Short answer
Queensland has not legislated its own figure. Testers, insurers and agencies such as the RTA work to the Australian Government’s 2011 Clandestine Drug Laboratory Remediation Guidelines, which say methylamphetamine on inside surfaces should not exceed 0.5 µg/100cm². The Environmental Health Australia code uses 10 µg/100cm² for commercial areas and roof spaces.
Where the 0.5 figure comes from
The Clandestine Drug Laboratory Remediation Guidelines were published by the Commonwealth in 2011, prepared by the Attorney-General’s Department and the Australian Crime Commission. Section 5.2.4 states that for methylamphetamine on inside surfaces, “its concentration should not exceed 0.5 µg/100cm²”.
In 2019 Environmental Health Australia published a voluntary code of practice that sits alongside the guidelines. It keeps 0.5 µg/100cm² as the residential investigation level and remediation criterion for indoor surfaces, and sets 10 µg/100cm² for commercial and industrial settings and for roof spaces.
Queensland has not legislated a number of its own. The Residential Tenancies Authority points landlords and tenants to the national guidelines, and Queensland Health points to the enHealth guidance on clandestine drug laboratories.
Reading the unit
| Term | Meaning |
|---|---|
| µg | microgram — one millionth of a gram |
| 100cm² | a 10 cm × 10 cm square of surface, marked with a template |
| 0.5 µg/100cm² | half a microgram of methylamphetamine on that square |
A laboratory result is reported per sample in µg/100cm². A field screen does not give a number; it shows whether residue is above the kit’s threshold. The code of practice notes that 0.5 µg is the maximum reporting level for presumptive screening kits, provided the sample is taken over 100cm².
Which rooms have to be sampled?
The 2011 guidelines say any room or area used by a child under 16 should be sampled at least once. In practice a residential test also covers living areas, the kitchen and bathroom exhaust points, return-air vents and any room where use is suspected.
Smoking versus manufacture
A property used to make the drug is usually far more contaminated than one where it was smoked, with residue through ceilings, ducts and plumbing and sometimes in the yard. Both can exceed 0.5 µg/100cm². The guidelines expect a former manufacturing site to be investigated by a suitably qualified expert with environmental science, environmental health or occupational hygiene experience.
What happens when a result is over 0.5?
A result over the residential figure means the affected surfaces need attention before the property is treated as fit to live in. For rentals, the RTA says the owner carries those costs and must keep the property fit to live in. After works, a clearance test re-samples the property; Queensland Health advises that post-clean-up samples go to an accredited laboratory that can certify the result.
Questions
Is there a legal meth limit in Queensland?
There is no Queensland-specific legislated figure. The national 2011 guidelines set 0.5 µg/100cm² for inside residential surfaces, and Queensland bodies such as the RTA refer to those guidelines.
What does 0.5 µg/100cm² actually mean?
Half a microgram of methylamphetamine on a 10 cm × 10 cm patch of surface. A microgram is one millionth of a gram.
Does the same figure apply to a commercial building?
No. The Environmental Health Australia code of practice uses 10 µg/100cm² for commercial and industrial settings and for roof spaces.
Sources
- Clandestine Drug Laboratory Remediation Guidelines (2011) — Australian Government — Attorney-General’s Department / Australian Crime Commission
- Australian Voluntary Code of Practice: Assessment, remediation and validation — former clandestine drug laboratories and other methamphetamine contaminated properties (2019) — Environmental Health Australia
- Drug contamination in a rental property — Residential Tenancies Authority (Queensland)
- Illicit drug laboratories — Queensland Health
Facts on this page checked against these sources on 29 October 2026.