United States
              Environmental Protection
Prevention, Pesticides
and Toxic Substances
September 2001
             Acephate  Facts
       EPA has assessed the risks of acephate and reached an Interim Reregistration Eligibility
Decision (IRED) for this organophosphate (OP) pesticide. Provided that risk mitigation measures are
adopted, acephate fits into its own "risk cup"-- its individual, aggregate risks are within acceptable
levels. Acephate also is eligible for reregistration, pending a full reassessment of the cumulative risk
from all OPs.
       Acephate residues in food and drinking water
do not pose risk concerns, and by reducing exposure
in homes and through residential lawns, acephate fits
into its own "risk cup." EPA made this
determination after the registrants agreed to drop
indoor residential uses and certain turf uses. With
other mitigation measures, acephate's worker and
ecological risks also will be below levels of concern
for reregistration.

       EPA's next step under the Food Quality
Protection Act (FQPA) is to consider risks from
cumulative exposure to all the OP pesticides, which
share a common mechanism of toxicity.  The interim
decision on acephate cannot be considered final until
the cumulative risk has been considered. Further
risk mitigation may be warranted 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 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 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 after the cumulative risk from all OPs
         has been considered.
       The acephate interim decision was made through the OP pilot public participation process, a
process that 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 presented in this interim decision document that concludes the OP pilot process
for acephate.


       Acephate is an organophosphate insecticide currently registered for use on a variety of field,
       fruit, and vegetable crops (e.g., cotton, tobacco, cranberries, mint); in food handling
       establishments; on ornamental plants both in greenhouses and outdoors (e.g., nonbearing fruit
       trees, Christmas trees, and cut flowers); and in and around the home.

      Annual domestic use is approximately 4 to 5 million pounds of active ingredient per year.

Health Effects

       Acephate 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 exposures to acephate from eating food crops treated with acephate are below the
       level of concern for the entire U. S. population, including infants and children. Drinking water
       is not a significant source of acephate exposure. However, people in the U.S. may be exposed
       to amounts of the acephate degradate methamidophos through food and drinking water as a
       result of acephate use. This exposure will be more fully addressed in the methamidophos

       EPA found risks are of concern for homeowners and children entering homes and lawn areas
       treated with acephate (excluding golf courses and spot or mound treatments for ant control).

       For agricultural and turf/Pest Control Operator (PCO) uses of acephate, several
       mixer/loader/applicator risk scenarios currently exceed the Agency's level of concern. In
       addition, there are postapplication risks from the use of acephate in cut flowers.

       Ecological risks are also of concern to the Agency. Acephate and its degradate
       methamidophos are highly toxic to honey bees and beneficial predatory insects on an acute
       contact basis. Acute and chronic risks to birds and chronic risk to mammals are also high.

Risk Mitigation

Dietary Risk

       No mitigation is necessary at this time for any dietary exposure to acephate. The acute and
chronic dietary risks from acephate do not exceed the Agency's level of concern.

       However, the Agency reserves the right to require further acephate mitigation to address risks
from methamidophos residues resulting from acephate uses. Any additional mitigation measures will
be addressed when the methamidophos interim RED is completed.

Occupational Risk

       In order to mitigate occupational risks, the following risk mitigation measures are necessary:

      Formulate all soluble powder formulations into water soluble bags, except for soluble
       powders sold for fire ant, harvester ant, or hopper box seed treatment uses.
      Limit the 1 pound active ingredient per acre (Ib ai/A) cotton aerial application rate to cotton
       grown in California and Arizona; reduce the maximum aerial application rate for cotton to
       0.75 ai/A for all  other areas of the United States.
       Delete aerial application to turf.
       Require enclosed cockpits and mechanical flagging for all aerial applications.
      Reduce maximum sod farm and golf course turf application rates (non-granular formulations)
       to 3 Ib ai/A and 4 Ib ai/A, respectively.
      Reduce maximum application rates for greenhouse floral and foliage plant crops, and outdoor
       floral and ground covers to  1 Ib ai per 100 gallons water (not to exceed 0.75 Ib ai/A for cut
       flowers and 1.0 Ib ai/A for other ornamentals).
       Delete the application of acephate by low pressure handwand to treat trees, shrubs, and
       outdoor flora; for the control of wasps; and for perimeter treatment by PCOs.
       Delete the use of granular formulations to be applied by belly grinder, shaker can, or by hand
       to trees, shrubs, and 12" pots.
      Add personal protective equipment to end use product labels for workers who mix and load,
       and/or apply acephate.

Residential Risk

       In order to mitigate residential postapplication risk, the following risk mitigation measures are

      Delete residential indoor uses.
      Delete all turfgrass uses (except golf course, sod farm, and spot or mound treatment for ant
       Establish a 3 day pre-harvest interval (PHI) for the harvesting of sod.

Ecological Risk

       The Agency has determined that the following mitigation measures are needed to address
ecological risk concerns:

       Establish minimum spray intervals for all agricultural crops of 3 days for application rates up
       to 0.5 Ib ai/A and of 7 days for application rates greater than 0.5 Ib ai/A.
      Require labeling to protect honeybees.
      Require labeling to reduce the potential for spray drift.

       In addition, the measures to reduce occupational and residential risk will also reduce
environmental loading and the potential impact to non-target organisms.

Next Steps

      Numerous opportunities for public comment were offered as this decision was being
       developed.  The acephate IRED therefore is issued in final (see
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       formal public comment period. The docket remains open, however, and any comments
       submitted in the future will be placed in this public docket.

       In addition, further mitigation of acephate uses may be necessary to reduce risks from
       methamidophos residues that result from acephate applications. Once the methamidophos
       IRED is complete, the Agency will determine whether the methamidophos exposure resulting
       from acephate use poses risk concerns.  Any potential further mitigation will be discussed at
       the time the methamidophos interim RED is released.

       When the cumulative risk assessment for all organophosphate pesticides is completed, EPA
       will issue its final tolerance reassessment decision for acephate and may request further risk
       mitigation measures.  The Agency will revoke 3 tolerances and lower 4 tolerances for
       acephate now. Reassessment of 14 tolerances will be made once additional residue data on
       cotton gin byproducts have been reviewed. For all OPs, raising and/or establishing tolerances
       will be considered once a cumulative assessment is completed.