Rodent Control

Can synthetic pyrethroids, organophosphates insecticides, and synthetic anticoagulant rodenticides be used in organic production facilities? If so, how?

By Brian Baker

Rodents can be a serious problem for processing and handling operations. According to CalPoly food science professor Dr. Joe Montecalvo, “rodents are biological vectors for transmission of just about every microbial and viral disease.” Therefore, all operators must focus on prevention.

For organic operators, preventive practices must be implemented before any pesticides are used in accordance with §205.271. Nonsynthetics and synthetics on the National List should be used before any other substances are applied. Synthetic pesticides not on the National List may be used only when all other means prove insufficient and only with prior approval from the certifier. Finally, measures must be taken to prevent contamination of organic food by those prohibited substances.

A handler's Organic System Plan (OSP) needs to document what measures other than pesticides are being used to protect product from pests and how organic product is protected from prohibited substances. The OSP also should describe the pest monitoring practices used to determine pest control practices.

If the food is contaminated with prohibited substances after all reasonable measures to prevent contamination have been used and documented, that food can no longer be certified organic. Post-harvest handling contamination accounts for one of the top five reasons that prohibited pesticides are found in organic food—after drift and persistent soil-borne residues, but more common than deliberate fraud or sampling / lab errors.

By law, rodenticide bait stations with actives such as bromadiolone and bradiofocumin must be placed outside of food handling facilities. Operators should take care to prevent the rodents moving poison into the facility. Only non-toxic methods, such as exclusion, nest elimination and mechanical traps should be used inside a food handling facility. Rodents might have nests inside food storage areas and can move poison bait into food if they are not fully excluded.

Finally, CalPoly’s Montecalvo reminds us that “with all the concern for food safety, we in the organic industry need to be taking a leadership role in this area.”

Revised and updated in June 2017 by OMRI Technical Director Johanna Mirenda. This article was originally published in the Summer 2008 edition of the OMRI Materials Review newsletter.