NOM-005-STPS-1998, Safety and health conditions in workplaces for the handling, transport and storage of hazardous chemical substances

Whereas on 3 December 1993 Official Mexican Standard NOM-005-STPS-1993, on safety conditions in workplaces for the storage, transport and handling of flammable and combustible substances, was published in the Official Gazette of the Federation; Whereas this Ministry, on the basis of the first paragraph of the fourth transitory article of the Federal Regulation on Occupational Safety, Health and Working Environment, published in the Official Gazette of the Federation on 21 January 1997, has considered it necessary to make various amendments to that Official Mexican Standard, the purpose of which is to bring it into line with the provisions laid down in that regulatory instrument; Whereas on 27 January 1998, in compliance with article 46, paragraph I, of the Federal Law on Metrology and Standardisation, the Ministry of Labour and Social Welfare submitted the preliminary draft amendment to this Official Mexican Standard to the National Advisory Committee for Standardisation on Occupational Safety, Health and Working Environment, and on that same date that Committee found it to be correct and agreed that it should be published in the Official Gazette of the Federation; Whereas, so as to comply with the guidelines contained in the Agreement on the deregulation of business activity, published in the Official Gazette of the Federation on 24 November 1995, the amendments proposed to this Standard were submitted by the Ministry of Trade and Industrial Development to the Economic Deregulation Council for its opinion, and on the basis of that opinion the appropriate adjustments were made, whereupon that Ministry issued a favourable ruling on the amendments contained in this Standard; Whereas on 15 May 1998, in compliance with the Committee's Agreement and with article 47, paragraph I, of the Federal Law on Metrology and Standardisation, the Draft Amendment to this Official Mexican Standard 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 aforementioned National Advisory Committee for Standardisation on Occupational Safety, Health and Working Environment; Whereas, having received comments from 2 submitting parties, that National Advisory Committee for Standardisation examined them and ruled on them in due course, and this Ministry published the respective replies in the Official Gazette of the Federation on 22 October 1998, in compliance with article 47, paragraph III, of the Federal Law on Metrology and Standardisation. Whereas, in view of the foregoing considerations and given that the National Advisory Committee for Standardisation on Occupational Safety, Health and Working Environment granted its approval, the following is hereby issued: Official Mexican Standard NOM-005-STPS-1998, Safety and health conditions in workplaces for the handling, transport and storage of hazardous chemical substances

Reference guide. First-aid kit

To establish the safety and health conditions for the handling, transport and storage of hazardous chemical substances, so as to prevent harm to and protect the health of workers and to avoid damage to the workplace.

This Standard is in force throughout the national territory and applies in all workplaces where hazardous chemical substances are handled, transported or stored.

For the correct interpretation of this Standard, the following Official Mexican Standards in force shall be consulted: NOM-004-STPS-1994, on protection systems and safety devices on machinery, equipment and accessories in workplaces. NOM-010-STPS-1993, on safety and health conditions in workplaces where chemical substances capable of generating contamination of the working environment are produced, stored or handled. NOM-017-STPS-1993, on personal protective equipment for workers in workplaces. NOM-026-STPS-1993, Safety, colours and their application. NOM-027-STPS-1993, Safety and health signs and notices. NOM-028-STPS-1993, Safety - Colour code for the identification of fluids conveyed in pipework. NOM-114-STPS-1994, System for the identification and communication of hazards from chemical substances in workplaces.

For the purposes of this Standard the following definitions are laid down: a) hazardous activity: a set of tasks arising from work processes that generate unsafe conditions and overexposure to chemical agents capable of causing harm to the health of workers or to the workplace. b) explosive atmosphere: an area of the workplace in which the ambient concentration of hazardous chemical substances lies between 20% of the lower flammability limit and the upper flammability limit. c) non-respirable atmosphere: an area of the workplace with a deficiency, less than 19.5%, or an excess, more than 23.5%, of oxygen. d) labour 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. e) workplace: any place, whatever its name, in which production, marketing or service-provision activities are carried out, or in which persons work who are subject to an employment relationship. f) confined space: a place large enough, and so configured, that a person can perform a given task inside it, which has limited or restricted means of access or exit, which is not designed to be occupied by a person on a continuous basis and in which specific work is carried out occasionally. g) pre-placement medical examination: an examination carried out and determined by a physician to ascertain the physical and mental condition of the worker so as to determine whether or not it is feasible for the worker to be exposed to the hazardous chemical substances present in the workplace. h) specific medical examination: an examination carried out by a physician, the content of which is determined by the specific literature. It is carried out where a change in the worker's health is suspected, with the aim of making a thorough medical assessment with respect to the hazardous chemical substances to which the worker is exposed in the workplace and of being able to recommend corrective action to the employer. i) periodic medical examination: an examination carried out and determined by a physician, the purpose of which is to monitor the health of the worker exposed to the hazardous chemical substances present in the workplace. j) primary explosives: materials that can readily be made to detonate by heat, spark, fire or friction, for which reason they are used as initiators and in most cases are of low stability. k) secondary explosives: materials that require a primary explosive or a detonating agent for their initiation. l) instability: a characteristic of those chemical substances which, by virtue of their physical and chemical properties, alter their state of equilibrium when energy is applied to them. m) fire-resistant material: non-combustible materials which, when subjected to the action of fire, neither transmit it nor generate smoke or toxic vapours, and which do not fail structurally for a period of at least two hours. n) explosives magazine: premises intended for the storage of explosive substances. o) safe procedure: an ordered and logical sequence of activities for carrying out a task in such a way that the risks to which the worker is exposed are minimised. p) potential risk: the probability that a hazardous chemical substance will cause harm to the health of workers or to the workplace. q) combustible substances: those in a solid or liquid state with a flash point above 37.8°C. r) corrosive substances: those in a solid, liquid or gaseous state that cause destruction or irreversible alteration of living tissue by chemical action at the site of contact. s) explosive substances: those in a solid, liquid or gaseous state which, upon an increase in temperature or pressure over a portion of their mass, react suddenly, generating high temperatures and pressures on the surrounding environment. t) flammable substances: those in a solid, liquid or gaseous state with a flash point of 37.8ºC or below, which ignite easily and burn rapidly, generally in a violent manner. u) irritant substances: those in a solid, liquid or gaseous state that cause a reversible inflammatory effect on living tissue by chemical action at the site of contact. v) hazardous chemical substances: those which, by virtue of their physical and chemical properties, when handled, transported, stored or processed, present the possibility of flammability, explosiveness, toxicity, reactivity, radioactivity, corrosiveness or harmful biological action, and may affect the health of exposed persons or cause damage to installations and equipment. w) reactive substances: those that are liable to release energy. x) toxic substances: those in a solid, liquid or gaseous state that may cause structural or functional disorders leading to harm to health or death if absorbed, even in relatively small quantities, by the worker. y) ventilation: the system for the supply and extraction of air, by natural or artificial means, by which the conditions of the air in the working environment can be modified as regards the concentration of contaminants, temperature and humidity.

5.1 To show the labour authority, at its request, the documents that this Standard requires it to draw up.

5.2 To draw up and keep up to date, as regards changes to processes or to the hazardous chemical substances present in the workplace, a study to analyse the potential risks of hazardous chemical substances in accordance with section 7.1.

5.3 To draw up and keep up to date the procedure manuals for the safe handling, transport and storage of hazardous chemical substances, which shall include the identification of the containers.

5.4 Based on the results of the study to analyse the potential risk, a sufficient number of showers, eyewash units, neutralisers and inhibitors shall be available in the risk areas for dealing with emergencies.

5.5 Based on the results of the study to analyse the potential risk, where the work activity is such that the deposit of hazardous chemical substances on the worker's skin or clothing may be a risk to health, a sufficient number of showers, changing rooms and lockers shall be available for the workers and, where appropriate, a clothes-cleaning service shall be provided.

5.6 Based on the results of the study to analyse the potential risk, a first-aid manual shall be available defining the medicines and dressing materials that the workplace requires and the procedures for dealing with medical emergencies; the reference guide included at the end of this Standard may be taken as a reference.

5.7 To provide the medicines and dressing materials needed to give first aid, in accordance with section 5.6.

5.8 To assign, train and instruct staff to give first aid.

5.9 To provide personal protective equipment, in accordance with the study to analyse the potential risk and with NOM-017-STPS-1993.

5.10 To have installations, equipment or materials for containing hazardous chemical substances, so that in the event of a spill of liquids or a leak of gases their run-off or dispersal is prevented.

5.11 To establish in writing the hazardous activities and the operations in confined spaces which involve exposure to hazardous chemical substances and which require authorisation before they may be carried out, and to draw up the authorisation procedure in accordance with section 7.2.

5.12 To draw up a Specific Safety and Health Programme for the Handling, Transport and Storage of Hazardous Chemical Substances, in accordance with Chapter 8.

5.13 To train and instruct workers in the Specific Safety and Health Programme for the Handling, Transport and Storage of Hazardous Chemical Substances.

5.14 To have a preventive maintenance programme for machinery, equipment and installations.

5.15 To draw up and keep for at least twelve months a record of the corrective and preventive maintenance applied to the equipment, indicating when it was applied.

5.16 To inform workers of the risks to which they are exposed.

5.17 To ensure that pre-placement, periodic and specific medical examinations are carried out on workers who are exposed to hazardous chemical substances.

6.1 To comply with the safety measures established by the employer.

6.2 To take part in the training and instruction provided by the employer.

6.3 To comply with the instructions for the use and maintenance of the personal protective equipment provided by the employer.

6.4 To take part in the emergency response teams.

6.5 To undergo the medical examinations appropriate to the activity performed and indicated by the employer.

7.1 The study to analyse the potential risk shall be carried out taking the following into consideration: a) the characteristics of the work processes; b) the physical, chemical and toxicological properties of the hazardous chemical substances; c) the degree and type of risk of the substances, in accordance with NOM-114-STPS-1994; d) the hazardous activities and the work in confined spaces, e) the risk areas of the workplace and the number of workers exposed in each area.

7.2 Authorisation procedure for carrying out hazardous activities. A document shall be drawn up containing: a) a description of the activity; b) the name of the worker who is to carry out the activity; c) the place where the activity will be carried out; d) the time and date scheduled for the start and completion of the activity; e) the personal protective equipment to be used; f) the name and signature of the person responsible for the authorisation; g) the name and signature of the person responsible for the area where the hazardous activity will be carried out, who shall oversee that activity; h) the name and signature of the maintenance manager acknowledging notice, i) the safe procedure for carrying out the activity shall be attached.

hazardous chemical substances This programme shall contain the following: a) the safety data sheets for all the chemical substances handled, transported or stored in the workplace, in accordance with NOM-114-STPS-1994; b) the cleaning and housekeeping procedures; c) the maximum quantities of the substances that may be held in the production area, based on the study to analyse the potential risk; d) the type of personal protective equipment specific to the risk; e) the procedure for cleaning, disinfecting or neutralising clothing and protective equipment that could become contaminated with hazardous chemical substances, where the study to analyse the potential risk so indicates; f) the prohibition on consuming food and drink in the work areas; g) the workplace emergency plan, which shall contain the following: 1) the safety procedures in the event of a leak, spill, emission or fire; 2) the first-aid manual in accordance with section 5.6; 3) the evacuation procedure; 4) the procedures for returning to normal conditions, 5) the procedures for rescue in confined spaces. h) the prohibition on smoking and using open flame in the areas where this represents a risk, i) the safe procedures for carrying out hazardous activities and work in confined spaces.

9.1 Based on the study to analyse the potential risk, the signs, notices, colours and identification of fluids conveyed in pipework shall be placed in accordance with NOM-026-STPS-1993, NOM-027-STPS-1993 and NOM-028-STPS-1993.

9.2 Containers holding hazardous chemical substances in the liquid state at atmospheric pressure shall be filled to a maximum of ninety per cent of their capacity, for which purpose a device for reading the filling level shall be provided.

9.3 Portable pressure vessels containing hazardous chemical substances shall: a) be fitted with valves and pressure gauges; the reading of the operating pressure on the gauge shall be below the maximum working pressure, b) have the maximum working pressure marked on them. Fire extinguishers and aerosols are exempt from compliance with this section.

9.4 Fixed containers for the storage of hazardous chemical substances shall have fire-resistant foundations.

9.5 Pipework and fixed containers holding hazardous chemical substances shall be fitted with systems that allow the flow of those substances to be interrupted.

9.6 Specific areas shall be provided for the storage of hazardous chemical substances.

9.7 Containers holding hazardous chemical substances shall be identified in accordance with NOM-114-STPS-1994.

9.8 Containers with hazardous chemical substances shall remain closed while they are not in use.

9.9 In the areas where, owing to the type of activity, there is no frequent exposure of workers to hazardous chemical substances, care shall be taken to ensure that the concentration of those substances in the working environment does not create an explosive atmosphere. Where a worker has to enter one of these areas, measures shall be taken to control the worker's exposure.

9.10 For work in confined spaces, the following shall be complied with: a) the authorisation procedure shall be drawn up in accordance with section 7.2; b) the isolation of the energy, machinery and equipment related to the confined space where the work will be done shall be carried out, and safety tags shall be placed indicating that their use is prohibited while the work is being carried out; c) the interior shall be monitored constantly to verify that the atmosphere meets the following conditions: 1) that the oxygen content is between 19.5% and 23.5%; otherwise the appropriate measures shall be taken, both for the use of air-supplied respiratory protective equipment and for carrying out activities in non-respirable atmospheres; 2) the concentration of flammable gases or vapours shall not at any time exceed 20% of the value of the lower flammability limit; Example: Formic acid has a lower flammability limit of 18 on a volume/volume basis, so 3.6 is the value that shall not be exceeded. 3) the concentration of hazardous chemical substances shall not exceed the maximum permissible exposure limits laid down in NOM-010-STPS-1993; otherwise the control measures laid down in that standard shall be applied, 4) the lamps used to light a confined space shall be heavy-duty and explosion-proof. d) whenever a worker enters a confined space to carry out work, that worker shall be closely watched by the person responsible for the area or by a person trained for this function, and shall also use a harness and a rope resistant to the chemical substances present in the confined space, long enough to allow manoeuvring within the area and to be used to rescue the worker if necessary.

9.11 Where an artificial ventilation system is provided, it shall be operated under a programme of maintenance and supervision of its functioning.

flammable or combustible substances

10.1 In the areas of the workplace where these substances are handled, transported or stored, the walls, floors, ceilings, installations and foundations shall be of fire-resistant materials.

10.2 On handling.

10.2.1 The use of tools, clothing, footwear and personal items that may generate a spark, open flame or temperatures capable of causing ignition is prohibited.

10.2.2 The decanting of flammable or combustible substances shall be carried out with sufficient ventilation or isolation of the process to prevent the presence of explosive atmospheres.

10.3 On storage.

10.3.1 The areas intended for this purpose shall be isolated from any source of heat or ignition.

10.3.2 The fixed containers in which these substances are stored shall be fitted with pressure-relief devices and a flame arrester.

10.4 On transport.

10.4.1 The pipework systems conveying these substances that are exposed to possible damage from the normal movement of workers or equipment shall be provided with protection to prevent them from being damaged. This protection shall not impede the inspection and maintenance of those pipework systems;

10.4.2 Where transport is carried out in portable containers, these shall be closed.

explosive substances

11.1 On handling.

11.1.1 A procedure manual shall be drawn up for the safe handling of explosives, which shall establish at least the following: a) the instruction to suspend work when an electrical storm or tempest is approaching; b) the use of tools, clothing, footwear and personal items that may generate heat, static discharges, sparks or open flame is prohibited, as is bringing in any electronic device that generates radio frequency; c) explosive substances shall be handled exclusively by staff trained and authorised by the employer; d) before blasting is carried out it shall be verified that: 1) a warning siren is installed and operating, with a range of more than 500 metres around the site where the blasting will take place, so as to warn of the danger any person within the perimeter of that site. This siren shall operate continuously for 10 minutes before the firing begins and for 10 minutes after the last blasthole has been fired; 2) all the workers have been moved away from the blasting area; 3) staff have been posted at all the points of access to the place where the blasting is to be carried out, so as to prevent the entry of any person, 4) all the workers have reached a safe shelter. e) it is prohibited to return to the place where the blasting was carried out until trained staff have checked that the area is in a safe and healthy condition and authorisation to return to that area has been given; f) if there are indications of a misfire in any blasthole, the workers shall not return to their activities until authorised and trained staff have located all the blastholes that did not detonate and the necessary safety measures have been taken; g) where primary and secondary explosives have to be used, they shall be handled separately and shall be brought together only when the operation so requires; h) explosives which, owing to their instability, present initiation risks shall be handled in a wet state; i) only authorised staff, under supervision, shall be present inside the premises intended for the storage of explosive substances; j) only the workers authorised by the employer may have access to the inside of the premises intended for the storage of explosive substances; k) vehicles entering the explosives-magazine area to load or unload explosive substances shall do so with a spark arrester on the exhaust pipe and a conductive strip for the discharge of static electricity.

11.2 On storage.

11.2.1 Explosives magazines shall have marked-out movement areas so as to allow the stacking, unstacking and handling of these substances.

11.2.2 The operation of the explosives magazine shall be directed by an authorised person who knows and applies the operating procedures and the safety measures.

11.2.3 The explosives magazine shall be kept under control as regards cleanliness, temperature and ventilation.

11.2.4 Where work is carried out in explosives magazines, personal protective equipment shall be used consisting of: a) 100% cotton clothing with an antistatic finish; b) 100% cotton underwear, c) protective footwear with a conductive sole and no metal parts.

11.3 On transport.

11.3.1 It shall be carried out exclusively by staff duly trained and authorised by the employer.

11.3.2 It shall be carried out by means of equipment or safety systems that prevent explosion from impact, spark or heating.

corrosive, irritant or toxic substances

12.1 The storage of corrosive, irritant or toxic substances shall be carried out in specific containers made of materials compatible with the substance concerned.

12.2 Where the transport of corrosive, irritant or toxic substances within workplaces is carried out through a pipework system or in portable containers, these shall be closed to prevent their contents from spilling or leaking.

Enforcement of compliance with this Standard is the responsibility of the Ministry of Labour and Social Welfare.

Federal Regulation on Occupational Safety, Health and Working Environment, Title II, Chapter VI, Title III, Chapter III. Published in the Official Gazette of the Federation on 21 January 1997, Mexico.

This Standard does not correspond to any international standard, as no such reference existed at the time of its drafting.

FIRST.- This Standard shall enter into force sixty days after its publication in the Official Gazette of the Federation. SECOND.- During the period indicated in the preceding article, employers shall comply with the Official Mexican Standards NOM-005-STPS-1993, on safety and health conditions in workplaces for the storage, transport and handling of flammable and combustible substances; NOM-008-STPS-1993, on safety and health conditions for the production, storage and handling of explosives in workplaces; NOM-009-STPS-1993, on safety and health conditions for the storage, transport and handling of corrosive, irritant and toxic substances in workplaces; NOM-018-STPS-1993, on the requirements and characteristics of the shower, changing-room and locker services in workplaces, and NOM-020-STPS-1993, on the medicines, dressing materials and staff giving first aid in workplaces, or shall carry out the adaptations needed to observe the provisions of this Official Mexican Standard and, in the latter case, the labour authorities shall provide, at the request of the interested employers, advice and guidance for putting compliance into effect, without the employers becoming liable to penalties for non-compliance with the standards in force. THIRD.- Upon the entry into force of this Standard, the following Official Mexican Standards are cancelled: NOM-008-STPS-1993, on safety and health conditions for the production, storage and handling of explosives in workplaces, published in the Official Gazette of the Federation on 3 December 1993. NOM-009-STPS-1993, on safety and health conditions for the storage, transport and handling of corrosive, irritant and toxic substances in workplaces, published in the Official Gazette of the Federation on 13 June 1994. NOM-018-STPS-1993, on the requirements and characteristics of the shower, changing-room and locker services in workplaces, published in the Official Gazette of the Federation on 6 December 1993. NOM-020-STPS-1993, on the medicines, dressing materials and staff giving first aid in workplaces, published in the Official Gazette of the Federation on 24 May 1994. Effective Suffrage. No Re-election. Mexico, Federal District, on the fifteenth day of the month of December of nineteen ninety-eight.- The Minister of Labour and Social Welfare, José Antonio González Fernández.- Signed. REFERENCE GUIDE FIRST-AID KIT The content of this guide is a supplement for a better understanding of the Standard and is not mandatory. It is based on the First Aid Manual of the Mexican Red Cross. First-aid kit: The set of materials, equipment and medicines used to give first aid to a person who has suffered an accident or a sudden illness. TYPES OF FIRST-AID KIT: The type of kit shall be according to the type of activity to be carried out or to the site where it is located. CHARACTERISTICS The following are mentioned as important characteristics for the first-aid kit: easy to carry, visible and easily accessible, identifiable by a visible red cross, not excessively heavy, without padlocks or devices that hinder access to its contents, and with a list of the contents. CARE The following care is recommended: a) that it be kept in a cool, dry place; b) that the instruments be clean; c) that the bottles be closed and preferably made of plastic; d) that the medicines have not expired, e) that the material be kept in order. If surgical instruments such as scissors, forceps or needles are held, these shall be packed, either in small cloth wraps or in absorbent paper, and labelled with the name of the instrument they contain. The material making up the first-aid kit may be classified as follows: a) dry material; b) liquid material; c) instruments; d) medicines, e) supplementary material. It shall be borne in mind that the quantity of material is to be appropriate to the use for which it is intended and to the financial means available. All the material mentioned is basic and shall be present in any first-aid kit. DRY MATERIAL Dry material is that which, by its characteristics, is to remain in that state, and it comprises the following items: a) cotton wool swabs; b) gauze of 5 x 5 cm; c) gauze compresses of 10 x 10 cm; d) adhesive tape; e) elastic roll bandages of 5 cm x 5 m; f) elastic roll bandages of 10 cm x 5 m; g) gauze bandages with the same dimensions as the two preceding items; h) bandage with 4, 6 or 8 tails; i) tongue depressors; j) cloth dressings or adhesive bandages, k) triangular bandage. LIQUID MATERIAL This comprises the following solutions: a) benzalkonium; b) tincture of iodine, known as “isodine espuma”; c) neutral soap, preferably liquid; d) petroleum jelly; e) alcohol, f) boiled or sterile water. As mentioned above, the foregoing solutions shall preferably be in plastic containers, with a reasonable quantity of swabs, and each labelled to make their use easier. INSTRUMENTS The instruments may consist of the following: a) straight scissors and button-tipped scissors; b) straight Kelly forceps; c) dissecting forceps without teeth; d) thermometer; e) rubber tourniquet, f) disposable syringes of 3.5 and 10 ml with their respective needles. MEDICINES This material is left to the judgement of the physician responsible for the emergency service and shall be used under the strict control of the physician. SUPPLEMENTARY MATERIAL This is material that may or may not form part of the first-aid kit or that, owing to its use, requires specific material; for example, for hikers it is advisable to include anti-scorpion serum or an antidote for snakebite. Some items that may be included are: a) hand torch; b) twine; c) surgeon's gloves; d) umbilical cord ligature; e) stethoscope and sphygmomanometer; f) splints, of wood or cardboard; g) a blanket; h) mosquito repellent; i) cotton buds, j) pencil and paper.