shall be prohibited from travelling with the bed raised and, when loaded with soil, gravel or sand, such materials shall be covered with a tarpaulin.
15.10 Roads, access routes and truck beds shall be sprayed with water to prevent the formation of dust clouds.
15.11 Wheel stops shall be installed at the edges of slopes and fill embankments to prevent vehicles from reversing over them.
15.12 Safety signage for the movement of vehicles, machinery and self-propelled mobile equipment shall be placed on the basis of the ground conditions, visibility or weather conditions.
15.13 The priority for vehicle movement within the site shall be established as follows: a) Emergency and rescue vehicles; b) Official vehicles of the authorities; c) Vehicles/equipment climbing very steep gradients; d) Vehicles dedicated to transporting personnel, and e) Vehicles dedicated to transporting materials.
16. Specific work on construction sites
16.1 The minimum safety conditions for the installation of debris chutes; the performance of demolition work; pile driving; the installation of sanitary pipework; the handling of energised equipment or installations; formwork fabrication and handling; concrete handling and placement; slab tile laying; the performance of sandblasting cleaning work; the application of paint, varnish or coatings; the installation of glazing; and other specific work carried out on construction sites, shall be subject to the provisions of this chapter and the other clauses of this Standard. For the performance of other specific work not covered by this Standard, the employer shall determine the safety measures to be adopted to protect the workers.
16.2 For the installation of debris chutes, the following safety measures shall be adopted: a) Delimit and signpost the chutes and the area where debris is discharged; b) Fit guard rails at facade openings, light wells or other openings through which debris is discharged; c) Fit protective guard rails at the debris-discharge openings; d) Secure the debris chute to the structure; e) Position the lower end of the debris chute at an angle; f) Continuously wet the area where debris falls, and g) Provide ramps to allow easy movement of wheelbarrows.
16.3 For the performance of demolition work, the following safety measures shall be observed: a) Investigate the existence of gas, electrical power and water installations, or induced works, for their disconnection; b) Delimit and signpost the area where demolition work will be carried out; c) Remove all glass and glazing present in the structure to be demolished; d) Shore the supporting structure and unstable points with sandbags, where work is carried out under load; e) Designate a single location for the fall of removed material; f) Enclose the area with screens, partitions, hoardings or barriers; g) Limit workers' exposure to dust by means of: 1) Delimiting the work area and informing workers of the presence of hazardous substances or materials; 2) Decontaminating elements containing hazardous substances, and 3) Watering at suitable intervals the structures being demolished to prevent the formation of dust clouds; h) Prevent operatives from working at different levels on the same vertical plane; i) Begin demolition from top to bottom, seeking to maintain a horizontal line; j) Prevent the support points of structures holding up floors from being weakened while the work has not been completed; k) Dismantle metal structures floor by floor; l) Continuously remove debris so that access routes and work areas do not become obstructed, and to prevent overloading the structure; m) Discharge debris using discharge chutes for that purpose, and n) Halt demolition work in the event of strong winds or rain.
16.4 For pile driving, the following safety measures shall be adopted: a) Level and compact the work area for the pile-driving machine and concrete-delivery trucks; b) Chock stored piles to prevent them from rolling; c) Tie piles with ropes for unloading and prohibit workers from guiding them by hand; d) Protect all transmission mechanisms with housings; e) Keep the steps and access points to the pile-driving machine free of mud or grease; f) Prohibit piles from being dragged or pulled at an angle to bring them close to the driving location; g) Protect the reinforcement bars of the pile caps or heads; h) Prevent operatives from remaining close to the piling machine in a way that they could be struck by it or by the shafts in suspension; i) Prohibit unauthorised persons from accessing the piling machine or remaining near the cab or manoeuvring areas, and j) Secure a radius of 10 m around the piling machine to prevent impacts and being run over.
16.5 For the installation of sanitary pipework, the following safety measures shall be adopted: a) Delimit and signpost the work area, in accordance with clause 11.2, item n), of this Standard; b) Couple the pipes for the pipelines on a horizontal surface, chocked with wooden wedges, to prevent them from slipping or rolling; c) Cover or protect manholes immediately after building them; d) Install collective protection along open trenches; e) Keep the area illuminated; f) Suspend, at their ends, using slings, lifting lugs or balancing beams, pipe sections greater than 1.5 m in diameter; g) Place pipes and/or materials 2 m from the upper edge of the excavation; h) Carry out shoring with timber or other material on the sides of the excavation or trench; i) Prevent stockpiling at a distance of less than 2 m from the edge of the trench; j) Guide the placement of pipes in trenches from outside; k) Prohibit workers from remaining inside the excavation while pipe is being placed by crane, and l) Suspend work in the presence of rain.
16.6 For the performance of work involving the handling of energised equipment or installations, the following safety measures shall be observed: a) Delimit and signpost the work areas; b) Use tools protected with insulating material; c) Ensure that the routing of electrical supply lines does not coincide with that of temporary water-supply lines; d) Establish the energy-isolation procedure by means of tags and locks, and the use of dielectric personal protective equipment (gloves, footwear and helmet); e) Inform the site personnel about the performance of functional tests on the electrical installation and the energy-isolation procedure; f) Fit moisture- and dust-proof outdoor sockets; g) Signpost the electrical panels; h) Use portable wooden or fibreglass ladders to carry out electrical network installation work; i) Avoid, in wet areas, the handling of electrical installations, the use of portable electric tools or extension leads, or the performance of electric welding, and j) Prevent workers from wearing metal objects such as rings, chains, watches and earrings when carrying out activities on electrical installations or equipment.
16.7 For formwork fabrication and handling, the following safety measures shall be adopted: a) Provide signage for the mandatory use of personal protective equipment in the area where formwork operations are carried out; b) Fit nets, guard rails and signage at openings in the formwork to prevent workers from falling; c) Have workers ascend to and descend from the formwork by means of auxiliary equipment such as baskets, hoists or ladders; d) Fit covers on the protruding ends of steel reinforcement. Where this is not possible, mark them with signage; e) Maintain order and cleanliness during formwork operations; f) Prohibit workers from remaining in the area during the hoisting of planks, props and formwork reinforcement; g) Remove or clinch, as applicable, nails or points present in the timber used. Nails that have been removed or are loose shall be collected in a specific location for subsequent disposal; h) Carry out stripping of formwork using metal bars, positioning oneself on the side from which the timber cannot come loose, and i) Sort the formwork elements removed for reuse or disposal.
16.8 For concrete handling and placement, the following safety measures shall be adopted: a) Place wheel stops at the edges for materials-transport trucks, in the case of pours carried out in trenches, foundations and excavations; b) Mark the maximum filling level of the buckets so as not to exceed the permissible load; c) Avoid striking the formwork while emptying the buckets; d) Support the pump pipework on properly braced trestles during concrete pouring by pumping; e) Have the concrete-pour hose supported by at least two operatives; f) Provide a run of planks on which the hose operatives can stand, before the pour begins; g) Carry out the pouring of columns, vertical elements and formwork copings from scaffolding; h) Prepare the pipework, greasing it and pumping the priming mortar, to prevent blockages and plugs from forming, before starting to pump the concrete; i) Check that the formwork is firm and stable before pouring the concrete, and j) Carry out the pouring of concrete, distributing it evenly inside the formwork in regular batches.
16.9 To carry out slab tile laying, the following safety conditions shall be met: a) Stack the material near the work area, clearing the location where the tile-laying tasks will be carried out; b) Delimit the lower part of the area where the tile laying is carried out; c) Handle the materials for tile laying in accordance with the provisions of NOM-006-STPS-2000, or those replacing it; d) Prohibit materials from being thrown down for use at the work site; e) Observe the minimum safety distance, where tile-laying work is carried out near overhead electric power distribution lines, in accordance with Table 7 of this Standard; f) Fit a wooden hoarding and signage where tile-laying work is carried out at less than 3 m from live lines, and g) Prevent access by persons not taking part in these activities.
16.10 For the performance of sandblasting cleaning work, the following safety measures shall be observed: a) Keep an up-to-date list of the personnel who handle and use the sandblasting cleaning equipment; b) Before use, inspect and test the compressed-air equipment (compressor), the safety devices (valves, gauges, relief vents), their connections, and the safe and operational condition of the hose; c) Protect the work area and clean it of the material and other particles removed, and d) Check that, during the application of the sand blast: 1) The specific personal protective equipment is used; 2) The breathable air line for the worker is fitted with filtering devices to retain particles down to 5 microns, moisture and oil mist; 3) The dispersion of dust is prevented; 4) The area is kept delimited, signposted and restricted; 5) The safety data sheets (SDS) for the substances used for cleaning are available; 6) The shot-blasting equipment operator, and where applicable an assistant, are positioned in the application area; 7) The air line for the sand blast is connected independently of the breathable air line; 8) The air flow is cut off by means of the control valve when cleaning stops, and 9) The work clothing and/or the machine are cleaned without using compressed air.
16.11 For the performance of painting, varnishing or coating work using solvent-based products, the following safety measures shall be observed: a) Keep the work area clean and tidy; b) Inform workers of the instructions set out in the safety data sheets (SDS) for the paints, solvents and substances they use; c) Label the containers of varnishes, solvents, paints and other flammable liquids and gases used, in accordance with the provisions of NOM-018-STPS-2000, or those replacing it; d) Prevent solvent-based paints and varnish from being stored in damaged containers; e) Keep the containers of varnishes, solvents, paints and other flammable liquids and gases used closed and away from ignition sources such as flames, sparks or cutting work; f) Mix solvents with paints or varnishes only in the quantities required for the day's work; g) Place paint or varnish residues, and rags or waste soaked with solvents, in closed containers, to prevent the formation of flammable atmospheres; h) Delimit and signpost the work area in accordance with the provisions of NOM-026-STPS-2008, or those replacing it; i) Carry out dust-cleaning activities on walls, scraping and sanding, under air-current ventilation; j) Keep ventilated the area or installation where painting, varnishing or solvent-based coating activities are carried out; k) Use respiratory protection in places with the highest concentration of vapours; l) Have an ABC-type fire extinguisher of at least 6 kg at the location where paint or solvent-requiring mixtures are prepared; m) Prohibit smoking or eating in places where painting is carried out with mixtures containing organic or toxic solvents; n) Have all workers who come into contact with organic or toxic solvents wash their hands and face when they stop or finish the activity; o) Prohibit testing of pipework, boiler or rail installations while paint is being applied to them; p) Prohibit the use of solvents to clean the hands and skin of workers exposed to paints containing organic or toxic solvents; q) Use common water-based cleaners, to prevent the absorption of harmful substances through the skin, and r) Periodically clean the filters and the excess paint accumulated on them.
16.12 For the performance of spray-gun painting, varnishing or solvent-based coating work, the following additional safety measures shall be observed: a) Examine all connections to ensure they are correctly tightened before use; b) Check that the hoses are in good condition before opening the valve for operation; c) Hold the nozzle firmly when opening and closing the air supply; d) Prevent spills of solvents and paints, to prevent the formation of flammable atmospheres; e) Use hearing protection, and f) Close the pressure-supply valves on completion of the work.
16.13 For glazing installation, the following safety measures shall be observed: a) Delimit, signpost and prohibit passage in ground-level areas during installation; b) Keep the work area free of obstacles and clear; c) Store glass panes on timber and/or non-slip material; d) Store, transport and place glass panes always in a vertical position; e) Mark glass panes with paint or adhesive tape so that their presence is noticed during moving and installation; f) Handle glass sheets with safety suction cups; g) Suspend the activity in the event of strong winds; h) Prohibit other workers from remaining or working on the vertical plane of the glazing installation area; i) Keep work areas free of glass fragments; j) Use scaffolding for glazing installation at height, and k) Delimit the ground-level zone where glass is placed on balconies and open spaces at different levels.
16.14 For the installation of electrical networks, the following safety measures shall be adopted: a) Route cables crossing site roads underground by means of conduits; b) Inform the site personnel about the performance of functional tests on the electrical installation; c) Fit moisture- and dust-proof outdoor sockets, and d) Use portable wooden or fibreglass ladders to carry out electrical network installation work.
17. Machinery and equipment
17.1 Those in charge of construction sites shall have an up-to-date list of the machinery and equipment used, indicating at least, for each item: a) The asset or identification number; b) The general description of its use; c) The operating risks and the safety conditions to be adopted to eliminate, reduce or control them; d) The assigned work area, and e) The type of fuel or energy used.
17.2 For the machinery and equipment used on construction sites, a maintenance programme shall be in place, considering at least: a) The asset or identification number; b) The scheduled dates for carrying out maintenance, and c) The maintenance routines, including the checking of safety devices. The document recording the results of the routines shall be signed by the person in charge of the activity.
17.3 To carry out maintenance activities on the machinery and equipment used on construction sites, safety procedures shall be in place, comprising at least: a) The equipment, tools and substances to be used; b) The safety measures to be adopted in the area where maintenance is carried out; c) The personal protective equipment to be worn by the worker carrying out the maintenance; d) The safety measures to be applied to the equipment or machinery during maintenance, such as power isolation, and the fitting of locks and safety tags, and e) The authorisations the worker shall obtain before carrying out the maintenance work.
17.4 Safety conditions for the use of machinery and equipment.
17.4.1 For the operation of machinery and equipment used on construction sites, at least the safety conditions established in NOM-006-STPS-2000, or those replacing it, shall be observed, together with the following: a) Cordon off the surrounding operating radius where activities are carried out with machinery and equipment; b) Check that the machinery has its guards for moving parts fitted before operating it; c) Check that the electrical and mechanical systems present no risk elements before starting operation; d) Check, at the start of the work shift, as applicable, that the tyres show no bulges, cracks, embedded objects or deformation, and that they are at the correct pressure; e) Check that the platforms of the machinery and equipment are free of grease and oil to prevent falls; f) Get on and off the machinery and equipment using the access steps; g) Always wear the seat belt while driving the machinery and equipment; h) Fit signage and use the assistance of flag persons to control the movement of people and vehicles; i) Drive the machinery and equipment at the permitted speed indicated in the traffic zone; j) Bring the vehicle to a complete stop before crossing streets and other traffic routes; k) Move the machinery and equipment keeping the load-bearing elements - forks, bucket, boom, ripper, blade or drag bucket, among others - unlifted or in the operating position; l) Keep the machinery and equipment at the safety distance referred to in clause 11.2, item o), of this Standard, as well as at a distance of at least 2 m from pipework, tanks and equipment containing hazardous fluids; m) Avoid overloading the machinery and equipment, even over short distances; n) Avoid driving the machinery and equipment on steep gradients exceeding the inclinations permitted for which they were designed; o) Prohibit refuelling with the engine running; p) Prevent the machinery and equipment from being used as a means of transport; q) Suspend manoeuvres in the event of rain; r) Park the machinery and equipment on level ground at the end of the work and, where parked on a slope, place chocks alternately on the tyres; s) Apply the parking brake, remove the key to prevent unauthorised starting or movement, and place the operating implements on the ground when leaving the machinery and equipment, and t) Have the employer or the person in charge of the construction site grant written authorisation to the workers who carry out activities with machinery and equipment.
17.4.2 For the operation of air compressors, the following safety measures shall be observed: a) Check that the hoses are single-piece, without joints; b) Check that the hoses show no cracks, joints, cuts or kinks; c) Check that the hose connection mechanisms are secure; d) Keep the pressure hoses protected with guards at pedestrian and vehicle crossings on the site roads; e) Prevent the pressure hose from being used to clean material residue from clothing, and f) Check that the hoses are fully extended when starting the compressor.
17.4.3 For the operation of electric power generators, the following safety measures shall be observed: a) Check that the main output switch is disconnected before starting the electric power generator, by means of the tag, lock and test system; b) Connect the generator's outlet to an electrical panel, in such a way that a properly protected distribution tree is available for supplying several work fronts; c) Fit the lighting generator with a 300 mA residual-current device; d) Install earthing systems for both the neutral of the electric generator and the outlet; e) Secure the earthing system against connection faults by using circuit breakers; f) Restrict access to authorised personnel only to the generator area and to its connections at electrical panels operating at 440 volts or more; g) Fit signage on generators and electrical panels indicating the equipment capacity and the currents available at each outlet; h) Prevent metal objects such as rings, chains, watches and earrings from being worn in the generator area, and i) Prohibit the electric power generator from being located in basements, enclosed or poorly ventilated places, and/or in damp areas.
17.4.4 For the operation of internal combustion engines, the following safety measures shall be observed: a) Have a space for refilling diesel and oil, fitted with equipment to collect any spillage; b) Keep all hose joints free of oil and diesel, and c) Earth the machinery when refuelling.
17.4.5 For the operation of cranes, the following safety measures shall be observed: a) Prepare the ground using mats, steel plates, timber matting, or structural or concrete mats to level and stabilise the crane; b) Keep the outrigger jacks extended to fully unload the wheels and rest them on chocks; c) Observe the minimum safety distance, where the crane is located near overhead electric power distribution lines, in accordance with Table 7 of this Standard; d) Prevent personnel from being transported in load containers, baskets, hooks, cables and other devices not designed for that purpose; e) Fit the hoist motors of mobile cranes with holding brake systems, electrically released and spring-applied; f) Secure the support outriggers when using a crane with a telescopic boom; g) Secure the hooks to prevent the cable or sling from slipping or coming out; h) Use a signal code for all personnel involved in the manoeuvre; i) Prohibit the crane from being used beyond its design capacity, in accordance with the manufacturer's tables for the manoeuvre parameters; j) Prevent the crane from moving until the assistant is positioned in a location that allows maximum visibility of the crane's paths of travel and can direct its operation; k) Prevent the load from being moved over people or the cab; l) Raise the load 10 to 15 cm and check the balance before the moving manoeuvre; m) Move the load using at least two slings distributed at the working angles, so that there is no shifting; n) Position the slings at a working angle of 45º to 60º on each of the lines supporting the load; o) Prevent personnel from remaining behind the crane's counterweight, within the slewing radius, or under the load to be lifted or moved; p) Display the crane's maximum load capacity in a visible place, and q) Provide artificial lighting for night work in the manoeuvring area.
18. Use of tools
18.1 In the use of hand tools, the following safety measures shall be adopted: a) Have instructions on their use, inspection, maintenance and safekeeping; b) Instruct workers on the handling, maintenance and risk prevention of hand tools, taking into account their limitations and possible failures; c) Use personal protective equipment appropriate to the type of work being carried out or the tool being used, always observing the safety warning labels printed on the equipment; d) Check that the handles of hand tools are hard and of a suitable size. They shall not be slippery; e) Check that the joint between the handles and the rest of the hand tool is firm, to prevent breakage from creating a hazard for the worker; f) Check that hand tools have the guards necessary to prevent direct contact with their moving parts; g) Prevent the operation of hand tools without their protective guards, where these were fitted by design; h) Check that hand tools are of the size and characteristics suited to the use; i) Remove burrs and filaments that could come off the accessories when using hand tools; j) Avoid working with hand tools that are in poor condition or damaged; k) Carry out work with hand tools, preferably, on level surfaces; l) Place hand tools in suspended locations and, if left on the ground, protect them or signpost them appropriately; m) Check that the workpiece is firmly secured and well positioned; n) Always keep in place the parts forming the protective cover of hand tools; o) Avoid leaving hand tools in walkways, stairways and pedestrian traffic areas; p) Signpost and delimit work areas where the use of hand tools poses a risk to other workers; q) Make test cuts where hand tools are used in places with electrical installations, and r) Establish a written programme for the inspection and recording of hand-tool maintenance.
18.2 In the use of electric tools, the following safety measures shall be adopted: a) Prevent the modification of the power cable of hand-held electric tools, in accordance with the manufacturer's design; b) Prevent the equipment from being used if the cable is scuffed, exposing the copper wires, or has joints made with insulating tape; c) Use double-insulated extension leads matching the tool's voltage, fitted with an earth-fault device and free of splices or tears; d) Remove flammable and combustible materials when carrying out work with electric tools; e) Always keep in place the parts forming the protective cover; f) Disconnect hand-held electric tools when stopping or finishing the activity, without pulling on the cable, and g) Join installation cables using mechanical connectors.
18.3 In the use of cutting tools, the following safety measures shall be adopted: a) Select the tool according to the material to be cut; b) Check that the cutting elements show no excessive wear, cracks or fissures, and replace them immediately if they do; c) Avoid working in areas with poor access, and avoid forcing the position of the tool's cutting element; d) Carry out the ring test on the cutting disc to check that it is in safe and operational condition; e) Check, when working with cutting tools, that there are no pipes carrying gas or hazardous substances; f) Use cutting elements in accordance with the tool's rated speed; g) Control the generation of sparks during and at the end of work with cutting tools; h) Periodically wet the area of concrete to be cut; i) Use a dust extractor or carry out the work in open areas; j) Check that the securing elements of the cutting tools are secure, and k) Replace cutting elements when they reach the end of their service life as established by the manufacturer.
18.4 In the use of pneumatic tools, the following safety measures shall be adopted: a) Check that the supply network is compressed air and not another gas, where the pneumatic tool is connected to a general network; b) Prohibit the use of gaseous oxygen as a power source for the pneumatic tool. Use only filtered, lubricated and compressed air; c) Check that taps and valves on the pneumatic-tool supply network are working properly; d) Check the safe and operational condition of the pneumatic tool, as well as of the connecting hose and its joints; e) Check that the length of the hose is sufficient and suitable for the work to be carried out; f) Ensure the correct coupling of the pneumatic tool to the hose; g) Keep the compressed-air pressure constant, check the compressor's oil level, and prevent water accumulation; h) Prevent the maximum pressure recommended by the manufacturer from being exceeded, and check that the line pressure is compatible with the elements or tool to be used; i) Prohibit the trigger of pneumatic tools from being squeezed while the tool is being loaded; j) Prevent pneumatic tools from being carried by the hose or squeezed while being moved; k) Check that the compressed-air supply hose is kept as far away as possible from the work area; l) Periodically check the safe and operational condition of the hoses and connections, discarding those that are broken or deteriorated. Do not make joints in the hoses; m) Periodically replenish the oil in the lubricators, using that specified by the equipment manufacturers; n) Prohibit the use of petrol or other flammable liquid to clean the pneumatic tool; o) Disconnect the pneumatic tool from the air hose before clearing blockages, and carry out servicing and adjustments only while it is not in use; p) Avoid the use of control valves that allow air to remain in the pneumatic tool; q) Prevent the hoses of pneumatic tools from resting on the ground and, where applicable, from being placed in areas where they could be damaged by the passage of moving elements; r) Protect hoses with planks or in small trenches where they have to cross site machinery; s) Take periodic breaks or alternate tasks, and t) Prohibit workers from directing air jets at people or using them to clean clothing.
18.5 In the use of tools that run on liquid fuel, the following safety measures shall be adopted: a) Prevent workers from being near a fire, smoking, or using them while refuelling; b) Prevent spills during filling and clean them up immediately if they occur; c) Prohibit the machine from being started in the same place where it is refuelled, and d) Check that there are no leaks at the joints, to prevent risks of fire or explosion.
19. Emergency response plan
19.1 The emergency response plan for construction sites classified as small shall contain the following: a) A list of the actions for emergency response, including those relating to first aid; b) The person responsible for implementing the actions; c) The resources for assisting personnel, including the first-aid kit, and d) The telephone numbers for requesting assistance from the fire brigade, hospitals, police and rescue services.
19.2 The emergency response plan for construction sites classified as medium-sized shall contain, in addition to the provisions of clause 19.1, the following: a) The internal and external communication procedure in the event of an emergency, together with a directory for locating the person in charge of the construction site, and b) Instructions for: 1) Evacuation; 2) Fire-fighting, and 3) First aid.
19.3 The emergency response plan for the various phases of construction sites classified as large shall contain the following: a) The scope of the plan; b) The person responsible for implementing the plan; c) The human and material resources for putting it in place; d) The training of workers in relation to the content of the plan; e) The frequency and type of emergency drills to be carried out; f) The personal protective equipment required for emergency response; g) The evaluation and feedback of the emergency response plan; h) The description of the facilities, the activities to be carried out and the surroundings; i) The analysis of internal and external risks, including natural phenomena; j) The inventory of the material resources available to deal with emergency situations; k) The operating instructions for the control and management of the potential emergencies resulting from the risks detected, together with those for the personnel who activate the plan; l) The identification of evacuation routes, assembly points and/or safety zones; m) The procedures for: 1) Raising the alarm, in the event of an emergency; 2) Internal and external communication in the event of an emergency, together with the directory for locating, at any time of day, those responsible for the preventive occupational safety and health services and for the construction site; the emergency assistance services (fire brigade, hospitals, police and rescue), as well as, where applicable, the directory of the information centres for handling chemical substances in emergencies; 3) The shutdown of machinery and equipment; 4) The suspension of activities; 5) The evacuation of workers and visitors; 6) First aid; 7) The elimination of risks after the emergency; 8) The assessment of damage, and 9) The return to normal operating activities, and n) The setting-up of the emergency response teams, with the assignment of posts and responsibilities, specifying the personnel trained and instructed for: 1) Emergency and disaster response; 2) Evacuation; 3) First aid, and 4) Fire-fighting.
20. Training
20.1 Training for workers on large construction sites shall be provided in accordance with training programmes prepared for that purpose, which shall relate, as applicable, to each phase of the site; to the content of the construction site safety and health system, as well as to the construction site safety and health programme and the safety instructions applicable to the activities carried out by the workers.
20.2 The training provided to workers on large construction sites shall include, at least, the following topics: a) Information on the occupational risks relating to the activity they will carry out; b) The safe way to handle or use machinery, equipment, tools, materials and substances; c) The safety measures to be adopted to carry out the activities or work, and d) The use, maintenance, upkeep, storage and replacement of personal protective equipment, in accordance with the provisions of Chapter 7 of NOM-017-STPS-2008, or those replacing it.
20.3 The information provided to workers who carry out hazardous work on medium-sized construction sites shall be provided before the start of such activities.
20.4 The occupational safety and health talks provided to workers on medium-sized construction sites shall relate to the risk prevention, protection and control measures and to the safety instructions applicable to the activities carried out by the workers.
21. Recording and investigation of occupational accidents
21.1 Construction sites shall have a record of occupational accidents, which shall contain, at least, the following: a) The type of accident that occurred; b) The frequency and severity indicators for monitoring its incidence; c) The pattern of occupational accidents, according to the activities and phases of the site, and d) The follow-up on the safety measures adopted after an accident, based on the results of the investigation.
21.2 Where an occupational accident occurs on a construction site, an investigation shall be carried out comprising at least the following: a) The identification of the general details of the injured person; b) The causes of the accident, including the hazardous or unsafe conditions and/or unsafe acts that caused the accident, illness or material damage; c) The consequences of the accident, specifying the part of the body injured, and the type of injury and/or material damage caused; d) The sequential description of the accident and of the mechanism of exposure; e) The assessment of the accident, with the probability of occurrence and severity of the harm; f) The activities or measures that should have been in place to prevent the accident; g) The follow-up on the accident and the safety measures implemented; h) The history of previous occupational illnesses and injuries suffered by the injured worker; i) The outcome of the investigation, and j) The proposed safety measures to be adopted, whether in the near or immediate term, based on the results of the investigation, to prevent the accident from recurring.
22. Verification units
22.1 The employer may engage an accredited and approved verification unit, under the Federal Act on Metrology and Standardisation and its Regulations, to verify the degree of compliance with this Standard.
22.2 Verification units assessing conformity with this Standard shall apply the compliance criteria established in the conformity assessment procedure in Chapter 23 of this Standard.
22.3 The employer may consult the current directory of verification units accredited and approved by the Ministry of Labour and Social Welfare at the following website: www.stps.gob.mx.
22.4 Accredited and approved verification units assessing compliance with this Standard shall issue a report, which shall contain: a) Workplace details: 1) The name, designation or business name of the person in charge of the construction site; 2) The address of the workplace, and 3) The name and signature of the legal representative, and b) Verification unit details: 1) The name, designation or business name; 2) The registration number granted by the accreditation body; 3) The approval number granted by the Ministry of Labour and Social Welfare; 4) The date on which accreditation and approval were granted; 5) The outcome of the verification; 6) The name and signature of the person responsible for issuing the report; 7) The place and date of signature of the report, and 8) The validity period of the report.
22.5 The validity period of the verification report, where it is favourable, shall be two years, or for the duration of the construction site where that period is shorter.
23. Conformity assessment procedure
23.1 This conformity assessment procedure applies both to the inspection visits carried out by the labour authority and to the verification visits carried out by verification units.
23.2 The current verification report shall be available to the labour authority upon request.
23.3 The aspects to be verified during the conformity assessment of this Standard shall be checked, as applicable, by means of physical verification, documentary review, records or interviews, in accordance with the following: Type of
Provision Acceptance criterion Remarks
evaluation
5.1 and 7 Documentary. The employer complies when it presents documentary evidence that it carried out the classification of the size of the construction site, and that the characteristics of Table 1 of this Standard were taken into account in that classification.
5.2 Documentary. The employer complies when it presents documentary evidence Applies to that it has: small sites. 3 The description of the activities to be carried out;
3 The risks faced by
workers, and 3 The list of safety measures to be adopted before and during their performance.
5.3 a), 8.1 and The employer complies when: Applies to sites
8.3 medium-sized.
determined on the basis 3 The activities to be carried out or trades that of the records will take part; kept by the 3 The conditions of the facilities; company itself, 3 The safety and operating conditions of the in accordance with tools, equipment and NOM-021-STPS- machinery to be used; 1993, or those 3 The identification of the hazards present; replacing it. 3 The analysis of workers' exposure to the hazards; 3 The determination of the risks and their possible impact, based on the hazards present, in accordance with the hierarchy established in clause 8.3 of this Standard; 3 The prevention, protection and control measures applicable to the risks detected, and 3 The signature of the person in charge of the site; ¾ Presents documentary evidence that it carried out the hierarchy of risk impact; ¾ The hierarchy of risk impact shall comprise: 3 The category of frequency of occurrence of the risks, in accordance with the provisions of Table 2 of this Standard; 3 The severity of the harm the risk may cause, in accordance with the provisions of Table 3 of this Standard, and 3 The hierarchy of risk impact, in accordance with the provisions of Table 4 of this Standard, as serious, high, medium, low and minimal, and ¾ Presents documentary evidence that it addresses the risks in the following sequence: serious, high, medium, low and, finally, minimal. Type of
Provision Acceptance criterion Remarks
evaluation
Documentary ¾ Presents documentary evidence that it has the
potential risk analysis; The frequency of
occurrence is
¾ The risk analysis considers the following:5.3 b), 8.2 and The employer complies when: Applies to sites
8.3 Documentary. ¾ Presents documentary evidence that it has the large sites. potential risk analysis; the frequency of
NOM-021-STPS- 3 The safety and operating conditions of the 1993, or those tools, equipment and replacing it. machinery to be used; 3 The safety instructions; 3 The risk factors present in the work activities; 3 The possible causes of events leading to accidents, linked to the hazards previously identified; 3 The analysis of workers' exposure to the hazards of the activities or phases of the site; 3 The determination of the risks and their possible impact, based on the hazards present, in accordance with the hierarchy established in clause 8.3 of this Standard; 3 The prevention, protection and control measures applicable to the risks detected, and 3 The signature of the employer, of the person in charge of the site, or of the person in charge of the preventive occupational safety and health services; ¾ Presents documentary evidence that it carried out the hierarchy of risk impact; ¾ The hierarchy of risk impact comprises: 3 The category of frequency of occurrence of the risks, in accordance with the provisions of Table 2 of this Standard; 3 The severity of the harm the risk may cause, in accordance with the provisions of Table 3 of this Standard, and 3 The hierarchy of risk impact, in accordance with the provisions of Table 4 of this Standard, as serious, high, medium, low and minimal, and ¾ Presents documentary evidence that it addresses the risks in the following sequence: serious, high, medium, low and, finally, minimal.
| ¾ The analysis of potential risks considers the | occurrence is |
| following: | determined on the basis |
| 3 The activities or work to be carried out at each | of the records |
| phase of the construction site, on the basis of the | kept by the company itself, |
| site project; | in accordance with the |
| 3 The conditions of the facilities; | provisions of |
5.4 a), 9.1 and The employer complies when: Applies to sites
9.2 Documentary. ¾ Presents documentary evidence that it has a medium-sized sites. construction site safety and health system established before starting the activities, and ¾ The construction site safety and health system comprises the following: 3 The occupational safety and health policy; 3 The classification of the site; 3 The determination of the risks associated with the activities; Type of
Provision Acceptance criterion Remarks
evaluation 3 The construction site safety and health programme containing the prevention, protection and control measures for those risks; 3 The authorisation to carry out hazardous work; 3 The signature of the employer and/or of the person in charge of the construction site, and/or of the person in charge of the preventive occupational safety and health services; 3 The information on the risk prevention, protection and control measures; 3 The list of safety measures and instructions for the activities to be carried out on the site; 3 Programmes for: o Training in occupational safety and health matters; o The selection, use and maintenance of basic and, where applicable, specific personal protective equipment; o The review and preventive maintenance of
machinery, equipment, tools and
safety devices, and o The supervision and monitoring of safety on the site; 3 Safety instructions for the access and control of personnel on the site, applicable to workers, subcontractors, suppliers and visitors, which shall at least include working hours, the definition of entry to and exit from the work areas, the personal protective equipment to be used, and evacuation routes; 3 The first-aid manual, and 3 The emergency response plan, in accordance with the provisions of Chapter 19 of this Standard.
5.4 b), 9.1 and The employer complies when: Applies to sites
9.3 Documentary. ¾ Presents documentary evidence that it has a large sites. construction site safety and health system established before starting the activities, and ¾ The construction site safety and health system comprises the following: 3 The occupational safety and health policy; 3 The classification of the site; 3 The determination of the risks associated with the activities; 3 The construction site safety and health programme containing the prevention, protection and control measures for those risks; 3 The authorisation to carry out hazardous work; 3 The signature of the employer and/or of the person in charge of the construction site, and/or of the person in charge of the preventive occupational safety and health services; Type of
Provision Acceptance criterion Remarks
evaluation 3 The description of the site to be carried out, addressing: o The total construction area; o Technical data or the executive project: architectural and structural drawings, of plumbing, electrical and special installations, together with their corresponding technical calculation reports and schedule of items and/or location sketches, and o The location of the site and its surroundings; 3 The description of temporary facilities: offices, warehouses, workshops, canteens, medical service, storage yards, equipment-washing areas, toilets, access points, perimeter protection, lighting, earthing connections and roadways, as applicable; 3 The organisation chart of the site personnel and the responsibilities of the different levels, in occupational safety and health matters; 3 The analysis of the potential risk of each activity, including the detection, evaluation and hierarchy of the hazards and risks associated with the main activities to be carried out during the performance of the work, in accordance with the construction site safety and health programme; 3 Programmes for: o Training in occupational safety and health matters; o The selection, use and maintenance of basic and, where applicable, specific personal protective equipment; o The review and preventive maintenance of
machinery, equipment, tools and
safety devices, and o The supervision and monitoring of safety on the site by phases; 3 Safety instructions for the access and control of personnel on the site, applicable to workers, subcontractors, suppliers and visitors, which shall at least include working hours, the definition of entry to and exit from the work areas, the personal protective equipment to be used, and evacuation routes; 3 The first-aid manual, and 3 The emergency response plan, in accordance with the provisions of Chapter 19 of this Standard.
5.5 The employer complies when: Applies to
Documentary. ¾ Presents documentary evidence that it has and monitors medium-sized and
a programme for the review and large sites. preventive maintenance of the equipment and/or machinery used, and ¾ The programme contains at least the activity to be carried out, the dates of performance, and the person responsible for its execution. Type of
Provision Acceptance criterion Remarks
evaluation
5.6 The employer complies when: Applies to
Documentary. ¾ Presents documentary evidence that it has medium-sized and
safety procedures for the review and large sites. maintenance of the tools and equipment used by workers; ¾ The procedures cover at least the activity to be carried out, the dates of performance and the person responsible for its execution, and ¾ Presents documentary evidence that it has safety procedures for the installation and management of temporary and permanent electrical installations.
5.7 The employer complies when: Applies to
Documentary. ¾ Presents documentary evidence that it has medium-sized and safety instructions for carrying out: large sites.
3 Backfilling and compaction work; 3 Formwork fabrication and handling work; 3 Concrete handling and placement work; 3 Where applicable, for carrying out two or more of these activities simultaneously, and 3 Hazardous work.
Documentary ¾ Presents documentary evidence that it has medium-sized and
safety instructions for carrying out: large sites.5.8 and 10 The employer complies when: Physical. ¾ Demonstrates that it provides workers with the basic personal protective equipment corresponding to their job and, where applicable, the specific equipment corresponding to them, on account of carrying out hazardous work, on the basis of the provisions of Table 5 of this Standard, or of the risk analysis referred to in NOM-017-STPS-2008, or those replacing it; ¾ Demonstrates that the same personal protective equipment is provided to workers in the different categories of the trade corresponding to the job; ¾ Demonstrates that the personal protective equipment provided to workers and visitors bears, where applicable, the certification issued by a certification body accredited and approved under the Federal Act on Metrology and Standardisation, or the manufacturer's guarantee that it protects against the risks for which it was manufactured, and
Documentary. ¾ Presents documentary evidence that the
basic personal protective equipment and, where applicable, the specific equipment provided to workers is that which corresponds to them, on the basis of the provisions of Table 5 of this Standard or of the risk analysis referred to in NOM-017-STPS-2008, or those replacing it.
5.9 Documentary. The employer complies when it presents documentary evidence that it has procedures for the use, inspection, replacement, cleaning, limitations, maintenance, safekeeping and final disposal of personal protective equipment, based on the manufacturer's information and in accordance with NOM-017-STPS-2008, or those replacing it.
5.10 and 10.2 Physical. The employer complies when it demonstrates that it is supervised that Applies to medium-sized workers wear the basic personal protective equipment and, where applicable, the specific and large sites. equipment. In the case of medium-sized and large enterprises, visitors wear at least a safety helmet and, in addition, other types of equipment, based on the risk to which they are exposed. Type of
Provision Acceptance criterion Remarks
evaluation
5.11 and 11 The employer complies when: Applies to sites
excavations, it considers, in addition to the provisions of small sites are exempted from clauses 8.1 or 8.2 of this Standard, as demonstrating
documentary evidence or of the 3 The presence of services near the records compiled. excavation: live lines, pipes, ducts and other infrastructure networks; 3 Weather changes; 3 The cutting depth; 3 The method for stabilising the excavation slopes, where applicable; 3 The equipment, machinery and tools to be used; 3 The type and quantity of explosives to be used, where applicable, and
3 The process of removal, loading, haulage and
slope stability;
Physical. ¾ Demonstrates that it adopts the safety measures
following in excavation work: 3 Inspects the excavation site to detect potential faults, cracks or collapses: o At the start of each shift and on completion of the work, to detect changes in the ground; o After heavy rain; o After the passage of heavy machinery or intense vehicle traffic, and o On conclusion of any event that could increase the risk; 3 Inspects, at the start and end of each shift, the systems used to stabilise the walls of trenches; 3 Prohibits workers from remaining inside the trench while the excavation machinery is in operation; 3 Removes trees, bushes and shrubs that hinder the stability of the ground cuts to be made, where the relevant authorisations are held; 3 Secures the supports or anchors of electrical power poles or, where applicable, requests their relocation from the competent authority; 3 Reinforces the walls of the excavation with props, linings, mesh, platforms, formwork, crosspieces or shoring (sheet piling), where there is a risk of collapse. In excavations for piles, prohibits the entry of workers where the walls of the excavation lack due protection; Type of
Provision Acceptance criterion Remarks
evaluation 3 Carries out excavations at work faces with stable slopes, the inclination of which is in accordance with the type of soil and/or Table 6 of this Standard; 3 Stabilises the walls of the trench with elements extending 20 cm above the ground surface, where its depth is greater than 1.50 m; 3 Installs support systems to ensure the stability of adjoining buildings, boundary walls or other structures adjacent to the excavation; 3 Provides, in trench excavations 1.20 m or more in depth, a ladder or ramp for workers to enter and exit. The ladder projects 90 cm above the highest part of the trench and is placed at a maximum horizontal distance of 7 m from the work site; 3 Keeps machinery and equipment, in particular those fitted with a boom, lifting equipment and similar items, at a minimum safety distance when located near overhead electric power distribution lines, in accordance with Table 7 of this Standard; 3 Provides separate access routes for circulation, one for workers and another for machinery and lorries. Where this is not possible, delimits the access with physical barriers; 3 Provides walkways or bridges at the edge of the excavation; 3 Signposts and delimits the perimeter of excavations with hazard tape or protective mesh, where the depth is less than 1.5 m, and with rigid barriers 90 cm high, for those with a depth greater than 1.5 m; 3 Limits access to the trench to a safety distance measured from the vertical plane of the trench wall, determined in accordance with the outcome of a study that addresses, at least, the type of soil or rock; the width and depth of the trench; the maximum loads of the machinery, vehicles or stockpiled materials; and the shoring in the trench, where applicable; 3 Provides lighting appropriate to the work shift; 3 Uses portable equipment supplied at 24 volts, where the use of electrical wiring poses a risk to the installation of artificial lighting; 3 Avoids stockpiling materials or soil less than 2 m from the edge of the excavation, so as not to impose overloads on the ground; 3 Keeps the excavation open for the shortest possible time; 3 Notifies the supervisor of the presence of electrical wiring and marks its location; Type of
Provision Acceptance criterion Remarks
evaluation 3 Carries out air-quality sampling where an excavation becomes a confined space and hazardous atmospheres are present, such as the presence of gases or lack of oxygen, among others, whatever its depth, and, where applicable, installs a ventilation system; 3 Suspends excavation work where there is an accumulation or rise in the water level and removes it immediately to prevent the stability of the slopes from being altered, using the equipment available for that purpose, and 3 Has safety measures in place for the use of explosives, and ensures that such activities are carried out in accordance with the regulations issued for that purpose by the Ministry of National Defence;
Documentary. ¾ Presents documentary evidence that it selects the
shoring design according to the time it will be used for, the resistance of the soil and the materials to be used, and
Physical. ¾ Demonstrates that, for trench shoring, it adopts
the following safety measures: 3 Avoids simultaneous shoring work at different levels on the same vertical plane; 3 Discards props that are open or splintered; 3 Marks or places barriers and warning signs in high-voltage areas; 3 Makes electrical connections using weatherproof sealed mechanisms, and 3 Prohibits workers from descending into or climbing out of the trench using the props.
Documentary ¾ Presents documentary evidence that it has the small,
potential risk analysis for excavation work, medium-sized and
where applicable; large sites.
¾ The potential risk analysis for excavation work Small sites are exempted from considers, as applicable, the following: demonstrating compliance by
3 The soil mechanics study, addressing the type those measures
of soil to be excavated, its physical composition and that involve a
mechanical properties; documentary or5.11 and 12 The employer complies when: Applies to
evaluation type 3 The risks of the materials and/or substances to be documentary or of the used (toxicity, flammability, reactivity or records compiled. specific risks); 3 The list of possible hazardous conditions and risks; 3 The estimated duration of the activities to be carried out, and 3 The effects of oxygen concentration in confined spaces, in accordance with the provisions of Table 8 of this Standard; Documentary. ¾ Presents documentary evidence that it has: 3 The safety procedures for the activities to be carried out and for the equipment and tools to be used; 3 The sampling procedures for detecting hazardous atmospheres or oxygen deficiency; 3 A specific work plan, in case adverse atmospheric conditions persist in that space, and 3 The rescue plan for possible casualties in the confined space, including the rescue equipment for emergencies; Type of
Provision Acceptance criterion Remarks
evaluation
Physical. ¾ Demonstrates that, for carrying out
activities in confined spaces, it has the following safety measures: 3 The signage at the entrance to the confined space; 3 The person in charge of supervising the work is located outside the confined space; 3 The personal protective equipment required. Where the oxygen level inside the confined space is equal to or less than 19.5 per cent, workers are provided with airline equipment or self-contained breathing apparatus; 3 Natural or forced ventilation systems to maintain a respirable atmosphere at all times. It does not use compressed air as a source of ventilation in a confined space; 3 Lighting inside confined spaces in the presence of flammable or explosive materials or substances, on the following basis: o Luminaires with low-voltage safety ratings, up to 24 volts, and o Explosion-proof, heavy-duty lamps; 3 Tools and electrical equipment requiring more than 12 volts to operate are, in explosive atmospheres, fitted with a residual-current earth-fault circuit breaker connected to a physical earth. The switch, the transformer and other circuit elements are located outside the confined space, and 3 The communication mechanisms between the personnel operating inside the confined space and the supervising personnel;
Records. ¾ Presents documentary evidence that it has the
records relating to: 3 The control of personnel entering and leaving the confined space, by means of the corresponding authorisation, which remains at the entrance while the activities are being carried out; 3 The length of time workers remain inside the confined space, where applicable, with variable rest breaks according to the temperature conditions of the working atmosphere, the work regime and the worker's body temperature, and 3 Continuous atmospheric sampling, where work is carried out in confined spaces with flammable, explosive or toxic liquids, or atmospheres with oxygen deficiency;
Documentary. ¾ Presents documentary evidence that the
authorisations for entry into confined spaces contain at least the following information: 3 The place where the activity will be carried out; 3 The date on which the work will be performed; 3 The name and signature of the personnel authorised to enter; 3 The name and signature of the person in charge of the area where the activity will be carried out, and 3 The name and signature of the person granting the authorisation; Type of
Provision Acceptance criterion Remarks
evaluation ¾ Presents documentary evidence that the rescue plan for confined spaces is reviewed with all personnel entering such spaces and with relief personnel; ¾ Presents documentary evidence that the rescue plan for confined spaces contains at least: 3 The description of the different emergencies that could arise; 3 Who to ask for help in an emergency, and how; 3 Instructions on how to assist one or more persons in an emergency, and 3 The procedure for assisting personnel using self-contained breathing apparatus, and
Physical. ¾ Demonstrates that, in the welding and cutting activities
carried out in a confined space, it adopts the following safety measures: 3 Ventilates the inside of the confined space so that no flammable or explosive atmospheres are present; 3 Has a forced air extraction and recirculation system to prevent welding fumes; 3 Has at least one ABC-type fire extinguisher of a capacity matching the materials and type of fire that could occur; 3 Uses the personal protective equipment required for the activity, the job and the place where it will be carried out; 3 Has, where applicable, screens to delimit the areas where welding or cutting activities are carried out; 3 Locates welding machines and cylinders outside the confined space; 3 Checks the cables and connections before they are brought into the confined space; 3 Uses pressure regulators, gauges and flashback-arrestor valves in safe and operational condition; 3 Uses crimped-type connections on hoses, and 3 Checks the hoses and connections before they are brought into the confined space to prevent possible leaks.
Documentary ¾ Presents documentary evidence that it has the small,
risk analysis for work in confined medium-sized and
spaces, where applicable; large sites.
¾ The risk analysis for work in confined spaces Small sites are exempted from
comprises at least the following: demonstrating compliance by
3 The description of the activity to be carried out; documentary evaluation
3 The conditions of the place where the or the records
activity will be carried out; compiled, of those
3 The machinery, tools and equipment to be used; measures that involve a5.11 and 13 The employer complies when: Applies to
protected by compression-resistant crossing supports and fully extended; Type of
Provision Acceptance criterion Remarks
evaluation
3 Keeps flammable and
combustible materials at a minimum distance of 10 m; 3 Prohibits the use of clothing stained with grease, solvents or any other substance liable to catch fire; 3 Prevents work from being carried out where the area is wet, or, failing that, insulates the area on a wooden base; 3 Avoids pulling the cables, even where they become caught or offer resistance to handling; 3 Disconnects the machine on completion of the work, collects the cables and stores them in a dry place, and 3 Removes the materials and leaves the work area clean before, during and after the shift;
Physical. ¾ Demonstrates that, in electric welding
activities, it adopts the following safety measures: 3 Carries out welding activities in accordance with the provisions of NOM-027-STPS-2008, or those replacing it; 3 Has pliers, hooks, tongs or any other means available for handling the materials on which the welding work is performed; 3 Places, where applicable, the parts to be welded on a table or area with a base of insulating or heat-dispersing, fire-resistant material; 3 Checks the insulation of the electrical cables at the start of the shift and discards those showing cracking and direct connections protected with insulating tape; 3 Checks that the electrode holders and connection terminals are insulated and in safe and operational condition; 3 Keeps electric-arc welding machines as far away as possible from the site of the operation and also from furnaces or other heat sources; 3 Controls the generation of sparks during and at the end of welding work, where applicable, by installing screens or fire-retardant blankets; 3 Prevents cables from resting on hot objects, puddles, sharp edges or any other place that could damage the insulation; 3 Monitors the atmosphere with an explosimeter during welding work carried out in enclosed spaces; 3 Cleans welding residues with a wire brush or hammer; 3 Prohibits electrode holders from being placed in water to cool them; 3 Suspends outdoor welding work in the event of rain or where clothing becomes wet from sweat or another liquid; 3 Disconnects the equipment before making voltage changes and does not leave the holder directly on the ground or on structural steelwork, and 3 Fully disconnects the equipment whenever it is removed from the work site, including to move it; Type of
Provision Acceptance criterion Remarks
evaluation
Documentary. ¾ Presents documentary evidence that, for
oxy-acetylene cutting activities, it has procedures for the handling and operation of cylinders, valves, regulators, hoses and their connections, as well as electrical power sources, and
Physical. ¾ Demonstrates that, for
oxy-acetylene cutting activities, it adopts the following measures: 3 Keeps the area clean and tidy during and on completion of the activity; 3 Ensures that flashback-arrestor valves are fitted between the torch handle and the hoses, and between the hose and the regulator, for both the oxygen and the acetylene; 3 Checks that there is no evidence of deformation, cracks or fractures in the cylinders, valves, regulators and hoses; 3 Positions the cutting equipment at least 3 m from the work site; 3 Checks that the cylinders: o Have caps fitted when stored or out of use; o Are stored vertically and secured with a chain; o Are not used to hang the torch, even when it is switched off; o Are moved on a trolley specifically designed for that purpose, firmly secured with a chain to prevent them falling; o Are not heated following flashback or a fire at the tap, and o Are moved for replacement by rotating them on their own base, and not rolled horizontally or dragged; 3 Checks that the regulators: o Have threads or fittings matching those of the valve outlet. Connections that do not match are never forced; o Are fitted with calibrated gauges in safe and operational condition; o Have dials, indicator needles, mica or protective glass, and o Are not interchanged or fitted onto others not designed for the type of cylinder used; 3 Checks that high-pressure oxygen gauges are fitted with safety caps and marked with the word OXYGEN and a green marking, and that acetylene gauges are marked with the word ACETYLENE with a red marking; Type of
Provision Acceptance criterion Remarks
evaluation 3 Checks that the hoses: o Have crimped or pressure connections for joining them to the torch and regulator handles; o Are protected with compression-resistant crossing supports where they cross vehicle or pedestrian traffic routes, and o Do not come into contact with hot surfaces, sharp edges, sharp corners or sparks, and 3 Prohibits, during the activities: o Striking the torch against any structure; o Smoking while handling the torches, and o Using oxygen to clean or blow out parts and pipework or to ventilate a room.
Physical ¾ Demonstrates that, to protect the workers who small,
carry out electric welding work and personnel medium-sized and
passing near where such activities are large sites.
carried out, it adopts the following safety Small sites are exempted from
measures: demonstrating compliance by
3 Checks that the welder's face shield or welding documentary evaluation
goggles have no openings and that the shade lens or the records
against radiation is the one specified; compiled, of those
3 Places screens or shields around the welding measures that involve a
station for the entire duration of the documentary-type evaluation
activity; or of the
3 Checks that the cables do not cross a traffic records that are
route, such as walkways and stairs, and that they are compiled.5.11 and 14 The employer complies when: Applies to
and where this is unavoidable, specific documentary evaluation or the safety measures are adopted for such records compiled. activities; 3 Access by persons unconnected with the work area is prohibited, and 3 The records of inspections of the systems or equipment used for work at height are kept available on the construction site;
Records. ¾ Presents documentary evidence that any damage or defects identified in the systems or equipment used for work at height are recorded and
reported immediately to the person in charge of the site and/or the safety personnel;
Physical. ¾ Demonstrates that, for the use of tower- or
structure-type scaffolding, the following safety measures are adopted: 3 Rigid barriers are fitted on platforms that open inwards or upwards to safeguard access to the scaffold stairways; 3 The work area and the access route around the scaffold are protected against objects or tools falling from the working platform, and 3 The following are prohibited on scaffolding: o The use of electrical cable trays as platforms; o The installation on them of material hoists, unless they are designed or reinforced to bear an additional load; Type of
Provision Acceptance criterion Remarks
evaluation o The use of stepladders, barrels, drums, concrete blocks and other objects as part of their structure, and o The use of roof gutters, drains,
pipe supports, lightning conductors or conductors as elements for
securing them;
Physical. ¾ Demonstrates that, for the use of suspended scaffolding,
the following safety measures are adopted: 3 A documented load test is carried out at ground level before work begins; 3 Mesh is placed around the perimeter of the platform, where materials or tools present a risk of falling; 3 Tie-off points are established on the vertical faces; 3 It is checked that the gap between the front face of the platform and the vertical face being worked on is no greater than 30 cm; 3 It is checked that there are no cables or obstructions that could overload or tilt the scaffold, and 3 The use of planks as walkways between platforms of suspended scaffolding is prohibited;
Physical. ¾ Demonstrates that, for the use of harnesses and lifelines,
the maximum number of workers anchored to the same point is limited according to the strength of that anchor point and the design and construction characteristics established by the manufacturer;
Physical. ¾ Demonstrates that, for the use of aerial lift
platforms, the following safety measures are met: 3 They are operated only by qualified personnel; 3 A tag is placed in a visible place at the access point, attached in such a way as to prevent accidental removal, indicating the condition of use and the date and name of the person who inspected it; 3 There is signage, in accordance with the manufacturer's specifications, indicating: o The maximum weight to be supported; o The operating radii, and o The maximum number of persons it can bear; 3 The stabilisers are extended and the equipment is level before raising the basket; 3 They are free of personnel around them while in operation; 3 They are capable of being operated directly, at any time, by means of dual operating-control systems; 3 The carrier is operated only when the surface of the platform on which it rests is level and firm; 3 The platform is secured to the structure where the platform is accessed from elevated places; 3 Personnel clip on to a fall-protection system before descending from the basket, and 3 Moving the carrier with the arm extended or with personnel inside the platform is prohibited, and Type of
Provision Acceptance criterion Remarks
evaluation
Physical. ¾ Demonstrates that, for the use of portable ladders on
construction sites, the following safety measures are met: 3 It is ensured that both the lower and upper access areas are kept clean and clear of any material; 3 It is checked, before use, that: o They are in safe and operational condition; o The rungs or side rails show no damaged, bent, dented or broken elements, and
o The non-slip feet are not
worn or broken; 3 The carrying of loads while ascending or descending the ladder is prohibited, and 3 They are prevented from being placed above moving mechanisms.
Physical ¾ Demonstrates that work at height is carried out small,
in accordance with the provisions of NOM-009-STPS-2011, medium-sized and
or those replacing it; large sites.
¾ Demonstrates that, in carrying out work at height, Small sites are exempted from
the following safety measures are applied: demonstrating compliance by
3 It is supervised by a person with knowledge documentary evaluation
of fall protection on the construction or the records
site; compiled, of those measures
3 Different workers are prevented from performing that involve a
tasks on the same vertical plane at different heights, documentary-type evaluation| pipe supports, | lightning conductors or |
| conductors, | as elements for |
5.11 and 15 The employer complies when: Applies to
Documentary. ¾ Presents documentary evidence that: small, medium-sized 3 A record is kept of the site access permits for and large sites.
the transport of materials, with the description of Small sites are exempted from the activities to be carried out and the type of
self-propelled equipment to be used, whether owned demonstrating compliance by or subcontracted, and that they hold the corresponding site access permit documentary evaluation or the to enter the sites; records compiled.
Physical. ¾ Demonstrates that the operators of vehicles, machinery
and self-propelled equipment for the transport of materials comply with the following: 3 They carry out a visual inspection of the road conditions on winding and unstable terrain and, where
applicable, carry out or request the necessary conditioning work before
travelling on it; 3 They apply the user manual for loading, unloading and manoeuvres, established for that purpose, so as not to exceed the load capacity of the unit. In addition, the manual is available in the Spanish language on board the equipment; 3 They check that the load is properly positioned, secured and marked;
3 They wear the seat belt while
on board; 3 They are trained and instructed in the emergency procedures for controlling leaks or spills of the hazardous substances or materials transported, and 3 They report to the supervisor or person in charge of the site, for repair, any faults detected during the periodic inspection that compromise the safety of workers and facilities; Type of
Provision Acceptance criterion Remarks
evaluation
Records. ¾ Presents documentary evidence that
the general mechanical condition, bodywork, brakes, lights, tyres and integrity of the safety devices - switches, guards, protective devices, among others - are periodically checked, and the results are recorded in a logbook established for that purpose;
Physical. ¾ Demonstrates that the transport of personnel on
the running boards, mudguards, beds, buckets or scoops of
vehicles, machinery and self-propelled mobile
equipment used for transporting materials is prohibited, as well as on any other part not specifically designed for transporting personnel; ¾ Demonstrates that vehicles, machinery or self-propelled equipment used for transporting materials on construction sites have the following: 3 Audible devices - reversing alarms - to warn of reversing; 3 Personnel to assist operators with reversing manoeuvres, and 3 Safety devices, where applicable, such as cabs, belts, seat cushioning systems, or any other visual (beacon) or audible warning, identification or alarm device required according to the type of work to be carried out;
Documentary. ¾ Presents documentary evidence that there are
inspection and maintenance programmes for the vehicles, machinery or self-propelled equipment used for transport;
Physical. ¾ Demonstrates that vehicles, machinery or
self-propelled equipment used for transporting hazardous materials or substances in containers are fitted with attachments that prevent the free movement of
such containers, and with the
corresponding signage identifying their hazards; ¾ Demonstrates that it is ensured at all times that vehicles, machinery or self-propelled equipment used for transporting materials observe the safety distance referred to in clause 11.2, item o), of this Standard; ¾ Demonstrates that manoeuvres with vehicles, machinery or self-propelled equipment used for transporting materials that are carried out at critical points on the site, with narrow or busy accesses, in the presence of energised or pressurised equipment, or in complex reversing operations, are carried out with the assistance of personnel providing the operator with the appropriate safety signals; ¾ Demonstrates that tipper trucks are prohibited from travelling with the bed raised, and that, when loaded with soil, gravel or sand, such materials are covered with a tarpaulin; Type of
Provision Acceptance criterion Remarks
evaluation ¾ Demonstrates that roads, access routes and truck beds are sprayed with water to prevent the formation of dust clouds; ¾ Demonstrates that wheel stops are installed at the edges of slopes and fill embankments to prevent vehicles from reversing over them; ¾ Demonstrates that safety signage for the movement of vehicles, machinery and self-propelled mobile equipment is placed on the basis of the ground conditions, visibility or weather conditions, and ¾ Demonstrates that the priority for vehicle movement within the site is established as follows: 3 Emergency and rescue vehicles; 3 Official vehicles of the authorities; 3 Vehicles/equipment climbing very steep gradients;
3 Vehicles dedicated to transporting
personnel, and
3 Vehicles dedicated to transporting
materials.
Documentary ¾ Presents documentary evidence that: small, medium-sized
3 A record is kept of the site access permits for and large sites. vehicles, machinery and self-propelled demonstrating compliance
mobile equipment to be used, whether owned or by documentary evaluation
subcontracted, and or the records
3 Operators of vehicles, machinery and self-propelled compiled, of those measures| applicable, carry out or request | the |
| necessary conditioning work before | travelling on it |
5.11 and 16 The employer complies when: Applies to
Physical. ¾ Demonstrates that, for the installation of debris chutes, small, medium-sized
and large sites. the following safety measures are adopted: Small sites are exempted from 3 The chutes and the area
documentary evaluation type where debris is discharged are delimited and signposted; 3 Protective guard rails are fitted at the or the records compiled. debris-discharge openings; 3 The debris chute is secured to the structure; 3 The lower end of the debris chute is positioned at an angle; 3 The area where debris falls is continuously wetted, and 3 Ramps are provided to allow easy movement of wheelbarrows;
Physical. ¾ Demonstrates that, for the performance of
demolition work, the following safety measures are adopted: 3 The existence of gas, electrical power and water installations, or induced works, is investigated for their disconnection; 3 The area where demolition work will be carried out is delimited and signposted; 3 All glass and glazing present in the structure to be demolished are removed; 3 The supporting structure and unstable points are shored with sandbags, where work is carried out under load; 3 A single location is designated for the fall of removed material; Type of
Provision Acceptance criterion Remarks
evaluation 3 The area is enclosed with screens, partitions, hoardings or barriers; 3 Workers' exposure to dust is limited by means of: o Delimiting the work area and informing workers of the presence of hazardous substances or materials; o Decontaminating elements containing hazardous substances, and o Watering at suitable intervals the structures being demolished to prevent the formation of dust clouds; 3 Operatives are prevented from working at different levels on the same vertical plane; 3 Demolition begins from top to bottom, seeking to maintain a horizontal line; 3 The support points of structures holding up floors are prevented from being weakened while the work has not been completed; 3 Metal structures are dismantled floor by floor; 3 Debris is continuously removed so that access routes and work areas do not become obstructed, and to prevent overloading the structure; 3 Debris is discharged using discharge chutes for that purpose, and 3 Demolition work is halted in the event of strong winds or rain;
Physical. ¾ Demonstrates that, for pile driving,
the following safety measures are adopted: 3 The work area for the pile-driving machine and concrete-delivery trucks is levelled and compacted; 3 Stored piles are chocked to prevent them from rolling; 3 Piles are tied with ropes for unloading, and workers are prohibited from guiding them by hand; 3 All transmission mechanisms are protected with housings; 3 The steps and access points to the pile-driving machine are kept free of mud or grease; 3 Piles are prohibited from being dragged or pulled at an angle to bring them close to the driving location; 3 The reinforcement bars of the pile caps or heads are protected; 3 Operatives are prevented from remaining close to the piling machine in a way that they could be struck by it or by the shafts in suspension; 3 Unauthorised persons are prohibited from accessing the piling machine or remaining near the cab or manoeuvring areas, and 3 A radius of 10 m around the piling machine is secured to prevent impacts and being run over; Type of
Provision Acceptance criterion Remarks
evaluation
Physical. ¾ Demonstrates that, for the installation of
sanitary pipework, the following safety measures are adopted: 3 The work area is delimited and signposted in accordance with clause 11.2, item n), of this Standard; 3 The pipes for the pipelines are coupled on a horizontal surface, chocked with wooden wedges, to prevent them from slipping or rolling; 3 Manholes are covered or protected immediately after building them; 3 Collective protection is installed along open trenches; 3 The area is kept illuminated; 3 Pipe sections greater than 1.5 m in diameter are suspended at their ends, using slings, lifting lugs or balancing beams; 3 Pipes and/or materials are placed 2 m from the upper edge of the excavation; 3 Shoring is carried out with timber or other material on the sides of the excavation or trench; 3 Stockpiling is prevented at a distance of less than 2 m from the edge of the trench; 3 The placement of pipes in trenches is guided from outside; 3 Workers are prohibited from remaining inside the excavation while pipe is being placed by crane, and 3 Work is suspended in the presence of rain;
Physical. ¾ Demonstrates that, for the performance of work
involving the handling of energised equipment or installations, the following safety measures are adopted: 3 The work areas are delimited and signposted; 3 Tools protected with insulating material are used; 3 It is ensured that the routing of electrical supply lines does not coincide with that of temporary water-supply lines; 3 The energy-isolation procedure is established by means of tags and locks, and the use of dielectric personal protective equipment (gloves, footwear and helmet); 3 The site personnel are informed about the performance of functional tests on the electrical installation and the energy-isolation procedure; 3 Moisture- and dust-proof outdoor sockets are fitted; 3 The electrical panels are signposted; Type of
Provision Acceptance criterion Remarks
evaluation 3 Portable wooden or fibreglass ladders are used to carry out electrical network installation work; 3 In wet areas, the handling of electrical installations, the use of portable electric tools or extension leads, or the performance of electric welding, is avoided, and 3 Workers are prevented from wearing metal objects such as rings, chains, watches and earrings when carrying out activities on electrical installations or equipment;
Physical. ¾ Demonstrates that, for formwork fabrication and handling,
the following safety measures are adopted: 9 Signage is provided for the mandatory use of personal protective equipment in the area where formwork operations are carried out; 9 Nets, guard rails and signage are fitted at openings in the formwork to prevent workers from falling; 9 Workers ascend to and descend from the formwork by means of auxiliary equipment such as baskets, hoists or ladders; 9 Covers are fitted on the protruding ends of steel reinforcement. Where this is not possible, they are marked with signage; 9 Order and cleanliness are maintained during formwork operations; 9 Workers are prohibited from remaining in the area during the hoisting of planks, props and formwork reinforcement; 9 Nails or points present in the timber used are removed or clinched, as applicable. Nails that have been removed or are loose are collected in a specific location for subsequent disposal; 9 Stripping of formwork is carried out using metal bars, positioning oneself on the side from which the timber cannot come loose, and 9 The formwork elements removed are sorted for reuse or disposal;
Physical. ¾ Demonstrates that, for concrete handling and
placement, the following safety measures are adopted: 3 Wheel stops are placed at the edges for materials-transport trucks, in the case of pours
carried out in trenches, foundations and
excavations; 3 The maximum filling level of the buckets is marked so as not to exceed the permissible load; 3 Striking the formwork while emptying the buckets is avoided; Type of
Provision Acceptance criterion Remarks
evaluation 3 The pump pipework is supported on properly braced trestles during concrete pouring by pumping; 3 The concrete-pour hose is supported by at least two operatives; 3 A run of planks is provided on which the hose operatives can stand, before the pour begins; 3 The pouring of columns, vertical elements and formwork copings is carried out from scaffolding; 3 The pipework is prepared, greasing it and pumping the priming mortar, to prevent blockages and plugs from forming, before starting to pump the concrete; 3 It is checked that the formwork is firm and stable before pouring the concrete, and 3 The pouring of concrete is carried out, distributing it evenly inside the formwork in regular batches;
Physical. ¾ Demonstrates that, to carry out slab tile laying, it
adopts the following safety measures: 3 The material is stacked near the work area, clearing the location where the tile-laying tasks will be carried out; 3 The lower part of the area where the tile laying is carried out is delimited; 3 The materials for tile laying are handled in accordance with the provisions of NOM-006-STPS-2000, or those replacing it; 9 Materials are prohibited from being thrown down for use at the work site; 9 The minimum safety distance is observed, where tile-laying work is carried out near overhead electric power distribution lines, in accordance with Table 7 of this Standard; 3 A wooden hoarding and signage are fitted where tile-laying work is carried out at less than 3 m from live lines, and 3 Access by persons not taking part in these activities is prevented;
Documentary. ¾ Presents documentary evidence that
an up-to-date list is kept of the personnel who handle and use the sandblasting cleaning equipment;
Physical. ¾ Demonstrates that, for the performance of
sandblasting cleaning work, the following safety measures are adopted: 3 The compressed-air equipment (compressor), the safety devices (valves, gauges, relief vents), their connections, and the safe and operational condition of the hose, are inspected and tested before use; 3 The work area is protected and cleaned of the material and other particles removed, and Type of
Provision Acceptance criterion Remarks
evaluation 3 It is checked that, during the application of the sand blast: o The specific personal protective equipment is used; o The breathable air line for the worker is fitted with filtering devices to retain particles down to 5 microns, moisture and oil mist; o The dispersion of dust is prevented; o The area is kept delimited, signposted and restricted; o The safety data sheets (SDS) for the substances used for cleaning are available; o The shot-blasting equipment operator, and where applicable an assistant, are positioned in the application area; o The air line for the sand blast is connected independently of the breathable air line; o The air flow is cut off by means of the control valve when cleaning stops, and o The work clothing and/or the machine are cleaned without using compressed air;
Physical. ¾ Demonstrates that, for the performance of
painting, varnishing or coating work using solvent-based products, the following safety measures are adopted: 3 The work area is kept clean and tidy; 3 Workers are informed of the instructions set out in the safety data sheets (SDS) for the paints, solvents and substances they use; 3 The containers of varnishes, solvents, paints and other flammable liquids and gases used are labelled, in accordance with the provisions of NOM-018-STPS-2000, or those replacing it; 3 Solvent-based paints and varnish are prevented from being stored in damaged containers; 3 The containers of varnishes, solvents, paints and other flammable liquids and gases used are kept closed and away from ignition sources such as flames, sparks or cutting work; 3 Solvents are mixed with paints or varnishes only in the quantities required for the day's work; 3 Paint or varnish residues, and rags or waste soaked with solvents, are placed in closed containers, to prevent the formation of flammable atmospheres; Type of
Provision Acceptance criterion Remarks
evaluation 3 The work area is delimited and signposted in accordance with the provisions of NOM-026-STPS-2008, or those replacing it; 3 Dust-cleaning activities on walls, scraping and sanding are carried out under air-current ventilation; 3 The area or installation where painting, varnishing or solvent-based coating activities are carried out is kept ventilated; 3 Respiratory protection is used in places with the highest concentration of vapours; 3 An ABC-type fire extinguisher of at least 6 kg is available at the location where paint or solvent-requiring mixtures are prepared; 3 Smoking or eating is prohibited in places where painting is carried out with mixtures containing organic or toxic solvents; 3 All workers who come into contact with organic or toxic solvents wash their hands and face when they stop or finish the activity; 3 Testing of pipework, boiler or rail installations is prohibited while paint is being applied to them; 3 The use of solvents to clean the hands and skin of workers exposed to paints containing organic or toxic solvents is prohibited; 3 Common water-based cleaners are used, to prevent the absorption of harmful substances through the skin, and 3 The filters and the excess paint accumulated on them are periodically cleaned;
Physical. ¾ Demonstrates that, for the performance of spray-gun painting, varnishing or coating work using
solvent-based products, the following safety measures are adopted:
3 All connections are examined to
ensure they are correctly tightened before use; 3 The hoses are checked to be in good condition before opening the valve for operation; 3 The nozzle is held firmly when opening and closing the air supply; 3 Spills of solvents and paints are avoided, to prevent the formation of flammable atmospheres; 3 Hearing protection is used, and 3 The pressure-supply valves are closed on completion of the work; Type of
Provision Acceptance criterion Remarks
evaluation
Physical. ¾ Demonstrates that, for glazing installation, it
adopts the following safety measures: 3 Passage in ground-level areas is delimited, signposted and prohibited during installation; 3 The work area is kept free of obstacles and clear; 3 Glass panes are stored on timber and/or non-slip material; 3 Glass panes are stored, transported and placed always in a vertical position; 3 Glass panes are marked with paint or adhesive tape so that their presence is noticed during moving and installation; 3 Glass sheets are handled with safety suction cups; 3 The activity is suspended in the event of strong winds; 3 Other workers are prohibited from remaining or working on the vertical plane of the glazing installation area; 3 Work areas are kept free of glass fragments; 3 Scaffolding is used for glazing installation at height, and 3 The ground-level zone where glass is placed on balconies and open spaces at different levels is delimited, and
Physical. ¾ Demonstrates that, for the installation of electrical networks,
it adopts the following safety measures: 3 Cables crossing site roads are routed underground by means of conduits; 3 The site personnel are informed about the performance of functional tests on the electrical installation; 3 Moisture- and dust-proof outdoor sockets are fitted, and 3 Portable wooden or fibreglass ladders are used to carry out electrical network installation work.
where debris is discharged; demonstrating compliance
3 Guard rails are fitted at openings in the by documentary evaluation
facade, light wells or other openings through which or the records compiled, of those measures
debris is discharged; that involve a Physical ¾ Demonstrates that, for the performance of
painting, varnishing or coating work using solvent-based5.11 and 17 The employer complies when: Applies to
3 The operating risks and the safety conditions that involve documentary evaluation adopted to eliminate, reduce or control them; type or the 3 The assigned work area, and records compiled. 3 The type of fuel or energy used; ¾ Presents documentary evidence that written authorisation is granted by the employer or the person in charge of the construction site to the workers who carry out activities with machinery and equipment; Type of
Provision Acceptance criterion Remarks
evaluation ¾ Presents documentary evidence that it has a maintenance programme for the machinery and equipment used on construction sites; ¾ The maintenance programme for the machinery and equipment used on construction sites considers at least: 3 The asset or identification number;
3 The scheduled dates for carrying out
maintenance, and 3 The maintenance routines, including the checking of safety devices. The document recording the results of the routines is signed by the person in charge of the activity; ¾ Presents documentary evidence that it has safety procedures for carrying out maintenance activities on the machinery and equipment used on construction sites; ¾ The safety procedures for carrying out maintenance activities on the machinery and equipment used on construction sites comprise at least: 3 The equipment, tools and substances to be used; 3 The safety measures to be adopted in the area where maintenance is carried out; 3 The personal protective equipment to be worn by the worker carrying out the maintenance; 3 The safety measures to be applied to the equipment or machinery during maintenance, such as power isolation, and the fitting of locks and safety tags, and 3 The authorisations the worker obtains before carrying out the maintenance work;
Physical. ¾ Demonstrates that, for the operation of the machinery and
equipment used on construction sites, the following safety conditions are observed: 3 Those established in NOM-006-STPS-2000, or those replacing it; 3 The surrounding operating radius where activities are carried out with machinery and equipment is cordoned off; 3 It is checked that the machinery has its guards for moving parts fitted before operating it; 3 It is checked that the electrical and mechanical systems present no risk elements before starting operation; 3 It is checked, at the start of the work shift, as applicable, that the tyres show no
bulges, cracks, embedded objects or
deformation, and that they are at the correct pressure; 3 It is checked that the platforms of the machinery and equipment are free of grease and oil to prevent falls; Type of
Provision Acceptance criterion Remarks
evaluation 3 Personnel get on and off the machinery and equipment using the access steps; 3 The seat belt is always worn while driving the machinery and equipment; 3 Signage is fitted and the assistance of flag persons is used to control the movement of people and vehicles; 3 The machinery and equipment are driven at the permitted speed indicated in the traffic zone; 3 The vehicle is brought to a complete stop before crossing streets and other traffic routes; 3 The machinery and equipment are moved keeping the load-bearing elements - forks, bucket, boom, ripper, blade or drag bucket, among others - unlifted or in the operating position; 3 The machinery and equipment are kept at the safety distance referred to in clause 11.2, item o), of this Standard, as well as at a distance of at least 2 m from pipework, tanks and equipment containing hazardous fluids; 3 Overloading the machinery and equipment is avoided, even over short distances; 3 Driving the machinery and equipment on steep gradients exceeding the inclinations permitted for which they were designed is avoided; 3 Refuelling with the engine running is prohibited; 3 The machinery and equipment are prevented from being used as a means of transport; 3 Manoeuvres are suspended in the event of rain; 3 The machinery and equipment are parked on level ground at the end of the work and, where parked on a slope, chocks are placed alternately on the tyres, and 3 The parking brake is applied, the key is removed to prevent unauthorised starting or movement, and the operating implements are placed on the ground when leaving the machinery and equipment;
Physical. ¾ Demonstrates that, in the operation of air
compressors, the following safety measures are observed: 3 It is checked that the hoses are single-piece, without joints; 3 It is checked that the hoses show no cracks, joints, cuts or kinks; 3 It is checked that the hose connection mechanisms are secure; 3 The pressure hoses are kept protected with guards at pedestrian and vehicle crossings on the site roads; 3 The pressure hose is prevented from being used to clean material residue from clothing, and 3 It is checked that the hoses are fully extended when starting the compressor; Type of
Provision Acceptance criterion Remarks
evaluation
Physical. ¾ Demonstrates that, in the operation of electric power
generators, the following safety measures are observed: 3 It is checked that the main output switch is disconnected before starting the electric power generator, by means of the tag, lock and test system; 3 The generator's outlet is connected to an electrical panel, in such a way that a properly protected distribution tree is available for supplying several work fronts; 3 The lighting generator is fitted with a 300 mA residual-current device; 3 Earthing systems are installed for both the neutral
of the electric generator and for the
outlet; 3 The earthing system is secured against connection faults by using circuit breakers; 3 Access is restricted to authorised personnel only to the generator area and to its connections at electrical panels operating at 440 volts or more; 3 Signage is fitted on generators and electrical panels indicating the equipment capacity and the currents available at each outlet; 3 Metal objects such as rings, chains, watches and earrings are prevented from being worn in the generator area, and 3 The electric power generator is prohibited from being located in basements, enclosed or poorly ventilated places, and/or in damp areas;
Physical. ¾ Demonstrates that, in the operation of internal
combustion engines, the following safety measures are observed: 3 A space is available for refilling diesel and oil, fitted with equipment to collect any spillage; 3 All hose joints are kept free of oil and diesel, and 3 The machinery is earthed when refuelling, and
Physical. ¾ Demonstrates that, in the operation of cranes,
the following safety measures are observed: 3 The ground is prepared using mats, steel plates, timber matting, or structural or concrete mats to level and stabilise the crane; 3 The outrigger jacks are kept extended to fully unload the wheels and rest them on chocks; 3 The minimum safety distance is observed, where the crane is located near overhead electric power distribution lines, in accordance with Table 7 of this Standard; Type of
Provision Acceptance criterion Remarks
evaluation 3 Personnel are prevented from being transported in load containers, baskets, hooks, cables and other devices not designed for that purpose; 3 The hoist motors of mobile cranes are fitted with holding brake systems, electrically released and spring-applied; 3 The support outriggers are secured when using a crane with a telescopic boom; 3 The hooks are secured to prevent the cable or sling from slipping or coming out; 3 A signal code is used for all personnel involved in the manoeuvre; 3 The crane is prohibited from being used beyond its design capacity, in accordance with the manufacturer's tables for the manoeuvre parameters; 3 The crane is prevented from moving until the assistant is positioned in a location that allows maximum visibility of the crane's paths of travel and can direct its operation; 3 The load is prevented from being moved over people or the cab; 3 The load is raised 10 to 15 cm and the balance is checked before the moving manoeuvre; 3 The load is moved using at least two slings distributed at the working angles, so that there is no shifting; 3 The slings are positioned at a working angle of 45º to 60º on each of the lines supporting the load; 3 Personnel are prevented from remaining behind the crane's counterweight or within the slewing radius, or under the load to be lifted or moved; 3 The crane's maximum load capacity is displayed in a visible place, and 3 Artificial lighting is provided for night work in the manoeuvring area.
Documentary ¾ Presents documentary evidence that it has an small, medium-sized
up-to-date list of the machinery and equipment used; and large sites.
¾ The up-to-date list of the machinery and equipment Small sites are exempted from
used indicates, at least, for each item: demonstrating compliance by
3 The asset or identification number; documentary evaluation
3 The general description of its use; or the records
compiled, of those measures5.11 and 18 The employer complies when: Applies to
Documentary. ¾ Presents documentary evidence that: small, medium-sized
3 There are instructions on the and large sites. use, inspection, maintenance and safekeeping of Small sites are exempted from hand tools, and Workers are instructed on the handling, demonstrating compliance with maintenance and risk prevention of hand tools,
taking into account their limitations and possible failures; those measures
that involve documentary or Physical. ¾ Demonstrates that, in the use of hand tools, the records-based evaluation. following safety measures are adopted: 9 Personal protective equipment appropriate to the type of work being carried out or the tool being used is used, always observing the safety warning labels printed on the equipment; Type of
Provision Acceptance criterion Remarks
evaluation 3 It is checked that the handles of hand tools are hard and of a suitable size and are not slippery; 3 It is checked that the joint between the handles and the rest of the hand tool is firm, to prevent breakage from creating a hazard for the worker; 3 It is checked that hand tools have the guards necessary to prevent direct contact with their moving parts; 3 The operation of hand tools without their protective guards is prevented, where these were fitted by design; 3 It is checked that hand tools are of the size and characteristics suited to the use; 3 Burrs and filaments that could come off the accessories when using hand tools are removed; 3 Working with hand tools that are in poor condition or damaged is avoided; 3 Work with hand tools is carried out, preferably, on level surfaces; 3 Hand tools are placed in suspended locations and, if left on the ground, are protected or signposted appropriately; 3 It is checked that the workpiece is firmly secured and well positioned; 3 The parts forming the protective cover of hand tools are always kept in place; 3 Leaving hand tools in walkways, stairways and pedestrian traffic areas is avoided; 3 Work areas are signposted and delimited where the use of hand tools poses a risk to other workers, and 3 Test cuts are made where hand tools are used in places with electrical installations;
Documentary. ¾ Presents documentary evidence that a
written programme is established for the inspection and recording of hand-tool maintenance;
Physical. ¾ Demonstrates that, in the use of
electric tools, the following safety measures are adopted: 3 The modification of the power cable of hand-held electric tools is prevented, in accordance with the manufacturer's design; 3 The equipment is prevented from being used if the cable is scuffed, exposing the copper wires, or has joints made with insulating tape; 3 Double-insulated extension leads matching the tool's voltage, fitted with an earth-fault device and free of splices or tears, are used; Type of
Provision Acceptance criterion Remarks
evaluation 3 Flammable and combustible materials are removed when carrying out work with electric tools; 3 The parts forming the protective cover are always kept in place; 3 Hand-held electric tools are disconnected when stopping or finishing the activity, without pulling on the cable, and 3 Installation cables are joined using mechanical connectors;
Physical. ¾ Demonstrates that, in the use of cutting tools,
the following safety measures are adopted: 3 The tool is selected according to the material to be cut; 3 It is checked that the cutting elements show no excessive wear, cracks or fissures, and they are replaced immediately if they do; 3 Working in areas with poor access is avoided, as is forcing the position of the tool's cutting element; 3 The ring test is carried out on the cutting disc to check that it is in safe and operational condition; 3 It is checked, when working with cutting tools, that there are no pipes carrying gas or hazardous substances; 3 Cutting elements are used in accordance with the tool's rated speed; 3 The generation of sparks during and at the end of work with cutting tools is controlled; 3 The area of concrete to be cut is periodically wetted; 3 A dust extractor is used or the work is carried out in open areas; 3 It is checked that the securing elements of the cutting tools are secure, and 3 Cutting elements are replaced when they reach the end of their service life as established by the manufacturer;
Physical. ¾ Demonstrates that, in the use of
pneumatic tools, the following safety measures are adopted: 3 It is checked that the supply network is compressed air and not another gas, where the pneumatic tool is connected to a general network; 3 The use of gaseous oxygen as a power source for the pneumatic tool is prohibited. Only filtered, lubricated and compressed air is used; 3 It is checked that taps and valves on the pneumatic-tool supply network are working properly; Type of
Provision Acceptance criterion Remarks
evaluation 3 The safe and operational condition of the pneumatic tool, as well as of the connecting hose and its joints, is checked; 3 It is checked that the length of the hose is sufficient and suitable for the work to be carried out; 3 The correct coupling of the pneumatic tool to the hose is ensured; 3 The compressed-air pressure is kept constant, the compressor's oil level is checked, and water accumulation is prevented; 3 The maximum pressure recommended by the manufacturer is prevented from being exceeded, and it is checked that the line pressure is compatible with the elements or tool to be used; 3 The trigger of pneumatic tools is prohibited from being squeezed while the tool is being loaded; 3 Pneumatic tools are prevented from being carried by the hose or squeezed while being moved; 3 It is checked that the compressed-air supply hose is kept as far away as possible from the work area; 3 The safe and operational condition of the hoses and connections is periodically checked, discarding those that are broken or deteriorated. No joints are made in the hoses; 3 The oil in the lubricators is periodically replenished, using that specified by the equipment manufacturers; 3 The use of petrol or other flammable liquid to clean the pneumatic tool is prohibited; 3 The pneumatic tool is disconnected from the air hose before clearing blockages, and servicing and adjustments are carried out only while it is not in use; 3 The use of control valves that allow air to remain in the pneumatic tool is avoided; 3 The hoses of pneumatic tools are prevented from resting on the ground and, where applicable, from being placed in areas where they could be damaged by the passage of moving elements; 3 Hoses are protected with planks or in small trenches where they have to cross site machinery; 3 Periodic breaks are taken or tasks are alternated, and 3 Workers are prohibited from directing air jets at people or using them to clean clothing, and Type of
Provision Acceptance criterion Remarks
evaluation
Physical. ¾ Demonstrates that, in the use of tools that
run on liquid fuel, the following safety measures are adopted: 3 Workers are prevented from being near a fire, smoking, or using them while refuelling; 3 Spills during filling are avoided and cleaned up immediately if they occur; 3 The machine is prohibited from being started in the same place where it is refuelled, and 3 It is checked that there are no leaks at the joints, to prevent risks of fire or explosion.
5.12 Physical. The employer complies when it demonstrates that it has fire extinguishers to fight possible incipient fires, according to the type of fire that may occur in the different areas of the construction site, the inventories of substances and the materials used, in accordance with NOM-002-STPS-2010, or those replacing it.
5.13 Physical. The employer complies when it demonstrates that the machinery and equipment used on the construction site has protection systems and safety devices, in accordance with the provisions of NOM-004-STPS-1999, or those replacing it.
5.14 Documentary. The employer complies, where applicable, when it presents documentary evidence that it has the operating authorisations granted by the labour authority for the pressure vessels and boilers used on construction sites, in accordance with NOM-020-STPS-2002, or those replacing it.
5.15 Physical. The employer complies when it demonstrates that it has safety signage to indicate the risks at each phase of the construction site and for the use of personal protective equipment, on the basis of the provisions of NOM-026-STPS-2008, or those replacing it.
5.16 a) and 19.1 The employer complies when:
to 19.3 Documentary. ¾ Presents documentary evidence that it has an
emergency response plan; ¾ The emergency response plan for construction sites classified as small contains: 3 A list of the actions for emergency response, including those relating to first aid; 3 The person responsible for implementing the actions; 3 The resources for assisting personnel, including the first-aid kit, and 3 The telephone numbers for requesting assistance from the fire brigade, hospitals, police and rescue services; ¾ The emergency response plan for construction sites classified as medium-sized contains, in addition to the provisions of clause 19.1, the following: 3 The internal and external communication procedure in the event of an emergency, together with a directory for locating the person in charge of the construction site, and 3 Instructions for evacuation; fire-fighting, and first aid, and Type of
Provision Acceptance criterion Remarks
evaluation ¾ The emergency response plan for the various phases of construction sites classified as large contains: 3 The scope of the plan; 3 The person responsible for implementing the plan; 3 The human and material resources for putting it in place; 3 The training of workers in relation to the content of the plan; 3 The frequency and type of emergency drills to be carried out; 3 The personal protective equipment required for emergency response; 3 The evaluation and feedback of the emergency response plan; 3 The description of the facilities, the activities to be carried out and the surroundings; 3 The analysis of internal and external risks, including natural phenomena; 3 The inventory of the material resources available to deal with emergency situations; 3 The operating instructions for the control and
management of the potential emergencies
resulting from the risks detected, together with those for the personnel who activate the plan; 3 The identification of evacuation routes, assembly points and/or safety zones; 3 The procedures for: o Raising the alarm, in the event of an emergency; o Internal and external communication, in the event of an emergency, together with the directory for locating, at any time of day, those responsible for the preventive occupational safety and health services and for the construction site; the emergency assistance services (fire brigade, hospitals, police and rescue), as well as, where applicable, the directory of the information centres for handling chemical substances in emergencies; o The shutdown of machinery and equipment; o The suspension of activities; o The evacuation of workers and visitors; o First aid; o The elimination of risks after the emergency; o The assessment of damage, and o The return to normal operating activities, and 3 The setting-up of the emergency response teams, with the assignment of posts and responsibilities, specifying the personnel trained and instructed for: o Emergency and disaster response; o Evacuation; o First aid, and o Fire-fighting. Type of
Provision Acceptance criterion Remarks
evaluation
5.17, 20.1 and The employer complies when: Applies to
20.2 Documentary. ¾ Presents documentary evidence that the training large sites. is provided in accordance with programmes prepared for that To demonstrate purpose; ¾ The training programmes relating to compliance by interview,
knowledge of 3 the construction site safety and health programme, and the phases of the site; 3 the safety instructions, and the content of the
applicable to carrying out the activities or work, and the use, maintenance, upkeep, storage and replacement of personal protective equipment.
5.17, 20.3 and The employer complies when: Applies to
| activities carried out by the workers relate | compliance shall be |
| to: | considered met when at |
| 3 Each phase of the site; | least 90 per |
| 3 The content of the construction site safety and health | cent of the personnel |
| system; | interviewed has |
| Documentary | ¾ Presents documentary evidence that the training provided to workers includes: 3 Information on the occupational risks relating to the activity they will carry out; 3 The safe way to handle or use machinery, equipment, tools, materials and substances; 3 The safety measures to be adopted to carry out the activities or work, and 3 The use, maintenance, upkeep, storage and replacement of personal protective equipment, in accordance with the provisions of Chapter 7 of NOM-017-STPS-2008, or those replacing it, or | the construction site safety and health system; the construction site safety and health programme; the occupational risks relating to the activity they will carry out; the safe way to handle or use machinery, equipment, tools, |
| Interview | ¾ When interviewing workers, selected in accordance with the sampling criterion of Table 9 of clause 23.4, it is confirmed that they have knowledge of the topics on which they were informed and trained. | materials and substances; the safety measures to be adopted |
20.4 Documentary. ¾ Presents documentary evidence that: medium-sized sites. 3 The information provided to To demonstrate compliance workers who carry out hazardous work is provided before the start of such by interview,
activities, and that the occupational safety and health talks provided to them relate to the risk prevention, protection and control measures and to the safety instructions applicable to the activities they carry out. Type of
Provision Acceptance criterion Remarks
evaluation
Interview. ¾ When interviewing workers, selected in
accordance with the sampling criterion of Table 9 of clause 23.4, it is confirmed that: 3 They have knowledge of the hazardous work they carry out, and that the information was provided to them before the start of such activities, and 3 The occupational safety and health talks provided to them relate to the risk prevention, protection and control measures and to the safety instructions
applicable to the activities they
carry out.
| 3 The occupational safety and health talks that | compliance shall be |
| are provided to workers are | considered met when at |
| related to the prevention, | least 90 per |
| protection and control measures for risks and to the | cent of the personnel |
| safety instructions applicable to the | interviewed has |
| activities carried out by the workers, or | knowledge of the hazardous work that |
5.18 Documentary. The employer complies when it presents documentary evidence Applies to medium-sized that it provides contractors, subcontractors and and large sites. suppliers with information on the risks that may arise in the phase of the construction site where they will carry out their activities, so that they comply with the provisions of the construction site safety and health system.
5.19 Documentary. The employer complies when it presents documentary evidence that it set up at least one safety and hygiene committee on the construction site, and supervises that the committee performs its functions, in accordance with the provisions of NOM-019-STPS-2011, or those replacing it.
5.20 Documentary. The employer complies when it presents documentary evidence that it has preventive occupational safety and health services, on the basis of the provisions of NOM-030-STPS-2009, or those replacing it.
5.21 and 9.4 The employer complies when: Applies to
Documentary. ¾ Presents documentary evidence that it authorises in medium-sized and
writing the workers who carry out hazardous large sites. work, in accordance with the provisions of clause 9.4 of this Standard, and ¾ The authorisations to carry out hazardous work contain at least: 3 The name of the authorised worker; 3 The type of work to be carried out and the area or place where the activity will be performed; 3 The date and time of commencement of the activities, and the estimated completion time; 3 The safety measures applicable in accordance with the results of the risk analysis for each activity, and 3 The name and signature of the employer or of the person designated to grant the authorisation.
5.22 Documentary. The employer complies when it presents documentary evidence that it grants contractors, subcontractors and suppliers the site access permits they require to enter and carry out their activities on the site.
5.23 Physical. The employer complies when it demonstrates that it provides workers with a hygienic area for eating, in accordance with the provisions of the Official Mexican Standards issued in that regard by the Ministry of Health. Type of
Provision Acceptance criterion Remarks
evaluation
5.24 Physical. The employer complies when it demonstrates that it provides workers with temporary drinking-water services and sanitary facilities - washbasins, toilets, urinals, among others - in accordance with the provisions of the Official Mexican Standards issued in that regard by the Ministry of Health, or with the local and environmental legislation on the matter.
5.25 The employer complies when: Applies to
Physical. ¾ Demonstrates that it provides, as applicable, accommodation large sites.
for workers, depending on the size, type and location of the construction site, and ¾ Where the construction site has camps for accommodating workers, these are fitted out in accordance with the provisions of
the relevant Official Mexican Standards
of the Ministry of Health and, where applicable, with the provisions of the collective labour agreement.
5.26 Documentary. The employer complies when it presents documentary evidence that, where applicable, it notified the Ministry of Labour and Social Welfare of the occupational accidents and illnesses that occurred on the site, in accordance with the provisions of NOM-021-STPS-1993, or those replacing it.
5.27 and 21 The employer complies when: Applies to
Record. ¾ Presents the record of occupational accidents; medium-sized and
large sites. ¾ The record of occupational accidents contains, at least, the following: 3 The type of accident that occurred; 3 The frequency and severity indicators for monitoring its incidence; 3 The pattern of occupational accidents, according to the activities and phases of the site, and 3 The follow-up on the safety measures adopted after an accident, based on the results of the investigation;
Documentary. ¾ Presents documentary evidence that it carried out the
investigation of the occupational accidents that occurred, and ¾ The investigation of the occupational accidents that occurred comprises at least: 3 The identification of the general details of the injured person;
3 The causes of the accident, including the
hazardous or unsafe conditions and/or unsafe
acts that caused the accident,
illness or material damage; 3 The consequences of the accident, specifying the part of the body injured, and the type of injury and/or material damage caused; Type of
Provision Acceptance criterion Remarks
evaluation 3 The sequential description of the accident and of the mechanism of exposure; 3 The assessment of the accident, with the probability of occurrence and severity of the harm; 3 The activities or measures that should have been in place to prevent the accident; 3 The follow-up on the accident and the safety measures implemented; 3 The history of previous occupational illnesses and injuries suffered by the injured worker; 3 The outcome of the investigation, and 3 The proposed safety measures that shall be adopted, whether in the near or immediate term, based on the results of the investigation, to prevent the accident from recurring.
23.4 For the selection of workers to be interviewed to verify compliance with the provisions of this conformity assessment procedure, the sampling criterion contained in Table 9 below shall apply: Table 9 Random sampling Total number of workers Number of workers to be interviewed 1-15 1 16-50 2 51-105 3 More than 105 1 per 35 workers up to a maximum of 15
23.5 Documentary evidence or the records held at the workplace may be presented in printed form or on magnetic media, and shall be kept for one year.
24. Monitoring
Monitoring compliance with this Standard is the responsibility of the Ministry of Labour and Social Welfare.
25. Bibliography
25.1 Safe practices in the construction industry. Ministry of Labour and Social Welfare, 2006.
25.2 NMX-SASST-001-IMNC-2000, Occupational safety and health management system, 2000.
25.3 Research project on the safety, hygiene and working environment conditions prevailing in the construction industry. Mexican Chamber of the Construction Industry (CMIC), 1999.
25.4 Research project on the safety, hygiene and working environment conditions prevailing in the construction industry. Mexican Chamber of the Construction Industry (CMIC), 2006.
25.5 Practical guide for the prevention of occupational risks on construction sites. Generalitat Valenciana, 2001.
25.6 Construction in Mexico/Technology and Services. TECNIMEXICO, S.A. de C.V., 1982.
25.7 Study on the safety and working environment conditions prevailing in the construction industry. Training programmes. AREC Consultores, 2003.
25.8 Regulatory impact statement. AREC Consultores, 2003.
25.9 Federal District Building Regulations, published in the Federal District Official Gazette of 29 January 2004.
25.10 Encyclopaedia of Occupational Health and Safety. International Labour Organization (ILO), 2000.
25.11 Means and systems for complying with physical RMGs, Continental Europe, Middle East and Africa. CEMEA, Bovis Lend Lease, 2008.
25.12 TECHINT, S.A. de C.V. Safety, Health and Environment Management System, 2009.
25.13 Low-Cost Industrial Safety and Occupational Health - A practical approach. Arellano Díaz Javier, Correa Flores Alejandro, Doria Orta Hugo Arturo, Editorial Politécnico, 2008.
26. Concordance with international standards
This Standard does not concord with any International Standard, since no reference existed at the time it was drafted.
TRANSITIONAL PROVISION
SOLE. This Official Mexican Standard shall enter into force six months after its publication in the Official Gazette of the Federation.
Reference Guide I
Signage on Construction Sites The content of this guide is a supplement for a better understanding of the Standard and is not mandatory. I.1 Signage is a measure: a) To reinforce the training and instruction of workers in matters of occupational safety and health; b) Used when it is necessary to promote safety actions, to prevent risks or reduce them, and c) Complementary to the technical and administrative measures of prevention and personal or collective protection. I.2 Occupational safety and health signage is used as a result of the risk analyses, in normal situations or foreseeable emergency situations, and when the preventive measures adopted reveal the need to: a) Inform of the existence of risks, prohibitions or obligations; b) Warn of an emergency situation requiring urgent protective or evacuation measures; c) Enable workers to locate and identify particular protective, evacuation or first-aid means or facilities, and d) Orient or guide workers and visitors performing particular activities or manoeuvres in areas considered hazardous. I.3 The signage used in the different areas and phases of the site, as applicable, covers the following: a) Entrance to and exit from the site; b) Mandatory use of personal protective equipment; c) Caution in hazardous work; d) No smoking; e) Location of first-aid equipment; f) Location of fire-fighting equipment; g) Location of high-voltage lines; h) Warning of the presence of lorries and cranes, among others, and i) Location of safety barriers to delimit pedestrian and vehicle crossing areas, work areas, and vehicle traffic areas. Given in Mexico City, Federal District, on the eleventh day of the month of April of the year two thousand and eleven.- The Minister of Labour and Social Welfare, Javier Lozano Alarcón.- Signature.