Carfentrazone-ethyl; Pesticide Tolerance
[Federal Register: September 30, 1998 (Volume 63, Number 189)]
[Rules and Regulations]
[Page 52174-52180]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr30se98-15]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
[OPP-300718; FRL-6032-1]
RIN 2070-AB78
Carfentrazone-ethyl; Pesticide Tolerance
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
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SUMMARY: This regulation establishes a tolerance for combined residues
of the herbicide Carfentrazone-ethyl (ethyl-alpha-2-dichloro-5-[-4-
(difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-1H-1,2,4-triazol-1-yl]-4-
fluorobenzene-propanoate) and its metabolite: Carfentrazone-ethyl
chloropropionic acid (alpha, 2-dichloro-5-[4-difluoromethyl)-4,5-
dihydro-3-methyl-5-oxo-1H-1,2,4-triazol-l-y]-4-fluorobenzenepropanoic
acid) in or on these raw agricultural commodities: corn, field, grain
at 0.1ppm; corn, field, forage at 0.1ppm; corn, field, fodder at 0.1
ppm; soybean seed at 0.1 ppm; wheat grain at 0.1 ppm; wheat forage at
1.0 ppm; wheat hay at 0.3 ppm; and wheat straw at 0.2 ppm. FMC
Corporation requested this tolerance under the Federal Food, Drug and
Cosmetic Act (FFDCA), as amended by the Food Quality Protection Act of
1996 (Pub. L. 104-170).
DATES: This regulation is effective September 30, 1998. Objections and
requests for hearings must be received by EPA on or before November 30,
1998.
ADDRESSES: Written objections and hearing requests, identified by the
docket control number, [OPP-300718], must be submitted to: Hearing
Clerk (1900), Environmental Protection Agency, Rm. M3708, 401 M St.,
SW., Washington, DC 20460. Fees accompanying objections and hearing
requests shall be labeled ``Tolerance Petition Fees'' and forwarded to:
EPA Headquarters Accounting Operations Branch, OPP (Tolerance Fees),
P.O. Box 360277M, Pittsburgh, PA 15251. A copy of any objections and
hearing requests filed with the Hearing Clerk identified by the docket
control number, [OPP-300718], must also be submitted to: Public
Information and Records Integrity Branch, Information Resources and
Services Division (7502C), Office of Pesticide Programs, Environmental
Protection Agency, 401 M St., SW., Washington, DC 20460. In person,
bring a copy of objections and hearing requests to Rm. 119, Crystal
Mall (CM)
[[Page 52175]]
#2, 1921 Jefferson Davis Hwy., Arlington, VA.
A copy of objections and hearing requests filed with the Hearing
Clerk may also be submitted electronically by sending electronic mail
(e-mail) to: opp-docket@epamail.epa.gov. Copies of objections and
hearing requests must be submitted as an ASCII file avoiding the use of
special characters and any form of encryption. Copies of objections and
hearing requests will also be accepted on disks in WordPerfect 5.1/6.1
file format or ASCII file format. All copies of objections and hearing
requests in electronic form must be identified by the docket control
number [OPP-300718]. No Confidential Business Information (CBI) should
be submitted through e-mail. Electronic copies of objections and
hearing requests on this rule may be filed online at many Federal
Depository Libraries.
FOR FURTHER INFORMATION CONTACT: By mail: Joanne I. Miller, Product
Manager, Registration Division (7505C), Office of Pesticide Programs,
Environmental Protection Agency, 401 M St., SW., Washington, DC 20460.
Office location, telephone number, and e-mail address: CM #2, 1921
Jefferson Davis Hwy., Arlington, VA, (703) 305-6224, e-mail:
miller.joanne@epamail.epa.gov.
SUPPLEMENTARY INFORMATION: In the Federal Register of January 30, 1998
(63 FR 4631)(FRL-5766-2), EPA, issued a notice pursuant to section 408
of the Federal Food, Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 346a(e)
announcing the filing of a pesticide petition (PP) for tolerance by FMC
Corporation. This notice included a summary of the petition prepared by
FMC Corporation, the registrant. There were no comments received in
response to the notice of filing.
The petition requested that 40 CFR part 180 be amended by
establishing tolerances for the herbicide, in or on corn, field, grain
at 0.1 parts per million (ppm); corn, field, forage at 0.1 ppm; corn,
field, fodder at 0.1 ppm; soybean seed at 0.1 ppm; wheat grain at 0.1
ppm; wheat forage at 1.0 ppm; wheat hay at 0.3 ppm; and wheat straw at
0.2 ppm.
I. Risk Assessment and Statutory Findings
Section 408(b)(2)(A)(i) of the FFDCA allows EPA to establish a
tolerance (the legal limit for a pesticide chemical residue in or on a
food) only if EPA determines that the tolerance is ``safe.'' Section
408(b)(2)(A)(ii) defines ``safe'' to mean that ``there is a reasonable
certainty that no harm will result from aggregate exposure to the
pesticide chemical residue, including all anticipated dietary exposures
and all other exposures for which there is reliable information.'' This
includes exposure through drinking water and in residential settings,
but does not include occupational exposure. Section 408(b)(2)(C)
requires EPA to give special consideration to exposure of infants and
children to the pesticide chemical residue in establishing a tolerance
and to ``ensure that there is a reasonable certainty that no harm will
result to infants and children from aggregate exposure to the pesticide
chemical residue. . . .''
EPA performs a number of analyses to determine the risks from
aggregate exposure to pesticide residues. For further discussion of the
regulatory requirements of section 408 and a complete description of
the risk assessment process, see the Final Rule on Bifenthrin Pesticide
Tolerances published in the Federal Register of November 26, 1997 (62
FR 62961)(FRL-5754-7).
II. Aggregate Risk Assessment and Determination of Safety
Consistent with section 408(b)(2)(D), EPA has reviewed the
available scientific data and other relevant information in support of
this action. EPA has sufficient data to assess the hazards of
Carfentrazone-ethyl and to make a determination on aggregate exposure,
consistent with section 408(b)(2), for a tolerance on corn, field,
grain at 0.1 part ppm; corn, field, forage at 0.1 ppm; corn, field,
fodder at 0.1 ppm; soybean seed at 0.1 ppm; wheat grain at 0.1 ppm;
wheat forage at 1.0 ppm; wheat hay at 0.3 ppm; and wheat straw at 0.2
ppm. EPA's assessment of the dietary exposures and risks associated
with establishing the tolerance follows.
A. Toxicological Profile
EPA has evaluated the available toxicity data and considered its
validity, completeness, and reliability as well as the relationship of
the results of the studies to human risk. EPA has also considered
available information concerning the variability of the sensitivities
of major identifiable subgroups of consumers, including infants and
children. The nature of the toxic effects caused by Carfentrazone-ethyl
are discussed below.
1. A battery of acute toxicity studies places the technical-grade
herbicide in Toxicity categories III and IV. No evidence of
sensitization was observed following dermal application in guinea pigs.
2. A 90-day subchronic feeding study was conducted in rats at
intake levels of 0, 58, 226, 470, 831 and 1,197 miligrams/kilograms/day
(mg/kg/day) for males and 0, 72, 284, 578, 1,008 and 1,427 mg/kg/day in
females, respectively. The No-Observed-Adverse-Effect-Level (NOAEL) was
226 mg/kg/day in males and 284 mg/kg/day in females. The Lowest-
Observed-Effect-Level (LOEL) was 470 mg/kg/day in males and 578 mg/kg/
day in females based on decreases in body weight, reductions in food
consumption and histopathological lesions.
3. A 90-day subchronic feeding study was conducted in mice at
dietary intake doses of 0, 143, 571, 1,143, 2,000 and 1,857 mg/kg/day.
The LOEL was 1,143 mg/kg/day based on findings in the liver pathology.
The NOAEL was 571 mg/kg/day.
4. A 90-day subchronic feeding study in dogs administered by
dietary admix doses of 0, 50, 150, 500 and 1,000 mg/kg/day. The NOAEL
was 50 mg/kg/day and the LOEL was 150 mg/kg/day based on systemic
toxicity (decrease in the rate of weight gain in females and an
increase in porphyrin levels in both sexes).
5. An 18-month mouse carcinogenicity study was conducted in mice at
dietary intake doses of 0, 10, 110 and 1,090 mg/kg/day for males and 0,
12, 119 and 1,296 mg/kg/day for females). The study found the compound
to be noncarcinogenic to mice under the conditions of the study. The
systemic NOAEL was 70 ppm (equivalent to 10 mg/kg/day for males and 12
mg/kg/day for females), and the systemic LOEL was 700 ppm (equivalent
to 110 mg/kg/day for males and 119 mg/kg/day for females) based on
increased mortality and microscopic signs of hepatotoxicity.
6. A 2-year rat chronic toxicity/carcinogenicity study was
conducted in rats at intake levels of 0, 2, 9, 37 and 188 mg/kg/day for
males and 0, 3, 12, 49 and 242 mg/kg/day for females. The study found
the compound to be noncarcinogenic to rats under the conditions of the
study. The NOAEL was 200 ppm (9 mg/kg/day ) for males and 50 ppm (3 mg/
kg/day) for females respectively and the LOEL was 800 ppm (37 mg/kg/
day) for males and 200 ppm (12 mg/kg/day) for females, based on liver
histopathology and total urinary porphyrin.
7. A 1-year feeding study in dogs dosed at levels of 0, 50, 150,
500 and 1,000 mg/kg/day in both sexes with a NOAEL of 50 mg/kg/day and
a LOEL of 150 mg/kg/day, based on an increase mean total urinary
porphyrins.
8. A developmental toxicity study in rats was conducted in rats at
dose levels of 0, 100, 600, and 1,250 mg/kg/day in
[[Page 52176]]
females, with a maternal LOEL of 600 mg/kg/day based on staining of the
abdominogenital area and maternal NOAEL of 100 mg/kg/day, and a
developmental LOEL of 1,250 mg/kg/day based upon a significant increase
in the litter incidences of wavy and thickened ribs; and a
developmental NOAEL of 600 mg/kg/day.
9. A developmental toxicity study in rabbits was conducted at
gavage dose levels of 0, 10, 40, 150 and 300 mg/kg/day. Evidence of
treatment-related maternal toxicity consisted of unthriftiness and
emaciation in two does at 300 mg/kg/day. There were no treatment-
related mortalities or gross pathological findings. No effects on body
weight, body weight change, or organ weight data were identified at any
treatment level. However, when considered in conjunction with the
findings of the two pilot dose-setting studies, which were conducted at
higher dose levels and which identified a steep dose-reponse curve with
maternal mortality occuring at doses of 350 mg/kg/day and above, it was
determined that 300 mg/kg/day provided an adequate high-dose assessment
of maternal toxicity in rabbits. The maternal toxicity NOAEL is greater
than/equal to 150 mg/kg/day and maternal LOEL of 300 mg/kg/day. There
was no evidence of treatment-related prenatal development toxicity, the
developmental LOEL was not determined and the developmental NOAEL is
greater than/equal to 300 mg/kg/day.
10. A 2-generation reproduction study in the rat at dietary levels
of 0, 8.6, 42.4, 127, 343 mg/kg/day for males, and 0, 9.5, 47.8, 142,
and 387 mg/kg/day for females established a parental NOAEL for systemic
and reproductive/developmental parameters of 127 mg/kg/day for males
and 142 mg/kg/day for females. The parental LOEL for systemic and
reproductive development parameters was 343 mg/kg/day for males and 387
mg/kg/day for females. There was no systemic toxicity demonstrated at
dose levels of less than/equal to 1,500 ppm. There were no treatment-
related clinical signs of toxicity or increases in mortality at any
dose levels. The offspring NOAEL was 142 mg/kg/day and the LOEL was 387
mg/kg/day. The NOAEL for reproductive toxicity was greater than/equal
to 387 mg/kg/day; the highest dose tested. There were no clinical signs
of toxicity reported for the pups of either generation.
11. In an acute neurotoxicity study in rats at gavage doses of 0,
500, 1,000, and 2,000 mg/kg, a NOAEL of 500 mg/kg and a LOEL of 1,000
mg/kg were based upon clinical observations (i.e., salivation) and
motor activity. There was no evidence of neuropathology.
12. A 90-day subchronic neurotoxicity study in the rat was
conducted at dietary levels of 0, 59, 603, and 1,178 mg/kg/day for
males and 0, 71, 718 and 1,434 mg/kg/day for females, with a NOAEL of
59 mg/kg/day for males and 71 mg/kg/day for females. The LOEL was 603
mg/kg/day for males and 718 mg/kg/day for females based on decreased
body weight.
13. Two reverse gene mutation assays (salmonella typhimurium) at
dose yielded negative results, both with and without metabolic
activation.
14. In vitro mammalian cell forward gene mutation assay in Chinse
hampster Ovary (CHO) cells yielded negative results both with and
without activation.
15. In vitro chromosomal abberation assay yielded positive results
under nonactivated conditions following doses of 3.75, 12.5, 37.5 and
125 <greek-m>g/ml. There were consistent and statistically significant
increased incidences of cells with aberrations at 125 <greek-m>g/ml,
the highest dose tested in the absence of metabolic activation.
16. In vivo mouse micronucleus cytogenic assay test was negative
for clastogenic and/or aneugenic activity, following intraperitoneal
injection doses of 600, 1,200, and 2,400 mg/kg. Dosed animals showed no
reduction in the ratio of polychromatic erythrocytes to total
erythrocytes. There was no evidence of polychromatic erythrocytes
associated with exposure to the test material.
17. An unscheduled in vivo/in vitro DNA synthesis assay was
negative following a single IP injection doses of 750, 1,500, 3,000 mg/
kg. Slight lethargy was seen in the high dose animals. Higher levels
(4,000 mg/kg/) were lethal in a preliminary study. Cytotoxicity for the
hepatocytes was not apparent at any dose. The results obtained with the
positive controls confirmed the sensitivity of the test system to
detect UDS. There was, however, no evidence that the test material
induced agenotoxic response at any dose or sacrifice time.
18. A metabolism study in rats indicated that approximately 72.4 to
87% of the administered dose of carefentrazone-ethyl was rapidly
absorbed and excreted in the urine within 24 hours after dosing. The
major metabolites in both the urine and feces were F8426-
chloropropionic acid (48.4 to 66.06%). The proposed metabolic pathway
appeared to be the conversion of the parent compound by hydrolysis of
the ester moiety to form F8426-chloropropionic acid, followed by
oxidative hydroxylation of the methyl group to form 3-hydroxymethyl-
F8426-chloropropionic acid, or dehydrochlorination to form F8426-
cinnamic acid.
B. Toxicological Endpoints
1. Acute toxicity. In an acute neurotoxicity study in rats and
using an uncertainty factor of 100 (10 x for inter-species
extrapolation, 10 x for intra-species variability, an acute referenced
dose (RfD) of 5 mg/kg/day was established, based on a NOAEL of 500 mg/
kg/day. A LOEL of 1,000 mg/kg/day was based on clinical observations
and motor activity testing.
A developmental toxicity study resulted in a NOAEL of 100 mg/kg/day
and the LOEL was 600 mg/kg/day. The finding was a result of the
interference of Carfentrazone-ethyl with porphyrin metabolism. It is
obvious that repeated doses of 600 mg/kg/day caused that interference;
one dose will cause interference also but the effect will not be
pronounced. Therefore, the NOAEL was not selected for this risk
assessment (i.e., for acute exposure).
2. Short - and intermediate - term toxicity. No dermal or systemic
toxicity was seen following repeated dermal application at 0, 100, 500
and 1,000 mg/kg/day, 6 hours/day, 5 days/week for 21 consecutive days
to male and female Sprague-Dawley rats. Also, in the oral developmental
toxicity study, no developmental toxicity was seen in rabbits and rats.
In the rabbits, the developmental NOAEL was 300 mg/kg/day (the highest
dose tested). In the rats, the developmental NOAEL was 600 mg/kg/day
and the developmental LOEL was 1,250 mg/kg/day (slightly higher than
the Limit-Dose) based on increase in the litter incidence of wavy and
thickened ribs. Therefore, based on the lack of systemic toxicity via
the dermal route and the occurrence of developmental toxicity only at
high doses in rats, the Health Effects Division's Hazard Identification
Assessment Review Committee (HED HIARC) determined that there are no
toxicological endpoints of concern for dermal risk assessments.
3. Chronic toxicity. EPA has established the RfD for Carfentrazone-
ethyl at 0.03 mg/kg/day. This RfD is based on the NOAEL of 3 mg/kg/day
established in a 2-year chronic toxicity/carcinogenicity study in rats
and using an uncertainty factor of 100 (10 x for inter-species
extrapolation, 10 x for intra-species variability. The LOEL of 12 mg/
kg/day was based on liver histopathology (increases in microscopic red
fluorescence of the
[[Page 52177]]
liver, liver pigment) and total mean urinary porphyrin observed at both
sexes.
4. Carcinogenicity. The Office of Pesticide Programs' HED HIARC
classified Carfentrazone-ethyl as a ``not likely'' human carcinogen
according to EPA Proposed Guidelines for Carcinogen Risk Assessment
(April 10, 1996).
C. Exposures and Risks
1. From food and feed uses. No previous tolerances have been
established for the combined residues of Carfentrazone-ethyl and its
chloropropionic acid. Risk assessments were conducted by EPA to
assessed dietary exposures from Carfentrazone-ethyl as follows:
i. Acute exposure and risk. Acute dietary risk assessments are
performed for a food-use pesticide if a toxicological study has
indicated the possibility of an effect of concern occurring as a result
of a one day or single exposure. The Dietary Risk Evaluation System
(DRES) acute dietary exposure analysis estimates the distribution of
single-day exposures for the overall U.S. population and certain
subgroups. The analysis evaluates individual food consumption as
reported by respondents in the United States Department of Agriculture
(USDA) 1989-92 Nationwide Food Consumption Survey (NFCS) and
accumulates exposure to the chemical for each commodity. Each analysis
assumes uniform distribution of Carfentrazone-ethyl in the commodity
supply. The acute percentages of the RfD were <1% for the U.S.
population and all subgroups. This is also a highly conservative risk
estimate in which 100% crop treated and tolerance level residues were
used.
ii. Chronic exposure and risk. A chronic dietary exposure analysis
from food source was conducted using tolerance level residues and 100%
crop treated information to estimate the Theoretical Maximum Residue
Contribution (TMRC) for the general population and 22 subgroups. The
TRMC for the general population represents 1% of the RfD, 1.3% for all
infants (<1 year), 0.4% for nursing infants (<1 year), 1.7% for non-
nursing infants (<1 year), 2.3% for children (1-6 years), 1.7% for
children (7-12 years), 0.9% for females (13+/nursing), and 1.2% for
males (13-19 years). This is a highly conservative risk estimate. No
refinements for percent crop treated or anticipated residues were made.
2. From drinking water. Carfentrazone-ethyl is moderately soluble
in water (12 ppm). Its mobility in soil could not be determined in the
aged leaching study because of its rapid breakdown. The major degradate
chloropropionic acid has a high water solubility (910 ppm) and is very
mobile K<INF>ads</INF> = 0.4; K<INF>oc</INF> = 30-48).
EPA estimates exposure Carfentrazone-ethyl and its degradate
chloropropionic acid for both surface and groundwater based on
available modeling. Since there are no registered uses for
Carfentrazone-ethyl in the U.S., there are no monitoring data to
compare against the modeling. Environmental concentrations for surface
water were estimated using Generic expected environmental concentration
(GENEEC), a single event model. Groundwater calculations for parent
Carfentrazone-ethyl and degradate chloropropionic acid was based on the
SCI-GROW method.
i. Acute exposure and risk. Drinking water levels of concern
(DWLOC) were calculated for surface water for the parent compound and
its chloropropionic acid metabolite at 1.8 x 10<SUP>5</SUP> for
adults and 5 x 10<SUP>4</SUP> parts per billion (ppb) for infants and
children. Using the GENEEC model, available environmental fate data,
and very conservative assumptions, the estimated environmental
concentrations calculated were 1.2 ppb for parent Carfentrazone-ethyl
and 2.88 ppb for the chloropropionic acid metabolite. These values are
well below EPA's level of concern. DWLOC's for groundwater were not
calculated since the estimated environmental concentrations calculated
for groundwater using SCI-GROW model were all less than 1 ppb.
ii. Chronic exposure and risk. Because the Agency lacks sufficient
water-related exposure data to complete a comprehensive drinking water
risk assessment for many pesticides, EPA has commenced and nearly
completed a process to identify a reasonable yet conservative bounding
figure for the potential contribution of water-related exposure to the
aggregate risk posed by a pesticide. In developing the bounding figure,
EPA estimated residue levels in water for a number of specific
pesticides using various data sources. The Agency then applied the
estimated residue levels, in conjunction with appropriate toxicological
endpoints (RfD's or acute dietary NOAEL's) and assumptions about body
weight and consumption, to calculate, for each pesticide, the increment
of aggregate risk contributed by consumption of contaminated water.
While EPA has not yet pinpointed the appropriate bounding figure for
exposure from contaminated water, the ranges the Agency is continuing
to examine are all below the level that would cause Carfentrazone-ethyl
to exceed the RfD if the tolerance being considered in this document
were granted. The Agency has therefore concluded that the potential
exposures associated with Carfentrazone-ethyl in water, even at the
higher levels the Agency is considering as a conservative upper bound,
would not prevent the Agency from determining that there is a
reasonable certainty of no harm if the tolerance is granted.
3. From non-dietary exposure. There are no registered or proposed
residential uses for Carfentrazone-ethyl.
4. Cumulative exposure to substances with common mechanism of
toxicity. Section 408(b)(2)(D)(v) requires that, when considering
whether to establish, modify, or revoke a tolerance, the Agency
consider ``available information'' concerning the cumulative effects of
a particular pesticide's residues and ``other substances that have a
common mechanism of toxicity.''
EPA does not have, at this time, available data to determine
whether Carfentrazone-ethyl has a common mechanism of toxicity with
other substances or how to include this pesticide in a cumulative risk
assessment. Unlike other pesticides for which EPA has followed a
cumulative risk approach based on a common mechanism of toxicity,
Carfentrazone-ethyl does not appear to produce a toxic metabolite
produced by other substances. For the purposes of this tolerance
action, therefore, EPA has not assumed that Carfentrazone-ethyl has a
common mechanism of toxicity with other substances. For information
regarding EPA's efforts to determine which chemicals have a common
mechanism of toxicity and to evaluate the cumulative effects of such
chemicals, see the Final Rule for Bifenthrin Pesticide Tolerances (62
FR 62961, November 26, 1997).
D. Aggregate Risks and Determination of Safety for U.S. Population
1. Acute risk. EPA concludes with reasonable certainty that
residues of Carfentrazone-ethyl and its chloropropionic acid metabolite
would not result in unacceptable levels of aggregrate acute human
health risk at this time. Acute risk estimates associated with exposure
to Carfentrazone-ethyl in food and water do not exceed EPA's level of
concern. Acute percentages of the RfD (from food sources only) were
less than 1% for the U.S. population and all subgroups. DWLOC's
calculated for surface water for the parent compound and its
chloropropionic acid metabolite were 1.8 x 10<SUP>5</SUP> ppb for
adults and 5 x 10<SUP>4</SUP> ppb
[[Page 52178]]
for infants and children. Using the GENEEC model, available
environmental fate data, and very conservative assumptions, the
estimated environmental concentrations calculated were 1.2 ppb for
parent Carfentrazone-ethyl and 2.88 ppb for chloropropionic acid
metabolite. These values are well below EPA's level of concern. DWLOC's
for groundwater were not calculated since the estimated environmental
concentrations calculated for groundwater using SCI-GROW model were all
less than 1 ppb.
2. Chronic risk. EPA concludes with reasonable certainty that
residues of Carfentrazone-ethyl and its chloropropionic acid metabolite
would not result in unacceptable levels of aggregate chronic human
health risk at this time. Chronic risk estimates associated with
exposure to Carfentrazone-ethyl in food and water do not exceed EPA's
level of concern. The chronic exposure analysis performed using
tolerance level residues and 100% crop treated information to estimate
the Theoretical Maximum Residue Contribution (TMRC) for the general
population and 22 subgroups yielded TMRC's for the general population
that represents 1% of the RfD, 1.3% for all infants (<1 year), 0.4% for
nursing infants (<1year), 1.7% for non-nursing infants (<1 year), 2.3%
for children (1-6 years), 1.7% for children (7-12 years), 0.9% for
females (13+/nursing), and 1.2% for males (13-19 years). The estimated
average concentration in surface water for Carfentrazone-ethyl (0.02
ppb) and for the chloropropionic acid (2.46 ppb) does not exceed
DWLOC's of 1 x 10<SUP>3</SUP> ppb for adults and 3 x 10<SUP>2</SUP>
ppb for children. Conservative model estimates (SCI-GROW) of the
concentration of Carfentrazone-ethyl and its chloropropionic acid in
groundwater indicate that exposure will be minimal, therefore DWLOC's
for chronic groundwater were not calculated.
3. Short- and intermediate-term risk. HED concludes with reasonable
certainty that residues of Carfentrazone-ethyl and its chloropropionic
acid metabolite would not result in unacceptable levels of short- and
intermediate-term human health risk. There are no residential uses or
exposure scenarios and no toxicological endpoints were identified for
short- and intermediate-term exposure scenarios.
4. Determination of safety. Based on these risk assessments, EPA
concludes that there is a reasonable certainty that no harm will result
from aggregate exposure to Carfentrazone-ethyl residues.
E. Aggregate Risks and Determination of Safety for Infants and Children
1. Safety factor for infants and children-- i. In general. In
assessing the potential for additional sensitivity of infants and
children to residues of Carfentrazone-ethyl, EPA considered data from
developmental toxicity studies in the rat and rabbit and a two-
generation reproduction study in the rat. The developmental toxicity
studies are designed to evaluate adverse effects on the developing
organism resulting from maternal pesticide exposure gestation.
Reproduction studies provide information relating to effects from
exposure to the pesticide on the reproductive capability of mating
animals and data on systemic toxicity.
FFDCA section 408 provides that EPA shall apply an additional
tenfold margin of safety for infants and children in the case of
threshold effects to account for pre-and post-natal toxicity and the
completeness of the database unless EPA determines that a different
margin of safety will be safe for infants and children. Margins of
safety are incorporated into EPA risk assessments either directly
through use of a margin of exposure (MOE) analysis or through using
uncertainty (safety) factors in calculating a dose level that poses no
appreciable risk to humans. EPA believes that reliable data support
using the standard uncertainty factor (usually 100 for combined inter-
and intra-species variability)) and not the additional tenfold MOE/
uncertainty factor when EPA has a complete data base under existing
guidelines and when the severity of the effect in infants or children
or the potency or unusual toxic properties of a compound do not raise
concerns regarding the adequacy of the standard MOE/safety factor.
ii. Pre- and post-natal sensitivity. EPA determined that a 10 x
safety factor for enhanced sensitivity to infants and children was not
required. The rationale is based on the following: there was no
indication of increased susceptibility of rats or rabbits to in utero
and/or postnatal exposure to the chemical; the toxicological database
is complete; and the fact that there are no registered residential
products, in conjunction with the use of generally high qualitiy data,
conservative models and/or assumptions in the exposure assessment
provide adequate protection for infants and children.
2. Acute risk. EPA concludes with reasonable certainty that
residues of Carfentrazone-ethyl and its chloropropionic acid metabolite
would not result in unacceptable levels of aggregate acute human health
risk at this time.
3. Chronic risk. EPA concludes with reasonable certainty that
residues of Carfentrazone-ethyl and its chloropropionic acid metabolite
would not result in unacceptable levels of aggregate chronic human
health risk at this time. Chronic risk estimates associated with
exposure to Carfentrazone-ethyl in food and water do not exceed EPA's
level of concern.
4. Determination of safety. Based on these risk assessments, EPA
concludes that there is a reasonable certainty that no harm will result
to infants and children from aggregate exposure to Carfentrazone-ethyl
residues.
III. Other Considerations
A. Metabolism In Plants and Animals
EPA decided that for the present crops (corn, wheat, soybeans), the
proposed tolerance expression for the combined residues of the
herbicide carfentrazone-ethyl (F8426) and its chloropropionic acid
metabolite is adquate for the plant and animal commodities. However,
since the hydroxyl metabolite, 3-OH-F8426-Cl-PAc, was found as the
major residue in soybean forage and hay, the registrant must also
monitor for this metabolite in all field trials of additional future
crops.
B. Analytical Enforcement Methodology
There is a practical analytical method for detecting and measuring
levels of Carfentrazone-ethyl and its metabolites in or on food with a
limit of detection that allows monitoring of food with residues at or
above the levels set in these tolerances. The proposed analytical
method for determining residues is hydrolysis followed by gas
chromatographic separation.
The method may be requested from: Calvin Furlow, PRRIB, IRSD
(7502C), Office of Pesticide Programs, Environmental Protection Agency,
401 M St., SW., Washington, DC 20460. Office location and telephone
number: Rm 101FF, CM #2, 1921 Jefferson Davis Hwy., Arlington, VA
22202, (703-305-5229).
C. International Residue Limits
There are no Codex, Canadian, or Mexican tolerances or maximum
residue limits established for Carfentrazone-ethyl in/on corn, wheat
and soybeans. There are no compatibility problems that exists between
the proposed U.S. and Codex tolerances.
[[Page 52179]]
D. Rotational Crop Restrictions
The labeling will require a 30 day plant-back interval for crops
other than small grains.
IV. Conclusion
Therefore, the tolerance is established for Carfentrazone-ethyl
(ethyl-alpha-2-dichloro-5-[-4-(difluoromethyl)-4,5-dihydro-3-methyl-5-
oxo-1H-1,2,4-triazol-1-yl]-4-fluorobenzene-propanoate) and its
metabolite: Carfentrazone-ethyl chloropropionic acid (alpha, 2-
dichloro-5-[4-difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-1H-1,2,4-
triazol-l-y]-4-fluorobenzenepropanoic acid) in or on corn grain, corn
forage, corn fodder, soybean seed, and wheat grain at 0.1ppm, wheat
forage at 1.0 ppm, wheat hay at 0.3 ppm, and wheat straw at 0.2 ppm.
V. Objections and Hearing Requests
The new FFDCA section 408(g) provides essentially the same process
for persons to ``object'' to a tolerance regulation issued by EPA under
new section 408(e) and (l)(6) as was provided in the old section 408
and in section 409. However, the period for filing objections is 60
days, rather than 30 days. EPA currently has procedural regulations
which govern the submission of objections and hearing requests. These
regulations will require some modification to reflect the new law.
However, until those modifications can be made, EPA will continue to
use those procedural regulations with appropriate adjustments to
reflect the new law.
Any person may, by November 30, 1998, file written objections to
any aspect of this regulation and may also request a hearing on those
objections. Objections and hearing requests must be filed with the
Hearing Clerk, at the address given above (40 CFR 178.20). A copy of
the objections and/or hearing requests filed with the Hearing Clerk
should be submitted to the OPP docket for this rulemaking. The
objections submitted must specify the provisions of the regulation
deemed objectionable and the grounds for the objections (40 CFR
178.25). Each objection must be accompanied by the fee or a request for
a fee waiver as specified in 40 CFR 180.33(i). If a hearing is
requested, the objections must include a statement of the factual
issues on which a hearing is requested, the requestor's contentions on
such issues, and a summary of any evidence relied upon by the requestor
(40 CFR 178.27). A request for a hearing will be granted if the
Administrator determines that the material submitted shows the
following: There is genuine and substantial issue of fact; there is a
reasonable possibility that available evidence identified by the
requestor would, if established, resolve one or more of such issues in
favor of the requestor, taking into account uncontested claims or facts
to the contrary; and resolution of the factual issues in the manner
sought by the requestor would be adequate to justify the action
requested (40 CFR 178.32). Information submitted in connection with an
objection or hearing request may be claimed confidential by marking any
part or all of that information as Confidential Business Information
(CBI). Information so marked will not be disclosed except in accordance
with procedures set forth in 40 CFR part 2. A copy of the information
that does not contain CBI must be submitted for inclusion in the public
record. Information not marked confidential may be disclosed publicly
by EPA without prior notice.
VI. Public Record and Electronic Submissions
EPA has established a record for this rulemaking under docket
control number [OPP-300718] (including any comments and data submitted
electronically). A public version of this record, including printed,
paper versions of electronic comments, which does not include any
information claimed as CBI, is available for inspection from 8:30 a.m.
to 4 p.m., Monday through Friday, excluding legal holidays. The public
record is located in Rm. 119 of the Public Information and Records
Integrity Branch, Information Resources and Services Division (7502C),
Office of Pesticide Programs, Environmental Protection Agency, CM #2,
1921 Jefferson Davis Hwy., Arlington, VA.
Electronic comments may be sent directly to EPA at:
opp-docket@epamail.epa.gov.
Electronic comments must be submitted as an ASCII file avoiding the
use of special characters and any form of encryption.
The official record for this rulemaking, as well as the public
version, as described above will be kept in paper form. Accordingly,
EPA will transfer any copies of objections and hearing requests
received electronically into printed, paper form as they are received
and will place the paper copies in the official rulemaking record which
will also include all comments submitted directly in writing. The
official rulemaking record is the paper record maintained at the
Virginia address in ADDRESSES at the beginning of this document.
VII. Regulatory Assessment Requirements
A. Certain Acts and Executive Orders
This final rule establishes a tolerance under FFDCA section 408(d)
in response to a petition submitted to the Agency. The Office of
Management and Budget (OMB) has exempted these types of actions from
review under Executive Order 12866, entitled Regulatory Planning and
Review (58 FR 51735, October 4, 1993). This final rule does not contain
any information collections subject to OMB approval under the Paperwork
Reduction Act (PRA), 44 U.S.C. 3501 et seq., or impose any enforceable
duty or contain any unfunded mandate as described under Title II of the
Unfunded Mandates Reform Act of 1995 (UMRA) (Pub. L. 104-4). Nor does
it require special considerations as required by Executive Order 12898,
entitled Federal Actions to Address Environmental Justice in Minority
Populations and Low-Income Populations (59 FR 7629, February 16, 1994),
or require OMB review in accordance with Executive Order 13045,
entitled Protection of Children from Environmental Health Risks and
Safety Risks (62 FR 19885, April 23, 1997).
In addition, since tolerances and exemptions that are established
on the basis of a petition under FFDCA section 408(d), such as the
tolerance in this final rule, do not require the issuance of a proposed
rule, the requirements of the Regulatory Flexibility Act (RFA) (5
U.S.C. 601 et seq.) do not apply. Nevertheless, the Agency has
previously assessed whether establishing tolerances, exemptions from
tolerances, raising tolerance levels or expanding exemptions might
adversely impact small entities and concluded, as a generic matter,
that there is no adverse economic impact. The factual basis for the
Agency's generic certification for tolerance actions published on May
4, 1981 (46 FR 24950) and was provided to the Chief Counsel for
Advocacy of the Small Business Administration.
B. Executive Order 12875
Under Executive Order 12875, entitled Enhancing Intergovernmental
Partnerships (58 FR 58093, October 28, 1993), EPA may not issue a
regulation that is not required by statute and that creates a mandate
upon a State, local or tribal government, unless the Federal government
provides the funds necessary to pay the direct compliance costs
incurred by those governments. If the mandate is unfunded, EPA must
[[Page 52180]]
provide to the Office of Management and Budget (OMB) a description of
the extent of EPA's prior consultation with representatives of affected
State, local and tribal governments, the nature of their concerns,
copies of any written communications from the governments, and a
statement supporting the need to issue the regulation. In addition,
Executive Order 12875 requires EPA to develop an effective process
permitting elected officials and other representatives of State, local
and tribal governments ``to provide meaningful and timely input in the
development of regulatory proposals containing significant unfunded
mandates.''
Today's rule does not create an unfunded federal mandate on State,
local or tribal governments. The rule does not impose any enforceable
duties on these entities. Accordingly, the requirements of section 1(a)
of Executive Order 12875 do not apply to this rule.
C. Executive Order 13084
Under Executive Order 13084, entitled Consultation and Coordination
with Indian Tribal Governments (63 FR 27655, May 19,1998), EPA may not
issue a regulation that is not required by statute, that significantly
or uniquely affects the communities of Indian tribal governments, and
that imposes substantial direct compliance costs on those communities,
unless the Federal government provides the funds necessary to pay the
direct compliance costs incurred by the tribal governments. If the
mandate is unfunded, EPA must provide OMB, in a separately identified
section of the preamble to the rule, a description of the extent of
EPA's prior consultation with representatives of affected tribal
governments, a summary of the nature of their concerns, and a statement
supporting the need to issue the regulation. In addition, Executive
Order 13084 requires EPA to develop an effective process permitting
elected and other representatives of Indian tribal governments ``to
provide meaningful and timely input in the development of regulatory
policies on matters that significantly or uniquely affect their
communities.''
Today's rule does not significantly or uniquely affect the
communities of Indian tribal governments. This action does not involve
or impose any requirements that affect Indian Tribes. Accordingly, the
requirements of section 3(b) of Executive Order 13084 do not apply to
this rule.
VIII. Submission to Congress and the Comptroller General
The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the
Small Business Regulatory Enforcement Fairness Act of 1996, generally
provides that before a rule may take effect, the agency promulgating
the rule must submit a rule report, which includes a copy of the rule,
to each House of the Congress and to the Comptroller General of the
United States. EPA will submit a report containing this rule and other
required information to the U.S. Senate, the U.S. House of
Representatives, and the Comptroller General of the United States prior
to publication of the rule in the Federal Register. This rule is not a
``major rule'' as defined by 5 U.S.C. 804(2).
List of Subjects in 40 CFR Part 180
Environmental protection, Administrative practice and procedure,
Agricultural commodities, Pesticides and pests, Reporting and
recordkeeping requirements.
Dated: September 23, 1998.
Marcia E. Mulkey,
Director, Office of Pesticide Programs.
Therefore, 40 CFR chapter I is amended as follows:
PART 180 ---- [AMENDED]
1. The authority citation for part 180 continues to read as
follows:
Authority: 21 U.S.C. 346a and 371.
2. Section 180.515 is revised to read as follows:
Sec. 180.515 Carfentrazone-ethyl; tolerances for residues
(a) General. Tolerances are established for combined residues of
the herbicide Carfentrazone-ethyl (ethyl-alpha-2-dichloro-5-[-4-
(difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-1H-1,2,4-triazol-1-yl]-4-
fluorobenzene-propanoate) and its metabolite: Carfentrazone-ethyl
chloropropionic acid (alpha, 2-dichloro-5-[4-difluoromethyl)-4,5-
dihydro-3-methyl-5-oxo-1H-1,2,4-triazol-l-y]-4-fluorobenzenepropanoic
acid) in or on the following raw agricultural commodities:
------------------------------------------------------------------------
Commodity Parts per million
------------------------------------------------------------------------
Corn, field............................... 0.1
Corn, field, fodder....................... 0.1
Corn, field, forage....................... 0.1
Soybean seed.............................. 0.1
Wheat forage.............................. 1.0
Wheat grain............................... 0.1
Wheat hay................................. 0.3
Wheat straw............................... 0.2
------------------------------------------------------------------------
(b) Section 18 emergency exemptions. [Reserved]
(c) Tolerances with regional registrations. [Reserved]
(d) Indirect or inadvertent residues. [Reserved]
[FR Doc. 98-26162 Filed 9-29-98; 8:45 am]
BILLING CODE 6560-50-F
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