Floor Levelling Compound / Self-Smoothing Screed Dust
COSHH assessment
A COSHH assessment for floor levelling compound / self-smoothing screed dust on a UK construction site: what it does to people, how it gets into them, the controls that stop it, the PPE for what is left, and what to do when it goes wrong. Copy it into your assessment and change what does not fit your job.
Hazards to health
Alkaline dust, irritant dermatitis and chemical burn (pH 11-12). Some products contain crystalline silica, see COSHH-002. Casein-based products (rare), protein sensitiser, can cause asthma.
Routes of exposure
Inhalation, Skin contact, Eye contact
Control measures
- Pre-blended bagged products to reduce dust.
- Mix in ventilated area with mixer-paddle dust hood.
- Slit-and-pour bag opening into mixer to limit airborne release.
- Damp clean-up, no dry sweeping.
- Read SDS for silica content; if present, follow COSHH-002 controls.
- Skin checks under health surveillance.
PPE for what is left
- FFP3 dust mask when mixing or pouring (FFP2 minimum for low-silica), Splash goggles, Nitrile gloves, Knee pads, Long sleeves and trousers
Emergency procedures
- Inhalation: fresh air, A&E if persistent cough.
- Skin: rinse with cool water 20 mins, A&E for any burn.
- Eyes: irrigate 20 mins minimum, urgent A&E (alkaline burns penetrate fast).
Questions people ask
Do I need a COSHH assessment for floor levelling compound / self-smoothing screed dust?
If the substance is hazardous to health and your work exposes people to it, yes. The Control of Substances Hazardous to Health Regulations 2002, regulation 6, require a suitable and sufficient assessment before the work starts, with the significant findings recorded if you employ five or more. The safety data sheet is an input to the assessment, not a substitute for it. Guidance, not legal advice.
What is the difference between a safety data sheet and a COSHH assessment?
The data sheet is the manufacturer describing the product in general. The assessment is you describing how your people use it on your job: how much, how often, for how long, in what ventilation, with what controls. Two firms using the same tin can have very different assessments.
What is a WEL?
A Workplace Exposure Limit, the maximum airborne concentration averaged over a reference period, set in HSE document EH40. Where one applies to this substance it is stated in the hazards above; where it does not, the duty to reduce exposure so far as is reasonably practicable still stands.
Is PPE enough?
No. COSHH puts PPE last: eliminate the substance, substitute for something less harmful, control at source with ventilation and enclosure, then organise the work to reduce exposure, and only then PPE for what is left. An assessment that jumps straight to gloves and a mask is the kind an inspector questions. Guidance, not legal advice.
How often should it be reviewed?
When the product, the method, the quantities or the people change, if there is any sign the controls are not working, and at least every year or so regardless. Health surveillance may be required where exposure could cause an identifiable disease, such as dermatitis or occupational asthma.
The COSHH assessment writes itself
Pick the substance in the SiteLynx RAMS editor and the COSHH assessment fills in with the hazards, controls and PPE, alongside the HAVS and noise assessments for the tools you chose. Signed on site on a phone. 14 days free.
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