The needs and requirements of all those working with chemical substances are covered by various Acts and other requirements and are a complex matter. The Occupational Health & Safety Act (Act No 85 0f 1993) is the main Act and was drawn up in consultation with employers and trade unions. This act deals with all aspects of health and safety in the workplace. While it places responsibility upon the employer to provide safe working conditions it also places obligations on the worker to act responsibly. The Act places particular emphasis on the duty to inform:-

The employer to warn his employees of any hazards they are likely to encounter in the workplace

The manufacturer or the supplier to inform any customers of any hazards associated with a product or its use.

It is therefore essential for anyone working in the chemical industry to understand the potential dangers of substances used and so protect themselves, their fellow workers and their workplace.

The drum or package of chemical, whilst still in the store, may contain a substance with dangerous properties, but it will be perfectly safe until someone interferes with it, the drum corrodes, the building catches fire or some other change takes place. Only then does a hazard arise. It is important to understand what constitutes a dangerous property, how this can become a hazard and what steps we must take to ensure not only the safety and wellbeing of ourselves, but also that of our fellow workers and our workplace. In this way, if we understand the dangers, then the substance can be handled correctly and so we can avoid or minimise the risk.

The words hazard and risk have special meanings in regulations and guidance about substances at work and the difference between them is important for a correct understanding of the control of hazardous substances.

Hazard The hazard presented by a substance is its potential to cause harm. It could make your skin sore or damage your lungs.

Risk The risk from a substance is the likelihood that it will harm people in the actual circumstances of use. This will depend on many factors, including:

the hazard presented by the substance; how it is used (or misused);how exposure to it is controlled;how much of the substance you are exposed to and for how long; the work being done

Remember that there can be a substantial risk even from a substance that is not particularly hazardous, if exposure is excessive.

With proper precautions, the risk of being harmed by even the most hazardous substance can be very small.

Safe exposure levels have not only been established for chemicals but also for physical conditions such as illumination, sound, heat, and humidity and various standards have been laid down. These will be found in the various regulations issued under the OHS Act.

Different chemical substances affect the body in different ways and so we classify them as acute, chronic, local, or systemic.

ACUTE – refers to an immediate effect – that is in minutes, hours or days. An example of this would be an acid or ammonia, where one contact has an obvious result.

CHRONIC – refers to those which have a delayed action or which build up in the body – this can take weeks, months or years. Examples are lead, asbestos and certain solvents and certain chemicals known as sensitisers.

LOCAL – applies when the effect is limited to a specific area of the body, usually the point of contact. Solvents (dermatitis), acids & strong alkalis are examples.

SYSTEMIC – applies to chemicals that affect the organs of the body such as the liver, kidneys and the brain. Examples would be lead, mercury and certain solvents such as alcohol…

Some substances fall into one or more of these categories. A example of a chemical which can exhibit all of these four types of toxicity is Phenol. It burns the skin immediately at the point of contact and so its effect is acute and local. It is absorbed into the body and affects the liver and kidneys and so its effect is therefore also chronic and systemic.

SENSITISERS. After one, or sometimes repeated, contact these substances can produce an allergic type response from the body. This can affect the skin, the breathing or both. Exposure to these substances can mean that a person can become sensitised and a minimum exposure can give an immediate response. Some epoxy compounds and other chemicals such as amines and the isocyanates are examples.

EXPOSURE TO AIRBORNE SUBSTANCES. The air around us will contain varying amounts of chemicals whose presence (and hazard) is not always obvious. However, most chemicals have been assessed for their potential to cause harm and the Department of Labour has set allowable concentration levels. These are known as OCCUPATIONAL EXPOSURE LIMITS (OEL’s) and substances are grouped into two classes, each having different OEL’s

CONTROL LIMITS (OEL – CL) – where there are likely to be serious implications for the health of persons exposed to the substance. These are maximum exposure limits, which should not normally be exceeded. Furthermore, exposure should be reduced below these limits as far as is reasonably practicable by means of engineering controls and not personal protective equipment

RECOMMENDED LIMITS (OEL-RL) – where there is no indication that the substance is likely to be injurious to persons if they are exposed day after day to the stated airborne concentration. Engineering controls should likewise be used to reduce exposure to levels as low as is reasonably practical, but PPE may also be used as an additional measure.

In addition, there are SHORT-TERM EXPOSURE LIMITS (STOEL), which are maximum allowable concentrations measured over a short period (usually 15 minutes). If a STOEL has not been assigned, then it is considered to be three times that of the OEL.

The law requires that when hazardous substances are to be used, the working environment must be monitored at regular intervals to ascertain that the exposure levels are below the prescribed limits.

Exposure levels can be controlled by use of good working practices and by engineering control measures ( e.g. ensuring that dust and/or vapour emissions are contained and adequate ventilation is provided).

Personal protection must be made available to cater for periods of high concentrations and at such times the relevant area must be demarcated with the correct sign .

More details, including tables showing OEL’s, are to be found in the Schedule attached to the OHS Act

It is important to understand that the effects of chemicals may not be immediately obvious. On the other hand the more unpleasant ones are not necessarily the most dangerous. Think of snakes and spiders – if you can’t identify them – give them all a wide berth. You would be careful with any spider or snake no matter how harmless it looked. Those who work with them must first learn to identify which ones are dangerous. Unfortunately familiarity can lead to unnecessary risks being taken.

An examination of some 3000 different materials used and made in the paint industry shows that only a fifth of these represent any major hazard to health and only a quarter of these are really serious.

As no worker can be expected to remember the potential hazard for each of these substances, each substance used is classified so that the user will know the degree of danger and how to protect himself. The way it works is as follows:-

The SABS has published a Recommended Practice (ARP 006:1991) entiltled “A guide to health hazards and personal protection in the paint industry”. This provides a simple way for any worker to recognise the health hazard potential of the raw materials in use and to determine the personal protection equipment to be used should it be required. The degree of danger to health for each substance is placed into one of four categories as follows:-.

GROUP 4 – MINIMAL. Minimally hazardous substances are substances that are reasonably safe under all normal conditions of use. No residual effect is to be expected from accidental exposure even if no treatment is applied.

GROUP 3 – SLIGHT. Slightly hazardous substances are substances that require some sort of safeguards but are otherwise safe under normal conditions of use. Minor residual effect(s) could result from accidental exposure if no treatment is applied.

GROUP 2 – MODERATE. Moderately hazardous substances are substances that are to be handled with caution and careful regard for personal protection. Minor residual effect(s) could result despite prompt treatment and cumulative/chronic effects are possible.

Note:- Substances with potential for chronic effects should be considered for this group or group 1

GROUP 1 – SERIOUS. Seriously hazardous substances are substances that are to be treated with extreme caution., and either have to be handled with specialised equipment or personal protection has to be worn, or both. Major residual effect(s) could result despite prompt treatment, and severe chronic effects are possible.

Note:- These ratings apply to use under normal ambient conditions. Variations such as use at elevated temperatures must be given due consideration.


These are grouped as follows.

A  A suitable overall and gloves would be a basic requirement.
B  Dust mask.
C  Eye protection. (Splash and/or vapour)
D  Dust mask & Eye protection. (Splash and/or vapour).
E  Respirator & Eye protection. (Splash and/or vapour).
F  Impervious clothing & full eye protection
G  Full Face Respirator or hood & Impervious clothing.
J  Full skin cover with air-fed hood.
K  Special conditions & extra care! – Here we are not only concerned with the worker(s) directly involved but also those working nearby.

Combining the Health Hazard rating number with the letter indicating the Personal Protective Equipment (PPE) required makes up a rating for each chemical. These two symbols are separated by a letter “H” and the Health Hazard rating are shown in the form “3HC”, “2HE” etc. Boards showing this information are prominently displayed to assist in interpreting the code easily & quickly. This rating is shown on the batch sheets. Any worker not sure should ask his supervisor to assist in assessing the degree of hazard and the level of protection needed.

The use of personal protection equipment is recognised not only to be uncomfortable and clumsy but it also reduces the workers efficiency. It is for these reasons that it should be looked upon as a protection at times of unacceptable exposure. It is also in the workers own interest to maintain his PPE properly.

LIQUIDS – The PPE board does not define the exact form of face protection. The actual requirements are defined by a consideration of the physical nature of the substance(s) being handled & the concentration .

A face shield will protect against splashes to the face and the eyes. Goggles will be appropriate if only the protection of the eyes is involved. The PPE letter in the HHR must be properly interpreted. – see categories “F”, “G” & “J”. “F” indicating only a splash problem “G” indicates fumes as well as splash. The apron and boots signs indicate corrosivity.

In the lower ratings a choice between goggles and a face shield would be needed. Goggles will be required as protection for the eyes from irritating fumes but the rest of the skin remains exposed. Should you be handling a substance such as Hydrochloric Acid or Ammonia, which give off irritating vapours, even at concentrations below that requiring the use of a full-face respirator, goggles will be as protection against fumes but a full face-shield would still be needed as a skin protection. In the case of a corrosive liquid such as caustic soda, the skin of the face would need to be protected.

The minimum protection is eyeshields and while ordinary spectacles will give some splash and particulate protection they can also be damaged. It is advisable to wear eyeshields which go over spectacles especially the type which has side shields.

It is probably better to use a face or eye shield whenever any splashing is indicated. Skin is much more resilient than eyes.

If you are unsure ask your supervisor – it is your right to have eye protection. The OHS Act requires eye-wash facilities to be available. Make sure you know where they are and how they operate.

FUMES AND VAPOURS – There are several types of respirators available and the one issued to you should be correct for the type of substances which you are likely to use. As soon as the smell of vapours is coming through then the canister should be changed. In the case of Isocyanates the vapours can pass through the normal respirator after a relatively short exposure and they can cause problems at very low levels. Special areas are set aside for the use of these substances.

DUST – Dust masks are designed for protection against dust and are useless as a protection against gases or vapours. Dusts can cause eye problems and goggles should be used with those substances with the PPE rating “D”.

AEROSOLS – are finely divided particles of a liquid such as paint, suspended in air as we get when spraying. These particles could clog the filter canister and so reduce its efficiency Where Aerosols and high dust levels are possible, respirators with a dust/particle filter should be used. These dust filters should be replaced often.

Exposure to chemicals must be considered from two aspects. These are the general levels that occur during the normal work period and higher levels that will occur irregularly when loading a reactor or mixer.

For these reasons different exposure levels have been set and these have been taken into consideration in assessing the hazard potential of each chemical used in the workplace. As there are instances of sudden increases in exposure levels such as when a manhole is opened or a vessel charged, it is only common sense to use Personal Protective Equipment (PPE) as indicated at such times.

No matter in which form the chemical comes, personal cleanliness and habits are very important. Always wash before eating, drinking or smoking. Remember that in the case of smoking the heat of the cigarette could change certain chemicals and produce some highly toxic by-products.

Keep work clothing as clean as possible and should any clothing be contaminated it must be removed and laundered before reuse.

Treat skin with respect. Exposures to solvents can result in dermatitis. In addition certain solvents can penetrate skin, even if it is unbroken and thus enter the blood stream with the same effects as inhaling the vapours.

NEVER use solvents to wash hands, a proper hand cleaner followed by soap and water is the best choice – In the case of stubborn contamination use a cloth damped with a not too aggressive solvent – check its Health Hazard Rating first – use only a 3 or a 4.

Dermatitis is an ever-present problem in this industry. A barrier cream should be used on hands. It alone will not give full protection but it will minimise the effect – remember it should be rubbed into the nails – it will be easier to wash out than paint or resin. Proper gloves should be worn – your supervisor and safety officer will ensure that the correct type is issued.

These include moving vehicles and machinery, falling objects and careless practices. A certain amount of common sense and a sense of responsibility in observing factory rules will make life safer for all. Wearing safety gear such as ear protection is your own best interest. Rules, such as those for welding and entry into tanks and confined spaces, requiring specified conditions using a permit and/or lockout system, must be observed.

FLAMMABILITY. Anyone who has had to light a fire must be aware that some substances ignite more easily than others. Coal or charcoal is combustible but to get it to burn means using some method of igniting it. This can be done with paper and wood the paper ignites easily, this gets the wood to burn and this in turn will ignite the coal. Using petrol or spirit on a fire will speed up the initial stage. This is because the spirit/petrol gives off flammable vapours which easily ignite. Some substances can ignite at very low temps and the ease of ignition is termed the flash point. The flash point is the temperature at which the vapours of a substance will ignite if a source of ignition is brought close to its surface. For general purposes we classify substances as follows

There is another category that can be added to the above and that is substances which will not burn but will give off toxic fumes or decompose when heated.

*Note:- The Fire Services consider anything with a flash point <100º to be a “Flammable Substance”

In our industry we must always take precautions to ensure a fire does not start and the low flash substances present the greatest danger. Once the fire starts the flash point becomes irrelevant.

Always assume that highly flammable substances are present and act accordingly. Naked flames or sources of ignition such as smoking must not be allowed in the workplace unless it is zoned as a safe area. Generally the fumes from solvents are heavier than air and so can travel long distances along the ground and especially into drains and sewers. When mixed with air solvent fumes can form explosive mixtures and, should these fumes be ignited, fires so started will travel back to the source of the vapour. The hazards associated with flammable vapours are increased when working at elevated temperatures such as in resin making and when dispersing pigments.

As the types of electrical equipment and fittings are installed in accordance with the risk factor for each factory area, no one should interfere with electrical appliances unless authorised.

Remember – once a fire starts, anything that can burn or decompose on heating will be hazardous!

STATIC If you rub a plastic object such as a comb against a woollen cloth it will start to act as a magnet and will pick up small pieces of paper. This is a form of electric charge and is known as static electricity. Many of the materials we use are capable of acquiring such a charge when poured from one container to another or when stirred and especially when we use a plastic container. These charges can build up to such a level that they cause a spark to earth or to a near object and this can result in the ignition of solvent vapours or dust clouds. Dust from resins is particularly prone to this effect as the resin produces the static and the dust provides the fuel. Solvents, when poured or pumped, are also subject to this phenomenon. It is for that reason that our equipment is earthed and in the case of movable pans and vehicles, including tankers, earth lines are clamped on before any operation takes place. Do not assume that because a substance is non-combustible it will not generate static sparks. If there is any combustible dust or vapour ensure that static lines are secured before pouring. There are exceptions to the rules, but it is always the best policy to take the precautions and use earthing clamps. It is especially wise to take care when using plastic containers, as these are more prone to increase the problem and cannot be earthed. Better to avoid the use of plastic containers if possible but remember this does not make the problem go away completely.

SPONTANEOUS COMBUSTION Many chemical substances when mixed with rags and other combustible substances can start to react and start burning. So be careful with rubbish bins – they must be removed from the work area at night and put in a safe place.

Note – the most frequent causes of fires in the paint industry are static and spontaneous combustion.

METAL POWDERS. Metal powders deserve a special mention. Aluminium and zinc can react with moisture to produce Hydrogen gas which can cause an explosion if ignited. Metal pastes will be flammable so must be treated as such.

NITRO-CELLULOSE. This is a relative of Gun Cotton and is an explosive. Some grades must be stored in designated places and should never be kept in a work area. Follow all instructions when handling these

Due consideration must be given to the handling and disposal of waste. Waste may be liquid, solid or sludge. Firstly always remember that there are two types of drains in a factory – sewers and storm-water. The sewers are intended for contaminated washings conforming to local municipality by-laws and they are not to be used for anything else. Great care must always exercised when disposing of chemicals down drains. Paint factories have special traps installed in order to protect the sewers. Solvents in particular must never be allowed down drains – this can cause an explosion!

Chemical substances must never be allowed to get into a storm-water drain. These often lead into natural watercourses. So, if there is a spill, this should be contained immediately. If an absorbent is not available, use chalk or some other cheap extender. If the spill is a substantial one call your supervisor at once.

One form of waste that must be watched, especially in this country, is the disposal of used packages. Those that have contained highly toxic substances must be cleaned properly or damaged beyond repair so that they cannot be used for domestic purposes.

All components of a formulation must be added in the correct sequences. Deviations can introduce hazards. Do not over-react to a situation. Weigh up the degree of hazard, the conditions under which you are working, the quantity of substance handled and the frequency with which you come into contact with it and then you can decide the levels of precaution needed. If you are unsure – ASK

Your management in general, and your chief executive officer in particular, has a responsibility under the Occupational Health & Safety Act to ensure that proper precautions are taken and he may lay down certain requirements; in which case you have no choice but to accept them.

This publication is intended as a guide and an aid to the implementation of correct health and safety practices in the workplace. The information is given in good faith and every effort has been made to ensure that it is correct. However, neither SAPMA nor SAPITI nor the editors assume any legal liability or responsibility for the accuracy of the information. It is the responsibility of the reader to establish appropriate health and safety practices, and to be aware of and adhere to the provisions of the relevant laws of the country.

Copies of this publication are permitted providing they are done in their entirety and fully, so that the original source is indicated.

SAPMA acknowledges that this booklet is based on material supplied by
L. A. FISHER. Tel 031-2660523
Mail: lesfisher@ecochem.co.za January 2000
Mail: sapma@mweb.co.za