Hazards and control measures
Dust hazards and control measures
Silica dust, wood dust and the other hazardous substances on site, from resins and solvents to wet cement and welding fume. Who gets hurt, the workplace exposure limit for silica, and the control measures COSHH expects, in order, with a worked example from a completed RAMS.
What are the main dust hazards on a construction site?
The main dust hazard is respirable crystalline silica, made when concrete, mortar, brick, block and stone are cut, drilled or ground, followed by wood dust. Breathing it regularly can cause lung cancer, silicosis, COPD and asthma, and HSE believes over 500 construction workers die from silica dust every year. COSHH expects you to avoid or substitute the material first, then control the dust at source with water or on-tool extraction, and only then rely on a face-fit tested mask.
Last updated . Facts checked by the SiteSurvey team on 24 October 2026 against HSE: Construction dust, HSE: Control of exposure to silica dust (INDG463), HSE: Cement and HSE: Construction dust FAQs.
Where dust and hazardous substances show up
Silica is in most of the materials a building is made from. HSE puts sandstone above 70 per cent crystalline silica and mortar and concrete at 25 to 70 per cent, and brick, block, tile and granite all contain it. Cutting, drilling, grinding and polishing those materials turns the silica into a fine respirable dust that hangs in the air long after the visible cloud has settled. A groundworker on a cut-off saw, an electrician drilling through a block wall, an installer drilling anchor holes in a warehouse slab and a mason dressing stone are all making it. Cutting and sanding timber makes wood dust, and dry sweeping puts all of it back into the air.
Dust is not the only substance on site. Two-part resins and adhesives, solvents in paints and cleaners, isocyanates, welding fume and wet cement are all substances hazardous to health, and each needs its own assessment from the safety data sheet. Wet cement is strongly alkaline: trapped against the skin under a glove, in a boot or under a knee, it can cause a serious burn, and repeated contact causes dermatitis that can become an allergy for life.
Who is harmed, and how
HSE says over 500 construction workers are believed to die from exposure to silica dust every year. Regularly breathing construction dust can cause lung cancer, silicosis, chronic obstructive pulmonary disease and asthma, diseases that cause permanent disability and early death. None of them can be undone once the lungs are damaged, which is why the control has to happen at the time the dust is made, not after.
The people most exposed are the ones holding the tool, but they are not the only ones. Dust drifts to the next trade, to the client's staff and into occupied rooms, which is why the worked example on this page keeps the drilling dust out of a working warehouse's picking aisles. Skin is harmed directly: a cement burn can need a skin graft in the worst cases, and allergic dermatitis can end a career working with cement.
What the law expects
The Control of Substances Hazardous to Health Regulations 2002 set an order. First ask whether the hazard can be removed: a material with no silica or a lower silica content, a product with a lower hazard rating, or a design that avoids cutting on site. Where the exposure cannot be avoided, limit the dust at source, then capture it with water suppression or on-tool extraction connected to a suitable vacuum. Respiratory protection comes only where the risk cannot be controlled by those engineering controls alone, and for high dust work with silica or wood HSE advises an FFP3 mask, fit tested to the wearer.
For silica the controls must keep exposure below the workplace exposure limit of 0.1 mg/m3 of respirable dust, averaged over eight hours. The equipment that does the controlling is maintained, the crew are trained and told the risks, the controls are monitored, and health surveillance is arranged where appropriate. Washing facilities with warm water and soap deal with what gets on the skin. In SiteSurvey, the RAMS template records each substance and the controls for it, and the Suggested controls list follows the same order, with a warning when only a mask is ticked.
Suggested controls
Hazardous substances and dust: control measures, most effective first
These are the 6 controls the SiteSurvey RAMS and risk assessment forms offer for this hazard as a tick list, grouped by their level in the hierarchy of controls. They are a starting point from HSE guidance, not an assessment of your job: tick what applies and say how it works on your site. If only personal protective equipment is ticked, the form says so. How suggested controls work and the hierarchy of controls explained.
Swap the hazard for something less harmful: a quieter tool, a cold-applied method, a smaller pack.
- A less harmful product chosen where one does the job
Keep people away from the hazard with a physical measure: a guardrail, a barrier, extraction, isolation.
- Dust suppressed at source with water or on-tool extraction
Change the way the work is done: a permit, a check, training, supervision, timing.
- COSHH assessment for every product on this job, kept with the RAMS
- Work in the open air or with ventilation, and skin contact avoided
- Washing facilities available and used before eating
Protect the person as the last line: a harness, hard hat, gloves or respirator. Never the only control.
- Respiratory protection face-fit tested and gloves suited to the product
Offered to: every type of work in the RAMS form.
Try it
Build the controls for hazardous substances and dust
Tick the controls you would put in place, see which levels of the hierarchy they reach, and score the risk before and after. Or fill in the example from a completed RAMS to see how one crew did it.
Interactive
Try it: hazardous substances and dust
Works the same way as the RAMS form. Nothing you tick is saved or sent anywhere.
Your controls, by level
- Eliminateno control at this level for this hazard
- Substitutenot ticked
- Engineeringnot ticked
- Adminnot ticked
- PPEnot ticked
Nothing ticked yet.
3. Score the risk with these controls
What the law says
- Control of Substances Hazardous to Health Regulations 2002
- Assess the substances, prevent exposure or substitute where you can, otherwise control it in order of priority with PPE last, keep below the workplace exposure limits and as low as reasonably practicable for carcinogens such as silica (regulation 7).
- Management of Health and Safety at Work Regulations 1999, regulation 3
- The suitable and sufficient risk assessment that identifies the dust and substances on the job and the controls.
- Construction (Design and Management) Regulations 2015
- Designers and contractors plan out hazards such as cutting on site where they can, and the principal contractor manages what is left through the construction phase plan.
Worked example
Hazardous substances and dust in a completed RAMS
The hazard entry exactly as it was recorded in one of our completed example RAMS: the controls ticked from the list, how they apply on that job, and the score before and after the further action.
Construction and building work
Castlemead Logistics, Nottingham: pallet racking installation, aisles 12 to 17
- Hazard
- Hazardous substances and dust: Floor anchor holes at every frame foot (about 430 holes), and the anchor resin cartridges
- What could happen, and to whom
- Silica dust from drilling the concrete slab, breathed in by the driller and spread into the client's picking aisles, and skin and eye contact with the two-part anchor resin. The crew, and the client's staff if dust drifted out of the zone.
- Controls ticked
- A less harmful product chosen where one does the job
- COSHH assessment for every product on this job, kept with the RAMS
- Dust suppressed at source with water or on-tool extraction
- Work in the open air or with ventilation, and skin contact avoided
- Washing facilities available and used before eating
- Respiratory protection face-fit tested and gloves suited to the product
- How they apply on this job
- Every anchor hole is drilled with the on-tool extraction shroud connected to an M-class vacuum, so there is no dry drilling and no visible dust in the aisle; the vacuum bag is sealed and binned as hazardous waste. The drillers wear FFP3 masks, face-fit tested in 2026 for both, during drilling and hole cleaning with the blow-out pump. The styrene-free vinylester resin was chosen over the epoxy-acrylate we used to use because it has a lower hazard rating; its COSHH assessment COSHH-TSS-021 and safety data sheet are in the RAMS folder. Nitrile gloves and eye protection worn when gunning resin, cartridges capped between holes, and spent cartridges bagged. The crew wash in the dock welfare block before breaks.
- Risk with these controls (likelihood x severity)
- 3 x 3 = 9 (Medium)
- Further action
- M-class vacuum and spare bags on the hire order; vacuum filter checked and face-fit records for K. Osei and A. Hussain put in the folder before drilling starts. Owner: P. Danvers.
- Residual risk
- 1 x 3 = 3 (Low)
A fictional job, filled in as a worked example. The form and the report are real.
It also appears in felt roof renewal on a school sports hall, foundations and drainage for a house extension, distribution board replacement in an occupied office, clearing and deep cleaning a void flat, pump replacement in a foul water chamber and welding heating pipework in a hospital plant room. All eleven completed RAMS.
Templates that cover it
Hazardous substances and dust: common questions
Is a dust mask enough on its own?
No. COSHH puts respiratory protection last, after avoiding the dust and controlling it at source, and in addition to those controls. A mask only works if it is the right type, fits the wearer's face and is worn the whole time the dust is being made. For high dust work with silica or wood, HSE advises an FFP3 mask, and the wearer should be face-fit tested.
Does water suppression have to run all the time?
Yes. HSE says there must be enough water for the whole time the work is being done, so a saw that runs dry halfway through a cut is making silica dust again. Check the bottle or supply before the job starts and keep it topped up. The same goes for on-tool extraction: the vacuum must be the right class and the filter and bag in good order.
Why is dry sweeping a problem?
Dry sweeping puts the fine dust back into the air, and HSE says it creates much more dust than vacuuming or wet brushing. Clear up with a suitable vacuum or by damping down first. Treat the cleaning as part of the dusty task, with the same mask, rather than as a separate job for whoever is nearest.
What do we do about wet cement on the skin?
Wash it off as soon as possible with clean running water and soap, and use eyewash if it gets in the eyes. Wear long or tight-fitting waterproof gloves rated for alkalis so cement cannot get trapped inside, and waterproof trousers over boots if kneeling in it. Burns from wet cement can be serious because they often go unnoticed until the end of the shift.
Last updated . See every hazard in the library.
Write the RAMS with these controls already listed.
Pick the hazard, tick its controls, score it and brief the crew, on a phone or laptop. The report goes to the client as one PDF.