United States
                      Environmental Protection
Prevention, Pesticides
and Toxic Substances
September 2000
SERA     Phostebupirim  Facts
               EPA has assessed the dietary risk of phostebupirim [also known as tebupirimphos] and
        prepared a Report on FQPA Tolerance Reassessment Progress and Interim Risk Management
        Decision for this organophosphate (OP) pesticide. Phostebupirim fits into its own "risk cup"-- its
        individual risks are within acceptable levels.
               Because phostebupirim was initially
        registered after 1984, it is not subject to
        reregistration. However, the Agency has
        reassessed the occupational risks from
        phostebupirim use on com and is
        recommending label modifications at this time.
        In addition, the registrant is generating
        additional data which will be used to refine the
        occupational risk assessment.

               EPA's next step under the Food
        Quality Protection Act (FQPA) is to complete
        a cumulative risk assessment and risk
        management decision encompassing all the OP
        pesticides, which share a common mechanism
        of toxicity. The interim decision on
        phostebupirim cannot be considered final until
        this cumulative assessment is complete. Further
        risk mitigation may be required at that time.

               EPA is reviewing the OP pesticides to
        determine whether they meet current health and
        safety standards.  Older OPs need  decisions
        about their eligibility for reregistration under
        FIFRA. OPs with residue limits in food (tolerances) and other non-occupational exposures also must
        be reassessed to make sure they meet the new FQPA safety standard.
      The OP Pilot Public Participation Process

          The organophosphates are a group of
    related pesticides that affect the functioning of the
    nervous system. They are among EPA's highest
    priority for review under the Food Quality Protection
          EPA is encouraging the public to
    participate in the review of the OP pesticides.
    Through a six-phased pilot public participation
    process, the Agency is releasing for review and
    comment its preliminary and revised scientific risk
    assessments for individual OPs. (Please contact
    the OP Docket, telephone 703-305-5805, or see
    EPA's web site,
          EPA is exchanging information with
    stakeholders and the public about the OPs, their
    uses, and risks through Technical Briefings,
    stakeholder meetings, and other fora. USDA is
    coordinating input from growers and other OP
    pesticide  users.
          Based on current information from
    interested stakeholders and the public, EPA is
    making risk management decisions for individual
    OP pesticides, and will make final decisions
    through a cumulative OP assessment.
               The phostebupirim interim decision was made through the OP pilot public participation process,
        which increases transparency and maximizes stakeholder involvement in EPA's development of risk

assessments and risk management decisions. EPA worked with affected parties to reach the decisions
presented in this interim decision document, which concludes the OP pilot process for phostebupirim.
       Phostebupirim is an organophosphate insecticide registered for use on field corn, seed corn,
       sweet corn, and popcorn for the control of corn rootworms, wireworms, cutworms, seed corn
       maggots, seedcorn beetles and white grubs.

       Annual domestic use is estimated to be approximately 270,000 pounds of active ingredient per
•      In addition to the technical, there are three end-use formulations: two 2.1% granular
       formulations (clay-based and cellulose-based) and a 4.67% granular formulation for use only
       with a SmartBox® applicator system.

Health Effects

•      Phostebupirim can cause cholinesterase inhibition in humans;  that is, it can overstimulate the
       nervous system causing nausea, dizziness, confusion, and at very high exposures (e.g., accidents
       or major spills), respiratory paralysis and death.


•      Dietary risks from food and drinking water are not of concern.

•      Handler risks under the current risk assessment are of concern without appropriate PPE and
       engineering  controls during the loading and application processes.

•      EPA did not quantitatively assess the risks to post application workers. Since phostebupirim is
       mainly incorporated into the soil at planting, minimal post application exposure is anticipated.

Risk Mitigation

•      The Agency is recommending label changes which are intended to mitigate potential
       occupational risk from occupational exposure to phostebupirim products. The changes include
       a dust/mist respirator for loaders of the 2.1% granular clay-based formulation, emergency PPE
       requirements, establishment of an REI if re-entry activities disturb the soil surface, and the
       addition of a double notification statement.

       The registrant will need to submit an exposure or dust comparison study to confirm that the
       cellulose-based Biodac formulation is sufficiently less dusty than the clay-based formulation.
       This study should be submitted to EPA by April 1, 2001.

       The registrant is conducting a 21-day rat dermal toxicity study to be submitted by April 1,
       2001, which will be used to refine both the short and intermediate-term occupational risk
       assessments. The Agency believes that this data will provide a more appropriate endpoint for
       assessing dermal exposure risks than the studies currently available, and will demonstrate that
       occupational risks are adequately mitigated with the measures presently recommended.  The
       Agency plans to recommend any appropriate additional occupational risk mitigation measures
       before the conditional registration is set to expire on  July 5, 2001, should such measures
       remain necessary following refinement of the risk assessment.
Next Steps
       Numerous opportunities for public comment were offered as this decision was being
       developed.  The  Interim Tolerance Reassessment Evaluation and Risk Management Decision
       for phostebupirim is therefore issued in final (see www.epa.        cides/op). without a formal
       public comment period.  The docket remains open, however, and any comments submitted in
       the future will be placed in this public docket.

       To effect the label amendments as quickly as possible, time frames for making the changes
       required by the Interim Tolerance Reassessment Evaluation and Risk Management Decision
       document are shorter than those in a usual RED.  The Agency is asking that all labels be
       amended to include the above mitigation and submitted to the Agency within 90 days after
       issuance of this document.

       When the cumulative risk assessment for all organophosphate pesticides is completed, EPA will
       issue its final tolerance reassessment decision for phostebupirim and may require further risk
       mitigation measures.