[Federal Register Volume 62, Number 46 (Monday, March 10, 1997)]
[Rules and Regulations]
[Pages 10703-10708]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-5874]


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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180

[OPP-300459; FRL-5591-9]
RIN AB-78


Sulfentrazone; Establishment of Tolerances

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This document establishes tolerances for 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 major metabolite 3-hydroxymethyl sulfentrazone (N-[2,4-
dichloro-5-[4-(difluoromethyl)-4,5-dihydro-3-hydroxymethyl-5-oxo-1H-
1,2,4-triazol-1-yl]phenyl]methanesulfonamide), in or on the raw 
agricultural commodity soybean seed at 0.05 ppm and for combined 
inadvertent residues of sulfentrazone, and its metabolites, 3-
hydroxymethyl sulfentrazone and 3-desmethyl sulfentrazone [N-[2,4-
dichloro-5-[4-(difluoromethyl)-4,5-dihydro-5-oxo-1H-1,2,4-triazol-l-
yl]phenyl]methanesulfonamide] in cereal grains (excluding sweet corn) 
forage at 0.2 ppm, straw at 0.6 ppm, hay at 0.2 ppm, grain at 0.1 ppm, 
stover at 0.1 ppm, bran at 0.15 ppm and hulls at 0.30 ppm. FMC 
Corporation submitted a petition to EPA under the Federal Food, Drug 
and Cosmetic Act as amended by the Food Quality Protection Act of l996 
(Pub. L. 104-170) requesting the tolerances.
EFFECTIVE DATE: This regulation becomes effective March 10, 1997.

ADDRESSES: Written objections and hearing requests, identified by the 
docket control number, [PF-670/OPP-300459], may be submitted to: 
Hearing Clerk (1900), Environmental Protection Agency, Rm. M3708, 401 M 
St., SW., Washington, DC 20460. Fees accompanying objections and 
hearing requests shall be labeled Tolerance Petition Fees and forwarded 
to: EPA Headquarters Accounting Operations Branch, OPP (Tolerance 
Fees), P.O. Box 360277M, Pittsburgh, PA 15251. A copy of any objections 
and hearing requests filed with the Hearing Clerk should be identified 
by the docket control number and submitted to: Public Response and 
Program Resources Branch, Field Operations Division (7506C), Office of 
Pesticide Programs, Environmental Protection Agency, 401 M St., SW., 
Washington, DC 20460. In person, bring copy of objections and hearing 
requests to: Rm. 1132, CM #2, 1921 Jefferson Davis Hwy., Arlington, VA 
22202. A copy of objections and hearing requests filed with the Hearing 
Clerk may also be submitted electronically to the OPP by sending 
electronic mail (e-mail) to: <a href="/cdn-cgi/l/email-protection#076877772a6368646c6273476277666a666e6b2962776629606871"><span class="__cf_email__" data-cfemail="375847471a5358545c5243775247565a565e5b1952475619505841">[email protected]</span></a>.
    Copies of objections and hearing requests must be submitted as an 
ASCII file avoiding the use of special characters and any form of 
encryption. Copies of objections and hearing requests will also be 
accepted on disks in WordPerfect 5.1 file format or ASCII file format. 
All copies of objections and hearing requests in electronic form must 
be identified by the docket control number PF-670/OPP-300459. No 
Confidential Business Information (CBI) should be submitted through e-
mail. Electronic copies of objections and hearing requests on this rule 
may be filed online at many Federal Depository Libraries.

FOR FURTHER INFORMATION CONTACT: By mail: Joanne I. Miller, Product 
Manager (PM) 23, Registration Division (7505C), Environmental 
Protection Agency, 401 M St., SW., Washington, DC 20460. Office 
location and telephone number: Rm. 237, CM #2, 1921 Jefferson Davis 
Hwy., Arlington, VA 22202, (703)-305-6224; e-mail: 
<a href="/cdn-cgi/l/email-protection#39545055555c4b1753565857575c795c495854585055175c4958175e564f"><span class="__cf_email__" data-cfemail="cba6a2a7a7aeb9e5a1a4aaa5a5ae8baebbaaa6aaa2a7e5aebbaae5aca4bd">[email protected]</span></a>.

SUPPLEMENTARY INFORMATION: In the Federal Register of November 6, 1996 
(60 FR 57420) (FRL-5571-4), EPA issued a notice pursuant to section 
408(d) of the Federal Food, Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 
346a(d), announcing the filing of a pesticide tolerance petition by FMC 
Corporation, 1735 Market Street, Philadelphia, PA 19103. The petition 
requested to amend 40 CFR part 180 by establishing a tolerance for 
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]methanesulfona- mide) in or on raw agricultural commodity 
soybean seed at 0.05 ppm and rotational crop tolerances in cereal 
grains from 0.1 to 0.5 ppm. There were no comments received in response 
to the notice of filing.
    The data submitted in the petition and other relevant material have 
been evaluated. The toxicology data listed below were considered in 
support of these tolerances.

I. Toxicological Profile

    1. A battery of acute toxicity studies placed technical 
sulfentrazone in Toxicity Categories III and IV. No evidence of 
sensitization was observed following dermal application in guinea pigs.
    2. A 90-day subchronic toxicity study was conducted in rats, with 
dietary intake levels of 0, 3.3, 6.7, 19.9, 65.8, 199.3, or 534.9 mg/
kg/day for males and 0, 4, 7.7, 23.1, 78.1, 230.5, or 404.3 milligrams/
kilograms/day (mg/kg/day) for females respectively. No Observed Effect 
Levels (NOELs) of 19.9 mg/kg/day in males and 23.1 mg/kg/day in females 
were based on clinical anemia.
    3. A 90-day subchronic feeding study was conducted in mice by 
dietary admix

[[Page 10704]]

at doses of 0, 10.3, 17.8, 60.0, 108.4, or 194.4 mg/kg/day for males 
and 0, 13.9, 29.0, 79.8, 143.6, or 257.0 mg/kg/day for females, 
respectively. NOELs of 60 mg/kg/day (males) and 79.8 mg/kg/day 
(females) were based on decreases in body weights and/or gains; 
decreased erythrocytes, hemoglobin and hematocrit values; and splenic 
microscopic pathology.
    4. In a 90-day subchronic feeding study in dogs administered by 
dietary admix at doses of 0, 10, 28, or 57 mg/kg/day for males and 0, 
10, 28, or 73 mg/kg/day for females, a NOEL of 28 mg/kg/day was 
determined for both males and females based on decreases in hemoglobin 
and hematocrit, elevated alkaline phosphatase levels, increased liver 
weights and microscopic liver as well as splenic changes.
    5. A 12-month feeding study in dogs was dosed at levels of 0.0, 
9.9, 24.9, or 61.2 mg/kg/day for male dogs and 0.0, 10.4, 29.6, or 61.9 
mg/kg/day for female dogs in the control through high-dose groups, 
respectively, with a NOEL of 24.9 mg/kg/day for males and 29.6 mg/kg/
day for females based on hematology effects and microscopic liver 
changes.
    6. An 18-month feeding/carcinogenicity study in mice was conducted 
with dietary intake of 0, 46.6, 93.9, 160.5, or 337.6 mg/kg/day for 
males and 0, 58.0, 116.9, 198.0, or 407.1 mg/kg/day for females. A NOEL 
of 93.9 mg/kg/day in males and 116.9 mg/kg/day in females was based on 
decreases in hemoglobin and hematocrit. There were no treatment-related 
increases in tumors of any kind observed at any dose level.
    7. In a 24-month chronic feeding/oncogenicity study in rats at 
dietary doses of 0, 24.3, 40.0, 82.8, or 123.5 mg/kg/day for males and 
0, 20.0, 36.4, 67.0, or 124.7 mg/kg/day for females, an overall NOEL of 
40.0 mg/kg/day in males and 36.4 mg/kg/day in females was based on 
hematology effects and reduced body weights. There was no evidence of 
an oncogenic response.
    8. A prenatal oral developmental toxicity study in the rat with 
dose levels at 25.0 or 50.0 mg/kg/day established a maternal NOEL of 25 
mg/kg/day based on decreased body weight gain, increased spleen weight, 
and microscopic changes in the spleen, and a fetal NOEL of 10 mg/kg/day 
was based on fetal death, reduced body weights, and alterations in 
skeletal development at higher doses.
    9. A supplemental oral developmental toxicity study conducted in 
rats at oral dose levels of 25.0 and 50.0 mg/kg/day to test for cardiac 
effects at the request of the EPA, did not reveal any significant 
effects on fetal cardiac development. The results of this study 
confirmed the maternal and fetal findings of the previously-conducted 
developmental study on sulfentrazone in rats and did not alter the 
study conclusions.
    10. In a dermal developmental study in the rat at doses of 0, 5, 
25, 50, 100 and 250 mg/kg/day, a maternal (systemic) No Observed 
Adverse Effect Level (NOAEL) was established at 250 mg/kg/day. 
Significant treatment-related increases in the fetal and litter 
incidences of incompletely ossified lumbar vertebral arches, 
hypoplastic or wavy ribs, and incompletely ossified or nonossified 
ischia or pubes occurred at the high-dose (250 mg/kg/day). An 
additional significant increase in the high-dose fetal incidence of 
variations in the sternebrae (incompletely ossified or unossified) was 
not judged to be treatment-related. At 250 mg/kg/day, the mean numbers 
of thoracic vertebral and rib ossification sites were significantly 
decreased, a high-dose effect of treatment with sulfentrazone 
consistent with the significant treatment-related hypoplasia observed 
in the skeletal evaluation of the ribs. Therefore, the developmental 
(fetal) Lowest Observed Effect Level (LOEL) is 250 mg/kg/day based on 
decreased fetal body weight; increased incidences of fetal variations: 
hypoplastic or wavy ribs, incompletely ossified lumbar vertebral 
arches, and incompletely ossified ischia or pubes; and reduced number 
of thoracic vertebral and rib ossification sites. The developmental 
(fetal) NOEL is 100 mg/kg/day.
    11. A developmental toxicity study in rabbits was conducted at 
gavage dose levels of 0, 100, 250, or 375 mg/kg/day. Treatment-related 
incidences of decreased feces and hematuria were noted at 250 mg/kg/day 
or greater. In addition, at the 375 mg/kg/day dose level, five rabbits 
aborted. Significant reductions in mean body weight change were 
observed for the dosing period (GD 7- 19) and for the study duration 
(GD 0-29, both before and after adjustment for gravid uterine weight) 
at the 250 and 375 mg/kg/day dose levels. Therefore, the maternal 
(systemic) LOEL is 250 mg/kg/day, based upon increased abortions, 
clinical signs (hematuria and decreased feces), and reduced body weight 
gain. The maternal (systemic) NOEL is 100 mg/kg/day. Skeletal 
evaluation in fetuses revealed dose- and treatment-related findings at 
the 375 mg/kg/day dose level. These included significant increases in 
both the fetal and litter incidences of fused caudal vertebrae (a 
malformation) and of partially fused nasal bones (a variation). In 
addition, at 375 mg/kg/day, significant treatment-related reductions in 
ossification site averages were observed for metacarpals and both fore- 
and hindpaw phalanges. Therefore, the developmental (fetal) LOEL is 250 
mg/kg/day, based upon increased resorptions, decreased live fetuses per 
litter, and decreased fetal weight. The developmental (fetal) NOEL is 
100 mg/kg/day.
    12. A two-generation reproduction study in the rat at dietary 
levels of 14, 33, or 46 mg/kg/day in males and 16, 40, or 56 mg/kg/day 
in females established a NOEL for systemic and reproductive/
developmental parameters of 14 mg/kg/day for males and 16 mg/kg/day for 
females. The LOEL for systemic and reproductive/development parameters 
was 33 mg/kg/day for males and 40 mg/kg/day for females. Systemic 
effects were comprised of decreased body weight gains, while 
reproductive/developmental effect at the LOEL included degeneration 
and/or atrophy in the testes, with epididymal sperm deficits, in the 
second (F1) generation males. Male fertility in the F1 generation was 
reduced at higher doses; litter size, pup survival, and pup body weight 
for both generations were also effected at higher doses.
    13. A supplemental two-generation rat reproduction study was 
conducted at dietary intake levels of 50, 100, 200, or 500 ppm with a 
NOEL for reproductive parameters of 200 ppm. This study confirmed the 
reproductive/developmental effects observed in the first two-generation 
reproductive toxicity study. It was the conclusion of the RfD/Peer 
Review Committee that, under the conditions of the studies reviewed, 
sulfentrazone caused developmental and reproductive toxicity. The 
results of these studies elicited a high level of concern by the 
Committee, since the developmental toxicity studies demonstrated 
embryo/fetal toxicity at treatment levels that were not maternally 
toxic, and significant toxic effects were observed primarily in the 
second generation animals of the reproduction study. Because these 
animals had been exposed to sulfentrazone in utero, the possibility 
that the observed reproductive toxicity resulted from a developmental 
and/or genotoxic mechanism was suggested.
    14. A reverse gene mutation assay (salmonella typhimurium) yielded 
negative results, both with and without metabolic activation.
    15. A mouse lymphoma forward gene mutation assay yielded negative 
results with equivocal results without activation.

[[Page 10705]]

    16. A mouse micronucleus assay test was negative following 
intraperitoneal injection of 340 mg/kg.
    17. In an acute neurotoxicity study in rats at gavage doses of 0, 
250, 750, or 2,000 mg/kg, a NOEL of 250 mg/kg and a LOEL of 750 mg/kg 
were based upon increased incidences of clinical signs, Functional 
Observation Battery (FOB) findings, and decreased motor activity which 
were reversed by day 14 post-dose. There was no evidence of 
neuropathology.
    18. A 90-day subchronic neurotoxicity study in the rat was 
conducted at dietary levels of 30, 150, or 265 mg/kg/day in males, and 
37, 180, or 292 mg/kg/day in females, with a NOEL of 30 mg/kg/day in 
males and 37 mg/kg/day in females. The LOEL was 150 mg/kg/day for males 
and 180 mg/kg/day for females based on increased incidences of clinical 
signs, decreased body weights, body weight gains, and food consumption 
in females and increased motor activity in females at week 13. There 
were no neurohistopathological effects on the peripheral or central 
nervous system.
    19. A metabolism study in rats indicated that approximately 84 to 
104% of the orally administered dose of sulfentrazone was excreted in 
the urine, and that the pooled urinary radioactivity consisted almost 
entirely of 3-hydroxymethyl sulfentrazone. Pooled fecal radioactivity 
showed that the major metabolite consisted of 3-hydroxymethyl-
sulfentrazone (1.26 to 2.55% of the administered dose). The proposed 
metabolic pathway appeared to be conversion of the parent compound 
mainly to 3-hydroxymethyl-sulfentrazone (excreted in urine and feces).

II. Aggregate Exposures

    1. Food and feed uses. The primary source for human exposure to 
sulfentrazone will be from ingestion of both raw and processed 
agricultural commodities from soybeans. A DRES chronic exposure 
analysis was performed using tolerance level residues and 100% crop 
treated information to estimate the Theoretical Maximum Residue 
Contribution (TMRC) for the general population and 22 subgroups. The 
chronic analysis showed that exposure from the proposed new tolerance, 
in/on soybeans, on cereal grains (excluding sweet corn), on bran of 
cereal grains, milk, eggs, and meat for children 1 to 6 years old (the 
subgroup with the highest exposure) would be 38.8% of the RfD. The 
exposure for the general U.S. population would be 16.7% of the RfD.
    The analysis for sulfentrazone is a worst case estimate of dietary 
exposure with all residues at tolerance level and 100 percent of the 
commodities assumed to be treated with sulfentrazone. Even without 
refinements, the chronic dietary risk exposure to sulfentrazone appears 
to be minimal for this petition.
    2. Potable water. A ground water exposure estimate for 
sulfentrazone is based on findings from a voluntary prospective ground 
water study conducted in a sandy (worst case) site in North Carolina. 
Although this single ground water monitoring study was incomplete, 
enough data were collected to confirm that sulfentrazone leaches 
substantially to ground water in areas with sandy soils. Sulfentrazone 
was found in ground water at concentrations as high as 37 parts per 
billion (ppb) in shallow wells and 19 ppb in deeper wells. Residues in 
shallow ground water were highly persistent and only slowly dissipated, 
with little change in concentrations over a 1-year period, at which 
time sampling was terminated. The use of 37 ppb in estimating dietary 
exposure through ground water represents the worst case. The worst case 
is based on soil type (sandy) and a limited population that would 
obtain their drinking water from wells in this type of soil. However, 
HED feels that due to sulfentrazone's mobility (Koc = 43; Kd = 0.2-0.8) 
and persistence (<nearly-eq>9 year half life), over time the worst case 
values may be approached in more typical ground water settings. Using 
37 ppb, the dietary exposure from potable water is 0.00105 mg/kg/day to 
adults and 0.0037 mg/kg/day for children 1 to 6 years old.
    3. Non-dietary uses. Since the petition for use of sulfentrazone is 
limited to commercial soybean production, no non-dietary exposures are 
expected for the general population.
    4. Cumulative exposure to substances with common mechanism of 
toxicity. Section 408(b)(2)(D)(v) requires that, when considering 
whether to establish, modify, or revoke a tolerance, the Agency 
consider ``available information'' concerning the cumulative effects of 
a particular pesticide's residues and ``other substances that have a 
common mechanism of toxicity.'' While the Agency has some information 
in its files that may turn out to be helpful in eventually determining 
whether a pesticide shares a common mechanism of toxicity with any 
other substances, EPA does not at this time have the capability to 
resolve the scientific issues concerning common mechanism of toxicity 
in a meaningful way. EPA is commencing a pilot process to study this 
issue further through the examination of particular classes of 
pesticides. The Agency hopes that the results of this pilot process 
will enable the Agency to apply common mechanism issues to its 
pesticide risk assessments. At present, however, the Agency does not 
know how to apply the information in its files concerning common 
mechanism issues to risk assessments, and therefore believes that in 
most cases there is no ``available information'' concerning common 
mechanism that can be scientifically applied to tolerance decisions. 
Where it is clear that a particular pesticide may share a significant 
common mechanism with other chemicals, or where it is clear that a 
pesticide does not share a common mechanism with other chemicals, a 
tolerance decision may be affected by common mechanism issues. The 
Agency expects that most tolerance decisions will fall into the area in 
between, where EPA cannot reasonably determine whether a pesticide does 
or does not share a common mechanism of toxicity with other chemicals 
(and, if so, how that common mechanism should be factored into a risk 
assessment). In such circumstances, the Agency will reach a tolerance 
decision based on the best, currently-available and usable information, 
without regard to common mechanism issues. However, the Agency will 
also revisit such decisions when the Agency determines how to apply 
common mechanism information to pesticide risk assessments.
    In the case of sulfentrazone, EPA has determined that it does not 
now have the capability to apply the information in its files to a 
resolution of common mechanism issues in a manner that would be useful 
in a risk assessment. This tolerance determination therefore does not 
take into account common mechanism issues. The Agency will reexamine 
the tolerances for sulfentrazone, if reexamination is appropriate, 
after the Agency has determined how to apply common mechanism issues to 
its pesticide risk assessments.

III. Determination of Safety for U.S. Population and Children

    1. The U.S. population. Based on a NOEL of 14 mg/kg/day body weight 
(bwt)/day from a two-generation rat reproduction study that 
demonstrated histopathological findings in testes and epididymides of 
second generation males as an endpoint, and using an uncertainty factor 
of 1,000, the Agency has determined a reference dose (RfD) of 0.014 mg/
kg bwt/day for this assessment of risk. The extra factor of 10 and the 
uncertainty factor of 1,000 is to provide

[[Page 10706]]

added protection for infants and children. Based on the available 
toxicity data and the available exposure data identified above, the 
proposed tolerances will utilize 16.7% of the RfD for the U.S. 
population. Including an estimated exposure of 37 ppb in potable water, 
and assuming the injection of two liters of water per day, the dietary 
exposure for the U.S. adult population is increased and utilizes 
approximately 25% of the RfD.
    2. Children (1 to 6 years old). Using the RfD of 0.014 mg/kg bwt/
day, as described above, and a Theoretical Maximum Residue Contribution 
(TMRC) of 0.005437 mg/kg bwt/day determined for children (1 to 6 years 
old), the proposed tolerances will utilize 38.8% of the RfD. Including 
an estimated exposure of 37 ppb in potable water, and assuming the 
injection of 1 liter of water per day, the dietary exposure for 
children (1 to 6 years old) population is increased and utilizes 
approximately 65% of the RfD.
    3. Non-food uses. There are no non-food uses of sulfentrazone 
registered under the Federal Insecticide, Fungicide and Rodenticide 
Act, as amended.

IV. Determination of Safety for Infants and Children

    Risk to infants and children was determined by use of developmental 
toxicity studies in rats and a two-generation reproduction study in 
rats. The oral developmental toxicity studies resulted in a maternal 
NOEL of 25 mg/kg/day based on decreased body weight gain, increased 
spleen weight, and microscopic changes in the spleen, and a fetal NOEL 
of 10 mg/kg/day based on fetal death, reduced body weights, and 
alterations in skeletal development at higher doses. A dermal 
developmental toxicity study in rats resulted in a developmental 
(fetal) NOEL of 100 mg/kg/day based on decreased fetal body weight and 
increased incidences of fetal alterations, comprised primarily of 
skeletal variations and reductions in mean numbers of ossification 
sites. A two-generation reproduction study in rats resulted in a NOEL 
for systemic and reproductive/developmental parameters of 14 mg/kg/day 
for males and 16 mg/kg/day for females. The LOEL for systemic and 
reproductive/development parameters was 33 mg/kg/day for males and 40 
mg/kg/day for females. Systemic effects were comprised of decreased 
body weight gains, and reproductive/developmental effects at the LOEL 
included degeneration and/or atrophy of the testes, with epididymal 
sperm deficits in the second (F1) generation males. Male fertility in 
the F1 generation was reduced at higher doses; litter size, pup 
survival and pup body weight for both generations were also effected at 
higher doses.
    FFDCA section 408 provides that EPA shall apply an additional 
safety factor for infants and children in the case of threshold effects 
to account for pre- and post-natal toxicity and the completeness of the 
data base, unless EPA determines that such an additional factor is not 
necessary to protect the safety of infants and children. Based on 
current data requirements, the data base relative to pre- and post-
natal toxicity is complete. EPA has determined that the toxicology data 
profile for sulfentrazone contains clear, unequivocal evidence that 
this chemical causes developmental and reproductive toxicity. Based 
upon the available data and toxicity profile, the Agency RfD Peer 
Review Committee considered sulfentrazone to be a relatively potent 
reproductive/developmental toxicant, and determined that an additional 
10-fold uncertainty factor for the protection of infants and children 
was warranted.
    This decision was based upon the data described above. The 
following facts were considered in reaching this conclusion:
    (1) The lowest NOEL for chronic exposure, which is used to 
determine the RfD, is based upon severe, irreversible reproductive/
developmental effects, observed in the two-generation reproduction 
study in rats.
    (2) Developmental toxicity was observed in the absence of maternal 
effects in the prenatal developmental toxicity studies in rats 
(developmental NOELs were lower than maternal NOELs). This apparent 
increased sensitivity of the fetuses occurred following administration 
of sulfentrazone by either the dermal or the oral route, both of which 
are relevant to human exposure.
    (3) A steep dose-response curve exists for the reproductive and 
developmental endpoints of concern. The reproductive and/or 
developmental LOELs for the prenatal developmental toxicity studies in 
rats and the two-generation reproduction study are only approximately 
2.5 times greater than the corresponding NOELs in each of these 
studies. The reproductive and developmental NOELs are extremely low 
(i.e., in the range of 10 to 13 mg/kg/day). Additionally, in the rat 
prenatal developmental toxicity and two-generation reproduction 
studies, the reproductive/developmental effects increase in incidence 
and/or severity at higher doses.
    (4) The reproductive/developmental toxicity profile is consistent 
and reproducible, providing a large measure of confidence in the 
endpoints and dose levels.
    The percent of the RfD that will be utilized by the aggregate 
exposure to sulfentrazone for the most exposed subgroup would be 65% 
for children (1 to 6 years old) Therefore, EPA concludes that there is 
a reasonable certainty that no harm will result to infants and children 
from aggregate exposure.

V. Other Considerations

    1. Endocrine effects. An evaluation of the potential effects on the 
endocrine systems of mammals has not been determined; however, no 
evidence of such effects were reported in the chronic or reproductive 
toxicology studies described above. There was no observed pathology of 
the endocrine organs in these studies. There is no evidence at this 
time that sulfentrazone causes endocrine effects.
    2. Metabolism in plants and animals. The metabolism of 
sulfentrazone in plants and animals is adequately understood for the 
purposes of these tolerances. Crop residues found after the pre-
emergence use were the major metabolites 3-hydroxymethyl sulfentrazone 
and 3-desmethyl sulfentrazone. In rotational crops, sulfentrazone is 
metabolized via four different pathways: (i) Oxidation of the 3-methyl 
group to form 3-hydroxymethyl sulfentrazone, followed by further 
oxidation to form sulfentrazone carboxylic acid which is decarboxylated 
to 3-desmethyl sulfentrazone; (ii) hydrolysis of the trifluoromethyl 
group to form desdifluoromethyl sulfentrazone which is oxidized and 
decarboxylated to form desdifluoromethyl desmethyl sulfentrazone; (iii) 
hydrolysis of the sulfonamide group to form desmethylsulfonyl 
sulfentrazone; and (iv) scission of the phenyl and triazole rings to 
produce methyl triazole. The corresponding phenyl metabolites are 
believed to remain bound. In animal metabolism sulfentrazone per se was 
the predominant component of the residue. The metabolite 3-
hydroxymethyl sulfentrazone was also identified. It was determined by 
EPA that a soybean tolerance based on the parent and 3-hydroxymethyl 
sulfentrazone is therefore appropriate.
    3. Analytical method. There is a practical analytical method for 
detecting and measuring levels of sulfentrazone and its metabolites in 
or on food with a limit of detection that allows monitoring of food 
with residues at or above the levels set in these tolerances. The 
proposed analytical method for determining residues is hydrolysis

[[Page 10707]]

followed by gas chromatographic separation. EPA will provide 
information on this method to the Food and Drug Administration. Because 
of the long lead time from establishing these tolerances to publication 
the enforcement methodology is being made available in the interim to 
anyone interested in pesticide enforcement when requested by mail from: 
Calvin Furlow, Public Response Branch, Field Operations Division 
(7506C), Office of Pesticide Programs, Environmental Protection Agency, 
401 M St., SW., Washington, DC 20460. Office location and telephone 
number: Rm. 1130A, CM #2, 1921 Jefferson Davis Highway, Arlington, VA 
22202, (703) 305-5937.
    4. International tolerances. There are no Codex Alimentarius 
Commission (Codex) Maximum Residue Levels (MRLs) for sulfentrazone.
    5. Data Gaps. Data gaps currently exist for a 21-day dermal study 
in rabbits, in vivo cytogenetics dominant lethal assay in rats, a wheat 
processing study, additional rice field trials and residue data for 
sorghum aspirated grain fractions. Based on the toxicological data and 
the levels of exposure, EPA has determined that the proposed tolerances 
will be safe.

VI. Summary of Findings

    The analysis for sulfentrazone using tolerance level residues shows 
the proposed uses on soybeans will not cause exposure to exceed the 
levels at which the Agency believes there is an appreciable risk. All 
population subgroups examined by EPA are exposed to sulfentrazone 
residues at levels below 100% of the RfD for chronic effects.
    Based on the information cited above, the Agency has determined 
that the establishment of the tolerances by adding a new section to 40 
CFR part 180 will be safe; therefore, the tolerances are established as 
set forth below.

VII. Objections and Hearing Requests

    The new FFDCA section 408(g) provides essentially the same process 
for persons to ``object'' to a tolerance regulation issued by EPA under 
new section 408(e) and (1)(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 governs 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 May 9, 1997, file written objections to any 
aspect of this regulation (including the automatic revocation 
provision) and may also request a hearing on those objections. 
Objections and hearing requests must be filed with the Hearing Clerk, 
at the address given above (40 CFR 178.20). A copy of the objections 
and/or hearing requests filed with the Hearing Clerk should be 
submitted to the OPP docket for this rulemaking. The objections 
submitted must specify the provisions of the regulation deemed 
objectionable and the grounds for the objections (40 CFR 178.25). Each 
objection must be accompanied by the fee prescribed by 40 CFR 
180.33(i). If a hearing is requested, the objections must include a 
statement of the factual issue(s) on which a hearing is requested, the 
requestor's contentions on such issues, and a summary of any evidence 
relied upon by the objector (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 a 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 issue(s) in the manner sought by the requestor would be 
adequate to justify the action requested (40 CFR 178.32). Information 
submitted in connection with an objection or hearing request may be 
claimed confidential by marking any part or all of that information as 
Confidential Business Information (CBI). Information so marked will not 
be disclosed except in accordance with procedures set forth in 40 CFR 
part 2. A copy of the information that does not contain CBI must be 
submitted for inclusion in the public record. Information not marked 
confidential may be disclosed publicly by EPA without prior notice.

VIII. Public Docket

    A record has been established for this rulemaking under docket 
control number PF-670/OPP-300459. A public version of this record, 
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. 1132 of the Public 
Response and Program Resources Branch, Field Operation Division 
(7506C), Office of Pesticide Programs, Environmental Protection Agency, 
Crystal Mall #2, 1921 Jefferson Davis Highway, Arlington, VA. EPA has 
also established a special record for post-FQPA tolerances which 
contains documents of general applicability. This record can be found 
in the same location.
    The official record for this rulemaking, as well as the public 
version, as described above, is kept in paper form. Accordingly, in the 
event there are objections and hearing requests, EPA will transfer any 
copies of objections and hearing requests received electronically into 
printed, paper form as they are received and will place the paper 
copies in the official rulemaking record. The official rulemaking 
record is the paper record maintained at the address in ``ADDRESSES'' 
at the beginning of this document.

IX. Regulatory Assessment Requirements

    Under Executive Order 12866 (58 FR 51735, Oct. 4, 1993), this 
action is not a ``significant regulatory action'' and since this action 
does not impose any information collection requirements subject to 
approval under the Paperwork Reduction Act, 44 U.S.C. 3501 et seq., it 
is not subject to review by the Office of Management and Budget. In 
addition, this action does not impose any enforceable duty, or contain 
any ``unfunded mandates'' as described in Title II of the Unfunded 
Mandates Reform Act of 1995 (Pub. L. 104-4), or require prior 
consultation as specified by Executive Order 12875 (58 FR 58093, 
October 28, l993), or special considerations as required by Executive 
Order 12898 (59 FR 7629, February 16, l994).
    Because tolerances established on the basis of a petition under 
section 408(d) of FFDCA do not require issuance of a proposed rule, the 
regulatory flexibility analysis requirements of the Regulatory 
Flexibility Act (RFA), 5 U.S.C. 604(a), do not apply. Prior to the 
recent amendment of the FFDCA, EPA had treated such rulemakings as 
subject to the RFA; however, the amendments to the FFDCA clarify that 
no proposal is required for such rulemakings and hence that the RFA is 
inapplicable.
    Pursuant to 5 U.S.C. 801(a)(1)(A), EPA submitted 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 
General Accounting Office prior to publication of the rule in today's 
Federal Register. This rule is not a major rule as defined by 5 U.S.C. 
804(2).

[[Page 10708]]

List of Subjects in 40 CFR Part 180

    Environmental protection, Administrative practice and procedure, 
Agricultural commodities, Pesticides and pests, Reporting and 
recordkeeping requirements.

    Dated: February 27, 1997.
Daniel M. Barolo,
Director, Office of Pesticide Programs.
    Therefore, 40 CFR part 180 is amended as follows:

PART 180--[AMENDED]

    1. The authority citation for part 180 continues to read as 
follows:

    Authority: 21 U.S.C. 346a and 371.
    2. By adding Sec. 180.498 to read as follows:


Sec. 180.498   Sulfentrazone; tolerances for residues.

    (a) Tolerance--general. A tolerance is established for combined 
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 major metabolite 3-hydroxymethyl 
sulfentrazone N-[2,4-dichloro-5-[4-(difluoromethyl)-4,5-dihydro-3-
hydroxymethyl-5-oxo-1H-1,2,4-triazol-1-yl]phenyl]methanesulfonamide in 
or on the following raw agricultural commodity:

                                                                        
------------------------------------------------------------------------
                                                              Parts per 
                         Commodity                             million  
------------------------------------------------------------------------
Soybean, seed..............................................         0.05
------------------------------------------------------------------------

    (b) Tolerances--inadvertent and indirect residues. Tolerances are 
established for inadvertent and indirect combined 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 3-hydroxymethyl sulfentrazone (N-[2,4-dichloro-5-
[4-(difluoromethyl)-4,5-dihydro-3-hydroxymethyl-5-oxo-1H-1,2,4-triazol-
1-yl]phenyl]methanesulfonamide) and 3-desmethyl sulfentrazone (N-[2,4-
dichloro-5-[4-(difluoromethyl)-4,5-dihydro-5-oxo-1H-1,2,4-triazol-l-
yl]phenyl]methanesulfonamide) in or on the following raw agricultural 
commodities when present therein as a result of the application of 
sulfentrazone to growing crops.

                                                                        
------------------------------------------------------------------------
                                                              Parts per 
                         Commodity                             million  
------------------------------------------------------------------------
Cereal Grains (excluding sweet corn), Bran.................         0.15
Cereal Grains (excluding sweet corn), Forage...............          0.2
Cereal Grains (excluding sweet corn), Grain................          0.1
Cereal Grains (excluding sweet corn), Hay..................          0.2
Cereal Grains (excluding sweet corn), Hulls................         0.30
Cereal Grains (excluding sweet corn), Stover...............          0.1
Cereal Grains (excluding sweet corn), Straw................          0.6
------------------------------------------------------------------------


[FR Doc. 97-5874 Filed 3-7-97; 8:45 am]
BILLING CODE 6560-50-F


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