Pesticides and Cannabis: Background on Potential Health Risks

In 2012, Washington voters approved I-502 and legalized adult use of cannabis. Because cannabis is still illegal under federal law, regulation of the industry falls under state jurisdiction and is not subject to the federal system for evaluation and oversight of pesticides.

Our state’s Liquor and Cannabis Board (LCB) currently allows the use of more than 200 different pesticides, even though the health effects from inhaling or ingesting pesticides on cannabis and cannabis products are unclear. However, the LCB also expressly prohibits 13 different pesticides, which are listed here. Despite this fact, the LCB does not regularly test cannabis products for the banned pesticides.

The LCB recently imposed fines on two major Washington cannabis producers for using prohibited pesticides. The violators were only discovered through consumer complaints and public-record requests, not as a result of oversight by the LCB. Reports indicate that banned pesticides may be in use in the legal cannabis system. The LCB relies primarily on producer self-reporting and on-site random inspections without also requiring pesticide testing of the consumable product. As a State Senator, I introduced a bill that would have required mandatory pesticide testing by the LCB. Unfortunately that requirement was not included in the final bill, so it’s up to consumers, patients, elected officials and the media to press for mandatory pesticide testing of all marijuana products.

The U.S. Environmental Protection Agency (EPA) has not yet approved any pesticides for the production of cannabis, although it has offered to fast-track the research and testing in this area. As of yet, no state, including our own, has accepted the EPA’s offer. Since cannabis is still a federally-prohibited product, there are no established guidelines for determining safe pesticide levels.

This issue is particularly important for medical marijuana patients, who may be dealing with compromised immune systems or are otherwise medically vulnerable. I am deeply concerned about possible adverse health effects and am working to protect consumers from potentially hazardous pesticides used in the growing of cannabis. My Seattle Times Op-Ed last March helped spur the continued investigation and regulation of the chemicals used in the farming of cannabis.

Another problem is the LCB’s inadequate regulation of the state’s cannabis testing labs. An independent analysis by Dr. Jim MacRae showed wide variation between the labs’ results — some labs never find contaminated product and other labs find contaminated product nearly half the time. The LCB has no system in place to ensure consistent testing and compliance with the law.

Dr. Jeff Duchin, King County’s public health officer, has said, “Because marijuana is often smoked or vaped and little is known about the effects of inhaled pesticides, it is important to learn more about the health effects of pesticide exposure both through inhalation as well as through ingestion of marijuana products.”

King County government is limited by state law, so our communities have to rely on the LCB and other state agencies to ensure safety for cannabis consumers and patients.

On September 15, I introduced legislation at the County that would require testing of marijuana products for prohibited pesticides. Recently, the LCB has been responding to calls for the testing of pesticides in legal marijuana sold at licensed I-502 stores in our state.

The LCB’s plan to work with the Washington State Department of Agriculture to randomly test products and to test samples after consumer complaints appears to help this new industry begin to provide safer cannabis products. However, I believe testing could be conducted more readily by independent labs that already have the capacity and experience.

I plan to continue my efforts in working with producer/processors, retailers, and labs to determine if the County should have a role in ensuring product safety. I will work with these groups and the state to ensure that consumers in King County can have confidence that the products they purchase are tested and safe.

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