COSHH Regulations for Tradespeople UK — What You Need to Know and Do (2026)

What is COSHH?

COSHH stands for the Control of Substances Hazardous to Health Regulations 2002. Made under the Health and Safety at Work etc. Act 1974, the regulations are enforced by the Health and Safety Executive (HSE) and apply to any business — from a sole trader to a national contractor — that exposes workers or others to substances hazardous to health.

A "substance hazardous to health" is defined broadly: any substance, mixture, or process-generated material that can cause harm by being inhaled, absorbed through the skin, swallowed, or injected. This covers chemical products with hazard labels, but it also covers dusts, fumes, vapours, mists, and biological agents generated during the work itself. If it can damage a person's health, COSHH almost certainly applies.

The regulations do not cover lead or asbestos in their own right — those are dealt with by the Control of Lead at Work Regulations 2002 and the Control of Asbestos Regulations 2012 respectively. However, COSHH does cover incidental asbestos disturbance during minor works (such as drilling through artex), so the overlap matters in practice. Common hazardous substances in trade work include:

• Silica dust (RCS) — generated when cutting masonry, concrete, tiles, and natural stone
• Wood dust — from cutting MDF, hardwood, and softwood
• Asbestos — covered by separate CAWR 2012, but incidental disturbance falls under COSHH
• Lead paint — sanding or burning off old lead-coated surfaces
• Solvents — white spirit, adhesive thinners, primers, strippers
• Cement dust and wet cement — contains hexavalent chromium, a skin sensitiser
• Isocyanates — in two-pack spray paints and spray foam insulation
• Metal fume — from welding, cutting, and brazing ferrous and non-ferrous metals

Which Tradespeople Must Comply?

Any person who uses, produces, or is exposed to hazardous substances in the course of their work is in scope. That includes employers and the self-employed alike. If you employ anyone — even a single apprentice — you are an employer and COSHH applies in full. But sole traders are not exempt: if your work could expose other people (clients, other contractors, passers-by), you have duties under both COSHH and the general duties in the Health and Safety at Work Act.

The trades most commonly encountering COSHH substances include:

• Builders and groundworkers cutting stone, brick, block, and concrete — silica dust
• Tilers cutting porcelain and ceramic tiles — silica dust
• Plasterers mixing and applying gypsum products — gypsum dust and damp conditions
• Decorators using solvent-based paints, strippers, and two-pack coatings — solvents and isocyanates
• Joiners and carpenters cutting MDF, hardwood, and softwood — wood dust and formaldehyde
• Welders and fabricators — metal fume, including manganese in mild steel fume
• Plumbers working in older properties — lead solder, lead pipework, and potential asbestos disturbance

The HSE does inspect sole traders and one-person limited companies. The size of your business does not change the legal duty — it only affects how formal and detailed your records need to be.

The 8-Step COSHH Assessment Process

COSHH does not prescribe a single form or template, but it does require a structured approach. Work through these eight steps for every significant hazardous substance or process.

Step 1 — Identify the substances

Walk through the job and list every substance workers will use or be exposed to. Include products you buy (check the labels for hazard pictograms) and substances generated by the work itself — dust from cutting masonry, fumes from welding, vapours from solvent drying. Don't forget substances already present on site that your work might disturb.

Step 2 — Identify who is exposed and how

Consider the operative directly using the substance, labourers and apprentices working nearby, other contractors on site, and clients or members of the public in adjacent areas. Note the route of exposure — inhalation is most common in trade work, but skin contact (wet cement, epoxy resins) and accidental ingestion (eating without washing hands) also matter.

Step 3 — Evaluate the risk

Compare likely exposure against the Workplace Exposure Limit (WEL) where one exists. Consider the toxicity of the substance, the duration and frequency of exposure, the concentration generated by the task, and the health effects — are they reversible (irritant dermatitis) or permanent (silicosis, lung cancer)? The HSE's COSHH Essentials tool can help estimate exposure levels without full air monitoring in many routine tasks.

Step 4 — Consider substitution

Before reaching for PPE, ask whether you can use a less hazardous alternative. Can you switch from a solvent-based adhesive to a water-based product? Can you use pre-wetted materials to reduce dust? Can you use a different cutting method that generates less airborne silica? Substitution eliminates the hazard at source and is always preferable to controlling residual risk.

Step 5 — Identify control measures

Apply the hierarchy of control in order: elimination, substitution, engineering controls (on-tool extraction, local exhaust ventilation, water suppression), administrative controls (access restrictions, job rotation, safe systems of work), and finally PPE. Document which controls you will use and why PPE alone is not sufficient as a first response.

Step 6 — Implement the controls

Put the controls in place before the work starts. Brief all workers on what the controls are and why they exist. Ensure PPE is correctly fitted and available on site. Check that extraction equipment is working before the first cut.

Step 7 — Monitor effectiveness

Check that controls are actually working. For engineering controls like LEV (local exhaust ventilation), this means formal thorough examination and testing at intervals not exceeding 14 months. For RPE, it means regular fit checks and inspection. Air monitoring may be needed for higher-risk substances to confirm exposure is below WELs.

Step 8 — Review regularly

Review the assessment whenever the work process changes, a new substance is introduced, health surveillance reveals a concern, or there has been an incident. Annual review is a sensible minimum for assessments covering regularly performed tasks. A COSHH assessment is a living document, not a one-off tick-box exercise.

Silica Dust: The Critical Risk for Builders

Respirable crystalline silica (RCS) is the most serious occupational lung hazard for UK construction workers. When you cut, grind, drill, or chase concrete, brick, block, mortar, or natural stone, you generate fine particles of crystalline silica small enough to penetrate deep into the lungs. Over time, this causes silicosis — a progressive, irreversible, and potentially fatal lung disease that causes scarring of the lung tissue. Silica exposure also causes lung cancer. There is no cure for silicosis; the only intervention is preventing further exposure.

The Workplace Exposure Limit (WEL) for respirable crystalline silica is 0.1 mg/m³ as an 8-hour time-weighted average (TWA). This is a very low concentration — typical uncontrolled cutting operations can generate silica dust concentrations 10 to 100 times this limit. You cannot see or smell silica dust at hazardous concentrations.

The required controls for silica dust work are:

• Wet cutting where possible — water suppression reduces airborne dust by over 90% when done properly
• On-tool extraction — an H-class (HEPA-filtered) vacuum connected directly to the angle grinder, disc cutter, or chasing tool
• RPE at minimum FFP3 — a standard disposable dust mask (FFP1 or FFP2) offers no meaningful protection against RCS. FFP3 filtering facepieces or a half-face respirator with P3 filters are required
• Respiratory fit testing for tight-fitting RPE — covered in more detail in the PPE section below

If a worker is later diagnosed with silicosis, this must be reported under RIDDOR (Reporting of Injuries, Diseases and Dangerous Occurrences Regulations 2013) as an occupational disease. Silicosis typically develops years or decades after exposure, which makes prevention critical — you will not see the consequences until it is far too late to undo them.

Wood Dust and MDF

Wood dust is a regulated carcinogen. Hardwood dust is classified as a Group 1 carcinogen by the International Agency for Research on Cancer (IARC) — meaning there is sufficient evidence it causes cancer in humans. Regular exposure to hardwood dust causes nasal cancer (adenocarcinoma of the nasal cavity and paranasal sinuses). Softwood dust is a probable carcinogen and causes asthma and rhinitis.

The WELs are:

• Hardwood dust: 3 mg/m³ (8-hour TWA)
• Softwood dust (and mixed wood dust): 5 mg/m³ (8-hour TWA)

MDF presents a particular risk. As well as wood dust, MDF contains formaldehyde-based urea resin, which is released as fine particles and vapour when the board is cut. Formaldehyde is classified as a known human carcinogen. Cutting MDF in an enclosed space — a workshop, a customer's kitchen, a cupboard — without local exhaust ventilation (LEV) rapidly produces dust concentrations far above the WEL. This is a genuinely serious risk that many joiners and kitchen fitters underestimate.

Required controls for wood dust work include local exhaust ventilation (LEV) at the tool — a correctly specified extraction system attached to the saw, router, or sander — and RPE. For hardwood dust, an FFP3 mask or P3 half-face respirator is the minimum respiratory protection. LEV alone is not always sufficient to keep exposure below the WEL, particularly for high-output tasks such as sanding hardwood floors.

PPE Under COSHH

The COSHH hierarchy of control places PPE last — it is a final layer of protection, not a substitute for engineering controls. Handing a worker a disposable mask and calling it done is not adequate control under the regulations and is one of the most common failures the HSE finds on site.

When PPE is required under COSHH, the correct selection matters:

• FFP2 filtering facepiece — suitable for general nuisance dusts and some lower-hazard operations. Not adequate for silica dust or hardwood dust.
• FFP3 filtering facepiece — required as the minimum for respirable crystalline silica, hardwood dust, and other high-hazard dusts. Single-use disposable; must be discarded when contaminated or at the end of the shift.
• Half-face respirator with P3 filters — reusable; provides better protection than FFP3 disposables for longer-duration or higher-concentration work. Filters must be changed to the manufacturer's schedule.
• Supplied-air or powered air-purifying respirator (PAPR) — for the highest-risk tasks or where tight-fitting RPE cannot be adequately fitted.

Fit testing is a legal requirement for all tight-fitting RPE (FFP3 disposables and half-face respirators). A face-fit test checks whether the particular model of mask creates an adequate seal against the wearer's face. An FFP3 mask that doesn't fit properly offers little more protection than no mask at all. Fit testing must be repeated if the worker's face shape changes significantly (significant weight change, dental work, injury).

Contaminated PPE — gloves, overalls, and disposable masks used around carcinogenic dusts — must be disposed of as controlled waste. Do not shake contaminated clothing in the van or wash it with domestic laundry.

COSHH and Subcontractors

COSHH duties do not stop at your own employees. As a principal contractor or main contractor, you have a duty to ensure that subcontractors working on your site are not exposed to hazardous substances created by your work — and subcontractors have a reciprocal duty not to expose your workers or other contractors to hazards they create.

In practice, this means:

• Sharing COSHH assessments before work starts — subcontractors need to know what hazardous substances are present on site and what controls are in place
• Requiring method statements from subcontractors that cover how they will control hazardous substances they introduce to the site
• Site inductions must cover COSHH substances present on that specific site — a generic induction that makes no mention of the substances actually in use is not adequate
• Monitoring compliance — if you see a subcontractor cutting concrete without extraction in a way that could expose your workers, you have both the right and the duty to stop them

If you are the subcontractor, request the site COSHH information during induction and ensure your own assessment reflects the substances you will encounter on that specific site, not just what you carry in your van.

Record Keeping and Training

COSHH assessments must be written down for significant risks. If you employ five or more people, this is a legal requirement; if you employ fewer, a written record is still strongly advisable as evidence of compliance. Keep assessments for at least five years after they are superseded.

For substances that cause long-latency diseases — silica, asbestos (under COSHH for incidental disturbance), vinyl chloride monomer, and others listed in COSHH Schedule 6 — health surveillance records must be kept for 40 years. Lung cancer and mesothelioma can take 30 to 40 years to develop after exposure, and records may be needed decades later if a former worker makes a compensation claim.

Training records must be kept for all workers who handle or are exposed to hazardous substances. COSHH training does not need to be a formal course — a documented toolbox talk covering the specific substances used on your jobs, their hazards, and the controls you use is sufficient for most trade work. What matters is that workers understand what they are working with and why the controls exist.

Health surveillance is required where workers are regularly exposed to substances with a known link to specific diseases. For most tradespeople, the key triggers are:

• Silica dust — annual lung function tests and respiratory health questionnaires for workers with regular exposure to RCS
• Hardwood dust — lung function and nasal health checks for workers with regular hardwood exposure
• Isocyanates — pre-employment and ongoing respiratory surveillance by an occupational health professional; workers who become sensitised must be removed from further isocyanate exposure
• Dermal sensitisers (wet cement, epoxy resins) — skin health checks for regular users

HSE enforcement for COSHH failures follows the standard route: an improvement notice (requiring you to fix the problem within a set period), a prohibition notice (stopping the activity immediately), or prosecution in serious cases. Prosecution under the Health and Safety at Work Act can result in unlimited fines and, in cases involving gross negligence or death, imprisonment. The HSE publishes details of enforcement actions on its website — COSHH failures feature regularly, particularly around silica dust and asbestos disturbance.