Can I Use Self-Test Kits? Yes, But…

Methamphetamine self-test kits can be a useful tool in the toolbox for homeowners and landlords who want an initial indication of whether methamphetamine may be present in a property.

But there is an important limitation: a self-test result should not be treated as confirmation that a property is meth-free.

The problem with self-test kits

The problem with self-test kits

Currently, we are not aware of any readily available self-test kits that have been validated for use in accordance with NZS 8510:2017 – Testing and decontamination of methamphetamine-contaminated properties.

Under the New Zealand Standard, testing used to confirm whether methamphetamine contamination is or isn't present needs to use an appropriate validated testing method.

This distinction is particularly important for rental properties. A negative result from a DIY self-test kit should not be relied upon as evidence that a property is clear of methamphetamine contamination, particularly if the result may later need to be produced as evidence in the Tenancy Tribunal.

Another concern is the information supplied with the kits.

MethTec has recently looked at two different self-test kits. Neither provided adequate manufacturer data explaining the kit's detection threshold or sensitivity.

That raises some obvious questions: At what level will the kit reliably detect methamphetamine? How sensitive is it at lower concentrations? What testing has been undertaken to validate its accuracy? What is the likelihood of a false negative?

Without this information, it can be difficult for a homeowner or landlord to understand exactly what a "negative" result actually means.

A recent example

A recent example

Last week, MethTec attended a property where the landlord had already carried out their own testing using a self-test kit purchased from Bunnings.

The landlord tested four areas of the house and reported that all four tests were negative.

MethTec subsequently professionally sampled the property and sent the samples to the laboratory for analysis.

The composite laboratory result was 20.2 µg/100 cm².

There are several possible explanations for the difference.

The landlord may simply have tested the wrong areas. The self-test kit may not have been sufficiently sensitive at the contamination levels present. There may have been an issue with the kit itself, or it could have been a combination of these factors.

We can't know from that case alone.

What it does demonstrate is the danger of assuming that a few negative DIY tests mean an entire property is negative.

Self-Test Kit

So, should you use a self-test kit?

So, should you use a self-test kit?

Yes – but understand what it can and can't tell you.

A self-test kit can be a useful preliminary screening tool. It may help identify an area that previously tested positive now tests negative or another that was previously positive is in fact still positive.

But don't treat a negative DIY test as confirmation that a property is clear.

Where a result needs to be relied upon for a tenancy matter, property transaction, insurance issue or other formal purpose, professional sampling using recognised methods and laboratory analysis provides a much stronger and defensible result.

Our advice: use self-test kits as a tool in the toolbox – not as your final confirmation.

MethTec – Professional Methamphetamine Testing & Reporting

methtec.nz | 0800 746 384