United States
Environmental Protection
Agency
Prevention, Pesticides
and Toxic Substances
(7508C)
EPA738-F-00-015
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
Act.
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
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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.
Uses
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
year.
Formulations
• 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.
Risks
• 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.
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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.
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