The Office of Administrative Law this week approved a regulation that exempts from registration the biopesticide chitosan, which is an alternative to more-conventional insecticides and fungicides. The regulation was proposed by the Department of Pesticide Regulation (DPR) in January 2025.

The regulation, which went into effect on Aug. 13, amends section 6147(a)(5)(A) of title 3 of the California Code of Regulations, adding chitosan to the list of active ingredients permitted in exempted pesticide products.

The exemption means that manufacturers, importers, and dealers will no longer need to obtain a certificate of registration from DPR before selling the products for use in California.

Chitosan is a naturally occurring substance found in the shells of crustaceans, exoskeletons on insects, and the cell walls of many fungi. It can be used to combat harmful fungi and insects on plants, and also has properties as a plant growth regulator.

DPR’s action follows U.S. EPA’s 2022 designation of chitosan as a “minimum risk pesticide,” exempt from registration requirements because it poses little or no risk to human health or the environment.

The final regulation text and other rulemaking documents concerning the department’s chitosan regulatory action are available on our website.