When it comes to meth testing, how are you to know where to start? There are countless testing companies, products and procedures which claim to show you where meth is in your property and how much is present. Then the next question is, what will these companies and test results ACTUALLY show me?

One thing for certain is that the sensitivities (and therefore the results) of meth testing kits will vary dramatically. Before you go with a testing kit or testing company, make sure you know exactly what you’re getting from it and what kind of testing will be done.

It might seem obvious, but the more areas you sample, the more you are likely to find meth. So if you want to increase the likelihood of identifying potential problems, you will test as many surfaces as you can. Meth residues are far greater in areas where meth activity has occurred. If you don’t test an area that has been subjected to meth, then you won’t find meth. If you only get 3 or 4 areas tested, they you won’t find the potential meth risks in your property.

So after your property is meth tested, and you receive the report -  what do those results even mean? The result will depend on the kits and testing methodology used to take the samples.


Indicative meth testing

Indicative testing or more inaccurately referred to as “Composite” testing can use one swab or wipe over several areas often eight areas to give you one result. So one area is swabbed using a 10x10cm template in one location and what does the tester know?

Unfortunately, not a lot as the swab is yet to be analysed by an independent IANZ accredited laboratory.  But this swab is going to be used another seven times? Yes. This swab now running out of methanol (the alcohol used to exchange the contamination from the tested surface to the swab) is used on another 10x10cm area of another surface using the same template. So the questions are: was the template contaminated from the previous test? Is this new area contaminated at all? Or has the tester now contaminated this area from contamination from the previous test?

So, at the end of eight locations tested with a single swab, could only one of the areas be contaminated? Well using this method no-one will ever know. But we now have a result and it has come back over the MoH meth standard threshold of 1.5µg/100cm, so what does this mean?

Well you could divide the result by eight as their were eight areas tested, but this would assume that the contamination is the same in each sample location. The test becomes less effective when several areas are tested using the same swab. This test only indicates there is contamination present but the reported result is not very reliable.

So what is a “Lab Composite”?

This is where a separate swab, a separate 10x10CM template, and a change of gloves are used for each location or surface. This reduces the chance of cross contamination, but only gives you one result. Part of each swab is cut off and inserted into a separate tube (maximum of five) and analysed as one sample. This then has the same issues applied as the previous test where the assumption is that each room or surface has an equal level of contamination.



Detailed single swabs of separate rooms and materials are the most reliable forms of tests available. This will provide a picture of what is really happening not just indicating. You will be able to see the level of contamination in a particular area, and this cannot be cross contaminated by any other area - like you may find in some other testing procedures.

Whichever meth test and report you intend to get, Chemcare will be able to help find the best possible solution for your meth decontamination needs and budget. Even if you need guidance finding a reliable testing company - we can help there too.