Document ID: EPA-HQ-OPP-2004-0032-0031
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2006-06-28T04:00Z

EPA 738-F-06-010

	IRED Fact Sheet for Formetanate HCl

	

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
HCl) and reached an interim Reregistration Eligibility Decision (IRED)
for this N-methyl carbamate pesticide.  Provided that the risk
mitigation measures are adopted, formetanate HCl’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 HCl 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 HCl products. Registered
products containing formetanate HCl are intended for application on tree
fruit and alfalfa grown for seed to control lygus bugs, mites, stink
bugs, and thrips.

Currently, formetanate HCl is only available as a wettable powder
formulation sold in water soluble bags which are considered to be
engineering controls.  Formetanate HCl can be applied with aerial or
ground equipment, such as groundboom sprayers and airblast sprayers. 
Formetanate HCl is labeled for use on tree fruits at 1.15 lb a.i. /A and
for alfalfa grown for seed at a maximum of 0.92 lb a.i. /A.

Health Effects

Formetanate HCl 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 HCl 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 HCl in rats (decreased body weight) and dogs (excessive
salivation, wheezing, labored breathing, trembling, vomiting ,coughing,
and abnormal quietness) are consistent with cholinesterase inhibition.

Formetanate HCl 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 HCl 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 HCl 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 HCl is moderately toxic.  No acute data for
estuarine/marine fish or chronic data for invertebrates were available.

Formetanate HCl 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 HCl can potentially cause
reproductive concerns in birds and cholinesterase inhibition in small
mammals.

There are no indications that formetanate HCl is phytotoxic.  Data
indicate that formetanate HCl is practically nontoxic to bees on an
acute contact basis.  

Risks

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
HCl 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 HCl.  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 HCl.  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. 

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 HCl 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 HCl 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 HCl
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 HCl.  EPA
believes these data will confirm the conclusion that no mitigation is
appropriate for the mixer/loader scenario for aerial applications to
alfalfa. 

●	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

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萏֠萑褐葞֠葠褐摧旱zጀcept 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 HCl 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 HCl IRED, or reregistration of individual products
containing formetanate HCl], 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. 

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