Chlorpyrifos--Tolerance ghosts haunt EPA

Jane Thomas, Pesticide Notification Network Coordinator, WSU

The Environmental Protection Agency discovered earlier this year that, for more than a decade, 35 to 40 chlorpyrifos-containing products had been registered for use on popcorn and carrots (including seed) but that no tolerance existed for these uses. Not only were there no tolerances currently on the books, there never had been. In the March 18 Federal Register, EPA announced that popcorn and carrot uses were being deleted from six technical grade products and that the agency was waiving the standard 180-day comment period. Because of this waiver, the use deletions went into effect the following day.

According to Margery Exton of the Office of Pesticide Programs, EPA is currently working to get the holders of approximately 40 manufacturing use registrations to revise their labels and delete these uses. The final step in clearing up the problem will be to have the 35 to 40 end use product labels revised.

At the time of the initial Federal Register notice, the Washington State University Pesticide Information Center conducted a search for chlorpyrifos products currently registered for use in Washington on carrots and popcorn. No products were found to be registered for use on carrots; however, several exist that are labeled for popcorn use. These are:

Nufos 15G Cheminova 67760-14
Nufos 4E Cheminova 67760-28
Lorsban 15G Dow Agrosciences 62719-34
Lorsban 4E Dow Agrosciences 62719-220 or 62719-23
Chlorfos 15G Grffin 22-18-1812
Chlorpyrifos 15G AG Micro Flo 51036-234
Chlorpyrifos 4E AG Micro Flo 51036-244

Dr. Tina Levine, chief of the Insecticide-Rodenticide Branch of EPA's Registration Division, said that EPA has little planned regarding use of chlorpyrifos on carrots or popcorn. This includes crops under production, post-harvest, or in channels of trade. It will no doubt be several months before chlorpyrifos product labels are revised to delete these uses and much longer before all product labeled for these uses is off the shelf. Dr. Levine said that about all EPA can do is ask the FDA to exercise enforcement discretion regarding this matter.

The issue may all come down to an "oh, never mind," because the initial EPA action was not triggered by FDA finding carrots or popcorn containing illegal chlorpyrifos residues. Apparently, although this situation has existed for about a decade, FDA has never found carrots or popcorn containing detectable residues of chlorpyrifos.

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