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Construction compliance guide

COSHH Assessment Example for Construction: Step-by-Step Guide

A complete worked example of a COSHH assessment for cement — the most common hazardous substance on UK building sites. Follow this template section by section to create your own.

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Nicola Dobbie·Founder, The Site Book

TL;DR

  • • Every hazardous substance on site needs a COSHH assessment — cement, silica dust, solvents, adhesives, and more.
  • • A good assessment covers eight sections: substance details, hazard classification, exposure routes, control measures, PPE, storage, spill procedures, and health surveillance.
  • • Start with the manufacturer’s safety data sheet (SDS) — it contains the information you need.
  • • The assessment must be specific to your site and your work, not a generic copy-paste.
  • • Review whenever substances, methods, or conditions change — and at least once a year.

Why use a worked example?

Most builders know they need COSHH assessments. The problem is not awareness — it is knowing what to actually write. The HSE’s COSHH guidance explains the legal requirements, but it does not hand you a finished document for the substances you use every day.

This guide walks through a complete COSHH assessment for Portland cement — one of the most common hazardous substances on UK construction sites. We have chosen cement because almost every builder works with it, the hazards are well documented, and the control measures are practical and achievable. By following this example, you will understand the structure and level of detail expected, and you can adapt it for any other substance on your site.

If you need a broader introduction to COSHH before diving into this example, read our COSHH for Builders guide first. This page assumes you understand the basics and want to see how a real assessment looks.

Section 1: Substance details

The first section of any COSHH assessment identifies the substance you are assessing. This information comes directly from the product label and the manufacturer’s safety data sheet (SDS). Every supplier is legally obliged to provide an SDS for hazardous products — ask your builders’ merchant or download it from the manufacturer’s website.

Product name

Portland cement (OPC) — CEM I 42.5N. Record the exact product name as it appears on the bag or container. If you use multiple brands, note each one or confirm they share the same hazard profile.

Manufacturer / supplier

Record the manufacturer name and your supplier. For example: Hanson Cement, supplied by Travis Perkins. This ensures traceability if you need to request updated safety data sheets.

CAS number

Portland cement: 65997-15-1. The CAS (Chemical Abstracts Service) number is a unique identifier for the substance. You will find it in Section 3 of the safety data sheet. It helps confirm you are assessing the correct substance.

Physical form and appearance

Fine grey powder. When mixed with water, it forms a wet paste or slurry. Both forms present different hazards — the powder generates airborne dust, while the wet form is highly alkaline and causes chemical burns on contact with skin.

Where and how it is used on this project

Mixing mortar for brickwork. Mixing concrete for foundations and pad footings. Pointing and rendering. Approximately 40 bags (25 kg each) will be used over four weeks. Mixed by hand and by electric mixer on site.

Being specific matters. Writing “cement” is not enough. The HSE wants to see that you have identified the actual product, obtained the safety data sheet, and understood how it will be used on your particular project.

Section 2: Hazard classification

This section records the formal hazard classification from the safety data sheet. Under the CLP Regulation (Classification, Labelling and Packaging), every hazardous substance is assigned hazard statements (H codes) and precautionary statements (P codes). For Portland cement, the key classifications are:

  • H315 — Causes skin irritation. Wet cement is strongly alkaline (pH 12-14) and causes chemical burns with prolonged contact.
  • H318 — Causes serious eye damage. Cement dust or splashes of wet cement in the eyes can cause permanent damage, including blindness.
  • H317 — May cause an allergic skin reaction. Hexavalent chromium (Cr VI) in cement can cause allergic contact dermatitis. UK and EU regulations limit Cr VI content, but sensitisation is still possible.
  • H335 — May cause respiratory irritation. Cement dust irritates the nose, throat, and lungs. Prolonged inhalation can cause chronic bronchitis.
  • Contains crystalline silica — respirable crystalline silica (RCS) is classified as a carcinogen. Long-term inhalation causes silicosis and is linked to lung cancer.

The workplace exposure limit (WEL) for Portland cement is 10 mg/m³ (inhalable dust) and 4 mg/m³ (respirable dust), as published in the HSE’s EH40 Workplace Exposure Limits document. For respirable crystalline silica, the WEL is 0.1 mg/m³. These limits are averaged over an 8-hour time-weighted average (TWA).

Section 3: Exposure routes and who is at risk

This section identifies how people could be exposed to the substance and who might be affected. For cement, there are three primary exposure routes:

Inhalation

Cement dust becomes airborne when bags are opened, poured, and mixed. Cutting, grinding, or chasing cured concrete and mortar also generates respirable dust containing crystalline silica. Dust can travel across the site, affecting workers who are not directly handling cement. Windy conditions significantly increase the risk.

Skin contact

Wet cement is the primary skin hazard. It is highly alkaline and causes chemical burns, often without the worker feeling pain immediately. Cement dermatitis — both irritant and allergic — is one of the most common occupational skin diseases in UK construction. Dry cement dust also irritates exposed skin, particularly in hot weather when workers are sweating.

Eye contact

Cement dust blown into the eyes or splashes of wet cement cause serious damage. The alkaline nature of cement means eye injuries can progress rapidly. Even a small splash that is not washed out immediately can cause permanent scarring of the cornea.

Who is at risk: bricklayers, labourers mixing mortar and concrete, groundworkers pouring foundations, anyone cutting or grinding cured concrete or blockwork, and bystanders working nearby. On a small domestic project, that might be just one or two people. On a larger site, the dust and wet cement exposure could affect everyone in the immediate area. Record the specific roles and tasks in your assessment.

Section 4: Control measures

Control measures must follow the hierarchy of controls set out in the COSHH Regulations 2002. You must consider elimination and substitution before relying on engineering controls, and engineering controls before PPE. Here is what this looks like for cement:

Elimination

Can you avoid using cement altogether? On some projects, pre-cast concrete elements, pre-mixed products, or alternative materials can eliminate on-site cement mixing. For most bricklaying and groundwork, elimination is not practical — but you should always consider it first.

Substitution

Can you use a less hazardous product? Low-chromate cement reduces the risk of allergic dermatitis. Pre-mixed mortar (silo or tub) reduces dust exposure during mixing because the cement is already combined with sand and water. Where practical, use ready-mix concrete rather than mixing on site.

Engineering controls

Use water suppression when cutting concrete or blockwork — a wet saw or wet-cutting disc reduces airborne silica dust by up to 90%. Position mixing areas downwind of other workers. Use enclosed or semi-enclosed mixing stations where feasible. On larger jobs, local exhaust ventilation (LEV) can capture dust at the source.

Administrative controls

Limit the time any individual spends mixing or working with wet cement. Rotate tasks where possible. Ensure all workers receive COSHH training covering the specific hazards of cement. Display safety data sheets and COSHH assessment summaries at the mixing station. Provide washing facilities with clean running water close to the work area.

Personal protective equipment (last resort)

PPE is the final layer of protection, not a substitute for the controls above. See the next section for specific PPE requirements. The key point is that PPE only works if it is the right type, fits properly, and is actually worn consistently.

Section 5: PPE requirements

For cement work, the following PPE should be specified in your COSHH assessment. Remember that PPE is the last line of defence — you must still implement the engineering and administrative controls above. For detailed guidance on construction PPE, see our PPE in construction guide.

  • Waterproof gloves — not standard rigger gloves. Use nitrile or PVC gloves rated for alkaline substances. Cement eats through fabric and leather gloves. Replace gloves immediately if they are torn or show signs of degradation.
  • Eye protection — safety goggles (not just glasses) when there is any risk of splashing wet cement or airborne dust. Goggles should seal around the eyes to prevent dust entry from the sides.
  • Respiratory protective equipment (RPE) — an FFP3 disposable mask as a minimum when mixing dry cement or cutting concrete. For prolonged or heavy dust exposure, a powered air-purifying respirator (PAPR) provides better protection and is more comfortable for extended use. All RPE must be face-fit tested.
  • Long sleeves, full-length trousers, and waterproof boots — no exposed skin when handling wet cement. Tuck trousers into boots to prevent wet cement running down into your footwear. If cement gets inside your boots, the confined contact causes severe burns.
  • Barrier cream — applied to exposed skin as an additional layer of protection, not a replacement for gloves. Apply before starting work and reapply after washing. Barrier cream helps when removing cement residue and protects skin that might be briefly exposed during glove changes.

Section 6: Storage and handling

Proper storage and handling prevent accidental exposure and keep the substance in good condition. For Portland cement on a construction site, your assessment should include these requirements:

  • Store cement bags in a dry, covered area — a lockable container, covered pallet, or weatherproof store. Damp cement hardens in the bag and becomes unusable, but more importantly, damaged bags release dust that workers inhale.
  • Stack bags no more than six high to prevent collapse. Use a pallet as a base to keep bags off the ground. Ensure the storage area is on firm, level ground.
  • Keep safety data sheets accessible near the storage area. Workers should be able to check the SDS without leaving the work zone.
  • Do not store cement near drains, watercourses, or food and drink areas. Cement is alkaline and harmful to aquatic life. Spills that reach watercourses can result in Environment Agency prosecution.
  • Use good manual handling practice when moving bags. A 25 kg bag of cement is heavy and awkward. Consider mechanical handling aids, particularly if workers are moving multiple bags. See our guide on manual handling for more detail.
  • Dispose of empty bags and cement waste in accordance with local authority requirements. Do not burn empty bags on site.

Section 7: Spill and emergency procedures

Your COSHH assessment must include emergency procedures for spills and accidental exposure. These should be practical, specific, and communicated to everyone on site.

Skin contact

Remove contaminated clothing immediately. Wash affected skin with clean water for at least 20 minutes. Do not use solvents or abrasive cleaners. If cement has been inside gloves or boots for any length of time, seek medical attention — chemical burns from cement often look minor initially but worsen over the following hours. Wet cement burns are a medical emergency.

Eye contact

Irrigate the eye immediately with clean water or sterile eyewash for at least 20 minutes. Hold the eyelids open during irrigation. Do not rub the eye. Seek immediate medical attention — cement in the eye is treated as a chemical burn and may require specialist ophthalmic treatment. Time is critical.

Inhalation

Move the person to fresh air immediately. If they are coughing or experiencing difficulty breathing, seek medical advice. If symptoms are severe or the person loses consciousness, call 999. Prolonged or heavy inhalation of cement dust can cause chemical irritation of the respiratory tract.

Dry cement spill

Avoid creating dust — do not sweep dry cement with a broom. Dampen the spill with water before cleaning up. Use a shovel to collect the material. If the spill is large or in an enclosed area, wear RPE during clean-up. Prevent cement from entering drains or watercourses.

Wet cement spill

Contain the spill with sand or earth barriers. Do not wash wet cement into drains — it is alkaline and harmful to aquatic life. Allow small spills to harden, then remove mechanically. For large spills, use a pump or vacuum tanker and contact the Environment Agency if there is any risk of contamination reaching a watercourse.

Ensure eyewash bottles or a clean water supply are available at the mixing station and within 30 seconds of any area where wet cement is being used. Check and replace eyewash bottles before their expiry date.

Section 8: Health surveillance

The COSHH Regulations require health surveillance where workers are regularly exposed to substances that can cause identifiable diseases or adverse health effects. For cement, this means:

  • Skin checks — regular visual inspections of hands, forearms, and any other exposed skin for signs of dermatitis (redness, cracking, itching, blistering). The HSE recommends using their MDHS 47 skin inspection checklist. A trained supervisor can carry out these checks — you do not necessarily need an occupational health nurse.
  • Frequency — baseline check before a worker starts cement-related tasks, then at regular intervals (typically every three to six months for regular cement workers). Increase frequency if problems are detected.
  • Respiratory surveillance — if workers are regularly exposed to cement dust and silica, consider lung function testing (spirometry) as part of a broader health surveillance programme. This is particularly important for workers who cut, grind, or chase concrete as part of their daily work.
  • Record keeping — maintain health surveillance records for at least 40 years. This is a legal requirement under COSHH. Records should include the worker’s name, date of surveillance, the outcome, and any referrals made.
  • Action on findings — if health surveillance identifies a problem, the worker must be referred to an occupational health professional. Review and improve your control measures. Consider whether other workers are also at risk.

Common mistakes to avoid

Having reviewed thousands of COSHH assessments, these are the errors that come up again and again on construction sites:

Copying a generic template without adapting it

Your COSHH assessment must be specific to your project, your substances, and your working conditions. A photocopied template with no site-specific details will not satisfy the HSE and, more importantly, will not protect your workers.

Listing PPE as the only control measure

PPE is the last resort in the hierarchy of controls, not the first. If your assessment jumps straight to "wear gloves and a mask" without considering elimination, substitution, or engineering controls, it does not comply with the regulations.

Forgetting about bystanders

Dust travels. Vapours spread. Your assessment must consider everyone who might be exposed, not just the person doing the task. The labourer working five metres downwind of the cement mixer is being exposed too.

Not recording the assessment

If you employ five or more people, you must record your COSHH assessments in writing. Even if you are a sole trader, written records demonstrate to clients, principal contractors, and the HSE that you have done the work.

Treating it as a one-off exercise

A COSHH assessment is a living document. It must be reviewed when conditions change, when new substances are introduced, or when there is reason to believe the controls are not working. Filing it away and never looking at it again defeats the purpose.

Linking your COSHH assessment to RAMS

Your COSHH assessment does not exist in isolation. It should feed directly into your Risk Assessments and Method Statements (RAMS). When you write a method statement for bricklaying, for example, the COSHH controls for cement should be embedded in the step-by-step procedure.

In practice, this means your method statement references the COSHH assessment and includes the control measures as part of the working procedure. For example: “Before mixing mortar, don waterproof gloves and FFP3 mask. Position mixer upwind of other workers. Use water suppression if cutting blocks.” The COSHH assessment provides the detailed justification; the method statement turns it into practical instructions.

If you are using The Site Book to create RAMS, COSHH considerations are included automatically. When you describe your project and mention cement work, the system identifies the substance hazards and builds the relevant controls into your method statement — saving you the time of cross-referencing manually.

Adapting this example for other substances

The eight-section structure above works for any hazardous substance you encounter on site. Here is how to approach the most common ones:

PVA adhesive

Generally lower hazard than cement, but still requires assessment. Key risks are eye irritation and mild skin irritation. Control measures focus on eye protection, basic gloves, and good ventilation. The SDS will confirm whether the specific product contains any sensitisers.

Silicone sealant

Acetoxy-cure silicones release acetic acid vapour (the vinegar smell). Key hazards are eye and respiratory irritation. Work in well-ventilated areas, avoid enclosed spaces, and provide eye protection. Some specialist silicones contain fungicides that require additional controls.

Solvent-based paints and varnishes

Higher risk due to volatile organic compound (VOC) vapours. Key hazards include dizziness, headaches, and long-term organ damage. Ventilation is critical — forced ventilation in enclosed spaces. Consider water-based alternatives (substitution). Specific RPE with organic vapour filters may be needed.

Dust from cutting and grinding

Silica dust from concrete, brick, block, and stone. Wood dust from timber cutting. Both are serious long-term health hazards. Water suppression and on-tool extraction are the primary engineering controls. RPE as backup. See our guide on dust and silica for the full picture.

For every substance, the process is the same: obtain the safety data sheet, work through the eight sections, apply the hierarchy of controls, and record your findings. The COSHH feature in The Site Book helps you do this quickly by pulling substance data and control measures from a built-in database, so you are not starting from scratch every time.

Frequently asked questions

Common questions about writing COSHH assessments for construction.

How long should a COSHH assessment be?

There is no fixed length. A COSHH assessment for a single substance used on a straightforward task might be one or two pages. The key is that it covers all the required elements — substance identification, hazard classification, exposure routes, who is at risk, control measures, PPE, emergency procedures, and health surveillance requirements. A well-structured one-page assessment that covers everything is far better than a ten-page document that misses critical details. The HSE wants to see that you have thought through the risks and put sensible controls in place, not that you have produced a lengthy report.

Do I need a separate COSHH assessment for every substance?

Technically, yes — every hazardous substance you use on site needs its own assessment. However, the HSE accepts that you can group similar substances together if they present the same hazards and require the same controls. For example, if you use three different brands of PVA adhesive that all have the same hazard classification and the same safety data sheet recommendations, you could cover them in a single assessment. The important thing is that every substance is accounted for and the controls are specific enough to be meaningful. If in doubt, keep them separate — it takes a few extra minutes but avoids any ambiguity.

Can I use the manufacturer’s safety data sheet as my COSHH assessment?

No. A safety data sheet (SDS) is not a COSHH assessment. The SDS provides generic information about the substance — its hazards, handling recommendations, and emergency measures. Your COSHH assessment must be specific to how you use that substance on your site, taking into account your particular working conditions, the duration and frequency of exposure, who else might be affected, and what controls you are putting in place. However, the SDS is the single most important source document for writing your assessment. You should always start with the SDS and use it to inform your assessment. Keep copies of all relevant safety data sheets alongside your COSHH assessments.

How often do COSHH assessments need to be reviewed?

The COSHH Regulations do not specify a fixed review period, but the HSE expects you to review your assessments whenever there is a significant change — a new substance, a change in the way you work, new information about a hazard, or evidence that your controls are not working (such as someone developing symptoms). As a practical rule of thumb, most health and safety professionals recommend reviewing COSHH assessments at least once a year, even if nothing has obviously changed. If you are working on different projects with different substances, you should be creating project-specific assessments as part of your RAMS for each job.

What happens if the HSE finds I don’t have COSHH assessments?

If an HSE inspector visits your site and you cannot produce COSHH assessments for the hazardous substances being used, you could face enforcement action. This might be an improvement notice, which gives you a deadline to put things right, or a prohibition notice, which stops the work immediately until the issue is resolved. In serious cases — particularly if someone has been harmed — prosecution is possible. Fines for COSHH breaches can be significant, and directors or sole traders can be held personally liable. Beyond the legal consequences, not having COSHH assessments means you genuinely do not know the risks your workers are facing, which puts people’s health in danger.

Do I need health surveillance for workers using cement?

If your workers are regularly exposed to wet cement or cement dust, the answer is almost certainly yes. Health surveillance for cement work typically means regular skin checks — looking for signs of dermatitis, cracking, redness, or irritation on the hands and forearms. This does not necessarily require a doctor; a trained supervisor can carry out basic skin checks using the HSE’s dermatitis checklist, known as MDHS 47. If problems are found, the worker should be referred to an occupational health professional. The purpose of health surveillance is to catch problems early, before they become serious or permanent. It also gives you evidence that your control measures are working — or tells you that they need improving.

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Related guides

COSHH for Builders

A plain-English introduction to COSHH and what it means for your business.

Dust and Silica in Construction

How to control silica dust and protect your lungs on site.

PPE in Construction

What PPE you need, how to choose it, and when to replace it.

Asbestos Awareness for Builders

What every builder needs to know about asbestos in older buildings.

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