
It’s fairly well accepted now that meth testing is essential before buying or tenanting a property. These days there are many different companies to choose from and the costs vary considerably depending on the type of test and ability of the tester. Here we seek to clarify what the various tests are and what they are likely to cost.
Screening Tests
This is by far the most common test and certainly the most affordable. Here a technician will use a test to provide you with a basic yes/no type answer as to the presence of methamphetamine contamination in the property. A screening test that provides you with a level of contamination should be considered as a very tentative result pending a proper pre-decontamination test. Screening tests are not adequate if it is already known that contamination exists in a property. To commission one after contamination has already been identified is a waste of money.
In the right set of trained hands we recommend In-field Screening Tests whereby individual rooms/areas are sampled and a positive/negative type result is obtained for each individual area. These tests are sensitive to a specified cut-off level (usually 0.5 µg/100cm²) and would not alert you to levels below this cut-off in each area. That said, below that cut-off any contamination would be well below any commonly accepted harmful level. While the results obtained for these tests can be obtained instantly on the spot, it would be very poor scientific practice to set-up and complete them on the premises. Usually they would be properly labelled and taken where mistakes like cross-contamination are eliminated. Results are available on the same day as the test. Most of the time in-field screening tests cost around $300 for 5-8 samples, depending on the tester. We favour this testing method for screening tests. A major advantage is that the sampling does not damage paintwork whereby laboratory samples can sometimes leave tell-tale square patches on the surfaces.
Another very commonly used screening test is known as the Field Composite. This involves sending samples to a laboratory overnight for analysis but as a cost-saving measure fewer samples are processed so swabs are combined into one or two lab tubes for an average result. The result is a µg/sample number but it has to be taken with caution as it will not give you the exact location where the contamination was obtained and it does not offer a conclusive result for each area. That said it is far better than the old way that many testers still use, affectionately known as the ‘bum-wipe’ method. This involves using one single laboratory swab and using it 6-8 times throughout the property. Far too many testers have been trained to use this method. The resulting µg/sample is likely to cause panic as there is no indication whatsoever as to where the contamination was found. For example you might get a letter telling you that 4µg of methamphetamine was detected. That sounds awful but in-fact you won’t know if that is made up of 4µg from the garage alone or 0.5µg from each of the 8 areas tested. At Residue Testing NZ we have never agreed with this method and most technicians with a science background disagree with it. Field Composite testing would be charged by the number of lab samples, so anyone charging around $200 for a test is likely using just one lab sample. Testers charging upwards of $300 would hopefully be using more than one.
There is one more method that is becoming more widespread. Known as Laboratory Compositing it involves the use of multiple laboratory samples for a more acceptable sampling methodology. At the lab they take a small portion from each sample and add them together to give one result. Once again you will not know where the contamination is located but you will have better overall average results than the Field Composites above. The costs for this kind of test usually range above $300 depending on the number of areas sampled.
Pre-Decontamination Assessments
Once a property has been identified as having methamphetamine contamination the only correct course of action is a proper de-contamination assessment. There is no point in paying someone to do another screening test if you already know it is there, unfortunately we see this all too often.
A proper decontamination assessment will involve separate laboratory samples for all areas in the property. This may even involve more than one for large spaces. It is not uncommon for 8-15 individual samples to be sent to the laboratory. This test should focus on representative samples from each area rather than hunting down the areas that are likely to yield the highest result. While a screening test may involve taking swabs from the bathroom fan, a full assessment should rather focus on the bathroom wall to provide a more accurate idea of what the real contamination looks like.
If you consider that each laboratory sample is probably going to cost around $200, these assessments can add-up to quite a lot.
The Draft Standard for Testing and Decontamination of Methamphetamine currently being developed by Standards New Zealand also seeks to provide a minimum of relevant information along with the laboratory result. Photographs, property and sampling surface descriptions will help build a better picture to enable a decontamination professional to make the property safe. These requirements will likely push the costs up but are necessary.
Still Not Sure?
Most people will choose a screening test before purchasing a property or as a baseline before incoming tenants. This is fine provided you understand that it is screening. Anyone who does a screening test then provides you with a level should qualify that by saying that it is NOT the conclusive result for the property.
If there is already a screening test or evidence that methamphetamine contamination exists, it’s time to move to the next stage and commission a pre-decontamination assessment.
At Residue Testing NZ our trained technicians can discuss testing options with you. We aim to provide advice without causing panic.
Ph 0800 003636 to speak to a technician in your area.
www.methtest.co.nz