There is a steady increase in the use of methamphetamine (otherwise called ‘P’ or meth) throughout most sectors of society and the NZ Ministry of Health Drug Use Statistics suggest that ±3% of the NZ population use methamphetamine on a regular basis. This is approximately 140,000 people.

Methamphetamine is relatively easy to manufacture but because illegal manufacture seriously contaminates a dwelling and leaves obvious traces, most methamphetamine is manufactured away from city residential properties in more remote locations and rural properties although the simple 'shake and baker' method is limited to an AGee Jar and is easy to conceal.


Nevertheless, methamphetamine is still manufactured in local neighbourhoods and from time to time we come across properties where there is serious contamination either from heavy use or from an amateur laboratory. In such cases properties may need extensive decontamination by a trained team. 

The commonest situation we find is contamination from individual use and minor traces are relatively easy to remedy by steam cleaning of carpets and thorough washing of walls and interior surfaces.


The New Zealand Standard suggests that levels below 1.55µ (1.5 parts per million) can be managed with thorough cleaning. Our screening tests are very accurate and can detect levels that exceed this limit with an on-the-spot test. Between 0.05µ to 1.5µ would require the employment of professional cleaners but above the 1.5µ level we would recommend secondary and extensive testing of each room in the property including crawl spaces and roof spaces. Samples collected during secondary testing are sent to an independent laboratory to give an accurate indication of levels and recommendations for remediation.

This is not very common, but owners need to be aware that if not detected and managed, most literature suggests that residues from heavy use or manufacture can be harmful to the health of people living in the residence—especially young children.


For landlords we suggest a screening test of a property between tenants. Methamphetamine contamination is more commonly found in rental properties so testing between tenants would be sensible. Another tip would be to include in the rental agreement the requirement for a methamphetamine test before release of the rental bond so that tenants are aware this matter is taken seriously.  If this puts them off signing an agreement, maybe a problem has been averted!  Also with the provisions of the Residential Tenancy Act shifting the blame to landlords for renting properties that are contaminated, then it becomes especially important to assure that rentals are free from contamination. Tenants now have the ability to sue for damages if affected by meth contamination that has not been disclosed by a landlord.

For property buyers we also recommend an initial screening to give comfort and knowledge that the property is not at risk. We have found methamphetamine contamination in very high-end properties so the appearance and value of the property is no real indicator of the presence or absence of contamination. Banks and Insurance Companies are regularly asking for an independent screening test (usually as part of the property inspection report) and usually Insurers are putting a maximum payout amount on decontamination repairs.  Buyers should check with their Insurer and make sure they know the extent of cover available.

We do stress that owners don’t rush into unnecessary expense and commission full-scale testing unless there is good reason to suspect contamination. A screening test will give reassurance in most cases and the results of this initial test are an empirical guide regarding what to do next. As methamphetamine use is common and residential methamphetamine labs are rare, a screening test should be sufficient for most purposes and we can advise the extent of decontamination required.


It is increasingly important for potential buyers to assure themselves that no trace of methamphetamine usage is in a property they own or plan to buy. Landlords are especially vulnerable as tenants are more likely to manufacture or use Methamphetamine and either will leave indelible traces.

"There's a big difference between living in a house where someone smoked methamphetamine, and living in a house that was used to manufacture the drug." National Poisons Centre toxicologist Dr Leo Schep says.  "People living in a laboratory environment risk suffering adverse cardiovascular, respiratory and dermal effects following the exposure to organic solvents, acids, alkalis and other chemicals. However, people dwelling in a house where previous tenants had smoked methamphetamine and there is some evidence of low concentrations on surfaces, have minimal risks of toxicity."

"The risks would be similar for people who live in a house that had previous dwellers who smoked cigarettes or marijuana. They will have exposure to these drugs but the concentrations will not be sufficiently high enough to cause either psychoactive or toxic effects to people who may have had inadvertent, and brief, dermal contact with these surfaces."


However, properties that have been the location of a methamphetamine lab or housed heavy users may have significant contamination and subsequent dwellers will probably report skin irritation, eye conditions and respiratory discomfort.


Tests showing low levels of contamination do not mean owners will have to undertake extensive repairs or involve commercial cleaners. Quorum will give screening information regarding levels that are manageable with little more than a rigorous wash down of surfaces with soap and water plus carpet cleaning.  However, if our tests show contamination well above the 1.5 µ level then we can advise appropriate action. Most houses we test come below this level so a good cleaning may reduce any short or long-term risk. 

Research shows that frequently people are unaware of the causes of their general feelings of malaise and we hear the term 'a sick house'. Often respiratory discomfort is thought to be cause by dampness, mould or other factors. Methamphetamine traces are often the last things people expect.


On a practical level housing contaminated with methamphetamine will be worth less and may require extensive decontamination. Even after such decontamination there may still be doubts in the mind of a future buyer about the possible long-term effects of methamphetamine use.

Quorum Health takes a health focused approach to the use of methamphetamine and its staff are experienced professionals who can candidly discuss the health risks associated with contamination. Reassurance and peace of mind are not far away.


For further information and advice contact us at:


Quorum Health and Scientific

027 220 1424 or email

(c) QHL 2018

Quorum Health and Scientific 
Technical and business solutions for you
Just a phone call away .... 027 220 1424

0800 652 123

© QHL 2015

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