How do you do a COSHH assessment for cement and mortar?

Last checked 01-11-2026. A plain guide, not legal advice: check the official guidance below for your job.

Wet cement is strongly alkaline. It can burn skin, cause irritant and allergic dermatitis and damage eyes, and the powder irritates the nose and throat. Your COSHH assessment should cover who mixes and handles it, how you cut skin contact, washing, gloves and eye protection, skin checks and first aid. This guide covers Great Britain; Northern Ireland has its own COSHH Regulations (2003).

What the law asks for

HSE says the Control of Substances Hazardous to Health Regulations 2002 (COSHH) require you to protect people against the risks from cement-based products, following an assess, control and review approach. In the regulations themselves:

Assess first (regulation 6). You must not start work that could expose your employees to a hazardous substance until you have made a suitable and sufficient assessment of the risk and put the steps it identifies in place. It must consider the hazards of the product, the supplier's information including the safety data sheet, the level, type and how long people are exposed, and the circumstances of the work.
Write it down if you employ 5 or more people (regulation 6(4)): the significant findings and the steps you have taken. HSE says that even with fewer than 5 it makes sense to write down what you did.
Review it regularly, and straight away if there is reason to think it is no longer valid or the work has changed significantly (regulation 6(3)).
Others on site count too. So far as is reasonably practicable, your duties extend to other people affected by your work, such as other trades and the householder (regulation 3(1)).
Self-employed. COSHH applies to a self-employed person working on a construction site as if they were both employer and employee, except for the rules on exposure monitoring and health surveillance (regulation 3(2), with the 2015 regulations that list work on a construction site as a prescribed activity).

The hazards, and who is at risk

The safety data sheet for a common UK bagged cement classifies it with the signal word Danger and three hazard statements: H318 Causes serious eye damage, H315 Causes skin irritation and H335 May cause respiratory irritation. The same sheet gives the pH of cement in water as 11 to 13.5. What that means on site:

Cement burns. HSE says wet cement is highly alkaline, and a serious burn or ulcer can develop quickly if it is trapped against the skin, for example inside a glove or boot. In extreme cases these burns may need a skin graft or lead to amputation. The data sheet adds that the burns can develop without pain being felt, for example when kneeling in wet concrete even in trousers.
Irritant contact dermatitis. HSE says cement can abrade the skin and cause irritant contact dermatitis.
Allergic contact dermatitis. Cement contains hexavalent chromium (chromium VI), which can sensitise the skin. HSE says that once someone is sensitised, any future exposure may trigger dermatitis, and some skilled tradesmen have had to change trade because of it.
Eye damage. HSE says cement can cause chemical burns to the eyes. The data sheet says dry or wet cement in the eye may cause serious and possibly irreversible injury.
Dust. HSE says cement powder irritates the airways. The workplace exposure limits for Portland cement in HSE's EH40 are 10 mg/m3 (inhalable dust) and 4 mg/m3 (respirable dust), averaged over 8 hours. Cutting, drilling or raking out dried concrete and mortar is a different hazard: HSE says that dust can cause more serious lung disease. HSE's construction dust sheet CIS36 names concrete and mortar as materials that give off silica dust, which needs its own assessment.

Who to think about. HSE says workers handling or mixing cement powder, or using wet mortar and cement, are particularly at risk. On a small job that usually means bricklayers, the labourer on the mixer, groundworkers placing concrete, screeders, plasterers and tilers. HSE also says to check for existing skin or allergy problems, because this work could make them worse. Include anyone nearby when bags are emptied, and keep the householder and children away from mixing areas.

Chromium VI and the shelf-life rule

Cement makers add a reducing agent to keep the chromium VI low. The legal limit is in REACH Annex XVII, entry 47: cement and mixtures containing cement must not be sold or used if, once mixed with water, they contain more than 2 mg/kg (0.0002 percent) of soluble chromium VI of the total dry weight of the cement. Where a reducing agent is used, the bag must be marked with the packing date, the storage conditions and the storage period during which the reducing agent keeps working.

HSE says the reducing agent only works for a limited time, shown by the shelf date, and after that the chromium VI level may rise again. The data sheet we checked says the same: store it wrongly or keep it too long and the cement can become skin sensitising.

Check the packing date and storage period on every delivery.
Store bags unopened, off the ground and in cool, dry conditions, as the data sheet says.
Use the oldest bags first. HSE advises rotating stock so bags are used before the shelf date.
Do not use out-of-date bags. The data sheet says cement past its shelf life should not be used, other than in closed automated processes, and should be disposed of or treated again with a reducing agent. Ask your supplier what to do with it.
The rule covers cement-containing mixtures too, so check the dates on bagged mortar, post mix and similar products.

Controls, in the order the law sets

COSHH regulation 7 says exposure must be prevented or, where that is not reasonably practicable, adequately controlled. Substitution comes first. After that the order is: suitable work methods, equipment and materials; control at source; and personal protective equipment last, on top of the other measures, where they cannot give adequate control on their own. The controls must include suitable hygiene measures, including adequate washing facilities.

Cut the powder. HSE suggests using pre-mixed concrete or mortar so nobody handles cement powder.
Keep your distance. HSE suggests methods that keep the worker further from the material, such as longer-handled tools.
Keep it off the skin. HSE says to keep kneeling time to a minimum. Plan the job so people are not working in wet mixes.
Clean up dry spills with a vacuum, not a brush. The data sheet says do not sweep.
No eating, drinking or smoking while working with cement, as the data sheet advises, and wash before breaks.
Bags are heavy. Cover lifting and carrying in your manual handling assessment.

Washing facilities matter more for cement than for most products. HSE says to wash cement off the skin as soon as possible and to wash exposed skin at breaks and after work. Provide hot and cold or warm running water, soap and towels, with basins big enough to wash the forearms. Showers may be needed where people could get heavily covered, and you need emergency eyewash. HSE warns that some portable toilets only have hand sanitiser and a small sink, which is not enough unless proper washing facilities are nearby, and that washing should be kept apart from eating and rest areas where people work with cement. See welfare facilities for the full list.

PPE: gloves, eyes, sleeves and knees

Gloves. HSE says gloves should be waterproof and suitable for high pH (alkaline) substances, giving the example of gloves marked EN 374 and tested against alkalis and bases (class K). Some nitrile or PVC gloves may be suitable. The breakthrough time must suit the length of the job, and the cuff should be long or tight so cement cannot get trapped inside. The data sheet suggests nitrile-impregnated cotton gloves, and says to change damaged or soaked gloves at once and keep spares to hand. HSE also says comfortable gloves are more likely to be worn, so involve the people who will wear them in choosing.
Eye protection. The data sheet says to wear safety glasses or goggles to EN 166 when handling dry or wet cement.
Long sleeves and boots. The data sheet calls for closed, long-sleeved protective clothing and boots, and care that wet cement does not get into the boots. HSE says to wear wellington boots for large pours, high enough to keep cement out, with trousers worn over the top of the boots.
Knees. HSE says to wear waterproof trousers when kneeling on wet cement products, and waterproof knee pads or knee boards when screeding.
Skin care. HSE says skin care products can help protect the skin by replacing its natural oils. The data sheet advises barrier cream before work and moisturiser after.
Contaminated clothing. The data sheet says to take off clothing, footwear and watches with cement on them and clean them before they are worn again.

Skin checks and health surveillance

COSHH regulation 11 requires suitable health surveillance for employees where it is appropriate: where an identifiable disease may be linked to the exposure, it is reasonably likely to happen in the conditions of the work, and there are valid ways of detecting it. For cement, HSE says appropriate health surveillance is needed to check that your controls are preventing dermatitis. HSE guidance sheet G403 also says to consider it where workers rely on PPE to protect them from a substance that can cause dermatitis.

Get a baseline. HSE says to check a new worker's skin before they start, or as soon as possible after. G403 gives within six weeks as an example.
Check regularly. G403 gives annually as an example frequency, using a questionnaire and a skin inspection of the hands, forearms and face, and the lower legs if they can get contaminated. With only occasional exposure, or good control and no problems over a representative period, it says an annual questionnaire and a health record may be enough.
Use a responsible person. HSE says the checks can be done by an employee trained for it, supported by an occupational health professional.
Know the signs. G403 lists itching, scaling or flaking, dry or cracking skin, colour changes, blistering, weeping and soreness. Tell workers who to report symptoms to between checks.
Keep the records. Regulation 11 requires a health record for each employee under surveillance, kept for at least 40 years from the last entry. G403 says it should include name and address, National Insurance number, the products or processes, when exposure started and how often and how long, the PPE used, and the results.
If a doctor or occupational health professional links a worker's dermatitis to the work, regulation 11(9) says you must make sure the worker is told and advised, review the risk assessment and the controls, consider moving them to work without exposure, and review the health of others exposed in the same way.

The health surveillance duty does not apply to the self-employed, but checking your own skin against the same list costs nothing.

First aid

The first aid steps below are from the safety data sheet we checked. Use the data sheet for the product you are actually using, and keep eyewash where cement is mixed and used.

Eyes: do not rub. Remove contact lenses, hold the eyelids open and rinse straight away with plenty of clean water for at least 20 minutes. Then get the casualty seen by an eye specialist or an occupational doctor.
Skin: for dry cement, remove it and rinse with plenty of water. For wet cement, wash with plenty of water. Take off contaminated clothing, footwear and watches. The data sheet says to get medical treatment in all cases of irritation or burns. Do not wait for pain, because cement burns can develop without it.
Breathed in: move to fresh air. See a doctor if irritation or coughing carries on.
Swallowed: do not make the person sick. If they are conscious, rinse the mouth and give plenty of water, and get medical help straight away.
Take the safety data sheet with you to the doctor or hospital.

What to write down: an example

A COSHH assessment for cement does not need to be long. For brickwork on a single-storey extension at Telford Row, with two bricklayers and a labourer mixing mortar from bagged cement and sand for about four weeks, the record might read:

Products: bagged general purpose cement (data sheet on file), building sand. Ready-mixed concrete for the slab, delivered by truck.
Hazards: H318, H315, H335. Wet mix can burn skin and eyes. Chromium VI can cause allergic dermatitis once the reducing agent expires.
Who: the labourer mixing (powder and wet mortar, most of each day), the bricklayers (wet mortar on hands and forearms), the householder (kept out of the mixing area).
Controls: ready-mix for the slab, so no site mixing of concrete. Mixer set up downwind of the work area and away from the house door. Bags opened low down and emptied gently. Delivery dates checked on arrival, bags stored on a pallet under cover, oldest used first, out-of-date bags returned. Dry spills vacuumed.
Welfare: unit with hot and cold water, soap, towels and a basin big enough for forearms. Eyewash bottle at the mixer. Washing at every break.
PPE: nitrile-coated gloves marked EN 374 for alkalis, with spares. Safety glasses to EN 166 for mixing and pointing. Long sleeves. Knee pads for any kneeling work.
Health surveillance: skin checks at start and then as advised by our occupational health provider, done by the trained supervisor, records kept for 40 years.
First aid: as on the data sheet. First-aid kit and eyewash in the welfare unit.
Cutting and raking out: separate silica assessment.
Briefing: at induction and a toolbox talk on cement skin care in week one. Review: if the method, the product or the team changes, or if anyone reports skin problems.

COSHH regulation 12 requires employees to be given suitable information, instruction and training, including the names of the substances, the risks, access to the safety data sheet, the significant findings of the assessment and the precautions to take. HSE adds that workers need to know the signs and symptoms of dermatitis, because finding skin problems early can stop them getting worse.

How do you do a COSHH assessment for cement and mortar?

What the law asks for

The hazards, and who is at risk

Chromium VI and the shelf-life rule

Controls, in the order the law sets

PPE: gloves, eyes, sleeves and knees

Skin checks and health surveillance

First aid

What to write down: an example

Sources

Tools that help

More guides

The construction manager’s toolbox.