When asked why Health Canada did not provide disclosure to the broader public, the department said it determined that " exposure to the affected cannabis products would not likely cause any adverse health consequences," so no wider warning was necessary.
Health Canada did not explain how it determined there was no health risk, since microbiologists and lawmakers in the United States consider there to be no acceptable level of myclobutanil in cannabis.
Sold under the name Eagle 20 or Nova 40, the chemical is used to control a pest known as powdery mildew in crops such as grapes and berries, but is also known to be employed as a shortcut by illegal cannabis grow-operations when a crop is threatened by an infestation.
Myclobutanil is permitted in small doses on certain crops that are eaten, since the chemical compounds are metabolized by the digestive system and rendered non-toxic. It is also approved for crops that don ' t retain high levels of pesticide residue as they grow.
However, cannabis is much different. Like tobacco, it is usually smoked, not eaten, so any chemicals used on the plant are often inhaled directly into the lungs, and make their way directly into the bloodstream without being metabolized, or broken down, by the digestive system. As well, cannabis, due to its unique makeup, is known to retain more pesticide residue than many edible plants.
Policy makers in the United States acted quickly to clamp down on myclobutanil use when it was discovered a few years ago, Washington state enacted emergency legislation. In Colorado, the government ordered mass recalls, raided production facilities and threatened companies with large fines. Colorado also went public with the names of producers caught using the chemical.
" Myclobutanil cleaves off hydrogen cyanide," Andrew Freedman, director of marijuana coordination for the Colorado state government told The Globe this summer. " So yeah, we were concerned."
" For us it was a pretty easy answer … If you can ' t prove it ' s safe, then we shouldn ' t allow it to go out for human consumption," Mr. Freedman said.
When Health Canada was asked by The Globe in September what the government would do if a banned pesticide such as myclobutanil was found in product grown by one of the country ' s 37 licensed medical marijuana producers, the department said it had a zerotolerance policy.
" If the Department had reason to believe that a licensed producer was using unauthorized pesticides or other chemicals, it would take immediate enforcement action," Health Canada said at the time. Such steps " could include detention of product, recalls or potentially revoking the producer ' s licence," Health Canada said, referencing two banned pesticides: myclobutanil and dodemorph.
A Globe investigation in September revealed that several unregulated cannabis dispensaries in Vancouver had sold products containing dodemorph, which is not approved " for any human use " and that Health Canada was told of the problem. However, Health Canada did not act, or warn the public, because it considers store-front dispensaries to be