Interim Reregistration Eligibility Decision
(IRED) Fact Sheet for Formetanate
Hydrochloride
EPA 738-F-06-01
Pesticide Reregistration
All pesticides sold or distributed in the United States must be registered by EPA, based on scientific
studies showing that they can be used without posing unreasonable risks to people or the
environment. Because of advances in scientific knowledge, the law requires that pesticides first
registered before November 1, 1984, be reregistered to ensure that they meet today's more stringent
standards.
In evaluating pesticides for reregistration, EPA obtains and reviews a complete set of studies from
pesticide producers that describe the human health and environmental effects of each pesticide. To
implement provisions of the Food Quality Protection Act (FQPA) of 1996, EPA considers the special
sensitivity of infants and children to pesticides, as well as aggregate exposure of the public to
pesticide residues from all sources, and the cumulative effects of pesticides and other compounds with
common mechanisms of toxicity. The Agency develops any mitigation measures or regulatory controls
needed to effectively reduce each pesticide's risks. EPA then reregisters pesticides that meet current
human health and safety standards and can be used without posing unreasonable risks to human
health and the environment.
EPA has assessed the risks of formetanate hydrochloride (formetanate HCI) and reached an interim
Reregistration Eligibility Decision (IRED) for this N-methyl carbamate pesticide. Provided that the risk
mitigation measures are adopted, formetanate HCI's individual aggregate risks will be within
acceptable levels, and the pesticide will be eligible for reregistration once EPA has considered the
cumulative risks from the N-methyl carbamates.
Uses
Formetanate HCI is a miticide/insecticide used on alfalfa (grown for seed), apples, pears, peaches,
nectarines, and assorted citrus crops. There are no residential uses for formetanate HCI products.
Registered products containing formetanate HCI are intended for application on tree fruit and alfalfa
grown for seed to control lygus bugs, mites, stink bugs, and thrips.
Currently, formetanate HCI is only available as a wettable powder formulation sold in water soluble
bags which are considered to be engineering controls. Formetanate HCI can be applied with aerial or
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ground equipment, such as groundboom sprayers and airblast sprayers. Formetanate HCI is labeled
for use on tree fruits at 1.15 Ib a.i. /A and for alfalfa grown for seed at a maximum of 0.92 Ib a.i. /A.
Health Effects
Formetanate HCI has high acute toxicity via the oral route, moderate acute toxicity via the inhalation
route and has low acute toxicity via the dermal route. It is not an eye or skin irritant but is a dermal
sensitizer.
Formetanate HCI is a carbamate pesticide, and its primary mode of toxic action is through
cholinesterase inhibition after single or multiple exposures. The clinical signs following acute and
chronic exposure to formetanate HCI in rats (decreased body weight) and dogs (excessive salivation,
wheezing, labored breathing, trembling, vomiting ,coughing, and abnormal quietness) are consistent
with cholinesterase inhibition.
Formetanate HCI did not result in developmental toxicity in either rats or rabbits or in reproductive
effects in the multi-generation rat reproduction study. There was no indication of increased offspring
susceptibility in these studies.
Formetanate HCI is potentially neurotoxic because of its ability to inhibit cholinesterase. A
Comparative Cholinesterase Assay (CCA) study in rats was submitted to EPA in lieu of a
developmental neurotoxicity study to determine the susceptibility of the young compared to the
adults. The endpoint of rat pup brain cholinesterase inhibition was derived from the CCA study.
Ecological Effects
Available acute toxicity data indicate that formetanate HCI is moderately to slightly toxic to freshwater
fish and highly toxic to freshwater invertebrates on an acute basis. Chronic data for freshwater fish
show that growth and development was the most sensitive endpoint. For estuarine/marine
invertebrates, available acute toxicity data indicate that formetanate HCI is moderately toxic. No
acute data for estuarine/marine fish or chronic data for invertebrates were available.
Formetanate HCI is classified as highly toxic to birds and mammals on an acute basis and slightly toxic
to birds on a subacute basis. Chronic data indicate that use of formetanate HCI can potentially cause
reproductive concerns in birds and cholinesterase inhibition in small mammals.
There are no indications that formetanate HCI is phytotoxic. Data indicate that formetanate HCI is
practically nontoxic to bees on an acute contact basis.
Risks
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Dietary Risk Assessment for Food + Water
Acute Dietary Risk
The resulting acute dietary exposure and risk estimates for food and water exceed EPA's level of
concern for the U.S. population and all reported population subgroups. Most of the estimated acute
exposure from food was determined to result from late season uses of formetanate HCI on apples.
Deletion of the late season apple use results in an acute dietary (food + water) risk within an
acceptable range of the level of concern. Drinking water is the largest contributor to acute dietary
exposure when late season uses are excluded.
Chronic Dietary Risk
Chronic risk estimates are below EPA's level of concern for the U.S. population and all population
subgroups.
Aggregate Risk
There are no residential uses for formetanate HCI. Therefore, when addressing aggregate exposures,
only the dietary pathways of food and drinking water were considered.
Acute aggregate exposure estimates for food and water exceed EPA's level of concern with the
inclusion of late season applications to apples, but are below the level of concern without this use.
Chronic aggregate exposure estimates for food and water are below the Agency's level of concern.
Occupational Risk
Handler Risk
The Agency used a margin of exposure (MOE) approach to assess formetanate HCI. MOEs greater
than 100 are not of concern. No scenarios resulted in MOEs above 100 for single layer personal
protective equipment (PPE); however, after a respirator was added for applicators using groundboom
equipment in alfalfa for seed production, the risk was below EPA's level of concern (MOE=130). Most
scenarios for applicators had MOEs above 100 at maximum PPE (double layer clothing plus gloves and
respirator) except for airblast applications to orchards (MOE=73). Scenarios for mixing and loading for
aerial applications for both orchard crops (MOE=51) and for alfalfa grown for seed (MOE=69) had
risks above the Agency's level of concern even with engineering controls of water soluble bags.
MOEs for flaggers are at an acceptable level with double layer PPE and a respirator. However, EPA has
concerns with requiring additional protective clothing for these workers due to the potential for heat
stress.
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Postapplication Risk
For high-end activities, MOEs were acceptable for re-entry intervals (REI) by day 10 for evergreen
fruit trees (citrus), day 8 for deciduous fruit trees (pome and stone fruits), and day 9 for alfalfa. It
was determined that high exposure activities (hand harvesting) are not appropriate for alfalfa, and
therefore, a 6-day REI is considered appropriate to protect post application workers performing
medium-exposure activities.
Ecological Risks
From the screening level ecological risk assessment, risks to aquatic animals (both freshwater and
estuarine/marine environments) were below the Agency's level of concern. Acute risks to birds are
below the Agency's level of concern from formetanate HCI use. However, the Agency had concerns for
chronic risks to birds. RQs ranged from 2 to 5. EPA also had concerns with acute and chronic risks to
mammals (RQ's were as high as 28). Acute risks to birds are below the Agency's level of concern from
formetanate HCI use. However, the Agency had concerns for chronic risks to birds. RQs ranged from 2
to 5. EPA also had concerns with acute and chronic risks to mammals (RQ's were as high as 28).
Risk Mitigation
The following risk mitigation measures are required for formetanate HCI to address risks of concern.
• To mitigate dietary risks:
» Amend labels to prohibit late season applications to
apples.
• To mitigate occupational risks to handlers:
» Revise labels to prohibit aerial application for orchard
crops.
* Revise labels to require closed cabs for applicators using
airblast sprayers on orchard fruit.
* Revise labels to require closed cabs for human flaggers
for aerial application
* Revise labels by reducing the PPE to a single layer with a
PF5 respirator for applicators using groundboom
equipment for alfalfa for seed.
Although the Agency is concerned with the MOE for the mixing/loading scenario for aerial application
on alfalfa grown for seed, EPA recognizes that the use provides high benefits to the grower
community. In addition, EPA recognizes that the inputs used to calculate the inhalation assessment
were based on conservative assumptions. The Agency is requiring additional data which will provide a
more refined estimate of the inhalation risks for workers handling formetanate HCI. EPA believes
these data will confirm the conclusion that no mitigation is appropriate for the mixer/loader scenario
for aerial applications to alfalfa.
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To mitigate occupational risks to post-application agricultural
workers:
Revise labels to require a 10 day REI for citrus, an 8 day
REI for pome fruit and stone fruits, and a 6 day REI for
alfalfa.
To mitigate ecological risk:
No ecological specific mitigation is required. Some of
the human health mitigation will result in lower non-
target organism exposures.
Regulatory Conclusion
EPA has determined that all supported uses of formetanate HCI are eligible for reregistration (except
for late season uses on apples) provided that registrants implement risk mitigation measures
described in the IRED and that cumulative risks of the N-methyl carbamates do not exceed EPA's level
of concern.
For More Information
Electronic copies of the formetanate HCI IRED and all supporting documents are available in Docket
#EPA-HQ-OPP-2004-0032 at http://www.regulations.gov.
For more information about EPA's pesticide reregistration program, the formetanate HCI IRED, or
reregistration of individual products containing formetanate HCI, please contact the Special Review
and Reregistration Division (7508C), Office of Pesticide Programs, US EPA, Washington, DC 20460,
telephone 703-308-8000.
For information about the health effects of pesticides, or for assistance in recognizing and managing
pesticide poisoning symptoms, please contact the National Pesticide Information Center (NPIC). Call
toll-free 1-800-858-7378, from 6:30 am to 4:30 am Pacific Time, or 9:30 am to 7:30 pm Eastern
Standard Time, seven days a week. The NPIC internet address is http://npic.orst.edu. <-•!', "' i -i
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