This safety alert is a reminder to consider whether asbestos-containing materials (ACM) may be present before carrying out high-pressure water spraying or using compressed air. Disturbing ACM can release asbestos fibres and contaminate surrounding areas, posing risks to workers, occupants, and others nearby.
What happened?
WorkSafe has been notified of a number of instances in recent years where waterblasting was carried out on roofs which contained asbestos.
In the most recent case, the waterblasting work was carried out on a residential property built in the 1970s that had decramastic roof tiles.
Following the work, debris was identified across the property and inside the home. Testing later confirmed the roof tiles contained chrysotile asbestos and that asbestos-containing material had contaminated both indoor and outdoor areas.
Specialist assessment determined that remediation was required to address the contamination.
What was learned?
This incident highlights the importance of identifying whether asbestos-containing materials may be present before work begins, particularly when working on older buildings.
Decramastic roofing installed before asbestos was phased out may contain asbestos. Before undertaking work that could disturb roofing materials, asbestos risks should be identified and assessed.
![[image] Tile chips](https://www.worksafe.govt.nz/assets/About-us/News-and-media/image-tile-chips.jpg)
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Where asbestos-containing materials are known or suspected to be present, appropriate controls should be implemented before work starts. Controls should be selected based on the nature of the work and the risk of disturbing asbestos-containing material.
High-pressure water spraying (including water blasting) must not be used on asbestos or ACM. Likewise, compressed air must not be used on asbestos. Both are specifically prohibited under the Asbestos Regulations.
Thorough planning and assessment before work begins can help prevent asbestos exposure and reduce the risk of contamination to surrounding areas.
Actions to consider
- ACMs may be present before carrying out work on buildings built before the 2000s.
- Identify and assess asbestos risks before undertaking waterblasting or other work that could disturb roofing materials.
- Ensure appropriate controls are implemented where asbestos-containing materials are known or suspected to be present.
