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