Plastics May Degrade Cannabis Potency in Food

In June, a statement of claim for a $500-million class-action lawsuit sent shockwaves across North America’s legal cannabis markets. Filed in Calgary, Alberta, the lawsuit alleges that seven of Canada’s largest licensed cannabis producers (known as LPs) sold numerous cannabis-oil products whose active cannabinoid (THC and CBD) content was “drastically different” than the amounts listed on product packaging. Some products contained as little as 54% of the THC or 51% of the CBD they were listed to contain, while others contained as much as 118.5% of the listed THC.

The suit’s statement of claim argues that many of the cannabis oils in question were sold to consumers in containers such as plastic bottles or those with caps that may have rapidly absorbed or degraded the THC or CBD content within them.

The class-action suit has not yet been certified by a judge, but industry discussion that followed news of its filing was concerned less with the potential lawsuit and far more with the possibility that the plaintiff may be broadly correct in finding that cannabis oil products lose cannabinoids to plastic packaging. If that’s true, it’s bad news for producers of consumer cannabis oils (which occupy a tiny market share), but it’s far worse news for Canada’s burgeoning cannabis beverage market—and the legal market for cannabis and cannabis beverages that many analysts expect will open federally across the United States within the next few years.

Cans and Chemistry

Worries about changes to cannabinoid potency have been active since before the class-action suit. Canada’s largest LP, Canopy Growth, has long signalled its intention to focus on cannabis beverages. Last fall, ahead of Canada’s second phase of legalization (allowing cannabis foods, beverages, extracts, and topical products), the company held a lavish pre-launch for its slate of 16 infused beverages and edibles, due to go on sale in mid-December 2019. After the drinks didn’t appear before Christmas, Canopy stunned the industry in January 2020 by pushing back its beverage-portfolio launch. Despite being backed by a $4 billion investment from U.S. beverage conglomerate Constellation Brands, Canopy ran up against the same problem raised in the class-action suit: The cannabinoid potency in their beverages wouldn’t remain stable.

“There is an interplay with the cans and the chemistry in the drink itself,” Canopy Growth CEO David Klein told Yahoo Finance.

Lagunitas Brewing Company, in Petaluma, Calif., determined that a similar problem with potency loss in its Hi-Fi Hops cannabis beers was connected to plastic can liners. Others say the problem is the products themselves. Either way, cannabis products housed inside plastic-lined cans, plastic bottles, and plastic jars tend sometimes to lose the potency of their cannabinoids—the active ingredients in cannabis products.

Though there are more than 60 cannabinoids that exist in the cannabis plant, the two that appear in the highest doses at present are THC (responsible for the “high” associated with cannabis) and CBD (a non-intoxicating compound with various medical effects). Like all cannabinoids, THC and CBD appear as waxy compounds.

“Cannabinoids aren’t water soluble, and the beverages they’re trying to put them into are basically water,” says chemist Mark Scialdone, PhD, chief science officer for Connecticut’s BR Brands, which offers a portfolio of cannabis products. “That’s why the drinks are losing potency to the side of the can: For cannabinoids, it’s a low-energy pathway. Given the opportunity, cannabinoids would rather stick to the liner of the can than to be in the drink the person’s consuming.”

Dr. Scialdone says that cannabis drinks require cannabinoid oils to be suspended in an emulsion soluble in beverages—but such emulsions are in their very early days. For Dr. Scialdone, the best emulsion to compare these beverages with is milk, which contains fat emulsified by milk’s naturally occurring glycolipids, which prevent the fat from separating out. By comparison, existing cannabinoid emulsions are nowhere near as stable as milk, largely because cannabinoids such as THC and CBD are very hydrophobic.