[Federal Register Volume 80, Number 34 (Friday, February 20, 2015)]
[Rules and Regulations]
[Pages 9209-9215]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-03458]



40 CFR Part 180

[EPA-HQ-OPP-2013-0670; FRL-9922-08]

Dimethenamid; Pesticide Tolerances

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.


SUMMARY: This regulation establishes tolerances for residues of 
dimethenamid in or on cottonseed subgroup 20C and cotton, gin 
byproducts. BASF Corporation requested these tolerances under the 
Federal Food, Drug, and Cosmetic Act (FFDCA).

DATES: This regulation is effective February 20, 2015. Objections and 
requests for hearings must be received on or before April 21, 2015, 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: The docket for this action, identified by docket 
identification (ID) number EPA-HQ-OPP-2013-0670, is available at http://www.regulations.gov or at the Office of Pesticide Programs Regulatory 
Public Docket (OPP Docket) in the Environmental Protection Agency 
Docket Center (EPA/DC), West William Jefferson Clinton Bldg., Rm. 3334, 
1301 Constitution Ave. NW., Washington, DC 20460-0001. The Public 
Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through 
Friday, excluding legal holidays. The telephone number for the Public 
Reading Room is (202) 566-1744, and the telephone number for the OPP 
Docket is (703) 305-5805. Please review the visitor instructions and 
additional information about the docket available at http://www.epa.gov/dockets.

FOR FURTHER INFORMATION CONTACT: Susan Lewis, Registration Division 
(7505P), Office of Pesticide Programs, Environmental Protection Agency, 
1200 Pennsylvania Ave. NW., Washington, DC 20460-0001; main telephone 
number: (703) 305-7090; email address: RDFRNotices@epa.gov.


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. 
The following list of North American Industrial Classification System 
(NAICS) codes is not intended to be exhaustive, but rather provides a 
guide to help readers determine whether this document applies to them. 
Potentially affected entities may include:
     Crop production (NAICS code 111).
     Animal production (NAICS code 112).
     Food manufacturing (NAICS code 311).
     Pesticide manufacturing (NAICS code 32532).

B. How can I get electronic access to other related information?

    You may access a frequently updated electronic version of EPA's 
tolerance regulations at 40 CFR part 180 through the Government 
Publishing Office's e-CFR site at http://www.ecfr.gov/cgi-bin/text-idx?&c=ecfr&tpl=/ecfrbrowse/Title40/40tab_02.tpl.

[[Page 9210]]

C. How can I file an objection or hearing request?

    Under FFDCA section 408(g), 21 U.S.C. 346a, 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-2013-0670 in the subject line on the first 
page of your submission. All objections and requests for a hearing must 
be in writing, and must be received by the Hearing Clerk on or before 
April 21, 2015. Addresses for mail and hand delivery of objections and 
hearing requests are provided in 40 CFR 178.25(b).
    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 (excluding any Confidential Business Information (CBI)) for 
inclusion in the public docket. Information not marked confidential 
pursuant to 40 CFR part 2 may be disclosed publicly by EPA without 
prior notice. Submit the non-CBI copy of your objection or hearing 
request, identified by docket ID number EPA-HQ-OPP-2013-0670, by one of 
the following methods:
     Federal eRulemaking Portal: http://www.regulations.gov. 
Follow the online instructions for submitting comments. Do not submit 
electronically any information you consider to be CBI or other 
information whose disclosure is restricted by statute.
     Mail: OPP Docket, Environmental Protection Agency Docket 
Center (EPA/DC), (28221T), 1200 Pennsylvania Ave. NW., Washington, DC 
     Hand Delivery: To make special arrangements for hand 
delivery or delivery of boxed information, please follow the 
instructions at http://www.epa.gov/dockets/contacts.html.
    Additional instructions on commenting or visiting the docket, along 
with more information about dockets generally, is available at http://www.epa.gov/dockets.

II. Summary of Petitioned-For Tolerance

    In the Federal Register of October 25, 2013 (78 FR 63938) (FRL-
9901-96), EPA issued a document pursuant to FFDCA section 408(d)(3), 21 
U.S.C. 346a(d)(3), announcing the filing of a pesticide petition (PP 
3F8197) by BASF Corporation, 26 Davis Drive, P.O. Box 13528, Research 
Triangle Park, NC 27709-3528. The petition requested that 40 CFR 
180.464 be amended by establishing tolerances for residues of the 
herbicide dimethenamid (1(RS)-2-chloro-N-[(1-methyl-2-methoxy)ethyl]-N-
(2,4-dimethylthien-3-yl)acetamide) in or on cottonseed, subgroup 20C at 
0.01 parts per million (ppm); cotton, gin byproducts at 1.5 ppm; and 
cotton, seed, refined oil at 0.02 ppm. Compliance with the tolerance 
levels is to be determined by measuring only parent. Tolerances would 
apply to either dimethenamid-P (a 90:10 mixture of S- and R-isomers, a 
mixture enriched in S-isomer) or dimethenamid (a 50:50 racemic mixture 
of S- and R-isomers). The enforcement method is not enantiomer 
specific. That document referenced a summary of the petition prepared 
by BASF Corporation, the registrant, which is available in the docket, 
http://www.regulations.gov. There were no comments received in response 
to the notice of filing.
    Based upon review of the data supporting the petition, EPA has 
determined that a separate tolerance in cotton, seed, and refined oil 
is not needed. The reason for these changes are explained in Unit IV.C.

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 FFDCA section 408(b)(2)(D), and the factors 
specified in FFDCA section 408(b)(2)(D), EPA has reviewed the available 
scientific data and other relevant information in support of this 
action. EPA has sufficient data to assess the hazards of and to make a 
determination on aggregate exposure for dimethenamid including exposure 
resulting from the tolerances established by this action. EPA's 
assessment of exposures and risks associated with dimethenamid 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 
    The existing toxicological database is comprised of studies 
conducted with both dimethenamid, which is a racemic mixture of S- and 
R-isomers (50:50, S:R), and dimethenamid-P, which is mixture of S- and 
R-isomers enriched in the S-isomer (90:10, S:R). Both sets of data for 
dimethenamid and dimethenamid-P show similar toxicity and together are 
adequate for risk assessment. Because of the similarity of the two 
mixtures, EPA relies on data for both to assess the hazard of each 
    The primary target organ is the liver. The toxicity in 90-day 
feeding studies in rats showed decreased body weights, increased 
cholesterol and changes in liver weights along with histopathology 
showing microscopic effects (centrilobular hypertrophy, periportal 
eosinophilic inclusions and necrosis) in the liver. Chronic studies in 
the rat, mouse, and dog showed decreases in body weight and food 
efficiency as accompanying effects over time. At higher dose levels, 
liver pathology (hepatic lesions, bile duct hyperplasia, and tumors), 
stomach hyperplasia, and some indications of kidney effects were noted. 
Two 21-day dermal toxicity studies in rabbits were conducted and in one 
of those studies minor skin irritation was observed at all doses tested 
and a decrease in body weight (bw) gain was also seen at the lowest 
effect level.
    The acute neurotoxicity study resulted in effects such as partially 
closed eyelids, lacrimation, and slight salivation at the highest dose 
tested of (600 milligrams/kilograms/body weight (mg/kg/bw)). There were 
no treatment-related or toxicologically significant findings during the 
gross examination of rats or in the microscopic examination of 
neurological tissues. In the subchronic neurotoxicity study, there were 
no clinical signs seen and no adverse effects seen up to 323/390 mg/kg/
bw day. Systemic effects seen were renal pelvic dilation in males 
(considered incidental) and a trend of higher liver weights in females 
was found at the lowest dose tested and

[[Page 9211]]

were not considered adverse nor were they corroborated with any other 
guideline studies submitted. There were no liver histopathology or 
clinical chemistry measurements in the subchronic neurotoxicity study; 
however, the adversity of this finding is supported by the observation 
of multiple liver effects (increased cholesterol, increased total serum 
protein, increased liver weights, and enlarged centrilobular 
hepatocytes) in the 90-day rat study at doses of 98/119 (Male/Female) 
milligrams/kilograms/day (mg/kg/day) and above. There was no 
neurotoxicity observed at higher doses nor in other guideline studies.
    Developmental toxicity studies show increased post-implantation 
loss and minor skeletal variations in the rat, and late resorptions and 
minor skeletal variations in the rabbit at the highest dose tested 
(lowest observed adverse effect level: LOAEL, 425 mg/kg/day). In the 
rabbit, the developmental effects occurred at the same dose as maternal 
toxicity (LOAEL, 150 mg/kg/day), whereas in the rat, the developmental 
toxicity occurred at much higher doses than in the dams (LOAEL, 215 mg/
kg/day). The chosen no observed adverse effect level (NOAEL) of 75 mg/
kg/day is considered protective for effects seen in both studies. The 
reproduction study resulted in decreases in body weight in both pups 
and parental animals at the same dose levels. The only other effects 
noted at the LOAEL of 150 mg/kg/day were increases in liver weights in 
both male and female parental animals.
    A review of the immunotoxicity study resulted in no immunotoxicity 
effects at the limit dose of 1,167 milligrams/kilograms (mg/kg), 
although increased absolute and relative liver weights were seen at 
this dose level. Dimethenamid-P is classified as group ``C'' possible 
human carcinogen, based on weak evidence for carcinogenicity.
    The agency concluded that quantification of cancer risk using a 
non-linear approach would adequately account for all chronic toxicity 
(including carcinogenicity) that could result from exposure to 
dimethenamid based on the following weight of evidence considerations:
    1. No statistically significant increase in liver tumors (only an 
increasing trend for liver tumors in one sex (male) and one species 
    2. No evidence of carcinogenicity in male or female mice.
    3. Equivocal evidence for mutagenicity.
    4. The POD of 5 mg/kg/day used for human health risk assessment is 
15-fold lower than the dose (75 mg/kg/day) that caused the liver tumors 
and thus considered protective for cancer.
    Specific information on the studies received and the nature of the 
adverse effects caused as well as the NOAEL and the LOAEL from the 
toxicity studies can be found at http://www.regulations.gov in document 
titled, ``Dimethenamid/Dimethenamid-P. Human Health Risk Assessment for 
Proposed New Use on Cottonseed Subgroup 20C.,'' on pg. 42-48, in docket 
ID number EPA-HQ-OPP-2013-0670.

B. Toxicological Points of Departure/Levels of Concern

    Once a pesticide's toxicological profile is determined, EPA 
identifies toxicological POD and levels of concern (LOC) to use in 
evaluating the risk posed by human exposure to the pesticide. For 
hazards that have a threshold below which there is no appreciable risk, 
the toxicological POD is used as the basis for derivation of reference 
values for risk assessment. PODs are developed based on a careful 
analysis of the doses in each toxicological study to determine the dose 
at which the NOAEL and the LOAEL are identified. Uncertainty/safety 
factors are used in conjunction with the POD to calculate a safe 
exposure level--generally referred to as a population-adjusted dose 
(PAD) or a reference dose (RfD)--and a safe margin of exposure (MOE). 
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 
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 
Dimethenamid/Dimethenamid-P used for human risk assessment is shown in 
Table 1 of this unit.

  Table 1--Summary of Toxicological Doses and Endpoints for Dimethenamid/Dimethenamid-P for Use in Human Health
                                                 Risk Assessment
                                    Point of departure
        Exposure/scenario            and uncertainty/     RfD, PAD, LOC for     Study and toxicological effects
                                      safety factors       risk assessment
Acute dietary (General population  NOAEL = 200 mg/kg/    Acute RfD = 2.0 mg/  Acute Neurotoxicity.
 including infants and children).   day                   kg/day.             LOAEL = 600 mg/kg/day based on
                                   UFA = 10x...........  aPAD = 2.0 mg/kg/     lacrimation, salivation,
                                   UFH = 10x...........   day.                 irregular and accelerated
                                   FQPA SF = 1x........                        respiration, slight tremors,
                                                                               reduced exploration, unsteady
                                                                               gait, and significantly reduced
Acute dietary (Females 13-49       NOAEL = 75 mg/kg/day  Acute RfD = 0.75 mg/ Developmental Rabbit Study
 years of age).                    UFA = 10x...........   kg/day.              Maternal. LOAEL = 150 mg/kg/day
                                   UFH = 10x...........  aPAD = 0.75 mg/kg/    based on abortions (not
                                   FQPA SF = 1x........   day.                 considered acute effect).
                                                                              Developmental; LOAEL = 150 mg/kg/
                                                                               day based on post-implantation
Chronic dietary (All populations)  NOAEL = 5 mg/kg/day   Chronic RfD = 0.05   Chronic/Carcinogenicity Rat Study.
                                   UFA = 10x...........   mg/kg/day.          LOAEL = Male/Female; 36/49 mg/kg/
                                   UFH = 10x...........  cPAD = 0.05 mg/kg/    day based on decreased body
                                   FQPA SF = 1x........   day.                 weight and body weight gain in
                                                                               both sexes, increased food
                                                                               conversion ratios in females, and
                                                                               increased microscopic hepatic
                                                                               lesions in both sexes.

[[Page 9212]]

Incidental oral short-term and     NOAEL = 10 mg/kg/day  LOC for MOE = 100..  Subchronic/Chronic Oral Dog
 intermediate-term (1 to 6         UFA = 10x...........                        Studies.
 months).                          UFH = 10x...........                       Chronic NOAEL = 10 mg/kg/day.
                                   FQPA SF = 1x........                       Chronic LOAEL = 48.7 mg/kg/day.
                                                                              Subchronic NOAEL = 4.72 mg/kg/day.
                                                                              Subchronic LOAEL = 33.6 mg/kg/day
                                                                               based on decreased body weight in
                                                                               females, increased relative to
                                                                               body liver weight in both sexes,
                                                                               increased periportal cytoplasmic
                                                                               vacuolation in liver in both
                                                                               sexes, and dilation of liver
                                                                               sinusoids in females.
Dermal short-term (1 to 30 days)   NOAEL = 300 mg/kg/    LOC for MOE = 100..  21-Day Dermal Rabbit Study.
 and intermediate-term (1-6         day                                       LOAEL = 500 mg/kg/day based on
 months).                          UFA = 10x...........                        decreased body weight gain only
                                   UFH = 10x...........                        (non-specific).
                                   FQPA SF = 1x........
Inhalation short-term (1 to 30     NOAEL = 10 mg/kg/day  LOC for MOE= 100...  Subchronic/Chronic Oral Dog
 days).                            UFA = 10x...........                        Studies.
                                   UFH = 10x...........                       Chronic NOAEL = 10 mg/kg/day.
                                   FQPA SF = 1x........                       Chronic LOAEL = 48.7 mg/kg/day.
                                                                              Subchronic NOAEL = 4.72 mg/kg/day.
                                                                              Subchronic LOAEL = 33.6 mg/kg/day
                                                                               based on decreased body weight in
                                                                               females, increased relative to
                                                                               body liver weight in both sexes,
                                                                               increased periportal cytoplasmic
                                                                               vacuolation in liver in both
                                                                               sexes, and dilation of liver
                                                                               sinusoids in females.
Cancer (Oral, dermal, inhalation)  ``C'' Possible human carcinogen. The chronic RfD is considered protective of
                                    the cancer effects.
FQPA SF = Food Quality Protection Act Safety Factor. LOAEL = lowest-observed-adverse-effect-level. LOC = level
  of concern. mg/kg/day = milligram/kilogram/day. MOE = margin of exposure. NOAEL = no-observed-adverse-effect-
  level. PAD = population adjusted dose (a = acute, c = chronic). RfD = reference dose. UFA = extrapolation from
  animal to human (interspecies). UFH = potential variation in sensitivity among members of the human population

C. Exposure Assessment

    1. Dietary exposure from food and feed uses. In evaluating dietary 
exposure to dimethenamid-P and/or dimethenamid, EPA considered exposure 
under the petitioned-for tolerances as well as all existing 
dimethenamid tolerances in 40 CFR 180.464 which are established for 
either of the herbicides dimethenamid-P (an enriched S-isomer with 
90:10 mixture of the S- and R-isomers) or dimethenamid (a 50:50 racemic 
mixture of the S- and R-isomers). Therefore, EPA assessed dietary 
exposures from dimethenamid-P and/or dimethenamid 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. Such effects were identified 
for dimethenamid and dimethenamid-P. In estimating acute dietary 
exposure, EPA used food consumption information from the United States 
Department of Agriculture (USDA) 2003-2008 Nationwide Continuing 
Surveys of Food Intake by Individuals (CSFII). The acute dietary 
analysis was conducted for dimethenamid and/or dimethenamid-P assuming 
tolerance level residues, default processing factors, and 100% crop 
treated (CT) information.
    ii. Chronic exposure. In conducting the chronic dietary exposure 
assessment EPA used the food consumption data from the USDA 2003-2008 
CSFII. The chronic dietary exposure assessment was conducted for 
dimethenamid and/or dimethenamid-P assuming tolerance level residues, 
default processing factors, and 100% CT information.
    iii. Cancer. As discussed in Unit III.A, EPA has concluded that 
cancer dietary risk concerns due to long-term consumption of 
dimethenamid residues are adequately addressed by the chronic dietary 
exposure analysis using the reference dose; therefore, a separate 
cancer dietary exposure analysis was not performed.
    iv. Anticipated residue and percent crop treated (PCT) information. 
Tolerance level residues and 100% CT were assumed for all food 
    2. Dietary exposure from drinking water. The Agency used screening 
level water exposure models in the dietary exposure analysis and risk 
assessment for dimethenamid-P and/or dimethenamid in drinking water. 
These simulation models take into account data on the physical, 
chemical, and fate/transport characteristics of dimethenamid-P and/or 
dimethenamid. 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 Surface Water Concentration Calculator (SWCC) and the 
Pesticide Root Zone Model for Ground Water (PRZM-GW), estimated 
drinking water concentrations (EDWCs) were calculated for the parent 
compound plus its ethanesulfonic acid and oxanilic acid degradates, 
which are residues of concern in drinking water as follows: For acute 
exposures, EDWCs are estimated to be 73 parts per billion (ppb) for 
surface water and 153 ppb for ground water; for chronic exposures, 
EDWCs for non-cancer assessments are estimated to be 27 ppb for surface 
water and 140 ppb for ground water.
    Modeled estimates of drinking water concentrations were directly 
entered into the dietary exposure model.

[[Page 9213]]

    Because there was little difference between the maximum EDWCs for 
acute and chronic exposures, the maximum water concentration value of 
153 ppb was used to assess the contribution to drinking water for both 
the acute and chronic dietary risk assessments.
    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). Although there are no 
currently registered uses of dimethenamid that could result in 
residential exposures, dimethenamid-P is currently registered for the 
following uses that could result in residential exposures: Turf grass, 
ornamentals, and tree plantations. Only short-term residential 
exposures to dimethenamid-P are expected based on the 2012 Residential 
Standard Operating Procedures (SOPs). Potential exposure/risk scenarios 
identified for residential handlers include:
     Mixing/loading/applying liquid formulations to lawns/turf 
with a hose-end and/or backpack sprayer, and a manually-pressurized 
hand wand.
     Mixing/loading/applying liquid formulations to garden/
trees with a sprinkler can and a hose-end sprayer.
     Mixing/loading/applying granular formulations to lawns/
turf with a push-type rotary sprayer and a belly grinder.
     Mixing/loading/applying granular formulations to garden/
trees with a shaker can/cup, a spoon or by hand dispersal.
    The scenarios, routes of exposure, and lifestages of potential 
post-application exposure include:
     Physical activities on turf: Adults (dermal) and children 
1 to <2 years old (dermal and incidental oral).
     Mowing: Adults (dermal) and children 11 to <16 years old 
     Golfing: Adults (dermal), children 11 to <16 years old 
(dermal), and children 6 to <11 years old (dermal).
     Contact with Treated Gardens and Trees: Adults (dermal) 
and children 6 to <11 years old (dermal). The values used for aggregate 
assessment are based on the worst-case residential exposure estimates 
via the inhalation (adult male) and oral (child 1 < 2 years old) 
    Further information regarding EPA standard assumptions and generic 
inputs for residential exposures may be found at http://www.epa.gov/pesticides/trac/science/trac6a05.pdf.
    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.''
    EPA has not found that dimethenamid-P and dimethenamid share a 
common mechanism of toxicity with any other substances, or that they 
appear to produce a toxic metabolite produced by other substances. For 
the purposes of this tolerance action, therefore, EPA has assumed that 
dimethenamid-P and dimethenamid do not have 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 EPA's Web site 
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 Food Quality 
Protection Act Safety Factor (FQPA 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. There is no concern for 
increased qualitative and/or quantitative susceptibility following in 
utero (rats and rabbits) and pre-and post-natal exposure (rats). The 
NOAEL and LOAEL values for the fetal/pup effects observed in the 
developmental study and effects seen in the reproduction studies 
occurred at the same doses or higher than those which caused maternal 
toxicity. The rabbit developmental study was used as an acute dietary 
endpoint for females 13-49 years of age. The POD selected for risk 
assessment are protective of effects seen in these guideline studies. 
Therefore, the acute and chronic dietary risk assessments are 
protective of potential fetal/offspring effects.
    3. Conclusion. EPA has determined that reliable data show that it 
would be safe for infants and children to reduce the FQPA SF to 1X. 
That decision is based on the following findings:
    i. The toxicity database for dimethenamid and dimethenamid-P is 
    ii. There is no indication that dimethenamid or dimethenamid-P 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 dimethenamid or dimethenamid-P 
results in increased susceptibility in utero in rat or rabbit prenatal 
developmental studies or in young rats in the 2-generation reproduction 
    iv. There are no residual uncertainties identified in the exposure 
databases. The dietary food exposure assessments were performed based 
on 100% CT and tolerance-level residues which results in very high-end 
estimates of dietary exposure. The dietary drinking water assessment, 
which included parent plus its ethanesulfonic acid and oxanilic acid 
degradates, utilizes values generated by model and associated modeling 
parameters which are designed to provide health protective, high-end 
estimates of water concentrations. These assessments will not 
underestimate the exposure and risks posed by dimethenamid-P and/or 
dimethenamid residues of concern.

E. Aggregate Risks and Determination of Safety

    EPA determines whether acute and chronic dietary pesticide 
exposures are safe by comparing aggregate exposure estimates to the 
acute PAD (aPAD) and chronic PAD (cPAD). For linear cancer risks, EPA 
calculates the lifetime probability of acquiring cancer 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 appropriate PODs to ensure that an 
adequate MOE exists.
    1. Acute risk. Using the exposure assumptions discussed in this 
unit for acute exposure, the acute dietary exposure from food and water 
to dimethenamid-P and/or dimethenamid residues of concern will occupy 
1.3% of the aPAD for infants <1 year of age, the population group 
receiving the greatest exposure.
    2. Chronic risk. Using the exposure assumptions described in this 
unit for chronic exposure, EPA has concluded that chronic exposure to 
dimethenamid-P and dimethenamid residues of concern from food and water 
will utilize 17% of the cPAD for infants <1 year of

[[Page 9214]]

age, the population group receiving the greatest exposure.
    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). Dimethenamid-
P 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 dimethenamid-P.
    Dermal and inhalation exposures to handlers were not aggregated 
because the toxicity endpoints for these exposure routes are not based 
on common toxicity effects in/of the liver. Dermal effects (bw gain) 
were considered to be non-specific. EPA aggregated the worst-case 
residential exposure estimates via the inhalation (adult male) and oral 
(child 1 < 2 years old) routes.
    Using the exposure assumptions described in this unit for short-
term exposures, EPA has concluded the combined short-term food, water, 
and residential exposures result in an aggregate MOEs of 2,200 for 
adults and 1,100 for children 1-2 years old. Because EPA's LOC for 
dimethenamid-P is a MOE of 100 or below, these MOEs are not of concern.
    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). An intermediate-term adverse effect was identified; however, 
dimethenamid-P is not registered for any use patterns that would result 
in intermediate-term residential exposure. Intermediate-term risk is 
assessed based on intermediate-term residential exposure plus chronic 
dietary exposure. Because there is no intermediate-term residential 
exposure and chronic dietary exposure has already been assessed under 
the appropriately protective cPAD (which is at least as protective as 
the POD used to assess intermediate-term risk), no further assessment 
of intermediate-term risk is necessary, and EPA relies on the chronic 
dietary risk assessment for evaluating intermediate-term risk for 
    5. Aggregate cancer risk for U.S. population. As indicated in Unit 
III.A., EPA has concluded that the chronic RfD would be protective of 
any cancer effects. Based on the results of the chronic aggregate risk 
assessment, EPA concludes there is no risk of concern for cancer 
effects from exposure to dimethenamid and dimethenamid-P.
    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 dimethenamid and dimethenamid-P residues of concern.

IV. Other Considerations

A. Analytical Enforcement Methodology

    An adequate enforcement method is available for determining 
residues of dimethenamid in plant commodities. The Gas Chromatography/
Nitrogen-Phosphorus Detector (GC/NPD) method (AM-0884-0193-1) has been 
validated by the Agency and submitted for publication in the Food and 
Drug Administration (FDA) Pesticide Analytical Manual (PAM), Volume II. 
The limit of quantitation (LOQ; determined as the lowest level of 
method validation, LLMV) is 0.01 ppm. This method is not enantiomer 

B. International Residue Limits

    In making its tolerance decisions, EPA seeks to harmonize U.S. 
tolerances with international standards whenever possible, consistent 
with U.S. food safety standards and agricultural practices. EPA 
considers the international maximum residue limits (MRLs) established 
by the Codex Alimentarius Commission (Codex), as required by FFDCA 
section 408(b)(4). The Codex Alimentarius is a joint United Nations 
Food and Agriculture Organization/World Health Organization food 
standards program, and it is recognized as an international food safety 
standards-setting organization in trade agreements to which the United 
States is a party. EPA may establish a tolerance that is different from 
a Codex MRL; however, FFDCA section 408(b)(4) requires that EPA explain 
the reasons for departing from the Codex level.
    The Codex has not established a MRL for dimethenamid or 
dimethenamid-P in/on members of cottonseed subgroup 20C and cotton, gin 

C. Revisions to Petitioned-For Tolerances

    A separate tolerance in cotton, seed, refined oil is not needed 
since the exaggerated rate processing study demonstrates that the 
petitioned-for tolerance in/on cottonseed subgroup 20C (0.01 ppm) will 
be adequate to cover potential residues of dimethenamid in refined oil.

 V. Conclusion

    Therefore, tolerances are established for residues of the herbicide 
dimethenamid, 1(RS)-2-chloro-N-[(1-methyl-2-methoxy) ethyl]-N-(2, 4-
dimethylthien-3-yl) acetamide, applied as either the 90:10 or 50:50 S:R 
isomers, in or on cottonseed subgroup 20C at 0.01 ppm and cotton, gin 
byproducts at 1.5 ppm.

VI. Statutory and Executive Order Reviews

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

[[Page 9215]]

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) (2 U.S.C. 1501 et seq.).
    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) (15 U.S.C. 272 note).

VII. Congressional Review Act

    Pursuant to the Congressional Review Act (5 U.S.C. 801 et seq.), 
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 
the rule in the Federal Register. This action 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: February 10, 2015.
Susan Lewis,
Director, Registration Division, Office of Pesticide Programs.

    Therefore, 40 CFR chapter I is amended as follows:


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

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

2. In Sec.  180.464, add alphabetically the following commodities to 
the table in paragraph (a) to read as follows:

Sec.  180.464  Dimethenamid; tolerances for residues.

    (a) * * *

                                                             Parts per
                        Commodity                             million
                                * * * * *
Cotton, gin byproducts..................................             1.5
Cottonseed subgroup 20C.................................            0.01
                                * * * * *

* * * * *
[FR Doc. 2015-03458 Filed 2-19-15; 8:45 am]