[Federal Register: September 24, 2008 (Volume 73, Number 186)]
[Rules and Regulations]
[Page 54963-54969]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr24se08-11]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
[EPA-HQ-OPP-2008-0405; FRL-8368-8]
Pendimethalin; Pesticide Tolerances
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
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SUMMARY: This regulation establishes tolerances 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-dinitrobenzyl alcohol, in or on crayfish at 0.05 parts per
million (ppm), and cotton gin byproducts at 3.0 ppm. BASF Corporation
requested these tolerances under the Federal Food, Drug, and Cosmetic
Act (FFDCA).
DATES: This regulation is effective September 24, 2008. Objections and
requests for hearings must be received on or before November 24, 2008,
and must be filed in accordance with the instructions provided in 40
CFR part 178 (see also Unit I.C. of the SUPPLEMENTARY INFORMATION).
ADDRESSES: EPA has established a docket for this action under docket
identification (ID) number EPA-HQ-OPP-2008-0405. To access the
electronic docket, go to http://www.regulations.gov, select ``Advanced
Search,'' then ``Docket Search.'' Insert the docket ID number where
indicated and select the ``Submit'' button. Follow the instructions on
the regulations.gov website to view the docket index or access
available documents. All documents in the docket are listed in the
docket index available in regulations.gov. Although listed in the
index, some information is not publicly available, e.g., Confidential
Business Information (CBI) or other information whose disclosure is
restricted by statute. Certain other material, such as copyrighted
material, is not placed on the Internet and will be publicly available
only in hard copy form. Publicly available docket materials are
available in the electronic docket at http://www.regulations.gov, or,
if only available in hard copy, at the OPP Regulatory Public Docket in
Rm. S-4400, One Potomac Yard (South Bldg.), 2777 S. Crystal Dr.,
Arlington, VA. The Docket Facility is open from 8:30 a.m. to 4 p.m.,
Monday through Friday, excluding legal holidays. The Docket Facility
telephone number is (703) 305-5805.
FOR FURTHER INFORMATION CONTACT: Jim Tompkins, Registration Division
(7505P), Office of Pesticide Programs, Environmental Protection Agency,
1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone
number: (703) 305-5697; 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 those
engaged in the following activities:
Crop production (NAICS code 111).
Animal production (NAICS code 112).
Food manufacturing (NAICS code 311).
Pesticide manufacturing (NAICS code 32532).
This listing is not intended to be exhaustive, but rather to
provide a guide
[[Page 54964]]
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?
In addition to accessing an electronic copy of this Federal
Register document through the electronic docket at http://
www.regulations.gov, you may access this Federal Register document
electronically through the EPA Internet under the ``Federal Register''
listings at http://www.epa.gov/fedrgstr. You may also access a
frequently updated electronic version of EPA's tolerance regulations at
40 CFR part 180 through the Government Printing Office's pilot e-CFR
site at http://www.gpoaccess.gov/ecfr.
C. Can I File an Objection or Hearing Request?
Under section 408(g) of FFDCA, any person may file an objection to
any aspect of this regulation and may also request a hearing on those
objections. You must file your objection or request a hearing on this
regulation in accordance with the instructions provided in 40 CFR part
178. To ensure proper receipt by EPA, you must identify docket ID
number EPA-HQ-OPP-2008-0405 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 as required by 40 CFR part 178 on or
before November 24, 2008.
In addition to filing an objection or hearing request with the
Hearing Clerk as described in 40 CFR part 178, please submit a copy of
the filing that does not contain any CBI for inclusion in the public
docket that is described in ADDRESSES. Information not marked
confidential pursuant to 40 CFR part 2 may be disclosed publicly by EPA
without prior notice. Submit this copy, identified by docket ID number
EPA-HQ-OPP-2008-0405, by one of the following methods:
Federal eRulemaking Portal: http://www.regulations.gov.
Follow the on-line instructions for submitting comments.
Mail: Office of Pesticide Programs (OPP) Regulatory Public
Docket (7502P), Environmental Protection Agency, 1200 Pennsylvania
Ave., NW., Washington, DC 20460-0001.
Delivery: OPP Regulatory Public Docket (7502P),
Environmental Protection Agency, Rm. S-4400, One Potomac Yard (South
Bldg.), 2777 S. Crystal Dr., Arlington, VA. Deliveries are only
accepted during the Docket's normal hours of operation (8:30 a.m. to 4
p.m., Monday through Friday, excluding legal holidays). Special
arrangements should be made for deliveries of boxed information. The
Docket Facility telephone number is (703) 305-5805.
II. Petition for Tolerance
In the Federal Register of June 13, 2008 (73 FR 33814) (FRL-8367-
3), EPA issued a notice pursuant to section 408(d)(3) of FFDCA, 21
U.S.C. 346a(d)(3), announcing the filing of a pesticide petition (PP
6F7098) by BASF Corporation, 26 Davis Drive, Research Triangle Park, NC
27709. The petition requested that 40 CFR 180.361 be amended by
establishing tolerances 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-
dinitrobenzyl alcohol, in or on crayfish at 0.05 ppm, and cotton
byproducts at 3.0 ppm. That notice referenced a summary of the petition
prepared by BASF Corporation, the registrant, which is available to the
public in the docket, http://www.regulations.gov. No comments were
received on the notice of filing.
III. Aggregate Risk Assessment and Determination of Safety
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 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. . .
.''
Consistent with section 408(b)(2)(D) of FFDCA, and the factors
specified in 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 for the petitioned-for
tolerances 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-dinitrobenzyl alcohol, in or on
the raw agricultural commodity crayfish at 0.05 ppm, and cotton
byproducts at 3.0 ppm. EPA's assessment of exposures and risks
associated with establishing tolerances 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.
Pendimethalin has low acute oral, dermal, and inhalation toxicity.
The thyroid is a target organ for pendimethalin in chronic studies.
Thyroid toxicity in chronic and subchronic rat and mouse studies was
manifested as alterations in thyroid hormones (decreased Total T4, and
T3, increased percent of free T4 and T3) increased thyroid weight, and
microscopic thyroid lesions (including increased thyroid follicular
cell height, follicular cell hyperplasia, as well as follicular cell
adenomas).
The data provided no indication of increased susceptibility
following pre-/postnatal exposure in the two-generation reproduction
study in rats. 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 cancer risk assessment approach is being
followed 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 chronic risk assessment is considered
to be protective of any cancer effects.
[[Page 54965]]
B. Toxicological Endpoints
For hazards that have a threshold below which there is no
appreciable risk, a toxicological point of departure (POD) is
identified as the basis for derivation of reference values for risk
assessment. The POD may be defined as the highest dose at which no
adverse effects are observed (the NOAEL) in the toxicology study
identified as appropriate for use in risk assessment. However, if a
NOAEL cannot be determined, the lowest dose at which adverse effects of
concern are identified (the LOAEL) or a Benchmark Dose (BMD) approach
is sometimes used for risk assessment. Uncertainty/safety factors (UFs)
are used in conjunction with the POD to take into account 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. Safety is assessed for acute and chronic
dietary risks by comparing aggregate food and water exposure to the
pesticide to the acute population adjusted dose (aPAD) and chronic
population adjusted dose (cPAD). The aPAD and cPAD are calculated by
dividing the POD by all applicable UFs. Aggregate short-, intermediate-
, and chronic-term risks are evaluated by comparing food, water, and
residential exposure to the POD to ensure that the margin of exposure
(MOE) called for by the product of all applicable UFs is not exceeded.
This latter value is referred to as the Level of Concern (LOC).
For non-threshold risks, the Agency assumes that any amount of
exposure will lead to some degree of risk. Thus, the Agency estimates
risk in terms of the probability of an occurrence of the adverse effect
greater than that expected in a lifetime. For more information on the
general principles EPA uses in risk characterization and a complete
description of the risk assessment process, see http://www.epa.gov/
pesticides/factsheets/riskassess.htm.
A summary of the toxicological endpoints for chemical name used for
human risk assessment is shown in the table of this unit.
Table 1.--Summary of Toxicological Doses and Endpoints for the Herbicide Pendimethalin, N-(1-ethylpropyl)-3,4-
dimethyl-2,6-dinitrobenzenamine, and Its Metabolite, 4-[(1-ethylpropyl) amino]-2-methyl-3,5-dinitrobenzyl
alcohol, for Use in Human Risk Assessment
----------------------------------------------------------------------------------------------------------------
RfD, PAD, Level of Study and
Exposure Scenario Point of Departure Dose Used in Risk Concern for Risk Toxicological
Assessment, UF Assessment Effects
----------------------------------------------------------------------------------------------------------------
Acute Dietary NA NA NA No appropriate
(Females 13-49)................. acute endpoint
(General U.S population)........ identified for
these groups.
There were no
toxic effects
attributable to a
single dose.
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Chronic Dietary NOAEL = 10 mg/kg/ UFH = 10X Chronic RfD = 0.03 92-day thyroid
(All populations)............... day UFA = 3X.......... mg/kg/day function study in
Chronic RfD = 0.03 UFDB = 10X........ cPAD = Chronic/RfD rats; 56-day
mg/kg/day. Total UF = 300X... cPAD = 0.03 mg/kg/ thyroid study in
day. rats; 14-day
intra thyroid
metabolism study
in rats.
LOAEL = 31 mg/kg/
day based on
hormonal and
histopathological
changes in the
thyroid.
----------------------------------------------------------------------------------------------------------------
Incidental Oral Short-Term NOAEL = 10 mg/kg/ UFH = 10X Residential LOC = 92-day thyroid
(1-30 days)..................... day UFA = 3X.......... 300 function study in
Intermediate-Term............... UFDB = 10X........ rats; 56-day
(1-6 months).................... Total UF = 300X... thyroid study in
rats; 14-day
intra thyroid
metabolism study
in rats.
LOAEL = 31 mg/kg/
day based on
hormonal and
histopathological
changes in the
thyroid.
----------------------------------------------------------------------------------------------------------------
Dermal Short-Term NOAEL = 10 mg/kg/ UFH = 10X Residential LOC = 92-day thyroid
(1-30 days)..................... day UFA = 3X.......... 300 function study in
Intermediate-Term............... UFDB = 10X........ rats; 56-day
(1-6 months).................... Total UF = 300X... thyroid study in
Long-Term....................... Dermal Absorption rats; 14-day
(> 6 months).................... = 3%. intra thyroid
metabolism study
in rats.
LOAEL = 31 mg/kg/
day based on
hormonal and
histopathological
changes in the
thyroid.
----------------------------------------------------------------------------------------------------------------
Inhalation Short-Term NOAEL = 10 mg/kg/ UFH = 10X Residential LOC = 92-day thyroid
(1-30 days)..................... day UFA = 3X.......... 300 function study in
Intermediate-Term............... UFDB = 10X........ rats; 56-day
(1-6 months).................... Total UF = 300X.. thyroid study in
Long-Term....................... Inhalation rats; 14-day
(> 6 months).................... toxicity is intra thyroid
assumed to be metabolism study
equivalent to in rats.
oral toxicity.. LOAEL = 31 mg/kg/
day based on
hormonal and
histopathological
changes in the
thyroid.
----------------------------------------------------------------------------------------------------------------
Cancer Pendimethalin is classified as a Group C possible human 2-year chronic/
(Oral, dermal, inhalation)...... carcinogen. The chronic dietary assessment using the cPAD carcinogenicity
is considered to be protective of cancer effects. study in rats.
----------------------------------------------------------------------------------------------------------------
Point of Departure (POD) = A data point or an estimated point that is derived from observed dose-response data
and used to mark the beginning of extrapolation to determine risk associated with lower environmentally
relevant human exposures. NOAEL = no observed adverse effect level. LOAEL = lowest observed adverse effect
level. UF = uncertainty factor. UFA = extrapolation from animal to human (interspecies). UFH = potential
variation in sensitivity among members of the human population (intraspecies). UFDB = to account for the
absence of key data (i.e., lack of a critical study). FQPA SF = FQPA Safety Factor. PAD = population adjusted
dose (a = acute, c = chronic). RfD = reference dose. MOE = margin of exposure. LOC = level of concern. N/A =
not applicable.
[[Page 54966]]
C. Exposure Assessment
1. Dietary exposure from food and feed uses. In evaluating dietary
exposure to the herbicide pendimethalin, and its metabolite (CL
202347), EPA considered exposure under the petitioned-for tolerances as
well as all existing tolerances for the herbicide pendimethalin, and
its metabolite (CL 202347) in 40 CFR 180.361. EPA assessed dietary
exposures from the herbicide pendimethalin, and its metabolite (CL
202347) 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
the herbicide pendimethalin, and its metabolite (CL 202347); therefore,
a quantitative acute dietary exposure assessment is unnecessary.
ii. Chronic exposure. In conducting this chronic dietary risk
assessment of the dietary Exposure Evaluation Model (DEEM\TM\) analysis
evaluated the individual food consumption as reported by respondents in
the United States 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
percent crop treated (PCT)). These assumptions result in highly
conservative estimates of dietary exposure and risk.
iii. Cancer. Pendimethalin is classified as a ``Group C[rdquo,]
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 protection for the pre-
cancerous effect on the thyroid.
iv. Anticipated residue and PCT information. EPA did not use
anticipated residue and/or PCT information in the dietary assessment
for the herbicide pendimethalin. Tolerance level residues and/or 100
PCT were assumed for all food commodities.
2. Dietary exposure from drinking water. The Agency used screening
level water exposure models in the dietary exposure analysis and risk
assessment for in drinking water. These simulation models take into
account data on the physical, chemical, and fate/transport
characteristics of the herbicide pendimethalin. Further information
regarding EPA drinking water models used in pesticide exposure
assessment can be found at http://www.epa.gov/oppefed1/models/water/
index.htm.
Based on the Pesticide Root Zone Model/Exposure Analysis Modeling
System (PRZM/EXAMS) and Screening Concentration in Ground Water (SCI-
GROW) models, drinking water concentrations (EDWCs) of the herbicide
pendimethalin were estimated.
Modeled estimates of drinking water concentrations were directly
entered into the dietary exposure model. For acute dietary risk
assessment, the water concentration value of 77.7 parts per billion
(ppb) was used to assess the contribution to drinking water.
For chronic dietary risk assessment, the water concentration of
value 6 ppb was used to assess the contribution to drinking 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).
Pendimethalin is currently registered for the following residential
non-dietary sites: Landscape, grounds plantings, ornamental crops, turf
grass, and lawns. EPA assessed residential exposure using the following
assumptions: Exposures are short-term in duration, and consist of
dermal (for adults and children), and oral (hand-to-mouth, object-to-
mouth, and soil ingestion, for children only). 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. The LOC for oral,
dermal and inhalation exposure is an MOE of less than 300. The
residential exposure estimate for adults, consisting of dermal exposure
only, results in a total MOE of 740, and is therefore not of concern.
The residential exposure for children results in a total MOE (dermal +
oral) of 410 at an application rate of 2 lb ai/acre, and an MOE of 400
for an application rate of 3 lb ai/acre. Residential aggregate exposure
is not of concern.
4. Cumulative effects from substances with a common mechanism of
toxicity. Section 408(b)(2)(D)(v) of FFDCA requires that, when
considering whether to establish, modify, or revoke a tolerance, the
Agency consider ``available information'' concerning the cumulative
effects of a particular pesticide's residues and ``other substances
that have a common mechanism of toxicity.''
Unlike other pesticides for which EPA has followed a cumulative
risk approach based on a common mechanism of toxicity, EPA has not made
a common mechanism of toxicity finding as to 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
1. In general. Section 408(b)(2)(c) of FFDCA provides that EPA
shall apply an additional tenfold (10X) 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 database on toxicity
and exposure unless EPA determines based on reliable data that a
different margin of safety will be safe for infants and children. This
additional margin of safety is commonly referred to as the FQPA safety
factor (SF). In applying this provision, EPA either retains the default
value of 10X, or uses a different additional safety factor when
reliable data available to EPA support the choice of a different
factor.
2. Prenatal and postnatal sensitivity. The data base for
pendimethalin does not indicate a potential for increased toxicological
sensitivity from either prenatal or postnatal exposures. No
[[Page 54967]]
developmental toxicity was observed in either the rat or rabbit
developmental toxicity studies, nor was there evidence in the 2-
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.
3. Conclusion. EPA has determined that the FQPA safety factor of
10X must be retained. This decision is based on the following findings:
i. The toxicity database for pendimethalin contains all of the
standard toxicity studies. However, there is uncertainty regarding
potential thyroid effects seen in some of these studies. Based on the
hormonal changes (alterations in thyroid weights and histopathological
lesions) observed in several studies following oral administration of
pendimethalin, it is likely that pendimethalin 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, EPA has
recommended that a developmental thyroid assay be conducted to evaluate
the impact of pendimethalin on thyroid hormones, structure, and/or
thyroid hormone homeostasis during development. This study has not yet
been submitted.
ii. There is no indication that pendimethalin is a neurotoxic
chemical and there is no need for a developmental neurotoxicity study
or additional UFs to account for neurotoxicity.
iii. There is no evidence that pendimethalin results in increased
susceptibility in in utero rats or rabbits in the prenatal
developmental studies or in young rats in the 2-generation reproduction
study. However, the developmental studies were not adequate to fully
assess the potential for susceptibility. Consequently, there is concern
for potential increased sensitivity or susceptibility in offspring
regarding thyroid effects.
iv. There are no residual uncertainties identified in the exposure
databases. The dietary food exposure assessments were performed based
on 100 PCT and tolerance-level residues. Conservative ground and
surface water modeling estimates were used. Similarly, conservative
Residential SOPs were used to assess post-application exposure of
children as well as incidental oral exposure of toddlers. These
assessments will not underestimate the exposure and risks posed by
pendimethalin.
Although the exposure estimate is very conservative and there are
no neurotoxic concerns for pendimethalin, there is sufficient
uncertainty regarding thyroid effects, particularly thyroid effects in
the young, that EPA is retaining the 10X FQPA safety factor. EPA has
also determined that the traditional 10X uncertainty factor to account
for interspecies variation may be reduced to 3X, since it has been
established that rats are more susceptible to thyroid effects than
humans. These factors, together with the traditional 10X uncertainty
factor to account for intraspecies variation, result in a total
uncertainty factor of 300X (10X, 3X, and 10X).
E. Aggregate Risks and Determination of Safety
EPA determines whether acute and chronic pesticide exposures are
safe by comparing aggregate exposure estimates to the aPAD and cPAD.
The aPAD and cPAD represent the highest safe exposures, taking into
account all appropriate SFs. EPA calculates the aPAD and cPAD by
dividing the POD by all applicable UFs. For linear cancer risks, EPA
calculates the probability of additional cancer cases given the
estimated aggregate exposure. Short-, intermediate-, and chronic-term
risks are evaluated by comparing the estimated aggregate food, water,
and residential exposure to the POD to ensure that the MOE called for
by the product of all applicable UFs is not exceeded.
1. Acute risk. No toxic effects attributable to a single dose were
identified for pendimethalin. Therefore, a quantitative acute risk
assessment was not conducted for pendimethalin.
2. Chronic risk. The dietary exposure (food and drinking water)
pathway is the only source of exposure to pendimethalin that is
expected to be of long term (180 to 365 days). Therefore, the long-term
aggregate exposure and risk estimates are equivalent to the chronic
dietary exposure and risk estimates.
Using the exposure assumptions described in this unit for chronic
exposure, EPA has concluded that chronic exposure to the herbicide
pendimethalin from food and water will utilize 15% of the cPAD for
(children 1-2 years of age) the population group receiving the greatest
exposure. Based on the explanation in Unit III.C.3., regarding
residential use patterns, chronic residential exposure to residues of
the herbicide pendimethalin is not expected.
3. Short-term risk. Short-term aggregate exposure takes into
account short-term residential exposure plus chronic exposure to food
and water (considered to be a background exposure level).
The herbicide pendimethalin is currently registered for uses that
could result in short-term residential exposure and the Agency has
determined that it is appropriate to aggregate chronic exposure through
food and water with short-term residential exposures to the herbicide
pendimethalin.
Using the exposure assumptions described in this unit for short-
term exposures, EPA has concluded the combined short-term food, water,
and residential exposures aggregated result in aggregate MOEs of the
level of concern for oral, dermal, and inhalation exposure is an MOE of
less than 300. The short-term aggregate exposure estimate for adult
males results in an aggregate MOE of 650, while the short-term
aggregate exposure estimate for adult females results in an aggregate
MOE of 580. The aggregate exposure estimate for children results in a
total MOE of 350 at an application rate (to residential turf) of 2 lbs
ai/A, and a total MOE of 340 for an application rate of 3 lbs ai/A.
Aggregate exposure is therefore not of concern for any of the
population subgroups.
4. Intermediate-term risk. Intermediate-term aggregate exposure
takes into account intermediate-term residential exposure plus chronic
exposure to food and water (considered to be a background exposure
level).
The herbicide pendimethalin is not registered for any use patterns
that would result in intermediate-term residential exposure. Therefore,
the intermediate-term aggregate risk is the sum of the risk from
exposure to the herbicide pendimethalin through food and water, which
has already been addressed, and will not be greater than the chronic
aggregate risk.
5. Aggregate cancer risk for U.S. population. EPA classified
pendimethalin as a ``Group C'' (possible human) carcinogen 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. EPA is following a non-quantitative
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 cells. The chronic risk assessment is considered
to be protective of any
[[Page 54968]]
cancer effects; therefore, a separate quantitative cancer aggregate
risk assessment was not conducted.
6. Determination of safety. Based on these risk assessments, EPA
concludes that there is a reasonable certainty that no harm will result
to the general population, or to infants and children from aggregate
exposure to the herbicide pendimethalin 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).
Adequate enforcement methodology liquid chromatography/mass
spectrometry (LC/MS/MS) is available to enforce the tolerance
expression. The method may be requested from: Chief, Analytical
Chemistry Branch, Environmental Science Center, 701 Mapes Rd., Ft.
Meade, MD 20755-5350; telephone number: (410) 305-2905; e-mail address:
residuemethods@epa.gov.
B. International Residue Limits
There 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.
C. Revisions to Petitioned-For Tolerances
Based on the submitted data, residues of pendimethalin in rice
processed commodities are not expected to exceed those found in rice
grain. Therefore, a tolerance for rice processing fraction at 0.1 ppm
is not necessary.
V. Conclusion
Therefore, tolerances are established for combined residues of the
herbicide pendimethalin, N-(1-ethylpropyl)-3,4-dimethyl-2,6- dinitro-
benzenamine, and its metabolite, 4-[(1-ethylpropyl) amino]-2-methyl-
3,5-dinitrobenzyl alcohol, in or on cotton, gin byproducts at 3.0 ppm,
and crayfish at 0.05 ppm.
VI. Statutory and Executive Order Reviews
This final rule establishes tolerances 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 final rule has been
exempted from review under Executive Order 12866, this final rule is
not subject to Executive Order 13211, entitled Actions Concerning
Regulations That Significantly Affect Energy Supply, Distribution, or
Use (66 FR 28355, May 22, 2001) or Executive Order 13045, entitled
Protection of Children from Environmental Health Risks and Safety Risks
(62 FR 19885, April 23, 1997). 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., 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).
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.
This final rule directly regulates growers, food processors, food
handlers, and food retailers, not States or tribes, nor does this
action alter the relationships or distribution of power and
responsibilities established by Congress in the preemption provisions
of section 408(n)(4) of FFDCA. As such, the Agency has determined that
this action will not have a substantial direct effect on States or
tribal governments, on the relationship between the national government
and the States or tribal governments, or on the distribution of power
and responsibilities among the various levels of government or between
the Federal Government and Indian tribes. Thus, the Agency has
determined that Executive Order 13132, entitled Federalism (64 FR
43255, August 10, 1999) and Executive Order 13175, entitled
Consultation and Coordination with Indian Tribal Governments (65 FR
67249, November 9, 2000) do not apply to this final rule. In addition,
this final rule does not 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).
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).
VII. Congressional Review Act
The Congressional Review Act, 5 U.S.C. 801 et seq., generally
provides that before a rule may take effect, the agency promulgating
the rule must submit a rule report 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: September 9, 2008.
Donald R. Stubbs,
Acting Director, Registration Division, Office of Pesticide Programs.
0
Therefore, 40 CFR chapter I is amended as follows:
PART 180--[AMENDED]
0
1. The authority citation for part 180 continues to read as follows:
Authority: 21 U.S.C. 321(q), 346a and 371.
0
2. Section 180.361 is amended by alphabetically adding the following
commodities to the table in paragraph (a) to read as follows:
Sec. 180.361 Pendimethalin, tolerance for residues.
(a) * * *
------------------------------------------------------------------------
Commodity Parts per million
------------------------------------------------------------------------
* * * * *
Cotton, gin byproducts............................... 3.0
* * * * *
Crayfish............................................. 0.05
* * * * *
------------------------------------------------------------------------
[[Page 54969]]
* * * * *
[FR Doc. E8-22434 Filed 9-23-08; 8:45 am]
BILLING CODE 6560-50-S