[Federal Register Volume 64, Number 91 (Wednesday, May 12, 1999)]
[Rules and Regulations]
[Pages 25439-25448]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-11835]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[OPP-300854; FRL-6078-5]
RIN 2070-AB78


Halosulfuron; Pesticide Tolerance

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This regulation establishes tolerances for residues of methyl-
5-[((4,6-dimethoxy-2-pyrimidinyl) amino]carbonylaminosulfonyl-3-chloro-
1-1H-pyrazole- 4-carboxylate in or on almond, hulls; corn, sweet, 
kernel + cob with husks removed; corn, sweet, forage; corn, sweet, 
fodder, corn, pop, grain; corn, pop, fodder; cotton, undelinted seed; 
cotton, gin by-products, pistachio, nutmeat; rice, grain; rice, straw; 
sugarcane, cane; and tree-nuts (crop group 14), nutmeat. This 
regulation also reduces tolerances for corn, field, grain; corn, field, 
forage; corn, field, fodder; sorghum, grain, grain; sorghum, grain, 
forage and sorghum, grain, fodder/stover. This regulation also deletes 
tolerances for soybean, seed soybean, forage; soybean, hay; wheat, 
grain; wheat, forage; and wheat, straw. Monsanto Company requested 
these tolerances under the Federal Food, Drug, and Cosmetic Act, as 
amended by the Food Quality Protection Act of 1996.

DATES: This regulation is effective May 12, 1999. Objections and 
requests for hearings must be received by EPA on or before July 12, 
1999.

ADDRESSES: Written objections and hearing requests, identified by the 
docket control number, [OPP-300854], must be submitted to: Hearing 
Clerk (1900), Environmental Protection Agency, Rm. M3708, 401 M St., 
SW., Washington, DC 20460. Fees accompanying objections and hearing 
requests shall be labeled ``Tolerance Petition Fees'' and forwarded to: 
EPA Headquarters Accounting Operations Branch, OPP (Tolerance Fees), 
P.O. Box 360277M, Pittsburgh, PA 15251. A copy of any objections and 
hearing requests filed with the Hearing Clerk identified by the docket 
control number, [OPP-300854], 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 be submitted electronically by sending electronic mail (e-
mail) to: [email protected]. Copies of objections and hearing requests 
must be submitted as an ASCII file avoiding the use of special 
characters and any form of encryption. Copies of objections and hearing 
requests will also be accepted on disks in WordPerfect 5.1/6.1 file 
format or ASCII file format. All copies of objections and hearing 
requests in electronic form must be identified by the docket control 
number [OPP-300854]. 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: Jim 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.J[email protected].

SUPPLEMENTARY INFORMATION: In the Federal Register of June 23, 1997 (62 
FR 33864) (FRL-5722-8) and May 29, 1998 (63 FR 29401) (FRL-5791-2), EPA 
issued notices pursuant to section 408 of the Federal Food, Drug, and 
Cosmetic Act (FFDCA), 21 U.S.C. 346a as amended by the Food Quality 
Protection Act of 1996 (FQPA) (Pub. L. 104-170) announcing the filing 
of a pesticide petition (PP) for tolerance by Monsanto Company, 700 
14th St., Suite 1100, Washington, DC 20005. This notice included a 
summary of the petition prepared by Monsanto Company, the registrant. 
There were no comments received in response to the notice of filing.
    The petition requested that 40 CFR 180.479 be amended by 
establishing tolerances for residues of the herbicide methyl 5-[(4,6-
dimethyloxy-2-pyrimidinyl)amino] carbonylaminosulfonyl-3-chloro-1-
methyl-1H-pyrazole-4-carboxylate in or on sugarcane, cane at 0.05 parts 
per million (ppm) (PP 6F4620) (62 FR 33864); sweet corn, (kernel plus 
cobs with husks removed at 0.1 ppm); sweet corn, forage at 0.5 ppm; 
sweet corn, fodder/stover at 1.5 ppm; popcorn, grain at 0.1 ppm; 
popcorn, fodder/stover at 1.5 ppm (PP 6F4661) (62 FR 33864).
    PP 8F4937 (63 FR 29401) proposed the establishment of tolerances 
for residues of methyl-5-[(4,6-dimethyloxy-2-pyrimidinyl) amino] 
carbonylaminosulfonyl-3-chloro-1-methyl- 1H-pyrazole-4- carboxylate in 
or on undelinted cotton seed and cotton gin by-products at 0.05 ppm, 
rice grain at 0.05 ppm, rice straw at 0.20 ppm, tree nut group (Group 
14) nutmeat at 0.05 ppm and hulls at 0.20 ppm, pistachio, nutmeat at 
0.05 ppm; and pistachio hulls at 0.2 ppm. The petition also proposed 
the establishment of tolerances for this chemical on corn, field, grain 
at 0.05 ppm; forage at 0.2; fodder at 0.8 ppm; sorghum, grain at 0.05 
ppm, sorghum, forage at 0.05 ppm, sorghum, fodder/stover at 0.1 ppm. 
The petition also requested the removal of indirect or inadvertent 
tolerance (40 CFR 180.479(b)), in or on the following raw agricultural 
commodities when present therein as a result of the application of 
halosulfuron-methyl to growing crops, soybean, forage at 0.5 ppm, 
soybean, hay at 0.5 ppm, soybean, seed at 0.5 ppm, wheat, forage at 0.1 
ppm, wheat, grain at 0.1 ppm and wheat, straw at 0.2 ppm.
    During the course of the review the Agency determined that the 
commodity tree nut hulls should be revised to read almond, hulls and 
that a tolerance for pistachio, hulls was not necessary as this 
commodity is not a significant livestock feed item. EPA also determined 
that the residue crop field data supported the establishment of 
tolerances for halosulfuron-methyl on corn, sweet, kernel + cob with 
husks removed at 0.05 ppm; corn, sweet, forage at 0.2 ppm corn, sweet, 
fodder at 0.8 ppm; corn, pop, grain at 0.05 ppm; and corn, pop, fodder 
at 0.8 ppm. This regulation is amended to reflect these revisions.

I. Background and Statutory Findings

    Section 408(b)(2)(A)(i) of the FFDCA allows EPA to establish a 
tolerance (the legal limit for a pesticide chemical

[[Page 25440]]

residue in or on a food) only if EPA determines that the tolerance is 
``safe.'' Section 408(b)(2)(A)(ii) defines ``safe'' to mean that 
``there is a reasonable certainty that no harm will result from 
aggregate exposure to the pesticide chemical residue, including all 
anticipated dietary exposures and all other exposures for which there 
is reliable information.'' This includes exposure through drinking 
water and in residential settings, but does not include occupational 
exposure. Section 408(b)(2)(C) requires EPA to give special 
consideration to exposure of infants and children to the pesticide 
chemical residue in establishing a tolerance and to ``ensure that there 
is a reasonable certainty that no harm will result to infants and 
children from aggregate exposure to the pesticide chemical residue.''
    EPA performs a number of analyses to determine the risks from 
aggregate exposure to pesticide residues. For further discussion of the 
regulatory requirements of section 408 and a complete description of 
the risk assessment process, see the final rule on Bifenthrin Pesticide 
Tolerances (62 FR 62961, November 26, 1997) (FRL-5754-7).

II. Aggregate Risk Assessment and Determination of Safety

    Consistent with section 408(b)(2)(D), EPA has reviewed the 
available scientific data and other relevant information in support of 
this action. EPA has sufficient data to assess the hazards of 
halosulfuron-methyl and to make a determination on aggregate exposure, 
consistent with section 408(b)(2), for a tolerance for residues of 
methyl 5-[(4,6-dimethoxy-2-pyrimidinyl)amino] carbonylaminosulfonyl]-3-
chloro-1-methyl-1H-pyrazole-4-carboxylate on sugarcane, cane at 0.05 
ppm, sweet corn (kernel plus cobs with husks removed) at 0.05 ppm, 
sweet corn forage at 0.2 ppm, sweet corn fodder/stover at 0.8 ppm, 
popcorn grain at 0.05 ppm and popcorn fodder/stover at 0.8 ppm, 
undelinted cotton seed at 0.05 ppm, cotton gin by-products at 0.05 ppm, 
rice, grain at 0.05 ppm, rice, straw at 0.20 ppm, tree nut group (crop 
group 14), nutmeat at 0.05 ppm, almond, hulls at 0.20 ppm, and 
pistachio, nutmeat at 0.05 ppm. The assessment will include currently 
established tolerances for residues of halosulfuron in or on field 
corn, grain at 0.05 ppm, field corn, forage at 0.2 ppm and field corn, 
fodder at 0.8 ppm, sorghum, grain at 0.05 ppm, sorghum, forage at 0.05 
ppm, sorghum, fodder/stover 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 halosulfuron-methyl 
are discussed in this unit.
    1. Acute toxicology studies place the technical-grade halosulfuron-
methyl in Toxicity Category III or IV for all routes of exposure. It is 
not a dermal sensitizer and essentially non-irritating to the skin.
    2. A 90-day feeding study in rats fed dosages of 7.4, 28.8, 116, 
and 497 milligrams/kilograms/day (mg/kg/day) for males and 8.9, 37.3, 
147, and 640 mg/kg/day for females and resulted in a lowest observed 
adverse effect level (LOAEL) of 497 mg/kg/day in males and 640 mg/kg/
day in females based on findings of decreased body weight gain, slight 
changes in several clinical chemistry parameters, and an increase in 
vacuolated livers and kidney tubular pigmentation, and a no observable 
adverse effect level (NOAEL) of 116 mg/kg/day in males and 147 mg/kg/
day in females.
    3. A 21-day dermal toxicity study in rats fed dosages of 0, 10, 
100, or 1,000 mg/kg/day resulted in a NOAEL of 100 mg/kg/day in males 
and 1,000 mg/kg/day in females. The only treatment-related effect was a 
decrease in body weight gain of the 1,000 mg/kg/day group in males.
    4. A 1-year chronic oral study in dogs fed dosages of 0, 0.25, 1.0, 
10.0, and 40.0 mg/kg/day resulted in a LOAEL of 40 mg/kg/day based on 
decreased weight gains and changes in hematological and blood chemistry 
parameters in females and a NOAEL of 10 mg/kg/day for systemic 
toxicity.
    5. A 78-week carcinogenicity study was performed on mice fed 
dosages of 0, 4.0, 41.1, 410.0, and 971.9 mg/kg/day (males) and 0, 5.2, 
51.0, 509.1, and 1,214.6 mg/kg/day (females). Males in the 971.6 mg/kg/
day group had decreased body weight gains and an increased incidence of 
microconcretion/mineralization in the testis and epididymis. No 
treatment-related effects were noted in females. Based on these 
results, a LOAEL of 971.9 mg/kg/day was established in males and NOAELs 
of 410 mg/kg/day in males and 1,214.6 mg/kg/day in females were 
established. The study showed no evidence of carcinogenicity.
    6. A combined chronic toxicity/carcinogenicity study in rats fed 
dosages of 0, 0.44, 4.4, 43.8, 108.3, and 225.2 mg/kg/day (males) and 
0, 0.56, 5.6, 53.6, and 138.6 mg/kg/day (females) resulted in a LOAEL 
of 225.2 mg/kg/day in males and 138.6 mg/kg/day in females based on 
decreased body weight gains, and a NOAEL of 108.3 mg/kg/day in males 
and 56.3 mg/kg/day in females. The study showed no evidence of 
carcinogenicity.
    7. A developmental toxicity study in rats fed dosages of 0, 75, 
250, and 750 mg/kg/day resulted in a developmental LOAEL of 750 mg/kg/
day based on decreases in mean litter size, increased number of 
resorptions, decreased mean fetal body weight, increases in fetal 
litter incidences of dilation of the lateral ventricles and other 
anaomalities in the developmental of the fetal nervous system, and 
skeletal variations such as anomalities or delays in ossificationin the 
thoracic vertebrae, sternebrae, and ribs, and a developmental NOAEL of 
250 mg/kg/day. The maternal LOAEL was 750 mg/kg/day based on increased 
incidence of clinical observations, reduced body weight gains, and 
reduced food consumption and food efficiency. The maternal NOAEL was 
250 mg/kg/day.
    8. A developmental toxicity study in rabbits fed dosages of 0, 15, 
50, and 150 mg/kg/day resulted in a developmental LOAEL of 150 mg/kg/
day, based on decreased mean litter size and increases in resorptions, 
and post-implantation loss, and a developmental NOAEL of 50 mg/kg/day. 
The maternal LOAEL was 150 mg/kg/day based on reduced body weight gain, 
reduced food consumption and food efficiency. The maternal NOAEL was 50 
mg/kg/day.
    9. A dietary 2-generation reproduction study in rats fed dosages of 
6.3, 50.4, and 223.2 (males) and 7.4, 58.7, and 261.4 mg/kg/day 
(females) through 1 breeding and 2 breedings of the offspring from the 
initial generation (7.4, 61.0, and 274,2 mg/kg/day for males and 8.9, 
69.7, and 319.9 mg/kg/day resulted in parental toxicity at 223.2 mg/kg/
day in males and 261.4 mg/kg/day in females in the form of decreased 
body weights, decreased body weight gains, and reduced food consumption 
during the premating period. Very slight effects were noted in body 
weights of the offspring at this dose. This effect was considered to be 
developmental toxicity (developmental delay) rather than a reproductive 
effect based on general parental systemic toxicity. No effects were 
noted on reproductive or other developmental toxicity

[[Page 25441]]

parameters. The systemic/developmental toxicity LOAEL was 223.2 mg/kg/
day in males and 261.4 mg/kg/day in females; the systemic/developmental 
toxicity NOAEL was 50.4 mg/kg/day in males and 58.7 mg/kg/day in 
females. The reproductive LOAEL was greater than 223.2 mg/kg/day in 
males and 261.4 mg/kg/day in females; the reproductive NOAEL was equal 
to or greater than 223.2 mg/kg/day in males and 261.4 mg/kg/day in 
females.
    10. Bacterial/mammalian microsomal mutagenicity assays were 
performed and found halosulfuron-methyl not to be mutagenic. Two 
mutagenicity studies were performed to test gene mutation and found to 
produce no chromosomal aberrations or gene mutations in cultured 
Chinese hamster ovary cells. An in vivo mouse micronucleus assay did 
not result in a significant increase in the frequency of micronucleated 
polychromatic erythrocytes in bone marrow cells. A mutagenicity study 
was performed on rats and unscheduled DNA synthesis was not induced in 
primary rat hepatocytes.
    11. In the rat metabolism study, parent compound absorption was 
rapid but incomplete. Excretion was relatively rapid at all doses 
tested with a majority of radioactivity eliminated in the urine and 
feces by 72 hours and appeared to be independent of dose and sex. Fecal 
elimination of parent was apparently the result of unabsorbed parent.
    12. The toxicology studies listed below were conducted with the 
metabolite, 3-chloro-1-methyl-5-sulfamoylpyrazole-4-carboxylic acid (3-
CSA). Based on the toxicological data of the 3-CSA metabolite, EPA 
concluded that the metabolites have lower toxicity compared to the 
parent compound and that it should not be included in the tolerance 
expression. The residue of concern is the parent compound only.
    i. A 90-day rat feeding study resulted in a LOAEL in males of 
>20,000 ppm and a NOAEL of 20,000 ppm (1,400 mg/kg/day). In females, 
the lowest effect level (LEL) is 10,000 ppm (772.8 mg/kg/day) based on 
decreased body weight gains and a NOAEL of 1,000 ppm (75.8 mg/kg/day).
    ii. A developmental toxicity resulted in a lowest observed effect 
level (LOEL) for maternal toxicity of >1,000 mg/kg/day based on the 
absence of systemic toxicity, a NOAEL of 1,000 mg/kg/day. The 
developmental LOEL is >1,000 mg/kg/day and the NOAEL is 1,000 mg/kg/
day.
    iii. The microbial reverse gene mutation did not produce any 
mutagenic effect while the mammalian cell gene mutation/Chinese hamster 
ovary cells did not show a clear evidence of mutagenic effect in the 
Chinese hamster ovary cells.
    iv. The mouse micronucleus assay did not show any clastogenic or 
aneugenic effect.

B. Toxicological Endpoints

    1. Acute toxicity. The acute dietary Reference Dose (RfD) of 0.5 
mg/kg/day is based on the rabbit developmental NOAEL of 50 mg/kg/day 
and should be used for assessing acute dietary risks for the sub-
populations, Females 13+ as well as Infants and Children. Although, the 
endpoint is developmental toxicity occurring in utero, and thus may not 
be suitable for use in risk assessment for Infants and Children, EPA 
determined that it is appropriate to use for this subpopulation 
(Infants and Children) because there is evidence of alteration to the 
development of the fetal nervous system in the developmental toxicity 
study in rats. Oral administration resulted in dilation of the lateral 
ventricles, dilation of the third ventricle, spinal cord agenesis, and 
adrenal agenesis at 750 mg/kg/day; and malformed brain cortex at 250 
mg/kg/day in rats only. Thus, EPA determined that potential effects on 
functional development mandate the use of this endpoint for females of 
child bearing age (Females 13+) as well as for infants and children.
    This endpoint is not applicable for adult males. A dose and 
endpoint was not identified for this subpopulation since no 
toxicological effects applicable to adult males and attributable to a 
single exposure (dose) were observed in oral toxicity studies including 
the developmental toxicity studies in rats and rabbits.
    2. Short- and intermediate-term toxicity. No short- or 
intermediate-term inhalation toxicity endpoints were identified. The 
Agency selected a short term dermal endpoint based on the rabbit oral 
developmental NOAEL of 50 mg/kg/day and a 75% dermal absorption factor 
instead of the 21-day dermal study because:
    i. There is a consistent pattern in the fetal effects (decreased 
mean litter size, increased number of resorptions, and increased 
postimplantation loss) observed in 2 species (rats and rabbits) via the 
oral route.
    ii. The developmental effects are considered acute effects and thus 
are appropriate for this exposure period of concern (i.e., 1-7 days).
    iii. The reproductive/fetal parameters are not evaluated in the 
dermal toxicity study, and thus the consequences of these effects 
cannot be ascertained for the dermal route of exposure.
    iv. This endpoint will provide adequate protection for the 
subpopulation Female 13+ (i.e., pregnant workers).
    Since an oral NOAEL was selected, a dermal absorption factor of 75% 
should be used for this dermal risk assessment. The Agency estimated a 
dermal absorption rate of 75% (i.e. a dermal:oral toxicity ratio of 
75%) based on the results of an oral developmental toxicity study and a 
21-day dermal toxicity study in the same species (rats). In the oral 
developmental toxicity study, the maternal NOAEL was 250 mg/kg/day and 
the LOAEL was 750 mg/kg/day based on decreases in body weight gains and 
food consumption. In the 21-day dermal toxicity study, the systemic 
toxicity NOAEL was 100 mg/kg/day and the LOAEL was 1,000 mg/kg/day 
based on decreased body weight gain in males. A ratio of the LOAELs 
from the oral and dermal studies, indicated an approximate dermal 
absorption rate of 75% (oral LOAEL of 750 mg/kg/day  dermal 
LOAEL of 1,000 mg/kg/day x 100 = 75%). This absorption factor may 
overestimate dermal absorption due to sensitivity differences in 
toxicity between the sexes (the developmental toxicity LOAEL is in 
females, and the 21-day dermal toxicity LOAEL is in males).
    The Agency selected the intermediate-term endpoint based on the 
chronic dog NOAEL of 10 mg/kg/day based on decreased body weight gains 
and changes in hematology and clinical chemistry parameters in females 
at the LOAEL of 40 mg/kg/day. At 40 mg/kg/day, decreases in body weight 
gain were seen during study weeks 0-13 in both sexes with the decrease 
being more pronounced in males (21%) than females (7%). Overall weight 
gain for the entire study (weeks 0-52) was not significantly affected 
in male dogs, but was decreased by 16% in female dogs at this dose. EPA 
selected this dose and endpoint for an intermediate-term risk 
assessment because the body weight anomalies, observed in both sexes 
during various phases of the study, meet the exposure period of concern 
(i.e., 1-week to several months). Since an oral NOAEL was selected, a 
dermal absorption factor of 75% should be used for this dermal risk 
assessment.
    3.  Chronic toxicity. EPA has established the RfD for halosulfuron-
methyl at 0.1 mg/kg/day. This RfD is based on the chronic dog NOAEL of 
10 mg/kg/day with decreased body weight gains and changes in clinical 
chemistry parameters in females at the LOAEL of 40 mg/kg/day.
    4. Carcinogenicity. There is no evidence of carcinogenicity in the

[[Page 25442]]

mouse or rat. On September 23, 1993, EPA tentatively classified 
halosulfuron-methyl as a Group E chemical based on the lack of evidence 
of carcinogenicity in male and female mice and rats. On February 26, 
1998, EPA classified halosulfuron-methyl as a Not Likely human 
carcinogen. There is an adequate mutagenicity data base that shows 
halosulfuron-methyl is not mutagenic.

 C. Exposures and Risks

    1. From food and feed uses. Tolerances have been established (40 
CFR 180.479) for the residues of methyl 5-[(4,6-dimethoxy-2-
pyrimidinyl) amino] carbonylaminosulfonyl-3-chloro-1-methyl-1H-
pyrazole-4- carboxylate, and its metabolites determined as 3-chloro-1-
methyl-5- sulfamoylpyrazole-4-carboxylic acid and expressed as the 
parent equivalents, in or on a variety of raw agricultural commodities. 
Tolerances are established on meat by products of cattle, goats, hogs, 
horses, and sheep at 0.1 ppm. Risk assessments were conducted by EPA to 
assess dietary exposures from halosulfuron methyl 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.
    The acute dietary RfD of 0.5 mg/kg/day is based on a developmental 
(rabbit) NOAEL of 50 mg/kg/day and an uncertainty factor of 100. The 
Agency has determined that a postnatal developmental neurotoxicity 
study in rats is required for halosulfuron-methyl based on the 
following weight-of-the-evidence considerations: In the developmental 
toxicity study in rats, there was evidence of alterations to the 
development of the fetal nervous system at 750 mg/kg/day (the highest 
dose tested), including dilation of the lateral ventricles (16 fetuses/
5 litters), dilation of the third ventricle (1/1), spinal cord agenesis 
(1/1), and adrenal agenesis (1/1) at the high dose; and malformed brain 
cortex (1/1) at 250 mg/kg/day. There was no evaluation of perfused 
nervous system tissues, since acute and subchronic neurotoxicity 
studies in rats were not required. The primary concern is the lack of 
information available in the data base that would allow the 
determination of whether functional deficits would be observed at dose 
levels below those which result in frank malformations of the central 
nervous system. Thus, Agency criteria require that a developmental 
neurotoxicity study be submitted.
    The 10x factor for protection of infants and children (as required 
by FQPA) should be removed for the following reasons: There was no 
indication of increased susceptibility of rats or rabbits to in utero 
and/or postnatal exposure to halosulfuron-methyl. In the prenatal 
developmental toxicity studies in rats and rabbits and the 2-generation 
reproduction study in rats, effects in the offspring were observed only 
at or above treatment levels which resulted in evidence of parental 
toxicity.
    The requirement of a developmental neurotoxicity study in rats did 
not warrant application of additional safety factors because: (a) The 
alterations observed in the fetal fetal nervous system occurred in only 
one species (in rats and not in rabbits); (b) the fetal effects which 
will be investigated in the required developmental neurotoxicity study 
were seen only at a dose of 750 mg/kg/day which is close to the limit-
dose (1,000 mg/kg/day); (c) there was no evidence of clinical signs of 
neurotoxicity, brain weight changes, or neuropathology in the 
subchronic or chronic studies in rats; (d) the developmental 
neurotoxicity study is required only as confirmatory data to understand 
what the effect is at a high exposure (dose) level; and (e) exposure 
assessments do not indicate a concern for potential risk to infants and 
children based on the results of the field trial studies and the very 
low application rate (equivalent to 0.06 lbs. active ingredient per 
acre). Detectable residues are not expected in human foods.
    A Dietary Exposure Evaluation Model (DEEM) analysis for 
halosulfuron-methyl was performed which incorporated proposed permanent 
tolerances for sweet corn, popcorn, tree nuts, pistachio, and rice; and 
the revised tolerances for field corn and grain sorghum. The analysis 
evaluates individual food consumption as reported by respondents in the 
USDA 1989-91 Continuing Survey of Food Intake by Individuals (CSFII) 
and accumulates exposure to the chemical for each commodity. Each 
analysis assumes uniform distribution of halosulfuron-methyl in the 
commodity supply. This Tier 1 analysis assumed tolerance-level residues 
for all commodities having halosulfuron-methyl tolerances and 100% of 
the associated crops received halosulfuron-methyl treatment. The 
Theoretical Maximum Residue Concentrations (TMRCs) resulting from these 
assumptions should be considered a very conservative estimate of the 
exposure. The acute dietary TMRC for the United States (U.S.) 
population is 0.000304 mg/kg/day or 0.06% of the RfD; 0.000754 or 0.15 
non-nursing infants (less than 1 year old and 0.000250 or 0.05% of the 
RfD for females (13-19 not pregnant/not nursing (np/nn). Refinement of 
the estimates through the use of percent-of-crop-treated data and 
anticipated residues will result in lower exposure estimates. Even with 
these conservative assumptions, the risks from both acute dietary (food 
only) exposure to halosulfuron-methyl are less than 1% for all 
population subgroups listed in the DEEM analysis. Therefore, the risk 
from acute ``food only'' exposure is below the Agency's level of 
concern (i.e.  100% of the acute RfD in the absence of 
additional safety factors, as is the case for halosulfuron-methyl).
    ii. Chronic exposure and risk. The chronic dietary RfD of 0.1 mg/
kg/day is based on the chronic dog study with a NOAEL of 10 mg/kg/day 
and an uncertainty factor of 100. As discussed above the 10x FQPA 
safety factor was removed.
    A DEEM analysis for halosulfuron-methyl was performed which 
incorporated proposed permanent tolerances for sweet corn, popcorn, 
tree nuts, pistachio, and rice; revised tolerances for field corn and 
grain sorghum; and revoked tolerances for wheat and soybean. The 
analysis evaluates individual food consumption as reported by 
respondents in the USDA 1989-91 Continuing Survey of Food Intake by 
Individuals (CSFII) and accumulates exposure to the chemical for each 
commodity. Each analysis assumes uniform distribution of halosulfuron-
methyl in the commodity supply. This Tier 1 analysis assumed tolerance-
level residues for all commodities having halosulfuron-methyl 
tolerances and 100% of the associated crops received halosulfuron-
methyl treatment. The TMRCs resulting from these assumptions should be 
considered a very conservative estimate of the exposure. The chronic 
TMRC for the U.S. population is 0.000102 mg/kg/day or 0.1% of the RfD; 
0.000158 mg/kg/day or 0.2 of the RfD for all infants (less than 1 year 
old); 0.000238 or 0.2% of the RfD for children (1-6); and 0.000100 mg/
kg/day or 0.1% of the RfD for females (13-19 years not pregnant or 
nursing). Refinement of the estimates through the use of percent-of-
crop-treated data and anticipated residues will result in lower 
exposure estimates. Even with these conservative assumptions, the risks 
from chronic dietary (food only) exposure to halosulfuron-methyl are 
less than 1% for all population subgroups listed in the DEEM analysis. 
Therefore, the risk from chronic ``food only'' exposure is below the 
Agency's level of concern (i.e.

[[Page 25443]]

 100% of the chronic RfDs in the absence of additional 
safety factors, as is the case for halosulfuron-methyl).
    Short- and intermediate-term exposure and risk. Margins of 
exposures (MOEs) can be calculated for food as well as residential 
exposures. The short-term NOAEL for females 13+ and infants and 
children is 50 mg/kg/day. Comparing the NOAEL of 50 mg/kg/day with the 
chronic food exposure from the DEEM analysis of 0.00025 mg/kg /day for 
females 13+ np/nn and 0.00075 mg/kg/day for infants/children results in 
food MOEs of 200,000 for females 13+ and 67,000 for infant/children.
    The intermediate-term NOAEL is based on the chronic dietary NOAEL 
of 10 mg/kg/day. Comparison of the NOAEL of 10 mg/kg/day with the 
chronic food exposures from DEEM of 0.00010 for adult males and females 
13+ np/nn and 0.00024 mg/kg/day for infants/children result in food 
MOEs of 100,000 for adult males and females 13+ and 42,000 for infants/
children.
    2. From drinking water. There are no established Maximum 
Contaminant Levels (MCL) for residues of halosulfuron-methyl in 
drinking water. It is not listed for MCL development or drinking water 
monitoring under the Safe Drinking Water Act nor is it a target of 
EPA's National Survey of Wells for Pesticides. No health advisory 
levels for halosulfuron-methyl in drinking water have been established. 
There are no information of any halosulfuron-methyl detections in any 
wells, ponds, lakes or streams resulting from its use in the United 
States. No monitoring data on residues of halosulfuron-methyl in 
surface and ground water are readily available. EPA used the SCI-GROW 
(Screening Concentration In Ground Water) to estimate residues of 
halosulfuron-methyl in ground water and the PRZM/EXAMS II to estimate 
the surface water concentrations. The SCI-GROW model is derived from a 
maximum 90-day average concentrations from monitoring studies conducted 
at sites believed to be vulnerable to, and under conditions likely to 
result in ground water contamination. Since variations in ground water 
concentrations are generally relatively minor over time periods of 
interest, the concentrations can be considered both acute and chronic 
values.
    The estimated drinking water environmental concentrations (DWEC) 
for halosulfuron-methyl in ground water (acute and chronic) is 0.008 
gram/Liter (g/L). The estimated acute and chronic 
DWECs for surface water are 4.3 g/L and 1.1 g/L, 
respectively. These estimates are based on a maximum application rate 
of 0.063 lbs. active ingredient/acre (ai/A) which may be applied twice 
per use season. Drinking water levels of comparisons (DWLOCs) for 
acute, short-term, intermediate-term, and chronic exposure were 
calculated and compared with DWECs. The Agency's default body weights 
and consumption values used to calculate DWLOCs are 70 kg/2L for adult 
males; 60 kg/2L for adult females; and 10 kg/1L for children.
    i. Acute exposure and risk. EPA has calculated a DWLOC for acute 
exposure to halosulfuron-methyl in drinking water for the relevant 
population subgroups, females 13+ years of age and infants and 
children. The acute DWLOC is 15,000 g/L for females (13+ years 
old) and 5,000 g/L for infants and children, which is 
substantially higher than the DWECs for surface water (4.3 g/
L) and ground water (0.008 g/L). Acute exposure to 
halosulfuron-methyl in drinking water is below the calculated drinking 
water level of concern.
    ii. Chronic exposure and risk. EPA has calculated the DWLOCs for 
chronic exposure to halosulfuron-methyl in drinking water. For chronic 
exposure to halosulfuron-methyl in surface and ground water, the DWLOCs 
are 3,500 g/L for the U.S. population (48 states), 3,000 
g/L for females 13+ years and 1,000 g/L for infants/
children, which are substantially higher than the chronic surface water 
DWEC of 1.1 g/L and the ground water DWEC of 0.008 g/
L. Chronic exposure to halosulfuron-methyl in drinking water is below 
the calculated drinking water level of concern.
    iii. Short-term and intermediate-term exposure and risk. The short-
term DWLOCs calculated for drinking water are 10,000 g/L for 
females 13+ and 3,700 g/L for infants and children. The 
intermediate term DWLOCs calculated for drinking water are 590 
g/L for adult males; 57 g/L for females (13+ np/nn) 
and 160 g/L for infants and children. Intermediate-term DWLOCs 
are substantially higher than the DWEC for chronic surface water (1.1 
g/L). Short-term DWLOCs substantially higher than the DWEC for 
acute surface water (4.3 g/L. Short- and intermediate- term 
exposures are below the calculated drinking water levels of concern.
    3. From non-dietary exposure. Halosulfuron-methyl is currently 
registered for use on the following residential non-food sites: 
commercial and residential turf and on other non-crop sites including 
airports, cemeteries, fallow areas, golf courses, landscaped areas, 
public recreation areas, residential property, road sides, school 
grounds, sod or turf seed farms, sports fields, landscaped areas, with 
established woody ornamentals and other similar use sites. For 
residential handlers and postapplication activities, short- to 
intermediate-term exposures may occur. Chronic exposures (6 or more 
months of continuous exposure) are not expected.
    i. Acute exposure and risk. There is a potential for exposure to 
halosulfuron-methyl by homeowner mixer/loaders. However, since 
endpoints for acute dermal or inhalation were not identified, the use 
on residential non-food sites is not expected to pose an unacceptable 
acute risk.
    ii. Chronic exposure and risk. Chronic exposures for residential 
use are not expected. A chronic non-dietary endpoint was not 
identified, therefore the use on residential non-food sites is not 
expected to pose an unacceptable chronic risk.
    iii. Short- and intermediate-term exposure and risk. There is a 
potential for short-term and intermediate-term dermal exposure to 
residential handlers. Chemical specific or site specific data are not 
available to assess residential exposure to residues of halosulfuron-
methyl on turf, therefore, the DRAFT Standard Operating Procedures 
(SOP) for Residential Exposure Assessments were employed to assess the 
following postapplication exposure scenarios: (a) dermal exposure from 
pesticide residues on turf; (b) children's incidental nondietary 
ingestion of pesticide residues on residential lawn from hand-to-mouth 
transfer; and (c) children's ingestion of pesticide-treated turfgrass.
    For residential handlers the default assumptions for area treated 
and exposure duration time were selected from the DRAFT SOP for 
Residential Exposure Assessments (December 18, 1997). The SOP does not 
list a mixer/loader/applicator scenario for dry flowable (water-
dispersible granule). Therefore, the unit exposure for ``garden hose 
end sprayer/liquid/open pour (MLAP)'' was selected as a default value. 
Based on Pesticide Handlers Exposure Data (PHED), a liquid formulation 
is believed to have a higher dermal exposure potential than a dry 
flowable. Default assumptions were used with the maximum application 
rate on the label to estimate residential handler exposure to 
halosulfuron-methyl. According to Table A-1 of the SOPs for Residential 
Exposure Assessments, the method used for estimating residential 
applicator exposure is believed to produce a central tendency to high-
end estimate of exposure.

[[Page 25444]]

    The short-term dermal MOE for residential handlers (60 kg adult) is 
4,200. This MOE is greater than 100 and therefore does not exceed EPAs 
level of concern.
    For adult and children postapplication scenarios the default 
assumptions, such as dermal transfer coefficient, exposure time, hand 
surface area, ingestion frequency, residue dissipation, and ingestion 
rates, were selected from the DRAFT SOPs for Residential Exposure 
Assessments (December 18, 1997). The dislodgeable foliar residue value 
used for intermediate exposure estimates was based on the average of 
the first 10-days (20% for fraction of ai retained on the foliage and 
10% for fraction of residue that dissipates daily). Default assumptions 
were used with the maximum application rate on the label to estimate 
postapplication exposure to children and adults from treated lawns. 
According to Table A-1 of the SOP's for Residential Exposure 
Assessments, the method used for estimating postapplication exposure is 
believed to produce a high-end estimate of exposure.
    The short-term dermal exposure and risk from treated lawn MOEs for 
adult females, adult males, and children are 330, 390, and 420, 
respectively. The intermediate-term dermal MOEs for adult females, 
adult males, and children are 100, 120, and 130, respectively. Both 
short and intermediate-term dermal MOEs are 100 or greater, and 
therefore do not exceed EPA's level of concern.
    The short- and intermediate-term oral exposure and risk for hand to 
mouth transfer MOEs for children are 4,900 and 1,500, respectively. 
Both short and intermediate-term oral MOEs are greater than 100, and 
therefore do not exceed EPA's level of concern.
    The short- and intermediate-term oral exposure and risk incidental 
ingestion MOEs for children are 210,000 and 66,000, respectively. Both 
short and intermediate MOEs are greater than 100, and therefore do not 
exceed EPAs level of concern.
    4. 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 halosulfuron-methyl 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, 
halosulfuron-methyl 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 halosulfuron-methyl has a 
common mechanism of toxicity with other substances. For information 
regarding EPA's efforts to determine which chemicals have a common 
mechanism of toxicity and to evaluate the cumulative effects of such 
chemicals, see the final rule for Bifenthrin Pesticide Tolerances (62 
FR 62961, November 26, 1997).

D. Aggregate Risks and Determination of Safety for U.S. Population

    1. Acute risk. Acute aggregate risk includes exposure form food + 
water. The risk from acute ``food only'' exposure is less than 1% of 
the RfD for all population subgroups which is less than the Agency's 
level of concern (100% of the RfD). The lowest DWLOC calculated was 
5,000 g/L for infants/children. The DWLOC calculated for 
females (13+ np/nn) was 15,000 g/L. Both of these levels are 
higher than the DWLOC for acute surface water (4.3 g/L) and 
ground water (0.008 g/L). Therefore, the risk from aggregate 
exposure to halosulfuron-methyl does not exceed EPAs level of concern.
    2. Chronic risk. Using the TMRC exposure assumptions described in 
this unit, EPA has concluded that aggregate exposure to halosulfuron-
methyl from food will utilize 0.1% of the RfD for the U.S. population. 
The major identifiable subgroup with the highest aggregate exposure is 
children (1-6) which utilizes 0.2% of the RfD as discussed below. EPA 
generally has no concern for exposures below 100% of the RfD because 
the RfD represents the level at or below which daily aggregate dietary 
exposure over a lifetime will not pose appreciable risks to human 
health. Despite the potential for exposure to halosulfuron-methyl in 
drinking water and from non-dietary, non-occupational exposure, EPA 
does not expect the aggregate exposure to exceed 100% of the RfD. EPA 
concludes that there is a reasonable certainty that no harm will result 
from aggregate exposure to halosulfuron-methyl residues.
    3. Short- and intermediate-term exposure and risk. Short- and 
intermediate-term aggregate exposure takes into account chronic dietary 
food and water (considered to be a background exposure level) plus 
short-term and intermediate-term residential exposure. For 
halosulfuron-methyl, EPA has determined that it is appropriate to 
aggregate exposure via the oral route (from food and water) with those 
via oral and dermal routes from residential uses. The MOEs can be 
calculated for dietary as well as residential exposures. However, there 
are no drinking water estimates (only estimates of surface water). 
Assuming a minimum Aggregate MOE of 100, short-term DWLOC was 
calculated. MOEs for ``food only'' and residential exposures are 
200,000 and 310 for females 13+. The short-term DWLOC for females 13+ 
years is 10,000 g/L. Short-term aggregate DWLOCs are 
substantially higher than the DWEC for acute surface water (4.3 
g/L). The food and residential (oral and dermal) MOEs are well 
above the acceptable short-term aggregate MOE of 100. Therefore, short-
term aggregate risk does not exceed EPA's level of concern. These 
estimates of food and residential exposure are considered to be 
somewhat conservative.
    Intermediate-term aggregate exposure takes into account chronic 
dietary food and water (considered to be a background exposure level) 
plus intermediate-term residential uses. The MOEs for ``food only'' and 
residential exposures are 100,000 and 120 for adult males, 100,000 and 
102 for females 13+. The intermediate-term DWLOCs are 590 g/L 
and 57 g/L, respectively for adult males and females 13+ 
years. Intermediate-term DWLOCs are substantially higher than the DWEC 
for chronic surface water (1.1 g/L). The MOEs for food only 
and residential exposure (dermal) are higher than 100. Therefore, 
intermediate-term aggregate risk does not exceed EPA's level of 
concern.
    4. Aggregate cancer risk for U.S. population. EPA has classified 
halosulfuron-methyl as a ``not likely'' carcinogen (no evidence of 
carcinogenicity to humans) based on the lack of evidence of 
carcinogenicity in mice and rats and therefore has a reasonable 
certainty that no harm will result from exposure to residues of 
halosulfuron-methyl.
    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 halosulfuron-methyl 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 halosulfuron-methyl, EPA considered

[[Page 25445]]

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 gestation. 
Reproduction studies provide information relating to effects from 
exposure to the pesticide on the reproductive capability of mating 
animals and data on systemic toxicity.
    FFDCA section 408 provides that EPA shall apply an additional 
tenfold margin of safety for infants and children in the case of 
threshold effects to account for pre-and post-natal toxicity and the 
completeness of the 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 uncertainty factor (usually 100 for combined inter- 
and intra-species variability) and not the additional tenfold MOE/
uncertainty factor when EPA has a complete data base under existing 
guidelines and when the severity of the effect in infants or children 
or the potency or unusual toxic properties of a compound do not raise 
concerns regarding the adequacy of the standard MOE/safety factor.
    ii. Pre- and postnatal sensitivity. Based on the developmental and 
reproductive toxicity studies, there is no indication of increased 
sensitivity of rats or rabbits to in utero and/or postnatal exposure to 
halosulfuron-methyl. In these studies, the effects in the fetuses/
offspring was observed only at or above treatment levels which resulted 
in evidence of parental toxicity.
    The EPA determined that a postnatal developmental neurotoxicity 
study in rats is required based on the following weight-of-evidence 
considerations: (a) In the developmental toxicity study in rats, there 
was evidence of alterations to the development of the fetal nervous 
system at 750 mg/kg/day (highest dose tested) including dilation of the 
lateral ventricles (16 fetuses/5 litters), dilation of the third 
ventricle (1/1), spinal cord agenesis (1/1) and adrenal agenesis (1/1) 
at the high dose; and malformed brain cortex (1/1) at 250 mg/kg/day; 
(b) There was no evaluation of perfused nervous system tissues, since 
acute and subchronic neurotoxicity studies in rats were not required. 
The primary concern is the lack of information in the data base that 
would allow the determination of whether functional deficits would be 
observed at dose levels below those which result in frank malformations 
of the central nervous system.
    iii. Conclusion. Except for the pending requirements for a 
developmental neurotoxicity study, the toxicity data base is complete 
for halosulfuron-methyl and exposure data is complete or is estimated 
based on data that reasonably accounts for potential exposures. EPA 
concludes, based on reliable data, that use of the standard margin of 
safety will be safe for infants and children without the addition of 
another tenfold factor. The requirement of a developmental 
neurotoxicity study in rats did not warrant application of additional 
safety factor because: (a) the alterations observed in the fetal 
nervous system occurred in only one species (in rats and not in 
rabbits); (b) the fetal effects which will be investigated in the 
required developmental neurotoxicity study were seen only at a dose of 
750 mg/kg/day which is close to the limit-dose (1,000 mg/kg/day); (c) 
there was no evidence of clinical signs of neurotoxicity, brain weight 
changes, or neuropathology in the subchronic or chronic studies in 
rats; (d) the developmental neurotoxicity study is required only as 
confirmatory data to understand what the effect is at a high exposure 
(dose) level; and (e) exposure assessments do not indicate a concern 
for potential risk to infants and children based on the results of the 
field trial studies and the very low application rat (0.06 lbs ai/A). 
Detectable residues are not expected in human foods.
    2. Acute risk. The acute dietary RfD was determined to be 0.5 mg/
kg/day based on the NOAEL from the developmental rabbit study (50 mg/
kg/day) and a safety factor of 100. Based on the high-end exposures, 
the percent of the RfD occupied for the U.S. population was 0.06%, 
0.15% for non-nursing infants (<1 year old) and 0.05% females 13+ years 
old. The subgroup with the highest exposure was the non-nursing infants 
(<1 year old). The drinking water level of comparison (DWLOC) for acute 
exposure to halosulfuron-methyl residues for infants/children is 5,000 
g/L. The maximum concentration of halosulfuron-methyl in 
drinking water (4.3 g/L) is less than EPA's level of 
comparison for halosulfuron-methyl in drinking water as a contribution 
to acute aggregate exposure. Therefore, EPA concludes with reasonable 
certainty that the potential risk from aggregate acute exposure (food 
and water) would not exceed the Agency's level of concern.
    3. Chronic risk. Using the exposure assumptions described in this 
unit, EPA has concluded that aggregate exposure to halosulfuron-methyl 
from food will utilize 0.2% of the RfD for infants and children. EPA 
generally has no concern for exposures below 100% of the RfD because 
the RfD represents the level at or below which daily aggregate dietary 
exposure over a lifetime will not pose appreciable risks to human 
health. Despite the potential for exposure to halosulfuron-methyl in 
drinking water and from non-dietary, non-occupational exposure, EPA 
does not expect the aggregate exposure to exceed 100% of the RfD.
    4. Short- or intermediate-term risk. An aggregate exposure estimate 
and risk assessment was calculated for postapplication exposure to 
halosulfuron from treated lawns. Short-term MOEs for food, residential 
oral, and residential dermal are 67,000, 5,000, and 420 respectively, 
for infants and children. The intermediate-term MOEs for food, 
residential oral, and residential dermal are 42,000, 1,500, and 130, 
respectively for infants and children. The short and intermediate-term 
DWLOCs for infants and children were 3,700 and 160 mg/L, respectively. 
The short and intermediate DWLOCs are substantially higher than the 
DWECs for acute surface water (4.3 g/L) and chronic surface 
water (1.1 g/L). The food and residential MOEs are above the 
acceptable aggregate MOE of 100. Therefore, short-and intermediate-term 
aggregate risk does not exceed EPAs level of concerns for infants and 
children.
    5. 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 halosulfuron-methyl 
residues.

III. Other Considerations

A. Metabolism In Plants and Animals

    Plant metabolism studies have been submitted and reviewed for corn, 
sugarcane, and soybean. These studies show that the primary residue 
resulting from preemergence applications is 3-chlorosulfonamide acid. 
With postemergence application, the major residue is parent 
halosulfuron-methyl, except in corn, in which 3-chlorosulfonamide acid 
predominates. Inadvertent residues in rotational crops are also 
primarily 3-chlorosulfonamide acid. However, 3-chlorosulfonamide acid 
is not of toxicological concern and the residue to be regulated in 
plants is halosulfuron-methyl per se, as

[[Page 25446]]

determined by the HED Metabolism Committee.
    Goat and hen metabolism studies on halosulfuron-methyl have been 
accepted by EPA. As with plants, the residue of concern in animals is 
halosulfuron-methyl per se. The current Agency-approved method for 
enforcement of tolerances for halosulfuron-methyl in animal commodities 
is based on analysis of the chlorosulfonamide half of the halosulfuron-
methyl molecule; thus, it quantitates residues of parent halosulfuron-
methyl as well as those metabolites containing the chlorosulfonamide 
acid moiety (i.e., it is not specific to halosulfuron-methyl per se.) 
The requested uses are not expected to increase the residues in animal 
commodities above those already regulated by 40 CFR 180.479. Animal 
tolerances will still be expressed as halosulfuron-methyl and its 
metabolites determined as 3-chlorsulfonic acid, expressed as parent 
equivalent.

B. Analytical Enforcement Methodology

    Adequate analytical methodology (gas chromatography with electron 
capture detection) is available for enforcement of tolerances for 
halosulfuron-methyl in animal commodities. Adequate analytical 
methology (gas chromatography/thermionic specific is available for 
enforcement of tolerances for halosulfuron in plant commodities.
    Adequate enforcement methodology (gas chromatography) is available 
to enforce the tolerance expression. The method may be requested from: 
Calvin Furlow, PIRIB, 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. Magnitude of Residues

    The available crop field trial data support the establishment of 
tolerances for residues of the herbicide halosulfuron-methyl, [methyl 
5-[( 4,6-dimethoxy-2-pyrimidinyl) amino] carbonylaminosulfonyl-3-
chloro-1-methyl-1H-pyrazole-4-carboxylate] in or on the raw 
agricultural commodities almond, hull at 0.2 part per million (ppm); 
corn, field, fodder at 0.8 ppm; corn, field, forage at 0.2 ppm; corn, 
field, grain at 0.05 ppm; corn, pop, fodder at 0.8 ppm; corn, pop, 
grain at 0.05 ppm; corn, sweet, fodder, at 0.8 ppm; corn, sweet forage 
at 0.2 ppm; corn, sweet, kernel + cob with husks removed at 0.05 ppm; 
cotton, gin by products at 0.05 ppm; cotton, undelinted seed at 0.05 
ppm; pistachio, nutmeat at 0.05 ppm rice, grain at 0.05 ppm, rice, 
straw at 0.2 ppm; sorghum, grain, fodder/stover at 0.1 ppm sorghum, 
grain, forage at 0.05 ppm, sorghum, grain, grain at 0.05 ppm; 
sugarcane, cane at 0.05 ppm; and tree nuts (crop group 14), nutmeat at 
0.05 ppm.
    The available crop residue data also support the deletion of the 
current established tolerances for soybean, forage at 0.5 ppm; soybean, 
hay at 0.5 ppm; soybean, seed at 0.5 ppm wheat, forage at 0.1 ppm; 
wheat, grain at 0.1 ppm; and wheat, straw at 0.2 ppm.

D. International Residue Limits

    There are no CODEX, Canadian, or Mexican maximum residue limits 
(MRLs ) established for halosulfuron-methyl, therefore harmonization is 
not an issue.

E. Rotational Crop Restrictions

    Tolerances were previously established for inadvertent residues in 
rotational crops. These tolerances were based on residues of 3-
chlorosulfonamide acid which is not of toxicological concern and is no 
longer being regulated by EPA in plant commodities. Therefore, 
rotational crop tolerances are not necessary and are being deleted by 
this rule.

IV. Conclusion

    Therefore, tolerances are established for residues of methyl 5-
[(4,6-dimethoxy-2-pyrimidinyl)amino] carbonylaminosulfonyl-3-chloro-1-
methyl-1H-pyrazole-4-carboxylate in almond, hulls at 0.2 ppm; corn, 
field, fodder at 0.8 ppm; corn, field, forage at 0.2 ppm; corn, field, 
grain at 0.05 ppm; corn, pop, fodder at 0.8 ppm, corn, pop, grain at 
0.05 ppm; corn, sweet, fodder/stover at 0.8 ppm; corn, sweet, forage at 
0.2 ppm; corn, sweet, kernel + cob with husks removed at 0.05 ppm; 
cotton, gin by-products at 0.05 ppm; cotton, undelinted seed at 0.05 
ppm; pistachio, nutmeat at 0.05 ppm; rice, grain at 0.05 ppm; rice, 
straw at 0.2 ppm; sorghum, grain, fodder/stover at 0.1 ppm; sorghum; 
grain, forage at 0.05 ppm sorghum, grain, grain at 0.05 ppm; sugarcane, 
cane at 0.05 and tree nuts (crop group 14), nutmeat at 0.05 ppm.
    These entries for corn, field, fodder, corn, field, forage; corn, 
field, grain; sorghum, grain, fodder/stover; sorghum, grain, forage; 
and sorghum, grain, grain will replace current entries for these 
commodities.
    Established tolerances for indirect or inadvertent residues of the 
herbicide halosulfuron-methyl 5-[(4,6-dimethoxy-2-pyrimidinyl)amino] 
carbonylaminosulfonyl-3-chloro-1-methyl-1H-pyrazole- 4-carboxylate, and 
its metabolites determined as the 3-chloro-1-methyl-5-
sulfamoylpyrazole-4-carboxylic acid and expressed as parent equivalents 
in on the following raw agricultural commodities when present to 
growing crops: soybean, forage at 0.05 ppm; soybean, hay at 0.5 ppm; 
soybean, seed at 0.5 ppm; wheat, forage at 0.1 ppm wheat, grain at 0.1 
ppm, and wheat, straw at 0.1 ppm are being deleted.

V. Objections and Hearing Requests

    The new FFDCA section 408(g) provides essentially the same process 
for persons to ``object'' to a tolerance regulation 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 July 12, 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 
regulation. 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, [email protected]. Requests for waiver of tolerance 
objection fees should be sent to James Hollies, Information Resources 
and Services Division (7502C), Office of Pesticide Programs, 
Environmental Protection Agency, 401 M St., SW., Washington, DC 20460.

[[Page 25447]]

    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.

VI. Public Record and Electronic Submissions

    EPA has established a record for this regulation under docket 
control number [OPP-300854] (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:
    [email protected].


    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.

VII. Regulatory Assessment Requirements

A. Certain Acts and Executive Orders

    This final rule establishes, modifies, and revokes tolerances under 
section 408(d) of the FFDCA in response to a petition submitted to the 
Agency. The Office of Management and Budget (OMB) has determined that 
tolerance actions, in general, are ``not significant'' unless the 
action involves the revocation of a tolerance that may result in a 
substatial adverse and material affect on the economy. This final rule 
does not contain any information collections subject to OMB approval 
under the Paperwork Reduction Act (P.A.), 44 U.S.C. 3501 et seq., or 
impose any enforceable duty or contain any unfunded mandate as 
described under Title II of the Unfunded Mandates Reform Act of 1995 
(UMRA) (Pub. L. 104-4). Nor does it require 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).
    In addition, since tolerances and exemptions that are established, 
modified or revoked on the basis of a petition under FFDCA section 
408(d), such as the tolerance in this final rule, do not require the 
issuance of a proposed rule, the requirements of the Regulatory 
Flexibility Act (RFA) (5 U.S.C. 601 et seq.) do not apply. 
Nevertheless, the Agency 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 
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

[[Page 25448]]

Indian tribal governments. This action does not involve or impose any 
requirements that affect Indian tribes. Accordingly, the requirements 
of section 3(b) of Executive Order 13084 do not apply to this rule.

VIII. Submission to Congress and the Comptroller General

    The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the 
Small Business Regulatory Enforcement Fairness Act of 1996, generally 
provides that before a rule may take effect, the Agency promulgating 
the rule must submit a rule report, which includes a copy of the rule, 
to each House of the Congress and 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: April 29, 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. Section 180.479, is revised to read as follows:


Sec. 180.479  Halosulfuron; tolerances for residues.

    (a) General. (1) Tolerances are established for residues of the 
herbicide halosulfuron, methyl 5-[(4,6-dimethoxy-2-pyrimidinyl) amino] 
carbonylaminosulfonyl-3-chloro-1-methyl-1H-pyrazole-4-carboxylate, and 
its metabolites determined as 3-chloro-1-methyl-5-sulfamoylpyrazole-4-
carboxylic acid and expressed as parent equivalents, in or on the raw 
agricultural commodities listed below.

 
------------------------------------------------------------------------
                   Commodity                        Parts per million
------------------------------------------------------------------------
Cattle, mybp...................................                      0.1
Goats, mbyp....................................                      0.1
Hogs, mbyp.....................................                      0.1
Horses, mbyp...................................                      0.1
Sheep, mbyp....................................                      0.1
------------------------------------------------------------------------

    (2) Tolerances are established for residues of the herbicide 
halosulfuron-methyl, methyl 5-[(4,6-dimethoxy-2-pyrimidinyl) 
amino]carbonylaminosulfonyl-3-chloro-1-methyl-1H-pyrazole- 4-
carboxylate, in or on the raw agricultural commodities listed below.

 
------------------------------------------------------------------------
                   Commodity                        Parts per million
------------------------------------------------------------------------
Almond, hulls..................................                      0.2
Corn, field, fodder............................                      0.8
Corn, field, forage............................                      0.2
Corn, field, grain.............................                     0.05
Corn, pop, fodder..............................                      0.8
Corn, pop, grain...............................                     0.05
Corn, sweet, fodder/stover.....................                      0.8
Corn, sweet, forage............................                      0.2
Corn, sweet, kernel + cob with husks removed...                     0.05
Cotton, gin by-products........................                     0.05
Cotton, undelinted seed........................                     0.05
Pistachio, nutmeat.............................                     0.05
Rice, grain....................................                     0.05
Rice, straw....................................                      0.2
Sorghum, grain, fodder/stover..................                      0.1
Sorghum, grain, forage.........................                     0.05
Sorghum, grain, grain..........................                     0.05
Sugarcane, cane................................                     0.05
Tree nuts (crop group 14), nutmeat.............                     0.05
------------------------------------------------------------------------


    (b) Section 18 emergency exemptions. [Reserved]
    (c) Tolerances with regional registrations. [Reserved]
    (d) Indirect or inadvertent residues. [Reserved]

[FR Doc. 99-11835 Filed 5-11-99; 8:45 am]
BILLING CODE 6560-50-F