COSHH and Working with Hazardous Substances

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What are hazardous substances?

Hazardous substances are used in many workplaces and take many different forms. Solids, liquids, gases, mists and fumes can be present in the workplace. Exposure to hazardous substances can affect the body in many different ways. Skin contact, inhalation and ingestion can cause damage. In legislation, hazardous substances can be defined in a number of ways. In the Control of Substances Hazardous to Health Regulations 2002 (COSHH) for example they are those substances classified as toxic, very toxic, corrosive harmful or irritant. Biological agents and dusts in substantial concentrations are also classified as hazardous substances.

Why are hazardous substances important?

Hazardous substances can cause short and long term health problems. They can cause serious ill health including cancer, dermatitis and asthma. Employers must control exposure to hazardous substances to preserve the health of their employees.

Who is affected most at risk from hazardous substances?

Anyone who works with or is exposed to hazardous substances is at risk. Those exposed to more hazardous substances for long periods of time are more at risk than those exposed for short periods or to less hazardous substances
The aim should be to prevent exposure to hazardous substances and where exposure cannot be avoided, then adequate controls should be put in place.

Examples of those who could be regularly exposed to hazardous substances include:

  • Cleaners
  • Hairdressers
  • Welders
  • Garage workers
  • Healthcare staff

What does the law say?

All employers have statutory and common-law obligations in relation to the health and safety of their employees and premises.

There are elements of the following legislation that affect hazardous substances:

  • The Control of Substances Hazardous to Health Regulations (COSHH) 2002

Substances hazardous to health are defined under COSHH as those that are: Very Toxic, Toxic, Corrosive, Harmful and Irritant.

  • The Health and Safety at Work etc. Act 1974
  • The Management of Health and Safety at Work Regulations 1999

On 6 April 2005, the regulations were amended, to give a new focus on good practice and help employers meet their duties under the Control of Substances Hazardous to Health Regulations (COSHH).

Good hazardous substances practice

You must assess the risks associated with the hazardous substances present in your workplace. Adequate control of exposure requires employers to:

  • apply the eight principles of good practice for the control of substances hazardous to health (see below)
  • ensure that the Workplace Exposure Limit (WEL) is not exceeded
  • ensure that exposure to substances that can cause occupational asthma; cancer; or damage to genes that can be passed from one generation to another; is reduced as low as is reasonably practicable.

Eight principles of good practice:

  • Design and operate processes and activities to minimise emission, release and spread of substances hazardous to health.
  • Take into account all relevant routes of exposure – inhalation, skin absorption and ingestion – when developing control measures.
  • Control exposure by measures that are proportionate to the health risk.
  • Choose the most effective and reliable control options, which minimise the escape and spread of substances hazardous to health.
  • Where adequate control of exposure cannot be achieved by other means, provide, in combination with other control measures, suitable personal protective equipment.
  • Check and review regularly all elements of control measures for their continuing effectiveness.
  • Inform and train all employees on the hazards and risks from the substances with which they work and the use of control measures developed to minimise the risks.
  • Ensure that the introduction of control measures does not increase the overall risk to health and safety.

More information on hazardous substances