Any plant product is subject to microbial contamination from soil, air and water. In cannabis, microbial contamination is mainly because of aerobic bacteria, enterobacteria (e.g. E. coli, Salmonella), yeast and mould (fungi).
The presence of these contaminants is influenced by environmental factors such as temperature, humidity, harvesting, handling and storage.
In order to maintain the appropriate quality and safety of these natural products, growers and producers need to ensure the lowest possible level of contamination.