COSHH Regulations for Trade Businesses UK — Hazardous Substances Guide (2026)

What COSHH Is

The Control of Substances Hazardous to Health Regulations 2002 (COSHH) are made under the Health and Safety at Work etc. Act 1974 and enforced by the Health and Safety Executive (HSE). They apply to any work that involves substances — whether purchased products or materials generated by the work process — capable of causing ill health by inhalation, skin absorption, ingestion, or injection.

"Hazardous to health" is defined broadly. It includes:

• Chemicals and preparations carrying hazard warning labels (GHS pictograms)
• Dusts generated in substantial concentrations during cutting, grinding, or sanding
• Fumes produced by welding, brazing, soldering, or burning
• Vapours from solvents, adhesives, paints, and strippers
• Biological agents such as Weil's disease (leptospirosis) in drainage and groundwork
• Skin and eye irritants including wet cement, epoxy resins, and fibreglass insulation

COSHH does not cover lead or asbestos as standalone subjects — those are governed by the Control of Lead at Work Regulations 2002 (CLAW) and the Control of Asbestos Regulations 2012 (CAR) respectively. However, COSHH does apply to incidental asbestos disturbance during minor non-licensable work, so the boundaries matter in practice.

COSHH applies to any employer and to self-employed persons whose work could expose other people to hazardous substances. Running as a sole trader does not exempt you from the duty; the size of the business affects only the level of formal documentation required, not the underlying legal obligations.

Substances Trades Commonly Encounter

The specific COSHH risks vary by trade. These are the substances most likely to arise in day-to-day work:

• Painters and decorators — solvent-based paints and varnishes (aromatic and aliphatic hydrocarbons), isocyanate hardeners in two-pack polyurethane coatings (risk of occupational asthma and sensitisation), paint strippers containing dichloromethane or caustic alkalis
• Plumbers — soldering flux fumes (flux paste releases rosin and activator vapours when heated), jointing compounds containing PTFE and solvents, lead solder residues in older properties
• Electricians — cable pulling lubricants, fibreglass insulation dust when working in loft spaces, solvents in cable jackets during heat shrinking
• Builders and groundworkers — cement dust and wet cement (contains hexavalent chromium, a known skin sensitiser causing chrome ulcers and dermatitis), respirable crystalline silica (RCS) from cutting concrete, blocks, and paving, wood dust from cutting MDF and timber, lead paint in properties built before 1980
• Roofers — bitumen fumes when applying hot-applied or torched felt systems (bitumen fume is a possible carcinogen and causes skin and eye irritation), fibreglass insulation dust when fitting Rockwool or mineral wool between rafters

Safety Data Sheets (SDS)

For any hazardous substance supplied to your business, the supplier is legally required to provide a Safety Data Sheet (SDS). An SDS is a 16-section technical document that describes the hazards, safe handling requirements, exposure controls, and disposal method for the product.

Where to find SDS documents:

• Printed on or included with the product packaging
• The manufacturer's or supplier's website — most major trade suppliers maintain a searchable SDS library
• Ask your merchant or distributor — they are obligated to provide them

The sections most relevant to a COSHH assessment are:

• Section 2 — Hazard identification: lists GHS hazard categories and what health effects to expect
• Section 8 — Exposure controls / PPE: gives the Workplace Exposure Limit (WEL), recommended engineering controls, and the type of PPE specified by the manufacturer
• Section 13 — Disposal considerations: confirms how contaminated product and empty containers must be disposed of

Keep a copy of the current SDS for every hazardous substance used or stored on site. Outdated SDS documents are a common HSE finding during inspections — check that you are using the current version when formulations change.

Carrying Out a COSHH Risk Assessment

COSHH requires you to assess the risk from hazardous substances before work begins. The assessment does not need to be elaborate for routine tasks, but it must be systematic and recorded. Work through these steps:

• Identify the substances — list every product you will use and every substance the work itself will generate (dusts, fumes, vapours). Include items that are already on site and could be disturbed.
• Identify who could be harmed and how — consider the direct operative, nearby workers, apprentices, other trades on site, and any members of the public. Note the route of exposure (inhalation, skin contact, etc.).
• Evaluate the risk and existing precautions — compare likely exposure against the WEL where one exists. The HSE's COSHH Essentials online tool can help estimate exposure for common tasks without air monitoring. Consider how long and how often exposure occurs.
• Record your findings — write down the substances, the people at risk, the risk level, and the controls you are putting in place. For five or more employees, a written assessment is a legal requirement; for fewer, a written record is still strongly advisable.
• Review when circumstances change — a new substance on site, a new process, a change in workforce, or a health surveillance concern all trigger a review. Annual review is a sensible minimum for regularly performed tasks.

The HSE provides a free COSHH assessment template and an online COSHH Essentials tool (coshh-essentials.org.uk) that generates control guidance sheets for specific tasks. Reputable industry bodies including the FMB, NFRC, and ECA also publish trade-specific COSHH templates that are a practical starting point.

The Hierarchy of Control for COSHH

COSHH requires you to apply controls in a specific priority order. PPE is always last — not first.

• Elimination — can the task be redesigned so the hazardous substance is not used or generated at all? The best control is one that removes the hazard entirely.
• Substitution — replace the hazardous product with a less harmful alternative. Water-based paints instead of solvent-based; pre-wetted silica aggregate instead of dry bagging; chromate-free cement.
• Engineering controls — local exhaust ventilation (LEV), on-tool dust extraction connected to an H-class vacuum, water suppression during cutting, enclosed processes. These controls work regardless of worker behaviour and are therefore more reliable than administrative measures or PPE.
• Administrative controls — safe working procedures, job rotation to limit individual exposure duration, restricting access to hazardous areas, scheduling dusty work when fewer people are present, toolbox talks.
• PPE (last resort) — respirators, gloves, goggles, and protective clothing are used where residual risk remains after applying all higher-level controls. PPE protects only the wearer, depends entirely on correct use and fit, and fails if damaged or incorrectly worn.

In practice, most COSHH-compliant trade work uses a combination of substitution, engineering controls, and PPE together. The requirement is that you can demonstrate you have worked down the hierarchy — not that PPE is never used.

Respiratory Protective Equipment (RPE)

RPE is the most commonly required COSHH PPE in trade work, and also the most frequently misused. The key types are:

• Disposable FFP2 filtering facepiece — suitable for low-hazard nuisance dusts. Not adequate for silica dust, hardwood dust, or isocyanates.
• Disposable FFP3 filtering facepiece — the minimum standard for respirable crystalline silica (RCS) and hardwood dust. Single-use; must be discarded when contaminated or at the end of each shift. Must be face-fit tested.
• Half-face respirator with P3 filter — reusable; provides better protection factor than an FFP3 disposable for extended or high-concentration dust work. Filters must be changed on the manufacturer's recommended schedule — typically when breathing resistance increases or at a set interval.
• Full-face mask — required for spray painting, particularly when applying isocyanate-containing two-pack coatings. Provides eye and facial protection in addition to respiratory protection.
• Powered air-purifying respirator (PAPR) — a battery-powered hood or helmet that draws air through a HEPA filter. Does not require face-fit testing and is useful where tight-fitting RPE cannot be adequately sealed (beards, facial scarring, high workrate).

Face fit testing is a legal requirement for all tight-fitting RPE. A qualitative fit test (using a bitter or sweet aerosol challenge) or a quantitative fit test (measuring actual leakage with a particle counter) must be carried out for each individual worker with each model of mask they use. A mask that fits one person may not fit another. Fit testing must be repeated if the worker's face shape changes materially — significant weight change, dental surgery, or facial injury.

Silica Dust: The Major Occupational Hazard in Construction

Respirable crystalline silica (RCS) is the most serious occupational lung hazard in UK construction. Cutting, breaking, drilling, or grinding concrete, masonry, blocks, tiles, paving, and natural stone releases fine silica particles small enough to penetrate deep into the lungs. Repeated exposure causes silicosis — progressive, irreversible scarring of lung tissue — and significantly increases the risk of lung cancer. There is no cure for silicosis; the only option is prevention.

The Workplace Exposure Limit for RCS is 0.1 mg/m³ as an 8-hour time-weighted average (TWA). Uncontrolled dry cutting operations routinely generate silica concentrations 10 to 100 times this limit. You cannot see or smell silica at hazardous concentrations.

Required controls when working with silica-containing materials:

• Water suppression (wet cutting) — water applied continuously at the blade during cutting reduces airborne dust by over 90% when done correctly. Not suitable for all tasks or all tools.
• On-tool extraction — an H-class (HEPA-filtered) vacuum connected directly to the angle grinder, disc cutter, or block splitter captures dust at the point of generation. This is mandatory when dry cutting cannot be replaced by wet methods.
• FFP3 or P3 respirator as minimum RPE — a standard paper dust mask (FFP1 or FFP2) gives no meaningful protection against RCS. FFP3 is the minimum acceptable standard.

Silicosis diagnosed as a work-related disease must be reported to the HSE under RIDDOR 2013 (Reporting of Injuries, Diseases and Dangerous Occurrences Regulations). Because the disease typically develops 10 to 30 years after exposure, it is common for workers to be unaware of the damage being done in real time — which makes engineering controls, not just RPE, essential.

Wood Dust: Hardwood, Softwood, and MDF

Wood dust is a regulated hazardous substance. Hardwood dust is classified by the International Agency for Research on Cancer (IARC) as a Group 1 carcinogen — there is sufficient evidence it causes cancer in humans, specifically adenocarcinoma of the nasal cavity and paranasal sinuses. Softwood dust causes asthma and rhinitis with regular exposure.

The WELs for wood dust are:

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

MDF presents a compounded risk. In addition to wood dust, MDF contains urea-formaldehyde resin. Cutting or routing MDF releases both fine wood dust and formaldehyde vapour — formaldehyde is a known human carcinogen. Cutting MDF in a confined space without local exhaust ventilation can produce dust and formaldehyde concentrations far above WELs within minutes.

Required controls for wood dust work include:

• A Class M vacuum (for softwood) or Class H vacuum (for hardwood and MDF) connected directly to the saw, router, or sander — Class M captures at least 99% of dust particles, Class H at least 99.995%
• RPE at a minimum of FFP3 for hardwood and MDF work; FFP2 may be adequate for low-intensity softwood tasks but FFP3 is preferable
• General ventilation (open windows and doors) as a supplement to on-tool extraction — never as a replacement

Lead Paint in Older Properties

Properties built before approximately 1980 may have lead-based paint on walls, woodwork, or metalwork. Lead paint that is in good condition and undisturbed presents minimal risk. However, sanding, grinding, stripping, or burning off lead paint generates lead dust and fumes that are readily inhaled or ingested. Lead is a cumulative toxin affecting the nervous system, kidneys, and reproductive system. Children are especially vulnerable.

Lead at work is governed by the Control of Lead at Work Regulations 2002 (CLAW). Before disturbing paint in any pre-1980 property, you should:

• Test for lead — a handheld XRF analyser or a laboratory paint chip analysis confirms presence. Plumbsafe lead-testing swabs provide a quick on-site indication but are less reliable than XRF or lab analysis.
• Follow CLAW procedures if lead is confirmed — this includes a written CLAW risk assessment, provision of appropriate RPE (minimum P3 respirator) and disposable overalls, washing facilities with hot water, prohibition on eating, drinking, or smoking in the work area, and blood-lead monitoring if significant exposure is foreseeable.
• Notify the principal contractor if you are working as a subcontractor — the discovery of lead paint affects all trades working in the affected areas and must be communicated before work continues.

Lead paint waste (stripped material, used abrasives, contaminated PPE) is classified as hazardous waste and must be disposed of through a licensed hazardous waste contractor.

Record Keeping and Health Surveillance

COSHH imposes specific record-keeping requirements that go beyond the assessment itself:

• COSHH assessment records — must be retained for as long as the assessment remains relevant and for at least five years after it is superseded. For employers with five or more employees, a written assessment is a legal requirement.
• Health surveillance records — health surveillance is required where workers are regularly exposed to substances with a known link to specific diseases. For trade businesses, the key triggers are: silica dust (annual lung function tests and respiratory questionnaire), hardwood and MDF dust (respiratory and nasal health checks), and isocyanates (pre-employment and ongoing respiratory surveillance by an occupational health professional — workers who become sensitised must be permanently removed from isocyanate exposure). Health surveillance records must be kept for 40 years for substances causing long-latency diseases such as silicosis and nasal cancer.
• RIDDOR reports — any work-related disease including occupational asthma, silicosis, chrome ulcers, and occupational dermatitis diagnosed by a doctor must be reported to the HSE under RIDDOR 2013 within 21 days of the diagnosis being made.
• LEV examination records — local exhaust ventilation systems must be thoroughly examined and tested at intervals not exceeding 14 months. The examination must be carried out by a competent person and the record kept for at least five years.
• Training records — documented evidence that workers have received COSHH information and instruction. A toolbox talk record covering the specific substances in use on your jobs, their hazards, and the controls in place is sufficient for most trade operations.

HSE inspection focus areas for trades typically include: evidence that a COSHH assessment exists and is task-specific (not a generic template), whether engineering controls are in use before PPE, whether RPE has been face-fit tested, and whether workers can explain why the controls matter. Enforcement options include improvement notices requiring remedial action within a set timeframe, prohibition notices stopping work immediately, and prosecution under the Health and Safety at Work Act which carries unlimited fines and — for cases involving gross negligence — the possibility of imprisonment.