Document ID: EPA-HQ-OPP-2005-0056-0001
Agency: epa
Document Type: Rule
Title: Pendimethalin; Pesticide Tolerance
Posted Date: 2006-04-12T13:58:38Z

[Federal Register: April 12, 2006 (Volume 71, Number 70)]
[Rules and Regulations]               
[Page 18628-18635]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr12ap06-9]                         

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[EPA-HQ-OPP-2005-0056; FRL-7770-4]

 
Pendimethalin; Pesticide Tolerance

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This regulation establishes a tolerance for combined residues 
of pendimethalin, [N-(1-ethylpropyl)-3,4-dimethyl-2,6-
dinitrobenzenamine], and its metabolite 4-[(1-ethylpropyl)amino]-2-
methyl-3,5-dinitrobenyzl alcohol in or on carrots; spearmint, tops; 
peppermint, tops; spearmint, oil; peppermint, oil; fruit, citrus, group 
10, citrus, oil; almond, hulls; nut, tree group 14. Interregional 
Research Project Number 4 requested this tolerance under the Federal 
Food, Drug, and Cosmetic Act (FFDCA), as amended by the Food Quality 
Protection Act of 1996 (FQPA).

DATES: This regulation is effective April 12, 2006. Objections and 
requests for hearings must be received on or before June 12, 2006.

ADDRESSES: To submit a written objection or hearing request follow the 
detailed instructions as provided in Unit VI. of the SUPPLEMENTARY 
INFORMATION. EPA has established a docket for this action under Docket 
identification (ID) number EPA-HQ-OPP-2005-0056. All documents in the 
docket are listed on the http://www.regulations.gov web site, (EDOCKET, EPA's 

electronic public docket and comment system was replaced on November 
25, 2005, by an enchanced Federal-wide electronic docket management and 
comment system located at http://www.regulations.gov/. Follow the on-

line instructions. 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: Jim Tompkins, Registration Division 
(7505C), Office of Pesticide Programs, Environmental Protection Agency, 
1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone 
number: (703) 305-5805; e-mail address: tompkins.jim@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 111), e.g., agricultural workers; 
greenhouse, nursery, and floriculture workers; farmers.
     Animal production (NAICS 112), e.g., cattle ranchers and 
farmers, dairy cattle farmers, livestock farmers.
     Food manufacturing (NAICS 311), e.g., agricultural 
workers; farmers; greenhouse, nursery, and floriculture workers; 
ranchers; pesticide applicators.
     Pesticide manufacturing (NAICS 32532), e.g., agricultural 
workers; commercial applicators; farmers; greenhouse, nursery, and 
floriculture workers; residential users.
    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/.Follow
 the on-line instructions. A frequently updated 

electronic version of 40 CFR part 180 is available at E-CFR Beta Site 
Two athttp://www.epa.gpoaccess.gov/ecfr/.

II. Background and Statutory Findings

    In the Federal Register of September 1, 1999 (64 FR 47797) (FRL-
6096-8), and March 19, 2001, (66 FR 15464) (FRL-6766-8), EPA issued a 
notice pursuant to section 408(d)(3) of FFDCA, 21 U.S.C. 346a(d)(3), 
announcing the filing of pesticide petitions PP 6E4603, PP 6E4787, PP 
7E4878, and 0E6083 by Interregional Research Project Number 4 (IR-4), 
681 U.S. Highway 1 South, North Brunswick, NJ 08902-390. The 
petitions requested that 40 CFR part 180 be amended by establishing a 
tolerance for combined residues of the herbicide pendimethalin, N-(1-
ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzenamine, and its metabolite 4-
[(1-ethylpropyl)amino]-2-methyl-3,5-dinitrobenyzl alcohol, in or on 
carrots at 0.5 parts per million (ppm); (6E4603); peppermint and 
spearmint tops at 0.2 ppm; (7E4878); peppermint and spearmint oil at 
1.0 ppm (7E4878); fruit, citrus, group 10 at 0.1 ppm (6E4787); citrus, 
oil at 0.5 ppm, (6E4787); almond, hulls at 0.4 ppm; (0E6083); and nut, 
tree group 14 at 0.1 ppm (0E6083). That notice included a summary of 
the petition prepared by IR-4, the registrant. There were no comments 
received in response to the notice of filing.
    Section 408(b)(2)(A)(i) of FFDCA allows EPA to establish a 
tolerance (the legal limit for a pesticide chemical residue in or on a 
food) only if EPA determines that the tolerance is ``safe.'' Section 
408(b)(2)(A)(ii) of FFDCA defines ``safe'' to mean that ``there is a 
reasonable certainty that no harm will result from aggregate exposure 
to the pesticide chemical residue, including all anticipated dietary 
exposures and all other exposures for which there is reliable 
information.'' This includes

[[Page 18629]]

exposure through drinking water and in residential settings, but does 
not include occupational exposure. Section 408(b)(2)(C) of FFDCA 
requires EPA to give special consideration to exposure of infants and 
children to the pesticide chemical residue in establishing a tolerance 
and to ``ensure that there is a reasonable certainty that no harm will 
result to infants and children from aggregate exposure to the pesticide 
chemical residue. . . . ''
    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 http://www.epa.gov/fedrgstr/EPA-PEST/1997/November/Day-26/p30948.htm
.

III. Aggregate Risk Assessment and Determination of Safety

    Consistent with section 408(b)(2)(D) of FFDCA, EPA has reviewed the 
available scientific data and other relevant information in support of 
this action. EPA has sufficient data to assess the hazards of and to 
make a determination on aggregate exposure, consistent with section 
408(b)(2) of FFDCA, for a tolerance for pendimethalin and its 
metabolite in or on carrots at 0.5 ppm; peppermint and spearmint tops 
at 0.2 ppm; peppermint and speamint oil at 1.0 ppm; fruit, citrus, 
group 10 at 0.1 ppm; citrus, oil at 0.5 ppm; almond, hulls at 0.4 ppm; 
and nuts, tree group 14 at 0.1 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. Specific information on the studies received and the nature 
of the toxic effects caused by pendimethalin and its metabolite as well 
as the no-observed-adverse-effect-level (NOAEL) and the lowest-
observed-adverse-effect-level (LOAEL) from the toxicity studies can be 
found at http://www.fdms.gov.

B. Toxicological Endpoints

    For hazards that have a threshold below which there is no 
appreciable risk, 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 
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.
    Three other types of safety or UFs may be used: ``Traditional 
UFs;'' the ``FQPA data safety factor;'' and the ``default FQPA safety 
factor.'' By the term ``traditional UFs,'' EPA is referring to those 
additional UFs used prior to FQPA passage to account for database 
deficiencies. These traditional UFs have been incorporated by the FQPA 
into the additional safety factor for the protection of infants and 
children. The term ``FQPA data safety factor'' refers to those safety 
factors that are deemed necessary for the protection of infants and 
children primarily as a result of the FQPA. The ``default FQPA safety 
factor'' is the additional 10X safety factor that is mandated by the 
statute unless it is decided that there are reliable data to choose a 
different additional factor (potentially a traditional UF or a FQPA 
data safety factor).
    For dietary risk assessment (other than cancer) the Agency uses the 
UF to calculate an acute or chronic reference dose (aRfD or cRfD) where 
the RfD is equal to the NOAEL divided by an UF of 100 to account for 
interspecies and intraspecies differences and any traditional UFs 
deemed appropriate (RfD = NOAEL/UF). Where a FQPA data safety factor or 
the default FQPA safety factor is used, 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 safety factor.
    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 
(e.g., risk). An example of how such a probability risk is expressed 
would be to describe the risk as one in one hundred thousand (1 X 
10-5), one in a million (1 X 10-6), or one in ten 
million (1 X 10-7). 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.
    The data base for pendimethalin does not indicate a potential for 
increased toxicological sensitivity from either prenatal or postnatal 
exposures. In the submitted rat and rabbit developmental studies, no 
adverse effects were observed at doses tested. These studies were 
considered adequate, and no additional developmental toxicity studies 
are required. There was no evidence of qualitative or quantitative 
susceptibility in a 2-generation reproduction study conducted in the 
rat. There was no neurotoxicity observed in the submitted studies, and 
no evidence of qualitative or quantitative susceptibility in the 
developmental and reproduction studies; therefore, a developmental 
neurototoxicity study has not been required, and the 10X Special FQPA 
factor has been reduced to 1X.
    Hormonal changes (alterations in thyroid weights and 
histopathological lesions) were observed in several studies following 
oral administration of pendimethalin and it is likely that these 
changes may cause disruption in the endocrine system. There is concern 
that perturbation of thyroid homeostasis may lead to hypothyroidism, 
and possibly result in adverse effects on the developing nervous 
system. Consequently, the Agency has required that a developmental 
thyroid assay be conducted to evaluate the impact of pendimethalin on 
thyroid hormones, structure, and/or thyroid hormone homeostasis during 
development. Pending receipt of the study, the Agency has retained a 
10X data base UF to provide adequate protection of infants and children 
from potential thyroid effects.

[[Page 18630]]

    The standard 10X intraspecies uncertainty factor and a 3X 
interspecies factor are applicable to pendimethalin risk assessments. 
The interspecies uncertainty factor of 10X was reduced to 3X due to the 
greater sensitivity of the adult rat to thyroid effects compared to the 
adult humans. Because of toxicodynamic differences in adult thyroid 
function that result in greater sensitivity of the adult rat to 
hypothyroidism compared to adult humans, the 3X toxicodynamic part of 
the 10X can be removed leaving the 3X portion for toxicokinetic 
interspecies differences based on the Agency's Interim Guidance on 
Thyroid Disrupting Pesticides, dated November 1, 2005. Thus, the usual 
100X UF for intraspecies and interspecies differences is reduced to 
30X. A data base UF of 10X was retained for residential exposures 
pending receipt of the developmental thyroid study. The level of 
concern (target MOE) for residential exposure is 300X.
    A summary of the toxicological endpoints for pendimethalin used for 
human risk assessment is shown in the following Table 1:

           Table 1.--Toxicological Doses and Endpoints for Pendimethalin Human Health Risk Assessments
----------------------------------------------------------------------------------------------------------------
                                                                FQPA data SF* and Level
          Exposure Scenario               Dose Used in Risk       of Concern for Risk    Study and Toxicological
                                            Assessment, UF             Assessment                Effects
----------------------------------------------------------------------------------------------------------------
                                                Dietary exposure
----------------------------------------------------------------------------------------------------------------
Acute dietary (females 13-49)          NA                       NA                       No appropriate acute
General US pop.).....................                                                     endpoint identified
                                                                                          for these groups.
                                                                                          There were no toxic
                                                                                          effects attributable
                                                                                          to a single dose
----------------------------------------------------------------------------------------------------------------
Chronic dietary (all populations)      NOAEL = 10 mg/kg/day     FQPA SF = 1X             92-day thyroid function
                                       UF = 10X (intraspecies)  cPAD = Chronic RfD FQPA   study in rats; 56-day
                                       UF = 3X (interspecies).   SF.                      thyroid study in rats;
                                       UF = 10X (data base)...  cPAD = 0.03 mg/kg/day..   14-day intra thyroid
                                       Total UF = 300X........                            metabolism study in
                                       Chronic RfD= 0.03 mg/kg/                           rats
                                        day.                                             LOAEL= 31 mg/kg/day
                                                                                          based on hormonal and
                                                                                          histopathological
                                                                                          changes in the thyroid
----------------------------------------------------------------------------------------------------------------
                                                 Oral ingestion
----------------------------------------------------------------------------------------------------------------
Incidental oral short-term (1-30       NOAEL = 10 mg/kg/day     FQPA SF = 1X             92-day thyroid function
 days)                                 UF = 10X (intraspecies)  Residential LOC = 300..   study in rats; 56-ay
Intermediate-term (1-6 months).......  UF = 3X (interspecies).                            thyroid study in rats;
                                       UF = 10X (data base)...                            14-ay intra thyroid
                                       Total UF = 300X........                            metabolism study in
                                                                                          rats
                                                                                         LOAEL= 31 mg/kg/day
                                                                                          based on hormonal and
                                                                                          histopathological
                                                                                          changes in the thyroid
----------------------------------------------------------------------------------------------------------------
                                                 Dermal exposure
----------------------------------------------------------------------------------------------------------------
Dermal short-term (1-30 days)          NOAEL = 10 mg/kg/day     FQPA SF = 10X            92-day thyroid function
Intermediate-term (1-6 months).......  UF = 10X (intraspecies)  Residential LOC = 300..   study in rats; 56-day
Long-term (>6 months)................  UF = 3X (interspecies).  Occupational LOC = 30..   thyroid study in rats;
                                       UF = 10X (data base)...                            14-day intra thyroid
                                       Total UF = 300X........                            metabolism study in
                                       Dermal absorption = 3%.                            rats
                                                                                         LOAEL= 31 mg/kg/day
                                                                                          based on hormonal and
                                                                                          histopathological
                                                                                          changes in the thyroid
----------------------------------------------------------------------------------------------------------------
                                               Inhalation exposure
----------------------------------------------------------------------------------------------------------------
Inhalation short-term (1-30 days)      NOAEL = 10 mg/kg/day     FQPA SF = 1X             92-day thyroid function
Intermediate-term (1-6 months).......  UF = 10X (intraspecies)  Residential LOC = 300..   study in rats; 56-day
Long-term (>6 months)................  UF = 3X (interspecies).                            thyroid study in rats;
                                       UF = 10X (data base)...                            14-day intra thyroid
                                       Total UF = 300X........                            metabolism study in
                                       Inhalation absorption =                            rats
                                        100%.                                            LOAEL= 31 mg/kg/day
                                                                                          based on hormonal and
                                                                                          histopathological
                                                                                          changes in the thyroid
                                                                                         .......................
----------------------------------------------------------------------------------------------------------------
                                                     Cancer
----------------------------------------------------------------------------------------------------------------
Cancer (oral, dermal, inhalation)      Pendimethalin is         2-year chronic/
                                        considered to be a       carcinogenicity study
                                        possible human           in rats
                                        carcinogen. The linear
                                        default risk
                                        methodology was not
                                        appropriate and non-
                                        linear, RfD approach
                                        was used
----------------------------------------------------------------------------------------------------------------
 UF = uncertainty factor, FQPA SF = FQPA data safety factor, NOAEL = no observed adverse effect level, LOAEL =
  lowest observed adverse effect level, PAD = population adjusted dose (a = acute, c = chronic) RfD = reference
  dose, MOE = margin of exposure, LOC = level of concern, NA = Not Applicable* Refer to discussion above

[[Page 18631]]

    Pendimethalin is classified as a ``Group C'', possible human 
carcinogen, chemical based on a statistically significant increased 
trend and pair-wise comparison between the high dose group and controls 
for thyroid follicular cell adenomas in male and female rats. A non-
quantitative approach (i.e., non-linear, RfD approach) was used by the 
Agency since mode of action studies are available that demonstrate that 
the thyroid tumors are due to a thyroid-pituitary imbalance, and also 
since pendimethalin was shown to be non-mutagenic in mammalian somatic 
cells and germ cells. The cPAD from the 92-day thyroid function study 
in rats; 56-day thyroid study in rats; 14-day intra thyroid metabolism 
study in rats used for the chronic dietary assessment provide adequate 
MOE's for cancer.

C. Exposure Assessment

    1. Dietary exposure from food and feed uses. Tolerances have been 
established (40 CFR 180.361), for the combined residues of 
pendimethalin in or on a variety of raw agricultural commodities. Risk 
assessments were conducted by EPA to assess dietary exposures from 
pendimethalin in food as follows:
    i. Acute exposure. Quantitative acute dietary exposure and 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.
    No such effects were identified in the toxicological studies for 
pendimethalin therefore, a quantitative acute dietary exposure 
assessment is unnecessary.
    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 United State Department of Agriculture Nationwide 
Continuing Surveys of Food Intake by Individuals (CSFII) and 
accumulated exposure to the chemical for each commodity (CSFII, 1994-
1996, and 1998). Tolerance-level residues were assumed for all food 
commodities with current and proposed pendimethalin tolerances, and it 
was assumed that all of the crops included in the analysis were treated 
(i.e., 100% crop treated). These assumptions result in highly 
conservative estimates of dietary exposure and risk.
    iii. Cancer. Pendimethalin is classified ``Group C'', possible 
human carcinogen, chemical based on a statistically significant 
increased trend and pair-wise comparison between the high dose group 
and controls for thyroid follicular cell adenomas in male and female 
rats. The Agency used a non-quantitative approach (i.e., non-linear, 
RfD approach) since mode of action studies are available that 
demonstrate that the thyroid tumors are due to a thyroid-pituitary 
imbalance, and also since pendimethalin was shown to be non-mutagenic 
in mammalian somatic cells and germ.
    2. Dietary exposure from drinking water. Pendimethalin dissipates 
in the environment by binding to soil, metabolizing by microbes, and by 
volatilizing into air. Persistence decreased with increased 
temperature, increased moisture and decreased soil organic carbon. 
Pendimethalin residues in laboratory and field studies are tightly 
bound to soil and sediment particles, which is consistent with the 
laboratory mobility studies.
    The Agency estimated concentrations in drinking water using Tier II 
screening level surface water modeling (PRZM-EXAMS) for surface water 
and Tier I modeling screening concenteration for ground water (SCI-
GROW2). These Estimated Drinking Water Concentrations 
(EDWCs) may be used for acute, chronic (non-cancer), and chronic 
(cancer) exposure assessments. The PRZM-EXAMS concentrations to be used 
for drinking water ranged from 2.2 to 38.8 micrograms/liter ([mu]/L) 
for peak values, 0.1 to 4.8 [mu]/L for chronic (non-cancer), and 0.1 to 
3.8 [mu]/L for chronic (cancer) exposures.
    The I in 10-year annual peak (acute), 1 in 10-year annual mean 
(non-cancer chronic), and 36-year annual mean concentrations (cancer 
chronic) were derived from modeling pendimethalin on the Pennsylvania 
apple scenario.
    Based on SCI-GROW modeling, the acute and chronic pendimethalin 
concentrations are not expected to exceed 0.024 [mu]/L parts per 
billion (ppb) from one application of 4 lbs active ingredient/A (ai/A). 
The estimated concentrations of up to 0.024 [mu]/L were actually lower 
than the detected concentrations in ground water, ranging from 0.2 to 
0.9 ppb. However, the Agency does not consider pendimethalin to be a 
likely ground water contaminant in most environments based on its 
environmental fate property of tight sorption to soil.
    Parent pendimethalin is the only significant non-volatile residue, 
therefore, the EDWCs were calculated for parent pendimethalin only.
    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).
    Pendimethalin is currently registered for use on the following 
residential non-dietary sites: Landscape, grounds plantings, ornamental 
crops, turf grass, and lawns. Residential handler exposure estimates of 
applying pendimethalin to residential turf were previously assessed in 
the 1996 re-registration eligibility decision document for 
pendimethalin. Since that time registered labels for use of 
pendimethalin on turf have been revised. Turf (ornamental, landscape, 
golf course, non-cropland) in commercial areas can be treated at a rate 
of 3 pounds of ai/A Treatment of turf at residential sites is limited 
to a rate of 2 pounds of ai/A.
    There are two types of potential post-application risks: Dermal and 
incidental oral exposure. Chemical-specific WDG turf transferable 
residue (TTR) data have been submitted to the Agency and reviewed in 
support of assessing dermal exposure to adults and children.
    Ingestion of pendimethalin granules is also a potential source of 
exposure because children can eat them if they are found in treated 
lawns or gardens. This scenario is considered to be episodic, and 
therefore, acute oral endpoints would be used to estimate the risk. A 
risk assessment for this exposure scenario for children was not 
conducted since an acute oral toxicological endpoint of concern was not 
identified for pendimethalin.
    In evaluating the residential uses of pendimethalin, the Agency has 
combined all non-dietary sources of postapplication exposure to obtain 
an estimate of potential aggregate exposure. These scenarios are short-
term in duration and consist of dermal (adults and children) and oral 
(hand-to-mouth, object-to-mouth and soil ingestion - children only) 
exposure. The Agency combines risk values resulting from separate 
exposure scenarios when it is likely they can occur simultaneously 
based on the use-pattern and the behavior associated with the exposed 
population.
    A Tier I aggregate exposure estimate for adults (consisting of 
dermal exposure only) was conducted using the TTR from California test 
site and 3% dermal absorption factor. Since the California test site 
resulted in the lowest dermal margin of exposure (MOE), it was 
determined to represent the worst case scenario. In assessing the 
aggregate residential exposure for children, The Agency also used the 
California TTR data, hand press data and 3% dermal absorption factor 
for determining dermal exposure to children.

[[Page 18632]]

    The LOC for non-occupational dermal exposure is 300. Using the TTR 
data for the Pendulum WDG formulation, children's short-term dermal 
MOEs calculated at a rate of 3.0 lb ai/A ranged from 440 to 910. For 
adults, short-term dermal MOEs ranged from 740 to 1,500. All dermal 
short-term MOEs were greater than 300 and therefore, did not exceed the 
Agency;s LOC.
    All oral (hand-to-mouth, object-to-mouth, and soil ingestion) 
exposures were greater than 300 and therefore, did not exceed the 
Agency's LOC. The MOEs calculated for hand-to-mouth exposures using the 
rate of 2.0 lb ai/A resulted in an MOE of 7,700. The MOEs for object-
to-mouth and soil ingestion exposure were 130,000 and 100,000 
respectively. MOEs calculated for hand-to-mouth exposures using the 
rate of 3.0 lb ai/A resulted in an MOE of 5,300. The MOEs for object-
to-mouth and soil ingestion exposure were 85,000 and 67,000 
respectively.
    A Tier I aggregate exposure estimate for adults (consisting of 
dermal exposure only) resulted in a total MOE of 740 which is greater 
than the level of concern of 300 and therefore not of concern. The 
adult total MOE of 740 was based on using the TTR from California test 
site and 3% dermal absorption factor. Since the California test site 
resulted in the lowest dermal MOE, it was determined to represent the 
worst case scenario. In assessing the aggregate residential exposure 
for children, The Agency also used the California TTR data, hand press 
data and 3% dermal absorption factor for determining dermal exposure to 
children. This resulted in a total MOE (dermal + oral) of 410 for an 
application rate of 2 lb ai/acre and 400 for an application rate of 3 
lb ai/acre, both of which are greater than 300 and therefore not 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 pendimethalin and any 
other substances and pendimethalin 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 pendimethalin 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/
.

D. Safety Factor for Infants and Children

    In general, section 408 of FFDCA provides that EPA shall apply an 
additional tenfold margin of safety for infants and children in the 
case of threshold effects to account for prenatal and postnatal 
toxicity and the completeness of the data base on toxicity and exposure 
unless EPA determines based on reliable data 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 UF (safety) in calculating a dose level 
that poses no appreciable risk to humans. In applying this provision, 
EPA either retains the default value of 10X when reliable data do not 
support the choice of a different factor, or, if reliable data are 
available, EPA uses a different additional safety factor value based on 
the use of traditional UFs and/or FQPA data safety factors, as 
appropriate.
    The data base for pendimethalin does not indicate a potential for 
increased toxicological sensitivity from either prenatal or postnatal 
exposures. No developmental toxicity was observed in either the rat or 
rabbit developmental toxicity studies, nor was there evidence in the 
two-generation reproduction study of developmental or reproductive 
toxicity at dose levels below those in which parental toxicity was 
observed. There was no neurotoxicity observed in the submitted toxicity 
studies, and therefore a developmental neurotoxicity (DNT) study is not 
required.
    Available data show the thyroid is a target organ for 
pendimethalin. The endpoints and doses selected for risk assessment 
were based on the most sensitive effect, thyroid toxicity, which was 
well-characterized in both chronic and subchronic toxicity studies on 
the basis of clear NOAELs and LOAELs. In addition, the exposure data 
used to evaluate risks for the general U.S. population and infants and 
children are conservative, and therefore, the calculated risks are 
considered to be protective. Since thyroid toxicity parameters were not 
measured in the developmental toxicity studies, the Agency has required 
additional data on comparative thyroid toxicity in young and adult 
rats. The Agency has retained a data base UF for the lack of the study, 
to be applied in determining residential and aggregate risks. The 
Agency has removed the Special FQPA Safety Factor (i.e., reduced it to 
1X) because there was no evidence of qualitative or quantitative 
susceptibility in the submitted data, and because the endpoints and 
doses selected for risk assessment were based on thyroid effects. There 
is a concern that perturbation of thyroid homeostatis may lead to 
hypothyroidism, and possibly result in adverse effects on the 
developing nervous system. The Agency has requested a developmental 
thyroid assay be conducted to evaluate the impact of pendimethalin on 
thyroid hormones, structure, and/or thyroid hormone homeostasis during 
development.

E. Aggregate Risks and Determination of Safety

    1. Acute aggregate risk. No toxic effects attributable to a single 
dose were identified for pendimethalin. Therefore, an acute risk is not 
anticipated for this chemical.
    2. Short-term Aagregate risk. In estimating short-term aggregate 
risk, the chronic dietary (food) exposure estimate and the total non-
dietary (residential) exposure estimate have been combined for adults 
and children. The chronic dietary exposure estimate reflects average 
dietary exposure and serves as an estimate of dietary exposure that co-
occurs with potential short-term non-dietary exposure to adults and 
children. The short-term aggregate exposures for adults and children at 
application rates of 3 and 2 lbs ai/acre were greater than the EDWC for 
ground water or surface water and therefore, were not of concern. 
Short-term aggregate risk estimates for pendimethalin are summarized in 
the following Table 2.

[[Page 18633]]

                                               Table 2.--Short-Term Aggregate Risk and DWLOC Calculations
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                          Average Food       Residential       Aggregate MOE        Max Water         Ground      Surface     Short-Term
              Population                Exposure mg/kg/    Exposure1 mg/kg/      (food and       Exposure3 mg/kg/   Water EDWC   Water EDWC     DWLOC4
                                              day                day           residential)2           day            (ppb)        (ppb)       ([mu]/L)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Adult male (U.S. population)                    0.000710              0.014                699           0.013600        0.024            5          476
--------------------------------------------------------------------------------------------------------------------------------------------------------
Adult Female (Females 13+)                      0.000473              0.016                607           0.016000        0.024            5          480
--------------------------------------------------------------------------------------------------------------------------------------------------------
Child (1-2 years) 21b rate                      0.001787              0.024                383           0.024300        0.024            5          243
--------------------------------------------------------------------------------------------------------------------------------------------------------
Child (1-2 years) 31b rate                                            0.025                370           0.006300        0.024            5           95
--------------------------------------------------------------------------------------------------------------------------------------------------------
Target MOE = 300 based on a total UF of 100 (10X intraspecies, 3X interspecies).
Maximum Exposure (mg/kg/day) = NOAEL(10 mg/kg/day)/Target MOE (300)
1Residential Exposure = [Oral exposure + Dermal exposure + Inhalation Exposure]
2Aggregate MOE = [NOAEL / (Avg Food Exposure + Residential Exposure)]
3Maximum Water Exposure (mg/kg/day) = Target Maximum Exposure - (Food Exposure + Residential Exposure)
4DWLOC([mu]/L) = [maximum water exposure (mg/kg/day) x body weight (kg)]/ [water consumption (L) x 10-3 (microgram)]
Body Weight = 70 kg for adults, 10 Kg for children; Water consumption = 2L for adults, 1L for children.

    3. Intermediate-term aggregate risk. Based on the currently 
requested uses, there are no scenarios that are likely to result in 
intermediate-term exposure (30 to 180 days, continuous). Therefore, an 
intermediate-term risk assessment for pendimethalin has not been 
conducted.
    4. Long-term aggregate risk. The dietary exposure pathway is the 
only source of exposure to pendimethalin that is expected to be long-
term (180 to 365 days). Therefore, the long term aggregate exposure 
estimates are equivalent to the chronic dietary exposure estimates 
discussed in the previous section. The chronic aggregate exposure is 
provided in Table 3 for convenience. The most highly exposed population 
subgroup from exposure to pendimethalin in food was children 1 to 2 
years old. The chronic exposure estimate of approximately 0.002 mg/kg/
day corresponds to 6% of cPAD. Risks for the general U.S. population 
(2.4% cPAD) and all other population subgroups were lower. For all 
population subgroups, the chronic DWLOC is greater than the chronic 
ground and surface water EDWC; therefore, aggregate chronic exposure to 
pendimethalin is not expected to exceed the level of concern.

                                 Table 3.--Aggregate Risk Assessment for Chronic (Non-Cancer) Exposure to Pendimethalin.
--------------------------------------------------------------------------------------------------------------------------------------------------------

                                                   --------------------------------------------------------------------------------------------------------
      Population Subgroup         Chronic Scenario                        Chronic Food    Max Chronic Water                                        Chronic
                                                      cPAD mg/kg/day    Exposure mg/kg/    Exposure mg/kg/   Ground Water EDWC    Surface Water     DWLOC
                                                                              day                day1              (ppb)2          EDWC (ppb)2      (ppb)3
------------------------------------------------------------------------------------------------------------------------------------------------- ---------
U.S. population                               0.03           0.000710            0.02929              0.024                4.8               1025
--------------------------------------------------------------------------------------------------------------------------------------------------------
All Infants (< 1 year old)                                   0.0001295            0.02987                                                      448
--------------------------------------------------------------------------------------------------------------------------------------------------------
Children 1-2 years                                           0.001787           0.028213                                                      423
--------------------------------------------------------------------------------------------------------------------------------------------------------
Children 3-5 years                                           0.001608             0.0284                                                      426
--------------------------------------------------------------------------------------------------------------------------------------------------------
Children 6-12                                                0.001105           0.028895                                                      433
--------------------------------------------------------------------------------------------------------------------------------------------------------
Youth 13-19                                                  0.000742            0.02926                                                     1024
--------------------------------------------------------------------------------------------------------------------------------------------------------
Adults 20-49                                                 0.000558           0.029442                                                     1030
--------------------------------------------------------------------------------------------------------------------------------------------------------
Females 13+                                                  0.000473             0.0295                                                      885
--------------------------------------------------------------------------------------------------------------------------------------------------------
Adults 50+ years                                             0.000556             0.0294                                                     1029
--------------------------------------------------------------------------------------------------------------------------------------------------------
1Maximum chronic water exposure (mg/kg/day) = [chronic PAD (mg/kg/day) - chronic dietary exposure (mg/kg/day)]
2 See section 2 for estimated surface water and ground water concentrations
3Chronic DWLOC([mu]/L) = [maximum chronic water exposure (mg/kg/day) x body weight (kg)]/[water consumption (L) x 10-3 mg/[mu]]

[[Page 18634]]

Body weights (70 kg adult male; 60 kg adult female; 10 kg child)

    5. Cancer aggregate risk. As discussed above the Agency determined 
that the 0.10 mg/kg/day RfD for chronic risks, is protective of both 
the chronic, non-carcinogenic effects as well as the carcinogenic 
effect seen in the rat. Accordingly, based on the risk estimates for 
chronic risk above, EPA concludes that aggregate chronic exposure to 
pendimethalin is not expected to pose a cancer risk of 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 pendimethalin and its metabolite residues.

IV. Other Considerations

A. Analytical Enforcement Methodology

    Adequate methods are available for data collection and tolerance 
enforcement for existing and proposed uses of pendimethalin. Methods I 
through IV in the Pesticide Analytical Manuel (PAM) Vol. II are gas 
chromatography/electron capture (GC/ECD) methods. Methods used for data 
collection are essentially the same as the PAM Vol. II methods, and 
have been adequately validated.
    The Food and Drug Administration's PESTDATA data base (PAM Volume 
I, Appendix I) indicates that pendimethalin is completely recovered 
(>80%) by Multiresidue Methods Section 302 (Luke method; Protocol D) 
and 303 (Mills, Onley, Gaither method; Protocol E, nonfatty), and 
partially recovered (50-80%) by Multiresidue Method Section 304 (Mills 
fatty food method; Protocol E, fatty).
    The method may be requested from: Chief, Analytical Chemistry 
Branch, Environmental Science Center, 701 Mapes Rd., Ft. Meade, MD 
20755-5350; telephone number: (410) 305-2905; e-mail address: 
residuemethods@epa.gov.

B. International Residue Limits

    There are no established or proposed Codex Maxium Residue Levels 
(MRLs) for pendimethalin residues. Therefore, there are no questions of 
compatibility with respect to Codex MRLs and U.S. tolerances.

V. Conclusion

    Therefore, the tolerance is established for combined residues of 
pendimethalin, [N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzenamine, 
and its metabolite 4-[(1-ethylpropyl)amino]-2-methyl-3,5-dinitrobenyzl 
alcohol, in or on carrots at 0.5 ppm; peppermint, tops and spearmint, 
tops at 0.2 ppm; peppermint, oil and spearmint, oil at 1.0 ppm; fruit, 
citrus, group 10 at 0.1 ppm; citrus, oil at 0.5 ppm; almond, hulls at 
0.4 ppm; and nuts, tree, group 14 at 0.1 ppm.

VI. Objections and Hearing Requests

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

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

    You must file your objection or request a hearing on this 
regulation in accordance with the instructions provided in this unit 
and in 40 CFR part 178. To ensure proper receipt by EPA, you must 
identify docket ID number EPA-HQ-OPP-2005-0056 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 June 12, 
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 14th 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 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 ADDRESSES. Mail your 
copies, identified by docket ID number EPA-HQ-OPP-2005-0056, 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).

[[Page 18635]]

VII. Statutory and Executive Order Reviews

    This final rule establishes a tolerance under section 408(d) of 
FFDCA 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, 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 
petition under section 408(d) of FFDCA, such as the tolerance in this 
final rule, do not require the issuance of a proposed rule, the 
requirements of the Regulatory Flexibility Act (RFA) (5 U.S.C. 601 et 
seq.) do not apply. In addition, the Agency has determined that this 
action will not have a substantial direct effect on States, on the 
relationship between the national government and the States, or on the 
distribution of power and responsibilities among the various levels of 
government, as specified in Executive Order 13132, entitled Federalism 
(64 FR 43255, August 10, 1999). Executive Order 13132 requires EPA to 
develop an accountable process to ensure ``meaningful and timely input 
by State and local officials in the development of regulatory policies 
that have federalism implications.'' ``Policies that have federalism 
implications'' is defined in the Executive Order to include regulations 
that have ``substantial direct effects on the States, on the 
relationship between the national government and the States, or on the 
distribution of power and responsibilities among the various levels of 
government.'' This final rule directly regulates growers, food 
processors, food handlers and food retailers, not States. This action 
does not alter the relationships or distribution of power and 
responsibilities established by Congress in the preemption provisions 
of section 408(n)(4) of 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.

VIII. 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: March 30, 2006.
Lois Rossi,
Director, Registration Division, Office of Pesticide Programs.

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

PART 180--[AMENDED]

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

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

0
2. Section 180.361 is amended by alphabetically adding commodities to 
the table in paragraph (a) to read as follows:

Sec.  180.361  Pendimethalin, Tolerance for Residues.

    (a) * * *

------------------------------------------------------------------------
                                                              Parts per
                         Commodity                             million
------------------------------------------------------------------------
Almond, hulls..............................................          0.4
                                * * * * *
Carrots....................................................          0.5
                                * * * * *
Citrus, oil................................................          0.5
                                * * * * *
Fruit, citrus, group 10....................................          0.1
                                * * * * *
Nut, tree, group 14........................................          0.1
                                * * * * *
Peppermint, oil............................................          1.0
Peppermint, tops...........................................          0.2
                                * * * * *
Spearmint, oil.............................................          1.0
Spearmint, tops............................................          0.2
------------------------------------------------------------------------

* * * * *
[FR Doc. 06-3460 Filed 4-11-06; 8:45 am]

BILLING CODE 6560-50-S