Chemical Safety – An Overview

The control of risk from the use of harmful substance is as much a matter for effective management as any other aspect of industrial or commercial success or failure., R. R. Nair

1.0 INTRODUCTION:

Of all the industries, the chemical industry uses most of the hazardous chemicals having a significant bearing on safety, health and environment problems encountered in running any industry. Although there is no universal consensus as to the scale of production and use of chemicals, it is estimated that the average annual world production of chemicals is more than 400 million tons. As per an ILO document of 1987, as back as in 1978, the American Chemical Society’s Chemical Abstract Services identified 4 million distinct chemical compounds and it has been calculated that this number is increasing at the rate of over a quarter of a million every year.  It is accepted that few of these substances and compounds are used commercially. However the United States Environmental Protection Agency (EPA) suggest that about 70,000 chemical compounds can be considered as being in everyday use. World Health Organization (WHO), the Organization for Economic Co-operation and Development (OECD) and the EPA estimated that new chemicals in excess of one ton placed on the market each year range from 200 to over 1000, most of which, until recently, have not been tested for deleterious effects. ILO’s book entitled “Occupational Exposure Limits for Airborne Toxic Substances”, lists occupational exposure limits for 1,178 chemical substances which, have been adopted by various countries. This number constitutes but a small fraction of chemicals in use.

With increasing sophistication of processes and severity of process parameters, the possibilities of something going wrong have assumed a far greater magnitude. The magnitude of exposure of working population to chemicals is not known with any certainty. A variety of chemicals are used in the field of agriculture, which is accounting for fifty percent of the total world workforce. Most of these workers among the least protected. In the same way that the scale of use of chemicals in the developing countries is increasing, day by day, so is the apparent trend in occupational diseases and illness. Adequate statistics on occupational diseases and injuries, due to exposure to chemicals at work are not easy to find even in developed countries.  This is due to different criteria of recognition, classification and reporting of diseases and injuries among other factors.  However, as per an article published in “Safety Science” 44 (2006), the average figure of global occupational accidents, was estimated to be 264 million accidents yearly, so more than 7,00,000 workers in a day suffer an accident which causes absence of 3 days or more.

In India approximately 10 million persons are employed in various factories. As per the Directorate General Factory Advice Service and Labour Institutes (DGFASLI), more than 36,500 hazardous factories out of the 3,00,000 registered factories, employs 20,46,092. No precious data is available for the occupational ill-health or injuries caused in the chemical industry in India. However, the current burden of accumulated occupational diseases in India is estimated to be about 18 million cases.

Harmful chemical pollutants in the workplaces may be generally categorized into three different groups, viz. (i) Toxic Chemicals, (ii) Flammable Chemicals, and (iii) Explosive Chemicals.  The exposure of these chemicals can lead to many hazards, which can be broadly be grouped into two viz.: (i) Toxic Hazards and (ii) Fire and Explosion Hazards.

2.0 TOXIC HAZARDS:

Toxic chemicals or materials include simple and chemical asphyxiates, irritants, narcotics, systemic poisons, carcinogens, teratogens, mutagens and those with dermatological effects.
The hazards arising from exposure to toxic materials depend on the circumstances of the exposure and the nature of chemicals involved.  Such exposure range from sudden brief exposure, perhaps at high concentrations, to prolonged exposure at low, often changing concentrations over a period of years which may be as long as a working lifetime.  In most cases, exposure will be to a range of chemicals of varying degrees of harmful potential, with perhaps synergistic effects between some of the substances involved.

The routes of entry of toxic chemicals are: (i) Inhalation – probably the most common industrial case, (ii) Ingestion – frequent as a route for industrial poisoning except through eating and smoking without adequate attention to hygiene and (iii) Skin absorption via external contact.

Generally, dusts, fumes, gases and vapours are inhaled and liquids and solids are ingested or penetrate the damaged or undamaged skin.

Once on or in the body, the toxic material may have varying effects.  There are local effects when the material is an irritant to the skin, eye or respiratory tract; or there is a systemic effect because of the substances toxicity.  Delayed effects may be carcinogenic while other substances may involve fetal or chromosome damage.

2.1 Toxic Hazard Control:

There are three basic measures applicable to the control of toxic substances.  These are (i) Substitution, (ii) Engineering Controls and (iii) Personal Protection.  A combination of measures are often used to achieve an appropriate level of control.  These measures are:

a) Substitution of less toxic material
b) Enclosure of the harmful process or substance
c) Isolation of the process or harmful substance
d) Local exhaust ventilation
e) General ventilation
f) Wet methods
g) Personal protection equipment and clothing.

Many harmful substance in industry have irritant or allergenic properties, causing dermatitis, perhaps in addition to other toxic characteristics.  They may act as the skin, or on the respiratory tract, or both.

3.0 FIRE AND EXPLOSION HAZARDS:

The fire and explosion risks associated with many chemicals present an acute hazard both to property and to life.  While fire is normally regarded as having a disaster potential less than that of explosion, fires tend to occur more frequently and are extensively documented. There have been substantial losses due to fire and explosion. Even where there has not been hazard to life, major product losses have been reported world-wide. The numerous standards and code of practices applicable to storage are, for this reason, concerned primarily with risk of explosion and fire.

Storage, handling and internal transport of flammable materials pose many problems, especially on account of spillage and similar risks.

There are a number of risks of explosions including chemicals, to which workers may be exposed.  These can be caused by: the detonation of explosive materials, the detonation of deflagration of gas or vapour cloud which are within flammable limits, or the detonation of dust cloud in confinement.  These may result in overpressure or the individual being hit by debris or suffering directly or indirectly from the effect of the blast which damages the building. Organic peroxides and some azo and nitro-compounds, have unstable properties and may be formed as intermediates in chemical reactions, or by the inadvertent, or accidental mixing of incompatible substances.  Boiling liquid expanding vapour (BLEVES) are not confined to large scale installations although it is these which have received the greatest attention.  A BLEVE need not involve flammable materials.  In all cases, the initial effect may be the generation of a blast wave and missiles and the expanding vapour cloud, if ignited, will produce thermal radiations.  Explosions in a chemical process plant may include mist and spray explosions, superheated liquid explosions, compressed air or other gas system explosions.

Explosion – preventions measure may involve complex engineering procedures.  These may include control of the atmosphere by the use of inert gas, and explosive protection and relief by containment, separation, flame arrestors, automatic isolation, suppression and wetting.

A particular hazard in the process industries is that of dust explosions.  Many industrial materials are at some stage handled as dusts or powders and many final products are in finely divided dust or powder from which will form explosive mixtures in the air.  The risk is not only of primary explosions within the plant but of secondary must larger, explosions in buildings in which dust has been allowed to collect on beams, ledges and fittings as a result of poor housekeeping. Incidents involving dust explosions have been recorded for many years; these particularly affected have been flour milling, grain storage, and metal powder manufacturers.

4.0 NATIONAL LEGISLATIONS:

Given the considerable increase in and complexity of chemical substances in use today, new legislations in this field has been promulgated in some countries and existing legislations in other countries is being amended and updated.

Although national legislations may contain provisions relating to the use and handling of harmful substances, the type and content of legislations differs from one country to another depending on the degree of industrialization, size, geography, and work related practices.  In developing countries the emphasis has been placed on the import, use, and handling of chemicals, whereas in industralised countries, equal emphasis has been laid on the control of production of chemicals.

Legislation in some countries notably Australia, Canada, the Federal Republic of Germany, Hungary, Japan, the Russian Federation, the United Kingdom and the United States are task-oriented.  In others, legislation is broad-based or general in its provision.

In the USA, in addition to the general provisions of the Occupational Safety and Health Act 1970, there are several standards applicable to the chemical industry.  Also in the USA, Toxic Substances Control Act 1976 provides for the compilation of information on all chemicals.

As far as India is concerned many provisions relating to chemical safety has been incorporated in the existing legislations after the Bhopal Tragedy. The Factories Act, 1948, which is mainly concerned with factories, has been amended to incorporate many provisions relating to chemical safety.

The Government of India has even formulated a new act i.e. Environment (Protection) Act in 1986 and a series of legislations have been brought under this Act.  In view of the appearance of health hazards associated with particular chemical substances, specific laws have been passed by different countries or rules formulated under existing general legislation.

4.1 Identification and Labelling:

Requirements for identification and labelling of chemical substances exist in several countries including India.  Requirements differ from one country to another as to the details of the components of identification and labelling.

4.2 Transport:

National regulations or guidelines regarding transport of chemicals within the enterprise only exist in few countries.  However more attention is given to external transport.  In India, transport of chemicals is dealt with the Motor Vehicles Act, 1988 and the Central Motor Vehicles Rules, 1989.

4.3 Storage:

Most chemicals in the work place are held in storage, prior to distribution and use. This storage may be in one or each of several locations at the manufacturers, suppliers, in transit or at the work place, before, or during after use. Considerable quantities of harmful materials may be stored in ways which may have the potential in the event of an incident, to cause several hazards not only to workers but also to the population in the vicinity of the place of storage and general environment. There have been many such incidents involving flammable, explosive and toxic materials.  The incidents involving explosive materials at Oppau, Germany, in 1921, flammable material at San Juan Ixhuatepec, Mexico, in 1984 and toxic material at Bhopal, India, in 1984 and Switzerland in 1986 are few examples.  General or specific legislation on storage of chemicals exists in various countries including India. Because of the associations with major accident hazards and incidents, such as those in Flixborough (1974) and Seveso (1976), storage of chemicals became a major accident component of the EC Directive on major accident hazards. Standards for the storage of toxic materials tend to be contained in guidance notes, MSDS, codes of practices and manufacturer’s code.  In India, storage of chemicals is mainly dealt with the Factories Act, 1948 and the Environment (Protection) Act, 1986.

4.4 Handling and Use:

Legislation on handling and use of chemicals at work is available in several countries.  In EC, extensive provisions exist on the safe handling and use of chemicals aimed at both the “no risk” and “acceptable risk” philosophies.  System similar to that of the EC exist elsewhere in the world including USA and India.  In India, safe handling and use of chemicals is mainly dealt with the Manufacture, Storage and Import of Hazardous Chemicals (MSIHC) Rules, 1989. The amended Factories Act 1948 also dealt with chemical safety in a separate chapter.

4.5 Waste Disposal:

The Law and practice regarding waste disposal within the enterprise differs markedly from one country to another.  In the United Kingdom, disposal of waste within the enterprise is provided for in several acts of legislation notably the Health and Safety at Work Act 1974 and the Public Health Acts.  The control of waste in general is mainly dealt with under the Control of Pollution Act 1974.  The EC has Directives on waste disposal.  In India the control of waste in general is mainly dealt with the Hazardous Wastes (Management and Handling) Rules 1989.

5.0 ROLE OF THE ILO:

ILO activities, designed to stimulate or to reinforce national action in occupational safety and health are promoted through, the International Programme for Improvement of Working Conditions and Environment (PIACT).

Despite the considerable activities of the ILO in the field of occupational safety and health, there is no comprehensive instrument which deals with the control of all chemical substances at workplace, though there are few Conventions and Recommendations, which are mostly in general terms. The following ILO Conventions (C) and Recommendations (R) have direct or indirect relevance to the control of chemicals at work:

1. White Lead (Painting) – C 013;
2. Protection Of Workers’ Health – R 097
3. Radiation Protection – C 115 and R 114
4. Hygiene (Commerce & Office) – C 120 and R 120
5. Benzene – C 136 and R 144
6. Occupational Cancer – C 139 and R 147
7. Working Environment (Air pollution, Noise and Vibration) – C 148 and R 156
8. Occupational Safety And Health (Dock Work) – C 152 and R 160
9. Occupational Safety And Health – C 155 and R 164
10. Occupational Health Service – C 161 and R 171
11. Asbestos – C 162 and R 172
12. Chemicals – C 170 and R 177
13. Prevention of Major Industrial Accidents – C 174 and R 181
14. List of Occupational Diseases – R 194

6.0 CONCULSION:

The control of risk from the use of harmful substance is as much a matter for effective management as any other aspect of industrial or commercial success or failure. It is also important to all levels from government and multinational levels, through the range of workplaces, to be self-employed.  It has become the practice in many countries, to have a written policy containing a definite and defined commitment by top management to take care of the safety, health and welfare of all its employees. Such policies to be effective need to be implemented at all levels – for performance and effectiveness. For implementation of an effective safety and health policy in chemical industry, it would be desirable to carry out Safety, Health and Environment Audits; HIRA; HAZOP; and HAZAN, which would help in identifying the potential hazards involved and seek appropriate remedial measures.

7.0 REFERENCES:

1. EC – Council Directive of 27 June 1967 and amendments on the Classification, Packaging and Labelling of Dangerous Substances.
2. ILO – Meeting of Experts on Harmful Substances in Work Establishments: Report on the use of chemicals at Work, Geneva, 1987.
3. ILO – Occupational Exposure Limits for airborne toxic substances (Occupational Safety and Health Series No. 37), Geneva 2nd (revised) ed., 1980.
4. ILO – Occupational Safety and Health Convention No. 155 and Recommendation No. 164, Geneva, 1981.
5. India – The Environment (Protection) Act, 1986.
6. India – The Factories Act, 1948 and its amendments adopted in 1987.
7. India – The Hazardous Wastes (Management and Handling) Rules 1989.
8. India – The Manufacture, Storage and Import of Hazardous Chemicals (MSIHC) Rules, 1989
9. India – The Motor Vehicles Act, 1988 and the Central Motor Vehicles Rules, 1989.
10. Lees – Loss Prevention in the Process Industries – 1986.
11. Nair, R.R.  & Alappad, Vinod – Safe Transport of Hazardous Chemicals by Road, Industrial Safety Review, August 2015.
12. Nair, R.R.  & Chakravorti, S. – Safe Handling of Hazardous Chemicals, All India Council for Technical Education – CEP, Bangalore, 2001.
13. Nair, R.R.  & Joshi, D.K. – Safety and Loss Prevention in Process Industries, All India Council for Technical Education – CEP, Bangalore, 2002.
14. Nair, R.R. – Bhopal Tragedy, Fasli News, Vol. I No. 2, 1984.
15. Nair, R.R. – Exposure of chemicals and their effects on the body, Industrial Safety Review, May 2012.
16. Nair, R.R. – Fire and Explosion Hazards, Industrial Safety Review, January 2013.
17. Nair, R.R. – Hazards of Anhydrous Ammonia, Safety and Health Information Bureau, Navi Mumbai, 1989.
18. Nair, R.R. – Hazards of Benzene, Safety and Health Information Bureau, Navi Mumbai, 1989.
19. Nair, R.R. – Hazards of Carbon Disulphide, Safety and Health Information Bureau, Navi Mumbai, 1989.
20. Nair, R.R. – Major Fires: Have We Learnt Lessons From The Past? Industrial Safety Review, May 2016.
21. Nair, R.R. – Major Hazard Works, Fasli News, Vol. II No. 3, 1986.
22. Nair, R.R. – Occupational Health in India, Industrial Safety Review, April 2016.
23. Nair, R.R. – Potential hazards of chemicals, Industrial Safety Review, February 2012.
24. Nair, R.R. – Safe handling of compressed gases, Industrial Safety Review, March 2012.
25. Nair, R.R. – Safe Handling of Corrosives, Industrial Safety Review, April 2012.
26. Nair, R.R. – Workplace Accidents are Increasing, Science Today, September 1982.
27. Ramaswamy, S.S & Nair, R.R. – Statutory Provisions on Occupational Health and Safety, and Environment Safety in India, All India Council for Technical Education – CEP, Bangalore, 2000.
28. UK – Health and Safety at Work Act, 1974.
29. UK Health and Safety Executive – The Classification, Packaging and Labelling of Dangerous Substances Regulations, 1984 HMSO, London, 1984.
30. UN – United Nations Code of Practice on the transport of dangerous goods, New York, 1977.
31. USA – Occupational Safety and Health Act, 1970.

About Author
Mr. R. R. Nair has more than 50 years’ experience in Occupational Safety, Health & Fire Protection.  He has carried out about 80 projects in SHE Pan India (Safety Audits, Accident Investigations, Environmental Studies, Hazard Identification and Risk Assessment (HIRA), Hazardous Zone Classifications, Fire Safety Audits in High Rise Buildings, etc.). He is author of 15 books and about 75 articles in various topics on SHE.
 He can be contacted on:
M: +91 7045172050, Resi: +91 477 2266994
E-mail: ceo@shib.co.in / shib@vsnl.com
Website: www.shib.co.inp