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Use of high-pressure water spray equipment on asbestos roofs

In August 2021, as part of cleaning, sealing & painting at a house residence, a home maintenance business used high pressure water spray equipment on an asbestos cement roof. Asbestos contaminated dust and debris (ACD) was spread across the yard, in vegetation, on adjoining structures, as well as the driveway and a car. ACD also spread on to a neighbour’s driveway and car, and onto the street and into council drains.

In a separate incident also in August, a painting contractor appears to have used high pressure water spray equipment on a roof believed to have asbestos containing material ACM debris was distributed on parts of the property and two neighbouring houses.

Safety issues

Queensland laws prohibit the use of certain tools and work methods when working with asbestos-containing materials (ACM) as they can generate dangerous airborne asbestos fibres. It is illegal to use high pressure water spray equipment on asbestos, including asbestos cement roofs, fences and walls. High pressure water spray equipment destroys the binding matrix of ACM, leaving cement debris and asbestos in the air. This results in widespread contamination putting people’s health at risk.

A person conducting a business or undertaking (PCBU) has a duty to ensure workers and others are not exposed to the risk of airborne asbestos. The person with management or control of the workplace (PMCW) must also take all reasonable steps to ensure that any ACM has been identified at the workplace. If the PMCW cannot identify ACM, but a competent person reasonably believes materials may contain asbestos, then the PMCW must assume asbestos is present.

Ways to manage health and safety

Taking steps to manage risks is a condition of doing business in Queensland. Effective risk management starts with a commitment to health and safety from those who manage the business. If an incident occurs, you'll need to show the regulator that you’ve used an effective risk management process. This responsibility is covered by your primary duty of care in the Work Health and Safety Act 2011.

Use the hierarchy of controls to help decide how to eliminate and reduce risks in your place of work. The hierarchy of controls ranks types of control methods from the highest level of protection and reliability to the lowest. It’s a step-by-step approach to eliminating or reducing risks. You must work through the hierarchy of controls when managing risks, with the aim of eliminating the hazard, which is the most effective control.

Possible control measures to prevent similar incidents

You should never use high-pressure water spray equipment to prepare for painting, coating or sealing of asbestos cement roofs as there is no system of use that can effectively capture or suppress asbestos fibres in such circumstances. A PCBU must not use, direct, or allow a worker to use high pressure spray on asbestos or ACM. Before carrying out maintenance of a roof, consider whether asbestos could be present. When working on buildings constructed before 1990, it is likely asbestos could be present in roofing and other sheet materials.

Identifying asbestos or ACM is the first step in managing the risk of exposure to asbestos. As there may be more than one person in the workplace responsible for this duty, it is important that all duty holders consult, cooperate and coordinate with each other as well as consulting with workers and health and safety representatives. There may be a person within the business who is competent to identify asbestos. If there is not, an external competent person should be engaged.

There are a number of ways to control the risks associated with asbestos or ACM in the workplace. PCBU’s must always aim to eliminate the hazard and associated risk first, for example by removing the asbestos sheeting. The removal of asbestos cement roof sheeting must be performed in accordance with the Work Health and Safety Regulation 2011.

If it is not reasonably practicable to remove the asbestos, then other control measures must be implemented to ensure people are not exposed to airborne asbestos. This may involve a single control measure or a combination of different controls that provide the highest level of protection. These can include but are not limited to the following examples:

  • Enclosing the asbestos - creating a structure built around the asbestos so that it is completely covered to prevent exposure of the asbestos to air and other substances. Enclosure should only be used on non-friable asbestos where removal is not reasonably practical and where the asbestos is at risk of damage from work activities.
  • Encapsulating - the asbestos that is encapsulated in a resilient matrix (e.g. in reinforced plastics, vinyls, resins, mastics, bitumen, flexible plasters and cements) has little opportunity to release airborne asbestos unless the matrix is damaged. This type of encapsulation will seal any loose fibres into place and should be used only when the original asbestos bond is still intact.
  • Sealing - Sealing is the process of covering the surface of the material with a protective coating over the asbestos to prevent exposure to airborne asbestos. Sealing asbestos is the least effective method for controlling the release of airborne asbestos. It should only be considered as an interim control while a more effective control such as removing or enclosing can be implemented.

Workers will need to use personal protective equipment (PPE) in combination with other effective control measures when working with asbestos. Your selection and use of PPE should be based on your risk assessment. PPE includes but not limited to disposable coveralls, gloves, boot covers, respirators and protective eyewear.

Administrative controls can be used to minimise any remaining risks (e.g. safe work practices), so far as is reasonably practicable and can include work methods or procedures that are designed to minimise exposure to asbestos fibres as well as the information, training and instruction needed to ensure workers can work safely.

Administrative control measures and PPE do not control the hazard at the source. They rely on human behaviour and supervision and used on their own tend to be the least effective in minimising risks. You must not use administrative controls exclusively to minimise the risk of falls unless it is not reasonably practicable to use a higher order control.

The control measures you put in place should be monitored and reviewed regularly to make sure they work as planned.

More information

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