Commercial cleaning is the sector that generates the most under-reported COSHH incidents in the UK — chemical mixing in mop buckets, decanting from drums into unlabelled trigger-sprays, chlorine gas release from acid-and-bleach combinations in washrooms. A cleaning COSHH assessment under the Control of Substances Hazardous to Health Regulations 2002 has to cover every chemical the operative will touch, but more importantly it has to address the three operational realities that drive most incidents: dilution and decanting, the COSHH chain when the cleaner is sub-contracted, and the consumer-grade products that staff bring from home and use on site.
COSHH 2002 reg 6 requires an assessment of the risk from any substance hazardous to health. For commercial cleaning the substances are: chlorine-based disinfectants (sodium hypochlorite, dichloroisocyanurate / NaDCC tablets), quaternary ammonium disinfectants, washroom limescale removers (typically phosphoric, sulphamic or hydrochloric acid), kitchen degreasers and oven cleaners (sodium hydroxide / potassium hydroxide), floor strippers (typically ammonia or solvent-based), and increasingly hydrogen peroxide / peracetic acid for healthcare cleaning.
The assessment names each product by trade name, the supplier, the active hazardous ingredient and concentration, the CLP hazard class and pictograms from the safety data sheet (SDS), the workplace exposure limit (WEL) where set, and the route of harm (skin / eye / inhalation / ingestion). Generic 'cleaning chemical' lines fail COSHH 2002 reg 6 on their face.
Most cleaning products are supplied as concentrates that the operative dilutes on site. The two failure modes are: wrong dilution (under-dilution causes skin / eye / inhalation harm; over-dilution causes inefficacy and a false sense of disinfection), and decanting into an unlabelled trigger spray or mop bucket that another operative then mistakes for a different product. The COSHH assessment must name the dilution control measure — typically a dosing system (Brightwell / SEKO / equivalent) that delivers the manufacturer's dilution ratio automatically, or a labelled measuring jug with a written procedure.
Decanting into trigger sprays is permitted only where the spray is labelled with the product name, the active ingredient, the dilution ratio and the date. This is required under GB CLP — even decanted-on-site containers need a workplace label.
The most common acute incident in commercial cleaning is the release of chlorine gas when sodium hypochlorite (bleach) is mixed with an acid (typically a washroom limescale remover). The release can be enough to cause acute pulmonary oedema and is regularly RIDDOR-reported in hospitality and care home settings. The COSHH assessment must explicitly: prohibit the mixing of any chlorine-based product with any acidic product; name the colour-coding system that segregates washroom products from kitchen / general products (typically red = washroom, blue = general low-risk, green = food / kitchen, yellow = clinical); and name the operative training that covers incompatible mixtures.
For healthcare cleaning the assessment also covers the use of chlorine releasing agents at elevated concentration for C. diff / norovirus outbreak cleaning and the increased respiratory and skin exposure that requires specific PPE (nitrile gloves, surgical mask, eye protection).
Contract managers, facilities clients (especially in healthcare, education and food premises) and CHAS / SMAS / SafeContractor assessors read the document in this order: the inventory of products with SDS reference dates; the dilution and decanting procedure; the incompatible-mixture prohibition; the colour-coding system; the PPE matrix by product; spill response with the named spill kit on site; and the health surveillance arrangement (skin checks for staff using chlorine releasing agents or nitrile-glove rotation for staff with confirmed latex / glove sensitisation).
SDSs older than 12 months are a routine adverse finding because product formulations and CLP classifications change. The assessment review cycle should mirror the SDS review cycle plus a standing trigger for any new product introduced to site.
The numbered sections a reviewer expects to see, in order.
Premises type, areas cleaned (washrooms, kitchens, clinical, general), contract manager and on-site supervisor.
Each product by trade name, supplier, SDS reference date, active hazardous ingredient and concentration, CLP class, WEL where set.
Dosing system or labelled measuring jug; trigger-spray labelling requirements; named-operative responsibility for decants.
Explicit prohibition of bleach + acid; colour-coded equipment and store segregation; training reference.
Gloves (material and length), eye protection, apron, RPE where required — selected by product and task, with replacement frequency.
Spill kit location and contents, neutralisation procedure for acids and alkalis, evacuation threshold and ventilation route.
Locked chemical store, segregation of acids from chlorine-based products, ventilation, secondary containment for drums.
Manufacturer training where required (e.g. dosing system, oven cleaner), BICSc / CGCS competence, induction and refresher cycle.
Skin checks for chlorine releasing agent users, glove rotation for sensitisation, asthma surveillance where required.
Route to RIDDOR for any over-7-day injury, occupational asthma, chemical burns; internal incident-log review.
Why a coshh assessment gets sent back — these are the patterns we see most often.
The legal framework this coshh assessment operates inside. Links go to the official source.
SI 2002/2677
The statutory framework — assessment, prevention or control, exposure monitoring and health surveillance.
HSE L5
The principal guidance on the COSHH duties and the recognised compliance framework.
GB CLP
Workplace labelling requirements — applies to decanted-on-site containers.
HSE EH40
The published WELs that the COSHH assessment must check against for any inhalation-route exposure.
HSE INDG136
Plain-English summary — the standard reference for operative training content.
SI 2013/1471
Notification regime for over-7-day injuries, occupational asthma and dangerous occurrences.
Whenever a new product is introduced, when an SDS is reissued by the manufacturer, after any incident, and as a minimum annually. Most contract clients (healthcare, education, food premises) also require a contract-start review and an annual re-issue regardless of mid-contract changes.
Yes, provided the spray is labelled in workplace format under GB CLP — product name, active ingredient, dilution ratio and date — and the dilution follows the manufacturer's SDS. Unlabelled decants are a common adverse finding and are the leading cause of accidental mixing incidents.
It releases chlorine gas, which at low concentrations causes eye and respiratory irritation and at higher concentrations causes pulmonary oedema. The most common cause of acute hospital admissions from cleaning work in the UK. The assessment must explicitly prohibit the combination and the operative training must cover it.
Yes. The choice of glove material is product-specific — nitrile is the general-purpose choice for cleaning chemicals; latex is to be avoided where any chance of sensitisation exists; PVC is appropriate for some specific chemicals. The assessment names the glove material per product, not just 'gloves'.
It should explicitly prohibit them. Consumer-grade products do not come with workplace SDS, are not in the assessment, and are not covered by the dilution / PPE / incompatibility procedures. Most adverse incidents the HSE investigates in the sector involve a domestic product brought from home.
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Final RAMS must be reviewed and approved by a competent person before use.