Document ID: EPA-HQ-OPP-2005-0270-0001
Agency: epa
Document Type: Rule
Title: Sulfosulfuron; Pesticide Tolerances for Emergency Exemptions
Posted Date: 2005-11-16T05:00Z

[Federal Register: November 16, 2005 (Volume 70, Number 220)]
[Rules and Regulations]               
[Page 69457-69464]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr16no05-16]                         

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[OPP-2005-0270; FRL-7740-1]

 
Sulfosulfuron; Pesticide Tolerances for Emergency Exemptions

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This regulation establishes time-limited tolerances for 
combined residues of sulfosulfuron and its metabolites in or on 
Bahiagrass, forage; Bahiagrass, hay; Bermudagrass, forage; 
Bermudagrass, hay; milk; fat (of cattle, goat, horse and sheep); meat 
(of cattle, goat, horse and sheep); and meat byproducts (of cattle, 
goat, horse and sheep). This action is in response to EPA's granting of 
emergency exemptions under section 18 of the Federal Insecticide, 
Fungicide, and Rodenticide Act (FIFRA) authorizing use of the pesticide 
on Bahiagrass and Bermudagrass pastures and hayfields. This regulation 
establishes maximum permissible levels for residues of sulfosulfuron in 
these food commodities. The tolerances will expire and are revoked on 
December 31, 2009.

DATES: This regulation is effective November 16, 2005. Objections and 
requests for hearings must be received on or before January 17, 2006.

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-2005-0270. All documents in the docket 
are listed in the EDOCKET index at http://www.epa.gov/edocket. Although 

listed in the index, some information is not publicly available, i.e., 
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: Libby Pemberton, Registration Division 
(7505C), Office of Pesticide Programs, Environmental Protection Agency, 
1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone 
number: (703) 308-9364; e-mail address: pemberton.libby@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 (http://www.epa.gov/edocket/), you may 

access this Federal Register document electronically through the EPA 
Internet under the ``Federal Register'' listings at http://www.epa.gov/fedrgstr/.
 A frequently updated electronic version of 40 CFR part 180 

is available on E-CFR Beta Site Two at http://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 combined residues of the 
herbicide sulfosulfuron, [1-(4,6-dimethoxypyrimidin-2yl)-3-[(2-
ethanesulfonyl-imidazo[1,2-a]pyridine-3-yl)sulfonyl]urea and 
metabolites converted to 2-(ethylsulfonyl)-imidazo[1,2-a]pyridine 
(calculated as sulfosulfuron), in or on Bahiagrass, forage at 11 parts 
per million (ppm); Bahiagrass, hay at 40 ppm; Bermudagrass, forage at 
11 ppm; Bermudagrass, hay at 40 ppm; milk at 0.02 ppm; fat (of cattle, 
goat, horse and sheep) at 0.04 ppm; meat (of cattle, goat, horse and 
sheep) at 0.02 ppm; and meat byproducts (cattle, goat, horse and sheep) 
at 0.50 ppm. These tolerances will expire and are revoked on December 
31, 2009. EPA will publish a document in the Federal Register to remove 
the revoked tolerances from the Code of Federal Regulations.
    Section 408(l)(6) of the FFDCA requires EPA to establish a time-
limited tolerance or exemption from the requirement for a tolerance for 
pesticide chemical residues in food that will result from the use of a 
pesticide under an emergency exemption granted by EPA under section 18 
of FIFRA. Such tolerances can be established without providing notice 
or period for public comment. EPA does not intend for its actions on 
section 18 related tolerances to set binding precedents for the 
application of section 408 of the FFDCA and the new safety standard to 
other tolerances and exemptions. Section 408(e) of the 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 the FFDCA allows EPA to establish a 
tolerance (the legal limit for a pesticide chemical residue in or on a 
food) only if EPA determines that the tolerance is ``safe.'' Section 
408(b)(2)(A)(ii) of the 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 the 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

[[Page 69458]]

children from aggregate exposure to the pesticide chemical residue. . 
..''
    Section 18 of the 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 Sulfosulfuron on Bahia and Bermudagrass 
Pastures and Hayfields and FFDCA Tolerances

    Alabama, Georgia, Louisiana, Mississippi and Oklahoma indicate 
that, with the removal of imazapic from the hay and pasture market, 
there is no available control for Johnsongrass in Bahiagrass and/or 
Bermudagrass pasture and hayfields. Growers may experience significant 
losses without sulfosulfuron to control Johnsongrass. Johnsongrass 
reduces Bermudagrass hay quality and value. Additionally, under 
stressful conditions such as drought, frost or trampling, Johnsongrass 
may produce prussic acid which is toxic to livestock. Imazapic, the 
herbicide previously used to control Johnsongrass, was removed from the 
pasture and hay market in January 2004 resulting in the need for an 
emergency replacement. EPA has authorized under FIFRA section 18 the 
use of sulfosulfuron on Bahiagrass and Bermudagrass pasture and 
hayfields for control of Johnsongrass in Alabama, Georgia, Louisiana, 
Mississippi, and Oklahoma. 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 sulfosulfuron in or on 
forage and hay associated with both Bermudagrass and Bahiagrass, as 
well as on various animal commodities for which residues may be 
present. In doing so, EPA considered the safety standard in section 
408(b)(2) of the FFDCA, and EPA decided that the necessary tolerances 
under section 408(l)(6) of the FFDCA would be consistent with the 
safety standard and with FIFRA section 18. Consistent with the need to 
move quickly on the emergency exemptions in order to address an urgent 
non-routine situation and to ensure that the resulting food is safe and 
lawful, EPA is issuing these tolerances without notice and opportunity 
for public comment as provided in section 408(l)(6) of the FFDCA. 
Although these tolerances will expire and are revoked on December 31, 
2009, under section 408(l)(5) of the FFDCA, residues of the pesticide 
not in excess of the amounts specified in the tolerances remaining in 
or on forage and hay associated with both Bermudagrass and Bahiagrass, 
as well as on the various associated animal commodities 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 these tolerances at the time of that 
application. EPA will take action to revoke these tolerances earlier if 
any experience with, scientific data on, or other relevant information 
on this pesticide indicate that the residues are not safe.
    Because these tolerances are being approved under emergency 
conditions, EPA has not made any decisions about whether sulfosulfuron 
meets EPA's registration requirements for use on Bermudagrass or 
Bahiagrass or whether permanent tolerances for this use would be 
appropriate. Under these circumstances, EPA does not believe that these 
tolerances serve as a basis for registration of sulfosulfuron by a 
State for special local needs under FIFRA section 24(c). Nor do these 
tolerances serve as the basis for any State other than Alabama, 
Georgia, Louisiana, Mississippi, and Oklahoma to use this pesticide on 
these crops under section 18 of FIFRA without following all provisions 
of EPA's regulations implementing FIFRA section 18 as identified in 40 
CFR part 166. For additional information regarding the emergency 
exemption for sulfosulfuron, 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 the 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 the 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 
sulfosulfuron and to make a determination on aggregate exposure, 
consistent with section 408(b)(2) of the FFDCA, for time-limited 
tolerances for combined residues of sulfosulfuron and its metabolites 
(calculated as sulfosulfuron) in or on Bahiagrass, forage at 11 ppm; 
Bahiagrass, hay at 40 ppm; Bermudagrass, forage at 11 ppm; 
Bermudagrass, hay at 40 ppm; milk at 0.02 ppm; fat (of cattle, goat, 
horse and sheep) at 0.04 ppm; meat (of cattle, goat, horse and sheep) 
at 0.02 ppm; and meat byproducts (cattle, goat, horse and sheep) at 
0.50 ppm. EPA's assessment of the dietary exposures and risks 
associated with establishing these tolerances 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 intraspecies differences.
    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 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. 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

[[Page 69459]]

(e.g., risk is expressed as 1 x 10-6 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 sulfosulfuron used for human risk assessment is shown in 
the following Table 1:

    Table 1.--Summary of Toxicological Dose and Endpoints for Sulfosulfuron for Use in Human Risk Assessment
----------------------------------------------------------------------------------------------------------------
                                                                  Hazard and Exposure
          Exposure Scenario               Dose Used in Risk        Based Special FQPA    Study and Toxicological
                                            Assessment, UF           Safety Factor               Effects
----------------------------------------------------------------------------------------------------------------
Acute Dietary; all populations         A dose and endpoint was  NA                       NA
                                        not selected for acute
                                        dietary risk
                                        assessment because
                                        there were no effects
                                        attributable to a
                                        single dose (exposure)
                                        in the oral toxicology
                                        studies including
                                        developmental toxicity
                                        studies in the rat and
                                        the rabbit and an
                                        acute neurotoxicity
                                        study in the rat.
--------------------------------------
Chronic Dietary all populations        NOAEL= 24 mg/kg/day      FQPA SF = 1              Chronic toxicity/
                                       UF\1\ = 100............  cPAD = cRfD / FQPA SF..   carcinogenicity - rat;
                                       Chronic RfD = 0.24 mg/   cPAD = 0.24 mg/kg/day..  LOAEL = 244.2 mg/kg/day
                                        kg/day.                                           based on urinary tract
                                                                                          pathology,abnormal
                                                                                          cyrtals and urinary
                                                                                          calculi (both sexes);
                                                                                          mineraliztion in
                                                                                          heart, lung, pancreas,
                                                                                          and skeletal muscles
                                                                                          (male)
--------------------------------------
Short-,Intermediate- Long-Term Dermal  No dermal or systemic    NA                       NA
                                        toxicity was seen
                                        following repeated
                                        dermal application at
                                        the limit dose in a 21-
                                        day dermal toxicity
                                        study in rats.
                                        Therefore, this risk
                                        assessment is not
                                        required.
--------------------------------------
Inhalation (Any time period)           Based on the low acute   NA                       NA
                                        inhalation toxicity
                                        (Category IV; no
                                        mortality at 3 mg/L),
                                        the formulation of the
                                        product as wettable
                                        granules, and the low
                                        application rates for
                                        the proposed use
                                        patterns ranging from
                                        25 - 70 g a.i./hectare
                                        (10-28 g a.i./acre),
                                        there is minimal
                                        concern for potential
                                        inhalation exposure
                                        and risk. Therefore, a
                                        separate inhalation
                                        risk assessment is not
                                        required.
--------------------------------------
Cancer                                 Likely human carcinogen  NA                       NA
                                        - Q1* = 1.03 x 10-3
                                        (mg/kg/day) -1 in
                                        human equivalents
                                        (converted from
                                        animals to humans by
                                        use of the BW3/4's
                                        scaling factor)
----------------------------------------------------------------------------------------------------------------
\1\ uncertainty factor; 10x for intraspecies variation and 10x for interspecies variation
* The reference to the FQPA SF refers to any additional SF retained due to concerns unique to the FQPA.

B. Exposure Assessment

    1. Dietary exposure from food and feed uses. Tolerances have been 
established (40 CFR 180.552) for the combined residues of 
sulfosulfuron, in or on wheat grain, forage, hay, staw and related milk 
and meat commodities. Risk assessments were conducted by EPA to assess 
dietary exposures from sulfosulfuron 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. As summarized in Table 1 (above), EPA's review has 
concluded that sulfosulfuron has low acute oral, dermal, and inhalation 
toxicity. It is non-irritating to skin and slightly irritating to eyes. 
It is not a skin sensitizer. EPA has not selected toxicity endpoints 
for acute exposure reflecting the low hazard associated with acute 
exposure to this chemical.
    ii. Chronic exposure and cancer assessement. Chronic and cancer 
dietary risk assessments were conducted using LifelineTM 
(ver. 2.00) and the Dietary Exposure Evaluation Model - Food 
Consumption Intake Database (DEEM-FCIDTM, ver. 1.30) models. 
Both of these models use food consumption data from the USDA's 
Continuing Surveys of Food Intakes by Individuals (CSFII); 1994-1996 
and 1998).
    The chronic and cancer analyses assumed tolerance level residues, 
100% crop treated, and DEEMTM (ver. 7.76) default processing 
factors. The LifelineTM chronic exposure estimates were <1% 
cPAD for all population subgroups (therefore less than EPA's level of 
concern). The LifelineTM lifetime cancer risk for the U.S. 
population is 2.0 x 10-7 (therefore less than EPA's level of 
concern for the general U.S. population). DEEM-FCIDTM 
resulted in chronic (< 1% cPAD; children 1-2 years old were the most 
highly exposed subgroup) and cancer

[[Page 69460]]

(2.1 x 10-7) exposure estimates similar to 
LifelineTM.
    In accordance with the Agency's Proposed Guidelines for 
Carcinogenic Risk Assessment (April 10, 1996), EPA has classified 
sulfosulfuron as a likely human carcinogen. The weight-of-evidence for 
this classification includes: (1) Occurrence of rare transitional cell 
papilloma (benign tumors) and carcinoma of the urinary bladder in 
female rats; (2) occurrence of rare benign mesenchymal tumors of the 
urinary bladder in high dose male as well as renal adenomas in female 
and possibly male mice, and (3) the relevancy of the observed tumors to 
human exposure.
    EPA utilizes a linear low-dose approach (Q1*) for human risk 
characterization and extrapolation of risk should be based on the 
incidence of benign mesenchymal tumors in male mice. The rat 
transitional cell tumors and mouse renal adenomas were not used because 
of their low incidence. This extrapolation, rather than an MOE 
approach, is supported by the lack of sufficient data to characterize 
the mechanism of carcinogenicity. The unit risk, Q1* (in milligrams/
kilograms/day) (mg/kg/day)-1 of sulfosulfuron based upon 
male mouse urinary bladder mesenchymal tumor rates is 1.03 x 
10-3 (mg/kg/day)-1 in human equivalents.
    iii. Anticipated residue and percent crop treated (PCT) 
information. EPA did not use PCT information in this assessment. As 
stated above, EPA has performed a conservative assessment utilizing an 
assumption of 100% crop treated, and 100% tolerance levels detected, 
for the associated commodities.
    2. Dietary exposure from drinking water. The Agency lacks 
sufficient monitoring exposure data to complete a comprehensive dietary 
exposure analysis and risk assessment for sulfosulfuron 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 sulfosulfuron.
    The Agency uses the Generic Estimated Environmental Concentration 
(GENEEC)or the Pesticide Root Zone/Exposure Analysis Modeling System 
(PRZM/EXAMS) to estimate pesticide concentrations in surface water and 
Screening Concentrations in Groundwater (SCI-GROW), which predicts 
pesticide concentrations in ground water. In general, EPA will use 
GENEEC (a Tier 1 model) before using PRZM/EXAMS (a Tier 2 model) for a 
screening-level assessment for surface water. The GENEEC model is a 
subset of the PRZM/EXAMS model that uses a specific high-end runoff 
scenario for pesticides. GENEEC incorporates a farm pond scenario, 
while PRZM/EXAMS incorporate an index reservoir environment in place of 
the previous pond scenario. 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. The primary use of these models by the Agency at this 
stage is to provide a coarse screen for sorting out pesticides for 
which it is highly unlikely that drinking water concentrations would 
ever exceed human health levels of concern.
    Since the models used are considered to be screening tools in the 
risk assessment process, the Agency does not use estimated 
environmental concentrations (EECs) from these models to quantify 
drinking water exposure and risk as a %RfD or %PAD. Instead, drinking 
water levels of comparison (DWLOCs) are calculated and used as a point 
of comparison against the model estimates of a pesticide's 
concentration in water. DWLOCs are theoretical upper limits on a 
pesticide's concentration in drinking water in light of total aggregate 
exposure to a pesticide in food, and from residential uses. Since 
DWLOCs address total aggregate exposure to sulfosulfuron they are 
further discussed in the aggregate risk sections below.
    Based on the GENEEC and SCI-GROW models the EECs of sulfosulfuron 
for acute exposures are estimated to be 0.66 parts per billion (ppb) 
for surface water and 1.9 ppb for ground water. The EECs for chronic 
exposures are estimated to be 1.73 ppb for surface water and 0.295 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).
    There are no residential uses of sulfosulfuron that are expected to 
result in residential handler exposure. However, the commercial use of 
sulfosulfuron on residential and recreational turf may lead to post 
application exposure in individuals. EPA has performed a cancer risk 
assessment for adults and children based on post application 
residential exposure.
    Cancer risk for residential adults was calculated based on high and 
low activity. For high-exposure activity, a Transfer Coefficient (Tc) 
of 1,000 cm2/hr (1 hr) was used and for low-exposure 
activity, a Tc of 500 cm2/hr (1 hr) was used.
    EPA built several conservative assumptions into the assessment of 
residential cancer risk. These include using 50 years of exposure and 
an estimated 20% (default) of dislodgeable foliar residues (DFR) from 
the turf, which is derived from the maximum application rate. An 
average of 14 days of DFRs was used for this cancer assessment; this 
would be considered a 10% decrease each day (from dilution by rain, and 
mowing of the grass) of the 20% residue for at least 14 days, and then 
taking the mean value of this 14-day exposure.
    The Lifetime Average Daily Dose (LADD) = 6.0 x 10-5 mg/
kg/day for a Tc =1,000 cm2/hr (high-exposure activity for 1 
hour) and for a Tc = 500 cm2/hr (low-exposure activity for 1 
hour) is equal to 3.0 x 10-5 mg/kg/day.
    The estimated cancer risk for adults on day zero, based on high-
exposure activity for 1 hour (Tc =1,000 cm2/hr) is estimated 
to be 1.2 x 10-7. For low-exposure activity (Tc = 500 
cm2/hr), the risk is estimated to be 6.0 x 10-8.
    Although it is likely that toddlers would also be exposed to 
sulfosulfuron from incidental ingestion of grass, soil, or hand-to-
mouth transfer, no relevant oral toxicological endpoints have been 
identified by EPA. Therefore, to address the short-term residential 
risk to children from incidental exposure, for the purposes of this 
assessment only, EPA used the NOAEL of 24mg/kg/day from the combined 
chronic toxicity/carcinogenicity study in rats. This NOAEL is 
considered conservative and health protective for this assessment 
because it represents the lowest NOAEL in the most sensitive species 
(the basis for the cRfD).
    Postapplication inhalation exposure is considered to be negligible. 
However, non-dietary, incidental ingestion of residues from treated 
turfgrass and ingestion of contaminated soil are possible.
    As a conservative measure, the exposure and risk estimates for four 
residential exposure scenarios are assessed for the day of application 
(day zero) because it is assumed that toddlers could contact the lawn 
immediately after application. Chronic exposure is not expected (i.e., 
these activities are

[[Page 69461]]

not expected to occur continuously for more than 30 days).
    Children's estimated risk from oral hand-to-mouth activities on 
treated lawns is estimated to result in a short-term MOE of 1,700. 
Children's estimated risk from oral object-to-mouth (turfgrass) from 
treated lawns is estimated to result in a short-term MOE of 6,800. 
Children's estimated risk from incidental ingestion of soil from 
treated lawns is estimated to result in a short-term MOE of 510,000. 
Since short-term MOEs are above 100, they do not exceed EPA's level of 
concern. Chronic or long-term exposure is not expected.
    While considered unlikely, if a toddler were to experience exposure 
from all of these sources at the same time, the combined incidental 
oral exposure would be 0.018 mg/kg/day. This combined exposure results 
in an estimated MOE of 1,400, which does not exceed EPA's level of 
concern.
    4. Cumulative effects from substances with a common mechanism of 
toxicity. Section 408(b)(2)(D)(v) of the 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 sulfosulfuron and any 
other substances and sulfosulfuron 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 sulfosulfuron 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 Office of 
Pesticide Programs concerning common mechanism determinations and 
procedures for cumulating effects from substances found to have a 
common mechanism on EPA's website at http://www.epa.gov/pesticides/cumulative/
.

C. Safety Factor for Infants and Children

    1. In general. Section 408 of the 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 prenatal and postnatal 
toxicity and the completeness of the data base 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 uncertainty (safety) factors in calculating a dose level 
that poses no appreciable risk to humans.
    2. Developmental reproductive toxicity studies. The results of the 
2-generation reproduction and developmental toxicity studies indicated 
that sulfosulfuron is not a developmental or reproductive toxicant. The 
acute and subchronic neurotoxicity studies showed that sulfosulfuron is 
not neurotoxic. Sulfosulfuron is rapidly excreted, primarily 
unmetabolized. Excretion at low dose occurred primarily in the urine, 
whereas at high dose, a large percentage of the administered dose was 
excreted in the feces. Sulfosulfuron was not retained in tissues to any 
significant extent.
    3. Conclusion. There is a complete toxicity data base for 
sulfosulfuron and exposure data are complete or are estimated based on 
data that reasonably accounts for potential exposures. EPA has 
determined that the 10X safety factor to protect infants and children 
should be removed. The FQPA factor is removed because the developmental 
and reproductive toxicity data did not indicate increased 
susceptibility of rats or rabbits to in utero and/or postnatal 
exposure. Any detectable residues in food or drinking water would be 
expected at low levels since application rates are low. There are 
currently no registered homeowner uses for sulfosulfuron. Finally, 
concern for post-application exposure to infants and children from 
commercial application of the pesticide is tempered by the low acute 
oral, dermal, and inhalation toxicity of this pesticide.

D. Aggregate Risks and Determination of Safety

    To estimate total aggregate exposure to a pesticide from food, 
drinking water, and residential uses, the Agency calculates DWLOCs 
which are used as a point of comparison against the model estimates of 
a pesticide's concentration in water (EECs). DWLOC values are not 
regulatory standards for drinking water. DWLOCs 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 + chronic non-dietary, non-occupational 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 EPA's Office of Water are used to calculate DWLOCs: 2 
liter (L)/70 kg (adult male), 2L/60 kg (adult female), and 1L/10 kg 
(child). Default body weights and drinking water consumption values 
vary on an individual basis. This variation will be taken into account 
in more refined screening-level and quantitative drinking water 
exposure assessments. 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, EPA concludes with reasonable certainty that 
exposures to sulfosulfuron in drinking water (when considered along 
with other sources of exposure for which EPA has reliable data) would 
not result in unacceptable levels of aggregate human health risk at 
this time. Because EPA considers the aggregate risk resulting from 
multiple exposure pathways associated with a pesticide's uses, levels 
of comparison in drinking water may vary as those uses change. If new 
uses are added in the future, EPA will reassess the potential impacts 
of sulfosulfuron on drinking water as a part of the aggregate risk 
assessment process.
    1. Acute risk. As discussed earlier, sulfosulfuron has low acute 
oral, dermal, and inhalation toxicity. It is non-irritating to skin, 
slightly irritating to eyes and is not a skin sensitizer. Endpoints for 
risk assessment through exposure via the acute dietary, dermal, 
inhalation and incidental oral routes were not identified; therefore, 
acute, short- and intermediate-term dermal and inhalation risk were not 
concerns.
    2. Chronic risk. Chronic and cancer aggregate risk assessments were 
performed for adults, while short-term and chronic aggregate risk 
assessments were performed for children. Using the exposure assumptions 
described in this unit for chronic exposure, EPA has concluded that 
exposure to sulfosulfuron from food will utilize < 1% of the cPAD for 
all population subgroups, including infants and children, young 
children, young adults, females of childbearing age and for the overall 
U.S. population. Based the use

[[Page 69462]]

pattern, chronic residential exposure to residues of sulfosulfuron is 
not expected. In addition, despite the potential for chronic dietary 
exposure to sulfosulfuron in drinking water, after calculating DWLOCs 
and comparing them to conservative model EECs of sulfosulfuron in 
surface water and ground water, EPA does not expect the aggregate 
exposure to exceed 100% of the cPAD, as shown in the following Table 2:

             Table 2.--Aggregate Risk Assessment for Chronic (Non- Cancer) Exposure to Sulfosulfuron
----------------------------------------------------------------------------------------------------------------
                                                   Chronic    Max Chronic     Ground      Surface
                                    cPAD (mg/kg/     Food        Water        Water        Water       Chronic
            Population                  day)       Exposure   Exposure\1\     EEC\2\       EEC\2\      DWLOC\3\
                                                 (mg/kg/day)  (mg/kg/day)     (ppb)        (ppb)        (ppb)
----------------------------------------------------------------------------------------------------------------
General U.S. population                      NA     0.000206         0.24           NA           NA        8,400
-----------------------------------
NA                                         0.24           NA           NA        0.295         1.73           NA
-----------------------------------
All infants (< 1 year old)                    NA     0.000286         0.24           NA           NA        2,400
-----------------------------------
Children (1-2 years old)                     NA     0.000900         0.24           NA           NA        2,400
-----------------------------------
Children (3-5 years old)                     NA     0.000636         0.24           NA           NA        2,400
-----------------------------------
Children (6-12 years old)                    NA     0.000387         0.24           NA           NA        2,400
-----------------------------------
Youth (13-19 years old)                      NA     0.000182         0.24           NA           NA        7,200
-----------------------------------
Adults (20-49 years old)                     NA     0.000124         0.24           NA           NA        8,400
-----------------------------------
Adults (50 + years old)                      NA     0.000114         0.24           NA           NA        8,400
-----------------------------------
Females (13-49 years old)                    NA     0.000123         0.24           NA           NA        7,200
----------------------------------------------------------------------------------------------------------------
\1\ Maximum chronic water exposure (mg/kg/day) = cPAD (mg/kg/day) - chronic food exposure from DEEM (mg/kg/day);
  no res. exp.
\2\ FIRST and SCI-GROW modeling EECs (Tier 1)
\3\ DWLOC([mu]g/L) = (allowable water exposure (mg/kg/day) x body weight (kg) x 1,000 [mu]g/mg) / (water
  consumption (liters))

    3. Short-term risk. The short-term aggregate risk takes into 
account the exposure from potential residential sources in addition to 
average dietary residues from food and drinking water. The short-term 
aggregate risk assessment was performed for children only, since an 
endpoint for dermal risk assessment was not identified. The resulting 
short-term DWLOC is 2,200 ppb and is not of concern because it exceeds 
the EECs for sulfosulfuron. Short-term aggregate risks are presented in 
the following Table 3:

                                               Table 3.--Short-Term Aggregate Risk and DWLOC Calculations
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                      Short-Term Scenario
                                      ------------------------------------------------------------------------------------------------------------------
                                                                         Average                  Aggregate   Allowable                          Short-
              Population               NOAEL mg/    Target      Max        Food    Residential    MOE (food     Water      Ground    Surface      Term
                                         kg/day      MOE      Exposure   Exposure  Exposure mg/      and       Exposure  Water EEC  Water EEC    DWLOC
                                                             mg/kg/day  mg/kg/day     kg/day    residential)  mg/kg/day    (ppb)      (ppb)      (ppb)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Child                                         24        100       0.24    0.00090       0.018         1,270    0.221100      0.295       1.73      2,200
--------------------------------------------------------------------------------------------------------------------------------------------------------

    4. Intermediate-term risk. Intermediate-term aggregate exposure 
takes into account non-dietary, non-occupational exposure plus chronic 
exposure to food and water (considered to be a background exposure 
level). Although residential exposure could occur with the use of 
sulfosulfuron, no toxicological effects have been identified for 
intermediate-term toxicity. Therefore, the aggregate risk is the sum of 
the risk from food and water, which were previously addressed.
    5. Aggregate cancer risk for U.S. population. The cancer aggregate 
risk assessment considered exposure from food, water and residential 
sources. EPA performs cancer assessments for only the general U.S. 
population. The cancer dietary analyses assumed tolerance level 
residues, 100% crop treated, and DEEM default processing factors. The 
Lifeline\TM\ lifetime cancer risk for the U.S. population is 2.0 x 
10-7 and is therefore less than EPA's level of concern. 
Residential cancer risk was estimated for adults only. The aggregate 
cancer risk DWLOC of 25 ppb exceeds EECs for sulfosulfuron and does not 
result in a concern.
    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 sulfosulfuron 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.

[[Page 69463]]

B. International Residue Limits

    There is neither a Codex proposal, nor Canadian or Mexican maximum 
residue limits, for residues of sulfosulfuron in or on grasses. 
Therefore, harmonization is not an issue for this tolerance action.

C. Conditions

    No conditions are placed on these time-limited tolerances.

VI. Conclusion

    Therefore, tolerances are established for combined residues of 
sulfosulfuron, 1-(4,6-dimethoxypyrimidin-2yl)-3-[(2-ethanesulfonyl-
imidazo[1,2-a]pyridine-3-yl)sulfonyl]urea and metabolites converted to 
2-(ethylsulfonyl)-imidazo[1,2-a]pyridine (calculated as sulfosulfuron), 
in or on Bermudagrass, forage at 11 ppm; Bermudagrass, hay at 40 ppm; 
Bahiagrass, forage at 11 ppm; Bahiagrass, hay at 40 ppm; milk at 0.02 
ppm; fat (of cattle, goat, horse and sheep) at 0.04 ppm; meat (of 
cattle, goat, horse and sheep) at 0.02 ppm; and meat byproducts 
(cattle, goat, horse and sheep) at 0.50 ppm.

VII. Objections and Hearing Requests

    Under section 408(g) of the FFDCA, as amended by the 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 
the FFDCA by the FQPA, EPA will continue to use those procedures, with 
appropriate adjustments, until the necessary modifications can be made. 
The new section 408(g) of the 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 the FFDCA, as was provided in the old sections 408 and 409 of the 
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-2005-0270 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 January 
17, 2006.
    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 issue(s) on which a 
hearing is requested, the requestor's contentions on such issues, and a 
summary of any evidence relied upon by the objector (40 CFR 178.27). 
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.1., 
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-2005-0270, to: 
Public Information and Records Integrity Branch, Information Technology 
and Resource Management 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.

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 issue(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 time-limited tolerances under section 
408 of the FFDCA. The Office of Management and Budget (OMB) has 
exempted these types of actions from review under Executive Order 
12866, entitled Regulatory Planning and Review (58 FR 51735, October 4, 
1993). 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 the FFDCA, such as the 
tolerances in this final rule, do not require the issuance of a 
proposed rule, the

[[Page 69464]]

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: November 7, 2005.
Donald R. Stubbs,
Acting 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 180.552 is amended by adding text to paragraph (b) to read 
as follows:

Sec.  180.552  Sulfosulfuron; pesticide tolerances.

     * * * * *
    (b) Section 18 emergency exemptions. Time-limited tolerances are 
established for the combined residues of the herbicide sulfosulfuron, 
1-(4,6-dimethoxypyrimidin-2-yl)-3-[(2-ethanesulfonyl-imidazo[1,2-
a]pyridine-3-yl)sulfonyl]urea and metabolites converted to 2-
(ethylsulfonyl)-imidazo[1,2-a]pyridine (calculated as sulfosulfuron) in 
connection with use of the pesticide under section 18 emergency 
exemptions granted by EPA. The tolerances are specified in the 
following table. The tolerances will expire on the dates specified in 
the table.

------------------------------------------------------------------------
                                                             Expiration/
                   Commodity                     Parts per    revocation
                                                  million        date
------------------------------------------------------------------------
Bahiagrass, forage............................           11     12/31/09
Bahiagrass, hay...............................           40     12/31/09
Bermudagrass, forage..........................           11     12/31/09
Bermudagrass, hay.............................           40     12/31/09
Cattle, fat...................................         0.04     12/31/09
Cattle, meat..................................         0.02     12/31/09
Cattle, meat byproducts.......................         0.50     12/31/09
Goat, fat.....................................         0.04     12/31/09
Goat, meat....................................         0.02     12/31/09
Goat, meat byproducts.........................         0.50     12/31/09
Horse, fat....................................         0.04     12/31/09
Horse, meat...................................         0.02     12/31/09
Horse, meat byproducts........................         0.50     12/31/09
Milk..........................................         0.02     12/31/09
Sheep, fat....................................         0.04     12/31/09
Sheep, meat...................................         0.02     12/31/09
Sheep, meat byproducts........................         0.50     12/31/09
------------------------------------------------------------------------

* * * * *

[FR Doc. 05-22699 Filed 11-15-05; 8:45 am]

BILLING CODE 6560-50-S