COSHH Assessment for Cleaning Chemicals: A Practical Guide for UK Tradespeople

Cleaning chemicals are among the most routinely mishandled substances on UK construction and maintenance sites. Degreasers, descalers, bleach-based products and solvent cleaners can cause serious skin, eye and respiratory harm — yet they often get used without a second thought. Under the Control of Substances Hazardous to Health Regulations 2002 (COSHH), employers and self-employed workers have a legal duty to assess and control the risks before work begins.

This guide explains how to carry out a COSHH assessment for cleaning chemicals in a way that actually holds up on site.

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What COSHH Requires

COSHH Regulation 6 requires a "suitable and sufficient" assessment of the risks created by hazardous substances — and cleaning products clearly fall within scope. The assessment must consider:

• The hazardous properties of each substance
• Who might be exposed and how (inhalation, skin contact, ingestion, injection)
• The likelihood and degree of exposure
• What controls are necessary to prevent or adequately control that exposure

The assessment is not a one-off form-filling exercise. It must be reviewed if conditions change — for example, if you switch products, move to a confined space, or a worker reports symptoms.

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Step 1: Identify the Substances in Use

List every cleaning chemical used on the job. This includes products that seem mild, such as multi-surface sprays or bathroom cleaners. Check the product label and obtain the Safety Data Sheet (SDS) from the supplier or manufacturer — this is your primary source of hazard information. SDSs follow a standard 16-section format under UK REACH and must be provided free of charge.

Pay particular attention to:

• Section 2 – Hazards identification (GHS/CLP hazard statements)
• Section 8 – Exposure controls and PPE
• Section 11 – Toxicological information

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Step 2: Identify Who Could Be Harmed and How

Consider everyone who may come into contact with the substance — not just the person applying it. On a busy site this can include other trades working nearby, building occupants, or members of the public passing through.

Common exposure routes for cleaning chemicals:

Confined spaces dramatically increase inhalation risk — what is tolerable in a ventilated room may exceed Workplace Exposure Limits (WELs) within minutes in a poorly ventilated tank or duct.

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Step 3: Evaluate the Risk and Apply the Correct Controls

COSHH requires you to prevent exposure where reasonably practicable, and where prevention is not possible, to adequately control it. Apply controls in the correct hierarchy — do not jump straight to PPE.

Eliminate — Can the task be done without a chemical? Sometimes a mechanical method (scrubbing, steam cleaning) removes the need for a hazardous product entirely.

Substitute — Can a less hazardous product achieve the same result? A pH-neutral cleaner instead of a concentrated acid descaler, for example. Check the SDS of the alternative before assuming it is safer.

Engineering controls — Ensure adequate ventilation. In enclosed areas, use local exhaust ventilation (LEV) or forced-air ventilation before relying on PPE. Dilution ventilation alone is rarely sufficient for highly volatile solvents.

Administrative controls — Restrict access to areas being cleaned; schedule cleaning outside normal working hours to reduce bystander exposure; limit the quantities brought onto site; train workers on safe handling and correct dilution rates. Concentrated products used neat are a common and avoidable cause of burns.

PPE (last resort) — Select PPE based on the SDS and the specific task. Nitrile gloves provide better chemical resistance than latex for most cleaning chemicals, but check the manufacturer's breakthrough time data. Eye protection (chemical splash goggles, not just safety glasses) is needed wherever splashing is possible. Respiratory protective equipment (RPE) must be the correct type — a dust mask (FFP3) offers no protection against solvent vapour; you may need a half-mask with the appropriate filter cartridge.

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Step 4: Record the Assessment

If you employ five or more people you must record your COSHH assessment in writing under COSHH Regulation 6(4). In practice, even sole traders and small contractors should keep a written record — it demonstrates due diligence and helps with RAMS documentation.

A COSHH assessment record for cleaning chemicals should cover:

• Product name and SDS reference date
• Hazardous ingredients and their WELs (where HSE has set one)
• Who is exposed and how
• Controls in place (matched to the hierarchy above)
• PPE specified, including grade and standard
• Health surveillance requirements (relevant if there is significant skin or respiratory exposure)
• Review date

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Step 5: Communicate and Review

The assessment is only useful if workers actually see it. Brief your team before the task, not after something goes wrong. Under COSHH Regulation 12, employers must provide employees with suitable and sufficient information, instruction and training on the substances they work with.

Review the assessment whenever:

• A product is changed or a new one introduced
• Working conditions change (confined space, different season, different PPE stock)
• A worker reports skin irritation, headaches or breathing difficulties
• An incident or near-miss occurs

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A Common Mistake to Avoid

Many contractors copy a generic COSHH assessment from the internet and attach it to a RAMS without checking whether it matches the actual products on site. HSE inspectors and principal contractors do check product names against SDS references. An assessment that refers to "general degreaser" when you are actually using a specific chlorinated solvent is not suitable and sufficient — and will not protect your workers or your business.

Take the time to base each assessment on the real SDS for the exact product you are using. That is what the law requires, and it is what keeps people safe.