How an asbestos sample is taken and analysed
The analysis is the easy half. The risky half is the bit where somebody breaks a piece off your wall, and that is the half worth paying for.
('Everything on this site that ends in “get it tested” ends here. It is worth knowing what that actually involves, because the two halves of it have very different risk profiles.
Why sampling is the part with the risk
A sample means deliberately removing a small piece of a material you suspect contains asbestos. Done badly — dry, with a power tool, indoors, without containing the debris — it is the exact disturbance the rest of this subject is about preventing. That is why sampling is normally treated as work for a licensed asbestos assessor or an occupational hygienist rather than for the owner.
It is also why we are not going to publish a step-by-step method for doing it yourself. There is a version of this page on other sites that reads like a recipe, and we think that is a mistake: the people most likely to follow it are the people least equipped to deal with it going wrong.
What a competent sampler does
Without turning it into instructions, a properly taken sample involves: settling first whether the material should be sampled at all; wetting it so nothing becomes airborne; taking a small piece from a representative spot with the least disturbance; sealing the sample in a labelled, double-contained bag; sealing the spot it came from so the material is not left open; and cleaning up in a way that does not spread anything. Friable material is not sampled this way at all — it is a licensed job from the outset.
What the laboratory does
The sample goes to a laboratory accredited by NATA for asbestos identification. Analysis is typically by polarised light microscopy with dispersion staining, which identifies the fibre type present. Turnaround is usually short.
The report will tell you the sample reference, the result — a named fibre type such as chrysotile, amosite or crocidolite, or no asbestos detected — and the method used.
Reading the result properly
Two traps are worth naming. The first: a result covers the sample, not the building. One negative does not clear a house that contains products from four different decades. The second: a positive result is not an emergency in itself. It tells you what the material is; what to do about it depends on condition and on whether it is going to be disturbed.
If the question you actually have is “what is in this property”, the right document is a survey covering the whole building, room by room, with condition and recommendations. That is what buyers and renovators need, and it is a different product from a single-sample result.
Keep the paperwork
Reports, surveys and clearance certificates are worth filing properly. They matter when you sell, when a tradesperson asks what is in the walls, and when the next owner wants to know why the bathroom lining was left in place. Asbestos documentation is one of the few pieces of house paperwork that genuinely appreciates in usefulness.
', 0)Frequently asked questions
Why will you not explain how to take a sample myself?
Because sampling is the step with the exposure risk, and a written recipe is most likely to be followed by whoever is least equipped to handle it going wrong. Sampling is normally work for a licensed asbestos assessor or occupational hygienist.
What does the laboratory actually do?
A NATA-accredited laboratory analyses the sample, typically by polarised light microscopy with dispersion staining, and reports the fibre type identified — chrysotile, amosite or crocidolite — or that no asbestos was detected.
Is a positive result an emergency?
Not in itself. It tells you what the material is. What to do about it depends on its condition and on whether anything is going to disturb it — intact, undisturbed bonded material is often best left alone.
Should I get a single sample or a survey?
A sample answers 'what is this sheet'. A survey answers 'what is in this property', room by room with condition and recommendations, which is what buyers and renovators generally need.
Sources
What this page explains is based on these official sources. If you check one and it does not match what you read here, send it to us and the article gets corrected.
- National Association of Testing Authorities. Accredited laboratories — the accreditation body whose analysis identifies asbestos
- NSW Government. Asbestos in NSW — the NSW Government asbestos portal