NIST’s Cannabis Testing Program Enters Second Phase, Seeks New Labs

A federal agency is looking to partner up with commercial and forensic cannabis labs to check the accuracy and reliability of their testing standards.

The labs will receive marijuana and hemp samples directly from the National Institute of Standards and Technology (NIST) as soon as April. Using their own standard methods, the facilities will then be asked to measure the levels of cannabinoids and heavy metals in the samples and report their findings back to NIST. The results should help determine which testing methods are unreliable, and which labs should change their practices.

These tests mark the second phase of NIST’s cannabis program, which has already found discrepancies in lab standards within the US.

Going into phase two

NIST launched the first phase of its testing program, the Cannabis Quality Assurance program (CannaQAP), last July.

“We’ve been hearing throughout the industry [that if] you send a sample to three or four labs or more, you might get different values from all of them,” Brent Wilson, a research chemist at NIST and member of its CannaQAP, told Analytical Cannabis at the time.

“So, the goal is to improve the analytical measurements that are being done in cannabis laboratories and forensic laboratories, to where we’re promoting good manufacturing practices and encouraging safe products,” he added.

During the CannaQAP’s first phase, Wilson and his colleagues sent samples of hemp oil to over 100 commercial and forensic labs. These oils contained specific concentrations of THC, CBD, and other cannabinoids, which the labs had to identify and quantify.

“We ended up with 116 participants, which was more than what we planned for,” Wilson tells Analytical Cannabis. “And we ended up getting probably 85 percent of the participants submitting data, which is a lot more than what you typically see in a laboratory study. That speaks to the level of interest in the community.”

While the results from this first phase are still under wraps – a report is due to be published in February – Wilson and his team have already spoken to the labs that fell short of the correct measurements.

“We’ve already released the preliminary data to the participants, so[…] they can start to make implementations if there’s something wrong with their method, [as] their values were lower than the NIST values,” Wilson explains.

And the sooner these affected labs make their improvements, the better, because the second phase of NIST’s program won’t be any easier. This time the labs will be testing solid plant material.

“The [cannabis] oil is a very homogeneous material,” Wilson explains. “But when you receive a plant material – let’s say you get a five-gram bag – it’ll have stems, it’ll have buds, it’ll have leaves possibly in there. That material is very heterogeneous.”

The complexity of the new samples could mean more labs fail to get the right results. So, to better understand how such tests go awry, Wilson and his team are hoping to partner up with even more labs this time around.

“We already have a lot of labs starting to sign up to participate,” he says. “But we are planning for more than what we had the first time to try and ensure that we have plenty of materials for these laboratories.”

Any lab interested in participating in the study has until February 5 to enroll. All data provided will be anonymized.

What are the new tests?

So, once signed up and in receipt of a NIST cannabis sample, what are labs expected to look for? Well, it depends on which sample they receive, says Wilson.

“There is going to be one primary set of samples that people can sign up for two different studies: one is for cannabinoids and moisture, and the other one is toxic elements,” he tells Analytical Cannabis. “These samples are all hemp materials.”

According to Wilson, the toxic elements that labs should look for include 13 different heavy metals. While this figure is much higher than the “big four” heavy metal quota currently prioritized by most cannabis labs (lead, cadmium, mercury, arsenic), the CannaQAP team argue that it’s more in keeping with tobacco regulations.

“The FDA has included [approximately] 11 elements for their tobacco products. And they’re considered harmful contaminants,” Wilson says. “So we opened up the scope of what we were looking at[…] because tobacco and cannabis are similar – they’re different plants but they’re grown on similar farmlands, so you’re going to see a lot of the same elements.”

But partnered labs won’t just be receiving legal hemp material. Samples of marijuana will also be parceled out for testing – just not heavy metal testing.

“The additional new thing[…] is our second set of samples,” Wilson says. “These are marijuana samples that are going to be above 0.3 percent THC concentration.”

“But these materials are only for the cannabinoids and moisture study,” he adds. “For toxic metals, it doesn’t really matter if it’s cannabis. High THC or low THC, the metal measurements aren’t going to change.”

To access these federally illegal samples, a lab must first have a Drug Enforcement Administration (DEA) registration license. Fortunately, the NIST team are on hand to help with relevant administrative work.

“We’ll do our due diligence,” says Wilson, “to check and make sure that the DEA registration numbers do match what’s on file, to make sure that we’re not sending illegal samples to just anybody.”

A higher standard

In the short term, the CannaQAP team want their program to help those cannabis labs that haven’t quite got their techniques right just yet. But in the long term, the team have far greater ambitions. The ultimate aim, says Wilson, is to produce a set of cannabis reference materials that the whole cannabis industry (and all forensic labs) can rely on.

“NIST [does] not currently have a reference material available,” he tells Analytical Cannabis. “We’re working on that for a hemp plant material that will probably be [available] early 2022. But in lieu of that, we’re giving [labs] more than enough material […] to help carry them over until that reference material would be available.”

“We’re thinking years out in advance,” he adds. “This time next year, maybe we incorporate an oil sample back in, or we incorporate some type of edible or an extract. All that ties into our plan of building a reference material profile, to provide testing laboratories and forensic laboratories the necessary tools they need.”

Given the desperate need for hemp and marijuana reference materials in the North American cannabis sector, it’s not surprising that NIST isn’t the only organization trying to provide them.

The independent lab standards organization AOAC International also launched its own cannabis testing standards program in 2019. Since then, the Cannabis Analytical Science Program (CASP) has outlined its own analytical method for detecting THC in hemp plants on a dry weight basis.