Respirable crystalline silica (RCS) is one of the most serious long-term health hazards in construction and manufacturing. This fine dust, generated when working with concrete, stone, or brick, can penetrate deep into the lungs and cause irreversible damage. Understanding the risk and control requirements is essential for any responsible employer or contractor.

Where Silica Dust Comes From

RCS is released during activities such as drilling, cutting, grinding, or crushing materials that contain crystalline silica. Even short-term exposure can add up over time to exceed workplace limits. Dust clouds settle on surfaces and can be re-suspended, meaning risk remains long after work ends.

Health Effects and Exposure Limits

When inhaled, respirable silica particles can reach the alveoli where they cause inflammation and fibrosis. Prolonged or repeated exposure leads to silicosis, an incurable lung disease. RCS is also classified as a human carcinogen. In the UK, the Workplace Exposure Limit for respirable crystalline silica is 0.1 mg/m³ (8-hour TWA). Similar thresholds apply under OSHA’s PEL in the United States.

Control Measures

Effective control follows the hierarchy: eliminate, substitute, engineer, and protect. Use wet cutting methods, local extraction, or enclosure to reduce generation at source. Always use an M or H class vacuum for clean-up, with HEPA filtration. Workers should wear properly fitted respirators, ideally FFP3 rated, and undergo health surveillance as required by COSHH.

Compliance and Responsibility

Employers must assess exposure and document control methods in a written risk assessment. Routine monitoring demonstrates that control measures remain effective. Worker training, record keeping, and maintenance logs show due diligence during inspections.

Practical Takeaways

• Identify all tasks generating RCS and assess risk
• Use wet or enclosed methods wherever possible
• Select M or H class vacuums with HEPA filters for clean-up
• Provide fit-tested respiratory protection
• Monitor exposure and maintain health surveillance records

Managing respirable crystalline silica properly protects lives and ensures compliance with both health and legal obligations.