Handheld power saws
Using a handheld power saw (also called a cut-off saw or quick cut) to cut masonry, concrete, stone or other silica-containing materials can generate respirable crystalline silica dust. When inhaled over time, the small particles of silica dust can irreversibly damage the lungs.
The steps below outline the exposure controls needed as per appendix 4 of the Managing respirable crystalline silica in construction and manufacturing of construction elements code of practice 2022 (PDF, 1.71 MB) when using handheld power saws.
Step 1: Use suitable engineering controls
Engineering control options (one of the following two controls must be used)
- Wet cutting with an integrated continuous water feed on the blade.
- A commercial dust collection system which meets or exceeds the minimum air flow requirements recommended by the tool manufacturer and rated to either M-Class or H-Class.
Wet cutting
Many handheld power saws come equipped with an integrated water delivery system which delivers a continuous stream of water onto the blade where it wets the material being cut and reduces the amount of dust generated. A constant water supply can come from a hose connected to a tap or construction site water supply. Water flow rates must be equal to or better than that recommended by the manufacturer.
The saw must be operated and maintained in accordance with the manufacturer’s instructions to minimise dust emissions.
- Check hoses are securely connected and not cracked or broken.
- Adjust nozzles so water goes to the blade and wets the cutting area.
- Inspect the saw blade to ensure it is in good condition and does not show excessive wear.
- Maintain and operate the saw’s dust-control equipment based on the manufacturer’s instructions.
- Clean up slurry produced while wet before it dries and releases silica dust into the air. Wet slurry can be cleaned up using shovels or a wet vacuum.
Wet cutting indoors or in enclosed areas
Wet cutting indoors or in enclosed areas may not reliably keep silica dust exposures low. Extra ventilation or a means of exhaust may be needed to reduce visible airborne dust. Extra ventilation can be supplied by:
- exhaust trunks
- portable exhaust fans
- air ducts
- other means of mechanical ventilation.
Dust collection systems
A commercial dust collection system can be used to capture the dust generated by a handheld power saw. A person conducting a business or undertaking (PCBU) can comply with Appendix 4 of the Code by using a saw with a dust collection system with a M or H-class rating. The air flow provided by the system must be equal to or greater than the flow required by the manufacturer.
Step 2: Select appropriate respiratory protective equipment (RPE)
The type of RPE you will need depends on:
- what type of engineering controls you are using
- how long the worker is going to do the task during the shift
- where the work is being undertaken.
RPE is not required when wet cutting outdoors for less than four hours but is required in all other circumstances. Half face reusable or disposable RPE has a minimum protection factor (MPF) of 10.
| Engineering control used | Time spent doing task during shift | |
|---|---|---|
| Equal or less than 4 hours | Greater than 4 hours | |
| Wet cutting |
Outdoors RPE not required |
Outdoors P1 or P2 filtered RPE with a MPF 10 required |
|
Indoors / enclosed area P1 or P2 filtered RPE with a MPF 10 required |
Indoors / enclosed area P1 or P2 filtered RPE with a MPF 10 required | |
| Dust extraction |
Outdoors P1 or P2 filtered RPE with a MPF 10 required |
Outdoors P1 or P2 filtered RPE with a MPF 10 required |
|
Indoors / enclosed area P1 or P2 filtered RPE with a MPF 10 required |
Indoors / enclosed area P1 or P2 filtered RPE with a MPF 10 required | |
For tight fitting RPE, workers must be fit-tested to the specific make and model before using it. See section 7.6 of the Code (PDF, 1.71 MB) for more information on fit-testing and other requirements for using RPE.
Health monitoring
A PCBU must provide health monitoring to a worker if their tasks require them to wear RPE 30 times or more in 12 months.