How samples are collected
Asbestos testing starts with physical sampling by a qualified asbestos surveyor. The surveyor takes a small piece of the suspect material, typically about 2 to 3 centimetres across. They'll use a sharp tool to cut or scrape the sample, wetting the material first to prevent fibres becoming airborne during collection.
The surveyor wears appropriate personal protective equipment (PPE) including a P2 respirator and disposable gloves. Each sample is placed in a sealed, labelled bag, and the sample location is recorded on a floor plan or written log. If the sampling creates any damage to the material, the surveyor will seal the area with tape or a small patch to prevent fibre release.
You cannot safely collect samples yourself. Disturbing suspect materials without training and equipment creates a genuine inhalation risk. Leave sampling to a qualified surveyor.
What happens at the laboratory
Samples are sent to an accredited laboratory for analysis. In Australia, look for NATA accreditation. In New Zealand, labs should hold IANZ accreditation.
The primary method used is polarised light microscopy (PLM), sometimes called dispersion staining. A lab analyst prepares the sample on a glass slide and examines it under a specialised microscope. The way asbestos fibres interact with polarised light and specific refractive index liquids allows the analyst to identify whether asbestos is present and determine the fibre type.
For samples where PLM results are inconclusive, or where very low concentrations of asbestos are suspected, the lab may use additional techniques. These can include point counting to estimate asbestos content as a percentage, or in some cases, transmission electron microscopy (TEM) for higher magnification analysis.
How long results take
Standard turnaround for most commercial labs is three to five business days from when the sample arrives. Many labs offer an express service with results in 24 hours or same-day, for an additional fee. If you're working to a tight project timeline, discuss turnaround options with your surveyor when booking the survey.
Understanding your results
Lab results will report one of three outcomes for each sample:
- No asbestos detected (NAD): The sample does not contain asbestos fibres. The material can be treated as non-asbestos for management purposes.
- Asbestos detected: The report will specify the type of asbestos found. The three main types are chrysotile (white asbestos), amosite (brown asbestos), and crocidolite (blue asbestos). Some materials contain more than one type.
- Inconclusive: Rare, but it happens. The lab may recommend re-sampling or a different analytical technique.
The type of asbestos matters because it affects how the material must be managed. All types are hazardous, but friable materials and those containing amphibole asbestos (amosite and crocidolite) are generally considered higher risk and are subject to stricter removal requirements.
What to do with the results
If asbestos is detected, the results feed into your asbestos register and any associated management plan. Your surveyor or asbestos consultant will typically provide a risk assessment and recommendations alongside the lab results. These recommendations might range from "label and monitor" for stable materials in low-traffic areas, through to "remove before any works proceed" for damaged or friable materials.
If you're testing because you're planning renovation or demolition work, a positive result means you'll need a licensed asbestos removalist to deal with the material before your builders can start.
Keep your lab certificates on file. They're part of your compliance records and may be requested during regulatory inspections or when selling the property.
A note on DIY testing kits
You may see mail-in asbestos testing kits marketed online. While the lab analysis itself may be sound, collecting the sample without training creates a real health risk and may breach workplace safety regulations. A qualified asbestos surveyor provides the full picture: safe sampling, proper documentation, and professional interpretation of results.