Respirable Crystalline Silica (RCS)

Control Measures

Occupational exposure to respirable crystalline silica (RCS) dust can occur in many industries including construction, quarrying and manufacturing. Certain activities such as cutting, sanding, abrading, crushing and sweeping are associated with higher levels of dust.

When working with materials containing silica first consider if it is possible to complete the task without creating a risk to health. It may be possible to substitute the material with a lower RCS content.

Sand blasting with sand (silica) is not permitted and a silica-free abrasive should be used as a substitute.

Where exposure cannot be avoided it must be adequately controlled. Control measures may involve the use of engineering controls such as local exhaust ventilation systems (LEV) designed to take harmful dust away from a person’s breathing zone.

Use of a hand-held cut-off saw with a water suppression attachment is a good example of an effective engineering control. More information on controlling the risks from using cut-off saws is available within the Health and Safety Executive leaflet Using cut-off saws - A guide to protecting your lungs (INDG461).

Control measures may be very straightforward such as not using compressed air to remove dust from clothing or other surfaces which should not be permitted. Other examples may include changes to the process or the way the task is carried out such as:

Using water to supress dust when cutting.
Using vacuums with high efficiency filters instead of sweeping.
Using LEV when cutting, sanding, abrading.

Where LEV is used, employers should ensure that employees are trained on how to operate the equipment and that it has been suitably maintained and thoroughly examined so as to ensure it is performing as intended. Further information on LEV systems is available within HSE guidance entitled Controlling airborne contaminants at work: A guide to local exhaust ventilation (LEV) HSG258.

Engineering controls may be need to be used in combination with respiratory protective equipment (RPE) e.g. operators wearing suitable respiratory protection in combination with water suppression techniques when operating stone cutting equipment.

Where a respirator is needed:

The right type of respirator should be provided for the task being performed.
Workers must have had a face-fit test to ensure tight-fitting respirators fit properly and be clean shaven for this type of respirator to work effectively.
Workers should be trained to use, check and clean the respirator.
The filters or disposable respirators should be changed regularly.
The equipment should be stored in a clean, dust-free place.
If any defects are found, or the respirator does not fit, is dirty or its filter is old, it should be replaced.

Further information on preventing lung diseases caused by exposure to silica at work can be found within the HSE publication Control of exposure to silica dust, A guide for employees (INDG463).

Several videos have also been produced that clearly demonstrate general principles for controlling RCS in the workplace.

Time to clear the air! Using cut-off saws for cutting kerbs and flag paving (HSE)
Protecting Workers from Silica Hazards in the Workplace (OSHA)

Detailed industry guidance on controlling the risks associated with RCS dust is available at the following links:

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