Recently construction workers were exposed to asbestos whilst carrying out renovation work on a multi-storey building. A worker was using an electrical jackhammer to remove old waste pipes from a penetration in a concrete floor slab. As the work progressed, the worker noticed that the consistency of the concrete material changed and appeared to become softer. Material on the underside of the slab was dislodged and fell approximately 5 metres onto the floor below, contaminating a large area with dust and debris. Other construction workers were in this area at the time of the incident.

After workers raised concerns, laboratory testing was conducted and it was confirmed that the material contained a mixture of plaster, white asbestos and synthetic mineral fibre. Only the worker using the jackhammer was wearing respiratory protection. The incident resulted in a number of workers being exposed to asbestos. The affected area required extensive remediation to remove the asbestos contamination.

Work area showing asbestos-containing debris and close up of asbestos-containing debris, by Department of Energy, Mines, Industry Regulation and Safety - WorkSafe division

Contributing factors

• The work was carried out in a multi-storey building built in the early 1970s, when asbestos was frequently used in construction materials.
• The asbestos-containing material was in an inaccessible location, as it had been covered by approximately 600mm of concrete.
• Consultants had previously carried out a hazardous materials audit on the building and produced a hazardous materials register. The register did not identify the presence of asbestos in this area of the building as it was a non-intrusive, presumptive survey report, and not suitable for any invasive activity.
• The hazardous materials register advised that caution should be exercised during any works that could disturb wall and slab penetrations.
• Hazardous materials surveys usually only contain information regarding the presence of visible materials in the building.
• The asbestos-containing material was not shown in the building’s construction drawings. There was no other information available to suggest asbestos would be present in this area of the building.
• No further investigations or exploratory testing were carried out prior to the renovation works.
• The Safe Work Method Statement did not address the presence of asbestos material, nor its safe removal.
• The workers were not informed that the area may contain asbestos.
• No dust control measures were implemented. Most of the exposed workers were not wearing any respiratory protective equipment, despite the presence of dust created by the jackhammering of the concrete floor. Even without the presence of asbestos, such dust is likely to contain respirable crystalline silica, which is hazardous.

Action required

1. Before construction or renovation work, conduct a risk assessment to determine the presence of asbestos and other hazardous materials.
2. Note that asbestos registers are generally based on non-intrusive inspections and only contain information on visible materials. Areas of the building that are inaccessible are likely to be out of the scope of the asbestos register.
3. Consider carrying out exploratory investigations and testing to determine the presence of asbestos before major works.
4. If there is any risk that asbestos may be present, implement adequate dust control measures and ensure workers wear adequate respiratory protection.
5. Ensure control measures are implemented to control general construction dust and ensure workers exposed to such dust wear adequate respiratory protection.
6. Ensure all workers are provided with adequate information, instruction and training regarding the tasks they are required to perform, including tasks which may involve exposure to hazardous substances or construction dusts.

Further information

Further information can be obtained from WorkSafe’s website or by contacting customer services on 1300 307 877 or email safety@demirs.wa.gov.au

This Alert contains safety information following inquires made by WorkSafe about an incident or unsafe practice. The information contained in this Alert does not necessarily include the outcome of WorkSafe’s action with respect to an incident.  WorkSafe does not warrant the information in this Alert is complete or up to date and does not accept any liability to any person for the information in this report or as to its use.