Short answer
Laboratory meth testing uses methanol-wetted gauze wipes over a 10 × 10 cm template, sealed and sent under chain of custody to an accredited laboratory. The result is a measured concentration in µg/100cm², which is the unit the Australian guideline uses.
Who this test is for
- Insurance claims, disputes and tribunal matters
- Confirming a positive field screen before anyone spends money
- Buyers and sellers who need a figure both sides will accept
How a NIOSH 9111 sample is taken
The Environmental Health Australia code of practice summarises the method: a 10 cm × 10 cm template is fixed to the surface, a gauze wipe pre-wetted with 3–4 mL of methanol is passed over it in three directions, folding between passes, and the wipe is sealed, labelled and logged. At least one blank (an unused wipe) travels with each property's samples to show the media was not contaminated.
Discrete or composite samples?
A discrete sample is one surface, one result, so you know exactly which room is affected. A composite combines several wipes into one analysis to keep costs down on a large property, at the price of not knowing which location contributed. The right mix depends on what the result has to prove.
Chain of custody and the laboratory certificate
Samples are kept cool where possible and sent with a chain-of-custody record so every handover is documented. The code of practice calls for analysis at a NATA- or IANZ-accredited laboratory. Queensland Health advises that post-clean-up samples go to an accredited laboratory able to certify the result.
Questions
How is a laboratory result different from a screen?
A screen indicates whether residue is above a threshold. A laboratory result measures how much is present, in µg/100cm², per sample.
How long do laboratory results take?
It depends on the laboratory’s turnaround at the time. The expected timing is confirmed when the test is booked.
Sources
- Australian Voluntary Code of Practice: Assessment, remediation and validation — former clandestine drug laboratories and other methamphetamine contaminated properties (2019) — Environmental Health Australia
- Illicit drug laboratories — Queensland Health
- Clandestine Drug Laboratory Remediation Guidelines (2011) — Australian Government — Attorney-General’s Department / Australian Crime Commission
Facts on this page checked against these sources on 29 October 2026.