8 March 2023
Respirable crystalline silica (RCS) is created by a range of manufacturing processes – from working stone, to kitchen worktops, and even distressing jeans. It is a particular problem in foundry practices, where green sand is used in metal moulds. The dust produced by this material is not visible to the naked eye. The particles are 100 times smaller than normal sand, making them easily inhaled. Once the particles penetrate the lungs, they stay there.
In foundry operations, workers who clean casting moulds made of green sand are at risk of breathing in high concentrations of RCS. Long-term exposure to RCS can lead to a number of life-limiting health conditions, such as asthma, bronchitis, COPD, silicosis, and even lung cancer.
Silicosis forms scar tissue in the gas exchange tissue of the lungs, which inhibits oxygen uptake into the bloodstream. The British Occupational Hygiene Society estimates that 500 workers die in the UK every year from silicosis, with those infected by Covid-19 being more vulnerable. Silica inhalation is also linked to over 4,000 deaths per year in the UK from COPD.
The health risks are so severe that in 2020, an All-Party Parliamentary Group on respiratory health published a report naming silica dust the next asbestos.
It is vital to first assess the level of workers’ exposure to dust inhalation to ensure that adequate control measures are devised. The assumption of compliance is not enough; measures are required to prove that the risks have been adequately assessed.
RCS is classed as a carcinogen (when generated as a result of a work process), so exposure must be reduced to as low levels as is reasonably practical. The Workplace Exposure Limit (WEL) is low at 0.1mg/m3 (8hr time-weighted average (TWA)), which must not be exceeded.
Our trained and accredited Occupational Hygienists have many years of experience in workplace air monitoring. If you need help with your workplace processes, contact us.