FLUORIDE ACTION NETWORK PESTICIDE PROJECT
Return to FAN's Pesticide Homepage
Return to Sulfentrazone Index Page
Sulfentrazone. September 21, 1999.
Pesticide Tolerances for Emergency Exemptions. Final Rule.
Federal Register.
http://www.epa.gov/fedrgstr/EPA-PEST/1999/September/Day-21/p24509.htm
[Federal Register: September 21, 1999 (Volume 64, Number 182)]
[Rules and Regulations]
[Page 51060-51067]
>From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr21se99-7]
-----------------------------------------------------------------------
ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
[OPP-300903; FRL-6097-8]
RIN 2070-AB78
Sulfentrazone; Pesticide Tolerances for Emergency Exemptions
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: This regulation establishes a time-limited tolerance for
residues of N-[2,4-dichloro-5-[4-(difluoromethyl)-4,5-dihydro-3-methyl-
5-oxo-1H-1,2,4-triazol-1-yl] phenyl] methanesulfonamide in or on
sunflowers, lima beans, and cowpeas. This action is in response to
EPA's granting of an emergency exemption under section 18 of the
Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) authorizing
use of the pesticide on sunflowers, lima beans, and cowpeas. This
regulation establishes a maximum permissible level for residues of
sulfentrazone in these food commodities pursuant to section 408(l)(6)
of the Federal Food, Drug, and Cosmetic Act (FFDCA), as amended by the
Food Quality Protection Act of 1996 (FQPA). The tolerances will expire
and is revoked on December 30, 2000.
DATES: This regulation is effective September 21, 1999. Objections and
requests for hearings must be received by EPA on or before November 22,
1999.
ADDRESSES: Written objections and hearing requests, identified by the
docket control number [OPP-300903], 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
[[Page 51061]]
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-300903], 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 2 (CM #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@epa.gov. Copies of electronic 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
or ASCII file format. All copies of electronic objections and hearing
requests must be identified by the docket control number [OPP-300903].
No Confidential Business Information (CBI) should be submitted through
e-mail. Copies of electronic objections and hearing requests on this
rule may be filed online at many Federal Depository Libraries.
FOR FURTHER INFORMATION CONTACT: By mail: Jacqueline E. Gwaltney,
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: Rm. 278, CM #2,
1921 Jefferson Davis Hwy., Arlington, VA, (703) 305-6792,
gwaltney.jackie@epamail@epa.gov.
SUPPLEMENTARY INFORMATION: EPA, on its own initiative, pursuant to
section 408(l)(6) of the FFDCA, 21 U.S.C. 346a, is establishing a
tolerance for residues of the herbicide N-[2,4-dichloro-5-[4-
(difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-1H-1,2,4-triazol-1-y-l]
phenyl] methanesulfonamide, in or on sunflowers, lima bean, and cowpeas
at 0.1 part per million (ppm). This tolerance will expire and is
revoked on December 30, 2000. EPA will publish a document in the
Federal Register to remove the revoked tolerance from the Code of
Federal Regulations.
I. Background and Statutory Findings
The FQPA (Public Law 104-170) was signed into law August 3, 1996.
FQPA amends both the FFDCA, 21 U.S.C. 301 et seq., and the FIFRA, 7
U.S.C. 136 et seq. The FQPA amendments went into effect immediately.
Among other things, FQPA amends FFDCA to bring all EPA pesticide
tolerance-setting activities under a new section 408 with a new safety
standard and new procedures. These activities are described in this
preamble and discussed in greater detail in the final rule establishing
the time-limited tolerance associated with the emergency exemption for
use of propiconazole on sorghum (61 FR 58135, November 13, 1996) (FRL-
5572-9).
New 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. . . .''
Section 18 of FIFRA authorizes EPA to exempt any Federal or State
agency from any provision of FIFRA, if EPA determines that ``emergency
conditions exist which require such exemption.'' This provision was not
amended by FQPA. EPA has established regulations governing such
emergency exemptions in 40 CFR part 166.
Section 408(l)(6) of the FFDCA requires EPA to establish a time-
limited tolerance or exemption from the requirement for a tolerance for
pesticide chemical residues in food that will result from the use of a
pesticide under an emergency exemption granted by EPA under section 18
of FIFRA. Such tolerances can be established without providing notice
or period for public comment.
Because decisions on section 18-related tolerances must proceed
before EPA reaches closure on several policy issues relating to
interpretation and implementation of the FQPA, EPA does not intend for
its actions on such tolerances to set binding precedents for the
application of section 408 and the new safety standard to other
tolerances and exemptions.
II. Emergency Exemption for Sulfentrazone on Sunflowers, Lima
Beans, and Cowpeas and FFDCA Tolerances
North Dakota claims that there is an emergency situation regarding
herbicide resistant weeds, especially kochia that has seriously reduced
sunflower yields in all production systems. They also claimed that
reduced till and no-till farmers need an herbicide tool, such as
sulfentrazone, that does not need to be incorporated and will allow
efficient, cost-effective control of broadleaf weeds. Presently there
is no such tool available. North Dakota requested the use of
sulfentrazone in order to eliminate the emergency. EPA has authorized
under FIFRA section 18 the use of sulfentrazone on sunflowers for
control of kochia in North Dakota.
Tennessee claims that the hophorn beam coppperleaf has increased in
recent years, and has become such an overwhelming pest that entire
fields were abandoned in 1995. The fields in question constitute some
of the most fertile agricultural land in West Tennessee, an area where
farming and agriculturally-related businesses are the primary sources
of income. The registered alternative, does not provide effective
control for the entire season.
After having reviewed these submissions, EPA concurs that emergency
conditions exist for these States.
As part of its assessment of this emergency exemption, EPA assessed
the potential risks presented by residues of sulfentrazone in or on
sunflowers, lima beans, and cowpeas. In doing so, EPA considered the
safety standard in FFDCA section 408(b)(2), and EPA decided that the
necessary tolerance under FFDCA section 408(l)(6) would be consistent
with the safety standard and with FIFRA section 18. Consistent with the
need to move quickly on the emergency exemption in order to address an
urgent non-routine situation and to ensure that the resulting food is
safe and lawful, EPA is issuing this tolerance without notice and
opportunity for public comment under section 408(e), as provided in
section 408(l)(6). Although this tolerance will expire and is revoked
on December 30, 2000, under FFDCA section 408(l)(5), residues of the
pesticide not in excess of the amounts specified in the tolerance
remaining in or on sunflowers, lima beans, and cowpeas after that date
will not be unlawful, provided the pesticide is applied in a manner
that was lawful under FIFRA, and the residues do not exceed a level
that was authorized by this tolerance at the time
[[Page 51062]]
of that application. EPA will take action to revoke this tolerance
earlier if any experience with, scientific data on, or other relevant
information on this pesticide indicate that the residues are not safe.
Because these tolerances are being approved under emergency
conditions, EPA has not made any decisions about whether sulfentrazone
meets EPA's registration requirements for use on sunflowers, lima
beans, and cowpeas or whether a permanent tolerance for this use would
be appropriate. Under these circumstances, EPA does not believe that
this tolerance serves as a basis for registration of sulfentrazone by a
State for special local needs under FIFRA section 24(c). Nor does this
tolerance serve as the basis for any State other than North Dakota and
Tennessee to use this pesticide on this crop under section 18 of FIFRA
without following all provisions of EPA's regulations implementing
section 18 as identified in 40 CFR part 166. For additional information
regarding the emergency exemption for sulfentrazone, contact the
Agency's Registration Division at the address provided under the
``ADDRESSES'' section.
III. Aggregate Risk Assessment and Determination of Safety
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 (62 FR 62961, November 26, 1997) (FRL-5754-7).
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
sulfentrazone and to make a determination on aggregate exposure,
consistent with section 408(b)(2), for a time-limited tolerance for
combined residues or residues of N-[2,4-dichloro-5-[4-(difluoromethyl)-
4,5-dihydro-3-methyl-5-oxo-1H-1,2,4-triazol-1-y-l] phenyl]
methanesulfonamide on sunflowers at 0.1 ppm, and on bean, succulent
seed with pod (lima beans & cowpeas) at 0.1 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 sulfentrazone are
discussed in this unit.
B. Toxicological Endpoint
1. Acute toxicity. For the acute analysis, the EPA selected two
endpoints, one for the Females 13+ population subgroup and another for
the General population (including infants and children). For the
Females 13+ population subgroup, a Reference dose (RfD) of 0.10
milligrams/kilograms/day (mg/kg/day) from a no observable adverse
effect level (NOAEL) = 10.0 was established based on decreased fetal
weight and retarded skeletal development seen in a developmental rat
study at a lowest observable adverse effect level (LOAEL) of 25 mg/kg/
day. For the General population (including infants and children), an
RfD of 2.5 mg/kg/day (NOAEL = 250) was established from an acute
neurotoxicity study in rats. This endpoint is based upon increased
clinical signs (abdominal gripping, abdominogenital staining, and/or
reddish-brown staining under the cage), EPA findings, and decreased
motor activity (which were reversed by day 14 postdose) at a LOAEL of
750 mg/kg/day. An uncertainty factor (UF) of 100X was applied to
account for both interspecies extrapolation 10X and intraspecies
variability 10X.
2. Chronic toxicity. For the chronic analysis, the EPA selected an
RfD of 0.14 mg/kg/day (NOAEL = 14.0) based on significant toxic effects
observed primarily in the second generation animals in a 2-generation
rat reproduction study at a LOAEL of 33/44 mg/kg/day in males and
females, respectively. A UF of 100X was applied to account for both
interspecies extrapolation 10X and intraspecies variability 10X.
3. Carcinogenicity. The Agency determined that sulfentrazone should
be classified as a ``Group E'' chemical (not likely to be carcinogenic
to humans via relevant routes of exposure). This weight of the evidence
judgment was largely based on the absence of significant tumor
increases in two adequate rodent carcinogenicity studies.
C. Exposures and Risks
1. From food and feed uses. Tolerances have been established (40
CFR 180.498) for the combined residues of N-[2,4-dichloro-5-[4-
(difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-1H-1,2,4-triazol-1-yl]
phenyl] methanesulfonamide, in or on a variety of raw agricultural
commodities. Risk assessments were conducted by EPA to assess dietary
exposures and risks from sulfentrazone 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 1-day or single exposure. An acute dietary risk assessment is
required for sulfentrazone.
Since two endpoints were selected for risk assessment, the acute
dietary analyses were conducted for two main population subgroups, the
Females 13+ subgroup and the General population (including infants,
children, and adult males (excluding Females 13+)). The acute RfDs for
the Females 13+ subgroup and the General population are 0.10 mg/kg/day
and 2.5 mg/kg/day, respectively. The acute population adjusted doses
(aPADs) are 0.01 mg/kg/day (0.10 mg/kg/day <divide> 10 = 0.01 mg/kg/
day) and 0.25 mg/kg/day (2.5 mg/kg/day <divide> 10 = 0.25 mg/kg/day)
for the Females 13+ subgroup and the General population, respectively.
Separate Tier 1 acute dietary exposure analyses were performed
using tolerance level residues and 100% crop treated (CT) information.
Dietary exposures and associated acute risk for the Females 13+
population subgroup at the 95th percentile are shown in Table 1 below.
Table 1- Summary of Results of Acute DEEM Analysis for Sulfentrazone
(Females 13+)
------------------------------------------------------------------------
Subgroups Exposure (mg/kg/day) % aPAD
------------------------------------------------------------------------
Females (13+, pregnant, not 0.000515.......... 5.2
nursing).
Females (13+, nursing).......... 0.000702.......... 7.0
Females (13-19 years, not 0.000663.......... 6.6
pregnant, not nursing).
Females (20+ years, not 0.000501.......... 5.0
pregnant, not nursing).
Females (13-50 years)........... 0.000562.......... 5.6
------------------------------------------------------------------------
Dietary exposures and associated acute risk for the General
population including infants and children at the 95th percentile are
shown in Table 2 below. The other subgroups included in Table 2
represent the highest dietary exposures for their respective subgroups
(i.e., children and the other General population subgroups higher than
U.S. population).
[[Page 51063]]
Since the EPA determined to retain the factor of 10X, the PAD was
used in this risk assessment. The PAD is equal to the acute or chronic
RfD divided by the FQPA Safety Factor. Therefore, the Agency's level of
concern is for values >100% PAD.
Table 2. - Summary of Results of Acute DEEM Analysis for Sulfentrazone
(General Population Including Infants and Children)
------------------------------------------------------------------------
Subgroups Exposure (mg/kg/day) %aPAD
------------------------------------------------------------------------
U.S. Population (48 Contiguos 0.000901.......... <1
States).
Non-Hispanic Blacks............. 0.001016.......... <1
Non-nursing Infants (<1 year)... 0.001599.......... <1
Children (1-6 years)............ 0.001513.......... <1
------------------------------------------------------------------------
The %aPADs for the Females 13+ subgroup were <100%, and the highest
was 7.0% for Females (13+/nursing). The %aPADs for the General
population (including infants and children) were <100%, and the highest
subgroups (as shown in Table 3) had %aPADs of <1%. For acute dietary
risk, the Agency's level of concern is >100% aPAD. The results of the
acute analyses indicate that the acute dietary risks associated with
the existing and proposed uses of sulfentrazone are well below the
Agency's current level of concern.
ii. Chronic exposure and risk. A chronic dietary risk assessment is
required for sulfentrazone. The chronic RfD used for the chronic
dietary analysis for sulfentrazone is 0.14 mg/kg/day. Therefore, the
chronic population adjusted dose (cPAD) is 0.014 (0.14 mg/kg/day
<divide> 10 = 0.014 mg/kg/day) for chronic dietary exposure for All
Populations which include Infants and Children. The chronic dietary
exposure analysis used mean consumption (3-day average) data. A Tier 1
chronic dietary exposure assessment was performed using tolerance level
residues and 100% crop treated (CT) information for all commodities as
well. Since the Agency determined to retain the factor of 10X, the PAD
was used in this risk assessment. The PAD is equal to the acute or
chronic RfD divided by the FQPA Safety Factor. Therefore, the Agency's
level of concern is for values >100% PAD.
Chronic dietary exposures for the General population and other
subgroups are presented in Table 3 below. The other subgroups included
in Table 3 represent the highest dietary exposures for their respective
subgroups (i.e., children, females, and the other General population
subgroups higher than U.S. population).
Table 3. Summary of Results from Chronic DEEM Analysis of Sulfentrazone
------------------------------------------------------------------------
Subgroups Exposure (mg/kg/day) % cPAD
------------------------------------------------------------------------
U.S. Population (48 Contiguous 0.000343.......... 2.4
States).
Non-Hispanic Other Than Black or 0.000372.......... 2.7
White.
Non-nursing Infants (<1 year)... 0.000778.......... 5.6
Children (1-6 years)............ 0.000773.......... 5.5
Females (13+, not pregnant or 0.000318.......... 2.3
nursing).
Males (13-19 years)............. 0.000382.......... 2.7
------------------------------------------------------------------------
The %cPADs for all subgroups were <100%, and the highest was 5.6%
for non-nursing infants (<1 year) and children (1-6 years). The results
of the chronic analysis indicate that the chronic dietary risk
associated with the existing and proposed uses of sulfentrazone is well
below the Agency's current level of concern.
2. From drinking water. Drinking Water Level of Comparison (DWLOC)
is a theoretical upper limit on a pesticide's concentration in drinking
water in light of total aggregate exposure to a pesticide in food,
drinking water, and through residential uses. A DWLOC will vary
depending on the toxic endpoint, with drinking water consumption and
body weights. Different populations will have different DWLOCs.
The Agency uses DWLOCs internally in the risk assessment process as
a surrogate measure of potential exposure associated with pesticide
exposure through drinking water. In the absence of monitoring data for
pesticides, it is used as a point of comparison against conservative
model estimates of a pesticide's concentration in water.
DWLOC values are not regulatory standards for drinking water. They
do have an indirect regulatory impact through aggregate exposure and
risk assessments.
EPA does not have monitoring data available to perform a
quantitative drinking water risk assessment for sulfentrazone at this
time. Thus, ground and surface water exposure estimates were used for
sulfentrazone on sunflowers.
i. 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 (RfDs or acute dietary NOAELs) 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 sulfentrazone 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 sulfentrazone 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. Cumulative exposure to substances with a 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 sulfentrazone 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,
sulfentrazone 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 sulfentrazone has a common mechanism of
toxicity with other substances. For more 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).
[[Page 51064]]
D. Aggregate Risks and Determination of Safety for U.S. Population
1. Acute risk. Since there are no residential uses for
sulfentrazone, the aggregate exposure only includes food and water.
From the acute dietary (food only) risk assessments, high-end
exposure estimates were calculated for the two main subgroups, Females
13+ years and the General population. For the subgroup Females 13+, the
percentages of the aPAD that will be utilized by acute dietary (food
only) exposure to residues of sulfentrazone range from 5.7% for Females
(20+ yrs, not pregnant, not nursing) to 7.9% for Females (13+,
pregnant, not nursing). For the General population subgroup, which
includes the U.S. population and the most highly exposed subgroups
(non-Hispanic Blacks, non-nursing infants (<1 year), and children (1-6
years)), <1% of the aPAD is occupied by acute dietary food exposure.
The low %aPADs calculated for the Female 13+ subgroup and the General
population provide assurance that there is reasonable certainty that no
harm will be caused to infants, children, or adults from acute
aggregate exposure to sulfentrazone residues.
The maximum estimated concentrations of sulfentrazone in surface
and ground water are less than the Agency's DWLOCs for sulfentrazone as
a contribution to acute aggregate exposure. Therefore, OPP concludes
with reasonable certainty that residues of sulfentrazone in drinking
water do not contribute significantly to the acute aggregate human
health risk at the present time considering the present uses and the
uses proposed in this action.
The Agency bases this determination on a comparison of estimated
concentrations of sulfentrazone in surface waters and ground waters to
levels of comparison for sulfentrazone in drinking water. The estimates
of sulfentrazone in surface and ground waters are derived from water
quality models that use conservative assumptions regarding the
pesticide transport from the point of application to surface and ground
water. Because EPA considers the aggregate risk resulting from multiple
exposure pathways associated with a pesticide's uses, levels of
comparison in drinking water may vary as those uses change. If new uses
are added in the future, EPA will reassess the potential impacts of
sulfentrazone on drinking water as a part of the acute aggregate risk
assessment process.
2. Chronic risk. Since there are no residential uses for
sulfentrazone, the aggregate exposure only includes food and water.
For the U.S. population, 2% of the cPAD is occupied by dietary
(food) exposure. For the most highly exposed subgroups, non-nursing
infants (<1 year) and children (1-6 years), 6% of the cPAD is occupied
by dietary food exposure. The estimated average concentrations of
sulfentrazone in surface and ground water are less than EPA's levels of
comparison for sulfentrazone in drinking water as a contribution to
chronic aggregate exposure. Therefore, EPA concludes with reasonable
certainty that residues of sulfentrazone in drinking water do not
contribute significantly to the chronic aggregate human health risk at
the present time considering the present uses and uses proposed in this
action.
EPA bases this determination on a comparison of estimated
concentrations of sulfentrazone in surface waters and ground waters to
levels of comparison for sulfentrazone in drinking water. The estimates
of sulfentrazone in surface and ground waters are derived from water
quality models that use conservative assumptions regarding the
pesticide transport from the point of application to surface and ground
water. Because EPA considers the aggregate risk resulting from multiple
exposure pathways associated with a pesticide's uses, levels of
comparison in drinking water may vary as those uses change. If new uses
are added in the future, EPA will reassess the potential impacts of
sulfentrazone on drinking water as a part of the aggregate chronic risk
assessment process.
3. Short- and intermediate-term risk. Since there are no
residential uses or exposure scenarios, short- and intermediate-term
aggregate risk assessments were not conducted.
4. Aggregate cancer risk for U.S. population. Sulfentrazone has
been classified as a ``Group E'' chemical (not likely to be
carcinogenic to humans via relevant routes of exposure) by the RfD/Peer
Review Committee. Therefore, no cancer dietary exposure analysis was
performed.
5. 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 sulfentrazone 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 sulfentrazone, EPA considered data from
developmental toxicity studies in the rat and rabbit and a 2-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 during 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 prenatal and postnatal toxicity and
the completeness of the data base 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 MOE and uncertainty factor (usually 100 for
combined interspecies and intraspecies 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. Developmental toxicity studies -- a. Rats. In EPA's oral
developmental study in rats, the maternal (systemic) NOAEL was 25 mg/
kg/day, based on increased relative spleen weights and splenic
extramedullary hematopoiesis at the LOAEL of 50 mg/kg/day. The
developmental (fetal) NOAEL was 10 mg/kg/day, based on decreased mean
fetal weight and retardation in skeletal development as evidenced by
increased numbers of litters with any variation and by decreased
numbers of caudal vertebral and metacarpal ossification sites at the
LOEL of 25 mg/kg/day.
In the dermal developmental study in rats, the maternal (systemic)
NOAEL was <gr-thn-eq>250 mg/kg/day and a LOAEL was not determined. The
developmental (fetal) NOAEL was 100 mg/kg/day, based on decreased fetal
weight and increased fetal variations (hypoplastic or wavy ribs,
incompletely ossified lumbar vertebral arches, incompletely ossified
ischia or pubes, and reduced numbers of thoracic vertebral and rib
ossification sites) at the LOAEL of 250 mg/kg/day.
b. Rabbits. In the oral developmental toxicity study in rabbits,
the maternal
[[Page 51065]]
(systemic) NOAEL was 100 mg/kg/day, based on increased abortions,
clinical signs (decreased feces and hematuria), and reduced body weight
gain during gestation at the LOAEL of 250 mg/kg/day. The developmental
(pup) NOAEL was 100 mg/kg/day, based on increased resorptions,
decreased live fetuses per litter, and decreased fetal weight at the
LOAEL of 250 mg/kg/day.
iii. Reproductive toxicity study -- Rats. In the 2-generation
reproductive toxicity study in rats, the maternal (systemic) NOAEL was
14/16 mg/kg/day in males and females, respectively, based on decreased
maternal body weight and/or body weight gain during gestation in both P
and F1 generations, and reduced premating body weight gains in the
second generation (F1 adults) at the LOAEL of 33/40 mg/kg/day for males
and females, respectively. The developmental (pup) NOEL was 14/16 mg/
kg/day based on: (a) Reduced prenatal viability (fetal and litter); (b)
reduced litter size; (c) increased number of stillborn pups; (d)
reduced pup and litter postnatal survival and; (e) decreased pup body
weights throughout lactation at the LOAEL of 33/40 mg/kg/day. The
reproductive NOAEL was 14/16 mg/kg/day, based on: (a) Increased
duration of gestation in both F1 and F2 dams; (b) decreased fertility
in F1 generation (males); and/or (c) atrophy of the germinal epithelium
of the testes, oligospermia and intratubular degeneration of the
seminal product in the epididymis at the LOAEL of 33/40 mg/kg/day.
iv. Prenatal and postnatal sensitivity. The toxicological data base
for evaluating prenatal and postnatal toxicity for sulfentrazone is
complete with respect to current data requirements. Based on the
developmental and reproductive toxicity studies discussed above for
sulfentrazone there appears to be prenatal and postnatal sensitivity.
Based on the above, the Agency concludes that reliable data support use
of a 1,000-fold margin/factor, to protect infants and children.
v. Conclusion. There is a complete toxicity data base for
sulfentrazone and exposure data are complete or are estimated based on
data that reasonably accounts for potential exposures.
2. Acute risk. Acute RfD = 2.5 mg/kg/day. For acute dietary risk,
the Agency recommended use of the NOAEL of 250 mg/kg/day with an
uncertainty factor of 100, based on increased incidences of clinical
signs (abdominal gripping, abdominogenital staining, and or/reddish-
brown staining under the cage), EPA findings, and decreased motor
activity which were reversed by day 14 post dose at a LOAEL of 750 mg/
kg, from an acute neurotoxicity study in rats. There was no evidence of
neuropathology at the high dose (2,000 mg/kg).
3. Chronic risk. RfD = 0.14 mg/kg/day. For chronic dietary risk
assessment the Agency recommended use of the NOAEL of 14 mg/kg/day with
an uncertainty factor of 100, based on: (a) Decreased maternal body
weight and/or body weight gain during gestation in both P and F1
generations; (b) reduced premating body weight gains in the second
generation (F1 adults); (c) increased duration of gestation in both F1
and F2 dams; (d) reduced prenatal viability (fetal and litter); (e)
reduced litter size; (f) increased number of stillborn pups; (g)
reduced pup and litter postnatal survival; (h) decreased pup body
weights throughout lactation; (i) decreased fertility in F1 generation
males; and (j) atrophy of the germinal epithelium of the testes,
oligospermia and intratubular degeneration of the seminal product in
the epididymis at the LOAEL of 33/44 mg/kg/day for males and females,
respectively, from a 2-generation reproductive toxicity study in rats.
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 sulfentrazone
residues.
IV. Other Considerations
A. Metabolism in Plants and Animals
1. Plants. No plant metabolism study was submitted with this
petition. However, the nature of the residue in soybeans and rotational
crops is adequately understood. The residues of concern in soybeans are
the parent plus the metabolite 3-hydroxymethyl sulfentrazone. The
residues of concern in the rotational crops are the parent plus the
metabolites 3-hydroxymethyl sulfentrazone and 3-desmethyl
sulfentrazone.
EPA translated the sunflower plant metabolism data in support of
the use of sulfentrazone on lima beans and cowpeas. Due to the
uncertainty of the nature of the residue of sulfentrazone in lima beans
and cowpeas, the residues of concern will be the parent plus the
metabolites 3-hydroxymethyl sulfentrazone and 3-desmethyl
sulfentrazone.
2. Animals. There will be no animal feed items associated with the
proposed use provided that the label is modified to specify the
following restriction: Do not allow livestock to graze on treated
plants or feed treated plants or plant trash to livestock.
B. Analytical Enforcement Methodology
An analytical methodology for the determination of sulfentrazone,
3-desmethyl sulfentrazone, and 3-hydroxymethyl sulfentrazone residues
in/on various matrices was submitted with the petition. A petition
method validation (PMV) was successfully completed by Analytical
Chemistry Laboratory (ACL). The Limit of Quantitation (LOQ) and Minimum
Detection Limit (MDL) were determined to be 0.05 ppm and 0.005-0.025
ppm, respectively. EPA concluded that the method was suitable for
enforcement purposes.
Adequate enforcement methodology (example - gas chromotography) is
available to enforce the tolerance expression. 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, (703) 305-5229.
C. International Residue Limits
There are no Codex, Canadian or Mexican residue limits established
for sulfentrazone on lima beans and cowpeas. Therefore, no
compatibility problems exist for the tolerances.
D. Rotational Crop Restrictions
Rotational field trial data for wheat, corn, rice and sorghum were
submitted in support of a petition for a sulfentrazone tolerance on
soybeans. Permanent tolerances have been established on cereal grains
(excluding sweet corn) when planted in rotation with the primary crop
soybeans. The suggested rotational crop restrictions on the section 18
label pertaining to this petition are the same as those on the label
for soybeans. Therefore, additional rotational crop data are not
necessary for this action.
V. Conclusion
Therefore, the tolerance is established for combined residues of N-
[2,4-dichloro-5-[4-(difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-1H-
1,2,4-triazol-1-yl] phenyl] methanesulfonamide in sunflowers, lima
beans, and cowpeas at 0.1 ppm.
VI. 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
[[Page 51066]]
section 408(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 22, 1999, 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 under the ``ADDRESSES'' section (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 prescribed
by 40 CFR 180.33(i). EPA is authorized to waive any fee requirement
``when in the judgement of the Administrator such a waiver or refund is
equitable and not contrary to the purpose of this subsection.'' For
additional information regarding tolerance objection fee waivers,
contact James Tompkins, 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: Rm. 239, CM #2, 1921 Jefferson Davis Hwy., Arlington, VA,
(703) 305-5697, tompkins.jim@epa.gov. Requests for waiver of tolerance
objection fees should be sent to James Hollins, Information Resources
and Services Division (7502C), Office of Pesticide Programs,
Environmental Protection Agency, 401 M St., SW., Washington, DC 20460.
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 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.
VII. Public Record and Electronic Submissions
EPA has established a record for this regulation under docket
control number [OPP-300903] (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.
Objections and hearing requests may be sent by e-mail directly to
EPA at:
opp-docket@epa.gov
E-mailed objections and hearing requests must be submitted as an
ASCII file avoiding the use of special characters and any form of
encryption.
The official record for this regulation, as well as the public
version, as described in this unit 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 record which
will also include all comments submitted directly in writing. The
official record is the paper record maintained at the Virginia address
in ``ADDRESSES'' at the beginning of this document.
VIII. Regulatory Assessment Requirements
A. Certain Acts and Executive Orders
This final rule establishes a tolerance under section 408 of the
FFDCA. 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) (Public Law 104-4). Nor does it require any 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). 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).
In addition, since tolerances and exemptions that are established
on the basis of a petition under FFDCA section 408(l)(6), 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 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 the
Intergovernmental Partnership (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 provide to OMB a description of the extent of EPA's prior
consultation with representatives of affected State, local, and tribal
[[Page 51067]]
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 officials 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.
IX. 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 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 9, 1999.
James Jones,
Director, Registration Division, 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. 321(q), 346a and 371.
2. In Sec. 180.498, by revising the heading to paragraph (a);
redesignating the existing paragraph (b) as paragraph (d) and revising
the heading; adding a new paragraph (b); and adding and reserving
paragraph (c) to read as follows:
Sec. 180.498 Sulfentrazone; tolerances for residues.
(a) General. * * *
(b) Section 18 emergency exemptions. Time limited tolerances are
established for residues of the herbicide N-[2,4-dichloro-5-[4-
(difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-1H-1,2,4-triazol-1-y-l]
phenyl] methanesulfonamide, in connection with use of the pesticide
under section 18 emergency exemptions granted by EPA. The tolerance is
specified in the following table. The tolerances expire and will be
revoked by EPA on the date specified in the table.
------------------------------------------------------------------------
Expiration/
Commodity Parts per million revocation date
------------------------------------------------------------------------
Bean, succulent seed without pod 0.1 12/30/00
(lima beans & cowpeas).
Sunflower....................... 0.1 12/30/00
------------------------------------------------------------------------
(c) Tolerances with regional registrations. [Reserved]
(d) Indirect or inadvertent residues.
* * * * *
[FR Doc. 99-24509 Filed 9-20-99; 8:45 am]
BILLING CODE 6560-50-F