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Innovations in Irradiation: How in-house irradiation tech can increase control over end product

In a dynamic discussion on the intricacies of microbial testing and irradiation technology in the cannabis industry, two experts shed light on the challenges and opportunities facing producers in Canada and beyond

February 20, 2024  By Justin Czerniawski and Dion Cimini

Photo: Adobe Stock

PhD scientist and researcher Justin Czerniawski, VP of R&D for Rad Source Technologies, speaks to a current shift happening in cannabis, from centralized irradiation facilities to smaller, in-house units enabling more control over the final product.

A recurring theme he has heard within the cannabis industry is a reluctance towards shipping flower out for testing due to unwanted changes to the product’s composition. The logistics alone are complicated, says Czerniawski, from a security perspective as well. For this reason, there’s now an increasing demand in North America for standalone irradiation technology, especially among craft or boutique-sized cannabis producers.

GO: When it comes to irradiating cannabis, what are the differences between in-house vs. third party testing?

JC: In Canada, gamma facilities or e-beam are giant, centralized facilities that are used to irradiate, not just cannabis but food and even pharmaceutical products. So these are giant facilities where you load pallets that get wheeled through automatically, the products are exposed and the exposure is far greater than a standalone smaller unit. The exposure is well over 10,000 gray in many instances – gray is a unit of measure that we use.

GO: What happens at third party irradiation labs?

JC: What happens is you have certain batch sizes that you send in, and then you lose control of your product and it’s getting exposed to a lot more radiation than you probably want.


For instance, if it’s shipping in a truck, maybe it’s summertime and the truck gets warm; you’re losing terpenes and LPs no longer have physical control over it.

GO: What is the smallest unit that can be used while still maintaining compliance?

JC: Some people are running 2,000 to 2,500 gray, not over 10,000. And then they can make sure they’re in a controlled environment. They can operate safely on site without having to worry about customer, employee, or product safety. The wavelength itself is tuned to fight the microbes, and that’s it. It affects the DNA of the microbes and once the DNA is destroyed, the microbe itself self-destructs and it’s no longer viable.

GO: Are the cannabinoids and terpenes at larger facilities being damaged?

JC: It’s just as likely, if not more likely, that the damage to the terpene profiles and cannabinoids is actually happening in transit. There’s so much unknown when you lose control over the product, why even take that chance?

The nice thing about the radiation machine is since it’s specifying the use of mould, we can actually get it down to “too few to detect.” Sometimes a product has been on a shelf for sometimes a week, sometimes a month. We’ve seen a lot of recalls where people have gotten their testing levels just under the threshold, but because they’re still viable – total yeast and mould – it’s grown back when it’s retested. Too few to detect is going to be vital, especially in strict markets like Germany.

We’re starting to see higher levels of processing, not necessarily industrial processing, we’re seeing it more like boutique processing – that really seems to be the market.

InBev might own the craft brewer, but the craft brewer still controls their recipe; a similar structure seems to be going on in the cannabis space.


Rad Source Technologies representative Dion Cimini began growing in the legacy market from his home state of Michigan 14 years ago. He’s now spent the last three years working in microbial decontamination with Rad Source and his knowledge of the industry on both sides of the border remains strong. When navigating the different Pharmacopoeia standards that producers need to meet for testing microbials, differing limits must be adhered to depending on jurisdiction.

GO: What is the current microbial limits in Canada?

DC: In Canada, they allow the licensed producer the option to decide which Pharmacopoeia USP that they want to inherit as part of their quality assurance. In Canada domestically speaking, the easiest one is 5.1.8 Table C. You can choose from any of the ones you want.

Now, some distributors might want to see cannabis at a different level, which might be 5.1.8 Table B. But most of the time domestically they’ll be going with C because it’s 50,000 Cfu yeast and mould, it’s 500,0000 Cfu at anaerobic microbial and bio tolerance under 10,000 Cfu.

When you look at Table B, your yeast and mould drops to 500 Cfu, your aerobic bacterial drops to 50,000. And then your bio tolerance goes down to 100. Anybody who can pick and choose their testing standard, they’re going to pick the easiest one.

Now for outdoor growers, even though some of those are actually tough, 50,000 for your yeast and mould, well that’s tough for an outdoor grower; that’s hard for a greenhouse grower.

GO: How about shipping internationally?

DC: If you were to sell your product into Germany today, now you have to follow the EP 5.1.4, which is 10 Cfus for your total yeast and mold, 100 on anaerobic, and then less than one or absent in one millilitre biotolerant gram negative bacteria. It’s all over the place in other words.

GO: How is a lack of microbial standardization causing issues in the industry?

DC: Hopefully we’ll get some clarity with this new review. I know that it’s an issue because it is all over the place.

Canada, domestically, you can choose, but mostly they’re used the European Pharmacopoeia 5.1.8 or 5.1.4. There’s no standardization of how to test the product. Every lab in Canada is testing product differently. Some are homogenizing, some aren’t. That’s why you see some elevated THC results because they’re not being tested correctly. And they’re being tested into to the to the advantage of the grower.

GO: How are different growing methods and mediums affecting the end product?

DC: It’s all based on climate control. When you’re outdoors or in greenhouse, you’re exposed to the outside; it’s harder to control than it is in an indoor environment. Also mediums, so growing in water versus soil, soil is probably going to increase your likelihood of getting more microbial if microbial is live in the soil.

If you have active organic soils, the same thing, but it really just depends on the control. You could have soil and then put perlite on the top to prevent any kind of bacteria or microbials from getting onto the plant or blowing into the air.

GO: What are the benefits of an in-house irradiation unit?

DC: It’s a better technology because it’s not as hard to operate and you can control the gray levels. There’s also a lot of heat on e-beam. With these machines, you control the heat. It has a chiller hooked up to the unit and you can control different temperature ranges. The lower the temperature, the lower the impact on the product. Having the temperature dialed in is not something you’re able to do that when you send it to a traditional gamma or e-beam facility.

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