Notice of Filing a Pesticide Petition to Establish a Tolerance
for a Certain Pesticide Chemical in or on Food
Note: EPA no longer updates this information, but it may be useful as a reference or resource.
[Federal Register: April 18, 2001 (Volume 66, Number 75)]
[Notices]
[Page 19935-19939]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr18ap01-58]
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ENVIRONMENTAL PROTECTION AGENCY
[PF-1016; FRL-6777-4]
Notice of Filing a Pesticide Petition to Establish a Tolerance
for a Certain Pesticide Chemical in or on Food
AGENCY: Environmental Protection Agency (EPA).
ACTION: Notice.
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SUMMARY: This notice announces the initial filing of a pesticide
petition proposing the establishment of regulations for residues of a
certain pesticide chemical in or on various food commodities.
DATES: Comments, identified by docket control number PF-1016, must be
received on or before May 18, 2001.
ADDRESSES: Comments may be submitted by mail, electronically, or in
person. Please follow the detailed instructions for each method as
provided in Unit I.C. of the SUPPLEMENTARY INFORMATION. To ensure
proper receipt by EPA, it is imperative that you identify docket
control number PF-1016 in the subject line on the first page of your
response.
FOR FURTHER INFORMATION CONTACT: By mail: Suku Oonnithan, Registration
Division (7505C), Office of Pesticide Programs, Environmental
Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460;
telephone number: (703) 605-0368; e-mail address:
oonnithan.suku@epa.gov.
SUPPLEMENTARY INFORMATION:
I. General Information
A. Does this Action Apply to Me?
You may be affected by this action if you are an agricultural
producer, food manufacturer or pesticide manufacturer. Potentially
affected categories and entities may include, but are not limited to:
------------------------------------------------------------------------
Examples of
Categories NAICS codes potentially
affected entities
------------------------------------------------------------------------
Industry 111 Crop production
112 Animal production
311 Food manufacturing
32532 Pesticide
manufacturing
------------------------------------------------------------------------
This listing is not intended to be exhaustive, but rather provides
a guide for readers regarding entities likely to be affected by this
action. Other types of entities not listed in the table could also be
affected. The North American Industrial Classification System (NAICS)
codes have been provided to assist you and others in determining
whether or not this action might apply to certain entities. If you have
questions regarding the applicability of this action to a particular
entity, consult the person listed under FOR FURTHER INFORMATION
CONTACT.
B. How Can I Get Additional Information, Including Copies of this
Document and Other Related Documents?
1. Electronically. You may obtain electronic copies of this
document, and certain other related documents that might be available
electronically, from the EPA Internet Home Page at http://www.epa.gov/.
To access this document, on the Home Page select ``Laws and
Regulations'' ``Regulation and Proposed Rules'' and then look up the
entry for this document under the ``Federal Register--Environmental
Documents.'' You can also go directly to the Federal Register listings
at http://www.epa.gov/fedrgstr/.
2. In person. The Agency has established an official record for
this action under docket control number PF-1016. The official record
consists of the documents specifically referenced in this action, any
public comments received during an applicable comment period, and other
information related to this action, including any information claimed
as confidential business information (CBI). This official record
includes the documents that are physically located in the docket, as
well as the documents that are referenced in those documents. The
public version of the official record does not include any information
claimed as CBI. The public version of the official record, which
includes printed, paper versions of any electronic comments submitted
during an applicable comment period, is available for inspection in the
Public Information and Records Integrity Branch (PIRIB), Rm. 119,
Crystal Mall #2, 1921 Jefferson Davis Highway, Arlington, VA, from 8:30
a.m. to 4 p.m., Monday through Friday, excluding legal holidays. The
PIRIB telephone number is (703) 305-5805.
C. How and to Whom Do I Submit Comments?
You may submit comments through the mail, in person, or
electronically. To ensure proper receipt by EPA, it is imperative that
you identify docket control number PF-1016 in the subject line on the
first page of your response.
1. By mail. Submit your comments to: Public Information and Records
Integrity Branch (PIRIB), Information Resources and Services Division
(7502C), Office of Pesticide Programs (OPP), Environmental Protection
Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460.
2. In person or by courier. Deliver your comments to: Public
Information and Records Integrity Branch (PIRIB), Information Resources
and Services Division (7502C), Office of Pesticide Programs (OPP),
Environmental Protection Agency, Rm. 119, Crystal Mall #2, 1921
Jefferson Davis Highway, Arlington, VA. The PIRIB is open from 8:30
a.m. to 4 p.m., Monday through Friday, excluding legal holidays. The
PIRIB telephone number is (703) 305-5805.
3. Electronically. You may submit your comments electronically by
e-mail to: opp-docket@epa.gov, or you can submit a computer disk as
described above. Do not submit any information electronically that you
consider to be CBI. Avoid the use of special characters
[[Page 19936]]
and any form of encryption. Electronic submissions will be accepted in
Wordperfect 6.1/8.0 or ASCII file format. All comments in electronic
form must be identified by docket control number PF-1016. Electronic
comments may also be filed online at many Federal Depository Libraries.
D. How Should I Handle CBI That I Want to Submit to the Agency?
Do not submit any information electronically that you consider to
be CBI. You may claim information that you submit to EPA in response to
this document as CBI by marking any part or all of that information as
CBI. Information so marked will not be disclosed except in accordance
with procedures set forth in 40 CFR part 2. In addition to one complete
version of the comment that includes any information claimed as CBI, a
copy of the comment that does not contain the information claimed as
CBI must be submitted for inclusion in the public version of the
official record. Information not marked confidential will be included
in the public version of the official record without prior notice. If
you have any questions about CBI or the procedures for claiming CBI,
please consult the person identified under FOR FURTHER INFORMATION
CONTACT.
E. What Should I Consider as I Prepare My Comments for EPA?
You may find the following suggestions helpful for preparing your
comments:
1. Explain your views as clearly as possible.
2. Describe any assumptions that you used.
3. Provide copies of any technical information and/or data you used
that support your views.
4. If you estimate potential burden or costs, explain how you
arrived at the estimate that you provide.
5. Provide specific examples to illustrate your concerns.
6. Make sure to submit your comments by the deadline in this
notice.
7. To ensure proper receipt by EPA, be sure to identify the docket
control number assigned to this action in the subject line on the first
page of your response. You may also provide the name, date, and Federal
Register citation.
II. What Action is the Agency Taking?
EPA has received a pesticide petition as follows proposing the
establishment and/or amendment of regulations for residues of a certain
pesticide chemical in or on various food commodities under section 408
of the Federal Food, Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 346a.
EPA has determined that this petition contains data or information
regarding the elements set forth in section 408(d)(2); however, EPA has
not fully evaluated the sufficiency of the submitted data at this time
or whether the data support granting of the petition. Additional data
may be needed before EPA rules on the petition.
List of Subjects
Environmental protection, Agricultural commodities, Feed additives,
Food additives, Pesticides and pests, Reporting and recordkeeping
requirements.
Dated: April 5, 2001.
James Jones,
Director, Registration Division, Office of Pesticide Programs.
Summary of Petition
The petitioner summary of pesticide petition is printed below as
required by section 408(d)(3) of the FFDCA. The summary of the petition
was prepared by the petitioner and represents the view of the
petitioner. EPA is publishing the petition summary verbatim without
editing it in any way. The petition summary announces the availability
of a description of the analytical methods available to EPA for the
detection and measurement of the pesticide chemical residues or an
explanation of why no such method is needed.
Uniroyal Chemical Company
PP 0F6108
EPA has received a pesticide petition (PP 0F6108) from Uniroyal
Chemical Company, Benson Road, Middlebury, CT 06749 proposing, pursuant
to section 408(d) of the FFDCA, 21 U.S.C. 346a(d), to amend 40 CFR part
180 by establishing a tolerance for residues of bifenazate, hydrazine
carboxylic acid, 2-(4-methoxy-[1,1-biphenyl]-3-yl)-1- methylethyl ester
in or on the raw agricultural commodities (RACs) apple, wet pomace at
1.2 parts per million (ppm); cotton at 0.5 ppm; cotton, gin byproducts
(gin trash) at 20 ppm; fruit, pome, group at 0.75 ppm; fruit, stone,
group (except cherries) at 1.5 ppm; grape at 0.75 ppm; hop at 15 ppm;
and strawberry at 1.5 ppm. As cotton processed commodities fed to
animals may be transferred to milk and edible tissue of ruminants,
tolerances are also proposed for meat at 0.02 ppm and milk at 0.01 ppm.
EPA has determined that the petition contains data or information
regarding the elements set forth in section 408(d)(2) of the FFDCA;
however, EPA has not fully evaluated the sufficiency of the submitted
data at this time or whether the data support granting of the petition.
Additional data may be needed before EPA rules on the petition.
A. Residue Chemistry
1. Plant metabolism. The nature of the residues of bifenazate in
plants is adequately understood based on three crops; apples, cotton,
and citrus. The major residue in all plant metabolism studies is
bifenazate. A minor, but significant metabolite is the oxidation
product of bifenazate, diazene D3598 [(4-methoxybiphenyl-3-
yl)diazenecarboxylic acid isopropyl ester] which was found to inter-
convert readily to and from bifenazate in the plant matrix during the
analytical procedure. Thus, the proposed tolerance expression is for
the parent compound, bifenazate only.
2. Analytical method. Uniroyal has developed analytical methodology
for detecting and measuring residues of bifenazate in or on RACs. A
significant metabolite, D3598 was found to inter-convert readily to and
from bifenazate, the analytical method was designed to convert all
residues of D3598 to the parent compound, bifenazate for analysis. The
method utilizes reversed phase high performance liquid chromatography
(HPLC) to separate the bifenazate from matrix derived interferences,
and oxidative coulometric electro-chemical detection for the
identification and quantification of this analyte. Using this method
the limit of quantitation (LOQ) for bifenazate in cotton, grapes, pome
fruit, stone fruit, and strawberries was 0.01 ppm. For hops the LOQ was
0.05 ppm. The limit of detection (LOD) for this method, which varies
with matrix, is 0.005 ppm.
The analytical method for bifenazate and its major metabolite D3598
in animal samples was designed using the same principles invoked in the
plant method, with minor modifications. However, in animal samples, a
separate aliquot of the extract, was used to determine combined
residues of A1530 (4-hydroxybiphenyl) and its sulfate in milk and meat
samples (these metabolites appeared to be significant in goat
metabolism studies). The extract was subjected to acid hydrolysis to
convert the sulfate conjugate to A1530 (4-hydroxybiphenyl) before it
was quantified by HPLC using fluorescence detectors.
3. Magnitude of residues. An extensive crop residue program has
been conducted for bifenazate in all major growing regions of the
United
[[Page 19937]]
States for the following crops: peaches and plums (representing stone
fruits excluding cherries), apples and pears (representing pome
fruits), strawberries, grapes, cotton, and hops. The results of these
studies can be summarized as follows:
For pome fruit, the maximum expected bifenazate residues
from a single application at 0.5 lbs active ingredient/acre, are 0.58
ppm in apples and 0.30 ppm in pears harvested 7 days after application.
The results of an apple processing study indicate that
bifenazate residues do not concentrate in apple juice, but do
concentrate in wet apple pomace with an average concentration factor
(ACF) of 1.76x.
At a single application rate of 0.5 lbs active ingredient/
acre, the maximum expected bifenazate residues in stone fruit harvested
3 days after application are 1.45 ppm in peaches and 0.15 ppm in plums.
The results of a plum processing study indicate that
bifenazate does not concentrate in prunes.
Following a single application to grapes at 0.5 lbs active
ingredient/acre, the maximum bifenazate residues in fruit harvested 14
days after application is 0.62 ppm. The results of a grape processing
study indicate that bifenazate residues do not concentrate in juice,
but do concentrate in raisins with an ACF of 1.23x, a value well below
the maximum theoretical concentration factor for this commodity.
The maximum bifenazate residue in strawberries harvested 1
day following the last of two treatments at 0.5 lbs active ingredient/
acre/treatment, with treatments separated by 21 days (annual plants) or
45 days (ever bearing plants) is 1.1 ppm.
The maximum expected bifenazate residues in cottonseed and
cotton gin trash from a single treatment at 0.75 lbs active ingredient/
acre applied 60 days before harvest are 0.31 ppm and 18.4 ppm,
respectively. Bifenazate residues do not concentrate in the hulls,
meal, or oil from the processing of cottonseed.
Following a single application to hop plants at a rate of
0.75 lbs active ingredient/acre, the maximum bifenazate residues in
green hops harvested 14 days after application is 11 ppm.
These field trial data are adequate to support proposed tolerances
of 1.5 ppm for stone fruit (excluding cherries), 0.75 ppm; for pome
fruit, 1.2 ppm; for wet apple pomace, 0.75 ppm; for grapes and raisins,
1.5 ppm; for strawberries, 0.5 ppm; for cottonseed, 20 ppm; for cotton
gin trash, and 20 ppm; for hops.
B. Toxicological Profile
1. Acute toxicity. Bifenazate technical has low acute oral, dermal,
and inhalation toxicity in laboratory animals. The oral LD50
in the rat and mouse and the dermal LD50 in the rat were all
>5,000 milligrams/kilograms (mg/kg). The inhalation LC50 in
the rat was >4.4 milligrams/Liter (mg/L) for the technical product. In
eye and dermal irritation studies, bifenazate technical was not an
irritant to eyes or skin irritation and was not a skin sensitizer.
2. Genotoxicity. Bifenazate was evaluated and found to be negative
in the Ames reverse mutation, mouse lymphoma, chinese hampster ovary
(CHO) chromosome aberration and mouse micronucleus assays.
3. Reproductive and developmental toxicity--i. Rabbit teratology
study. Bifenazate did not produce developmental toxicity in rabbits.
Bifenazate technical was administered by oral gavage to pregnant New
Zealand white rabbits at dosage levels of 10, 50, and 200 mg/kg/day. No
test article related effects were seen at any dose level. The no
observed adverse effect level (NOAEL) for maternal and developmental
toxicity was greater than 200 mg/kg/day. A range-finding study
conducted at dosage levels of 125, 250, 500, 750, and 1,000 mg/kg/day
had previously demonstrated maternal mortality at dosage levels of 750
and 1,000 mg/kg/day and abortions at dosage levels of 250 mg/kg/day and
greater.
ii. Rat teratology study. Bifenazate did not produce developmental
toxicity in rats. Bifenazate Technical was administered by oral gavage
to pregnant Sprague Dawley CD rats at dosage levels of 10, 100, and 500
mg/kg/day. A reduction in maternal body weight (bwt) gain was seen at
dosage levels of 100 and 500 mg/kg/day. Clinical observations at 500
mg/kg/day included red material/staining on body surfaces, pale
extremities and brown discharge. No developmental or teratogenic
effects were observed at any dosage level. The NOAEL for maternal
toxicity was 10 mg/kg/day and the NOAEL for developmental toxicity was
greater than 500 mg/kg/day.
iii. Rat reproduction study. Bifenazate showed no effects on
reproduction in a two-generation rat study. Bifenazate technical was
fed to two-generations of male and female Sprague Dawley CD rats at
dietary concentrations of 20, 80, and 200 ppm. At a dosage level of 200
ppm there was a reduction in body weight gain in F0 males
and females. Food consumption was unaffected. There was reduction in
body weight gain in F1 females at all dosage levels and in
F1 males at 80 and 200 ppm in the absence of effects on food
consumption. Since the 20 ppm F1 males did not have a
significant reduction in body weight gain, this dosage level can be
considered a NOAEL for systemic adult toxicity. The reduction in body
weight gain in the F1 females at 20 ppm would not be
considered biologically significant because no effects were observed on
reproductive parameters or in the F2 litter. The
reproductive and developmental NOAEL was >200 ppm (10 mg/kg/day).
4. Subchronic toxicity--i. Rat feeding study. Bifenazate technical
was fed to male and female Sprague Dawley CD rats for 13 weeks at
dietary concentrations of 40, 200, and 400 ppm. At dosage levels of 200
and 400 ppm there was a reduction in red blood cell count and
hemoglobin. Food intake was reduced for 200 ppm females, and 200 and
400 ppm males. Histopathological effects were seen in the liver,
spleen, and adrenal cortex in males and females at 200 and/or 400 ppm.
The maximum tolerated dose (MTD) was exceeded in females at 200 ppm,
and in males and females at 400 ppm. The NOAEL for subchronic toxicity
in rats was 40 ppm (2 mg/kg/day).
ii. Dog feeding study. Bifenazate technical was fed to male and
female Beagle dogs for 13 weeks at dietary concentrations of 40, 400,
and 1,000 ppm. At dosage levels of 400 and 1,000 ppm, there was a
reduction in red blood cell count, hemoglobin and hematocrit. Liver
weights were increased at 400 and 1,000 ppm and centrilobular
hepatocellular hypertrophy was seen in females at 400 ppm, and males
and females at 1,000 ppm. The NOAEL for subchronic toxicity in dogs was
40 ppm (1 mg/kg/day).
iii. Neurotoxicity. No treatment-related effects were seen on
neuro-behavior in a standard functional observation battery conducted
at weeks 8 and 13 of the 13-week rat feeding study. No overt signs of
anti-cholinergic activity, and no statistically significant effects of
cholinesterase activity were found in rats in a 2-week feeding study at
dose levels up to 400 ppm. Plasma, erythrocyte, and brain
cholinesterase activity were evaluated in male and female rats fed
bifenazate-treated diet at 0, 20, 200, or 400 ppm for 2 weeks. All
animals survived until study termination and effects were only seen on
body weight gain and food consumption. The NOAEL for cholinergic
inhibition was greater than 400 ppm (20 mg/kg/day).
[[Page 19938]]
5. Chronic toxicity--i. Dog chronic feeding study. Bifenazate
technical was fed to male and female Beagle dogs for 1-year at dietary
concentrations of 40, 400, and 1,000 ppm. At dose levels of 400 and
1,000 ppm there was a reduction in food consumption in males and
reduced body weight gain in males and females. There was a reduction in
red blood cell count, hemoglobin and hematocrit and an increase in
bilirubin at 400 and 1,000 ppm. Histopathological effects on bone
marrow, kidney, and liver were also seen at these dose levels. The
NOAEL for chronic toxicity in dogs was 40 ppm (1 mg/kg/day).
ii. Rat chronic feeding/oncogenicity study. Bifenazate was not
oncogenic in rats in a 2-year chronic feeding study. Bifenazate
technical was fed to male and female Sprague Dawley CD rats for 2 years
at dietary concentrations of 20, 80, and 160 in females or 20, 80, and
200 ppm in males. Body weight gain was reduced in males and females at
the high dosage levels. A reduction in red blood cell count and an
increase in splenic pigment were seen in females at 160 ppm, while high
dose males exhibited a reduction in total cholesterol and an increase
in splenic pigment. At a dose level of 80 ppm there was a reduction in
body weight gain, a decrease in red blood cell count and an increase in
splenic pigment in females. There was no increase in tumor incidence in
males or females as a result of bifenazate administration. The NOAEL
for chronic toxicity in rats was 20 ppm (1 mg/kg/day).
iii. Mouse oncogenicity study. Bifenazate was not oncogenic in a
mouse oncogenicity study. Bifenazate Technical was fed to male and
female CD-1 mice for 18 months at dietary concentrations of 10, 100,
and 175 ppm in females and 10, 100, and 225 ppm in males. Body weight
gain was reduced in males and females at the high dose level. A
reduction in red blood cell, total leukocyte and lymphocyte counts was
seen in males at 225 ppm. There was no increase in tumor incidence in
males or females as a result of bifenazate administration.
6. Animal metabolism--i. In rat, bifenazate \14\C-Phenyl hydrazine
carboxylic acid, 2-(4-methoxy-[1,1'-biphenyl]-3-yl)-1-methylethyl ester
was extensively metabolized when it was given orally in two dose
levels: Low (10 mg/kg) and high (1,000 mg/kg). Although 2/3 of the
dosed radioactivity was excreted in the feces, bifenazate depicted a
good degree of absorption as indicated from the level of radioactivity
in the bile. In the bile radioactivity study, about 70% of the C-14 was
collected from the cannulated bile ducts of low dosed rats indicating
an active level of absorption and enterohepatic circulation.
The major metabolites present in feces, urine and bile resulted
from several well known metabolic reactions, including hydrazine
oxidation to diazene (D3598), molecular scission with loss of the
hydrazine carboxylic acid portion of the molecule to yield 4-
methoxybiphenyl (D1989) followed by demethylation to form 4-
hydroxybiphenyl (A1530). Metabolites resulted from aromatic
hydroxylation, and conjugation with glucuronic acid or sulfate were
also identified.
ii. Pharmacokinetic parameters. The maximum plasma concentration
(\C\max, calculated as ppm bifenazate equivalents) was
reached much earlier following the low dose (5-6 h) than the high dose
(18-24 h). Elimination half-lives (t 1/2) were marginally longer at the
high dose (12-16 h) than at the low dose (12-13 h). There were no
obvious and consistent sex differences in the pharmacokinetic
parameters.
7. Metabolite toxicology. In a single dose oral toxicity limit test
in rats, the oral LD50 of the diazene product of bifenazate
(D3598) was estimated to be approximately 5,000 mg/kg. At 2 hours and
at 7 days post-dosing, no effects were seen on erythrocyte
cholinesterase inhibition (ChE) in male or female rats. In addition, no
effect on plasma ChE was seen in males at these time points. An
apparent inhibition of plasma cholinesterase was seen in females at 7
days only. Since this effect was seen only in plasma of females at one
time point, it is most likely a pseudo cholinesterase effect without
biological significance. In a dermal toxicity screen, the
LD50 of the diazene was estimated to be >2,000 mg/kg.
Mutagenicity screens with the D3598 showed it to be weakly positive
in the Salmonella plate incorporation assay (Ames) in TA98 with
activation and negative in the L5178Y mouse lymphoma and mouse
micronucleus assays.
8. Endocrine disruption. There are no known reported adverse
reproductive or developmental effects in domestic animals or wildlife
as a result of exposure to this chemical.
A standard battery of toxicity tests have been conducted on
bifenazate. No effects were seen in the reproduction or teratology
studies to indicate that bifenazate has an effect on the endocrine
system. Bifenazate administration to rats for 90 days at dose levels of
200 and 400 ppm resulted in an increased incidence of vacuolation in
the zona fasciculata of the adrenal cortex in male rats. No effect was
seen at a dose level of 40 ppm (2 mg/kg/day). However, in the chronic
rat feeding study, no effect was seen on the adrenal cortex in male
rats fed 200 ppm for 1-year. Furthermore, fasting glucose levels were
not reduced at any dose level in males or females in either study. The
zona fasciculata is the site of cortisol production and cortisol is
required for gluconogenesis during fasting. The finding that fasting
glucose levels are not affected would suggest that adrenal cortex
functionality is not impaired at any dose level by bifenazate.
C. Aggregate Exposure
Bifenazate is a new miticide proposed for uses on pome fruits,
stone fruits, cotton, strawberries, grapes, and hops. Three WP 50%
formulations of bifenazate are registered for control of mites in
ornamental plants grown and/or maintained in containers, or in the
ground, in greenhouses, and shade houses, nurseries, including
christmas tree, and conifer plantations, landscapes, interiorscapes,
residential areas, public, commercial, industrial institutional areas,
recreational sites, such as campgrounds, golf courses, parks, and
athletic fields, and rights of way and other easements.
1. Dietary exposure. Based on dietary, drinking water, and non-
occupational exposure assessments, there is reasonable certainty of no
harm to the U.S. population, any population subgroup, or infants and
children from short-term or chronic exposure to bifenazate.
i. Food. Dietary exposure was estimated using DEEMs\TM\, field
trial residue data and anticipated percent crop treated. The acute
99.9th percentile dietary exposure to the population
subgroup females 13-50 years old was estimated as 0.002413 mg/kg bwt/
day, with a margin of exposure (MOE) of 82,874. The exposure to the
U.S. population (total) was 0.003247 mg/kg bwt/day (MOE 61,596), and
for infants and children was 0.008480 mg/kg bwt/day (MOE 23584) and
0.006751 mg/kg bwt/day (MOE 29,625), respectively. The chronic dietary
exposure to the U.S. population (total) was estimated as 0.000038 mg/kg
bwt/day, and was 0.4% of the reference (RfD). Exposure to non-nursing
infants, the highest exposed population subgroup, was 0.000132 mg/kg
bwt/day (1.3% of the RfD), and exposure to children was 0.000104 mg/kg
bwt/day (1.0% of the RfD). Dietary exposure from bifenazate is well
within EPA's standard acceptable MOEs and RfDs.
ii. Drinking water. Exposure to bifenazate in drinking water is not
anticipated, and is, in fact, unlikely to
[[Page 19939]]
occur. Bifenazate is not expected to contaminate ground water.
Bifenazate degrades rapidly in water and soil, and is immobile in soil.
There is no established maximum contaminant level for residues of
bifenazate in drinking water, and no health advisory levels for
bifenazate have been established. Using Tier I screening models generic
expected environmental concentration (GENEEC) (surface water) and
screening concentrationin ground water (SCI-GRO) (ground water),
estimated environmental concentration (EEC) of bifenazate EEC was
£2.14 parts per billion (ppb) for surface water, and <0.0001
ppb for ground water. As these values are much lower than the drinking
water levels of concern, exposure to potential residues in drinking
water is expected to be negligible.
2. Non-dietary exposure. Food uses described in this petition are
strictly agricultural and will not add to any existing residential non-
dietary exposure. Such exposure has already been assessed in the
process through which Floramite®, Floramite® GS, and
Floramite® LS (50% WP formulations) were registered for
ornamental uses. Residential exposures from ornamental uses are
expected to be very limited, if any at all, since broad spectrum
insecticides (rather than selective insecticides) are generally used
for residential settings. Quantitative risk estimation calculated MOEs
of 1,400 and 3,100 for homeowners and children, respectively, using
default values in EPA draft SOPs for Residential Exposure Assessment.
Use of product-specific foliar residue decline data would be expected
to lower calculated MOEs. The MOEs, reflecting the limited potential
for exposure from residential uses, were all greater than 1,000, and
well within acceptable limits.
D. Cumulative Effects
The mechanism of action of bifenazate on the mammalian red blood
cell, which is target organ in the species tested, remains to be
elucidated. The lack of information on bifenazate mode of action
precludes an assessment of cumulative effects.
E. Safety Determination
1. U.S. population. Based on the toxicology data base and available
information on anticipated residues, the acute dietary exposure MOE was
>82,000 for females 13-50 years old. This is well above EPA's standard
of acceptable MOE of 100. Chronic dietary exposure to the U.S.
population (total) was 0.4% of the RfD. Exposure to potential residues
in drinking water is expected to be negligible, as drinking water
levels of concern (DWLOC's) are substantially higher than modeled acute
and long-term EEC's. The MOE's from the limited potential for short-
term exposure from residential uses was >1,000. Based on these
assessments, it can be concluded that there is reasonable certainty of
no harm to the U.S. population or any population subgroup from exposure
to bifenazate.
2. Infants and children. The acute dietary exposure MOE was >22,000
for infants and children, and are well above EPA's standard acceptable
MOE of 100. The chronic dietary exposure was 1.3% of the RfD for
infants, and 1% for children. Exposure to potential residues in
drinking water is expected to be negligible, as DWLOC's are
substantially higher than modeled acute and long-term EEC's. The MOE's
from the limited potential for short-term exposure from residential
uses was <1,000. Based on these assessments, it can be concluded that
there is reasonable certainty of no harm to infants and children from
exposure to bifenazate.
F. International Tolerances
To date no Codex, Canadian or Mexican tolerances exist for
bifenazate.
[FR Doc. 01-9492 Filed 4-17-01; 8:45 a.m.]
BILLING CODE 6560-50-S
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