By John Brunstein
5 Apr 2016
What’s tested for in Cannabis product QC testing, and what’s important to look for in a testing lab?
Good question! The first part of the answer will differ a bit depending on your jurisdiction, while the second part is generally applicable. Let’s deal with the first part first, namely, what’s tested for?
Under the Canadian MMPR system, Cannabis produced by a Licensed Producer must at a minimum be tested for the following things:
Acceptance limits (which can be as stringent as ‘not detected’) are set by Health Canada for each of these categories, generally based on their accepted limits for Natural Health products. All lots of Cannabis product from a Licensed Producer must have a record demonstrating the lot was tested by a suitable lab (the second part of your question, more on that below) and met these criteria before it can be sold. A product lot which fails any one Quality Control (QC) criteria on this list can’t be sold, or even given away; it has to be destroyed, with appropriate record trail of the destruction. Since this is a significant loss of product for a Licensed Producer (LP) if this happens, LPs strive through their processes to ensure that each and every lot will be suitable to pass QC testing.
This attention to detail needed to ensure product lot quality, and the act of having suitable analytical testing done, are expensive for the producer both in terms of effort and direct financial costs. This cost is justifiable however as it is essential for protecting the health of the end consumers, as exposure to fungi, yeast, aflatoxins, bacteria, and heavy metals can cause serious health issues particularly with prolonged usage.
In different legal jurisdictions for either medical or recreational Cannabis products (such as Colorado, Washington state, California), similar rules are in place. While the exact list of what’s tested for, and what limits are imposed, vary a bit between jurisdictions, the overall requirements are similar. That’s because across a wide range of regulatory bodies, these rules and limits are believed to be important in protecting the end user.
Now consider the various ‘grey market’ Cannabis producers which exist in some jurisdictions (notably, Vancouver). These are the producers marketing products through various quasi-legal, poorly regulated “dispensaries” which operate outside of the LP licensing system, and have publically admitted that product supplies are coming from unlicensed, unregulated sources. Notice above where we considered that quality control is essential for the health of the end user, and that suitable production and testing cost time and effort? Like any other business, Cannabis cultivation is competitive; it’s not hard to guess where an unlicensed producer can increase their profit margin by cutting back (or altogether cutting out) QC practices and QC testing. The result is very much one of caveat emptor or buyer beware – that dispensary Cannabis you bought may very well be poisoning you.
This isn’t an idea which hasn’t occurred to some end users, and so there’s starting to be an interest in various third-party Cannabis testing labs. Advertisements for services are showing up, and end users are understandably interested. If your product wasn’t stringently tested under regulatory oversight, why not have that testing done yourself, to assure you the product you’re getting is safe?
This brings us back to the second part of the question – what’s important in a testing lab. Well, first off, they need test equipment. Different kinds of equipment (HPLC, GC, GC-MS, ICP-MS, bacteriology equipment) are needed to provide the full range of tests required, as different analytes (things being tested for) need different devices. As well as the equipment, you need trained operators who know how to use the equipment.
Figure 1: HPLC is the standard for many different types of QC testing.
These two parts are the easiest for a testing lab to fulfill. Used lab testing equipment is regularly available, often at a fraction of original pricing. For a few thousand dollars, pretty much anyone can outfit their garage with possibly-working surplus equipment. Finding a chemistry undergrad who’s used some or all of these techniques once or twice in their degree, and who is looking for a job, isn’t that challenging either. You’re all set, right?
WRONG! No, there’s not necessarily anything wrong with the used equipment, or the chemistry undergrad – what’s wrong with this picture is that the equipment and protocols haven’t been properly calibrated, maintained, and process validated. In other words, there’s no assurances that the equipment works, or that it works accurately, or that the process used in testing the samples on this equipment gives accurate results. An accredited analytical laboratory – the only sort you want to trust your health to – will have had to put a lot of time and effort (and expense) into getting all of the instruments properly serviced and calibrated, with records of all this. They’ll have had to obtain traceable (that is, proven) test materials of known concentrations and shown upper and lower limits of detection for each analyte and method, as well as created standard curves (signal response curves, used for interpolating results of unknowns). These sorts of instrument and process validation aren’t only done when the service is first set up, they also have to be repeated at regular (perhaps monthly, or a few times a year) intervals – with appropriate record keeping. The lab will also have to create Standard Operating Procedures (SOPs) for each test, so that the operator knows exactly how to perform each test in such a way that the result is believable. If all of this sounds painful and expensive, you’re right! In fact this is why most LPs don’t operate their own analytical testing units; it’s so expensive, and such a lot of trouble, that it’s really only worthwhile for a few specialized companies to do this right and be able to show certification (such as from ISO or other accrediting body) that their results are valid. LPs (or other interested parties, such as end users) then send samples to these accredited analytical labs, which in effect can spread the cost of all the background lab setup over many users.
Many people however either don`t understand this, or are intentionally misleading. Just like there are grey-market unlicensed producers with no incentive to meet essential QC standards for long term consumer health in using their products, so too there are self-proclaimed `testing services` who offer low cost, direct to consumer Cannabis product testing. If their price seems to be too good to be true, what are they doing to allow them to provide testing so much more cheaply than the legitimate accredited labs? Not being privy to what’s going on inside each specific case, the reader’s guess is as good as any – but it’s almost certainly done by cutting corners somewhere in the test and process validation, meaning the test results aren’t worth the paper they print on, and believing the results from a non-accredited lab is putting your health at risk.
The summary answer to the second part of the question then – what to look for in a testing lab, if you want to have your own testing done – is evidence for accreditation and assay validation. Here’s a good hint, at least in the Canadian market: a lab accredited for testing Cannabis, will have to have a valid, current narcotics license – and they’ll be willing to share a copy of this with you to prove they’re licensed. No narcotics license? Not a legitimate lab. Not in Canada, or looking for other evidence which might suggest the lab actually can provide valid data? Evidence of ISO accreditation is good (note however, ISO accreditation is pretty easy to fake or fraudulently attain, as ISO doesn’t actually maintain a record of all ISO accredited establishments. It ‘licenses’ subcontractors to perform accreditation and issue certificates in its name, and some of these subcontractors are less than scrupulous). Even better, ask direct questions: “What is the assay limit of detection? How often are calibration standards run? Can I see the results of the last standard calibration? Can I see the most recent instrument service records?” A legitimate lab will understand your reasons for asking these questions and be happy to provide detailed answers. After all, they spent the time and effort to have that validation and servicing done, you’re giving them an opportunity to get value out of having done it! Conversely, a less than legitimate lab will be defensive or come up with excuses why they are unwilling unable to share such information.
Finally, what about testing for other things not on our above list? For Cannabis, this can mean testing for various limonenes, terpenes, and similar compounds which impact taste and / or scent of product. All of the above holds true with regard to what’s required if you want really accurate testing for any of these – that is, a properly validated method on calibrated equipment, from a lab able to prove validation and calibration. However, if the required QC markers have all been done by appropriate methods, what about having these other markers tested by a lab which might be taking a few shortcuts? The health issues of the product have been controlled for, so in that case, there’s less possible for harm if a test result isn’t fully accurate. End users looking to buy these kinds of add-on tests can then weigh how much accuracy is worth to them. If it’s important, then you want evidence of assay validation, calibration, and the likes. If it’s not, then you don’t need such evidence but take the results with a grain of salt. In that case though, paying for the assay may be wasted money and your nose may be as good or better test instrument – and it’s free.