Halosulfuron-methyl; Pesticide Tolerances for Emergency Exemptions, 51615-51623 [05-17204]

Agencies

• ENVIRONMENTAL PROTECTION AGENCY

[Federal Register Volume 70, Number 168 (Wednesday, August 31, 2005)]
[Rules and Regulations]
[Pages 51615-51623]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 05-17204]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[OPP-2005-0165; FRL-7719-8]


Halosulfuron-methyl; Pesticide Tolerances for Emergency 
Exemptions

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This regulation establishes a time-limited tolerance for 
residues of halosulfuron-methyl in or on sweet potatoes. This action is 
in response to EPA's granting of an emergency exemption under section 
18 of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) 
authorizing use of the pesticide on sweet potatoes. This regulation 
establishes a maximum permissible level for residues of halosulfuron-
methyl in this food commodity. The tolerance will expire and is revoked 
on December 31, 2008.

DATES: This regulation is effective August 31, 2005. Objections and 
requests for hearings must be received on or before October 31, 2005.

ADDRESSES: To submit a written objection or hearing request follow the 
detailed instructions as provided in Unit VII. of the SUPPLEMENTARY 
INFORMATION. EPA has established a docket for this action under docket 
identification (ID) number OPP-2005-0165. All documents in the docket 
are listed in the EDOCKET index at https://www.epa.gov/edocket/. 
Although listed in the index, some information is not publicly 
available, i.e., Confidential Business Information (CBI) or other 
information whose disclosure is restricted by statute. Certain other 
material, such as copyrighted material, is not placed on the Internet 
and will be publicly available only in hard copy form. Publicly 
available docket materials are available either electronically in 
EDOCKET or in hard copy at the Public Information and Records Integrity 
Branch (PIRIB), Rm. 119, Crystal Mall 2, 1801 S. Bell St., 
Arlington, VA. This docket facility is open from 8:30 a.m. to 4 p.m., 
Monday through Friday, excluding legal holidays. The docket telephone 
number is (703) 305-5805.

FOR FURTHER INFORMATION CONTACT: Andrew Ertman, Registration Division 
(7505C), Office of Pesticide Programs, Environmental Protection Agency, 
1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone 
number: (703) 308-9367; e-mail address: ertman.andrew@epa.gov.

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this Action Apply to Me?

    You may be potentially affected by this action if you are an 
agricultural producer, food manufacturer, or pesticide manufacturer. 
Potentially affected entities may include, but are not limited to:
     Crop production (NAICS code 111).
     Animal production (NAICS code 112).
     Food manufacturing (NAICS code 311).
     Pesticide manufacturing (NAICS code 32532).
    This listing is not intended to be exhaustive, but rather provides 
a guide for readers regarding entities likely to be affected by this 
action. Other types of entities not listed in this unit could also be 
affected. The North American Industrial Classification System (NAICS) 
codes have been provided to assist you and others in determining 
whether this action might apply to certain entities. If you have any 
questions regarding the applicability of this action to a particular 
entity, consult the person listed under FOR FURTHER INFORMATION 
CONTACT.

B. How Can I Access Electronic Copies of this Document and Other 
Related Information?

    In addition to using EDOCKET (https://www.epa.gov/edocket/), you may 
access this Federal Register document electronically through the EPA 
Internet under the ``Federal Register'' listings at https://www.epa.gov/
fedrgstr/. A frequently updated electronic version of 40 CFR part 180 
is available on E-CFR Beta Site Two at https://www.gpoaccess.gov/ecfr/.

II. Background and Statutory Findings

    EPA, on its own initiative, in accordance with sections 408(e) and 
408(l)(6) of the Federal Food, Drug, and Cosmetic Act (FFDCA), 21 
U.S.C. 346a, is establishing a tolerance for residues of the herbicide 
halosulfuron-methyl, in or on sweet potatoes at 1.0 parts per million 
(ppm). This tolerance will expire and is revoked on December 31, 2008. 
EPA will publish a document in the Federal Register to remove the 
revoked tolerance from the Code of Federal Regulations (CFR).
    Section 408(l)(6) of FFDCA requires EPA to establish a time-limited 
tolerance or exemption from the requirement for a tolerance for 
pesticide chemical residues in food that will result from the use of a 
pesticide under an emergency exemption granted by EPA under section 18 
of FIFRA. Such tolerances can be established without providing notice 
or period for public comment. EPA does not intend for its actions on 
FIFRA section 18 related tolerances to set binding precedents for the 
application of section 408 of FFDCA and the new safety standard to 
other tolerances and exemptions. Section 408(e) of FFDCA allows EPA to 
establish a tolerance or an exemption from the requirement of a 
tolerance on its own initiative, i.e., without having received any 
petition from an outside party.
    Section 408(b)(2)(A)(i) of FFDCA allows EPA to establish a 
tolerance (the legal limit for a pesticide chemical residue in or on a 
food) only if EPA determines that the tolerance is ``safe.''

[[Page 51616]]

Section 408(b)(2)(A)(ii) of FFDCA defines ``safe'' to mean that ``there 
is a reasonable certainty that no harm will result from aggregate 
exposure to the pesticide chemical residue, including all anticipated 
dietary exposures and all other exposures for which there is reliable 
information.'' This includes exposure through drinking water and in 
residential settings, but does not include occupational exposure. 
Section 408(b)(2)(C) of FFDCA requires EPA to give special 
consideration to exposure of infants and children to the pesticide 
chemical residue in establishing a tolerance and to ``ensure that there 
is a reasonable certainty that no harm will result to infants and 
children from aggregate exposure to the pesticide chemical residue. . . 
.''
    Section 18 of FIFRA authorizes EPA to exempt any Federal or State 
agency from any provision of FIFRA, if EPA determines that ``emergency 
conditions exist which require such exemption.'' This provision was not 
amended by the Food Quality Protection Act of 1996 (FQPA). EPA has 
established regulations governing such emergency exemptions in 40 CFR 
part 166.

III. Emergency Exemption for Halosulfuron-methyl on Sweet Potatoes and 
FFDCA Tolerances

    Several sweet potato growing States requested the use of 
halosulfuron-methyl due to resistance to pesticides registered for the 
control of the weed purple nutsedge in sweet potato fields. EPA has 
authorized under section 18 of FIFRA the use of halosulfuron-methyl on 
sweet potatoes for control of purple nutsedge in Louisiana, 
Mississippi, and North Carolina. After having reviewed the submissions, 
EPA concurs that emergency conditions exist for these States.
    As part of its assessment of this emergency exemption, EPA assessed 
the potential risks presented by residues of halosulfuron-methyl in or 
on sweet potatoes. In doing so, EPA considered the safety standard in 
section 408(b)(2) of FFDCA, and EPA decided that the necessary 
tolerance under section 408(l)(6) of FFDCA would be consistent with the 
safety standard and with section 18 of FIFRA. Consistent with the need 
to move quickly on the emergency exemption in order to address an 
urgent non-routine situation and to ensure that the resulting food is 
safe and lawful, EPA is issuing this tolerance without notice and 
opportunity for public comment as provided in section 408(l)(6) of 
FFDCA. Although this tolerance will expire and is revoked on December 
31, 2008, under section 408(l)(5) of FFDCA, residues of the pesticide 
not in excess of the amounts specified in the tolerance remaining in or 
on sweet potatoes after that date will not be unlawful, provided the 
pesticide is applied in a manner that was lawful under FIFRA, and the 
residues do not exceed a level that was authorized by this tolerance at 
the time of that application. EPA will take action to revoke this 
tolerance earlier if any experience with, scientific data on, or other 
relevant information on this pesticide indicate that the residues are 
not safe.
    Because this tolerance is being approved under emergency 
conditions, EPA has not made any decisions about whether halosulfuron-
methyl meets EPA's registration requirements for use on sweet potatoes 
or whether a permanent tolerance for this use would be appropriate. 
Under these circumstances, EPA does not believe that this tolerance 
serves as a basis for registration of halosulfuron-methyl by a State 
for special local needs under section 24(c) of FIFRA. Nor does this 
tolerance serve as the basis for any State other than Louisiana, 
Mississippi, and North Carolina to use this pesticide on this crop 
under section 18 of FIFRA without following all provisions of EPA's 
regulations implementing section 18 of FIFRA as identified in 40 CFR 
part 166. For additional information regarding the emergency exemption 
for halosulfuron-methyl, contact the Agency's Registration Division at 
the address provided under FOR FURTHER INFORMATION CONTACT.

IV. Aggregate Risk Assessment and Determination of Safety

    EPA performs a number of analyses to determine the risks from 
aggregate exposure to pesticide residues. For further discussion of the 
regulatory requirements of section 408 of FFDCA and a complete 
description of the risk assessment process, see the final rule on 
Bifenthrin Pesticide Tolerances (62 FR 62961, November 26, 1997) (FRL-
5754-7).
    Consistent with section 408(b)(2)(D) of FFDCA , EPA has reviewed 
the available scientific data and other relevant information in support 
of this action. EPA has sufficient data to assess the hazards of 
halosulfuron-methyl and to make a determination on aggregate exposure, 
consistent with section 408(b)(2) of FFDCA, for a time-limited 
tolerance for residues of halosulfuron-methyl in or on sweet potatoes 
at 1.0 ppm. EPA's assessment of the dietary exposures and risks 
associated with establishing the tolerance follows.

A. Toxicological Endpoints

    The dose at which no adverse effects are observed (the NOAEL) from 
the toxicology study identified as appropriate for use in risk 
assessment is used to estimate the toxicological endpoint. However, the 
lowest dose at which adverse effects of concern are identified (the 
LOAEL) is sometimes used for risk assessment if no NOAEL was achieved 
in the toxicology study selected. An uncertainty factor (UF) is applied 
to reflect uncertainties inherent in the extrapolation from laboratory 
animal data to humans and in the variations in sensitivity among 
members of the human population as well as other unknowns. An UF of 100 
is routinely used, 10X to account for interspecies differences and 10X 
for intra species differences. For halosulfuron-methyl, the Agency 
identified the need for a developmental neurotoxicity (DNT) study. In 
the absence of a DNT study, EPA concluded that an additional database 
UF of 3X is needed for all dietary and residential (non-dietary) 
exposure scenarios until the data are received and evaluated. An UF of 
3X (as opposed to a higher value) was viewed to be adequate because the 
NOAEL of 50 mg/kg/day (used for acute dietary, short-term incidental 
oral and inhalation risk assessments) and the NOAEL of 10 mg/kg/day 
(used for chronic dietary and intermediate-term incidental oral, 
dermal, and inhalation risk assessments) are 5X and 25X lower, 
respectively, than the NOAEL of 250 mg/kg/day in the rat developmental 
study where alterations of the fetal nervous system were seen at 750 
mg/kg/day (LOAEL). Consequently, based on the available data it is 
unlikely the results of the DNT would impact the overall risk 
assessment.
    For dietary risk assessment (other than cancer) the Agency uses the 
UF to calculate an acute or chronic reference dose (acute RfD or 
chronic RfD) where the RfD is equal to the NOAEL divided by the 
appropriate UF (RfD = NOAEL/UF). Where an additional safety factor is 
retained due to concerns unique to the FQPA, this additional factor is 
applied to the RfD by dividing the RfD by such additional factor. The 
acute or chronic population adjusted dose (aPAD or cPAD) is a 
modification of the RfD to accommodate this type of FQPA Safety Factor 
(SF).
    For non-dietary risk assessments (other than cancer) the UF is used 
to determine the level of concern (LOC). For example, when 100 is the 
appropriate UF (10X to account for interspecies differences and 10X for 
intraspecies differences) the LOC is 100.

[[Page 51617]]

 To estimate risk, a ratio of the NOAEL to exposures (margin of 
exposure (MOE) = NOAEL/exposure) is calculated and compared to the LOC.
    The linear default risk methodology (Q*) is the primary method 
currently used by the Agency to quantify carcinogenic risk. The Q* 
approach assumes that any amount of exposure will lead to some degree 
of cancer risk. A Q* is calculated and used to estimate risk which 
represents a probability of occurrence of additional cancer cases 
(e.g., risk is expressed as 1 x10-\6\ or one in a million). 
Under certain specific circumstances, MOE calculations will be used for 
the carcinogenic risk assessment. In this non-linear approach, a 
``point of departure'' is identified below which carcinogenic effects 
are not expected. The point of departure is typically a NOAEL based on 
an endpoint related to cancer effects though it may be a different 
value derived from the dose response curve. To estimate risk, a ratio 
of the point of departure to exposure (MOEcancer = point of 
departure/exposures) is calculated. A summary of the toxicological 
endpoints for halosulfuron-methyl used for human risk assessment is 
shown in Table 1 of this unit:

 Table 1.--Summary of Toxicological Dose and Endpoints for Halosulfuron-methyl for Use in Human Risk Assessment
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                                           Dose  milligram/
          Exposure scenario              kilogram/day (mg/kg/     Hazard based special      Endpoint for risk
                                             day)  UF/MOE               FQPA SF                 assessment
----------------------------------------------------------------------------------------------------------------
                                            Dietary risk assessments
----------------------------------------------------------------------------------------------------------------
Acute dietary                          NOAEL = 50 UF = 300\a\   1x                       Developmental toxicity--
Females 13-50 years of age...........  Acute RfD = 0.17 mg/kg/                            rabbit
                                        day.                                             LOAEL = 150 mg/kg/day
                                                                                          based on decreased
                                                                                          mean litter size,
                                                                                          increased number of
                                                                                          resorptions (total and
                                                                                          per dam) and increased
                                                                                          post-implantation
                                                                                          loss. (developmental
                                                                                          toxicity).
--------------------------------------
Chronic dietary                        NOAEL = 10 UF = 300\a\   1x                       Chronic toxicity--dog
All populations......................  Chronic RfD = 0.03 mg/                            LOAEL = 40 mg/kg/day
                                        kg/day.                                           based on decreased
                                                                                          body weight gains in
                                                                                          females.
--------------------------------------
Incidental oral                        NOAEL = 50               1x                       Developmental toxicity--
Short-term (1-30 days)...............  MOE = 300..............                            rabbit
Residential only.....................                                                    LOAEL = 150 mg/kg/day
                                                                                          based on decreased
                                                                                          body weight gain, food
                                                                                          consumption, and food
                                                                                          efficiency. (maternal
                                                                                          toxicity).
--------------------------------------
Incidental oral                        NOAEL = 10               1x                       13 Week Subchronic
Intermediate-term (1-6 months).......  MOE = 300..............                            toxicity--dog
Residential only.....................                                                    LOAEL = 40 mg/kg/day
                                                                                          based on decreased
                                                                                          body weight gain and
                                                                                          food efficiency in
                                                                                          females.
--------------------------------------
                                          Non-dietary risk assessments
----------------------------------------------------------------------------------------------------------------
Dermal                                 Dermal NOAEL = 100                                21-Day dermal toxicity
Short-term (1-30 days)...............                                                     study--rat
                                                                                         LOAEL = 1,000 mg/kg/day
                                                                                          based on decreased
                                                                                          body weight gain in
                                                                                          males.
----------------------------------------------------------------------------------------
Residential                            MOE = 300
--------------------------------------
Dermal\b\                              Oral NOAEL = 10                                   13 Week subchronic
Intermediate-term (1-6 months).......                                                     toxicity--dog
                                                                                         LOAEL = 40 mg/kg/day
                                                                                          based on decreased
                                                                                          body weight gain and
                                                                                          food efficiency in
                                                                                          females.
----------------------------------------------------------------------------------------
Residential                             MOE = 300               1x
--------------------------------------
Dermal\b\                              Oral NOAEL = 10          1x                       Chronic toxicity--dog
Long-term (> 6 months)...............  MOE = 300..............                           LOAEL = 40 mg/kg/day
Residential..........................                                                     based on decreased
                                                                                          body weight gains in
                                                                                          females.
--------------------------------------
Inhalation\c\                          Oral NOAEL = 10          1x                       13 Week subchronic
Intermediate-term (1-6 months).......  MOE = 300..............                            toxicity--dog
Residential..........................                                                    LOAEL = 40 mg/kg/day
                                                                                          based on decreased
                                                                                          body weight gain and
                                                                                          food efficiency in
                                                                                          females.
--------------------------------------
Inhalation\c\                          Oral NOAEL = 10          1x                       Chronic toxicity--dog
Long-term (> 6 months)...............  MOE = 300..............                           LOAEL = 40 mg/kg/day
Residential..........................                                                     based on decreased
                                                                                          body weight gains in
                                                                                          females.
--------------------------------------

[[Page 51618]]

 
Cancer                                  Classification: ``not likely to be carcinogenic to humans'' by the oral
                                               route, based on no evidence from studies in rats and mice.
----------------------------------------------------------------------------------------------------------------
\a\ UFDB = 300 (10x for inter-species extrapolation and 10 x for intra-species variability, 3x for lack of DNT).
\b\ A 75% dermal absorption factor should be used in route-to-route extrapolation.
\c\ Absorption via the inhalation route is presumed to be equivalent to oral absorption.

B. Exposure Assessment

    1. Dietary exposure from food, feed uses, and drinking water. 
Tolerances have been previously established (40 CFR 180.479) for the 
residues of halosulfuron-methyl, in or on a variety of raw agricultural 
commodities. The established tolerances include almond hulls; corn 
(sweet, kernel+cob with husks removed, field grain, fodder, forage, 
pop); cotton (gin by-products and undelinted seed); pistachio nutmeat; 
sugarcane; rice (grain, straw); and tree nuts (crop group 14). 
Additionally, tolerances are established (40 CFR 180.479 (a)(1)) for 
residues of halosulfuron-methyl and its metabolites determined as 3-
chloro-1-methyl-5-sulfamoylpyrazole-4-carboxylic acid (also referred to 
as CSA, expressed as parent equivalents) at 0.1 ppm in or on meat by-
products of cattle, goats, hogs, horses, and sheep.
    In conducting the acute and chronic dietary risk assessments, EPA 
used the Dietary Exposure Evaluation Model (DEEM\TM\) software. Modeled 
estimates of drinking water concentrations were directly entered into 
the exposure model to assess the contribution from drinking water. Risk 
assessments were conducted by EPA to assess dietary exposures from 
halosulfuron-methyl in food as follows:
    i. Acute exposure. Acute dietary risk assessments are performed for 
a food-use pesticide if a toxicological study has indicated the 
possibility of an effect of concern occurring as a result of a one day 
or single exposure. The DEEM\TM\ analysis evaluated the individual food 
consumption as reported by respondents in the U.S. Department of 
Agriculture (USDA) 1994-1996 and 1998 nationwide Continuing Surveys of 
Food Intake by Individuals (CSFII) and accumulated exposure to the 
chemical for each commodity. The following assumptions were made for 
the acute exposure assessments: Tolerance level residues and 100 
percent crop treated (PCT) for all commodities for which halosulfuron-
methyl tolerances are established and for the crop. Aggregate acute 
food and water exposure was determined by including modeled estimates 
of drinking water concentrations in the dietary model. The Agency used 
the acute water concentration (105 parts per billion (ppb)) derived 
from surface water modeling results, which was significantly higher 
than the modeled ground water concentration, and therefore protective 
of potential exposures via ground water sources of drinking water.
    ii. Chronic exposure. In conducting this chronic dietary risk 
assessment the DEEM\TM\ analysis evaluated the individual food 
consumption as reported by respondents in the USDA 1994-1996 and 1998 
nationwide CSFII and accumulated exposure to the chemical for each 
commodity. The following assumptions were made for the acute exposure 
assessments: tolerance level residues and 100 PCT for all commodities 
for which halosulfuron-methyl tolerances are established and for sweet 
potatoes. Aggregate chronic food and water exposure was determined by 
including modeled estimates of drinking water concentrations in the 
dietary model. The Agency used the chronic water concentration (105 
ppb) derived from surface water modeling results, which was 
significantly higher than the modeled ground water concentration, and 
therefore protective of potential exposures via ground water sources of 
drinking water.
    iii. Cancer. Halosulfuron-methyl is classified as a ``Not Likely'' 
human carcinogen. Therefore, risk assessments to assess cancer risk 
were not conducted.
    2. Dietary exposure from drinking water. The Agency lacks 
sufficient monitoring exposure data to complete a comprehensive dietary 
exposure analysis and risk assessment for halosulfuron-methyl in 
drinking water. Because the Agency does not have comprehensive 
monitoring data, drinking water concentration estimates are made by 
reliance on simulation or modeling taking into account data on the 
physical characteristics of halosulfuron-methyl.
    The Agency uses the First Index Reservoir Screening Tool (FIRST) or 
the Pesticide Root Zone/Exposure Analysis Modeling System (PRZM/EXAMS) 
to produce estimates of pesticide concentrations in an index reservoir. 
The Screening Concentration in Ground Water Modeling System (SCI-GROW) 
model is used to predict pesticide concentrations in shallow ground 
water. For a screening-level assessment for surface water EPA will 
generally use FIRST (a tier 1 model) before using PRZM/EXAMS (a tier 2 
model). The FIRST model is a subset of the PRZM/EXAMS model that uses a 
specific high-end runoff scenario for pesticides. While both FIRST and 
PRZM/EXAMS incorporate an index reservoir environment, the PRZM/EXAMS 
model includes a percent crop area factor as an adjustment to account 
for the maximum percent crop coverage within a watershed or drainage 
basin.
    None of these models include consideration of the impact processing 
(mixing, dilution, or treatment) of raw water for distribution as 
drinking water would likely have on the removal of pesticides from the 
source water.
    Based on the FIRST and SCI-GROW models the estimated environmental 
concentrations (EECs) of halosulfuron-methyl for acute exposures are 
estimated to be 105 ppb for surface water and 0.065 ppb for ground 
water. The EECs for chronic exposures are estimated to be 105 ppb for 
surface water and 0.065 ppb for ground water.
    3. From non-dietary exposure. The term ``residential exposure'' is 
used in this document to refer to non-occupational, non-dietary 
exposure (e.g., for lawn and garden pest control, indoor pest control, 
termiticides, and flea and tick control on pets). Halosulfuron-methyl 
is currently registered for use on the following residential non-
dietary sites: Residential turfgrass and landscaped areas.
    The short-term aggregate risk assessment estimates risks likely to

[[Page 51619]]

result from 1- to 30-day exposure to halosulfuron-methyl residues. A 
short-term risk assessment is required for adults because there are 
both residential handler and post-application exposure scenarios. In 
addition, a short-term risk assessment is required for infants and 
children because there is a residential post-application exposure 
scenario. Since the same effect was identified as the endpoint across 
all routes of exposure (decreased body-weight gain), MOEs are combined 
to result in an aggregate MOE (using the ``1/MOE Approach''). The 
Agency's level of concern for short-term exposure is an MOE of 300 or 
lower. Results from the short-term risk assessment indicate that all 
short-term aggregate MOEs are 3,100 or higher. Therefore, estimated 
aggregate (food + water + residential) exposure to halosulfuron-methyl 
are not of concern for short-term aggregate exposure.
    The intermediate-term aggregate risk assessment estimates risks 
likely to result from 1 to 6 months of exposure to halosulfuron-methyl 
residues from food, drinking water, and residential pesticide uses. An 
intermediate-term risk assessment is not required for adults because 
residential handler scenarios are not expected to occur for longer than 
a short-term time frame. However, an intermediate-term risk assessment 
is required for infants and children because there is a residential 
post-application oral exposure scenario. Since the same effect was 
identified as the endpoint across all routes of exposure (decreased 
body weight gain), MOEs are combined to result in an aggregate MOE 
(using the ``1/MOE Approach''). High-end estimates of residential 
exposure are used in the intermediate-term assessment, while average 
values are used for food and drinking water exposure. The Agency's 
level of concern for intermediate-term exposure is an MOE of 300 or 
lower. Results from the intermediate-term risk assessment indicate that 
the intermediate-term aggregate MOE is 819 for the most highly exposed 
child subgroup. Therefore, estimated aggregate (food + water + 
residential) exposure to halosulfuron-methyl are not of concern for 
intermediate-term aggregate exposure.
    4. Cumulative effects from substances with a common mechanism of 
toxicity. Section 408(b)(2)(D)(v) of FFDCA requires that, when 
considering whether to establish, modify, or revoke a tolerance, the 
Agency consider ``available information'' concerning the cumulative 
effects of a particular pesticide's residues and ``other substances 
that have a common mechanism of toxicity.''
    Unlike other pesticides for which EPA has followed a cumulative 
risk approach based on a common mechanism of toxicity, EPA has not made 
a common mechanism of toxicity finding as to halosulfuron-methyl and 
any other substances and 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 policy statements 
released by EPA's OPP concerning common mechanism determinations and 
procedures for cumulating effects from substances found to have a 
common mechanism on EPA's website at https://www.epa.gov/pesticides/
cumulative/.

C. Safety Factor for Infants and Children

    1. In general. Section 408 of FFDCA 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-natal and post-natal 
toxicity and the completeness of the database on toxicity and exposure 
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 MOE analysis or 
through using UFs in calculating a dose level that poses no appreciable 
risk to humans.
    2. Conclusion. The Agency concludes that no special FQPA SF is 
necessary to protect the safety of infants and children in assessing 
halosulfuron-methyl exposure and risks because:
    i. There is no evidence of increased susceptibility of young rats 
in the reproduction study with halosulfuron-methyl. Although there is 
qualitative evidence of increased susceptibility in the prenatal 
developmental studies in rats and rabbits the Agency is regulating at 
the NOAEL of 50 mg/kg/day for acute dietary, short-term incidental oral 
and inhalation risk assessments and the NOAEL of 10 mg/kg/day for 
chronic dietary and intermediate-term incidental oral, dermal, and 
inhalation risk assessments. These endpoints are 5X and 25X lower, 
respectively, than the NOAEL of 250 mg/kg/day in the rat developmental 
study where alterations of the fetal nervous system were seen at 750 
mg/kg/day (LOAEL).
    ii. There are no residual uncertainties identified in the exposure 
databases. The dietary food exposure assessments may be refined using 
anticipated residues calculated from field trial data with any PCT 
information. Conservative ground and surface water modeling estimates 
have been used. The Agency's residential standard operating procedures 
(SOPs) are used to assess post-application exposure to children as well 
as incidental oral exposure of toddlers. These assessments will not 
underestimate the exposure and risks posed by halosulfuron-methyl.
    However, a 3X additional database UF will be used to address the 
data deficiency for the developmental neurotoxicity study. The 3X 
safety factor should be applied to all dietary and residential non-
dietary exposure scenarios. No FQPA SF is appropriate for halosulfuron-
methyl.

D. Aggregate Risks and Determination of Safety

    The Agency currently has two ways to estimate total aggregate 
exposure to a pesticide from food, drinking water, and residential 
uses. First, a screening assessment can be used, in which the Agency 
calculates drinking water levels of comparison (DWLOCs) which are used 
as a point of comparison against EECs. The DWLOC values are not 
regulatory standards for drinking water, but are theoretical upper 
limits on a pesticide's concentration in drinking water in light of 
total aggregate exposure to a pesticide in food and residential uses. 
In calculating a DWLOC, the Agency determines how much of the 
acceptable exposure (i.e., the PAD) is available for exposure through 
drinking water e.g., allowable chronic water exposure (mg/kg/day) = 
cPAD - (average food + residential exposure). This allowable exposure 
through drinking water is used to calculate a DWLOC.
    A DWLOC will vary depending on the toxic endpoint, drinking water 
consumption, and body weights. Default body weights and consumption 
values as used by the EPA's Office of Water are used to calculate 
DWLOCs: 2 liter (L)/70 kg (adult male), 2 L/60 kg (adult female), and 1 
L/10 kg (child). Different populations will have different DWLOCs. 
Generally, a DWLOC is calculated for each type of risk assessment used: 
Acute, short-term, intermediate-term, chronic, and cancer.
    When EECs for surface water and ground water are less than the 
calculated DWLOCs, OPP concludes with reasonable certainty that 
exposures to the pesticide in drinking water (when considered along 
with other sources of exposure for which OPP has reliable data) would 
not result in unacceptable levels of aggregate human health risk at

[[Page 51620]]

this time. Because OPP considers the aggregate risk resulting from 
multiple exposure pathways associated with a pesticide's uses, levels 
of comparison in drinking water may vary as those uses change. When new 
uses are added OPP reassesses the potential impacts of residues of the 
pesticide in drinking water as a part of the aggregate risk assessment 
process.
    More recently the Agency has used another approach to estimate 
aggregate exposure through food, residential, and drinking water 
pathways. In this approach, modeled surface and ground water EECs are 
directly incorporated into the dietary exposure analysis, along with 
food. This provides a more realistic estimate of exposure because 
actual body weights and water consumption from the CSFII are used. The 
combined food and water exposures are then added to estimated exposure 
from residential sources to calculate aggregate risks. The resulting 
exposure and risk estimates are still considered to be high end, due to 
the assumptions used in developing drinking water modeling inputs. This 
risk assessment for halosulfuron-methyl was conducted using this 
approach.
    1. Acute risk. Using the exposure assumptions discussed in this 
unit for acute exposure, the acute dietary exposure from food and water 
to halosulfuron-methyl will occupy 14% for females 13-50 years of age, 
the population subgroup of concern. EPA does not expect the aggregate 
exposure to exceed 100% of the aPAD, as shown in Table 2 of this unit:

 Table 2.--Aggregate Risk Assessment for Acute Exposure to Halosulfuron-
                                 methyl
------------------------------------------------------------------------
                                                       % aPAD  (Food and
        Population subgroup           aPAD  (mg/kg)          Water)
------------------------------------------------------------------------
Females 13 years and older                       0.17                14%
------------------------------------------------------------------------

    2. Chronic risk. Using the exposure assumptions described in this 
unit for chronic exposure, EPA has concluded that exposure to 
halosulfuron-methyl from food and water will utilize 2% or less of the 
cPAD for all population subgroups in DEEM\TM\ including the U.S. 
population, infants and children. There are no residential uses for 
halosulfuron-methyl that result in chronic residential exposure to 
halosulfuron-methyl. Based on the use pattern, chronic residential 
exposure to residues of halosulfuron-methyl is not expected. EPA does 
not expect the aggregate exposure to exceed 100% of the cPAD, as shown 
in Table 3 of this unit:


Table 3.--Aggregate Risk Assessment for Chronic (Non-Cancer) Exposure to
                           Halosulfuron-methyl
------------------------------------------------------------------------
                                                       % cPAD  (Food and
        Population subgroup          cPAD  mg/kg/day         Water)
------------------------------------------------------------------------
U.S. population                                  0.03                 1%
-----------------------------------
-----------------------------------
-----------------------------------
-----------------------------------
-----------------------------------
------------------------------------------------------------------------


    3. Short-term risk. Short-term aggregate exposure takes into 
account residential exposure plus chronic exposure to food and water 
(considered to be a background exposure level). Halosulfuron-methyl is 
currently registered for use(s) that could result in short-term 
residential exposure and the Agency has determined that it is 
appropriate to aggregate chronic food and water and short-term 
exposures for halosulfuron-methyl.
    Using the exposure assumptions described in this unit for short-
term exposures, EPA has concluded that food, water and residential 
exposures aggregated result in aggregate MOEs of 5,800 for the general 
U.S. population and 3,200 for children 3-5 years old for dermal, 
incidental oral, and inhalation exposures. These aggregate MOEs do not 
exceed the Agency's level of concern for aggregate exposure to food and 
residential uses. EPA does not expect short-term aggregate exposure to 
exceed the Agency's level of concern, as shown in Table 4 of this unit:

               Table 4.--Aggregate Risk Assessment for Short-Term Exposure to Halosulfuron-methyl
----------------------------------------------------------------------------------------------------------------
                                                      Aggregate MOE  (Food + Water   Aggregate Level of Concern
                 Population subgroup                         + Residential)                     (LOC)
----------------------------------------------------------------------------------------------------------------
U.S. population                                                              5,800                           300
----------------------------------------------------------------------------------------------------------------

[[Page 51621]]

Intermediate-term risk. Intermediate-term aggregate exposure takes into
methyl.Using the exposure assumptions described in
 this unit for intermediate-term exposures, EPA has
 concluded that food, water and residential
 exposures aggregated result in an aggregate MOE of
 819 for infants and children (the population
 subgroup of concern). This aggregate MOE does not
 exceed the Agency's level of concern for aggregate
 exposure to food, water and residential uses. EPA
 does not expect intermediate-term aggregate
 exposure to exceed the Agency's level of concern,
 as shown in Table 5 of this unit:3,L4,i1,s15,25,25
Children 3-5 years                                                             819                           300
----------------------------------------------------------------------------------------------------------------

    5. Aggregate cancer risk for U.S. population. Halosulfuron-methyl 
is classified as a ``Not Likely'' human carcinogen. Therefore, risk 
assessments to assess cancer risk were not conducted.
    6. Determination of safety. Based on these risk assessments, EPA 
concludes that there is a reasonable certainty that no harm will result 
to the general population, and to infants and children from aggregate 
exposure to halosulfuron-methyl residues.

V. Other Considerations

A. Analytical Enforcement Methodology

    Adequate enforcement methodology (example--gas chromatography) is 
available to enforce the tolerance expression. The method may be 
requested from: Chief, Analytical Chemistry Branch, Environmental 
Science Center, 701 Mapes Rd., Ft. Meade, MD 20755-5350; telephone 
number: (410) 305-2905; e-mail address: residuemethods@epa.gov.

B. International Residue Limits

    There is neither a Codex proposal, nor Canadian or Mexican maximum 
residue limits, for residues of halosulfuron-methyl in or on sweet 
potatoes. Therefore, harmonization is not an issue.

VI. Conclusion

    Therefore, the tolerance is established for residues of 
halosulfuron-methyl, methyl 5-[(4,6-dimethoxy-2-pyrimidinyl)amino] 
carbonylaminosulfonyl-3-chloro-1-methyl-1H-pyrazole-4-carboxylate, in 
or on sweet potato at 1.0 ppm.

VII. Objections and Hearing Requests

    Under section 408(g) of FFDCA, as amended by FQPA, any person may 
file an objection to any aspect of this regulation and may also request 
a hearing on those objections. The EPA procedural regulations which 
govern the submission of objections and requests for hearings appear in 
40 CFR part 178. Although the procedures in those regulations require 
some modification to reflect the amendments made to FFDCA by FQPA, EPA 
will continue to use those procedures, with appropriate adjustments, 
until the necessary modifications can be made. The new section 408(g) 
of FFDCA provides essentially the same process for persons to 
``object'' to a regulation for an exemption from the requirement of a 
tolerance issued by EPA under new section 408(d) of FFDCA, as was 
provided in the old sections 408 and 409 of FFDCA. However, the period 
for filing objections is now 60 days, rather than 30 days.

A. What Do I Need to Do to File an Objection or Request a Hearing?

    You must file your objection or request a hearing on this 
regulation in accordance with the instructions provided in this unit 
and in 40 CFR part 178. To ensure proper receipt by EPA, you must 
identify docket ID number OPP-2005-0165 in the subject line on the 
first page of your submission. All requests must be in writing, and 
must be mailed or delivered to the Hearing Clerk on or before October 
31, 2005.
    1. Filing the request. Your objection must specify the specific 
provisions in the regulation that you object to, and the grounds for 
the objections (40 CFR 178.25). If a hearing is requested, the 
objections must include a statement of the factual issues(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). 
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.
    Mail your written request to: Office of the Hearing Clerk (1900L), 
Environmental Protection Agency, 1200 Pennsylvania Ave., NW., 
Washington, DC 20460-0001. You may also deliver your request to the 
Office of the Hearing Clerk in Suite 350, 1099 14\th\ St., NW., 
Washington, DC 20005. The Office of the Hearing Clerk is open from 8 
a.m. to 4 p.m., Monday through Friday, excluding legal holidays. The 
telephone number for the Office of the Hearing Clerk is (202) 564-6255.
    2. Copies for the Docket. In addition to filing an objection or 
hearing request with the Hearing Clerk as described in Unit VII.A., you 
should also send a copy of your request to the PIRIB for its inclusion 
in the official record that is described in ADDRESSES. Mail your 
copies, identified by the docket ID number OPP-2005-0165, to: Public 
Information and Records Integrity Branch, Information Resources and 
Services Division (7502C), Office of Pesticide Programs, Environmental 
Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460-
0001. In person or by courier, bring a copy to the location of the 
PIRIB described in ADDRESSES. You may also send an electronic copy of 
your request via e-mail to: opp-docket@epa.gov. Please use an ASCII 
file format and avoid the use of special characters and any form of 
encryption. Copies of electronic objections and hearing requests will 
also be accepted on disks in WordPerfect 6.1/8.0 or ASCII file format. 
Do not include any CBI in your electronic copy. You may also submit an 
electronic copy of your request at many Federal Depository Libraries.

[[Page 51622]]

B. When Will the Agency Grant a Request for a Hearing?

    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 issues(s) in the manner sought 
by the requestor would be adequate to justify the action requested (40 
CFR 178.32).

VIII. Statutory and Executive Order Reviews

    This final rule establishes a time-limited tolerance under section 
408 of FFDCA. The Office of Management and Budget (OMB) has exempted 
these types of actions from review under Executive Order 12866, 
entitled Regulatory Planning and Review (58 FR 51735, October 4, 1993). 
Because this rule has been exempted from review under Executive Order 
12866 due to its lack of significance, this rule is not subject to 
Executive Order 13211, Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use (66 FR 28355, 
May 22, 2001). This final rule does not contain any information 
collections subject to OMB approval under the Paperwork Reduction Act 
(PRA), 44 U.S.C. 3501 et seq., or impose any enforceable duty or 
contain any unfunded mandate as described under Title II of the 
Unfunded Mandates Reform Act of 1995 (UMRA) (Public Law 104-4). Nor 
does it require any special considerations under Executive Order 12898, 
entitled Federal Actions to Address Environmental Justice in Minority 
Populations and Low-Income Populations (59 FR 7629, February 16, 1994); 
or OMB review or any Agency action under Executive Order 13045, 
entitled Protection of Children from Environmental Health Risks and 
Safety Risks (62 FR 19885, April 23, 1997). This action does not 
involve any technical standards that would require Agency consideration 
of voluntary consensus standards pursuant to section 12(d) of the 
National Technology Transfer and Advancement Act of 1995 (NTTAA), 
Public Law 104-113, section 12(d) (15 U.S.C. 272 note). Since 
tolerances and exemptions that are established on the basis of a FIFRA 
section 18 exemption under section 408 of FFDCA, such as the tolerance 
in this final rule, do not require the issuance of a proposed rule, the 
requirements of the Regulatory Flexibility Act (RFA) (5 U.S.C. 601 et 
seq.) do not apply. In addition, the Agency has determined that this 
action will not have a substantial direct effect on States, on the 
relationship between the national government and the States, or on the 
distribution of power and responsibilities among the various levels of 
government, as specified in Executive Order 13132, entitled Federalism 
(64 FR 43255, August 10, 1999). Executive Order 13132 requires EPA to 
develop an accountable process to ensure ``meaningful and timely input 
by State and local officials in the development of regulatory policies 
that have federalism implications.'' ``Policies that have federalism 
implications'' is defined in the Executive order to include regulations 
that have ``substantial direct effects on the States, on the 
relationship between the national government and the States, or on the 
distribution of power and responsibilities among the various levels of 
government.'' This final rule directly regulates growers, food 
processors, food handlers, and food retailers, not States. This action 
does not alter the relationships or distribution of power and 
responsibilities established by Congress in the preemption provisions 
of section 408(n)(4) of the FFDCA. For these same reasons, the Agency 
has determined that this rule does not have any ``tribal implications'' 
as described in Executive Order 13175, entitled Consultation and 
Coordination with Indian Tribal Governments (65 FR 67249, November 6, 
2000). Executive Order 13175, requires EPA to develop an accountable 
process to ensure ``meaningful and timely input by tribal officials in 
the development of regulatory policies that have tribal implications.'' 
``Policies that have tribal implications'' is defined in the Executive 
order to include regulations that have ``substantial direct effects on 
one or more Indian tribes, on the relationship between the Federal 
Government and the Indian tribes, or on the distribution of power and 
responsibilities between the Federal Government and Indian tribes.'' 
This rule will not have substantial direct effects on tribal 
governments, on the relationship between the Federal Government and 
Indian tribes, or on the distribution of power and responsibilities 
between the Federal Government and Indian tribes, as specified in 
Executive Order 13175. Thus, Executive Order 13175 does not apply to 
this rule.

IX. Congressional Review Act

    The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the 
Small Business Regulatory Enforcement Fairness Act of 1996, generally 
provides that before a rule may take effect, the agency promulgating 
the rule must submit a rule report, which includes a copy of the rule, 
to each House of the Congress and to the Comptroller General of the 
United States. EPA will submit a report containing this rule and other 
required information to the U.S. Senate, the U.S. House of 
Representatives, and the Comptroller General of the United States prior 
to publication of this final rule in the Federal Register. This final 
rule is not a ``major rule'' as defined by 5 U.S.C. 804(2).

List of Subjects in 40 CFR Part 180

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


    Dated: August 19, 2005.
Lois Rossi,
Director, Registration Division, Office of Pesticide Programs.

0
Therefore, 40 CFR chapter I is amended as follows:

PART 180--[AMENDED]

0
1. The authority citation for part 180 continues to read as follows:

    Authority: 21 U.S.C. 321(q), 346a and 371.

0
2. Section 180.479 is amended by revising the introductory text of 
paragraph (a)(1) and by adding text to paragraph (b) to read as 
follows:


Sec.  180.479  Halosulfuron-methyl; tolerances for residues.

    (a) * * * (1) 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 in the 
table in this unit.
* * * * *
    (b) Section 18 emergency exemptions. Time-limited tolerances are 
established for residues of halosulfuron methyl, methyl 5-[(4,6-
dimethoxy-2-pyrimidinyl)amino] carbonylaminosulfonyl-3-chloro-1-methyl-
1H-pyrazole-4-carboxylate, in connection with use of the pesticide 
under FIFRA section 18 emergency exemptions granted by EPA in or on the 
following commodity:

[[Page 51623]]



------------------------------------------------------------------------
                                                             Expiration/
                   Commodity                     Parts per    revocation
                                                  million        date
------------------------------------------------------------------------
Sweet potato..................................          1.0     12/31/08
------------------------------------------------------------------------

* * * * *

[FR Doc. 05-17204 Filed 8-30-05; 8:45 am]
BILLING CODE 6560-50-S