The rules governing the implementation of I-502 limit pesticides that may be used to produce recreational marijuana. The Washington State Liquor Control Board (WSLCB) and the Washington State Department of Agriculture (WSDA) recently produced the list of acceptable pesticide products.
Only authorized pesticide products may be used. Using an unauthorized pesticide is a public safety license violation and can result in the cancellation of a producer’s license (see WAC 314-55-520).
WAC 314-55-010(13) defines a pesticide as meaning, but is not limited to: (a) Any substance or mixture of substances intended to prevent, destroy, control, repel, or mitigate any insect, rodent, snail, slug, fungus, weed, and any other form of plant or animal life or virus, except virus on or in a living person or other animal which is normally considered to be a pest; (b) any substance or mixture of substances intended to be used as a plant regulator, defoliant, or desiccant; and (c) any spray adjuvant. Pesticides include substances commonlyreferred to as herbicides, fungicides, and insecticides.
Licensed producers can use pesticides registered by WSDA under chapter 15.58 RCW that are allowed for use in the production, processing, and handling of marijuana.
If a particular pesticide is not consistent with the allowable pesticide criteria WSDA uses for marijuana production, the applicator could unknowingly be in violation of Washington pesticide laws (RCW 15.58.150(2)(c) and WAC 16-228-1500(1)(b)). We recommend that pesticides from the OMRI list be cross-checked with the list of over 200 pesticides registered by WSDA that are allowable for use in marijuana production in PICOL.
A preliminary list of over 200 pesticides registered by WSDA under chapter 15.58 RCW that are allowed for use in the production, processing, and handling of marijuana can be found at Washington State University’s (WSU) PICOL (Pesticide Information Center Online) database at:
Under the “crop” drop-down menu choose: “I-502/I-692 (WA Only).”
PICOL lists the regulatory status of pesticides, as determined by WSDA. Updates can be made on a daily basis as pesticides are registered (and cancelled) by WSDA.
WSU has prepared tutorials as a starting point for prospective marijuana producer applicants in using the PICOL database.
- Basic Tutorial for Using PICOL database: This site will assist you in your search for products for the control of a pest or pests commonly found in the production of marijuana. “How to Run a Search” begins on page 5 of 12.
- I-502 Specific YouTube Tutorial: This video is specific to PICOL and I-502.
If you have any questions, please contact the WSLCB Marijuana Licensing Unit at firstname.lastname@example.org.