High-pressure cleaners on asbestos roofs

In March 2022, a unlicenced painter in Sherwood used high-pressure water spray equipment to clean a corrugated asbestos cement sheet roof for painting. As a result, asbestos contaminated dust or debris (ACD) was spread across the site and neighbouring properties, including internal parts of the house next door through open windows.

In May 2022, a unlicenced painter in Tarragindi used a high-pressure cleaner on a corrugated asbestos cement sheet roof before painting. As a result, ACD was spread across the site, footpath and neighbouring properties. The spread of ACD could have been greater if the painter had not been asked to stop by a contractor working at a neighbouring property as he recognised the roof potentially contained asbestos.

In June 2022, a unlicenced painter in Coorparoo used high pressure equipment on another corrugated asbestos cement sheet roof in preparation for painting. This again resulted in ACD spread across several locations on the property, a neighbouring yard, motor vehicles, the footpath and kerb and channel.

Investigations into these incidents continue.

IMPORTANT

These findings are not yet confirmed, and investigations are continuing into the exact cause.

Safety issues

Asbestos is most dangerous when it’s deteriorating, damaged or disturbed. Cleaning asbestos cement roofs, fences and walls with high-pressure water spray equipment can destroy the binding matrix of asbestos containing material (ACM), resulting in cement debris and airborne asbestos fibres and widespread contamination.

Disturbed asbestos fibres that resettle on surfaces stick to everything including walls, plants, garden soil and lawns and are very easily disturbed again. These fibres remain for years if not decades, if the contamination is not remediated.

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 containing materials as there is no system of use that can effectively capture or suppress asbestos fibres in such circumstances. It is illegal to use high pressure water spray equipment on asbestos, including asbestos cement roofs, soffits, fences and walls.

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 building elements.

Identifying asbestos or ACM is the first step in managing the risk of exposure to asbestos. This must be done by someone with the proper training, qualification and experience. As there may be more than one person in the workplace responsible, it is important all duty holders consult, cooperate and coordinate with each other as well as consulting with workers and health and safety representatives.

If asbestos has been found, the next step is to perform a risk assessment. This will help to figure out:

if there is a risk your workers could be exposed to airborne asbestos
whether any effective control measures are in place
what actions you can take to control this risk
how urgently you should act.

After assessing the risk of exposure to airborne asbestos in your workplace, you’ll need to implement control measures. You may need to use a combination of these controls in order to meet your responsibilities under WHS laws.

PCBUs must always aim to eliminate the hazard and associated risk first, for example by removing the asbestos sheeting. If the asbestos or ACM in your place of work is posing a serious risk, you should remove it. The How to safely remove asbestos code of practice 2021 (PDF, 2.22 MB) sets out how to remove asbestos including requirements for inspections, removal, transport and disposal.

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:

Enclosing the asbestos
(creating a structure built around the asbestos so 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
Asbestos that is encapsulated in a resilient matrix (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. If encapsulation is recommended, the person carrying out the work should:
- be trained and experienced in working with asbestos
- isolate the area
- use suitable RPE that complies with AS/NZS 1716: Respiratory protective devices
- wear suitable protective clothing such as disposable overalls
- follow a safe system of work that reduces the risk of creating airborne asbestos
- follow a decontamination procedure upon completion of the task.
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. The process either coats the material, reducing fibre release, or binds the fibres together. Asbestos should be sealed, coated or painted to protect it. There are alternatives specifically designed for Super Six roofs, including surface primers, fungicides and paints. Sealing asbestos is the least effective method for controlling the release of airborne asbestos.

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 (disposable coveralls with fitted hoods and cuffs should be worn and need to be of a suitable standard to prevent penetration of asbestos fibres - disposable coveralls rated type 5, category 3 (EN ISO 13982–1) or equivalent would meet this standard)
footwear boot covers and gloves (laceless boots such as gumboots are preferred where practicable and if boot covers are worn, they should be of a type that has anti-slip soles to reduce the risk of slipping)
gloves, which should be determined by a risk assessment (if significant amounts of asbestos fibres may be present, disposable gloves should be worn)
respiratory protective equipment (RPE). The selection of suitable RPE depends on the nature of the asbestos work, the probable maximum concentrations of asbestos fibres that would be encountered in this work and any personal characteristics of the wearer that may affect the facial fit of the respirator (e.g. facial hair and glasses). A competent person should determine the most efficient respirator for the task.

Administrative controls can be used to minimise any remaining risks (e.g. safe work practices) and can include work methods or procedures designed to minimise exposure to asbestos fibres as well as the information, training and instruction needed to ensure workers can work safely. Workers who are required to conduct asbestos-related activities and wear PPE must be given adequate training and supervision to enable them to fit and use the equipment correctly and conduct the task in a safe manner.

Tag your equipment to warn others not to use water blasters on asbestos containing material. (See figure 1)

Prohibited use of water blasters

Figure 1: Prohibited use of water blasters tag poster

Source: Asbestos website

Administrative controls and PPE are the least effective at minimising risk because they do not control the hazard at the source and rely on human behaviour and supervision. These control measures should only be used:

to supplement higher level control measures
as a short term interim measure until a more effective way of controlling the risk can be used, or
when there are no other practical control measures available.

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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