Asbestos

Asbestos is the name used for a group of natural minerals that are made up of many small fibres. These fibres are very strong and are highly resistant to heat, fire, chemicals, and wear due to friction.

In the past, the properties of asbestos made it popular for things, such as:

• asbestos-cement cladding and roofing,
• backing material for floor tiles and vinyl sheets,
• insulation for thermal protection (eg, around fireplace lagging for insulation around pipes, heaters and hot water cylinders),
• textured ceilings and sprayed-on wall surfaces.

Asbestos was mainly imported and used before the 1980s. Once the health risks of asbestos were known, its use was gradually stopped and other materials used instead. However, products and appliances with asbestos content may still be around, particularly in homes built before 1984.

The most common types of asbestos fibre you are likely to find are:

• chrysotile (white),
• amosite (brown) and
• crocidolite (blue).

Asbestos is a risk to health only when it is inhaled (breathed in) as fine dust. The risk to health increases with the number of fibres inhaled and with frequency of exposure.

When asbestos dust is inhaled, larger fibres tend to be cleared by protective mechanisms in the lungs and upper respiratory tract. The finer fibres are more difficult to remove, and may become deposited deep in the lungs, or penetrate further into the body. It is these fibres which can cause a number of diseases including cancers, such as mesothelioma, lung cancer, non-malignant lung asbestosis, pleural plaques and pleural thickening.

Small quantities of asbestos fibres are common in air, arising from natural sources (weathering of asbestos-containing materials), and windblown soil from hazardous waste sites, deterioration of automobile clutches and brakes, or breakdown of asbestos-containing materials.

The highest risk of exposure to asbestos in the home is through home renovation, by cutting or drilling through asbestos-cement sheeting or sanding down asbestos-containing lino or tiles.

Generally, asbestos-containing materials that are in good condition will not release asbestos fibres. There is no danger unless fibres are released and inhaled into the lungs. The risk from exposure to asbestos in the non-occupational setting is considered to be low since the concentrations of asbestos fibres are low.

Exposure levels indoors depend on asbestos type and its condition. Constant exposure to crumbly or powdery (friable), damaged, exposed, or poorly maintained asbestos materials may increase the health risk.

Testing a sample in an approved laboratory is the only way to find out if a material contains asbestos. Any samples you deliver or take to the health protection officer should be in a sealed envelope or in a zip-lock bag. All care must be taken to prevent creating any dust. Wash all utensils under running water immediately after use. If any material drops on the carpet or floor, DO NOT VACUUM or SWEEP, clean up all debris with a damp cloth and dispose of after use.

Cement Sheet
Find an area that has been damaged or a discreet corner of the material. Dampen the material with water to prevent dust and break off a portion the size of a $2 coin, or scrape off enough material to fill a teaspoon.

Textured Plaster Ceilings/Walls
Find an area that has been damaged or take from a discreet area, such as under a light shade, smoke alarm, or in the corner of the room. Dampen the area with water to prevent dust. Scrape a teaspoon full of the textured material off the ceiling, ensuring the 'pimply' or textured part of the plaster is included. NOTE: Plaster or Gib panelling underneath the textured material is not needed.

Vinyl Floor Coverings or Linoleum Tiles
Dampen an area, using scissors or a craft knife, cut off a piece about the size of a $2 coin. Ensure that vinyl floor covering samples include the papery backing material which usually remains stuck to the floor as this is where the asbestos is found.

Dust Sample - Swab
Use a facial tissue (NOT a wet wipe).Dampen the facial tissue and then gently wipe over dust surface, folding in the dust and continuing to wipe over the surface area you want to test. Place the used wipe or tissue inside a plastic bag and seal.

If there is asbestos or Asbestos Containing Material (ACM), confirmed by laboratory analysis in your home, you should talk with a health protection officer about:

• leaving it as it is, disturbing it as little as possible
• sealing, encapsulating or enclosing it
• removing it.

External cladding should not cause any concern if not damaged. Even if the cladding is deteriorating, the Ministry of Health advises that the cladding should be sealed rather than removed or replaced. The process of removal will disturb the asbestos, where if left in place, the amount of fibres released is not considered to be a health risk. However, if you have asbestos-containing roofing, be aware that the ceiling space under the roof may have high concentrations of asbestos dust, particularly if the roofing is weathered and brittle.

Do not use powered tools or high-pressure water blasting on external cladding as this will release large amounts of fibres, which are a health risk when they dry.

The Ministry of Health strongly advises that you use Worksafe NZ certified contractors to remove ACMs as exposure to asbestos fibres is a danger to health.  These contractors understand the risks and are equipped to handle and manage disposal of asbestos and ACMs.

If you still intend to do the work yourself make sure you follow the advice in the Ministry of Health booklet Removing Asbestos From the Home available from Toi Te Ora Public Health. You can also read the Worksafe NZ Approved Code of Practice for the Management and Removal of Asbestos.

• Asbestos exposure has been associated with serious lung disease.
• See your doctor if you think you have been exposed to asbestos.
• Smoking increases the risk of some asbestos related diseases.  If you stop smoking it will help to protect your health.