Control of Substances Hazardous to Health Regulations ‘COSHH’

The regulations have been amended by the “Control of Substances Hazardous to Health (Amendment) Regulations 2004”, the definitions for exposures have been altered from OES and MEL to read “workplace exposure limit” (WEL).

The “workplace exposure limit” is for a substances hazardous to health means the exposure limit approved by the Health and Safety Commission for that substance in relation to the specified reference period when calculated by a method approved by the Health and Safety Commission, as contained in the HSE publication “EH40 workplace Exposure Limits 2005” as updated from time to time.

Where there is exposure to substance hazardous to health, control of that exposure shall only be treated as adequate if –

  • The principles of good practice for the control of exposure to substances hazardous to health set out in the schedules are applied,
  • Any workplace exposure limit approved for that substances is not exceeded, and
  • For a substance which carries the risk phrase R45, R46 or R49 or for a substance or process which is listed in schedule 1 or which carries the risk phrase R42 or R42 / R43 of which is listed in Section C of HSE publication “Asthmagen? Critical assessments pf the evidence for agents implicated in occupational asthma” as updated from time to time.
R42 May cause sensitisation by inhalation
R42/43 May cause sensitisation by inhalation and skin contact
R45 May cause cancer
R46 May cause heritable genetic damage
R49 May cause cancer by inhalation

There are other amendments to the regulations and this should not be read and taken as a complete update.

The requirements of the regulations are listed below: –

Regulation 6 – assessment of health risks created by working with hazardous substances.
Regulation 7 – prevention or control of exposure to substances hazardous to health.
Regulation 8 – use of control measures.
Regulation 9 – maintenance, examination and test if control measures.
Regulation 10 – monitoring of the exposure at the workplace.
Regulation 11 – health surveillance
Regulation 12 – provision of information, instruction and training.

We can complete assessment of health risks created by working with hazardous substances.

General Information.

Failure to comply with the COSHH regulations can lead to legal prosecutions under the “Health and Safety at Work Etc Act 1974” and is subject to penalties under the act and can lead to civil claims.

It aims to establish suitable levels to which all employers and employees must work by using basic principles of Occupational Hygiene such as identification, evaluation and control. The COSHH regulations lay down the essential requirements along with stepped hierarchical approach for the control of substances and for the protection of persons who may be exposed to those substances. In effect they require employers to plan, manage and monitor the use of chemical, micro-organisms and other substances hazardous to health.

Substances hazardous to health have been defined as “all substances that have the potential for causing harm to person’s health”. A substance that is hazardous is not just a single chemical substance or compound, it includes mixtures of these compounds, micro-organisms, allergens or the synergistic effects between them.

The COSHH regulations apply to all substances that may already have been classified as being in the very toxic, harmful, corrosive or irritant under the “Chemical (Hazard Information and Packaging for Supply)(Amendment) Regulations)”.

Biological agents capable of causing infection, allergy, toxicity or other human health hazards, in the form of dust at a substantial concentration in air. Not listed in the category above, but which can create a health hazard comparable to any of them.

These factors are defined as hazardous to health, but additional factors need to be taken into account. Such as different forms of the substance may present different hazards. Many substances contain impurities that could present greater hazards than the substance they contaminate. Some substances have a fibrous form which may present a potentially serious hazard to health if the fibres are of a certain shape and size. Combined or sequential exposure to various substances may have an addictive or synergistic effect.

Excluded from these regulations are asbestos, lead, materials producing ionising radiation’s and below ground in mines. These have their own legislation and regulations that would govern their exposure.


The COSHH regulations require that no work, which is liable to expose persons to substances hazardous to health, shall be carried out unless an assessment has been made. An assessment can be defined as “an evaluation of the risks to health and then deciding on the required action to remove or reduce those risks”.

Every employer is required to carry out an assessment of the risks to health created by any activity likely to expose employees to any substance hazardous to health. The purpose of the assessment is to enable a valid decision to be made about measures necessary to control substances hazardous to health arising out of or in the course of work.

suitable and sufficient assessment should include: –

  • An assessment on the risks to health.
  • Steps required which need to be taken to achieve adequate control of exposure.
  • Identification of other action necessary to ensure control.

How far you have to go with control measures, monitoring, health surveillance will depend on the results of the assessment. A number of tasks must be included within the assessment.

  1. Assembling information about the substance.
  2. The work and working practices and procedures.
  3. How the substances are used.
  4. Evaluating the risk to health.
  5. Deciding what other further precautions are needed to comply with the regulations.
  6. Recording the assessment, unless the risks are so low that it is unnecessary to record them.
  7. Reviewing and revising the assessment when changes take place i.e. work practices and procedures, how the substances are used.

The following is an aid to assessing what may be required to complete the assessment process to meet the whole of the COSHH regulations.

Risks insignificant now and it is not reasonably foreseeable that they could increase in the future. Finish assessment now. No precautions necessary for the purpose of COSHHR.But review assessment if circumstances should change or alter.
Risks high now and not adequately. Identify and implement immediate interim measures for preventing or controlling exposure. Even consider stopping the process. Assess longer-term control requirements.
Risks are controlled now, but could reasonably become higher in the future. Determine precautions to maintain control and minimise chances of higher exposure occurring. Decide additional measures for regaining control in case high-risk event does occur, despite precautions.
Uncertain about risks. Nature of hazard where known, but uncertain about degree of criteria i.e. extent of hazard. Measure and compare exposure and possible and/or use other standards of good practice. Obtain specialist advice if necessary.Determine what, if anything has to be done about improving control or exposure.Decide what arrangements are needed to sustain control.
Cannot decide about risk, not enough information. Find out more as necessary and/or seek advice or help until it is possible to arrive at conclusion.Meanwhile apply principles of good occupational hygiene to minimise exposure.

The following hierarchy of control measures available is to prevent exposure to substances hazardous to health.

  • Substitution with less toxic substance.
  • Isolation or enclosure of process.
  • Local exhaust ventilation.
  • General ventilation.
  • Personal protective equipment (PPE).
  • Controlled exposure.
  • Hygiene measures.

Although substitution with a harmless or less hazardous substance is the ideal option, in practice engineering controls or personal protective equipment are the measure most widely used and employed.

Local exhaust or extract ventilation is the standard control measure for dealing with dusts, vapours and fumes that are generated from a source point.

All control measures should be properly maintained and regular checks should be made to ensure they continue to work or operate as intended, so that prevention or adequate control of exposure is sustained.

Where local exhaust prevention is provided it shall be thoroughly examined and tested at least every fourteen months.

Personal Protective Equipment (PPE) is the last line of defence against substances hazardous to health. It is unacceptable to require employees to be encumbered by PE when the process itself could or should be enclosed, or the hazardous substances could be eliminated by substitution.

Other methods to control exposure are to: –

  • Stop using the substance.
  • Use the same substance in less hazardous form.
  • Prevent or minimise the extent to which dusts, gases, vapours and fumes are given off.
  • Limit the area of contamination.
  • Restrict the numbers of employees exposed.
  • Introduce regular cleaning.
  • Provide safe means of storage and disposal of substances.
  • Prohibit eating, smoking or drinking in the locality.
  • Provide adequate welfare facilities and washing and changing areas.
  • Set up and control system to ensure that clothing and equipment are properly used and maintained.

The control methods are not restricted to inhalation (breathing), but must also be able to tackle ingestion (through mouth), through skin absorption and general contact where these routes of entry into the body are potentially harmful.

Control measure employed shall also include for any contingency plans for emergencies such as spillages.

Maintenance of Controls.

All control measures that are provided to meet the requirements of the regulations must be maintained to ensure that they continue to be effective in preventing or adequately controlling exposure of employees to substances hazardous to health.

The term “maintenance” covers any work completed to sustain the efficiency of control measures not just carried out by maintenance personnel. It includes visual checks, inspections, and testing, servicing and remedial works.

For some examinations, such as local exhaust ventilation, a detailed specification is provided within the code of practice, for other areas only the outline is indicated.

The operation and use is also effected by the need to protect adjacent work areas and the possible release of harmful emissions into the environment.


Monitoring means the use of valid occupational hygiene techniques to conclude a quantitative judgement of the exposure of employees to substances hazardous to health.

When monitoring is required it should be completed at least every twelve months, except where frequencies are stated in the relevant schedules of the regulations.

Monitoring strategies are required to maintain adequate controls, protect the workforce health and at the assessment stage, to establish the extent to which potentially hazardous substances represent a risk to health.

Airborne contaminants involve the periodic use or continuous sampling of the atmosphere at the workplace and will sometimes require sampling in the breathing zone by the use and means of personal sampling equipment.

The “Health and Safety Executive” (HSE) document EH42 provides useful advice on the principles of monitoring. This should be used with the HSE guidance note EH40 that deals with occupational exposure standards.

Health Surveillance.

The aims of health surveillance where employees are exposed to substances hazardous to health in the course of their work are:-

  • The protection of the health of the individual employees by the use of detection as soon as possible, of any adverse changes which may be attributed to exposure to substances hazardous to health.
  • The collection, maintenance and the use of date for the detection and evaluation of hazards to health.
  • To assess, in relation to specific work activities involving micro-organisms hazardous to health, the immunological status of employees.

Health surveillance includes the keeping of individual health records and setting up of procedures for monitoring employee health.

  • Biological monitoring, the measurements and assessment of workplace agents and the metabolites.
  • Biological affect monitoring, the measurement and assessment of early biological effects in exposed workers.
  • Medical surveillance, clinical examinations and measurements of physiological and psychological effects of exposure to hazardous substances in the workplace, as indicated by alterations in body function or constituents.
  • Enquiries about symptoms, inspections or examinations by a suitably qualified person.
  • Inspection by a responsible person.
  • Review of records and occupational history during and after exposure, to check correctness of the assessment or risks to health and to indicate if the assessment requires reviewing.

For certain substances and processes which may give rise to identifiable adverse health effects, the health surveillance measures must be carried out. These records must be kept for at least forty years. Information, Instruction and Training.Every employer undertaking work which may expose any employees to substances hazardous to health has a duty to ensure those employees are provided with such information, instruction and training as is suitable and sufficient for them to know about the hazards and risks to health. It should include, but is not necessarily limited to the following:-

  • The risks to health created by exposure.
  • The precautions that need to be taken.
  • Instructions and training on how to use and maintain control measures.
  • Information on any environmental monitoring and health surveillance conducted and completed.
  • Emergency procedures.

It is also the responsibility of the employer to ensure that any persons carrying out work in connection with the employer’s duties under COSHH, such as ventilation contractors, environmental advisers/consultants, medical staff and other non-employees have such information, instruction and training as is necessary for them to complete their work task safely and effectively.


Tuesday, June 9th, 2009 services