Black market flower can also be unsafe if treated with the same chemicals. The risk with oils is that they bio-accumulate toxins during the extraction process,

Black market flower can also be unsafe if treated with the same chemicals. The risk with oils is that they bio-accumulate toxins during the extraction process, meaning the toxic PPM radically climbs as the non-cannabinoid organic material is blasted away by the CO2. The issue with both flower & oil is that black market producers cannot afford to lose a crop, so if it gets mold or pests then unscrupulous manufacturers will do whatever they have to do to salvage the season.