COSHH assessments for cleaning businesses: what you're legally required to do — and how to do it

Most cleaning business owners know vaguely that COSHH exists. Far fewer have actually completed a COSHH assessment — and many assume it only applies once they have employees or take on industrial work. That assumption is wrong, and it's one that can cost you a commercial contract or a HSE improvement notice.

COSHH — the Control of Substances Hazardous to Health Regulations 2002 — applies the moment you pick up a hazardous substance in the course of your work. That includes bleach in a domestic bathroom, acidic descaler in a commercial kitchen, and oven cleaner on a rental property end-of-tenancy clean. This guide explains what a COSHH assessment actually involves, walks through a complete worked example, and tells you exactly what records you need to keep.

What is COSHH?

COSHH stands for the Control of Substances Hazardous to Health Regulations 2002, a statutory instrument made under the Health and Safety at Work etc. Act 1974. The regulations require employers — and self-employed people — to control substances that are hazardous to health. The Health and Safety Executive (HSE) is the enforcing body in Great Britain.

The regulations apply to any substance that can cause harm when inhaled, ingested, absorbed through the skin, or when it comes into contact with the eyes. In the context of cleaning, that covers virtually everything in your kit bag beyond water. The law defines "hazardous" broadly, using the hazard classifications under the Classification, Labelling and Packaging (CLP) Regulation. In practical terms, you're looking at:

• Irritants: substances that cause inflammation on contact — most household bleaches, some disinfectants, many degreasers
• Corrosives: substances that destroy living tissue on contact — acid descalers, caustic oven cleaners, drain unblockers
• Sensitisers: substances that can trigger allergic reactions over repeated exposure — certain biocidal disinfectants, fragranced products
• Toxic substances: substances that can cause serious harm in small doses — rarely encountered in domestic cleaning, more common in industrial settings
• Harmful substances: substances with lower toxic potential but still requiring controls — most cleaning products fall somewhere in this category

COSHH does not apply to substances covered by their own specific legislation (radioactive materials, asbestos, lead) — those have separate regulations. Everything else in your cleaning supplies is fair game.

Who needs a COSHH assessment?

Any person who uses hazardous substances in the course of their work must carry out a COSHH assessment. This includes:

• Sole traders who clean domestic properties
• Sole traders who clean commercial premises
• Limited companies employing cleaning operatives
• Self-employed contractors working within a larger operation
• Cleaning businesses that supply staff to client sites

The size of your business is irrelevant. A one-person domestic cleaning round carrying bleach and multi-surface spray is legally required to have COSHH assessments in the same way as a contract cleaning company with 200 staff. The assessment for the sole trader will obviously be shorter and simpler — but it must exist.

There is a common misconception that COSHH only matters for commercial or industrial cleaning — the kind involving industrial solvents, specialist chemicals, or confined-space work. In reality, sodium hypochlorite (bleach) is classified as an irritant and corrosive in concentrated form, and it appears in the product under almost every sink in the country. If you're using it professionally, you need an assessment for it.

How to carry out a COSHH assessment: 6 steps

The HSE's approach to COSHH assessment follows a straightforward six-step process. There is no prescribed format — the law requires that you assess and control risks, not that you use a particular template. However, your assessment must be written down if you have five or more employees; and even below that threshold, a written record is strongly advisable because commercial clients almost always ask to see it.

1. 1
   Identify which substances you use. List every product by its trade name and, where possible, its active ingredient. Don't overlook anything: floor stripper, toilet cleaner, descaler, glass cleaner, disinfectant, air freshener, carpet shampoo. If it has a warning symbol on the label, it belongs on your list. If you're unsure whether something is hazardous, it's safer to include it and assess it at low risk than to omit it.
2. 2
   Find the Safety Data Sheet (SDS) for each product. A Safety Data Sheet is a standardised document — 16 sections — that describes a substance's hazards, safe handling requirements, first-aid measures, PPE requirements, and disposal guidance. Suppliers are legally required to provide SDS documents free of charge. Most are available on manufacturer websites. If a supplier won't provide one, consider switching supplier. The SDS is the primary source of information for your COSHH assessment — Section 2 (hazard identification), Section 8 (exposure controls and PPE), and Section 11 (toxicological information) are the most relevant.
3. 3
   Identify who is at risk and how they are exposed. For each substance, think through: who handles it directly (your operatives), who might be indirectly exposed (clients, members of the public, other workers on site), and how exposure occurs. The main routes of exposure in cleaning are: inhalation of vapour or aerosol, skin contact, and eye splash. Ingestion is a risk mainly in food-service settings where surfaces are cleaned and then used for food preparation.
4. 4
   Rate the risk using likelihood and severity. Multiply the likelihood of exposure (1–3) by the severity of harm if exposure occurs (1–3) to get a risk score of 1–9. The matrix below explains what each score means in practice. Be honest — don't downgrade risks because it makes the paperwork easier. A risk score is only useful if it reflects reality.
5. 5
   Decide on control measures. COSHH requires you to eliminate or reduce risks "so far as is reasonably practicable". The hierarchy of controls runs: eliminate the substance (stop using it), substitute it with a safer alternative, enclose the process, control exposure through engineering (ventilation), apply safe systems of work (training, procedures), and finally use PPE. PPE should be the last line of defence, not the first. If you can achieve adequate control by diluting a product correctly and ensuring ventilation, a full face shield is disproportionate.
6. 6
   Record, implement, and review. Write down your assessment — what the substance is, who's at risk, what the risk score is, and what controls are in place. Communicate it to anyone who uses the product. Set a review date (at minimum annually, and sooner if the product changes, your working methods change, or someone has an incident). A COSHH assessment that sits in a drawer unread does not constitute adequate control.

Understanding the risk rating matrix

The risk rating matrix used in COSHH assessments is the same one used across general health and safety risk assessment. You multiply two scores together:

• Likelihood (1–3): How probable is it that an operative or third party will actually be exposed to the substance? 1 = Rare (unlikely under normal working conditions), 2 = Possible (could reasonably occur in routine use), 3 = Likely (expected to occur regularly)
• Severity (1–3): How serious would the harm be if exposure did occur? 1 = Minor (superficial irritation, recovers quickly), 2 = Moderate (significant irritation, possible medical attention), 3 = Severe (serious injury, hospitalisation, long-term effects, death)

For the majority of cleaning chemicals used at the dilutions specified on labels, risk scores of 2–4 (Low to Medium) are typical. High scores (6–9) arise with undiluted concentrated products, chemicals used in confined unventilated spaces, or products with acute toxic classifications. Neat caustic soda (sodium hydroxide) used for drain clearing, for example, would typically score 6 or higher.

Common cleaning chemicals and their COSHH classification

The table below covers the chemicals found in most cleaning operatives' kits. Risk levels assume dilute, label-directed use by a trained operative with appropriate PPE. Using neat concentrated product, or using in confined unventilated spaces, will increase both likelihood and severity scores.

Worked example: COSHH assessment for bleach-based bathroom cleaner

Below is a completed COSHH assessment for one of the most common substances in domestic and commercial cleaning. This is the level of detail the HSE would expect to see, and the level that commercial clients typically require before awarding contracts.

What records do you need to keep?

The law requires written records of your COSHH assessments if you have five or more employees. Even if you're a sole trader below that threshold, the practical reality is that commercial clients — schools, councils, NHS trusts, managing agents, facilities management companies — almost always ask to see your COSHH assessments before work begins. Not having them in writing will cost you contracts.

Your written record must cover, for each substance:

• Substance name — trade name and active ingredient where known
• Hazard classification — irritant, corrosive, sensitiser, etc. (from the SDS)
• Who could be exposed — operatives, clients, members of the public
• How exposure could occur — inhalation, skin contact, ingestion, eye contact
• Risk rating — likelihood × severity
• Control measures in place — substitution, ventilation, PPE, training
• PPE required — specific items, not just "gloves"
• Review date

There is no legally mandated format. A Word document, an Excel spreadsheet, or a printed form all work. The format matters less than the content — if your assessment is thorough and accurate, a simple table is perfectly adequate.

Keep records for the duration of the substance's use in your business, plus at least five years. If someone suffers an injury related to a chemical, you will be asked to produce your assessment. If you can't, the assumption will be that you didn't have one.

PPE requirements and employer responsibilities

Personal Protective Equipment is governed by the Personal Protective Equipment at Work Regulations 1992 (amended 2022 to extend to workers as well as employees). If you have employees or workers, the key obligations are:

• PPE must be provided free of charge. You cannot require employees or workers to purchase their own PPE. This applies regardless of whether they work full-time, part-time, or on a casual basis. If your COSHH assessment identifies nitrile gloves as required, you must provide them.
• PPE must be suitable. It must be appropriate to the risk, fit the wearer (a one-size glove that's too large offers inadequate protection), and be maintained in good condition. Worn-out or holed gloves do not count as PPE provision.
• Training counts as part of PPE provision. You must show operatives the SDS for every chemical they use, explain what the hazards are, and demonstrate how to use PPE correctly. A box of gloves on a shelf that nobody knows how to put on correctly is not compliant.
• PPE is a last resort, not a first resort. The hierarchy of controls requires you to reduce risk through elimination, substitution, and engineering controls before reaching for PPE. If ventilation would reduce exposure to an acceptable level, you must ventilate — and then also provide gloves for incidental contact.

For self-employed sole traders with no employees, the personal protective equipment obligations are self-directed — but the HSE's guidance is clear that you should protect yourself to the same standard you would be required to provide for an employee doing the same work.

Free COSHH assessment template

The structure of a COSHH assessment is straightforward, but filling one in from scratch for every chemical you use is time-consuming. A good template pre-populates the hazard classifications and SDS references for the most common cleaning chemicals, leaving you to add your specific controls, PPE provision, and review dates.

A complete COSHH assessment template for cleaning businesses should include the following columns for each substance:

Having your COSHH assessments in order before you pitch for commercial work makes a genuine difference. Facilities managers and procurement teams at schools, councils, and property management companies often screen supplier documentation before a meeting is even offered. A clean, complete, dated COSHH assessment pack signals that you run a professional operation — and it removes a standard objection from the contract conversation entirely.