United States
Environmental Protection
Agency
Prevention, Pesticides
and Toxic Substances
(75O8C)
EPA 738-F-02-004
June 2OO2
Ethoprop Facts
EPA has assessed the risks posed by the use of the active ingredient ethoprop, and
reached an Interim Reregistration Eligibility Decision (IRED) for this organophosphate (OP)
pesticide. Provided that risk mitigation measures are adopted, EPA has made the determination
that ethoprop fits into its own "risk cup"-- that is, its individual and aggregate risks are within
acceptable levels, provided the stipulated risk mitigation measures are implemented. Thus,
ethoprop products, except for the liquid formulation, are eligible for reregistration, pending
consideration of the cumulative risk for all OPs. The Agency will make a reregistration
eligibility decision for the liquid formulation at a later time, provided certain conditions are
fulfilled.
Ethoprop residues in food do not pose risk
concerns. Although there is concern for drinking water
risks based on estimates from screening-level water
modeling, the Agency believes actual drinking water
exposures are much lower and are not of concern. With
the implementation of a variety of risk reduction
measures, ethoprop's worker and ecological risks will be
substantially reduced. Also, ethoprop has no residential
uses, and its use on golf course turf has been voluntarily
canceled.
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 the Federal Insecticide, Fungicide,
and Rodenticide Act (FIFRA). OPs with residues in
food, drinking water, and other non-occupational
exposures also must be reassessed to make sure they
meet the new Food Quality Protection Act (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 interim risk management decisions for
individual OP pesticides, and will make final
decisions once the cumulative risks for all the OPs
are considered.
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EPA's next step under FQPA is to consider the cumulative risks and risk management
decision encompassing all the OP pesticides, which share a common mechanism of toxicity. The
interim decision on ethoprop cannot be finalized until the cumulative risks for all the OPs are
considered. Further risk mitigation may be warranted at that time.
The ethoprop 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 decisions in this interim decision document, which concludes the OP
pilot process for ethoprop.
Uses
An insecticide and nematicide, ethoprop is used to control wireworms and nematodes in
potatoes, sugar cane, sweet potatoes, and tobacco, with lesser usage on com (field and
sweet), beans (lima and snap), cucumbers, and cabbage. In addition, it is used to treat
pineapples, bananas, and plantains, as well as field-grown ornamentals and non-bearing
citrus trees.
According to Agency estimates, annual domestic use was approximately 700,000 pounds
of active ingredient per year from 1987 through 1996. Based on usage data from the
technical registrant for 1998 through 2000, about 1 million pounds of active ingredient
per year is used nationally. The more recent data indicate that roughly 60% of the
ethoprop applied is used on potatoes, with sugar cane and sweet potatoes accounting for
the next higher usages.
Health Effects
Ethoprop 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 exposures from eating food crops treated with ethoprop is not of concern to the
Agency for the entire U.S. population or for any population subgroup, including infants
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and children. Dietary exposure from drinking water is of concern to the Agency, based
on estimates from screening-level modeling for both surface and ground water sources.
• EPA has risk concerns for workers who load and apply ethoprop, both the granular and
liquid formulations. For the granular formulations, the worker risk concerns are driven
by the amount of dust and the potential for inhalation exposure. For the liquid
formulation, the risk driver is the potential for dermal exposure. To address this concern,
the registrant is conducting a worker biomonitoring study to provide highly-refined,
product-specific data. A reregistration eligibility decision will not be made on the liquid
formulation until these studies are completed.
• Ethoprop presents risks to non-target terrestrial wildlife species, including birds,
mammals, and bees. In addition, it presents high risks to aquatic organisms, both fish and
invertebrates.
Benefits
The benefits of ethoprop use on potatoes are estimated to be important, especially for the
liquid formulation in areas with low rainfall, due to its availability to be tank-mixed and co-
applied with liquid soil fumigants, and its efficacy to control nematodes and wireworms. There
are benefits for the use of the liquid, as well as granular formulations, for other crops as well,
such as sugar cane, sweet potatoes, bananas, plantains, and pineapples.
Risk Mitigation
Dietary Risk
No mitigation is necessary at this time for any dietary (food) exposure to ethoprop. The
acute and chronic dietary (food) risks from ethoprop do not pose concerns to the Agency.
Drinking water risk assessments are based on screening-level modeling estimates. The
Agency believes actual drinking water exposures are much lower and are not of concern. To
provide actual exposure data to demonstrate that drinking water risks are not of concern, the
registrant will conduct drinking water monitoring of both surface and ground water sources.
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Occupational Risk
In order to mitigate occupational risks, the following risk mitigation measures are
necessary:
• treatment of golf courses is being voluntarily cancelled;
• restrict the maximum number of applications for all uses to one application per year,
except for use on bananas, plantains, and pineapples; and
• reduce the maximum application rates (for tobacco from 12 pounds of active ingredient
per acre (Ib ai/A) to 6 Ib ai/A, for potatoes to treat nematodes east of the Mississippi
River from 12 Ib ai/A to 9 Ib ai/A, for ornamentals from 6 Ib ai/A to 3 Ib ai/A, and for
pineapples from 12 Ib ai/A to 6 Ib ai/A).
Specifically for the granular formulations, the following worker risk mitigation measures
are necessary:
• the 10G formulation is voluntarily cancelled;
• the 15G formulation will be manufactured with an inert ingredient having lower dust
content, to mitigate risks associated with inhalation exposures;
• the 20G formulation will now specify use only on sugar cane, and will be packaged
solely in closed transfer containers;
• both of the remaining granular formulations are to be applied to agricultural crops only
with enclosed cab equipment;
• the following applications will be prohibited:
• all aerial applications;
• slit treatment;
• push-type spreaders;
• applications to peanuts;
• broadcast applications to sweet potatoes; and
• all hand applications, including direct hand-held equipment, such as spoons.
Although the Agency is not making a reregistration eligibility decision concerning the
liquid formulation at this time, in the interim, the following risk mitigation measures are
necessary for workers handling the liquid formulation:
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• prohibit applications with: liquid low-pressure handwand sprayers; liquid backpack
sprayers; liquids with a sprinkler can; mixing/loading/applying liquid concentrate by a
handheld measuring container; and hand-dipping of citrus seedlings in liquids;
• prohibit use on: snap beans; lima beans; field com; sweet com; peanuts; sugar cane; and
citrus seedlings; and
• prohibit broadcast applications to cabbage and sweet potatoes.
Ecological Risk
To mitigate ecological risks, the following mitigation measures are necessary:
• all applications of ethoprop must be incorporated into the soil, either by mechanical
means immediately after applications with ground equipment, or by water incorporation;
• the liquid formulation label will specify no-spray zone buffer strips for the protection of
surface waters (including within 140 feet of inland freshwater habitats and along the
Atlantic seaboard, within 800 feet of brackish water habitats); and
• various risk mitigation measures described above will also address ecological concerns,
including:
• restricting the maximum number of applications;
• canceling certain uses;
• reducing maximum application rates; and,
• canceling broadcast applications for some uses.
Next Steps
• There is no additional comment period for the ethoprop IRED, which is in its final form.
The registrant and stakeholders have commented on the risk assessments and the
proposed risk mitigation measures. You can find more information about the Agency's
public participation process for the OPs at www.epa.gov/pesticides/op. For documents
specific to ethoprop, go to www.epa.gov/pesticides/reregistration/status.htm.
• EPA will revoke 9 tolerances for ethoprop as part of the IRED. When the cumulative
risks are considered for the OP pesticides, the Agency will issue its final tolerance
reassessment decision for ethoprop and may request further risk mitigation measures. At
that time, EPA will raise and/or establish new tolerances.
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