Construction dust: Dry sweeping
Dry sweeping concrete dust and other building debris can produce high levels of dust. Avoid dry sweeping where possible because this can be high risk. This page tells you how to control the risk and why. You also need to be aware of the general information on construction dust.
What you must do
Follow the Assess, Control and Review model. Pay particular attention to the following things:
Assess
Identify and assess: Dry sweeping concrete dust and other building debris can produce high levels of dust. The risk will depend on how much material you are removing and what it contains. It will be higher risk if it contains silica or wood dust. Anyone breathing in this dust cloud will be affected. You will be at particularly risk if you are dry brushing for longer periods in an enclosed space. Follow the control steps below.
Control
Prevent: Think about limiting the risks before work starts by:
- limiting waste materials and how they are produced during design/ planning
- considering where waste material is created and how frequently it needs removing
- using the correct dust controls when making dust/rubble/debris
Control: Even if you minimise some of the dust this way, you may still need to do some clearing up. Control the risk by:
- Hand tools – damp down and use a brush, shovel and bucket for minor/ small amounts. For regular removal/ site cleaning use a water spray for damping down and a rake/shovel and bucket/wheelbarrow to remove larger pieces.
- On-tool extraction– for finer material use vacuum attachments fitted to an H or M class extraction unit.
- Respiratory Protective Equipment (RPE) – you may also need RPE depending on the location, duration and type of work you are doing. Select RPE with an assigned protection factor of 20 (eg FFP3 disposable mask or half mask with a P3 filter). Fit testing is needed for tight fitting masks.
Review
Supervise: Ensure controls are properly used and RPE is worn correctly. Anyone using tight fitting masks also needs to be clean-shaven and face-fit tested.
Maintain: Check the extraction unit is correctly working on at least a weakly basis. Change filters as recommended by the supplier.
Monitor: Decide if you need a health surveillance programme . This depends on the amount and type of dust people are breathing. You may need competent advice for this from an occupational health professional. See:
- Health monitoring for chronic obstructive pulmonary disease G401
- Health surveillance for work related asthma G402
- Health surveillance for those exposed to respirable crystalline silica G404
What you should know
Clearing up may seem low risk. However, dry brushing can push large amounts of dust into the air. Watch the graph in the video clip below. This shows how much silica is created when dry brushing concrete dust. The Workplace Exposure Limit for silica is 0.1 mg/m3 when averaged over 8 hours. The work quickly produces high peak exposures of around 1-2 mg/m3. The dust lamp also shows how much of this fine respirable dust gets into the air. This will re-settle sometime later and the floor will have to be cleaned again.
Now watch the video below. The graph shows a dramatic drop in the amount of silica when using the correct extraction unit. The dust is also quickly removed and there is no resettling later on. Because of this, RPE would not normally be needed as well in this situation. It was used while filming as an example of good practice.