Washington: Marijuana Potency Testing Accuracy Challenged


By Steve Elliott
Hemp News

The rules of Washington state's recreational marijuana legalization law, I-502, require a sample tested from every lot of marijuana. But how useful is that testing?

The program is having some success detecting substances like yeast, mold and bacteria, reports Evan Bush at The Seattle Times. About one out of every 10 batches of marijuana fails and can't be sold in recreational pot shops, according to Washington State Liquor Control Board data.

Potency testing, meanwhile -- which measures levels of tetrahydrocannabinol (THC), the primary psychoactive component, shows Washington weed is widely variable. Recreational marijuana averages about 16 percent THC in the state, but about 2.5 percent of samples test above 28 percent.

Laboratory directors from the state's 12 licensed pot-testing facilities said they are forming working groups to lobby the Liquor Control Board for more oversight of lab methods.

"Part of it is to invite more regulation," said Brad Douglass, scientific director at the Werc Shop, one of the 12 labs licensd by the state.

Randy Simmons, with the Liquor Control Board, claimed that the system is off to a good start. "The majority of what's out there on packages is correct," he said.

"The lab side is emerging," Simmons said. "As it matures, I think all those things that have been missed ... or things we find out we should be looking for, will all be changed."

A battery of state-required marijuana tests including potency and microbial measures cost $150 at the Werc Shop in Bellevue. Pot is ground, weighed and placed into a tube with solvent as the tube spins in centrifuge for potency testing.

Since Liquor Control Board rules don't direct growers on how to choose samples for testing, a grower can select the best-looking bud, rather than a more representative sample, giving an artificially high result. That's something Simmons hopes to change. Higher test results can mean higher wholesale prices for growers.

Some producers think others may be falsely boosting potency test results by adding THC-rich substances. That would explain some abnormally high results in the 30- to 40-percent range.

"I have suspicions some people are ... rolling it in kief and getting high scores," said Joby Sewell, whose AuricAG company grows marijuana in Sodo. Simmons agreed that the LCB is also concerned growers could dip their buds in hash oil before tests.

The agency is starting a secret-shopper program to find out; incognito marijuana-enforcement agents will buy products from pot stores and have them tested. If the results don't closely match the label, they'll investigate.

"Will we see people play games? Yes," said Simmons. "It happens in any industry out there. Will we catch them? Yes, we will."

Labs are also under scrutiny for allegedly fixing test results.

"There are some labs that have financial incentive to game the system for clients," said Miller of the Werc Shop. If producers don't like a lab's test results, they can take their business elsewhere.

Jessica Tonani, the CEO of Verda Bio, a Seattle cannabis biotech company, bought recreational marijuana from several 502 stores and had The Werc Shop blind-test them. Seven of eight purchases tested between 3 percent and 7.5 percent different from what their labels showed, according to Tonani’s numbers.

“In the medical world ... people that do tests sometimes do pay for higher test results,” said Simmons. “I want to make sure that’s not happening on the recreational side.”

It's not all about the THC, according to Dr. Jonathan Page, adjunct professor at the University of British Columbia and founder of a Canadian cannabis biotech company. Page sees high-THC cannabis as "the Everclear alcohol of the marijuana world."

According to Page, more than 100 minor cannabinoids, other than THC and CBD, play a role in marijuana's effects.

"What I'd like to see is that there's less of a focus on THC as sole molecule, and people saying, 'I have the most potent bud,' and more focus on the cannabinoid profile" and the overall experience, Page said.

That might mean more focus on the terpenes, the compounds which create the flavor and smell of cannabis, according to Page.

Photo: Lincoln 200 Blog