Chlorpyrifos Update

On November 2, 2023, the Eighth Circuit issued a ruling vacating EPA’s final rule and sending the issue of chlorpyrifos tolerances back to EPA for further proceedings. EPA has reinstated tolerances for commodities that chlorpyrifos was registered for use for 2024. As a result, since tolerances are currently in effect, growers can now use currently registered chlorpyrifos products on all crops with reinstated tolerances, consistent with directions for use on those product labels. However, such uses may be subject to restrictions by individual states. For instance, chlorpyrifos was banned in Maryland prior to the 2022 decision and the 2023 reversal. That ban is in place.

It is extremely uncertain whether or not we will be able to use chlorpyrifos products in 2025 or on what commodities. The court ruling singled out 11 crops that labels could be adjusted. At this time, we do not have any guidance as to product use pattern legality would be in 2025. We also do not know if EPA will put in place a sunset period to use existing stocks for a period of time. USDA is putting together a list of products which are affected and labels effectively re-instated including Loveland’s ‘Warhawk’, ‘Warhawk Clearform’, and ‘Match-Up;’ Gharda’s ‘Pilot 4E and 15G’ and Drexel’s ‘Chlorpyrifos 15G, 4E, 15GR, 4E-AG2’, and ‘Lambdafos’. My understanding is that chlorpyrifos products that were available for sale prior to 2022 but not listed above (ex Lorsban) is left to individual states interpretation of what to do with existing stocks. If you are uncertain as to whether or not you can use a product not listed above, feel free to contact either of us at any time (, or Chris Wade at DDA (

Bottom line: if you are in Delaware and have a chlorpyrifos product still in storage, 2024 is going to be the best time to consider using it up should anything change in 2025 like what we saw with the tolerance revocation before the 2022 growing season.

Additional information can be found at this site: EPA Update on the Use of the Pesticide Chlorpyrifos on Food | US EPA

The Federal Register Notice can be found at Federal Register :: Chlorpyrifos; Reinstatement of Tolerances