Most trade businesses work with hazardous substances every day. Painters use solvent-based paints and thinners. Gas engineers handle refrigerants and flux. Cleaners work with bleach, descaler and disinfectants. Kitchen fitters use adhesives, sealants and cut MDF regularly. None of this is unusual, but all of it is covered by law.
The Control of Substances Hazardous to Health Regulations 2002 (COSHH) require employers to assess the risks from hazardous substances and put controls in place before workers are exposed to them. If your business uses, stores or generates any substance that could damage health, you need a COSHH risk assessment. There is no exemption for smaller businesses, and the HSE does not scale enforcement against company size.
What COSHH Stands For and What the Regulations Require
COSHH stands for Control of Substances Hazardous to Health. The full name is the Control of Substances Hazardous to Health Regulations 2002 (as amended), enforced by the Health and Safety Executive (HSE) and applicable to virtually all UK workplaces.
A substance is hazardous to health under COSHH if it is:
- Classified as dangerous to health under the Classification, Labelling and Packaging (CLP) Regulation
- A substance assigned a Workplace Exposure Limit (WEL) by the HSE in EH40
- A biological agent
- Dust at a concentration above the general inhalable dust WEL (10 mg/m³) or respirable dust WEL (4 mg/m³)
- Any other substance that creates a comparable risk to health by virtue of its chemical, physical or biological properties
Note that lead, asbestos and radioactive substances are not covered by COSHH; they have their own separate regulations.
Which Businesses Need a COSHH Risk Assessment?
The short answer is: most trade businesses. If any substance your workers handle carries a hazard warning label, comes with a safety data sheet, or is known to cause health effects through inhalation, skin contact or ingestion, you need a COSHH assessment for it.
Here are substances that commonly arise in the trades SafeCompli works with:
- Painters and decorators: Solvent-based paints, primers and thinners containing volatile organic compounds (VOCs). Some two-pack coatings and spray-applied products contain isocyanates, a leading cause of occupational asthma, with a legally required health surveillance programme attached.
- Gas and heating engineers: Refrigerants (many are asphyxiants or irritants at concentration); flux and solder fumes; carbon monoxide in poorly ventilated spaces.
- Kitchen fitters and joiners: Wood dust, classified as a Group 1 carcinogen by the IARC. If you are cutting MDF or hardwood regularly, exposure monitoring and health surveillance are likely required. Contact adhesives and silicone sealants containing acetic acid also need assessment.
- Commercial cleaners: Chlorine-based disinfectants, ammonia-based degreasers, descalers containing phosphoric or hydrochloric acid. Mixing bleach and ammonia-based products creates chloramine gas, a genuine emergency risk that must appear in your COSHH assessment.
- Roofers: Bitumen fumes from hot-applied systems; potential for asbestos disturbance in pre-2000 buildings.
If your response to a strong chemical has ever been to open a window and carry on, that is a COSHH hazard that has not been formally assessed or controlled.
What a COSHH Risk Assessment Must Cover: The 8 Principles
COSHH sets out eight principles that together form any compliant assessment and control regime:
- Assess the risks. Identify the substances in use, how workers are exposed (inhalation, skin contact, ingestion, injection), and what harm they can cause.
- Decide what precautions are needed. Determine controls based on the substance's properties, the quantities used, and the frequency and duration of exposure.
- Prevent or adequately control exposure. Eliminate the substance where possible; substitute with something less hazardous; engineer out the exposure through enclosure or local exhaust ventilation (LEV); or, as a last resort, provide appropriate PPE.
- Ensure that control measures are used and maintained. PPE must be worn in practice, not just provided in theory. LEV systems must be examined and tested at least every 14 months.
- Monitor exposure. Where Workplace Exposure Limits are relevant, measure airborne concentrations and compare against EH40 limits. For some substances, monitoring records must be kept for 40 years.
- Carry out appropriate health surveillance. For specific substances including isocyanates, silica dust and hardwood dust, periodic health checks are a legal requirement.
- Prepare plans and procedures for accidents, incidents and emergencies. What to do in the event of a spill, splash to the eyes or skin, or inhalation incident. First aid measures should align with the safety data sheet.
- Ensure employees are properly informed, trained and supervised. Workers must know what substances they are working with, what the health risks are, and what controls they must use. This must be documented.
How to Use Safety Data Sheets in Your COSHH Assessment
A Safety Data Sheet (SDS) is the document a chemical manufacturer or supplier must provide for any hazardous product. It is your primary reference for completing any COSHH assessment. All SDSs follow a standardised 16-section format under the REACH Regulation:
- Section 2: Hazard identification and CLP classification
- Section 4: First aid measures in the event of exposure
- Section 8: Exposure controls and PPE requirements, including any Workplace Exposure Limit
- Section 7: Handling and storage requirements
- Section 13: Disposal considerations
You are legally required to hold an up-to-date SDS for every hazardous substance in your workplace. Obtain them directly from the manufacturer's website or request them from your supplier. A photocopied sheet from several years ago is not sufficient; formulations change and SDSs are updated, sometimes with significant changes to hazard classifications or control requirements.
When completing your COSHH risk assessment, cross-reference the SDS against the actual conditions of use: the quantity involved, the frequency of use, the ventilation in the space, and the duration of exposure. A substance used briefly outdoors once a week in small quantities carries a very different risk profile from the same substance used indoors for several hours a day.
Common COSHH Failures Found on Inspection
When the HSE inspects trade premises or sites, COSHH deficiencies are among the most frequently cited issues. The failures that come up repeatedly:
- No COSHH assessment at all. Still the most common finding. Many trade businesses assume COSHH applies only to factories and laboratories. It does not.
- Outdated assessments. Written several years ago and never reviewed, even though substances, processes or personnel have changed.
- Safety data sheets not available on site. Workers cannot follow guidance they do not have access to. SDSs should be where the substance is used, not stored in a folder in a back office.
- PPE provided but not used, and no evidence of training. Providing gloves and a respirator and signing a form is not enough. Workers must understand why the PPE is needed and how to use it correctly.
- Missing health surveillance. For isocyanates, hardwood dust and silica dust in particular, health surveillance is a legal requirement and a frequent gap found on inspection.
- No emergency procedures. Workers not knowing what to do in the event of a chemical splash, inhalation incident or major spill.
Each of these is a straightforward gap to close before an inspector finds it.
Ready-Made COSHH Documentation for Your Trade
Writing COSHH risk assessments from scratch is time-consuming, particularly when you are covering multiple substances across different tasks. SafeCompli's trade-specific safety packs include pre-populated COSHH risk assessments for the hazardous substances most commonly used in that trade, already referencing relevant Workplace Exposure Limits, typical exposure routes and standard control measures.
Packs are available for painters and decorators, kitchen fitters, heating engineers, commercial cleaners, roofers and more, each as an instant download in editable DOCX and PDF format at etsy.com/uk/shop/SafeCompli.
For advice on your COSHH obligations, to have your existing documentation reviewed, or for ongoing compliance support, visit www.safecompli.co.uk.