(Beyond Pesticides, December 12, 2007) On December 5, 2007, the US Environmental Protection Agency (EPA) denied the petition filed on June 2, 2006, by the Natural Resources Defense Council (NRDC) to revoke pesticide tolerances for dichlorvos (DDVP) established under Section 408 of the Federal Food, Drug, and Cosmetic Act, finding the petition to be â€świthout merit.â€ť According to the petition filed, the NRDC asserted that DDVP tolerances are unsafe and should be revoked for numerous reasons, including: (1) EPA has improperly assessed the toxicity of DDVP; (2) EPA has erred in estimating dietary and residential exposure to DDVP; and (3) EPA has unlawfully removed the additional safety factor for the protection of infants and children. The EPA, in its response says that the toxicity of DDVP is not a sufficient ground for seeking revocation of tolerances. NRDCâ€™s petition argued that DDVP should not have been downgraded from â€śprobable human carcinogenâ€ť to â€śpossible human carcinogen.â€ť But EPA found the studies cited to be inadequate to support an amendment in classification, and as such the petition to revoke tolerances to the extent based on the alleged cancer misclassification of DDVP was rejected.
The petition also challenged that various exposure studies used to evaluate chronic end points such as neurotoxicity and mutagenicity were inadequate for assessing risk in humans. However, the EPA contended that its assessment of the studies used, outlined in the registration documents for DDVP, utilized acceptable scientific techniques for evaluating exposure. The EPA also upheld DDVP tolerances and safety factors, which were cited by the NRDC as unsafe.
Despite this defeat, the NRDCâ€™s petition prompted an update to the DDVP dietary exposure and risk assessment first incorporated in the 2006 Interim Regisitration Eligibility Decision (IRED), to include residues for drinking water, an updated monitoring and crop data program and the incorporation of estimated exposure from the use of naled as a wide area treatment for mosquitoes. The IRED was released after the petition was filed. A DDVP Special Review is currently open and will be formally concluded later in December, as risk concerns that prompted the review have since been mitigated or eliminated, according to the EPA.
In February 2007, the NRDC again filed a lawsuit against the EPA for failing to ban DDVP and carbaryl. NRDC has also contended that pesticide industry lobbyists llegally negotiated with the EPA for favorable pesticide regulation.
Currently used in pest strips, aerosol sprays and pet collars, DDVP is one of a class of the most dangerous pesticides, called organophosphates, which derive from World War II-era nerve agents. Studies have shown DDVP causes cancer in laboratory animals. California lists DDVP as a known carcinogen, while the World Health Organization lists it as a possible human carcinogen. According to NRDC, DDVP is already banned overseas, including the United Kingdom, Denmark and Sweden.
To read EPAâ€™s decision, visit http://www.epa.gov/fedrgstr/EPA-PEST/2007/December/Day-05/p23566.htm and http://www.epa.gov/fedrgstr/EPA-PEST/2007/December/Day-05/p23571.htm. Objections to this decision and requests for hearings must be received on or before February 4, 2008. For more information, please contact Susan Bartow, Special Review and Reregistration Division (7508P), Office of Pesticide Programs, Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone number: (703) 603-0065; e-mail address: email@example.com.