A huge number of workers are exposed to respirable crystalline silica every day. We have been working with clients and delivering training for many years to help our clients and the industry understand the risks. The image to the right shows you the maximum you can be exposed to in a whole day and still remain below the Workplace Exposure Level (WEL) of 0.1 mg/m³
Silica is everywhere — in stone, concrete, bricks, clay, engineered stone, and mo
re. But when materials containing crystalline silica are cut, ground, or disturbed, they can generate respirable crystalline silica (RCS): an extremely fine dust that can penetrate deep into the lungs.
What many don’t realise is that lung damage from RCS exposure often develops before symptoms appear. That’s why health surveillance is a vital tool — not instead of risk control, but to complement it. The HSE’s COSHH Essentials guidance G404 gives clear direction on how employers should plan, perform, record, and act on health surveillance for workers exposed to RCS.
The Health Risks from RCS
The G404 guidance highlights the key diseases linked to RCS exposure:
- Silicosis — irreversible scarring of lung tissue, in severe cases progressing even after exposure stops.
- Chronic Obstructive Pulmonary Disease (COPD) — a long-term condition that gradually impairs breathing.
- Lung cancer and other diseases — RCS is classified as a carcinogen.
Typical early symptoms include shortness of breath, persistent cough (with or without phlegm), frequent chest infections, and wheezing. Because symptoms can be subtle or develop slowly, letting them go unreported or undetected may allow irreversible damage to advance.
When Should Health Surveillance Be Considered?
According to G404, health surveillance should be considered (and sometimes required) when:
- Workers are regularly exposed to RCS dust and silicosis is a plausible outcome.
- There have been prior cases of ill health in the workplace or industry.
- Respiratory protective equipment (RPE) is a relied-upon control measure.
- Industry or process evidence indicates a risk.
High‐risk sectors include stone and concrete work, construction (cutting, drilling, breaking masonry), quarrying, foundries, ceramic and slate processing, and worktop installation.
Health surveillance must not replace risk assessment or control measures; rather, it is a safety net to detect ill health early and feed back into improving controls.
What Should a Proper Health Surveillance Scheme Include?
A robust scheme — designed in conjunction with a suitably competent occupational health professional — should contain:
- Baseline assessment as soon as possible after exposure begins (ideally within six weeks) to establish a “before exposure” reference.
- Ongoing periodic assessments at intervals advised by the occupational health professional.
- Questionnaires focused on respiratory symptoms and history.
- Lung function tests (spirometry) to measure breathing capacity.
- Chest X-rays or further imaging, when recommended (particularly in cases of suspected overexposure).
- Interpretation of results at both individual and group levels to spot trends or common issues.
If any signs of work-related lung disease are identified, the employer must act — review the risk assessment, revise controls, and possibly redeploy affected workers to less hazardous roles.
Record Keeping & Reporting
To ensure accountability and long-term traceability, G404 mandates that health records be kept for at least 40 years from the last entry.
Records should include:
- Worker identity (name, address, NI number)
- The processes/products the worker handles
- Date exposure began, frequency, and duration
- The PPE used, if any
- Results of health surveillance tests
Workers should also be encouraged to retain their own copies of their health results in case they change jobs.
Key Takeaways for Employers & Safety Practitioners
- Don’t wait for symptoms — lung damage can progress before workers notice issues.
- Implement health surveillance only alongside strong controls (like dust suppression, ventilation, proper PPE).
- Work with competent occupational health professionals to design suitable surveillance schedules.
- Regularly review and act on surveillance findings — they should inform your risk assessments and control measures.
- Maintain detailed and long-lasting records, and allow worker access to their own data.
