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Posted on: 09 January 2019
Refer to the Control of Substances Hazardous to Health Regulations 2002 and subsequent 2004 amendment regulations on legislation.gov.uk

The Control of Substances Hazardous to Health (COSHH) Regulations have been in existence since 1988, though there have been a number of re-enactments and amendment regulations since then to reflect developments in hazardous substance risks and controls and to incorporate European Directives into UK domestic law.

The main aims of the COSHH Regulations is to protect people from the hazards of substances used or likely to be present in the workplace and to impose specific duties regarding the import and use of certain specified substances within the EU.

The Regulations apply to a wide range of substances and preparations (mixtures of two or more substances) which have the potential to cause harm to health if they are ingested, inhaled, absorbed by, or come into contact with, the skin, or other body membranes. Hazardous substances can occur in many forms, including solids, liquids, vapours, gases and fumes.

For clarity, the term “substances” may relate to products that are bought in or used as part of a process, in addition to any substances generated during a process (by-products) that may be hazardous to health. Hazardous substances include:

  • chemicals;
  • products containing chemicals;
  • fumes;
  • dusts;
  • vapours;
  • mists;
  • nanotechnology;
  • gases and asphyxiating gases;
  • biological agents; and
  • pathogenic germs.
The COSHH Regulations do not cover asbestos, lead or radioactive substances, all of which are the subject of specific legislative articles.

The COSHH Regulations impose duties on employers to safeguard the health and safety of employees and others (such as contractors and visitors) that may be affected by hazardous substances within the workplace through a combination of risk assessment, exposure control, monitoring, health surveillance and incident planning.

It must also be recognised that the employee also has a responsibility to co-operate with their employer and take steps to protect themselves from the health hazards presented by substances they work with or around. For the purpose of these Regulations, a self-employed person carries the responsibility of both the employer and employee.

While the duties of the employer extend to persons not in his employment, the requirements for provision of health surveillance, monitoring, instruction and accident response training (Regulations 10, 11, 12 and 13) don’t normally extend to non-employees. It’s also important to note that Regulations 6 to 13 don’t apply where the risk is to the health of a person who is being administered with a hazardous substance in the course of medical treatment (e.g. chemotherapy).

Employers must not carry out work, or allow work to be carried out, which could potentially expose people to hazardous substances unless a suitable and sufficient health and safety risk assessment has been carried out and recorded. A significant part of the assessment should involve ensuring that the necessary control measures have been identified and implemented.

Whoever carries out the assessment must be competent for the task and provided with information on the prevention and control measures. They should:

  • know how the work activity uses, produces or creates substances hazardous to health;
  • have the knowledge, skills, training and experience to make sound decisions about the level of risk and the measures needed for prevention or adequate control of exposure; and
  • have the ability and the authority of the employer to collate all the necessary, relevant information.

Once the risk assessment has been carried out, the necessary actions must be implemented to:

  • prevent or adequately control exposure;
  • ensure control measures are maintained, examined as tested as required;
  • provide exposure monitoring and health surveillance where identified as necessary and  information and instruction are provided and training is carried out; and
  • deal with accidents, incidents and emergencies.

All employers must carry out a risk assessment but those employing five or more employees need to also record any significant findings.

The risk assessment must be regularly reviewed and immediately whenever there is evidence that it’s no longer valid, with consideration given to:

“a. the hazardous properties of the substance;

b. information on health effects provided by the supplier, including information contained in any relevant safety data sheet;

c. the level, type and duration of exposure;

d. the circumstances of the work, including the amount of the substance involved;

e. activities, such as maintenance, where there is the potential for a high level of exposure;

f. any relevant occupational exposure standard, maximum exposure limit or similar occupational exposure limit;

g. the effect of preventive and control measures which have been or will be taken in accordance with regulation 7;

h. the results of relevant health surveillance;

i. the results of monitoring of exposure in accordance with regulation 10;

j. in circumstances where the work will involve exposure to more than one substance hazardous to health, the risk presented by exposure to such substances in combination;

k. the approved classification of any biological agent; and

l. such additional information as the employer may need in order to complete the risk assessment.”

Regulation 6(2) (Assessment of the risk to health created by work involving hazardous substances to health), The Control of Substances Hazardous to Health Regulations 2002, legislation.gov.uk

After identifying that a substance is, or has the potential to be, hazardous, employers must first make attempts to prevent exposure by eliminating it from the workplace or by substituting it for a less hazardous substance. Only after it has been determined that it’s not reasonably practicable to prevent exposure to a hazardous substance should control measures be investigated and implemented.

Adequate control is to be achieved by, in order of priority, looking at the:

  • design of work processes, systems and engineering controls, including the work equipment and materials involved;
  • management of exposure at the source (e.g. by installing suitable ventilation or organisational arrangements, such as prohibiting entry to areas for certain periods of time to allow gases produced by processes to be dispelled); and
  • as a last resort, the provision of appropriate personal protective equipment (PPE).

For each of these measures there needs to be arrangements for:

  • safe handling, use and storage of hazardous substances or waste containing such substances;
  • suitable maintenance procedures;
  • restricting the number of persons that may be exposed, the level and duration of exposure and the amount of the substance present in the workplace;
  • controlling the workplace environment (i.e. ventilation, as well as matters such as lighting and housekeeping); and
  • suitable hygiene facilities, e.g. handwashing basins and showers.

Good practice in the control of substances hazardous to health is encapsulated in the eight generic principles of good practice set out in Schedule 2A of the Regulations.

Employers have a duty to take all reasonable steps to ensure that the control measures provided are properly applied and maintained, while employees are to make full and proper use of any control measure and report any defects or shortfalls to the employer.

Maintenance needs to carried out so that equipment and installations are kept clean and in efficient working order; in the case of engineering controls this includes the thorough examination of local exhaust ventilation (LEV) at least every 14 months, unless more frequent examination is specified in Schedule 4, and of other control measures (such as reusable respiratory protective equipment (RPE)) at suitable intervals. Records of these examinations must be maintained for at least five years.

Similarly, any personal protective equipment (PPE) needs to be properly stored, regularly checked/inspected and repaired or replaced before further use if defective. Any equipment that may be contaminated must be decontaminated, safely disposed of or destroyed as appropriate.

Additional requirements:

Where the hazardous substance involved is a carcinogen (a substance capable of causing cancer) the measures outlined above must be supplemented by the following extra actions:

  • where reasonably practicable, totally enclose the activity and handling systems;
  • ban smoking, eating or drinking in areas that may be contaminated by carcinogens;
  • clean walls and surfaces on a regular basis;
  • designate areas which may be contaminated and identify them with warning signs and markings; and
  • store, handle and dispose of carcinogens safely using enclosed and labelled containers.

Similarly, if work involves the use of a biological agent (a substance that can cause injury, illness, disablement or death and that could be weaponised) these additional measures need to be put in place:

  • display appropriate warning signs, including the prescribed biohazard sign;
  • provide instruction for decontamination and disinfection procedures;
  • ensure that there are provisions so that contaminated waste is correctly stored and disposed of;
  • test other areas to make sure they do not become contaminated;
  • have formal procedures for the handling, use or storage of biological agents;
  • provide any available vaccinations for employees who may be exposed;
  • make appropriate hygiene arrangements and prohibit eating, drinking and smoking in areas where there is a risk from a biological agent, to prevent cross-contamination; and
  • quarantine any person or animal that may be infected to prevent the spread of disease.

The Health and Safety Executive (HSE) has established WELs for a number of substances hazardous to health (see EH40/2005 Workplace exposure limits). These are intended to prevent excessive exposure to specified hazardous substances by containing exposure below a set limit. A WEL is the maximum concentration of an airborne substance averaged over a reference period to which employees may be exposed by inhalation.

Where a maximum exposure limit is specified, the employer has a duty to ensure that the specified limit is not exceeded and to control exposure as low as reasonably practicable below that limit. For other specified occupational exposure levels, the employer should ensure that the specified exposure level is not exceeded or, where it is exceeded that the cause of excursion is identified and the exposure level reduced to below the specified level without delay.

Unless it can be demonstrated that contact has been prevented or adequately controlled, employers must use a suitable methodology to monitor their employees’ exposure to hazardous substances. Where there is a substance/process specified in Schedule 6 or a reasonable likelihood that an identifiable disease or health condition might arise from exposure, affected employees must be enrolled in a suitable health surveillance programme (so long as there valid techniques for identifying the indications of the disease or effect).

Monitoring needs to be carried out on a regular basis (for substances or processes listed in Schedule 5 there is a specified minimum frequency) and records kept for a minimum of 40 years from last entry for personal monitoring and 5 years from last entry for other monitoring.

Health surveillance should be conducted under the supervision of a relevant doctor at least annually. If a relevant doctor decides that an employee should be excluded from continued exposure to a substance/process or conditions, the employer must comply with this advice.

Employees are required to co-operate with their employer regarding health surveillance, attend associated appointments (arranged during working hours at the employer’s instruction and expense) and, where this relates to substance/process specified in Schedule 6, shall give all reasonably required relevant information about his/her health to the relevant doctor.

Employees that are subject to health surveillance must be allowed access to his/her personal monitoring record and copies of those records must be provided by the employer to the Health & Safety Executive (HSE) where required. The HSE should be notified immediately if the organisation ceases to trade and all monitoring records available to them.

If it’s discovered that an employee has an identifiable disease or adverse health effect as a result of exposure to hazardous substance then their employer must:

“(a) ensure that a suitably qualified person informs the employee accordingly and provides the employee with information and advice regarding further health surveillance;

(b) review the risk assessment;

(c) review any measure taken to comply with regulation 7, taking into account any advice given by a relevant doctor, occupational health professional or by the Executive;

(d) consider assigning the employee to alternative work where there is no risk of further exposure to that substance, taking into account any advice given by a relevant doctor or occupational health professional; and

(e) provide for a review of the health of any other employee who has been similarly exposed, including a medical examination where such an examination is recommended by a relevant doctor, occupational health professional or by the Executive.

Regulation 11(9) (Health surveillance), The Control of Substances Hazardous to Health Regulations 2002, legislation.gov.uk

The employer must allow the relevant doctor to carry out an inspection of the workplace/activity if they feel that this is necessary. Any appeal (by the employer or the employee) against the recommendation of a relevant doctor to suspend an employee from work activities or to impose conditions upon such work should be made in writing to the HSE within 28 days of receiving the recommendation.

Any employer who has employees carrying out work that exposes them to hazardous substances is required to provide such employees with suitable and sufficient information, instruction and training that includes:


  • details of the substance(s), including exposure limits and any relevant safety data sheet;
  • risk assessment conclusions;
  • the measures in place and to be taken to protect their self and others;
  • the results of any exposure monitoring that has been carried out, including comparison of results with any listed exposure limits or standards;
  • anonymised collective results of any health surveillance; and
  • (where the exposure is to a biological agent or material that may contain such an agent) written instructions and, if appropriate, posters or similar reminding employees what actions to take when handling such an agent or material.

The information, instruction and training shall be reviewed and revised as appropriate to ensure that it remains valid and is presented in a manner that is proportionate to the level, type and duration of exposure.

The requirement for the employer to provide suitable and sufficient information, instruction and training shall extend to individuals carrying out the work whether or not they are his employees (i.e. contractors).

Any container or pipe used to contain a hazardous substance should be suitably labelled so as to identify its contents and any associated hazards.

Emergency arrangements are to be prepared to protect employee health in the event of an accident/incident involving substances which are hazardous to health. These arrangements should include first aid provision, safety drills (which should be practised regularly), relevant information, suitable alarms and, if appropriate, rescue procedures.

The accident/emergency arrangements should include information for emergency services and should also be displayed within the workplace as appropriate.

In the event of an accident/emergency involving a substance hazardous to health, so long as the risk involved is low and adequately controlled, the employer is required to take immediate steps to manage the effects of the accident, restore normal order and inform all affected employees.

During repairs and other necessary work, only essential workers equipped with suitable PPE and specialised safety equipment/plant should be permitted entry to the affected area.

In the case of an incident involving a biological substance with the potential to cause serious disease, the employer must inform his employees as soon as practicable of the cause of the incident and the measures taken or to be taken to restore the situation.

If there is an incident which has or may have resulted in the release of a biological agent that could cause serious human disease, employees must report it to the employer (or any other person with responsibility for ensuring the health and safety of employees) without delay.

Refer to the various Schedules within the COSHH Regulations for detailed requirements and application.
When considering issues relating to COSHH, you may also need to consider the following legislation:

The implementation of the CLP Regulations harmonised standards throughout the EU for chemical classification, containment requirements for storage and transportation and common identification/warning labels.

Effective from 1 June 2015, these Regulations repealed and replaced the Chemical Hazard Information and Packaging (CHIP) Regulations.