Comply with COSHH regulations for hazardous substances

What COSHH requires you to do

The Control of Substances Hazardous to Health Regulations 2002 (COSHH) require employers to prevent or adequately control employee exposure to hazardous substances in the workplace.

COSHH applies to most businesses, not just those in obviously hazardous industries. If your employees use cleaning products, paints, adhesives, solvents, or work in environments with dust, fumes or biological agents, COSHH applies to you.

When COSHH applies to your business

COSHH covers substances that can cause harm to health, including:

• chemicals such as cleaning products, solvents, paints, adhesives, pesticides and disinfectants
• dusts such as wood, flour, silica and metal dusts
• fumes from welding, soldering and exhausts
• vapours from solvents, fuels or heated processes
• mists such as oil mists, paint sprays and coolant mists
• gases such as carbon monoxide, chlorine and ammonia
• biological agents such as bacteria, viruses and fungi, including Legionella and bloodborne pathogens
• engineered nanoparticles

COSHH does NOT cover:

• Asbestos (separate Control of Asbestos Regulations 2012)
• Lead (Control of Lead at Work Regulations 2002)
• Radioactive materials (Ionising Radiations Regulations 2017)

These substances have their own specific regulations with additional requirements.

Your COSHH duties, step by step

Regulations 6 to 13 of COSHH set out your duties as an employer. Work through them in this order:

The hierarchy of controls (ERICPD)

COSHH requires you to apply controls in a specific order of priority. You must always consider measures higher up the hierarchy before moving to lower levels:

1. Eliminate: remove the hazardous substance entirely by using a non-hazardous process or stopping the activity.
2. Reduce or substitute: replace it with a less hazardous substance, such as a water-based instead of a solvent-based product.
3. Isolate: enclose the process so workers are separated from the hazard, for example with fume cupboards or glove boxes.
4. Control: use local exhaust ventilation (LEV), general ventilation or other engineering controls to reduce exposure.
5. PPE: respirators, gloves and goggles, used only as a last resort or combined with other measures.
6. Discipline: safe systems of work, procedures, training, supervision, signage and reduced exposure time.

PPE should never be your first choice. It is the last line of defence, not the first. If you rely solely on PPE, HSE will question whether you have adequately considered higher-level controls.

In practice, most effective COSHH control involves a combination of measures, for example substituting a less hazardous substance, using LEV, and providing PPE for additional protection.

Workplace Exposure Limits (WELs) and EH40

Workplace Exposure Limits are the maximum concentrations of hazardous substances that can be present in workplace air, averaged over a reference period. They are legally binding limits that must not be exceeded.

WELs are published in HSE document EH40, which lists over 500 substances. You must check EH40 for any substance your employees are exposed to. Exceeding a WEL is a breach of COSHH Regulation 7.

WELs are maximum permitted concentrations, not safe levels. You must reduce exposure as low as is reasonably practicable, even if below the WEL. Some substances (carcinogens, mutagens, asthmagens) have no truly safe level - any exposure carries risk.

For substances without a WEL, you must still control exposure to a level that protects health, using industry guidance and good practice.

Health surveillance requirements

Health surveillance is the medical monitoring of employees to detect early signs of work-related ill health. Under COSHH Regulation 11, you must provide health surveillance where:

• Employees are exposed to substances linked to identifiable diseases or adverse health effects
• There is a reasonable likelihood that the disease or effect will occur under the conditions of work
• There are valid techniques to detect the disease or effect

Health surveillance record keeping

Each individual health record must show the employee's name, date of birth and employment history, and the dates and conclusions of their health surveillance. COSHH sets strict retention periods:

The period is long because some occupational diseases (e.g. mesothelioma, occupational cancers) have latency periods of 20-50 years. Records may be needed decades later to establish exposure history for compensation claims or epidemiological studies.

Information, instruction and training

Regulation 12 requires you to provide employees with suitable and sufficient information, instruction and training about:

• the hazardous substances they work with and their health effects
• the risks created by exposure and what affects them (duration, concentration, route)
• the control measures in place and why they matter
• how to use controls properly, including PPE, LEV and safe handling procedures
• the results of exposure monitoring, where relevant to their work
• the results of health surveillance, with appropriate confidentiality
• emergency procedures for a spill, leak or exposure incident

Provide training before employees start working with hazardous substances, when work processes change, when new substances are introduced, and at regular intervals as a refresher.

Safety data sheets

A safety data sheet is your main source of information for a COSHH assessment, which must take account of it. Your supplier must give you one, free of charge on paper or electronically, no later than the first delivery of any substance or mixture classified as hazardous. They must also give you one on request for some unclassified mixtures, including those containing a substance with a workplace exposure limit, and send you a revised, dated version when new hazard information becomes available.

The sheet must be in English and dated, and it follows 16 headings:

• identification of the substance or mixture and the supplier
• hazards identification
• composition and information on ingredients
• first-aid measures
• fire-fighting measures
• accidental release measures
• handling and storage
• exposure controls and personal protection
• physical and chemical properties
• stability and reactivity
• toxicological information
• ecological information
• disposal considerations
• transport information
• regulatory information
• other information

Ask for a sheet if one is missing, keep the latest version, and let employees and their representatives see the sheets for the substances they use or may be exposed to. Products sold to the public often come without a sheet; ask the supplier for one if you use them at work.

COSHH Essentials - HSE's free tool

HSE provides a free online tool called COSHH Essentials that helps small businesses identify appropriate control measures. You answer questions about the substance (hazard classification) and the task (amount used, dustiness/volatility), and the tool recommends control approaches.

COSHH Essentials is a good starting point for common substances and straightforward tasks. For complex situations, unusual substances, or where WELs are involved, you may need more detailed assessment.

Common COSHH compliance failures

HSE inspectors frequently identify these failings:

• no COSHH assessment, or one that is generic, out of date or not task-specific
• relying on PPE such as respirators when LEV would be more effective
• LEV that is not maintained or tested, so extraction does not work properly
• no exposure monitoring when the assessment cannot show controls are adequate
• employees who do not understand the risks or how to use controls
• poor housekeeping: contaminated surfaces, inadequate cleaning and dust build-up
• no health surveillance when the exposure requires it
• missing or incomplete records