Cannabis irradiation poses quandary for growers, scares consumers

Did you miss the webinar “Women Leaders in Cannabis: Shattering the Grass Ceiling?” Head to MJBiz YouTube to watch it now!


Image of a cultivation worker

Cannabis cultivators are caught in a dilemma about providing clean, safe product that passes inspection for acceptable levels of microbial contaminants.

The standard solution is irradiation: gamma rays zapping cannabis flower with the highly charged, radioactive element cobalt 60.

Is irradiation good? Is it bad? Should cultivators even admit to doing it?

Some of the confusion comes from state regulators, who are still figuring out what microbes to guard against from a list of the plant’s typical microbial contaminants.

If they don’t pass testing – generally because of bad microbial growth due to poor sanitation in the grow and processing stages – growers will have to nuke it.

But who wants nuked cannabis?

The fact is that state-regulated cannabis often has been blasted by gamma radiation for hours – or by electron beam radiation, or, the preferred method by U.S. cultivators, x-ray radiation – to kill bad microbes.

One microbe in particular, aspergillus, which is present everywhere, can cause serious respiratory illness and even death – not only among consumers but also cultivation workers.

Gamma irradiation is an old-school tool.

It’s the same sort of radiation used for many food products sold in the United States. The U.S. Food and Drug Administration lists nine food varieties that can be radiated, including beef and pork as well as fresh fruit and vegetables including lettuce and spinach.

At least 59 other countries irradiate their foods because it is considered an effective form of food preservation that extends shelf life by reducing spoilage – albeit with a slight reduction in vitamins.

But most cannabis cultivators don’t want you to know their product has been zapped.

U.S. cannabis growers who use radiation have made efforts to dodge the stigma by calling irradiated cannabis “electronically pasteurized” or “cold pasteurized.”

But irradiation has become a part of standard operating procedures (SOPs) because it penetrates the plant well without causing undue damage – unlike other plant decontamination methods using heat, chemical reagents or even toxic substances such as ethylene oxide gas.

When their cannabis fails testing, cultivators zap it, sell it to the public and hope for the best.

There’s some evidence that even zapping can end up leaving bits of disconnected DNA intact, which can help the microbe “revive itself,” according to Jini Glaros, chief scientific officer at Modern Canna Laboratories in Lakeland, Florida, who called for more investigation into that possibility.

The problem with eliminating bad microbes

Getting rid of microbial contaminants in cannabis has always been a dodgy exercise for a federally illegal product.

“All of the infrastructure – the good manufacturing practices, the good agricultural practices and the product safety that is required in manufacturing these other consumer food goods – is not required for cannabis manufacturing,” Tess Eidem, a microbiologist with Denver cannabis consultancy Rogue Micro, told MJBizDaily.

“Your dog food is regulated by the FDA, unlike cannabis,” she noted.

“With cannabis, you really don’t have to put in any preventive controls. You don’t have to have a sanitation program. You don’t have to have a quality team.

“All of the food safety that manufacturers in the food industry are expected to do and proactively address to identify their risks and their food-safety plans are not required in cannabis,” Eidem said.

“All cannabis manufacturers really have to do is pass compliance testing.”

Passing testing can mean up to 24 hours of product sitting in an irradiation machine, Eidem said.

“In the short term, a cultivator can recover failed products (by remediation). But in the long term, it’s a crutch – and it’s not really solving the underlying issues.”

Suehiko Ono, founder and CEO of EOS Farms, a family-owned organic cannabis farm in Pittsfield, Massachusetts, irradiates cannabis as a way to be compliant with the strict and broad analysis requirements for cannabis sold in Massachusetts.

“The microbe testing threshold comes from extreme fear and caution on the side of regulators,” Ono told MJBizDaily.

“The basic approach and attitude from regulators is: Do something even if it does nothing, because you can’t do nothing – even if what you’re doing doesn’t really do anything but confuse the matter. But you have to protect the consumer.”

Microbe testing thresholds in the state are “both over-determinative and under-determinative,” he said.

“(They’re) over-determinative in that they test for any of the millions of species of total viable aerobic bacteria and total yeast mold. They don’t differentiate,” Ono said.

“They test for the presence. And they don’t test for aspergillus, which is the only one that’s been shown to cause harm. They don’t even tell you if it’s there or not.

“So, if we’re going to force these nonsensical microbe-testing thresholds, then you’ve got to remediate. There’s no way around it.”

A different approach abroad

It’s a different scenario outside of the United States.

Canadian cannabis producers routinely irradiate an estimated 80%-90% of their product.

All medical cannabis imported into Germany must be irradiated in a laboratory that is compliant with that country’s strict requirements.

In the Netherlands, where medical marijuana is available to patients through a prescription by a qualified doctor, the Dutch government controls the irradiation process.

Irradiation is the preferred method of decontamination in the Netherlands, according to a 2016 study by Arno Hazekamp, the former head of research and education for Dutch cannabis producer Bedrocan International.

Medical cannabis can’t be sold within the Netherlands until the country’s Ministry of Health certifies the product as irradiated.

Concerns among adult-use consumers

Most of the fears about irradiation in the cannabis industry come from recreational consumers who are not well informed, according to Tjalling Erkelens, the founder and board chair of Bedrocan.

The producer of medicinal cannabis follows European guidelines for good manufacturing practices.

Irradiation does not destroy the cannabinoids in the plant, Erkelens told MJBizDaily, dispelling one common myth about irradiation.

“It very slightly affects terpenes,” Erkelens said.

“There’s no degradation of THC or CBD. If the product is properly packaged, there’s no loss of water. Basically, nothing changes.”

Erkelens said he has heard the unfounded fears that gamma radiation is not good for patients using medical cannabis.

“What’s that about? What’s the scientific basis for that? Please prove to me that this is bad for patients,” he said.

“There’s no remainder of the irradiation process itself (in the cannabis). The only thing it does is it cuts actually the string of life in living creatures, of living spores and living bacteria.

“It’s why I don’t like those machines that process cannabis flowers, because there are no eyes on the end products. So, the risk of getting mold in the product is there.”

Erkelens’ general recommendation to avoid bacteria in the product is to treat the indoor grow facility like a hospital.

“You should wash your walls and your floor,” Erkelens said. “It should be embedded in protocols and done on a very regular basis.

“And when you go in to where the plants are flowering, be sure that everything you bring in there is clean. Even be sure to bring in clean air.”

That same clean-room recommendation is echoed by Kyle Baker, co-founder and chief strategist of EcoBuds, a biosecurity company based in Carbondale, Illinois.

“If I tell the client that they need to clean every day, sometimes twice a day, and that was the answer to their problem of failing tests, they look at me cross-eyed,” he told MJBizDaily.

“But if they do it, they don’t have to use radiation. They don’t have to use remediation methods. Because the consistency of not having disease issues that affect yield are significantly decreased.”

Next steps

The real problem is that a young industry is still getting a handle on regulations, Modern Canna’s Glaros told MJBizDaily.

“It’s a little weird that we’re not letting consumers know when a product has been irradiated,” she said.

“I know that regulations aren’t requiring producers to label that they’ve irradiated their product, and so that’s not happening on that side of it.

“I think the regulations are being created before we have all of the information.”

“That’s not necessarily anyone’s fault,” Glaros said. “It’s just that this is such a new industry in a way.

“We’re still in its infancy compared to the food industry and the pharmaceutical industry.

“Hopefully regulators are listening to the people doing the research and seeing the data and making changes to those regulations based on that information.”