Doctors in the UK are raising awareness of the silicosis risk to engineered stone workers and calling for the government to ban the material.
Engineered stone is made from quartz pieces held together with a resin binder. The resulting material looks similar to natural stone and has become increasingly popular for use in kitchen and bathroom worktops.
Engineered stone contains substantially more crystalline silica than natural stone – over 90%, compared with less than 45% in granite. The high silica content puts workers at greater risk of developing silicosis.
What is silica?
Silica is a mineral found in stone and other construction materials, including:
- Engineered stone
- Granite and other minerals
- Soil
- Sand
- Concrete
- Mortar
Dust is generated during common tasks such as cutting and polishing materials. The dust is made up of small particles that become airborne and cause a respiratory hazard.
Respirable crystalline silica (RCS) is a term for the fine dust that gets deep into the lungs when inhaled. RCS dust is too fine to see with regular lighting and inhaling just a small amount can do a lot of damage.
Silicosis and other health effects
Silicosis is an incurable lung disease caused by inhaling silica dust, usually over a period of several years. The condition is debilitating and potentially fatal.
The main symptoms of silicosis are a persistent cough and shortness of breath, along with feeling weak and tired. Symptoms become more severe as the condition progresses. Walking and climbing stairs can be very difficult and silicosis patients may ultimately be confined to their house or bed.
Silicosis can also increase the risk of developing other serious and potentially life-threatening conditions, including:
- Chronic obstructive pulmonary disease (COPD)
- Lung cancer
- Tuberculosis (TB) and other chest infections
- Pulmonary hypertension
- Heart failure
- Kidney disease
Silicosis arising from engineered stone exposure
Doctors are reporting the first UK cases of silicosis resulting from exposure to engineered stone dust. All cases involved workers dry cutting and polishing worktops without adequate control measures.
Some had worked with engineered stone for just 4 years before being diagnosed with silicosis, demonstrating how quickly the condition can develop as a result of engineered stone dust inhalation. Numbers are likely to increase as more cases are identified and linked to past exposure.
Protecting workers
The high silica concentration and fast development of silicosis following exposure highlights the need for action. Experts are urging the British government to consider banning engineered stone, following Australia who banned the material in July 2024. In the meantime, effective control measures are required to reduce exposure and protect workers against silicosis.
Exposure limits
The UK/EU exposure limit for silica is 0.1mg/m3 over an 8-hour period. This image illustrates 0.1mg/m3 of silica dust compared to a penny coin. UK and EU law requires companies to ensure exposure is well below the amount shown here. USA and Australia limits are lower. The North American Permissible Exposure Limit (PEL) is 50µg/m3 and Australia’s WEL is set at 0.05mg/m3.
It is important to remember that there is no ‘safe’ limit – inhaling any amount of silica dust is harmful and exposure should be reduced as much as possible.
Control measures
To prevent silicosis in engineered stone workers, silica dust exposure must be minimised through effective engineering controls and work practices.
Use wet methods to cut and work materials. Install ventilation, extraction and dust suppression to reduce the amount of RCS dust in the air. Ventilation equipment must be regularly cleaned and serviced to ensure it is working properly. Make sure that proper on-tool dust suppression is used. Tools with water directed at the top of the blade are only intended to provide cooling, not dust control. Water must be directed at the cutting site to be effective.
Even cleaning up can contribute to silica dust exposure. Dry sweeping or dry brushing increases the amount of RCS in the air. Use wet sweeping methods or HEPA-filtered vacuums to control dust levels when cleaning up. Compressed air should not be used to clean clothing or surfaces as this causes airborne dust to become airborne again, allowing it to be inhaled.
Respiratory protective equipment (RPE)
After implementing other control measures, respiratory protective equipment (RPE) reduces exposure further. RPE must offer a UK Assigned Protection Factor (APF) of at least 20, with a high-efficiency particulate filter.
RPE options include:
- FFP3 disposable respirator
- Half mask with P3 filters
- Full face mask with P3 filters
- Powered respirator with TH2PSL / TM2PSL performance rating or above
Tight-fitting respirators must be fit tested to ensure protection. This includes disposable respirators, half masks and full face masks. Each wearer must be fit tested in their specific model and size of mask to make sure they can achieve a good seal. Wearers of tight-fitting RPE also need to be clean-shaven in the area of the face seal. Find out more about respiratory protection and facial hair.
Loose-fitting powered air purifying respirators (PAPR) do not rely on a seal to provide protection. Bearded workers must consider a loose-fitting PAPR to be sufficiently protected. Learn more about loose-fitting respirators.
Regular maintenance is essential to ensure RPE continues to provide the intended level of protection. Respirators are supplied with instruction manuals that detail cleaning and maintenance procedures, which may include disassembly, cleaning, inspection and replacing exhausted parts.
Training is also vital. To make sure RPE is used and maintained correctly, workers should be trained in how to read markings and expiry dates, change filters, and conduct pre-use and fit checks. For powered respirators, training should cover battery life and charging.
Silica dust inhalation is highly dangerous even in small amounts. The increased silica content in engineered stone means an increased risk to workers. Mitigation through engineering and workplace control measures is the most effective way to limit exposure and protect against silicosis.
Dust levels should be reduced as far as possible before introducing RPE. Respirators must be correctly fitted and well-maintained. Fit testing is key to ensure tight-fitting respirators can properly protect the wearer. Those with facial hair require a loose-fitting PAPR device.