Silica Dust : A Widespread Hazard

The inhalation of Respirable Crystalline Silica Dust (RCS) is a widespread hazard and significant cause of ill-health in the construction sector. The effective elimination or control of RCS dust is one of three top priorities for HSE now, and in the coming years.

Silica is a natural substance found in most rocks, sand and clay and in products such as bricks and concrete. In the workplace these materials create dust when they are cut, sanded down etc. Some of this dust may be fine enough to reach deep inside the lung, this is known as respirable crystalline silica (RCS) and can cause harm to health. Significant exposure to RCS can cause silicosis and lung cancer.

The greater the level of dust in air, the higher the risk. High dust levels are caused by one or more of the following:


  • High energy tools, cut-off saws, grinders, wall chasers and grit blasters can produce a lot of dust in a very short time.
  • Dry sweeping can make a lot of dust when compared to vacuuming or wet brushing;


  • The more enclosed a space, the more the dust will build up. However, do not assume that levels will be low when working outside with high energy tools;


  • The longer the time dust is created the more dust there will be;


  • Regularly doing the same work day-after-day increases the risks.

The risk is often from exposure over many years and workers may not notice symptoms for a long time. Each exposure to RCS adds up with lungs and airways becoming progressively more and more damaged. The diseases can be made worse by smoking.

But its not just down to those in the construction phase team to eliminate the risk of inhaling RCS.  Designers must act on Silica Dust too. The CDM Regulations 2015 require that individuals or organisations involved in ‘design’ (which includes those specifying materials) must eliminate the RCS risk to construction workers, maintenance workers are others. Where it is not possible to eliminate RCS e.g. by use of silica free products, designers must take steps to reduce (and if not possible) control the risk through the subsequent design process.

The project Principal Designer must ensure that designers comply with this duty to eliminate, reduce and control the RCS risk.  The above HSE guidance should be of great interest to Principal Designers and designers as HSE can take proactive interventions with designers and follow up on the action taken by designers when investigating failures in silica risk management during the project construction phase.

HSE RCS Guidance

The HSE COSHH Essentials series of guidance sets out advice on what to do to eliminate or control exposure to hazardous substances in the workplace.  The construction sector guides on silica can be found here

This information is designed to help duty holders comply with the Control of Substances Hazardous to Health Regulations to prevent or control exposure to respirable crystalline silica (RCS) and protect the health of the workforce.

If you would like further information with regards to Respirable Crystalline Silica (RCS) dust then please contact us.