COSHH ACoP L5 and what the 2002 Regulations require at work

The COSHH ACoP is HSE publication L5, Control of substances hazardous to health, available as a free download. The ACoP paragraphs explain how to comply with the COSHH Regulations 2002 and have special legal status. The guidance paragraphs in the same book do not.

The current edition is the sixth, published in 2013. HSE's publication page shows an update date of 7 August 2025, but that is not a new edition. It was approved on 30 October 2013 and took effect on 2 December 2013, replacing the fifth edition, which was withdrawn the same day (L5).

L5 is written for dutyholders and health and safety professionals, with guidance on carcinogens, occupational asthma, monitoring and health surveillance (L5).

What is an ACoP?

ACoP means Approved Code of Practice. HSE approves these codes with the Secretary of State's consent under section 16 of the Health and Safety at Work etc. Act 1974. They give practical guidance on meeting health and safety duties.

Failure to follow an ACoP provision does not of itself make you liable in civil or criminal proceedings (section 17). But in criminal proceedings the code is admissible. If it is proved you did not follow the relevant provision, the breach is taken as proved unless the court is satisfied you complied another way. Following the code is enough to comply on the matters it covers, HSE says.

Guidance isn't compulsory unless it says so, though inspectors may refer to it. Check which kind of paragraph you are reading before you treat a line as an ACoP requirement (HSE legal status).

What are the COSHH Regulations 2002?

The Control of Substances Hazardous to Health Regulations 2002, SI 2002/2677, came into force on 21 November 2002. They set duties for assessing and controlling workplace exposure to substances hazardous to health (the Regulations).

Read L5 alongside the revised legislation. The printed code predates amendments, including the 2015 move from risk phrases to CLP hazard statements, 2018 PPE changes and EU exit amendments.

Under regulation 6, no work liable to expose employees may start until the employer has made a suitable and sufficient assessment. Employers with five or more employees must record the significant findings.

Some employer duties extend, so far as reasonably practicable, to other people affected by the work. Health surveillance does not extend to non-employees. Regulations 10, 12(1) to 12(2) and 13 cover non-employees only if they are on the premises. A relevant self-employed person is treated as both employer and employee, but regulations 10 and 11 do not apply to them (regulation 3).

COSHH regulation 7 and control measures

Regulation 7 requires employers to prevent exposure. Where prevention is not reasonably practicable, exposure must be adequately controlled. Substitution is the preferred way to prevent exposure.

Where exposure can only be controlled, regulation 7(3) sets this order of priority:

1. Suitable work processes, systems and engineering controls, with suitable equipment and materials.
2. Control at source, including adequate ventilation and organisational measures.
3. Suitable personal protective equipment (PPE), where other measures cannot achieve adequate control, and in addition to those measures.

Regulation 7(4) also requires safe handling, storage and transport of substances and waste, suitable maintenance procedures, ventilation and hygiene measures. Employers must minimise the number of people exposed, exposure levels and duration, and the quantity of substance used. Extra controls for carcinogens and mutagens include total enclosure where reasonably practicable, regular cleaning, warning signs and closed, labelled containers. Eating, drinking and smoking are prohibited in areas that may be contaminated by carcinogens or mutagens (regulation 7).

When is control adequate?

Regulation 7(7) says control is adequate only if the eight principles of good practice in Schedule 2A are applied and any workplace exposure limit (WEL) is not exceeded. For substances with hazard statements H340, H350 or H350i, Schedule 1 substances, and asthmagens (H334 or identified as such), exposure must also be reduced to as low as reasonably practicable (regulation 7).

The principles cover minimising emission, release and spread, considering all exposure routes, proportionate controls and choosing the most effective and reliable options. They also require PPE alongside other controls where needed, regular checks, staff information and training, and avoiding increased overall risk. All eight apply, and they are not ranked. Staying below a WEL alone is not enough (L5).

Regulation 8 and employee use of controls

Employers must take all reasonable steps to ensure control measures are properly used. Employees must make full and proper use of them, take all reasonable steps to return them after use to any accommodation provided, and report defects immediately (regulation 8).

Regulation 9 and maintenance of controls

Plant and equipment, including engineering controls and PPE, must be maintained in an efficient state, efficient working order, good repair and clean. Employers must review systems of work and supervision at suitable intervals and revise them where necessary (regulation 9).

Local exhaust ventilation (LEV) needs a thorough examination and test at least once every 14 months. Schedule 4 sets shorter intervals for listed processes: 1 month for blasting of metal castings and for dust or fume from jute cloth manufacture, and 6 months for dry grinding or polishing of metal (more than 12 days a year) and for non-ferrous metal castings. Other engineering controls need examination and testing at suitable intervals (regulation 9; L5, p90).

Reusable respiratory protective equipment must be thoroughly examined and, where appropriate, tested at suitable intervals. Keep examination, test and repair records for at least five years (regulation 9).

Regulation 12 and staff information

Employees who may be exposed need suitable and sufficient information, instruction and training. Regulation 12 requires this to cover:

• the substances, health risks, any WEL, access to safety data sheets and relevant legislation on hazardous properties
• significant findings of the risk assessment
• precautions to protect themselves and others
• exposure monitoring results, with immediate notice if a WEL is exceeded
• anonymised collective health surveillance results
• written instructions where Group 4 biological agents are handled

Other employer and employee responsibilities

Employers must monitor exposure where required, provide health surveillance where required, and plan for emergencies. HSE's COSHH basics overview lists these duties.

Regulation 10 monitoring records that are representative of identifiable employees must be kept for at least 40 years, and other monitoring records for at least five years. Regulation 11 health records must be kept for at least 40 years from the last entry (L5, pp49 and 54).

Employees must attend required health surveillance in working hours, at the employer's cost. They must give the relevant doctor health information reasonably required (regulation 11(8)). They must immediately report incidents that may have released biological agents capable of causing severe human disease (regulation 13(5)).

General duties also apply under the 1974 Act. Employees must take reasonable care, co-operate with their employer, and not interfere with or misuse anything provided for health and safety (sections 7 and 8).

Does COSHH cover asbestos and lead?

Mostly not. HSE says lead, asbestos and radioactive substances have their own specific regulations (HSE overview), but the legal carve-out has limits.

Regulations 6 to 13 do not apply "where and to the extent that" the Control of Lead at Work Regulations 2002 or the Control of Asbestos Regulations 2012 apply. Regulations 6 to 13 can still apply to lead or asbestos exposure that those specific regulations do not cover (regulation 5).

The 2013 text of regulation 5 also lists a coal-mine dust exclusion. That item was revoked from 6 April 2015, so it is not a current carve-out (regulation 5).

Regulation 5 also excludes regulations 6 to 13 where the hazard arises solely from radioactivity, explosiveness, flammability, high or low temperature, or high pressure. The exclusion for medical treatment concerns the risk to the person receiving the substance, not all workplace handling of medicines (regulation 5).

For a shorter introduction, HSE's free INDG136 leaflet covers the basics. COSHH essentials gives control advice for common tasks. RegAffairs AI's COSHH ACoP answer links its explanations to the source text.