Buying a home these days is fraught. First you have to find one you can afford (tricky in Auckland's market), and then - more often than you might think - ensure it is not contaminated by methamphetamine.
New Zealand has one of the highest rates of meth usage in the world (a 2015 world survey found us fourth just behind El Salvador, Philippines and Australia).
Meth (also referred to as P) can be made out of readily available household products plus one more ingredient, ephedrine.
This is often trafficked into New Zealand from China and South-East Asia, or extracted from cold medicines.
Local 'cooks' can whip up a batch in a few hours and they may just have used the kitchen in that nice house you're thinking of buying.
These 'cooks' have limited knowledge of the chemical processes involved, are often high themselves and will move their operations from house to house regularly to avoid detection. Safety is the last thing on their minds.
That's bad news for home buyers; and not just for health reasons. The prevalence of meth contamination has prompted insurance companies to raise their rates.
IAG, which owns the brands NZI, AMI and State Insurance, last year increased the current standard excess from $400 to $2500 for meth claims.
On top of the excess increase, rental home owners will also face an increase in their annual premiums of between $40 and $130.
Property investors are taking no chances with a 2016 survey revealing that around three-quarters of them will ask for a methamphetamine test on properties they are looking to buy. A baseline test for meth can run to hundreds of dollars (see sidebar).
This has led to a boom in companies offering testing and decontamination services.
Yet experts in the field are suggesting the industry's meth paranoia is misplaced.
Dr Leo Schep, a toxicologist at the National Poisons Centre, at the University of Otago, is one.
He believes that when addressing problems associated with contaminated houses, there are two separate issues - "a house where someone smoked methamphetamine, or a house that was used to manufacture methamphetamine".
In a post on the science media website, he says that "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 living 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 standards were reviewed last October by the Ministry of Health (MOH).
That resulted in a recommendation to increase the level of meth needed to warrant a clean-up by up to four times the previous guidelines. But that hasn't solved the issue.
To date the Standards New Zealand (now MBIE) process has not resulted in an outcome - one is expected later this month - but the presence of guidelines endorsed by MOH mean that players in the property market must pay attention to them.
Dr Nick Kim, a senior lecturer at Massey's School of Public Health, is another who believes we have, in many instances, been over-playing the dangers of meth contamination.
"Ordinary home buyers have become vulnerable because the simple presence or absence of meth can have an impact on the ability to sell a house."
He believes the guidelines are causing an unnecessary panic in the industry.
"Exceeding a guideline is not the same as saying that there is a genuine health risk.
"Guidelines include many safety factors. Both the older and newer guideline values correspond to regions where there is no measurable health risk.
"At a toxicological level they are effectively indistinguishable from each other, because both are hundreds of times lower than the point where we would expect to be able to measure the lowest pharmacological effect."
However, it's these MOH guidelines that impact on banks and other legal entities.
"Yes, when an MOH guideline exists, councils, insurers, mortgage lenders, landlords etc need to show compliance to be able to 'prove' the absence of a health risk for legal purposes."
In December last year, part of Whakatane Hospital's paediatric ward was closed after a new report of someone using P in a toilet a year previously.
It was tested and cleared, but situations like this in State houses, workplaces and rental properties throughout the country bring disruption and uncertainty to tenants, workers and home buyers.
Last month, it was discovered that almost 400 Housing New Zealand properties were deemed uninhabitable because of methamphetamine contamination.
Kim has witnessed a case where a property sale fell through when no meth at all was detected, simply because the real estate agent and buyer did not know how to properly interpret the laboratory report.
Signs of contamination
Signs of manufacturing are more detectable than
a user-only situation.
A clan (clandestine) lab could be detected by overpowering chemical smells, signs of damage/aggression (e.g. holes in walls or damage to doors) and chemical staining in basins.
There may be makeshift fume exhaust ducting systems, dead grass (where waste chemicals have been discarded) waste containers, opened lithium batteries and paint thinners.
Top 5 meth hotspots
• Hamilton Central
SOURCE: University of Auckland
The Geography of Methamphetamine Manufacture in New Zealand.
He agrees with Schep in making the distinction between a house where meth has been smoked and one used to actually manufacture the drug.
"The lab scenario is high risk, because a range of chemicals used to manufacture the meth have contaminated the indoor environment.
"Solvent vapours in particular are higher risk because they can be inhaled. The MOH guideline document was written only with this scenario in mind.
"Residues left from the smoking scenario are low risk, because these involve traces only of methamphetamine itself deposited on surfaces, and inhalation is not a significant exposure route.
"In broad terms, I would expect that indoor residues left on surfaces from smoking meth are at a similar type of risk level to residues left on surfaces from tobacco smoke."
So are home buyers wasting their money ensuring a home is 'clean of meth' before moving in?
"I wouldn't dictate what tenants or home buyers should do - this has to be left up to the individual choice," says Kim.
"I personally wouldn't bother with getting any testing of this type done unless (a) there was strong evidence that the property was used to manufacture meth or other drugs or (b) I was planning to rent the property rather than live in it, or (c) I was planning to re-sell it within a couple of years."
Kim believes that if the purpose of testing was to carry out a genuine indoor health risk assessment, the testing companies should be looking for and reporting on other more common problems such as presence of lead paint, and asbestos.
"For children, lead poisoning still represents a genuine health risk, and is unfortunately still too common."
How long do the harmful effects of meth last once it is in the atmosphere or absorbed into gib board?
"Meth residues are persistent but not eternal," says Kim.
"Since meth is an organic compound, it does gradually break down over time, and some is lost by evaporation.
"From the controlled studies I have reviewed - once deposited on a surface, a lot of the original meth is then lost again by evaporation in the first few days, at levels that would be of no health concern.
This leaves a lower level but more persistent 'tail' of residues and these can last for months and years in some cases."
Indeed Kim, in a 2016 paper, compares the traces of meth found on banknotes to those found in houses where the drug has been smoked.
"Internationally, detection of drug residues including methamphetamine on banknotes has not been interpreted as a direct cause for public health alarm, and there is no prospect of any jurisdiction requiring that banknotes be decontaminated between users.
"In a hierarchy of relative health hazards and risks, contaminated banknotes and houses where methamphetamine has been smoked would be at the low end of any scale."
Anthony Morley, managing director at Enviro Clean & Restoration (NZ's only qualified methamphetamine clean-up company), says there has been a downturn in inquiries about contamination since the new guidelines were released.
"This threw a lot of doubt and confusion into whether a house required decontamination or not. Was it a user-only situation or was the property used as a clandestine manufacturing lab?" he says.
"The standard should tidy up a lot of this uncertainty and people will then be guided by an actual standard instead of a guideline only."
Enviro does not do testing as it considers it a conflict of interest with its decontamination efforts.
Currently, any forensic detection over 0.50 micrograms is determined as requiring decontamination to reduce meth levels to less than 0.50 micrograms.
This will likely change when the new standard is set - it's looking like the New Zealand Standard will be set at 1.5 micrograms, like some American states.
On average, a decontamination of a typical three-bedroom home with low-level contamination may take three days to complete.
Retesting is generally performed 72 hours later. This test can range between $160-$250. A stage two in-depth test can cost $1600-$2800.
Decontamination costs depend on the level of contamination, size of property, level of difficulty and materials involved.
SOURCE: Anthony Morley, managing director, Enviro
Advice for owners
"It is important that purchasers carry out their own, thorough due diligence on a property before they purchase," says REINZ CEO Bindi Norwell.
"If they are concerned that a property may have been exposed to meth, they should obtain a test from an independent, reputable testing company.
"The cost of a test is small compared to the investment required to buy a house."
What are the agents' roles and responsibilities in informing prospective buyers?
"Licensed real estate agents are bound to follow the disclosure requirements set out in the Real Estate Agents Act Professional Conduct and Client Care Rules 2012.
"Meth contamination is considered an underlying property defect and needs to be disclosed to prospective buyers.
"If a vendor refuses to allow the contamination to be disclosed, the agent is required to walk away from the listing."
What are the REINZ policies regarding this?
"REINZ is part of the National Standards Committee that has, over the past 18 months, been developing the New Zealand Methamphetamine Testing and Decontamination Standard (P8150).
"The standard is due for release in late June.
In addition to the national standard, REINZ will be releasing best practice guides to help REINZ members understand the standard and ensure that they are meeting their obligations under the Professional Conduct Rules.
"Real estate agencies also have internal policies for dealing with potential or known meth contamination.
What recourse do buyers have if they find their houses have contamination - and they weren't informed by the agent?
"The facts of every situation will differ considerably. A purchaser will need to obtain legal advice to assess what, if any, action they can take.
"Licensed real estate agents are required to meet a number of legislative requirements and to follow the disclosure requirements set out in the Real Estate Agents Act Professional Conduct and Client Care Rules."