James Duckenfield, CEO of Glass Pharms®, examines what irradiation adjustments in medical hashish flower, what it leaves behind, and why understanding microbial high quality requires a more in-depth take a look at the science.
A lot of the dialogue involving irradiated medical hashish centres on whether or not the remedy impacts THC or terpenes. These are cheap questions, however I feel the microbiology deserves an equal share of the eye.
Irradiation can considerably scale back the variety of viable microorganisms in flower, however any mould that has already grown stays bodily current after remedy.
Cautious cultivation, hygiene, and post-harvest dealing with assist forestall that progress from occurring within the first place. Testing permits producers to test that these controls are working, whereas drying and storage situations decide whether or not surviving microorganisms have the chance to multiply as soon as the batch of flower has been harvested. Irradiation must be understood inside that wider course of.
What does irradiation do, and what does it go away behind?
Ionising radiation damages microbial DNA and different mobile buildings, stopping affected organisms from reproducing. Gamma remedy, electron-beam remedy, and X-ray remedy ship that vitality in several methods. None makes the flower radioactive.
The effectiveness of remedy depends upon the dose, the organisms being focused, and the situations below which it’s utilized. Analysis on medical hashish has demonstrated reductions of over 99.9% in viable fungal counts following irradiation, with electron-beam remedy attaining round 99.999% below the situations examined. This sounds nice till you respect that this doesn’t imply sterilisation.
For flower initially containing ten million colony-forming models per gram, a 99.999% discount would go away roughly 100 CFU/g. By that measure, the remedy is very efficient, however it doesn’t make the flower sterile.
Crucially, these exams measure viable microorganisms able to forming colonies below laboratory situations, not the overall quantity of fungal materials remaining within the flower. Hyphae, spores and fungal fragments should still be current, together with materials able to scary allergic reactions. And because the US Environmental Safety Company explains, mould can stay allergenic even when useless.
A low viable depend can not, by itself, display that medical hashish flower is free from the residues of earlier mould progress, together with aflatoxins.
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What does the analysis present about handled flower?
THC and CBD seem comparatively secure below the irradiation situations studied thus far. Terpenes, the risky compounds accountable for a lot of the flower’s aroma, have proven extra variable outcomes.
One ought to be cautious about translating both end result right into a declare about how effectively a drugs works. These had been laboratory measurements, and they don’t set up any variations in symptom aid between irradiated and non-irradiated medical hashish.
There may be additionally the query of gear produced by mould earlier than remedy. Some fungi produce mycotoxins, that are chemical compounds moderately than residing organisms. In a 2025 examine, researchers detected residual mycotoxins and recovered viable fungi after gamma irradiation, regardless of substantial reductions in microbial counts. The findings apply to the samples and remedy studied however illustrate why testing for viable fungi and testing for his or her toxins reply completely different questions.
Why do microbial requirements and prevention matter?
Traditionally, the overwhelming majority of medical hashish flower prescribed within the UK has been imported, with Canada amongst its principal suppliers. UK cultivation, together with our work at Glass Pharms, is starting to broaden that offer. Variations in microbial requirements between international locations stay related to how imported flower is ready for UK sufferers.
Well being Canada accepts herbal-product microbial requirements for dried hashish supposed for smoking or vaping. These can allow larger yeast-and-mould counts than the inhalation normal the MHRA expects UK imports to align with, and deviations require justification. A batch that meets its authentic home specification might due to this fact want further remedy earlier than it meets the specification utilized for UK provide.
Completely different microbial specs allow completely different counts in flower. The 4 dishes under illustrate the size of these variations, from the decrease counts permitted below the inhalation normal to the upper counts accepted below some herbal-product and Canadian hashish specs.
Illustrative comparability of accelerating microbial counts that may happen in hashish flower. To not scale.
Irradiation can present that microbial discount. Its implementation doesn’t inform us the ultimate fungal depend, nevertheless, simply as a non-irradiated label doesn’t set up {that a} batch meets any specific normal. Each require the identical stage of regulatory oversight and testing.
The flower should then stay secure throughout transport and storage. Any surviving microorganisms nonetheless have vitamins obtainable and will multiply if enough water turns into obtainable. Producers want to regulate water exercise, a measure of the water obtainable for microbial progress, by drying and preserve it at a sufficiently low stage throughout packaging and storage. Irradiation doesn’t take away that requirement.
At Glass Pharms, we don’t irradiate our medical hashish flower. We work to forestall contamination by strict hygiene and regulatory practices throughout cultivation and dealing with, use managed drying and curing to restrict water obtainable for microbial progress, and check all through cultivation and post-harvest processing to confirm these measures are efficient.
