Cannabis-infused food products usually look just like any other foodstuff. In many cases, an infused product may taste quite similar to its non-infused counterpart. Yet on a food safety level, the two stand distinctly apart. Though cannabis flower contains a number of potentially active compounds, such as flavonoids and aromatic terpenes, the term “cannabis” in cannabis-infused product refers primarily to the addition of active cannabinoids—chiefly, tetrahydrocannabinol and/or cannabidiol, but also cannabigerol and cannabinol. Such cannabinoids are usually received from cannabis extractors in the form of cannabinoid distillate. Due to the heat and chemical extremes required to extract cannabinoids to distillate, this is good news for those worried about the potential for microbial pathogens endemic to the cannabis plant to contaminate products downstream.
Zamir Punja, PhD, a professor of plant biotechnology at Simon Fraser University in Burnaby, B.C., Canada, was lead author of a 2019 study that cataloged pathogens and molds affecting the cannabis plant. He notes that most of the seven or so pathogens affecting cannabis flower buds would not survive any solvent extraction, or liquid carbon dioxide, or temperatures higher than 60oC—the conditions under which cannabinoids are usually extracted.
“I would consider these methods to have eliminated living microbes,” Dr. Punja tells Food Quality & Safety. “What we don’t yet know is what would happen if a contaminated bud has [fungal] growth on it and the microbe produces a toxin. Some of these toxins can survive solvent extraction and are heat stable. So, they may survive through the extraction process, and possibly be concentrated. The majority of the mold should be killed by extraction, but it remains to be seen whether toxins that may be produced by the microbes growing on moldy product can still be detected in extracts.”
Kevin McKernan, the chief science officer and founder of Beverly, Mass.-based cannabis biotechnology firm Medicinal Genomics, concurs, noting that CO2 or ethanol extraction processes sterilize the cannabis flower, but may also enrich mycotoxins and pesticides in the process. “Not all microbial contaminants are flower derived, and regulators are still looking to ensure the infused products have not been contaminated downstream of the extraction process,” he says.
What kind of a threat do such processed mycotoxins pose for consumers? Charles T. Deibel, president of food safety testing firm Deibel Laboratories, acknowledges Dr. Punja’s and McKernan’s concerns, but he’s not certain how much we should worry about them. “Aspergillus produces an extremely heat-stable toxin aflatoxin,” Deibel says. “[Aflatoxin] is an extremely stable toxin structure, and it can absolutely survive some of the processing to make distillate, but it’s rare. You’re just looking at a numbers game. Bacteria are a hell of a lot more prevalent in recalls and [incidences of] foodborne [illness] than some of these oddball toxins like aflatoxin.”
Not just bacteria, says Lori Glauser, co-founder and interim CEO of Nevada cannabis testing firm EVIO Labs. Before infused foods and beverages go to market, producers are also testing for a variety of pathogens. “We test the final product, not just the cannabis ingredient,” Glauser says. “When testing for yeast, mold, E. coli, Salmonella, and mycotoxins in infused products, it is more likely that the pathogen is introduced from the food product itself rather than the cannabis component.”
Even the best company with all the right programs [will] still find a pathogen maybe once every five years—10 years if they’re lucky. But they find it. The pathogen is always waiting at your door.—Charles T. Deibel
It’s the food product, not the cannabis, that makes infused products so complicated, because, while infused foods come in an increasingly wide variety of shapes, flavors, and permutations, infused products are not subject to FDA oversight. “As soon as you put THC in a food product, the FDA says, ‘Not my jurisdiction,’” says Deibel.
When it comes to infused food products, FDA treats them more like medicine than like food, says Glauser. “The FDA requires that manufacturers have ‘reasonable assurance that food is not adulterated,’ and will perform sampling of certain commodities.” But the safety of THC-infused foods is overseen at the state level alone, and the differences in requirements from state to state vary widely.
“In California, each batch of cannabis is tested for E. coli, Salmonella, Aspergillus, and mycotoxins, says Glauser. “In Oregon, there is no requirement for microbial testing yet, but that is expected to change in 2021. In other states, product is tested for yeast and mold. In Massachusetts, product is tested for all of the above, plus coliforms and certain bacteria.”
But even between states that test for the same pathogens, differences may arise, says McKernan, who stresses that the sample size requirements, targets, and thresholds for failure differ from state to state.
All that testing is less demanding than that required of food products under FDA, adds Deibel, who says that food producers subject to FDA oversight must test many more batches of higher weights than are ever demanded of edible cannabis products.
Risk On the Rise
While the chances of getting Salmonella from a cannabis-infused gummy are fairly low, says Deibel, that relative safety is only for the time being. Producers may begin shifting norms and ingredients that have made previous gummies shelf stable. Meanwhile, with so many hoping to strike gold selling cannabis-infused foods and beverages, the variety of food types is expanding dramatically beyond gummies, cookies, and brownies.
The problem with savvy consumers looking for high-end quality and flavors is that they want nothing to do with the mass-produced ingredients that have proven themselves safe for consumers in large numbers. They want new and inventive flavors, and they often want them in chocolate products.
“Chocolate, and especially some of the toppings—fresh fruit, nuts—those can absolutely have Salmonella in them,” Deibel says. “If I were to name my five biggest concerns for Salmonella, they’d be chocolate, nuts, raw meat, raw ag [agricultural produce], and spices. Well, you’ve got raw ag in the form of fruit, and nuts, and spices, and those are all going on top of chocolate. Really fancy chocolates with curry spices or whatever, they are getting out onto the market, but they are not going through the same rigor of testing that the food industry would have subjected them to.”
He concludes that many food safety insiders are waiting for the first big Salmonella or Listeria or recall in the cannabis market. “It’s going to happen,” he adds. “It’s just a matter of time.”
To avoid becoming the company that suffers that recall, Deibel advises producers of infused foods to adhere to good manufacturing practices (GMPs) supplemented with aggressive sanitation programs, extensive training, and routinely validated equipment.
McKernan goes back even farther: He suggests food producers source ingredients from cannabis cultivators offering “good genetics,” such as the cannabis cultivars that exhibit pathogen resistance. “In [the] absence of fungi-resistant cannabis,” McKernan says, “testing for pathogen load throughout the cultivation process as opposed to just at the end is consistent with GMP. Gambling an entire crop on a single test at the end of the long growth and harvest process is not advised.”
Beyond that, McKernan joins Glauser in stressing that testing infused food and beverages for microbial contamination is done in the same manner as it is for non-infused foods, and that it should be done, whether or not FDA insists upon it.
Companies producing food products must expect to encounter pathogens eventually, says Deibel, whether FDA is testing the products or not. “Even the best company with all the right programs working in concert, they’ll still find a pathogen, Salmonella or Listeria, in their finished product, maybe once every five years—10 years if they’re lucky. But they find it. The pathogen is always waiting at your door.”