Pesticides present a unique challenge to the cannabis industry. There are dozens of industrial pesticides on the market, but there are no federal guidelines for use on cannabis, although there are now a limited number registered with the Environmental Protection Agency for federally legal hemp.

With each state setting its own limits on pesticides, growers and testing labs alike have to be ready to meet the standards. And the stakes are high: Pesticides are hazardous to human health, and going over a pesticide action level can result in the destruction of an entire harvest. Additionally, the extraction process may raise levels of pesticide compounds in the final product, similar to the ways in which heavy metals become concentrated after processing. So even if the plant material used for extraction had been tested and approved, the final extract can still have levels of pesticides higher than acceptable limits.