United States Prevention, Pesticides EPA 73S-.1.0 tf&Olf
Environmental Protection and Toxic Substances May 2004 /
Agency (7508W)
I.R.E.D. FACTS
Diazinon
Pesticide EPA has assessed the risks of diazinon and reached an Interim
Reregistration Reregistration Registration Eligibility Decision (IRED) for this
organophosphate (OP) pesticide. Without mitigation, diazinon poses
unacceptable risks to agricultural workers and to birds and other wildlife
species. To increase protection for workers, birds, and the environment, the
Agency's decision includes provisions to phase out and cancel certain
agricultural crop uses, the granular formulation, and aerial applications;
reduce the amount and frequency of use; and employ engineering controls
and other protective measures. These changes in diazinon use were
developed through discussions with the technical registrants and were
based on extensive stakeholder input
Diazinon has been one of the most widely used insecticides in the U.S.
for household as well as agricultural pest control. A December 2000 agreement
with the technical registrants phased out and cancelled all indoor and outdoor
residential uses in order to reduce risks to children and others.
Diazinon residues in food and drinking water resulting from agricultural
uses do not pose human dietary risks of concern. While residues attributed to
agricultural and residential uses have been detected frequently in surface
waters, previous mitigation measures for residential products should result in
less frequent detections in water. Without further mitigation limiting children's
and others' exposure through food and drinking water, diazinon fits into its own
"risk cup." Even with the recommended mitigation measures, diazinon's worker
and ecological risks still will be above levels of concern, but these risks are
offset by strong benefits of diazinon use in fruit and vegetable productioiL
EPA's next step is to consider the cumulative effects of the OP
pesticides, which share a common mechanism of toxicity. The interim decision
on diazinon will not be final until the Agency completes a cumulative evaluation
of the OPs. Further risk mitigation may be warranted at that time.
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Use Profile
EPA is reviewing the OP pesticides to determine whether they meet
current health and safety standards. Older OPs require decisions about their
eligibility for reregistration under FIFRA. OPs with food, drinking water,
residential, and any other non-occupational exposures must be reassessed to
make sure they meet the new FFDCA safety standard, brought about by the
Food Quality Protection Act of 1996 (FQPA).
The IRED concludes EPA's review of diazinon through the OP pilot
public participation process, which increases transparency and maximizes
stakeholder involvement in the Agency s development of risk assessments and
risk management decisions. EPA worked extensively with affected parties to
reach the decisions presented in the Diazinon IRED. During the past several
years, the Agency has exchanged information on diazinoris uses, risks, and
benefits with USDA, other federal and state agencies, registrants, users, the
environmental community, concerned citizens, and others. This significant input
from stakeholders and interested parties helped EPA reach a decision mat
diazinon is eligible for reregistration and meets the FQPA safety standard.
Diazinon is registered to control foliage and soil insects and pests of
many fruit, nut, vegetable, and ornamental crops. Diazinon also is used in cattle
eartags. All residential uses have been cancelled.
Approximately 4 million pounds of the active ingredient diazinon are
used annually on agricultural sites. Use is highest on almonds and stone fruits.
Hearth
Effects
Risks
Residential Risk
Mitigation
Diazinon can cause cholinesterase inhibition in humans; that is, it
can overstimulate the nervous system causing nausea, dizziness,
contusion, and at very high exposures (e.g. accidents or major spills)
respiratory paralysis and death.
• Dietary risks from exposure to diazinon residues in food and drinking water
do not exceed the Agency's level of concern.
• Occupational exposure to diazinon is of concern to EPA for handlers and
applicators of diazinon as well as to workers entering fields after applications.
• EPA has identified ecological risks of concern from diazinon use, particularly
to birds, mammals, bees, fish, and aquatic invertebrates.
Known as Spectracide and other trade names, diazinon was
one of the most widely used insecticides in the U.S. for household lawn and
garden pest control (up to 70% of the 13 million pounds used each year),
indoor residential crack and crevice treatments and pet collars (up to 5% of all
use), and agricultural pest control (about 30% of all use). To reduce risks to
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children and others, the December 2000 agreement phased out and cancelled
all residential uses. All indoor residential use product registrations were
cancelled and retail sale of these products ended as of December 31,2002. All
outdoor residential use product registrations must be cancelled and retail sale
must end by December 31,2004. After that time, a buy-back program will
help remove remaining outdoor diazinon residential use products from the
market and prevent further sale.
Agricultural and To mitigate risks to agricultural workers, birds and other wildlife, the
Ecological Risk following mitigation measures are required by the Diazinon IRED. All
Mitigation deletions and cancellations will be phased in during the next 2 to 5 years.
• Cancellation of all granular registrations, except for use on lettuce in
California and Arizona and two current Section 24(c) registrations held by
Washington and Oregon for control of the cranberry girdler.
• Deletion of aerial application for all uses, except for one application per
crop for lettuce.
• Deletion of foliar application on all vegetable crops, except for
treatment of leafhopper on honeydew melons in California and one application
per crop for lettuce.
• Application rate reduction for ornamentals and lettuce.
• Establishment of crop specific REls. REIs of 2 days to 18 days will be
established for all crops.
• Cancellation of ail seed treatment uses.
• Require engineering controls for all uses. All application equipment
must use lock and load engineering controls. All wettable powder formulations
must be packaged in water soluble bags. Closed cabs are required all ground
equipment, except for applications to apples.
• Reduce the number of applications of diazinon per growing season.
For most uses, only one application per growing season will be allowed Crops
with dormant season and in season uses (e.g., stone fruits) will have one
application per season, for a total of two applications per year. Other
exceptions are noted in the Labeling Summary Table in Chapter 5 of the IRED.
• Cancellation of the following uses:
Section 3 registrations: Chinese broccoli, Chinese cabbage, Chinese
mustard, Chinese radish, corn, grapes, hops, mushrooms, sugarbeets,
walnuts, and watercress.
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Benefits Analysis
Next Steps
Section 24(c) registrations: Control of cranberry girdler for grass
grown for seed (Oregon); dipping of pineapple seed pieces (Hawaii);
drenching around residential fruit trees for control of Mediterranean fruit
fly (California).
Benefits information was required for diazinon based on its risks to
workers and wildlife. Complete benefits assessments, evaluating the economic
and agricultural effects of cancellation of diazinon, were prepared for crops with
over 5% of the crop treated with diazinon. In issuing the Diazinon RED, EPA
is requesting public comment on these uses, including almonds, apricots,
blueberries, broccoli, Brussels sprouts, cabbage, caneberry crop group,
carrots, cauliflower, cherries (sweet), cranberries, hops, lettuce, melons,
nectarines, onions, peaches, pears, plums, prunes, radishes, strawberries, and
tomatoes. The benefits assessments can be found on EPA's website in the
diazinon electronic docket at
http://cascade.epa.gov/RiyhfSlte/dk public home.hfm (OPP Docket #
OPP-2002-025 1) and through the diazinon web page,
The Diazinon IRED was issued for 60 days of public comment through
a September 25, 2002, Federal Register notice. This comment period was
extended in December 2002 for an additional 30 days, closing January 8,
2003. EPA has amended the IRED document in accordance with comments
received The letter to registrants listing amendments is available with the IRED
document.
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