[Federal Register Volume 67, Number 233 (Wednesday, December 4, 2002)]
[Rules and Regulations]
[Pages 72104-72110]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-30472]


=======================================================================
-----------------------------------------------------------------------

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[OPP-2002-0005; FRL-7279-5]


Pyrithiobac Sodium (sodium 2-chloro-6-[(4,6-dimethoxypyrimidin-2-
yl)thio]benzoate); Pesticide Tolerance

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: This regulation establishes a tolerance for residues of 
pyrithiobac sodium (sodium 2-chloro-6-[(4,6-dimethoxypyrimidin-2-
yl)thio]benzoate) in or on cotton, undelinted seed and cotton gin 
byproducts. DuPont Agricultural Products, Wilmington, DE requested this 
tolerance under the Federal Food, Drug, and Cosmetic Act (FFDCA), as 
amended by the Food Quality Protection Act (FQPA) of 1996.

DATES: This regulation is effective December 4, 2002. Objections and 
requests for hearings, identified by docket ID number OPP-2002-0005, 
must be received on or before February 3, 2003.

ADDRESSES: Written objections and hearing requests may be submitted by 
mail, in person, or by courier. Please follow the detailed instructions 
for each method as provided in Unit VI. of the SUPPLEMENTARY 
INFORMATION. To ensure proper receipt by EPA, your objections and 
hearing requests must identify docket ID number OPP-2002-0005 in the 
subject line on the first page of your response.

FOR FURTHER INFORMATION CONTACT: By mail: James A. Tompkins, Product 
Manager (PM) 25, Registration Division 7505C, Office of Pesticide 
Programs, Environmental Protection Agency, 1200 Pennsylvania Ave., NW., 
Washington, DC 20460; telephone number: (703) 305-5697; e-mail address: 
[email protected].

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this Action Apply to Me?

    You may be affected by this action if you are an agricultural 
producer, food manufacturer, or pesticide manufacturer. Potentially 
affected categories and entities may include, but are not limited to:

------------------------------------------------------------------------
                                                          Examples of
           Categories                 NAICS codes         potentially
                                                       affected entities
------------------------------------------------------------------------
Industry                          111                 Crop production
                                  112                 Animal production
                                  311                 Food manufacturing
                                  32532               Pesticide
                                                       manufacturing
------------------------------------------------------------------------

    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 the table could also be 
affected. The North American Industrial Classification System (NAICS) 
codes have been provided to assist you and others in determining 
whether or not this action might apply to certain entities. If you have 
questions regarding the applicability of this action to a particular 
entity, consult the person listed under FOR FURTHER INFORMATION 
CONTACT.

B. How Can I Get Additional Information, Including Copies of this 
Document and Other Related Documents?

    1. Docket. EPA has established an official public docket for this 
action under docket identification (ID) number OPP-2002-0005. The 
official public docket consists of the documents specifically 
referenced in this action, any public comments received, and other 
information related to this action. Although a part of the official 
docket, the public docket does not include Confidential Business 
Information (CBI) or other information whose disclosure is restricted 
by statute. The official public docket is the collection of materials 
that is available for public viewing at the Public Information and 
Records Integrity Branch (PIRIB), Rm. 119, Crystal Mall 2, 
1921 Jefferson Davis Hwy., 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.
    2. Electronic access. 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 at http://www.access.gpo.gov/nara/cfr/cfrhtml_00/Title_40/4 0cfr180--00.html, a 
beta site currently under development. To access the OPPTS Harmonized 
Guidelines referenced in this document, go directly to the guidelines 
at http://www.epa.gov/opptsfrs/home/guidelin.htm.
    An electronic version of the public docket is available through 
EPA's electronic public docket and comment system, EPA Dockets. You may 
use EPA Dockets at http://www.epa.gov/edocket/ to submit or view public 
comments, access the index listing of the contents of the official 
public docket, and to access those documents in the public docket that 
are available electronically. Although not all docket materials may be 
available electronically, you may still access any of the publicly 
available docket materials through the docket facility identified in 
Unit I.B.1. Once in the system, select ``search,'' then key in the 
appropriate docket ID number.

II. Background and Statutory Findings

    In the Federal Register of September 24, 1997 (62 FR 49979) (FRL-
5745-8), EPA issued a notice pursuant to section 408 of the FFDCA, 21 
U.S.C. 346a, as amended by the FQPA of 1996 (Public Law 104-170), 
announcing the filing of a pesticide petition PP 4F4391 by DuPont 
Agricultural Products, Wilmington, DE. This notice included a summary 
of the petition prepared by DuPont Agricultural Products, the 
registrant. There were no comments received in response to the notice 
of filing.
    The petition requested that 40 CFR 180.487 be amended by 
establishing a tolerance for residues of the herbicide pyrithiobac 
sodium, (sodium 2-chloro-6-[(4,6-dimethoxypyrimidin-2-
yl)thio]benzoate), in or on cotton, undelinted seed at 0.02 parts per 
million (ppm) and cotton gin byproducts at 0.1 ppm. The Registrant 
subsequently amended the petition by

[[Page 72105]]

increasing the tolerance request for cotton gin byproducts to 0.15 ppm.
    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 
children from aggregate exposure to the pesticide chemical residue. . . 
.''
    EPA performs a number of analyses to determine the risks from 
aggregate exposure to pesticide residues. For further discussion of the 
regulatory requirements of section 408 and a complete description of 
the risk assessment process, see the final rule on Bifenthrin Pesticide 
Tolerances November 26, 1997, (62 FR 62961) (FRL-5754-7).

III. Aggregate Risk Assessment and Determination of Safety

    Consistent with section 408(b)(2)(D), EPA has reviewed the 
available scientific data and other relevant information in support of 
this action. EPA has sufficient data to assess the hazards of and to 
make a determination on aggregate exposure, consistent with section 
408(b)(2), for a tolerance for residues of pyrithiobac sodium on 
cotton, undelinted seed at 0.02 ppm and cotton gin byproducts at 0.15 
ppm. EPA's assessment of exposures and risks associated with 
establishing the tolerance follows.

A. Toxicological Profile

    EPA has evaluated the available toxicity data and considered its 
validity, completeness, and reliability as well as the relationship of 
the results of the studies to human risk. EPA has also considered 
available information concerning the variability of the sensitivities 
of major identifiable subgroups of consumers, including infants and 
children. The nature of the toxic effects caused by pyrithiobac sodium 
are discussed below. This discussion refers to the no observed effect 
level (NOEL) and the lowest observed effect level (LOEL) from the 
toxicity studies reviewed rather than the no observed adverse effect 
level (NOAEL) and the lowest observed adverse effect level (LOAEL) 
because the toxicity studies for pyrithiobac sodium were reviewed prior 
to adoption in 1998 of the NOAEL/LOAEL terminology by EPA's Office of 
Pesticide Programs (OPP) and its Health Effects Division (HED). At the 
time of the switch to the revised terminology, HED noted that the new 
terminology was unlikely to have any substantive effect on its hazard 
evaluations: ``In a practical sense, the terms NOEL and NOAEL have been 
used interchangeably in OPP. As a general rule, OPP would consider as 
appropriate for hazard identification and risk assessment only those 
effects which are adverse or potentially adverse. This inclusion of the 
term NOAEL should not change any of our hazard endpoints for regulation 
but add to the quality of the risk assessment.'' HED Standard Operating 
Procedure (SOP) 98.3
    1. A rat acute oral study with a LD50 of 3,300 
milligrams/kilogram (mg/kg) for males and a LD50 of 3,200 
mg/kg for females.
    2. A 90-day rat feeding study with a NOAEL of 50 parts per million 
(ppm) (3.25 mg/kg/day for males and 4.14 mg/kg/day for females) and a 
LOAEL of 500 ppm (31.8 mg/kg/day for males and 40.5 mg/kg/day for 
females based on decrease body weight gains and increased rate of 
hepatic beta-oxidation in males.
    3. A 90-day mouse feeding study with a NOAEL of 500 ppm (83.1 mg/
kg/day for males and 112 mg/kg/day for females) and a LOAEL of 1,500 
ppm (263 mg/kg/day for males and 384 mg/kg/day for females) based on 
increased liver weight and an increased incidence of hepatocellular 
hypertrophy in males and decreased neutrophil count in females.
    4. A 3-month dog feeding study with a NOAEL of 5,000 ppm (165 mg/
kg/day) and a LOAEL of 20,000 ppm (626 mg/kg/day), based on decrease 
red blood cell count, hemoglobin, and hematocrit in females and 
increased liver weight in both sexes.
    5. A 21-day rat dermal study with a Dermal Irritation NOAEL of 50 
mg/kg/day and, a Dermal Irritation LOAEL of 500 mg/kg/day based on 
increased incidence of erythema and edema, and with a Systemic Dermal 
NOAEL of 500 mg/kg/day and a Systemic Dermal LOAEL of 1,200 mg/kg/day 
based on body weight gain inhibition.
    6. A 90-day rat neurotoxicity screening battery with a Systemic 
NOAEL of 7,000 ppm (466 mg/kg/day for males and 588 mg/kg/day for 
females) and a Systemic LOAEL of 20,000 ppm (1,376 mg/kg/day for males 
and 1,609 mg/kg/day for females), based on deceased hind grip strength 
and increased foot spay in males, and a Neurotoxicity NOAEL of 20,000 
ppm highest dose tested (HDT).
    7. A 78-week dietary carcinogenicity study in mice with a NOAEL of 
1,500 ppm 217 mg/kg/day (males) and 319 mg/kg/day (females) and a LOAEL 
of 5,000 ppm 745 mg/kg/day (males) and 1,101 mg/kg/day (females) based 
on decreased body weight gain in both sexes, treatment related increase 
in the incidence of foci/focus of hepatocellular alternation in males, 
and increased incidence of glomerulonephropathy (murine) in both sexes, 
and an increased incidence of infarct in the kidney and keratopathy of 
the eyes. There was evidence of carcinogenicity based on significant 
differences in the pair-wise comparisons of hepatocellular adenomas and 
combined adenoma/carcinoma in the 150 ppm and 1,500 ppm dose groups 
(but not at the high dose of 5,000 ppm) with the controls. The 
carcinogenic effects observed are discussed below.
    8. A 23-month rat chronic toxicity/carcinogenicity study with a 
Systemic NOAEL of 1,500 ppm (58.7 mg/kg/day) for males and 5,000 ppm 
(278 mg/kg/day) for females, and with a Systemic LOAEL of 5,000 ppm 
(200 mg/kg/day) for males and 15,000 ppm (918 mg/kg/day) for females, 
based on deceased body weight, body weight gain and food efficiency for 
females, the increased incidence of eye lesions in both sexes, mild 
changes in hematology and urinalysis in both sexes, clinical signs 
suggestive of urinary tract dysfunction in males and females, increased 
incidence of focal cystic degeneration in the liver in males, increased 
rate of hepatic peroxisomal beta-oxidation in males and an increased 
incidence of inflammatory and degenerative lesions in the kidney in 
females. There was evidence of carcinogenicity based on significant 
dose-related increasing trend in kidney tubular combined adenoma/
carcinoma in male rats and a significant dose related increasing trend 
in kidney tubular bilateral and/or unilateral adenomas in females. The 
carcinogenic effects observed are discussed further below.
    9. A 1-year dog chronic toxicity study with a NOAEL of 5,000 ppm 
(143 mg/kg/day for males and 166 mg/kg/day for females) and a LOAEL of 
20,000 ppm (580 mg/kg/day for males and 647 mg/kg/day for females) 
based on decreases in body weight gain, increase thyroid

[[Page 72106]]

and liver weights, and microscopic findings in the liver and kidneys.
    10. A 2-generation reproduction study in rats with a NOAEL for 
maternal toxicity of 1,500 ppm (103 mg/kg/day) and a maternal LOAEL of 
7,500 ppm (508 mg/kg/day), based on decreased body weight, body weight 
gain and food efficiency. The NOAEL for paternal toxicity is 1,500 ppm 
(86 mg/kg/day), while the LOAEL is 7,500 ppm (439 mg/kg/day), based on 
decreased body weight, body weight gain and food efficiency. The NOAEL 
for reproductive effects can be set at 7,500 ppm (508 mg/kg/day), the 
LOAEL at 20,000 ppm (1,551 mg/kg/day), based on decreased pup body 
weight. The NOAEL for effects on offspring is 7,500 ppm (508 mg/kg/
day), and the LOAEL at 20,000 ppm (1,551 mg/kg/day), based on decreased 
pup body weight.
    11. A 13-day dosing (gestation days 7-19) developmental toxicity 
study in rabbits with a maternal NOAEL of 300 mg/kg and a maternal 
LOAEL of 1,000 mg/kg based on deaths, decreased body weight gain and 
feed consumption, and an increase in early resorptions. There is 
developmental toxicity observed at 1,000 mg/kg based on decreased fetal 
body weights.
    12. A 10-day dosing (gestation days 7-16) developmental toxicity 
study in rats wth a maternal NOAEL of 200 mg/kg and maternal LOAEL of 
600 mg/kg due to increased incidence of peritoneal staining. The 
developmental NOAEL is 600 mg/kg and the developmental LOAEL is 1,800 
mg/kg based on the increased incidence of skeletal variations.
    13. No evidence of gene mutation was observed in a test for 
induction of forward mutations at the hypoxanthine guanine 
phophoribosyl transferase (HGPRT) locus in Chinese hamster ovary cells. 
No evidence was observed for inducing reverse gene mutation in two 
independent assays with Salmonella typhimurium with and without 
mammalian metabolic activation. Pyrithiobac sodium was negative for the 
induction of micronuclei in the bone marrow cells of mice, and negative 
for induction of unscheduled DNA synthesis in rat primary hepatocytes. 
Pyrithiobac sodium was positive for inducing chromosome aberrations 
assay in human lymphocytes.
    14. A rat metabolism study showed that radio labeled pyrithiobac 
sodium is excreted in urine and feces with >90% being eliminated within 
48 hours. A sex difference was observed in the excretion and 
biotransformation. Females excreted a greater amount of the radiolabel 
in the urine than males following all regimens, with a corresponding 
lower amount being eliminated in the feces compared to the males.

B. Toxicological Endpoints

    The dose at which the NOAEL from the toxicology study identified as 
appropriate for use in risk assessment is used to estimate the 
toxicological level of concern (LOC). However, the LOAEL at which 
effects of concern are identified 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 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.
    For non-dietary risk assessments (other than cancer) the UF is used 
to determine the 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) = NOEL/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 x 106 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 pyrithiobac sodium used for human risk assessment is as 
follows:
    1. Acute toxicity. EPA has concluded that no endpoint exists to 
suggest any evidence of significant toxicity from 1-day or single-event 
exposure.
    2. Short-term and intermediate-term toxicity. EPA has concluded 
that available evidence does not indicate any evidence of significant 
toxicity from short-term and intermediate-term exposure.
    3. Chronic toxicity. EPA has established the RfD for pyrithiobac 
sodium at 0.587 mg/kg/day. This RfD is based on the systemic NOAEL of 
58.7 mg/kg/day for males in the rat chronic feeding study with a 100-
fold safety factor to account for interspecies extrapolation and 
intraspecies variability.
    4. Carcinogenicity. EPA has concluded that the available data 
provide limited evidence of the carcinogenicity of pyrithiobac sodium 
in mice and rats and has classified pyrithiobac sodium as a Group C 
(possible human carcinogen with limited evidence of carcinogenicity in 
animals) in accordance with Agency guidelines, published in the Federal 
Register of (September 24, 1986, 51 FR 33992) and recommended that for 
the purpose of risk characterization a low dose extrapolation model 
should be applied to the experimental animal tumor data for 
quantification for human risk (Q1*). This decision was based 
on liver adenomas, carcinomas and combined adenoma/carcinomas in the 
male mouse and rare kidney tubular adenomas, carcinomas and combined 
adenoma/carcinomas in male rats. The unit risk, Q1* (mg/kg/
day)-1, of pyrithiobac sodium is 1.05 x 10-3 (mg/kg/day)-1 in human 
equivalents based on male kidney tumors.

C. Exposure Assessment

    1. Dietary exposure from food and feed uses. Permanent tolerances 
have been requested to replace the time limited tolerance in/on 
cottonseed 40 CFR 180.487 at 0.02 ppm, and a new tolerance for the 
residues of pyrithiobac sodium, in or on cotton gin byproducts at 0.1 
ppm. The requested tolerance for cotton gin byproducts has been amended 
to 0.15 ppm based on the results of the submitted field residue trials, 
and cottonseed was changed to cotton, undelinted seed. Processing 
studies for cotton have shown that

[[Page 72107]]

pyrithiobac sodium does not concentrate in cottonseed processed food/
feed commodities. No requested tolerances were necessary for meat, 
milk, and eggs because detectible residues are not expected in these 
commodities from this use on cotton. Risk assessments were conducted by 
EPA to assess dietary exposures from pyrithiobac sodium 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 1-day or 
single exposure. EPA has concluded that no endpoint exists to suggest 
any evidence of significant toxicity from one-day or single-event 
exposure; therefore, an acute exposure assessment is not applicable.
    ii. Chronic exposure. In conducting this chronic dietary risk 
assessment the Dietary Exposure Evaluation Model (DEEMTM 
analysis evaluated the individual food consumption as reported by 
respondents in the Department of Argiculture (USDA) 1989-1992 
nationwide Continuing Surveys of Food Intake by Individuals (CSFII) and 
accumulated exposure to the chemical for each commodity. EPA assumed 
that all commodities for which tolerances exist and all cotton food 
commodities had pyrithiobac sodium residues at the appropriate 
tolerance level.
    iii. Cancer. The cancer exposure assessment relied upon the same 
data and assumptions as the chronic exposure assessment.
    iv. Anticipated residue and percent crop treated (PCT) information. 
Tolerance level residues and treatment of 100% of the crop was assumed. 
Anticipated residues and PCT information was not used.
    2. Dietary exposure from drinking water. The Agency lacks 
sufficient monitoring exposure data to complete a comprehensive dietary 
exposure analysis and risk assessment for pyrithiobac sodium 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 pyrithiobac sodium.
    The Agency uses the GENEEC or the PRZM/EXAMS to estimate pesticide 
concentrations in surface water and 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 (PC) area 
factor as an adjustment to account for the maximum PC 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 
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 pyrithiobac sodium they are 
further discussed in the aggregate risk sections in Unit E.
    Based on the GENEEC and SCI-GROW models the EECs of pyrithiobac 
sodium for chronic exposures are estimated to be 7.76 parts per billion 
(ppb) for surface water and 0.778 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).
    Pyrithiobac sodium is not registered for use on any sites that 
would result in residential exposure.
    4. Cumulative exposure to substances with a common mechanism of 
toxicity. Section 408(b)(2)(D)(v) requires that, when considering 
whether to establish, modify, or revoke a tolerance, the Agency 
consider ``available information'' concerning the cumulative effects of 
a particular pesticide's residues and ``other substances that have a 
common mechanism of toxicity.''
    EPA does not have, at this time, available data to determine 
whether pyrithiobac sodium has a common mechanism of toxicity with 
other substances or how to include this pesticide in a cumulative risk 
assessment. Unlike other pesticides for which EPA has followed a 
cumulative risk approach based on a common mechanism of toxicity, 
pyrithiobac sodium 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 pyrithiobac sodium has a 
common mechanism of toxicity with other substances. For information 
regarding EPA's efforts to determine which chemicals have a common 
mechanism of toxicity and to evaluate the cumulative effects of such 
chemicals, see the final rule for Bifenthrin Pesticide Tolerances 
(November 26, 1997, 62 FR 62961).

D. Safety Factor for Infants and Children

    1. In general. FFDCA section 408 provides that EPA shall apply an 
additional tenfold margin of safety for infants and children in the 
case of threshold effects to account for pre-natal and post-natal 
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. Pre-natal and post-natal sensitivity. In a preliminary review, 
EPA concluded that data do not indicate that there is a significant 
potential for reproductive or developmental effects from pyrithiobac 
sodium as tested.
    3. Conclusion. There is a complete toxicity data base for 
pyrithiobac sodium and exposure data are complete or are estimated 
based on data that reasonably accounts for potential exposures. 
Pyrithiobac sodium has not been formally reviewed by the Agency 
regarding the need to retain the additional 10X safety factor for the 
protection of infants and children. Thus, despite the completeness of 
the database and the lack of any indication of significant potential 
for reproductive or developmental effects, EPA has retained the 
additional 10X safety factor until a full review can be completed. 
Retention of the additional safety factor yields a

[[Page 72108]]

cPAD for pyrithiobac sodium of 0.0587 mg/kg/day.

E. 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 + 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 EPA Office of Water are used to calculate DWLOCs: 2L/
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 the pesticide 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 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. If new 
uses are added in the future, EPA will reassess the potential impacts 
of residues of the pesticide in drinking water as a part of the 
aggregate risk assessment process.
    Pyrithiobac sodium is not registered for use on any sites that 
would result in residential exposure. Therefore, the aggregate risk is 
the sum of the risk from food and water.
    1. Acute risk. EPA has concluded that no endpoint exists to suggest 
any evidence of significant toxicity from acute exposures from the use 
of pyrithiobac sodium on cotton.
    2. Chronic risk. Using the exposure assumptions described in this 
unit for chronic exposure, EPA has concluded that exposure to 
pyrithiobac sodium from food and water will utilize less than 0.2% of 
the cPAD for the U.S. population, and less than 0.2% of the cPAD for 
children 1 to 6 years at greatest exposure to both food and water. 
There are no residential uses for pyrithiobac sodium that result in 
chronic residential exposure to pyrithiobac sodium. EPA generally has 
no concern for exposures below 100% of the cPAD because the cPAD 
represents the level at or below which aggregate dietary exposure over 
a lifetime will not pose appreciable risks to human health. Due to the 
low exposure for the U.S. population (less than 0.2%) and for children 
1 to 6 years (less than 0.2%) for both food and water, the calculated 
DWLOC is approximately equal to the cPAD.
    3. Short-term risk. EPA has concluded that no endpoint exists to 
suggest any evidence of significant toxicity from short-term exposures 
from the use of pyrithiobac sodium on cotton.
    4. Intermediate-term risk. EPA has concluded that no endpoint 
exists to suggest any evidence of significant toxicity from 
intermediate-term exposures from the use of pyrithiobac sodium on 
cotton.
    5. Aggregate cancer risk for U.S. population. Based on the upper 
bound potency factor (Q*1) of 1.05 x 10-3 (mg/kg/day)-1, the aggregate 
upper bound lifetime cancer risk from the use of pyrithiobac sodium on 
cotton from worst case estimates of residues in food and drinking water 
is 2.3 x 10-7.
    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 pyrithiobac sodium residues.

IV. Other Considerations

A. Analytical Enforcement Methodology

    Adequate enforcement methodology high performance liquid 
chromotography using ultra-violent detection (HPLC-UV) with column 
switching) is available to enforce the tolerance expression. The method 
may be requested from: Paul Golden, U.S. Environmental Protection 
Agency, Office of Pesticide Programs, BEAD, ACB, Environmental Science 
Center, 701 Mapes Road Fort Meade, MD 20755-5350; Telephone (410) 305-
2960.

B. International Residue Limits

    There are no established Codex maximum residue levels (MRLs) for 
pyrithiobac sodium on cottonseed. An established Mexican tolerance for 
pyrithiobac sodium on cottonseed is identical to the U.S. tolerance. 
Compatibility of tolerance levels is not an issue at this time.

C. Conditions

    There are no conditions. Adequate residue data has been submitted 
to support the tolerances established in this Federal Register Notice.

V. Conclusion

    Therefore, the tolerance is established for residues of pyrithiobac 
sodium, (sodium 2-chloro-6-[(4,6-dimethoxypyrimidin-2-
yl)thio]benzoate), in or on cotton, undelinted seed at 0.02 ppm and 
cotton gin byproducts at 0.15 ppm.

VI. 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 of 1996, EPA will continue to use those 
procedures, with appropriate adjustments, until the necessary 
modifications can be made. The new section 408(g) 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), as was provided in the old FFDCA sections 408 and 409. 
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-2002-0005 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 February 
3, 2003.

[[Page 72109]]

    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 (1900), 
Environmental Protection Agency, 1200 Pennsylvania Ave., NW., 
Washington, DC 20460. You may also deliver your request to the Office 
of the Hearing Clerk in Rm. C400, Waterside Mall, 401 M St., SW., 
Washington, DC 20460. 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) 260-4865.
    2. Tolerance fee payment. If you file an objection or request a 
hearing, you must also pay the fee prescribed by 40 CFR 180.33(i) or 
request a waiver of that fee pursuant to 40 CFR 180.33(m). You must 
mail the fee to: EPA Headquarters Accounting Operations Branch, Office 
of Pesticide Programs, P.O. Box 360277M, Pittsburgh, PA 15251. Please 
identify the fee submission by labeling it ``Tolerance Petition Fees.''
    EPA is authorized to waive any fee requirement ``when in the 
judgement of the Administrator such a waiver or refund is equitable and 
not contrary to the purpose of this subsection.'' For additional 
information regarding the waiver of these fees, you may contact James 
Tompkins by phone at (703) 305-5697, by e-mail at [email protected], 
or by mailing a request for information to Mr. Tompkins at Registration 
Division (7505C), Office of Pesticide Programs, Environmental 
Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460.
    If you would like to request a waiver of the tolerance objection 
fees, you must mail your request for such a waiver to: James Hollins, 
Information Resources and Services Division (7502C), Office of 
Pesticide Programs, Environmental Protection Agency, 1200 Pennsylvania 
Ave., NW., Washington, DC 20460.
    3. Copies for the Docket. In addition to filing an objection or 
hearing request with the Hearing Clerk as described in Unit VI.A., you 
should also send a copy of your request to the PIRIB for its inclusion 
in the official record that is described in Unit I.B.2. Mail your 
copies, identified by docket ID number OPP-2002-0005, 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. 
In person or by courier, bring a copy to the location of the PIRIB 
described in Unit I.B.2. You may also send an electronic copy of your 
request via e-mail to: [email protected]. 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 issues(s) in the manner sought 
by the requestor would be adequate to justify the action requested (40 
CFR 178.32).

VII. Regulatory Assessment Requirements

    This final rule establishes a tolerance under FFDCA section 408(d) 
in response to a petition submitted to the Agency. The Office of 
Management and Budget (OMB) has exempted these types of actions from 
review under Executive Order 12866, entitledRegulatory 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 
petition under FFDCA section 408(d), such as the tolerance in this 
final rule, do not require the issuance of a proposed rule, the 
requirements of the Regulatory Flexibility Act (RFA) (5 U.S.C. 601 et 
seq.) do not apply. 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 FFDCA section 408(n)(4). For these same reasons, the Agency has 
determined that this rule does not have

[[Page 72110]]

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 andIndian 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.

VIII. Submission to Congress and the Comptroller General

    The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the 
Small Business Regulatory Enforcement Fairness Act of 1996, generally 
provides that before a rule may take effect, the agency promulgating 
the rule must submit a rule report, which includes a copy of the rule, 
to each House of the Congress and 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 8, 2002.
Debra Edwards,
Acting Director, Registration Division, Office of Pesticide Programs.

    Therefore, 40 CFR chapter I is amended as follows:

PART 180--[AMENDED]

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

    Authority: 21 U.S.C. 321(q), 346(a) and 374.

    2. Section 180.487 paragraph (a) is revised to read as follows:


Sec.  180.487  Pyrithiobac sodium; tolerances for residues.

    (a) General. Tolerances are established for residues of the 
herbicide, pyrithiobac sodium, (sodium 2-chloro-6-[(4,6-
dimethoxypyrimidin-2-yl)thio]benzoate), resulting from the application 
of the pesticide chemical in or on the following foods/feeds:

----------------------------------------------------------------------------------------------------------------
                       Commodity                                            Parts per million
----------------------------------------------------------------------------------------------------------------
Cotton gin byproducts.................................                                                      0.15
Cotton, undelinted seed...............................                                                      0.02
----------------------------------------------------------------------------------------------------------------

* * * * *
[FR Doc. 02-30472 Filed 12-3-02; 8:45 am]
BILLING CODE 6560-50-S