Sealing, painting, coating and cleaning of asbestos cement products
As a first priority removing asbestos-containing material (ACM) must be considered. Where ACM cannot be removed and must be sealed, painted, coated or cleaned, there may be a risk to health. Such tasks can only be carried out on ACMs that are in good condition. For this reason, the ACM needs to be thoroughly inspected before the work begins.
There is a risk to health if the surface of asbestos cement sheeting has been disturbed (eg from hail storms and cyclones) or if the sheeting has deteriorated as a result of environmental factors, such as pollution. If asbestos cement sheeting is so weathered that its surface is cracked or broken the asbestos cement matrix may be eroded, increasing the likelihood that asbestos fibres could be released if disturbed.
If treatment of asbestos cement sheeting is considered essential, a method that does not disturb the matrix of the asbestos cement sheeting needs to be used. An airless sprayer at low pressure is preferred to rollers or brushes on exposed (or unsealed) asbestos as rollers and brushes may cause abrasion/damage and result in fibres being released from the surface of the material. Under no circumstances can ACM be water-blasted or dry-sanded in preparation for painting, coating or sealing.
In addition to any equipment required to complete the particular task (eg paint, paint brushes, paint rollers or airless spray gun/equipment) the following equipment may be required on site before the work begins:
- disposable cleaning rags
- bucket of water and/or a misting spray bottle
- spare PPE
- suitable asbestos waste container
- warning signs and/or barrier tape.
Personal protective equipment (PPE)
- See guidance on selection and use of protective clothing
- It is likely that a class P1 or P2 half-face respirator will be adequate for this task, provided the recommended safe work procedure is followed. For further guidance on selecting appropriate respirators see Appendix H of the Managing asbestos in workplaces Compliance Code.
- Where paint is to be applied, appropriate respiratory protection to control the paint vapours/mist must also be considered.
Preparing the asbestos work area
- If work is to be carried out at height appropriate precautions must be taken to prevent the risk of falls.
- Before starting assess the asbestos cement for damage.
- Ensure appropriately marked asbestos waste disposal bags are available.
- Carry out the work with as few people present as possible.
- Segregate the asbestos work area to ensure unauthorised personnel are restricted from entry (eg close doors and/or use warning signs and/or barrier tape at all entry points). The distance for segregation needs to be determined by a risk assessment. If working at height segregate the area below
- If possible, use plastic sheeting secured with duct tape to cover any floor surface within the asbestos work area which could become contaminated.
- Ensure there is adequate lighting.
- If using a bucket of water do not re-soak used rags in the bucket as this will contaminate the water. Instead either fold the rag so a clean surface is exposed or dispose of as asbestos waste and use another rag.
- Never use high-pressure water cleaning methods.
- Never prepare surfaces using dry-sanding methods. Where sanding is required consideration needs to be given to removing the ACM and replacing it with non-ACM.
- Wet sanding methods may be used to prepare the material provided precautions are taken to ensure all the runoff is captured and filtered where possible.
- Wipe dusty surfaces with a damp cloth.
Painting and sealing
- When using a spray brush never use a high-pressure spray to apply the paint.
- When using a roller use it lightly to avoid abrasion or other damage.
Decontaminating the asbestos work area and equipment
- Use damp rags to clean the equipment.
- Where required, use damp rags and/or an asbestos vacuum cleaner to clean the asbestos work area.
- Place debris, used rags, plastic sheeting and other waste in labelled asbestos waste bags/containers.
- Wet-wipe the external surfaces of the asbestos waste bags/containers to remove any adhering dust before they are removed from the asbestos work area.
- Carry out the following personal decontamination procedure in a designated area:
- If disposable coveralls are worn for the activity, clean the coveralls and respirator while still wearing them. Coveralls can be cleaned using a HEPA vacuum, damp rag or fine-water spray and the respirator can be cleaned with a wet rag or cloth.
- While still wearing the respirator remove coveralls, turning them inside-out to entrap any remaining contamination and then place them into a labelled asbestos waste bag.
- Remove the respirator. If a non-disposable respirator was used inspect it to ensure it is free from contamination, clean it with a wet rag and store in a clean container.
- Disposable respirators do not require cleaning. They need to be placed into a labelled asbestos waste bag or waste container dedicated for asbestos waste.
- Visually inspect the asbestos work area to make sure it has been properly cleaned.
- Consider seeking a competent independent person’s visual assessment to confirm there is no visible asbestos residue.
- Clearance air sampling is not normally required for this task.
- Dispose of all waste as asbestos waste.