United States
Environmental Protection
Agency
Prevention, Pesticides
and Toxic Substances
(7508C)
EPA738-F-00-005
July 2000
Profenofos Facts
EPA has assessed the risks of profenofos and reached an Interim Reregistation Eligibility
Decision (IRED) for this organophosphate (OP) pesticide. With the risk mitigation measures required,
profenofos fits into its own "risk cup"-- its individual, aggregate risks are within acceptable levels.
Profenofos also is eligible for reregistation, pending a full reassessment of the cumulative risk from all
OPs.
Used only on cotton crops, profenofos
residues in food and drinking water do not pose
risk concerns. Profenofos has no residential
uses, and fits into its own "risk cup." With
required mitigation measures, profenofos'
worker and ecological risks are believed to be
significantly reduced. Additional data have
been required to confirm this expectation.
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 profenofos
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. OPs need decisions about
their eligibility for reregistation under FIFRA.
Additional OPs with residues in food, drinking water, and other non-occupational exposures also must
be reassessed to make sure they meet the new FQPA safety standard.
The profenofos 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 extensively with affected parties to reach
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, www.epa.gov/pesticides/op .)
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 interim risk management decisions for
individual OP pesticides, and will make final
decisions through a cumulative OP assessment.
-------
the decisions presented in this interim decision document, which concludes the OP pilot process for
profenofos.
Uses
An insecticide/miticide, profenofos is a restricted use pesticide used solely on cotton, to control
the tobacco budworm, cotton bollworm, armyworm, cotton aphid, whiteflies, spider mites,
plant bugs, and fleahoppers. An estimated 85% of all profenofos is used to control
lepidopteran species (the worm complex) at varying rates. About 30% of this use is at the
maximum label rate of one pound active ingredient per acre.
• Approximately 775,000 pounds of active ingredient are applied to cotton crops each year.
There are no residential uses of profenofos.
Health Effects
Profenofos 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 low for all segments of the population, including
children.
The current occupational risk assessment indicates risk concerns for aerial mixers/loaders and
aerial applicators (with closed mixing/loading systems that are not now required, safety margins
are estimated to be less than 50 - generally, margins less than 100 are of concern to the
Agency).
However, the Agency believes the results of a confirmatory worker exposure study will
demonstrate that required mitigation has effectively reduced exposure and risk to a level that is
not of concern to the Agency. For applicators and mixer/loaders using ground application
equipment, safety margins are over 100 when the use of closed mixing/loading systems and
enclosed tractor cabs are assumed. Risks to workers who enter fields shortly after treatment
also are of concern if personal protective equipment is not used.
Acute risks are of concern for fish. Large-scale fish kills can occur when profenofos is used in
accordance with current labeling. Thirteen such fish kills occurred in Louisiana and Mississippi
during 1994-1996.
-------
Risk Mitigation
To mitigate risks to handlers and workers:
Reduce the maximum application rate to 0.75 pounds of active ingredient per acre;
Allow the higher rate (1 pound active ingredient per acre) only on lepidopteran pests up
to twice per season;
• Require closed mixing/loading systems and enclosed cockpits and cabs;
Prohibit pilots from mixing and loading on the same day as application;
Reduce the seasonal application rate from 6 to 5 pounds active ingredient per acre per
season.
• Require a notice on the label to inform certified crop advisors of the need to provide the
proper level of protective clothing and equipment for workers reentering treated fields.
To mitigate ecological risks:
Require a 300 foot buffer zone around bodies of water for aerial applications;
Require a 100 foot buffer zone around bodies of water for groundboom applications.
• The reduced application rates discussed above should also reduce ecological risks.
Next Steps
• Numerous opportunities for public comment were offered as this decision was being
developed. The profenofos IRED therefore is issued in final (see www.epa.gov/REDs/ or
www.epa.gov/pesticides/opl 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 risk mitigation as quickly as possible, time frames for making the changes required by
the Profenofos IRED are shorter than those in a usual RED. The Agency is requiring that all
labels must be amended to include the above mitigation and submitted to the Agency within 90
days after issuance of this IRED.
The registrant has agreed to study the effectiveness of using the closed loading system required
to reduce exposure to mixer/loaders and applicators. The results of the new exposure study is
due by the year 2001.
When the cumulative risk assessment for all organophosphate pesticides is completed, EPA will
issue its final tolerance reassessment decision for profenofos and may require further risk
mitigation measures. Similarly, the Agency may reconsider any part of this interim decision
based on new information which may come to the Agency's attention. The Agency will revoke
nine tolerances because there are no registered uses and amend one tolerance. For all OPs,
raising and/or establishing tolerances will be considered once a cumulative assessment is
completed.
------- |