Even Where Weed Is Legal, Product Safety Isn't Guaranteed

The MED has issued 97 health and safety notices since 2016. But the advisories at times include marijuana products that were sold and likely consumed months, or even years, before. That suggests either the product was contaminated at some point after it left the grow or in storage — or testing is not always finding dirty weed.

“We do see ongoing need to continue to work on that,” said Mendiola. “And ensure that we are reaching consumers effectively, that we are providing information that they ultimately need to determine: Do they have certain products that we’ve identified as a potential threat to health and safety?”

She said in recent months they updated the health and safety notice page online and will soon distribute flyers to help educate consumers on safety issues.

Mendiola acknowledged that the marijuana industry is suffering; prices for cannabis have crashed after a huge infusion of investment during the pandemic lockdowns when sales were rising quickly. Now businesses are closing, limiting license revenue that funds MED enforcement. She noted that they are downsizing their offices in Lakewood to reduce costs.

“We’ve been, for a few years now, looking at those opportunities to save costs, cut expenses, in a way that still allows us and ensures that we’re able to carry out our regulatory obligations,” said Mendiola.

Colorado marijuana growers, meanwhile, insist unequivocally that the supply is safe and that MED is active in inspecting their operations.

“I think at this point in Colorado you’re dealing with the safest weed you can have in the United States,” said Ethan Shaw, co-founder of The Flower Collective. “At the end of the day there’s a lot of things Colorado’s learned that other states haven’t learned yet, and one of those, the big one’s, heavy metals.”

Cannabis, Shaw said, is “an extreme bio-accumulator, so it takes up everything that’s in the soil and it stores it in the plant.” Research has identified heavy metal concentrations in smokable products like cigarettes, and cannabis, as a major long-term health concern.

Shaw, who said he was inspected a few months ago by the state, said anything outside of the regulated market in Colorado, like hemp-derived products, have little to no safety regulations and should be avoided.

“That is really where you need to be worried about heavy metals, mold, mildew, filth, all of these other things,” said Shaw.

Shaw also noted that the rate of recalls in Colorado has slowed, after a major increase in 2023. He said that the financial struggles of the industry in Colorado means fewer producers.

“The ones who are leftover, they’re producing [cannabis] that’s the best that you’ve been able to get in terms of consumer safety,” Shaw said.

Scientists say more consumer protections are needed

Outside experts are deeply concerned about marijuana product safety, even in the regulated market. They don’t totally blame state regulators, since there is little to no research on health impacts of different contaminants in cannabis. It’s not definitely known if any state’s testing system is looking for the right things at the right levels.

“It’s hard to make judgments on if it’s right or wrong when there’s like zero data to really go into the health impacts,” said Tess Eidem, a senior research scientist at the University of Colorado, Boulder’s lab for aerobiology and disinfection.

She said there’s some research on molds like Aspergillus, which can in rare cases lead to serious medical issues, especially for immunocompromised marijuana users. But there’s no data on how smoking versus vaping, for instance, affects the amount of contaminants that ends up in the lungs.

What is clear, said Eidem, is that marijuana growers in Colorado and other states are allowed to use irradiation technology to treat their product when it fails testing. The process is approved in food, with required labeling. She said that a grower can hit the cannabis buds with X-ray until it passes testing. The process breaks down the chemical bonds of molds and bacteria, enough for them to die or stop multiplying, according to the EPA.

The marijuana industry insists that irradiation is safe, but Eidem said there’s no research on that with cannabis.

“I think the first step there is labeling, being transparent about what has been treated,” Eidem said.

The Food and Drug Administration has endorsed irradiation as safe for food products, citing 30 years of research, but labeling is required when used. That’s not the case with Colorado cannabis, where the industry successfully fought a labeling law last year.

Because marijuana is still illegal under federal law, federal safety agencies, like the FDA, do not regulate grow operations. If they did, there would likely be rules about how the marijuana is grown — good manufacturing practices. The basic formula is that a clean facility, clean air and water, equals clean product. That’s what’s required for things like salad greens. Right now, none of that is required in marijuana in any state, not just Colorado.

“If we require that dog food follow this, but we don’t require that for cannabis — something that many people are using as medicine — to follow these kind of basic food safety guidelines, then I don’t know what the industry is doing,” said Eidem. “And I know that the industry already feels like it’s overregulated and in some ways it very much is.”

Currently, what’s required is that products pass a final test. The process can be onerous, though, on growers, who are already suffering a prolonged downturn in sales prices. Stores and grows are closing.

Shaun Opie, with E4 Bioscience in Michigan, is an expert in marijuana contaminants and lab testing. He said the money sunk into a harvest means there’s tremendous pressure to get it to market.

“The desire to have a $250,000 harvest pass (an inspection for contaminants) is very high,” said Opie.

Opie said it would be a good idea for states to implement a shelf surveillance testing program, to monitor the product that actually makes it to consumers.

Buyer beware

Thomas Mitchell reviewed cannabis products for Westword and is now an editor for the Colorado weekly. He’s written extensively on health and safety advisories and recalls issued by the state. He said it’s a buyer beware market.

“People assume it’s safe because of guardrails that are in place by state enforcement,” said Mitchell. “But when you actually look at the end result, I think that’s up for debate definitely.”

There’s a dispensary he can walk to, but he gets in his car to drive to a place that has marijuana he can trust. That’s a luxury available to someone who has deep knowledge of the industry.

“You’re not gonna keel over if you buy some cheap suspect weed,” said Mitchell. “But 10 years down the road maybe you develop a lung problem that someone who was smoking cleaner weed won’t.”