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Tetrachlorvinphos; Availability of Interim Risk Management Decision Document

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Environmental Protection Agency (EPA).




This notice announces the availability of the interim risk management decision document for tetrachlorvinphos. This decision document has been developed as part of the public participation process that EPA and the U.S. Department of Agriculture (USDA) are now using for involving the public in the reassessment of pesticide tolerances under the Food Quality Protection Act (FQPA), and the reregistration of individual organophosphate pesticides under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA).

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For general information contact: Demson Fuller, Special Review and Reregistration Division (7508C), Office of Pesticide Programs, Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone number: (703) 308-8062; e-mail address:

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I. General Information

A. Does this Action Apply to Me?

This action is directed to the public in general, nevertheless, a wide range of stakeholders will be interested in obtaining the interim risk management decision document for tetrachlorvinphos, including environmental, human health, and agricultural advocates; the chemical industry; pesticide users; and members of the public interested in the use of pesticides on food and pets. Since other entities also may be interested, the Agency has not attempted to describe all the specific entities that may be affected by this action. If you have any questions regarding the applicability of this action to a particular entity, consult the person listed under FOR FURTHER INFORMATION CONTACT.

B. How Can I Get Copies of This Document and Other Related Information?

1. Docket. EPA has established an official public docket for this action under docket identification (ID) number OPP-2002-0295. The official public docket consists of the documents specifically referenced in this action, any public comments received, and other information related to this action. Although a part of the official docket, the public docket does not include Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. The official public docket is the collection of materials that is available for public viewing at the Public Information and Records Integrity Branch (PIRIB), Rm. 119, Crystal Mall #2, 1921 Jefferson Davis Hwy., Arlington, VA. This docket facility is open from 8:30 a.m. to 4 p.m., Monday through Friday, excluding legal holidays. The docket telephone number is (703) 305-5805.

2. Electronic access. You may access this Federal Register document electronically through the EPA Internet under the “Federal Register” listings at​fedrgstr/​.

An electronic version of the public docket is available through EPA's electronic public docket and comment system, EPA Dockets. You may use EPA Dockets at​edocket/​ to submit or view public comments, access the index listing of the contents of the official public docket, and to access those documents in the public docket that are available electronically. Although not all docket materials may be available electronically, you may still access any of the publicly available docket materials through the docket facility identified in Unit I.B.1. Once in the system, select “search,” then key in the appropriate docket ID number.

II. What Action is the Agency Taking?

EPA has assessed the risks of tetrachlorvinphos and reached an Interim Tolerance Reassessment Eligibility Decision (TRED) or a Report on FQPA Tolerance Reassessment Progress and Interim Risk Management Decision for this pesticide. With risk mitigation measures adopted, tetrachlorvinphos fits into its own risk cup-its individual, aggregate risks are within acceptable levels. The RED for tetrachlorvinphos was completed in 1995. At that time, the Agency assessed the risk for dietary, occupational, ecological, and residential concerns. With the passage of FQPA, the tolerances for tetrachlorvinphos needed to be reassessed according to the FQPA safety standard. In this current assessment, the Agency looked at dietary, residential and occupational concerns.

Tetrachlorvinphos is currently applied dermally to livestock to control flies and mites; used as a feed-through (oral) larvicide in cattle, hogs, goats, and horses; in cattle ear tags to control flies; and in poultry production to control beetles, flies, and mites. Tetrachlorvinphos also is used as a dust/powder, aerosol, and pump spray on pets and in pet sleeping areas, and in collars and shampoos for direct treatment of pets. It is used as a spray to control nuisance and public health pests (flies) in and around refuse sites, recreational areas, and for general outdoor treatment.

Dietary risks from eating food items containing residues of tetrachlorvinphos are below the level of concern for the entire U.S. population, including infants and children. Drinking water is not a significant source of exposure. Residential handler and post application risks were also not of concern for all exposure scenarios. However, the Agency has concern over Start Printed Page 77492the potential for over-application of powder products. Labels need to be modified to specify how much product to apply to treat pets of different sizes. Additionally, based on discussions with stakeholders, EPA believes that directions for outdoor uses as premise sprays around kennels, yards, campgrounds, and parks, and along foot paths and roadways leading to such areas, must clearly limit use to spot treatments only.

Worker risks for most scenarios are not of concern if measures to reduce exposure, such as personal protective equipment, are used. However, use of the EC formulation as a paint-on poses high risks to workers despite the maximum protection feasible. Therefore this use will be removed from product labels. For other scenarios, such as applying dusts with power dusting equipment, additional data are needed to confirm that risks to workers will not be excessive.

In addition, EPA has determined that labels for tetrachlorvinphos feed-through products for horses must state that the product is a chlolinesterase inhibitor, describe signs of cholinesterase inhibition in horses, caution against the use with other cholinesterase inhibiting compounds, and direct horse owners to consult a veterinarian before using products containing tetrachlorvinphos on debilitated, aged, breeding, pregnant or nursing animals.

The interim risk management decision document for tetrachlorvinphos was made through the organophosphate pesticide pilot public participation process, which increases transparency and maximizes stakeholder involvement in EPA's development of risk assessments and risk management decisions. The pilot public participation process was developed as part of the EPA-USDA Tolerance Reassessment Advisory Committee (TRAC), which was established in April 1998, as a subcommittee under the auspices of EPA's National Advisory Council for Environmental Policy and Technology. A goal of the pilot public participation process is to find a more effective way for the public to participate at critical junctures in the Agency's development of organophosphate pesticide risk assessments and risk management decisions. EPA and USDA began implementing this pilot process in August 1998, to increase transparency and opportunities for stakeholder consultation.

EPA worked extensively with affected parties to reach the decisions presented in the interim risk management decision documents, which conclude the pilot public participation process for tetrachlorvinphos. As part of the pilot public participation process, numerous opportunities for public comment were offered as these interim risk management decision documents were being developed. The tetrachlorvinphos interim risk management decision document therefore is issued in final, without a formal public comment period. The docket remains open, however, and any comments submitted in the future will be placed in the public docket.

The risk assessments for tetrachlorvinphos were released to the public through a notice published in the Federal Register of January 15, 1999 (64 FR 2644) (FRL-6056-9) and March 27, 2000 (65 FR 16197) (FRL-6551-4). Addenda to these assessments are also available in the public docket.

EPA's next step under FQPA is to complete a cumulative risk assessment and risk management decision for the organophosphate pesticides, which share a common mechanism of toxicity. The interim risk management decision document on tetrachlorvinphos cannot be considered final until this cumulative assessment is complete.

When the cumulative risk assessment for the organophosphate pesticides has been completed, EPA will issue its final tolerance reassessment decision for tetrachlorvinphos and further risk mitigation measures may be needed.

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List of Subjects

  • Environmental protection
  • Chemicals
  • Pesticides and pests
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Dated: December 3, 2002.

 Lois A. Rossi,

Director, Special Review and Reregistration Division, Office of Pesticide Programs.

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[FR Doc. 02-31361 Filed 12-17-02; 8:45 am]