Health Canada has been flagging legal cannabis products containing incorrect amounts of THC content — up to five times more of the ingredient than advertised.

Since recreational legalization took effect in October 2018, the federal agency has ordered 15 recalls of products due to labelling errors in the actual levels of THC and CBD present.

In one instance, a package of pre-rolled cannabis cigarettes was determined to have five times the THC content posted.

Other instances had THC levels below that listed.

“The (federal) cannabis regulations require licence holders to investigate complaints received about the quality of cannabis and, if necessary, to take corrective measures,” Health Canada spokeswoman Tammy Jarbeau said in an email.

“In the cases where THC or CBD content was improperly labelled, federal licence holders have chosen to voluntarily recall their product.”

Most of those recalls were of dried flower, though some involved cannabis oil.

One recall from February 2019 said caps that were supposed to contain non-psychoactive CBD oil “may contain THC sativa caps.”

But the federal regulator said it’s generally satisfied with the industry performance.

“Generally, the cannabis industry has a high overall compliance rate with the Cannabis Act and its regulations, and any packaging or labelling errors related to THC or CBD content have been limited relative to overall industry sales,” Jarbeau said.

Even so, a spokesperson for Alberta-based licensed producer Aurora Cannabis said Health Canada has recently ordered changes to product labelling related to potency.

One Calgary chocolatier who’s preparing to market cannabis edibles said regulators have told him of THC level errors in such products.

It’s something Todd Pringle said he’s determined to avoid by incorporating his own testing system at his production facility in the city’s northeast, while other producers contract out that task.

“It’s something I never, ever want to see come up because it’ll turn people off edibles and be a black mark on the industry,” said Pringle, CEO of Wabi Sabi Brands.

He said the company first tests the potency of the cannabis oil it infuses into its chocolate, then screens its sweets twice more, using a $120,000 device.

The key to that is proper mixing, which can be a challenge to the viscosity of cannabis oil, said Pringle.

“Whether it’s THC or CBD, that stability is really hard to achieve,” he said.

Health Canada says its regulations generally allow for a 15 per cent variability in THC or CBD levels — either above or below the labelled amount.

But that can rise to 25 per cent for lower THC content products.

Canadian producers had the advantage of learning from U.S. counterparts that went before them in states such as Colorado, which embraced legalization in 2014, said Denver-based cannabis industry consultant Dan Rowland.

Dan Rowland of the City of Denver’s Office of Marijuana Policy and Department of Excise and Licenses smiles while chatting at City Hall in Calgary, Alta., on Monday, Feb. 6, 2017. Lyle Aspinall/Postmedia Network

“In the old days, you could shop around for a test until you got the result you needed,” said Rowland, who’s worked with Canadian producers and retailers.

“Our margins of error, of what was acceptable, was huge.”

That’s since evolved considerably in the U.S. and was never the case in Canada, which has been governed by more stringent national regulations, he said.

For one, Canada’s limit of 10 mg of THC for edible packages is far lower than those in the States.

Any recalls or production-labelling errors in Canada, said Rowland, “are par for the course for a relatively immature market.”

Maintaining proper THC and CBD levels in cannabis-infused products and beverages, he said, is proving a challenge.

“It’s why with the drinks you’re seeing lots of (marketing) delays,” said Rowland.

Jarbeau said it’s up to licensed producers to rectify quality complaints from the public but that “any followup actions to complaints will be consistent with Health Canada’s compliance and enforcement policies and procedures.”