Microbials in cannabis refer to microorganisms such as mycotoxins and fungi that cause contamination and commonly appear as mold. There are health risks associated with consuming cannabis that is contaminated with microbials, particularly for immunocompromised patients. These contaminants enter the bloodstream quicker when cannabis is smoked, and even dead organisms can trigger asthma and allergies.

All cannabis sold in regulated markets is required to undergo microbial testing for organisms such as bacteria, pathogens, Aspergillus, E. coli, yeast, and other byproducts and toxins. Microbial testing practices can vary from state to state.

The best way to prevent microbial contamination is to operate a clean and sanitary grow environment, including wearing sanitary clothing in your grow space. Cannabis can still be contaminated with mold after harvest if not dried and cured properly. Some remediation may exist with the use of special UV lighting designed to kill microbes, although it may not fully destroy all mycotoxins produced from some mold spores.