Respirable Crystalline Silica – get in the know

So, what is it, and why does it matter?

Silica is a natural substance found in most rocks and is the most abundant compound in the earth’s crust. It is also present in sand, clay, and products such as bricks, concrete, and stone.

In the workplace these materials create dust when they are cut, drilled, or sanded down etc. Some of this dust may be fine enough to reach deep inside the lungs and may contain respirable crystalline silica (RCS), and in particular quartz particles, that can cause harm to health. Exposure over a long period of time can cause fibrosis (hardening or scarring) of the lung tissue with a consequent loss of lung function.

Key conditions that can arise include silicosis, chronic obstructive pulmonary disease (COPD), kidney disease, and is associated with the development of lung infections, autoimmune disorders, and cardiovascular impairment. Sufferers are likely to have severe shortness of breath and may find it difficult or impossible to walk upstairs or even short distances. The effect continues to develop after exposure has stopped and is irreversible.

Therefore, it is imperative that a thorough monitoring procedure should be implemented to prevent unnecessary serious illnesses of those who work in this industry.

“An estimate from the Cancer Burden Study of the number of deaths from lung cancer associated with exposure to RCS shows there are around 600 deaths per year with 450 of these occurring from exposures in the construction sector alone (UK figures).” HSE

How does exposure occur?

Research from Imperial College London suggests that around 900 new cases of lung cancer each year in Britain can be attributed to past exposure to silica dust in construction, granite and stone industries, and various industrial processes. High risk industries include stone working, brick manufacturing, metal casting and foundries, cement production, mining, quarrying and demolition.

Common scenarios where people can be exposed include:

• Breaking, crushing, grinding, or milling silica-containing material such as concrete
• Moving earth, e.g. excavating, mining, quarrying, or tunnelling
• Drilling, cutting, blasting, chiselling or sanding silica-containing material
• Using silica, sand, or silica-containing products in the manufacturing process of glass and other non-metallic mineral products

Health and safety institutions in the UK and around the world, are encouraging workers within these industries to ensure key practices are in place to reduce and monitor exposure to prevent workers from suffering the irreparable damage this disease causes to the lungs.

How can workplaces minimise or prevent exposure?

On a group level - in a factory or workshop environment, the best strategy is to use engineering controls like enclosures or extraction hoods, and local exhaust ventilation to extract the contaminated air at the point it’s produced. Using water suppression on fixed machinery, and by improvement of housekeeping standards by using vacuums fitted with HEPA filters or wet cleaning methods are also effective methods of control.

On an individual level - where work with hand-held power tools generates dust, the best strategies are to use localised ventilation on the tool or suppress the dust using water spray systems.

As a last resort - in all situations, if it’s not possible to adequately control airborne silica dust using engineering solutions, and air sampling data shows that there is still an unacceptable level of dust, then operatives should use personal respiratory protection equipment (RPE).

Exposure monitoring and analysis

RPS is uniquely positioned to design a fully integrated respirable crystalline silica monitoring and laboratory analysis service, which supports clients to understand, evaluate and manage occupational exposure to RCS. Our service can be tailored in response to each client’s needs, to assist them to meet their (COSHH) regulatory requirements. The benefit of these combined services is the time and cost efficiencies you will gain, compliance with prescribed occupational exposure limits, control of the workplace environment and working methods, and staff education will help companies achieve the required level of workers’ protection.

Exposure limits:

The current Workplace Exposure Limit (WEL) in the UK is 0.1 mg/m³ [see link]. If you are unsure whether your employee exposure exceeds the levels laid down in the COSHH regulations, then it would be appropriate to undertake exposure monitoring.

Workplace analysis:

RPS provides UKAS accredited analysis, as well as the provision of suitable media to specifically look for Respirable Crystalline Silica, including quartz and cristobalite, in line with MDHS 101/2 and MDHS 14/4 methods.