[Federal Register Volume 76, Number 22 (Wednesday, February 2, 2011)]
[Rules and Regulations]
[Pages 5704-5711]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-1898]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
[EPA-HQ-OPP-2008-0125; FRL-8860-1]
Sulfentrazone; Pesticide Tolerances
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
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SUMMARY: This regulation establishes tolerances for residues of
sulfentrazone in or on multiple commodities. Additionally, this
regulation deletes existing tolerances on commodities superseded by the
establishment of crop subgroups. This regulation also deletes a time-
limited tolerance on bean, succulent seed without pod (lima bean and
cowpea), as the tolerance expired on December 31, 2007. Interregional
Research Project Number 4 (IR-4) requested these tolerances under the
Federal Food, Drug, and Cosmetic Act (FFDCA).
DATES: This regulation is effective February 2, 2011. Objections and
requests for hearings must be received on or before April 4, 2011, and
must be filed in accordance with the instructions provided in 40 CFR
part 178 (see also Unit I.C. of the SUPPLEMENTARY INFORMATION).
ADDRESSES: EPA has established a docket for this action under docket
identification (ID) number EPA-HQ-OPP-2008-0125. All documents in the
docket are listed in the docket index available at http://www.regulations.gov. Although listed in the index, some information is
not publicly available, e.g., Confidential Business Information (CBI)
or other information whose disclosure is restricted by statute. Certain
other material, such as copyrighted material, is not placed on the
Internet and will be publicly available only in hard copy form.
Publicly available docket materials are available in the electronic
docket at http://www.regulations.gov, or, if only available in hard
copy, at the OPP Regulatory Public Docket in Rm. S-4400, One Potomac
Yard (South Bldg.), 2777 S. Crystal Dr., Arlington, VA. The Docket
Facility is open from 8:30 a.m. to 4 p.m., Monday through Friday,
excluding legal holidays. The Docket Facility telephone number is (703)
305-5805.
FOR FURTHER INFORMATION CONTACT: Laura Nollen, Registration Division
(7505P), Office of Pesticide Programs, Environmental Protection Agency,
1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone
number: (703) 305-7390; e-mail address: [email protected].
SUPPLEMENTARY INFORMATION:
I. General Information
A. Does this action apply to me?
You may be potentially affected by this action if you are an
agricultural producer, food manufacturer, or pesticide manufacturer.
Potentially affected entities may include, but are not limited to those
engaged in the following activities:
Crop production (NAICS code 111).
Animal production (NAICS code 112).
Food manufacturing (NAICS code 311).
Pesticide manufacturing (NAICS code 32532).
This listing is not intended to be exhaustive, but rather to
provide a guide for readers regarding entities likely to be affected by
this action. Other types of entities not listed in this unit could also
be affected. The North American Industrial Classification System
(NAICS) codes have been provided to assist you and others in
determining whether this action might apply to certain entities. If you
have any 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 electronic access to other related information?
You may access a frequently updated electronic version of EPA's
tolerance regulations at 40 CFR part 180 through the Government
Printing Office's e-CFR site at http://www.gpoaccess.gov/ecfr.
C. How can I file an objection or hearing request?
Under FFDCA section 408(g), 21 U.S.C. 346a, any person may file an
objection to any aspect of this regulation and may also request a
hearing on those objections. You must file your objection or request a
hearing on this regulation in accordance with the instructions provided
in 40 CFR part 178. To ensure proper receipt by EPA, you must identify
docket ID number EPA-HQ-OPP-2008-0125 in the subject line on the first
page of your submission. All objections and requests for a hearing must
be in writing, and must be received by the Hearing Clerk on or before
April 4, 2011. Addresses for mail and hand delivery of objections and
hearing requests are provided in 40 CFR 178.25(b).
In addition to filing an objection or hearing request with the
Hearing Clerk as described in 40 CFR part 178, please submit a copy of
the filing that does not contain any CBI for inclusion in the public
docket. Information not marked confidential pursuant to 40 CFR part 2
may be disclosed publicly by EPA without prior notice. Submit a copy of
your non-CBI objection or hearing request, identified by docket ID
number EPA-HQ-OPP-2008-0125, by one of the following methods:
Federal eRulemaking Portal: http://www.regulations.gov.
Follow the on-line instructions for submitting comments.
Mail: Office of Pesticide Programs (OPP) Regulatory Public
Docket (7502P), Environmental Protection Agency, 1200 Pennsylvania
Ave., NW., Washington, DC 20460-0001.
Delivery: OPP Regulatory Public Docket (7502P),
Environmental Protection Agency, Rm. S-4400, One Potomac Yard (South
Bldg.), 2777 S. Crystal Dr., Arlington, VA. Deliveries are only
accepted during the Docket Facility's normal hours of operation (8:30
a.m. to 4 p.m., Monday through Friday, excluding legal holidays).
[[Page 5705]]
Special arrangements should be made for deliveries of boxed
information. The Docket Facility telephone number is (703) 305-5805.
II. Summary of Petitioned-For Tolerances
In the Federal Register of March 12, 2008 (73 FR 13225) (FRL-3854-
6), EPA issued a notice pursuant to section 408(d)(3) of FFDCA, 21
U.S.C. 346a(d)(3), announcing the filing of a pesticide petition (PP
7E7308) by IR-4, 500 College Road East, Suite 201 W., Princeton, NJ
08540. The petition requested that 40 CFR 180.498 be amended by
establishing tolerances for residues of the combined free and
conjugated residues of the herbicide sulfentrazone, [N-[2,4-dichloro-5-
[4-(difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-1H-1,2,4-triazol-1-
yl]phenyl]methanesulfonamide] and its metabolites HMS [N-(2,4-dichloro-
5-(4-(difluoromethyl)-4,5-dihydro-3-hydroxymethyl-5-oxo-1H-1,2,4-
triazol-1-yl)phenyl)methanesulfonamide] and DMS [(N-2,4-dichloro-5-[4-
(difluoromethyl)-4,5-dihydro-5-oxo-1H-1,2,4-triazol-1-
yl)phenyl)methanesulfonamide] in or on food commodities Brassica, head
and stem, subgroup 5A at 0.20 parts per million (ppm); Brassica, leafy
greens, subgroup 5B at 0.35 ppm; melon, subgroup 9A at 0.10 ppm;
vegetable, fruiting, group 8 at 0.05 ppm; okra at 0.05 ppm; pea,
succulent at 0.05 ppm; flax at 0.05 ppm; strawberry at 0.05 ppm; and
vegetable, tuberous and corn, subgroup 1C at 0.15 ppm. That notice
referenced a summary of the petition prepared on behalf of IR-4 by FMC
Corporation, the registrant, which is available in the docket, http://www.regulations.gov. Comments were received on the notice of filing.
EPA's response to these comments is discussed in Unit IV.C.
Based upon review of the data supporting the petition, EPA has
revised the proposed tolerance levels for several commodities.
Additionally, the EPA has assessed several additional fruiting
vegetable commodities in order to establish the revised and expanded
fruiting vegetable group 8-10. EPA has also revised the tolerance
expression for all established commodities to be consistent with
current Agency policy. The reasons for these changes are explained in
Unit IV.D.
III. Aggregate Risk Assessment and Determination of Safety
Section 408(b)(2)(A)(i) of 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) of FFDCA 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) of FFDCA 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. * *
*''
Consistent with section 408(b)(2)(D) of FFDCA, and the factors
specified in section 408(b)(2)(D) of FFDCA, 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 and to
make a determination on aggregate exposure for sulfentrazone including
exposure resulting from the tolerances established by this action.
EPA's assessment of exposures and risks associated with sulfentrazone
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.
Sulfentrazone has low acute toxicity via the oral, dermal, and
inhalation routes of exposure. It is a mild eye irritant, but not a
dermal irritant or sensitizer. Subchronic and chronic toxicity studies
in rats, mice and dogs identified the hematopoietic system as the
target of sulfentrazone. Protoporphyrinogen oxidase inhibition in the
mammalian species may result in disruption of heme synthesis. In these
studies, disruption of heme synthesis was observed at about the same
dose levels across species except in the case of mice, where the
effects were seen at a slightly higher dose. The hematotoxicity
occurred around the same dose level for short- through long-term
exposure without increasing in severity.
In the oral and dermal rat developmental toxicity studies,
decreased fetal body weights and reduced/delayed skeletal ossifications
were noted at doses that were not maternally toxic. In rabbits,
developmental effects such as decreased pup viability were observed at
a maternally toxic dose (clinical signs, abortions and decreased body
weight gains). In the 2-generation reproduction study in rats,
offspring effects such as decreased body weights and decreased litter
survival were observed at a maternally toxic dose (slightly decreased
body weight gain).
In the acute neurotoxicity study, an increased incidence of
clinical signs (staggered gait, splayed hind limbs, and abdominal
gripping), changes in functional observation battery (FOB) parameters,
and decreased motor activity were observed; however, complete recovery
was observed within 14 days and there was no evidence of
neuropathology. In the subchronic neurotoxicity study, clinical signs
of toxicity, increased motor activity, and/or decreased body weights,
body weight gain, and food consumption were observed. There was no
evidence of neuropathology in either study. In a published, non-
guideline developmental toxicity study in the rat (de Castro, et al.,
2007), several dose-dependent effects (delayed ear opening, decreased
grip response and rearing frequency, and increased surface righting
reflex reaction time) were reported in pups whose mothers were treated
with sulfentrazone. However, this study had several shortcomings that
limit its use for regulatory purposes.
Carcinogenicity studies in rats and mice showed no evidence of
increased incidence of tumor formation due to treatment with
sulfentrazone. Therefore, the EPA classified sulfentrazone as ``not
likely to be carcinogenic to humans.'' The available mutagenicity
studies indicate that sulfentrazone is weakly clastogenic in the in
vitro mouse lymphoma assay in the absence of S9 activation; however,
the response was not evident in the presence of S9 activation.
Sulfentrazone is neither mutagenic in bacterial cells, nor clastogenic
in male or female mice in vivo.
Specific information on the studies received and the nature of the
adverse effects caused by sulfentrazone as well as the no-observed-
adverse-effect-level (NOAEL) and the lowest-observed-adverse-effect-
level (LOAEL) from the toxicity studies can be found at http://www.regulations.gov in document: ``Sulfentrazone; REVISED Section 3
Registration Request to Add New Uses on: Brassica, Head and Stem,
Subgroup 5A; Brassica, Leafy Greens, Subgroup 5B; Melon, Subgroup 9A;
Fruiting
[[Page 5706]]
Vegetable, Group 8 and Okra; Pea, Succulent; Flax; Strawberry; and
Tuberous and Corm Vegetable, Subgroup 1C. Human-Health Risk
Assessment.'' pp. 51-56 in docket ID number EPA-HQ-OPP-2008-0125.
B. Toxicological Points of Departure/Levels of Concern
Once a pesticide's toxicological profile is determined, EPA
identifies toxicological points of departure (POD) and levels of
concern (LOC) to use in evaluating the risk posed by human exposure to
the pesticide. For hazards that have a threshold below which there is
no appreciable risk, the toxicological POD is used as the basis for
derivation of reference values for risk assessment. PODs are developed
based on a careful analysis of the doses in each toxicological study to
determine the dose at the NOAEL and the lowest dose at which adverse
effects of concern are identified (the LOAEL). Uncertainty/safety
factors are used in conjunction with the POD to calculate a safe
exposure level--generally referred to as a population-adjusted dose
(PAD) (a = acute, c = chronic) or a reference dose (RfD)--and a safe
margin of exposure (MOE). For non-threshold risks, the Agency assumes
that any amount of exposure will lead to some degree of risk. Thus, the
Agency estimates risk in terms of the probability of an occurrence of
the adverse effect expected in a lifetime. For more information on the
general principles EPA uses in risk characterization and a complete
description of the risk assessment process, see http://www.epa.gov/pesticides/factsheets/riskassess.htm.
The doses and toxicological endpoints selected for several exposure
scenarios including the acute dietary endpoints for females 13-49 years
old, the chronic dietary endpoint, and the short- and intermediate-term
inhalation endpoint have been revised since the last risk assessment
based on a re-evaluation of the toxicology database. The updated
endpoints are protective of sulfentrazone's developmental toxicity,
which was the critical effect in the database and observed via both the
oral and dermal routes of exposure.
The acute dietary endpoint is based on increased gestation
duration, reduced prenatal viability (fetal and litter), reduced litter
size, increased number of stillborn pups, reduced postnatal survival
(pups and litter), and pup body weight deficits throughout lactation in
both generations of offspring observed in a 2-generation reproductive
toxicity study in rats. The developmental effects were reported in the
presence of mild maternal toxicity (slightly decreased body-weight
gain, particularly in F1 females). It has been EPA's
practice to consider various forms of developmental toxicity such as
reduced prenatal viability, reduced litter size, and increased number
of stillborn pups as single-dose effects and, therefore, relevant for
the acute dietary (females aged 13-49) exposure scenario, in order to
protect against potential exposure of pregnant females. It should be
noted that the fetal body weight deficits and retardation in skeletal
development (including decreased numbers of caudal vertebral and
metacarpal ossification sites) reported in the oral rat prenatal
developmental toxicity study were also evaluated for this acute dietary
endpoint. However, it was concluded that such effects are unlikely due
to a single dose event and are more appropriate for a repeated-exposure
scenario. Furthermore, EPA has not traditionally considered delays in
ossification (and related fetal body weight deficits) to be single dose
effects.
The chronic dietary endpoint is based on developmental toxicity
(decreased fetal weights and delay in skeletal ossification) that was
observed in the oral developmental toxicity study in the rat. This
study provides the lowest NOAEL in the database, and the effects are
similar to those observed in offspring (decreased body weight) at a
slightly higher dose in the 2-generation reproduction study in rats. In
addition, choice of the developmental toxicity study in the rat
protects against exposure of women throughout their entire lifespan,
which includes their childbearing years.
The short- and intermediate-term inhalation endpoints are based on
developmental toxicity (decreased fetal weights, delay in skeletal
ossification) that was observed in the oral developmental toxicity
study in the rat. An oral study was chosen for this exposure scenario
in the absence of an inhalation toxicity study. Assuming 100%
absorption via the inhalation route, the oral developmental toxicity
study protects pregnant women who might be exposed via inhalation
against the critical effect observed in the sulfentrazone database,
developmental toxicity.
The endpoints for the other exposure scenarios remain the same. A
summary of the toxicological endpoints for sulfentrazone used for human
risk assessment is shown in Table 1 of this unit.
Table 1--Summary of Toxicological Doses and Endpoints for Sulfentrazone for Use in Human Health Risk Assessment
----------------------------------------------------------------------------------------------------------------
Point of
departure and RfD, PAD, LOC for
Exposure/scenario uncertainty/ risk assessment Study and toxicological effects
safety factors
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Acute dietary................. NOAEL = 14 Acute RfD = 0.14 2-Generation Reproductive Toxicity Study--
(Females 13-49 years of age).. milligrams/ mg/kg/day. Rat, Offspring Toxicity LOAEL= 33 (M) and
kilogram/day (mg/ aPAD = 0.14 mg/kg/ 40 (F) mg/kg/day based on reduced
kg/day). day. prenatal viability (fetal & litter),
UFA = 10x........ reduced litter size, increased number of
UFH = 10x........ stillborn pups, reduced pup and litter
FQPA SF = 1x..... postnatal survival and decreased pup body
weights throughout lactation.
Acute dietary................. NOAEL = 250 mg/kg/ Acute RfD = 2.5 Acute-Neurotoxicity Study--Rat, LOAEL =
(General population including day. mg/kg/day. 750 mg/kg/day based on increased
infants and children). UFA = 10x........ aPAD = 2.5 mg/kg/ incidence of clinical signs and FOB
UFH = 10x........ day. parameters and decreased motor activity.
FQPA SF = 1x.....
Chronic dietary (All NOAEL= 10 mg/kg/ Chronic RfD = 0.1 Prenatal Developmental Toxicity--Rat,
populations). day. mg/kg/day. Developmental LOAEL = 25 mg/kg/day, based
UFA = 10x........ cPAD = 0.1 mg/kg/ upon decreased mean fetal weights, and
UFH = 10x........ day. retardation in skeletal development
FQPA SF = 1x..... evidenced by an increased number of
litters with any variation and by
decreased number of caudal vertebral and
metacarpal ossification sites.
[[Page 5707]]
Incidental oral short-term (1 NOAEL= 14 mg/kg/ LOC for MOE = 100 2-Generation Reproduction Study--Rat,
to 30 days) and intermediate- day. LOAEL = 33 mg/kg/day based on decreased
term (1 to 6 months). UFA = 10x........ pup body weights during lactation and
UFH = 10x........ reduced postnatal survival in both
FQPA SF = 1x..... generations.
Dermal short-term (1 to 30 Dermal (or oral) LOC for MOE = 100 Dermal Developmental Study--Rat, LOAEL =
days) and intermediate-term. study NOAEL = 250 mg/kg/day based on decreased fetal
(1 to 6 months)............... 100 mg/kg/day. body weight; increased incidences of
UFA = 10x........ fetal variations: hypoplastic or wavy
UFH = 10x........ ribs, incompletely ossified lumbar
FQPA SF = 1x..... vertebral arches, and incompletely
ossified ischia or pubes; and reduced
number of thoracic vertebral and rib
ossification sites.
Inhalation short-term (1 to 30 Inhalation (or LOC for MOE = 100 Prenatal Developmental Toxicity--Rat,
days). oral) study Developmental LOAEL = 25 mg/kg/day, based
NOAEL= 10 mg/kg/ upon decreased mean fetal weights, and
day (inhalation retardation in skeletal development
absorption rate evidenced by an increased number of
= 100%). litters with any variation and by
UFA = 10x........ decreased number of caudal vertebral and
UFH = 10x........ metacarpal ossification sites.
FQPA SF = 1x.....
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Cancer (Oral, dermal, Sulfentrazone is classified as ``not likely to be carcinogenic to humans.''
inhalation).
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UFA = extrapolation from animal to human (interspecies). UFH = potential variation in sensitivity among members
of the human population (intraspecies). UFL = use of a LOAEL to extrapolate a NOAEL. UFS = use of a short-term
study for long-term risk assessment. UFDB = to account for the absence of data or other data deficiency. FQPA
SF = Food Quality Protection Act Safety Factor.
C. Exposure Assessment
1. Dietary exposure from food and feed uses. In evaluating dietary
exposure to sulfentrazone, EPA considered exposure under the
petitioned-for tolerances as well as all existing sulfentrazone
tolerances in 40 CFR 180.498. EPA assessed dietary exposures from
sulfentrazone in food as follows:
i. Acute exposure. Quantitative acute dietary exposure and 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 1-day or single exposure. Such effects were identified
for sulfentrazone. EPA performed separate acute risk assessments for
females 13-49 years old and for the general population, including
infants and children, based on different endpoints and aPADs. In
estimating acute dietary exposure, EPA used food consumption
information from the United States Department of Agriculture (USDA)
1994-1996 and 1998 Nationwide Continuing Surveys of Food Intake by
Individuals (CSFII). As to residue levels in food, EPA used tolerance-
level residues, Dietary Exposure Evaluation Model (DEEM)\TM\ (ver.
7.81) default processing factors, and assumed 100 percent crop treated
(PCT) for all commodities.
ii. Chronic exposure. In conducting the chronic dietary exposure
assessment EPA used the food consumption data from the USDA 1994-1996
and 1998 CSFII. As to residue levels in food, EPA used tolerance-level
residues, DEEM\TM\ (ver. 7.81) default processing factors, and assumed
100 PCT for all commodities.
iii. Cancer. Based on the data summarized in Unit III.A., EPA has
concluded that sulfentrazone does not pose a cancer risk to humans.
Therefore, a dietary exposure assessment for the purpose of assessing
cancer risk is unnecessary.
iv. Anticipated residue and PCT information. EPA did not use
anticipated residue and/or PCT information in the dietary assessment
for sulfentrazone. Tolerance level residues and/or 100 PCT were assumed
for all food commodities.
2. Dietary exposure from drinking water. The Agency used screening
level water exposure models in the dietary exposure analysis and risk
assessment for sulfentrazone in drinking water. These simulation models
take into account data on the physical, chemical, and fate/transport
characteristics of sulfentrazone. Further information regarding EPA
drinking water models used in pesticide exposure assessment can be
found at http://www.epa.gov/oppefed1/models/water/index.htm.
Sulfentrazone and 3-carboxylic acid sulfentrazone are the residues
of concern in drinking water. Therefore, the First Index Reservoir
Screening Tool (FIRST) model was used to estimate concentrations of
sulfentrazone and 3-carboxylic acid sulfentrazone in surface water, and
the Screening Concentration in Ground Water (SCI-GROW) model was
utilized to estimate concentrations in ground water. The estimated
drinking water concentrations (EDWCs) of sulfentrazone and 3-
carbyoxylic acid sulfentrazone for acute exposures are estimated to be
35.8 parts per billion (ppb) for surface water and 26.0 ppb for ground
water. For chronic exposures for non-cancer assessments, EDWCs are
estimated to be 7.8 ppb for surface water and 26.0 ppb for ground
water.
Modeled estimates of drinking water concentrations were directly
entered into the dietary exposure model. For acute dietary risk
assessment, the water concentration value of 35.8 ppb was used to
assess the contribution to drinking water. For chronic dietary risk
assessment, the water concentration of value 26.0 ppb was used to
assess the contribution to drinking water.
3. From non-dietary exposure. The term ``residential exposure'' is
used in this document to refer to non-occupational, non-dietary
exposure (e.g., for lawn and garden pest control, indoor pest control,
termiticides, and
[[Page 5708]]
flea and tick control on pets). Sulfentrazone is currently registered
for the following use that could result in residential exposures:
residential home lawns/turf and recreational turf, such as golf courses
(application by professional applicators only). EPA assessed
residential exposure using the following assumptions: Adults were
assessed for potential short-term dermal and inhalation handler
exposure from applying sulfentrazone to residential turf/home lawns and
for short-term postapplication dermal exposure from contact with
treated residential and recreational turf (home lawns and golf
courses). Youths, ages 10-12 years old, were selected as a
representative population to assess postapplication dermal exposure
from contact with treated residential and recreational turf (home lawns
and golf courses). Children, ages 3-6 years old, were selected as a
representative population to assess for postapplication dermal and
incidental oral (hand-to-mouth, object-to-mouth, soil ingestion and
episodic ingestion of granules) exposure to residential turf/home
lawns. As short- and intermediate-term points of departure are the
same, the short-term assessment is considered protective of
intermediate-term exposures. For children, however, while all three
incidental oral exposures were aggregated for short-term exposures, the
intermediate-term postapplication exposure scenario included only the
soil ingestion incidental oral pathway, as this is the only pathway
assumed to potentially result in intermediate-term exposures. Chronic
exposures are not expected and were not assessed.
Further information regarding EPA standard assumptions and generic
inputs for residential exposures may be found at http://www.epa.gov/pesticides/trac/science/trac6a05.pdf.
4. Cumulative effects from substances with a common mechanism of
toxicity. Section 408(b)(2)(D)(v) of FFDCA 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 has not found sulfentrazone to share a common mechanism of
toxicity with any other substances, and sulfentrazone does not appear
to produce a toxic metabolite produced by other substances. For the
purposes of this tolerance action, therefore, EPA has assumed that
sulfentrazone does not have 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 EPA's Web site at http://www.epa.gov/pesticides/cumulative.
D. Safety Factor for Infants and Children
1. In general. Section 408(b)(2)(C) of FFDCA provides that EPA
shall apply an additional tenfold (10x) margin of safety for infants
and children in the case of threshold effects to account for prenatal
and postnatal toxicity and the completeness of the database on toxicity
and exposure unless EPA determines based on reliable data that a
different margin of safety will be safe for infants and children. This
additional margin of safety is commonly referred to as the FQPA Safety
Factor (SF). In applying this provision, EPA either retains the default
value of 10x, or uses a different additional safety factor when
reliable data available to EPA support the choice of a different
factor.
2. Prenatal and postnatal sensitivity. There is evidence of
increased quantitative susceptibility following in utero exposure in
the oral and dermal rat developmental toxicity studies. Developmental
effects, including decreased fetal body weights and reduced/delayed
skeletal ossifications were observed at doses that were not maternally
toxic. In the 2-generation reproduction study in rats, offspring
effects such as decreased body weights and decreased litter survival
were observed at a slightly maternally toxic dose (slightly decreased
body weight gain), indicating possible slightly increased qualitative
susceptibility. Additionally, several dose-dependent effects were
observed in rat pups whose mothers were treated with sulfentrazone in a
published non-guideline rat developmental toxicity study.
3. Conclusion. EPA has determined that reliable data show the
safety of infants and children would be adequately protected if the
FQPA SF were reduced to 1X. That decision is based on the following
findings:
i. The toxicity database for sulfentrazone is complete except for
immunotoxicity testing. Recent changes to 40 CFR part 158 require
immunotoxicity testing (OPPTS Test Guideline 870.7800) for pesticide
registration. However, the existing data are sufficient for endpoint
selection for exposure/risk assessment scenarios, and for evaluation of
the requirements under the FQPA. The toxicology database for
sulfentrazone does not show any evidence of treatment-related effects
on the immune system; the overall weight of evidence is consistent with
this chemical being a PPO inhibitor resulting in disruption of heme
biosynthesis and subsequent effects on red blood cell dysfunction
(e.g., anemia). Unlike white blood cells (leukocytes) which are cells
of the immune system, red blood cells function to deliver oxygen to
body tissues and are not involved in eliciting an immune response.
Furthermore, there is no indication in the sulfentrazone database of
any effect on leukocyte counts (an indicator of immune function). Thus,
the overall weight of evidence indicates that this chemical does not
directly target the immune system. Sulfentrazone also does not belong
to a class of chemicals (e.g., the organotins, heavy metals, or
halogenated aromatic hydrocarbons) that would be expected to be
immunotoxic. Based on the above considerations, EPA does not believe
that conducting a functional immunotoxicity study will result in a
lower point of departure than that currently used for overall risk
assessment. Therefore, an additional database UF to account for
potential immunotoxicity does not need to be applied.
ii. The toxicity database for sulfentrazone does not trigger the
need for a developmental neurotoxicity (DNT) study. There are no
indications in any of the studies available that the nervous system is
a target for sulfentrazone. The FOB findings were very non-specific
signs of toxicity (perianal staining, colored tears) and motor activity
changes only occurred at higher doses following acute exposure with
rapid reversibility, also indicating general toxicity rather than
specific neurotoxicity. The lack of neuropathological findings further
supports the non-specific nature of the signs observed. In addition,
there is a literature DNT study available for sulfentrazone. The only
reliable effects seen in this study involved effects on physical and
reflex development, which are known to be affected by body weight.
Therefore, these effects are likely secondary to the effects (including
body weight deficits) reported in the 2-generation reproductive
toxicity study. EPA employed an independent statistical method to
evaluate the literature DNT in an effort to determine if these effects
were consistent with effects observed in other guideline studies at
these same dose levels. The results of that analysis indicate that the
results of the literature DNT study are consistent with what was
observed in the rat 2-generation
[[Page 5709]]
reproduction study and that the studies used for risk assessment (NOAEL
of 10 mg/kg/day from the developmental toxicity study in rat and the
NOAEL of 14 mg/kg/day from the 2-generation reproduction study), are
protective of the observations made at [gteqt]25 mg/kg/day in the
literature study for which a NOAEL was not attained. Based on the
weight of evidence, there is no uncertainty related to developmental
neurotoxicity.
iii. There is evidence of increased quantitative susceptibility
following in utero exposure in the oral and dermal developmental
toxicity studies in rats and possible evidence of slightly increased
qualitative susceptibility of offspring in the 2-generation rat
reproduction study. However, concern is low because clear NOAELs have
been identified for the effects noted in these studies and both of the
developmental toxicity studies have been chosen for endpoint selection,
thereby protecting the relevant human subpopulations from the noted
effects.
iv. There are no residual uncertainties identified in the exposure
databases. The dietary food exposure assessments were performed based
on 100 PCT and tolerance-level residues. EPA made conservative
(protective) assumptions in the ground and surface water modeling used
to assess exposure to sulfentrazone in drinking water. EPA used
similarly conservative assumptions to assess postapplication exposure
of children as well as incidental oral exposure of toddlers. These
assessments will not underestimate the exposure and risks posed by
sulfentrazone.
E. Aggregate Risks and Determination of Safety
EPA determines whether acute and chronic dietary pesticide
exposures are safe by comparing aggregate exposure estimates to the
aPAD and cPAD. For linear cancer risks, EPA calculates the lifetime
probability of acquiring cancer given the estimated aggregate exposure.
Short-, intermediate-, and chronic-term risks are evaluated by
comparing the estimated aggregate food, water, and residential exposure
to the appropriate PODs to ensure that an adequate MOE exists.
1. Acute risk. Using the exposure assumptions discussed in this
unit for acute exposure, the acute dietary exposure from food and water
to sulfentrazone will occupy <1% of the aPAD for the general
population, including infants and children. For females 13-49 years
old, the acute dietary exposure to sulfentrazone from food and water
will occupy 2.3% of the applicable aPAD chosen for that population
subgroup.
2. Chronic risk. Using the exposure assumptions described in this
unit for chronic exposure, EPA has concluded that chronic exposure to
sulfentrazone from food and water will utilize 3.6% of the cPAD for
children 1-2 years old, the population group receiving the greatest
exposure. Based on the explanation in Unit III.C.3., regarding
residential use patterns, chronic residential exposure to residues of
sulfentrazone is not expected.
3. Short- and intermediate-term risk. Short- and intermediate-term
aggregate exposure takes into account short- and intermediate-term
residential exposure plus chronic exposure to food and water
(considered to be a background exposure level). Sulfentrazone is
currently registered for uses that could result in short- and
intermediate-term residential exposure, and the Agency has determined
that it is appropriate to aggregate chronic exposure through food and
water with short- and intermediate-term residential exposures to
sulfentrazone.
Using the exposure assumptions described in this unit for short-
and intermediate-term exposures, EPA has concluded the combined short-
and intermediate-term food, water, and residential exposures result in
aggregate MOEs of 310 for the general U.S. population; 450 for children
1-2 years old for short-term exposures; and 590 for children 1-2 years
old for intermediate-term exposures. Because EPA's level of concern for
sulfentrazone is a MOE of 100 or below, these MOEs are not of concern.
4. Aggregate cancer risk for U.S. population. Based on the lack of
evidence of carcinogenicity in two adequate rodent carcinogenicity
studies, sulfentrazone is not expected to pose a cancer risk to humans.
5. Determination of safety. Based on these risk assessments, EPA
concludes that there is a reasonable certainty that no harm will result
to the general population, or to infants and children from aggregate
exposure to sulfentrazone residues.
IV. Other Considerations
A. Analytical Enforcement Methodology
Adequate enforcement methodology (gas chromatography (GC)) is
available to enforce the tolerance expression. The method has been
forwarded for inclusion in the Pesticides Analytical Manual, Volume II.
The method may be requested from: Chief, Analytical Chemistry Branch,
Environmental Science Center, 701 Mapes Rd., Ft. Meade, MD 20755-5350;
telephone number: (410) 305-2905; e-mail address:
[email protected].
B. International Residue Limits
In making its tolerance decisions, EPA seeks to harmonize U.S.
tolerances with international standards whenever possible, consistent
with U.S. food safety standards and agricultural practices. EPA
considers the international maximum residue limits (MRLs) established
by the Codex Alimentarius Commission (Codex), as required by FFDCA
section 408(b)(4). The Codex Alimentarius is a joint U.N. Food and
Agriculture Organization/World Health Organization food standards
program, and it is recognized as an international food safety
standards-setting organization in trade agreements to which the United
States is a party. EPA may establish a tolerance that is different from
a Codex MRL; however, FFDCA section 408(b)(4) requires that EPA explain
the reasons for departing from the Codex level. There are no Codex,
Canadian, or Mexican MRLs established for residues of sulfentrazone in
or on the subject commodities.
C. Response to Comments
EPA received one comment to the Notice of Filing that had an
objection to ``the manufacture or sale'' of sulfentrazone, citing the
cruelty of animal testing as the main source of opposition. The Agency
has received these same or similar comments from this commenter on
numerous previous occasions. Please refer to the Federal Register of 70
FR 1349 (January 7, 2005) and 70 FR 37683 (June 30, 2005) for the
Agency's previous responses to these and other similar comments.
D. Revisions to Petitioned-For Tolerances
Based upon review of the data supporting the petition, EPA revised
the proposed tolerances for the following commodities: Brassica, leafy
greens, subgroup 5B from 0.35 ppm to 0.40 ppm; melon, subgroup 9A from
0.10 ppm to 0.15 ppm; vegetable, fruiting, group 8 from 0.05 ppm to
0.15 ppm; okra from 0.05 ppm to 0.15 ppm; pea, succulent from 0.05 ppm
to 0.15 ppm; flax from 0.05 ppm to 0.15 ppm; and strawberry from 0.05
ppm to 0.15 ppm. EPA revised the tolerance levels based on analysis of
the residue field trial data using the Agency's Tolerance Spreadsheet
in accordance with the Agency's Guidance for Setting Pesticide
Tolerances Based on Field Trial Data.
Additionally, EPA was petitioned for tolerances on fruiting
vegetable group 8
[[Page 5710]]
and a separate tolerance on okra. In the Federal Register of December
8, 2010 (75 FR 76284) (FRL-8853-8), EPA issued a final rule that
revised the crop grouping regulations. As part of this action, EPA
expanded and revised the existing fruiting vegetable crop group 8.
Changes to crop group 8 included adding okra, cocona, African eggplant,
pea eggplant, scarlet eggplant, goji berry, garden huckleberry,
martynia, naranjilla, roselle, sunberry, bush tomato, currant tomato,
and tree tomato; creating subgroups; revising the representative
commodities; and naming the new crop group fruiting vegetable group 8-
10. EPA indicated in the December 8, 2010 final rule as well as the
earlier January 6, 2010 proposed rule (75 FR 807) (FRL-8801-2) that,
for existing petitions for which a Notice of Filing had been published,
the Agency would attempt to conform these petitions to the rule.
Therefore, consistent with this rule, EPA has assessed and is
establishing a tolerance on fruiting vegetable group 8-10.
Finally, the EPA has revised the tolerance expression to clarify
(1) that, as provided in FFDCA section 408(a)(3), the tolerance covers
metabolites and degradates of sulfentrazone not specifically mentioned;
and (2) that compliance with the specified tolerance levels is to be
determined by measuring only the specific compounds mentioned in the
tolerance expression.
V. Conclusion
Therefore, tolerances are established for residues of the combined
residues of free and conjugated forms of sulfentrazone (N-[2,4-
dichloro-5-[4-(difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-1H-1,2,4-
triazol-1-yl]phenyl]methanesulfonamide) and its metabolites HMS (N-
(2,4-dichloro-5-(4-(difluoromethyl)-4,5-dihydro-3-hydroxymethyl-5-oxo-
1H-1,2,4-triazol-1-yl)phenyl)methanesulfonamide) and DMS (N-(2,4-
dichloro-5-(4-(difluoromethyl)-4,5-dihydro-5-oxo-1H-1,2,4-triazol-1-
yl)phenyl)methanesulfonamide, in or on Brassica, head and stem,
subgroup 5A at 0.20 ppm; Brassica, leafy greens, subgroup 5B at 0.40
ppm; melon, subgroup 9A at 0.15 ppm; vegetable, fruiting, group 8-10 at
0.15 ppm; pea, succulent at 0.15 ppm; flax at 0.15 ppm; strawberry at
0.15 ppm; and vegetable, tuberous and corm, subgroup 1C at 0.15 ppm.
Additionally, this regulation deletes existing individual tolerances in
or on cabbage at 0.20 ppm and potato at 0.15 ppm, and further deletes
the time-limited tolerance for bean, succulent seed without pod (lima
bean and cowpea) at 0.1 ppm.
VI. Statutory and Executive Order Reviews
This final rule establishes tolerances under section 408(d) of
FFDCA 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). Because this final rule has been
exempted from review under Executive Order 12866, this final rule is
not subject to Executive Order 13211, entitled Actions Concerning
Regulations That Significantly Affect Energy Supply, Distribution, or
Use (66 FR 28355, May 22, 2001) or Executive Order 13045, entitled
Protection of Children from Environmental Health Risks and Safety Risks
(62 FR 19885, April 23, 1997). 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., nor does it require any
special considerations under Executive Order 12898, entitled Federal
Actions to Address Environmental Justice in Minority Populations and
Low-Income Populations (59 FR 7629, February 16, 1994).
Since tolerances and exemptions that are established on the basis
of a petition under section 408(d) of FFDCA, 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.
This final rule directly regulates growers, food processors, food
handlers, and food retailers, not States or tribes, nor does this
action alter the relationships or distribution of power and
responsibilities established by Congress in the preemption provisions
of section 408(n)(4) of FFDCA. As such, the Agency has determined that
this action will not have a substantial direct effect on States or
tribal governments, on the relationship between the national government
and the States or tribal governments, or on the distribution of power
and responsibilities among the various levels of government or between
the Federal Government and Indian tribes. Thus, the Agency has
determined that Executive Order 13132, entitled Federalism (64 FR
43255, August 10, 1999) and Executive Order 13175, entitled
Consultation and Coordination with Indian Tribal Governments (65 FR
67249, November 9, 2000) do not apply to this final rule. In addition,
this final rule does not impose any enforceable duty or contain any
unfunded mandate as described under Title II of the Unfunded Mandates
Reform Act of 1995 (UMRA) (Public Law 104-4).
This action does not involve any technical standards that would
require Agency consideration of voluntary consensus standards pursuant
to section 12(d) of the National Technology Transfer and Advancement
Act of 1995 (NTTAA), Public Law 104-113, section 12(d) (15 U.S.C. 272
note).
VII. Congressional Review Act
The Congressional Review Act, 5 U.S.C. 801 et seq., generally
provides that before a rule may take effect, the agency promulgating
the rule must submit a rule report 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 this final rule in the Federal
Register. This final 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: January 14, 2011.
Daniel J. Rosenblatt,
Acting Director, Registration Division, Office of Pesticide Programs.
Therefore, 40 CFR chapter I is amended as follows:
PART 180--[AMENDED]
0
1. The authority citation for part 180 continues to read as follows:
Authority: 21 U.S.C. 321(q), 346a and 371.
0
2. Section 180.498 is amended as follows:
0
i. Revise the introductory text of paragraph (a)(1);
0
ii. Revise the introductory text of paragraph (a)(2), remove the
entries for ``Cabbage'' and ``Potato'' and add commodities to the
table;
0
iii. Revise paragraph (b); and
0
iv. Revise the introductory text of paragraph (d), to read as follows:
Sec. 180.498 Sulfentrazone; tolerances for residues.
(a)(1) General. Tolerances are established for the combined
residues of the free and conjugated forms of sulfentrazone, including
its metabolites and degradates, in or on the commodities in the table
below. Compliance with the tolerance levels
[[Page 5711]]
specified below is to be determined by measuring only the sum of
sulfentrazone (N-[2,4-dichloro-5-[4-(difluoromethyl)-4,5-dihydro-3-
methyl-5-oxo-1H-1,2,4-triazol-1-yl]phenyl]methanesulfonamide) and its
metabolite HMS (N-(2,4-dichloro-5-(4-(difluoromethyl)-4,5-dihydro-3-
hydroxymethyl-5-oxo-1H-1,2,4-triazol-1-yl)phenyl)methanesulfonamide,
calculated as the stoichiometric equivalent of sulfentrazone in or on
the following commodities.
* * * * *
(2) Tolerances are established for the combined residues of the
free and conjugated forms of sulfentrazone, including its metabolites
and degradates, in or on the commodities in the table below. Compliance
with the tolerance levels specified below is to be determined by
measuring only the sum of sulfentrazone (N-[2,4-dichloro-5-[4-
(difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-1H-1,2,4-triazol-1-
yl]phenyl]methanesulfonamide) and its metabolites HMS (N-(2,4-dichloro-
5-(4-(difluoromethyl)-4,5-dihydro-3-hydroxymethyl-5-oxo-1H-1,2,4-
triazol-1-yl)phenyl)methanesulfonamide) and DMS (N-(2,4-dichloro-5-(4-
(difluoromethyl)-4,5-dihydro-5-oxo-1H-1,2,4-triazol-1-
yl)phenyl)methanesulfonamide, calculated as the stoichiometric
equivalent of sulfentrazone in or on the following commodities.
------------------------------------------------------------------------
Parts per
Commodity million
------------------------------------------------------------------------
* * * * *
Brassica, head and stem, subgroup 5A........................ 0.20
Brassica, leafy greens, subgroup 5B......................... 0.40
* * * * *
Flax........................................................ 0.15
* * * * *
Melon, subgroup 9A.......................................... 0.15
Pea, succulent.............................................. 0.15
* * * * *
Strawberry.................................................. 0.15
* * * * *
Vegetable, fruiting, group 8-10............................. 0.15
Vegetable, tuberous and corm, subgroup 1C................... 0.15
------------------------------------------------------------------------
(b) Section 18 emergency exemptions. Time-limited tolerances are
established for the combined residues of the free and conjugated forms
of sulfentrazone, including its metabolites and degradates, in
connection with use of the pesticide under section 18 emergency
exemptions granted by EPA. Compliance with the tolerance levels
specified below is to be determined by measuring only the sum of
sulfentrazone (N-[2,4-dichloro-5-[4-(difluoromethyl)-4,5-dihydro-3-
methyl-5-oxo-1H-1,2,4-triazol-1-yl]phenyl]methanesulfonamide) and its
metabolites HMS (N-(2,4-dichloro-5-(4-(difluoromethyl)-4,5-dihydro-3-
hydroxymethyl-5-oxo-1H-1,2,4-triazol-1-yl)phenyl)methanesulfonamide)
and DMS (N-(2,4-dichloro-5-(4-(difluoromethyl)-4,5-dihydro-5-oxo-1H-
1,2,4-triazol-1-yl)phenyl)methanesulfonamide, calculated as the
stoichiometric equivalent of sulfentrazone in or on the following
commodities. These tolerances expire and are revoked on the dates
specified in the following table.
------------------------------------------------------------------------
Parts per Expiration/
Commodity million revocation date
------------------------------------------------------------------------
Flax, seed........................ 0.20 12/31/13
Strawberry........................ 0.60 12/31/13
------------------------------------------------------------------------
* * * * *
(d) Indirect or inadvertent residues. Tolerances are established
for inadvertent and indirect combined residues of the free and
conjugated forms of sulfentrazone, including its metabolites and
degradates, in or on the commodities in the table below. Compliance
with the tolerance levels specified below is to be determined by
measuring only the sum of sulfentrazone (N-[2,4-dichloro-5-[4-
(difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-1H-1,2,4-triazol-1-
yl]phenyl]methanesulfonamide) and its metabolites HMS (N-(2,4-dichloro-
5-(4-(difluoromethyl)-4,5-dihydro-3-hydroxymethyl-5-oxo-1H-1,2,4-
triazol-1-yl)phenyl)methanesulfonamide) and DMS (N-(2,4-dichloro-5-(4-
(difluoromethyl)-4,5-dihydro-5-oxo-1H-1,2,4-triazol-1-
yl)phenyl)methanesulfonamide, calculated as the stoichiometric
equivalent of sulfentrazone in or on the following commodities when
present therein as a result of the application of sulfentrazone to
growing crops.
* * * * *
[FR Doc. 2011-1898 Filed 2-1-11; 8:45 am]
BILLING CODE 6560-50-P