Cutting, grinding or drilling concrete, brick or stone releases respirable crystalline silica (RCS), and breathing it causes silicosis, an incurable lung disease. South Africa's occupational exposure limit (OEL) for RCS is currently 0.1 mg/m3, and the Hazardous Chemical Agents Regulations 2021 make you assess exposure, control the dust, monitor the air through an outside authority, and put exposed workers on medical surveillance. Dry cutting without respiratory protection can earn you a prohibition notice on the spot.
The HCA Regulations 2021
The Regulations for Hazardous Chemical Agents 2021 (Government Notice R.280, Gazette 44348, 26 March 2021) replaced the 1995 Hazardous Chemical Substances Regulations. They apply to every employer whose workers may be exposed to hazardous chemical agents (HCAs), and to manufacturers, importers and suppliers of chemicals destined for workplaces. On a building site that covers far more than silica: cement, solvents, adhesives, paints, fuels and treatment chemicals all count.
Silica: the numbers that matter
Silica dust is a Schedule 2 HCA. The current OEL for respirable crystalline silica is 0.1 mg/m3, cut from 0.4 mg/m3 in 2008. Be aware that a new, lower limit may be phasing in: industry commentary in late 2025 discussed implementing a reduced silica OEL for South Africa. Do not assume 0.1 mg/m3 is safe headroom; check the current OEL with the DEL before you design controls around it. For context, concrete is typically 25 to 40 percent silica, so an ordinary chasing or floor-cutting job is squarely inside this regime.
Construction and manufacturing operations that generate silica dust must also submit biannual reports to the DEL with the number of samples taken and the results.
Your duties as an employer
- Hazard assessment: identify every HCA in use and get GHS-compliant Safety Data Sheets for each.
- Exposure assessment: determine likely exposure levels. Air monitoring must be done by an Approved Inspection Authority (AIA), not in-house, on a 24-month cycle for agents with maximum and restricted limits.
- Control hierarchy: eliminate, substitute, engineer (water suppression, local exhaust ventilation), administrate, and only then PPE.
- Dust suppression in practice: wet cutting, on-tool water feeds, and local exhaust ventilation for indoor work.
- Respiratory protection: an FFP3 or P3 half-mask is the minimum for silica work; powered air-purifying respirators for heavy or prolonged exposure.
- Labelling: GHS labels on everything, with Safety Data Sheets available to workers.
Medical surveillance
Workers exposed to HCAs need a pre-placement medical before first exposure, periodic examinations at intervals set by an occupational health practitioner, and an exit examination when they leave. Records are kept for the duration of employment plus the minimum period in the Regulations. For silica specifically, surveillance should watch for early silicosis with spirometry and chest X-rays. A worker who develops silicosis is entitled to compensation under COIDA.
Penalties
Contravening the HCA Regulations is a criminal offence: a fine or up to 6 months imprisonment, plus an additional R500 per day for continuing offences. The bigger cost is the disease itself, which arrives years after the exposure and does not go away.
Worked example: the floor-cutting contractor
A small contractor cuts expansion joints in a warehouse floor. The compliant setup: a wet-cutting diamond blade with continuous water suppression, FFP3 masks for the crew, AIA air sampling within the 24-month cycle for this type of work, exposure records kept, and the crew on annual medical surveillance including spirometry. An inspector who finds dry cutting with no respiratory protection can issue a prohibition notice and stop the job immediately.
Common mistakes
- Dry cutting "just this once". One bad day of exposure is exactly how careers of exposure accumulate.
- A paper dust mask instead of FFP3. Comfort masks do not stop respirable silica.
- Doing your own air monitoring. The Regulations require an AIA.
- No Safety Data Sheets on site. First thing an inspector asks for after the chemicals themselves.
- Treating the 0.1 mg/m3 OEL as fixed. A lower limit may be coming; verify the current figure before relying on it.
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