To be federally legal in all States, CBD (cannabidiol) oil must contain less than 0.3 percent of the psychoactive ingredient THC (tetrahydrocannabinol).
But though a CBD oil may contain less than trace amounts of THC at the time it is put on the market, will this still be the case when the oil is in the hands of the user?
This was the subject of a recent study in Cannabis and Cannibinoid Research and the results are not entirely reassuring.
It was already known that CBD stored in an acidic environment can undergo some chemical changes that result in levels of THC being boosted. The new study, by researchers from the University of Modena in Italy, analysed both synthesized and hemp-extracted CBD samples at day one, and again after three months of continuous use, while being stored on the laboratory bench-top at room temperature in the dark (the storage conditions as specified on the label).
At the beginning of the study, the samples, which were analysed using a liquid chromatography-based method coupled to a high-resolution mass spectrometry detector, found no detectable THC. But after three months, several discernible peaks appeared on the chromatogram, two of which were found to be both forms of THC—chemically speaking D9-THC and D8-THC.
The authors surmise the presence of carbon dioxide and moisture led to the conversion of small amounts of CBD to THC.
As it was, even in the worst case scenario the researchers only detected THC at a level of 0.15 per cent, which is half the maximum allowed in products legally for sale.
But If the amount of THC impurities in stored CBD extracts turned out to be significant, this could have implications for the commercial producers of CBD products.
The authors say the results warrant CBD oil suppliers thinking about how they recommend storage of their product on the label. The study suggests that the best place for storage is not just in the dark, but also in the fridge at a temperature of no more than of 4–8°C (39°F–46°F).
