Chemical hazards - H&S at work

The Control of Substances Hazardous to Health Regulations 1999 (COSHH) control the use of chemicals and other substances at work. The HSE has introduced a website called COSHH essentials which give valuable information on this subject.

Hazardous substances include: substances used directly in work activities (eg adhesives, paints, cleaning agents); substances generated during work activities (eg fumes from soldering and welding); naturally occurring substances (eg grain dust). Hazardous substances occur in nearly all work environments.

Examples of the effects of hazardous substances include: skin irritation or dermatitis as a result of skin contact; asthma as a result of developing allergy to substances used at work; losing consciousness as a result of being overcome by toxic fumes; cancer, which may appear long after the exposure to the chemical that caused it; infection from bacteria and other micro-organisms (biological agents).

Assess the risks to health arising from hazardous substances used in or created by workplace activities.

Decide what precautions are needed.
Prevent or adequately control exposure.
Ensure that control measures are used and maintained properly and that safety procedures are followed.
Monitor the exposure of employees to hazardous substances.
Carry out appropriate health surveillance where your assessment has shown this is necessary.
Ensure employees are properly informed, trained and supervised.

The common material that employers should consider are:

Chemicals. For the vast majority of commercial chemicals, the presence (or not) of a warning label will indicate whether COSHH is relevant. Such chemicals may release toxic fumes in use, they may be irritants or cause long term illness.

Common examples of such material are:

The spraying of paints containing isocyanates which cause acute respiratory problems.
The repeated use of bleach by cleaners with no hand protection, causing dermatitis,
The exposure of operators to low levels of vinyl chloride which in time causes bladder cancer.

Flammable substances. A wide variety of flammable materials are use in work places, often the flammable substance is a solvent used as a carrier for other materials (paints, coatings etc). It is important to consider the use and storage of these materials. Problems can arise if they are used in confined areas with poor ventilation (fumes and spray mists can cause explosions or asphyxiation). They should be stored in secure areas that have been properly marked.

Dusts. These commonly arise from a variety of machinery operations, woodworking, milling, grinding etc. If such dusts are permitted to gather into a cloud they can give rise to massive explosions. In addition there is a need for effective local exhaust ventilation to prevent operators exposure.

The following HSE leaflets give guidance upon specific subjects. For specific chemicals see Chemical list indexed opposite.

Chemical Labelling

There are specific regulations for labelling chemical products and labelling vehicles transporting such products. See leaflets indexed below.

Control of Substances Hazardous to Health Regulations (COSHH)

Occupational Exposure Limits Supplement 2003

COSHH Essentials: online assessment tool and guidance sheets

Respiratory Sensitisers and COSHH

Better alarm handling

Biological Monitoring in the Workplace

Chemical reaction hazards and the risk of thermal runaway

Emergency isolation of process plant in the chemical industry

Permit-to-Work Systems