Walk-behind saws
Using a stationary masonry saw to cut bricks, concrete blocks, pavers, tiles 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.
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 walk-behind saws controls are explained below.
Step 1: Use suitable engineering controls
Wet cutting outdoors
When outdoors, wet cutting with a continuous water feed on the blade integrated to machine is an effective method to reduce exposure to silica dust when using walk-behind saws.
An integrated water delivery system is used to direct a continuous stream of water onto the blade where it wets the material being cut and reduces the amount of dust generated. These saws have built-in water tanks, or water is supplied to the saw from a source such as a hose connected to a tap or portable tank.
Water flow rates must be sufficient to minimise the release of visible dust and be operated and maintained in accordance with the manufacturer’s instructions to minimise dust emissions.
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.
- Clean up any slurry produced during wet cutting before it dries and releases silica dust into the air. Wet slurry can be cleaned up using shovels or a vacuum.
Indoors or enclosed spaces
Wet cutting with a continuous water feed on the blade integrated to machine is an effective method to reduce exposure to silica dust when using walk-behind saws. Using wet methods indoors or in an enclosed area may not reliably keep exposure low so respiratory protective equipment (RPE) is required.
An integrated water delivery system is used to direct a continuous stream of water onto the blade which wets the material being cut and reduces the amount of dust generated. These saws have built-in water tanks, or water is supplied to the saw from a source such as a hose connected to a tap or portable tank.
Water flow rates must be sufficient to minimise the release of visible dust and be operated and maintained in accordance with the manufacturer’s instructions to minimise dust emissions.
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.
- Clean up any slurry produced during wet cutting before it dries and releases silica dust into the air. Wet slurry can be cleaned up using shovels or a vacuum equipped with a HEPA filter.
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 but is required when wet cutting indoors or in enclosed areas.
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 RPE not 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 (including the ones shown above), 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 person conducting a business or undertaking (PCBU) must provide health monitoring to a worker if their tasks require them to wear RPE 30 times or more in 12 months.
Further information