Workplace exposure standard for respirable crystalline silica

What is RCS? 

Crystalline silica is found in sand, stone, concrete and mortar. It is also used to make a variety of products, including engineered stone for kitchen and bathroom benchtops, bricks and tiles. 

Respirable crystalline silica (RCS) is generated in workplace mechanical processes such as crushing, cutting, drilling, grinding, sawing or polishing of natural stone or man-made products that contain silica. RCS can penetrate deep into the lungs and can cause irreversible lung damage.

What is a WES? 

A workplace exposure standard (WES) represents the concentration of an airborne hazardous chemical (for example, respirable crystalline silica) within a worker’s breathing zone that should not cause adverse health effects or undue harm.

Compliance with the WES is required under Commonwealth, state and territory WHS laws.  

What does the RCS WES mean for you? 

The WES for RCS is 0.05 mg/m³ (eight-hour time weighted average). The WES must not be exceeded.

If you are a person conducting a business or undertaking (for example, an employer or small business owner), you may need to implement control measures or make changes to your workplace procedures so that the WES for RCS is not exceeded. 

This could include engineering controls (such as a combination of local exhaust ventilation (LEV) or on-tool dust extraction and wet cutting methods), administrative controls and respiratory protective equipment (RPE).  

Here are five things you can do to help protect your workers from exposure to RCS: 

1. Assess the risk of silica dust at your workplace.  
2. Implement control measures to minimise your workers’ exposure to RCS.  
3. Arrange for air monitoring if you are unsure how high the airborne RCS levels are at your workplace.  
4. Talk to your workers and any health and safety representatives (HSRs) about the risks of RCS, the control measures in place at your workplace to manage risks and ensure workers are not exposed to levels above the WES, and any training your workers might need. 
5. Implement a health monitoring program if there is RCS at your workplace, including workers who generate RCS or those who work near it.  

What do my workers need to know about the RCS WES? 

Talk with your workers about the adverse health effects that can occur from exposure to RCS, why you might conduct air and health monitoring, and any changes to the control measures you are looking to make at your workplace.  

Supporting information

• See the workplace exposure standard for respirable crystalline silica
• See the Guide for working with silica and silica containing products
• Contact your WHS regulator.