Document ID: EPA-HQ-OPP-2016-0171-0004
Agency: epa
Document Type: Rule
Title: Pesticide Tolerances: Pyroxasulfone
Posted Date: 2017-04-18T04:00Z

[Federal Register Volume 82, Number 73 (Tuesday, April 18, 2017)]
[Rules and Regulations]
[Pages 18230-18235]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-07819]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[EPA-HQ-OPP-2016-0171; FRL-9959-25]

Pyroxasulfone; Pesticide Tolerances

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This regulation establishes tolerances for residues of 
pyroxasulfone in or on multiple commodities which are identified and 
discussed later in this document. Interregional Research Project Number 
4 (IR-4) and K-I Chemical requested these tolerances under the Federal 
Food, Drug, and Cosmetic Act (FFDCA).

DATES: This regulation is effective April 18, 2017. Objections and 
requests for hearings must be received on or before June 19, 2017, 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-2016-0171, 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: Michael Goodis, 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.

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. 
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 
Printing Office's e-CFR site at http://www.ecfr.gov/cgi-bin/text-idx?&c=ecfr&tpl=/ecfrbrowse/Title40/40tab_02.tpl.

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-2016-0171 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 
June 19, 2017. 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-2016-0171, 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 
20460-0001.
     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 Tolerances

    In the Federal Register of May 19, 2016 (81 FR 31581) (FRL-9946-
02), EPA issued a document pursuant to FFDCA section 408(d)(3), 21 
U.S.C.

[[Page 18231]]

346a(d)(3), announcing the filing of a pesticide petition (PP 6E8454) 
by IR-4, Rutgers University, 500 College Rd. East, Suite 201 W, 
Princeton, NJ 08540. The petition requested that 40 CFR part 180 be 
amended by establishing tolerances for residues of pyroxasulfone (3-
[[[5-(difluoromethoxy)-1-methyl-3-(trifluoromethyl)-1H-pyrazol-4-
yl]methyl]sulfonyl]-4,5-dihydro-5,5-dimethylisoxazole) and its 
metabolites (5-(difluoromethoxy)-1-methyl-3-(trifluoromethyl)-1H-
pyrazol-4- carboxylic acid (M-3); 5-(difluoromethoxy)-3-
(trifluoromethyl)-1H-pyrazol-4-yl]methanesulfonic acid (M-25); 3-[1-
carboxy-2-(5,5-dimethyl-4,5-dihydroisoxazol-3-ylthio)ethylamino]-3-
oxopropanoic acid (M-28); and 5-(difluoromethoxy)-1-methyl-3-
(trifluoromethyl)-1H-pyrazol-4-yl]methanesulfonic acid (M-1)) 
calculated as the stoichiometric equivalent of pyroxasulfone in or on 
the raw agricultural commodity sunflower subgroup 20B at 0.2 parts per 
million. That document referenced a summary of the petition prepared by 
K-I Chemical U.S.A. Inc., the registrant, which is available in the 
docket, http://www.regulations.gov. A comment supporting IR-4's 
petition requesting this tolerance was received in response to the 
notice of filing.
    In the Federal Register of December 20, 2016 (81 FR 92758) (FRL-
9956-04), 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 
5F8417) by K-I Chemical USA. Inc., 11 Martine Ave., Suite 970, White 
Plains, NY 10606. The petition requested that 40 CFR part 180 be 
amended by establishing tolerances for residues of the herbicide, 
pyroxasulfone (3-[(5-(difluoromethoxy)-1-methyl-3-(trifluoromethyl) 
pyrazole-4-ylmethylsulfonyl]-4,5-dihydro-5,5-dimethyl-1,2-oxazole) and 
its metabolites in or on dried shelled peas and beans (crop subgroup 
6C) at 0.15 ppm, pea hay at 0.40 ppm, pea vines at 0.20 ppm, cowpea hay 
at 0.07 ppm, cowpea forage at 3.0 ppm, flax at 0.07 ppm, peanut at 0.20 
ppm, peanut hay at 3.0 ppm, peanut meal at 0.40 ppm, and vegetable, 
foliage of legume, except soybean, subgroup 7A at 3.0 ppm. That 
document referenced a summary of the petition prepared by K-I Chemical 
U.S.A. Inc., the registrant, which is available in docket number EPA-
HQ-OPP-2015-0787, http://www.regulations.gov.
    The December 20, 2016 notice of filing supersedes a notice of 
filing published in the Federal Register of June 22, 2016 (81 FR 40594) 
(FRL-9947-32), which was based on an earlier version of the same 
petition (5F8417). Following that June 2016 publication, K-1 amended 
its petition to include additional crops and adjust the tolerance 
levels requested. The December 20, 2016 document provided notice of 
that updated petition. Although no comments were received in response 
to the December 20, 2016 notice of filing, one comment was received in 
response to the June 22, 2016 notice. EPA is carrying that earlier 
comment forward as a comment on the petition noticed in December 2016 
and provides a response to that comment in Unit IV.C.
    Based upon review of the data supporting the petition, EPA has 
modified the levels at which some of the tolerances are being 
established and also modified some of the crop definitions. The reasons 
for these changes are explained in Unit IV.D.

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 pyroxasulfone including 
exposure resulting from the tolerances established by this action. 
EPA's assessment of exposures and risks associated with pyroxasulfone 
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.
    Subchronic and chronic toxicity testing of pyroxasulfone in mice, 
rats and dogs produced a variety of adverse effects in several target 
organs, but the most sensitive effect is neurotoxicity in dogs. Effects 
seen in animal studies ranged from cardiac toxicity (increased 
cardiomyopathy in mice and rats), liver toxicity (centrilobular 
hepatocellular hypertrophy, histopathological and/or clinical 
pathological indicators), neurotoxicity characterized by axonal/myelin 
degeneration in the sciatic nerve (dog, mouse and rat) and spinal cord 
sections (dog), skeletal muscle myopathy, kidney toxicity (increased 
incidence of chronic progressive nephropathy in dogs and retrograde 
nephropathy in mice), urinary bladder mucosal hyperplasia, 
inflammation, and urinary bladder transitional cell papillomas (rats). 
Decreased body weight and enzyme changes were noted in some studies. 
Toxic adverse effects (impaired hind limb function, ataxia, hind limb 
twitching and tremors; increased creatine kinase, aspartate 
aminotransferase; axonal/myelin degeneration of the sciatic nerve and 
spinal cord sections) in dogs occurred at >=10 mg/kg/day doses while in 
the mouse toxic adverse effects (degeneration of sciatic and trigeminal 
nerve axons and their associated myelin sheaths and chronic progressive 
nephropathy, renal tubular adenomas) occurred at higher doses (131 mg/
kg/day and above).
    Comparing effects by route of administration, pyroxasulfone was 
moderately toxic to rats following a 4-week dermal exposure producing 
local inflammation and systemic effects of minimal to mild cardiac 
myofiber degeneration at the limit dose of 1,000 mg/kg/day with a NOAEL 
of 100 mg/kg/day. No adverse effects were noted in an inhalation study 
following exposure for 28 days at 200 mg/m\3\/day (equivalent to 52.2 
mg/kg/day oral dose), the highest dose tested of an aerosol dust.
    In cancer studies in mice and rats, renal tubular adenomas were 
observed in male mice at a dietary dose of 0.6 and 255 mg/kg/day (but 
not at an intermediate dose of 18 mg/kg/day) and urinary bladder 
transitional cell papillomas were observed in male rats at 42 and 84 
mg/kg/day. Based on available information, the Agency concluded that 
the kidney adenomas in male mice were not treatment-related.

[[Page 18232]]

The Agency considered the transitional cell bladder tumors in male rats 
to be treatment-related based on statistically significant trends for 
urinary bladder transitional cell papillomas and combined papillomas 
and carcinomas, the occurrence of preneoplastic lesions at 42 and 84 
mg/kg/day and the rare occurrence of bladder transitional cell tumors. 
The Agency concluded that the mode of action for bladder tumors has 
been adequately established based on submitted data that support both a 
dose-response and temporal concordance of the key events and bladder 
tumors. The available data indicate that the formation of urinary 
bladder calculi is the prerequisite for subsequent hyperplasia and 
neoplasia and that tumors do not develop at doses too low to produce 
calculi. The Agency has determined that the quantification of risk 
using a non-linear approach (i.e., RfD) will adequately account for all 
chronic toxicity, including carcinogenicity, that could result from 
exposure to pyroxasulfone. There is a clear threshold of 1,000 ppm 
(42.55 mg/kg/day) for tumorigenesis. A point of departure (POD) of 50 
ppm (2.0 mg/kg/day) is not expected to result in urinary bladder 
calculi formation which is a prerequisite for subsequent hyperplasia 
and neoplasia.
    Pyroxasulfone did not exhibit developmental toxicity in the rat 
developmental toxicity study at the limit dose of 1,000 mg/kg/day and 
it exhibited slight developmental toxicity in rabbits (reduced fetal 
weight and resorptions) at the limit dose of 1,000 mg/kg/day. However, 
developmental effects were noted in post-natal day (PND) 21 offspring 
at 300 mg/kg/day in the rat developmental neurotoxicity (DNT) study 
characterized as decreased brain weight and morphometric changes. 
Developmental effects in the rabbit developmental study and DNT study 
occurred in the absence of maternal toxicity, indicating potential 
increased quantitative susceptibility of offspring. In a reproductive 
toxicity in rats reduced pup weight and body weight gains during 
lactation occurred at similar doses causing pronounced maternal 
toxicity (reduced body weight, body weight gain and food consumption 
and increased kidney weight, cardiomyopathy and urinary bladder mucosal 
hyperplasia with inflammation).
    Pyroxasulfone did not produce immunotoxic effects in mice following 
dietary feeding for 28 days up to 4,000 ppm (633/791 mg/kg/day, M/F) or 
in rats at dietary concentrations of 7,500 ppm (529/570 mg/kg/day in M/
F).
    Specific information on the studies received and the nature of the 
adverse effects caused by pyroxasulfone 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.regulations.gov in the document title ``Pyroxasulfone Human Health 
Risk Assessment for the Section 3 New Uses of Pyroxasulfone on Crop 
Subgroup 6C, Sunflower Subgroup 20B, Flax, and Peanut'' on page 44 in 
docket ID number EPA-HQ-OPP-2016-0171.

B. Toxicological Points of Departure/Levels of Concern

    Once a pesticide's toxicological profile is determined, EPA 
identifies toxicological points of departure (POD) and levels of 
concern 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 no adverse effects are observed (the NOAEL) 
and the lowest dose at which adverse effects of concern are identified 
(the LOAEL). 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://www2.epa.gov/pesticide-science-and-assessing-pesticide-risks/assessing-human-health-risk-pesticides.
    A summary of the toxicological endpoints for pyroxasulfone used for 
human risk assessment is shown in Table 1 of this unit.

 Table 1--Summary of Toxicological Doses and Endpoints for Pyroxasulfone for Use in Human Health Risk Assessment
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                                    Point of departure
        Exposure/scenario            and uncertainty/     RfD, PAD, LOC for     Study and toxicological effects
                                      safety factors       risk assessment
----------------------------------------------------------------------------------------------------------------
Acute dietary (General population  NOAEL = 100 mg/kg/    Acute RfD = 1.0 mg/  Developmental neurotoxicity study
 including infants and children).   day.                  kg/day.              (DNT) in rats.
                                   UFA = 10x...........  aPAD = 1.0 mg/kg/    The LOAEL of 300 mg/kg/day is
                                   UFH = 10x...........   day.                 based on decreased brain weight
                                   FQPA SF = 1x........                        in both sexes, reduced thickness
                                                                               of the hippocampus, corpus
                                                                               callosum and cerebellum in PND 21
                                                                               female offspring.
----------------------------------------------------------------------------------------------------------------
Chronic dietary (All populations)  NOAEL = 2 mg/kg/day.  Chronic RfD = 0.02   One- year chronic dog study.
                                   UFA = 10x...........   mg/kg/day.          The LOAEL of 10 mg/kg/day is based
                                   UFH = 10x...........  cPAD = 0.02 mg/kg/    on impaired hind limb function,
                                   FQPA SF = 1x........   day.                 ataxia, hind limb twitching and
                                                                               tremors; clinical pathology:
                                                                               Increased creatine kinase,
                                                                               aspartate aminotransferase;
                                                                               axonal/myelin degeneration of the
                                                                               sciatic nerve and spinal cord
                                                                               sections.
                                  ------------------------------------------------------------------------------
Cancer (Oral, dermal, inhalation)      ``Not Likely to be Carcinogenic to Humans'' at doses that do not cause
                                     crystals with subsequent calculi formation resulting in cellular damage of
                                        the urinary tract. Risk is quantified using a non-linear (i.e., RfD)
                                                                      approach.
----------------------------------------------------------------------------------------------------------------
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. UF = uncertainty factor.
  UFA = extrapolation from animal to human (interspecies). UFH = potential variation in sensitivity among
  members of the human population (intraspecies).

[[Page 18233]]

C. Exposure Assessment

    1. Dietary exposure from food and feed uses. In evaluating dietary 
exposure to pyroxasulfone, EPA considered exposure under the 
petitioned-for tolerances as well as all existing pyroxasulfone 
tolerances in 40 CFR 180.659. EPA assessed dietary exposures from 
pyroxasulfone 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 pyroxasulfone. In estimating acute 
dietary exposure, EPA used food consumption information from the United 
States Department of Agriculture's (USDA) 2003-2008 National Health and 
Nutrition Survey/What We Eat in America (NHANES/WWEIA). As to residue 
levels in food, EPA assumed 100 percent crop treated (PCT) and 
tolerance level residues adjusted for metabolites which are not in the 
tolerance expression.
    ii. Chronic exposure. In conducting the chronic dietary exposure 
assessment EPA used the food consumption data from USDA's 2003-2008 
NHANES/WWEIA. As to residue levels in food, EPA assumed 100 PCT and 
tolerance level residues adjusted for metabolites which are not in the 
tolerance expression.
    iii. Cancer. Based on the data summarized in Unit III.A., EPA has 
concluded that a nonlinear RfD approach is appropriate for assessing 
cancer risk to pyroxasulfone. Cancer risk was assessed using the same 
exposure estimates as discussed in Unit III.C.1.ii., chronic exposure.
    iv. Anticipated residue and percent crop treated (PCT) information. 
EPA did not use anticipated residue or PCT information in the dietary 
assessment for pyroxasulfone. Tolerance level residues and 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 pyroxasulfone in drinking water. These simulation models 
take into account data on the physical, chemical, and fate/transport 
characteristics of pyroxasulfone. Further information regarding EPA 
drinking water models used in pesticide exposure assessment can be 
found at http://www2.epa.gov/pesticide-science-and-assessing-pesticide-risks/about-water-exposure-models-used-pesticide.
    Based on the Pesticide Root Zone Model/Exposure Analysis Modeling 
System (PRZM/EXAMS) and Pesticide Root Zone Model Ground Water (PRZM 
GW), the estimated drinking water concentrations (EDWCs) of 
pyroxasulfone for acute exposures are estimated to be 16.7 parts per 
billion (ppb) for surface water and 210 ppb for ground water. EDWCs of 
pyroxasulfone for chronic exposures for non-cancer assessments are 
estimated to be 4.5 ppb for surface water and 174 ppb for ground water.
    Modeled estimates of drinking water concentrations were directly 
entered into the dietary exposure model. For the acute dietary risk 
assessment, the water concentration value of 210 ppb was used to assess 
the contribution to drinking water. For the chronic dietary risk 
assessment, the water concentration value of 174 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).
    Pyroxasulfone is not registered for any specific use patterns that 
would result in residential exposure.
    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 pyroxasulfone to share a common mechanism of 
toxicity with any other substances, and pyroxasulfone does not appear 
to produce a toxic metabolite produced by other substances. For the 
purposes of this tolerance action, therefore, EPA has assumed that 
pyroxasulfone does 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://www2.epa.gov/pesticide-science-and-assessing-pesticide-risks/cumulative-assessment-risk-pesticides.

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. Pyroxasulfone did not 
exhibit developmental toxicity in the rat guideline study at the limit 
dose of 1,000 mg/kg/day and it exhibited slight developmental toxicity 
in rabbits (reduced fetal weight and resorptions) at the limit dose of 
1,000 mg/kg/day. However, developmental effects were noted in PND 21 
offspring at 300 mg/kg/day in the rat developmental neurotoxicity (DNT) 
study characterized as decreased brain weight and morphometric changes. 
Developmental effects in the rabbit developmental study and DNT study 
occurred in the absence of maternal toxicity, indicating potential 
increased quantitative susceptibility of offspring. In a rat 
reproductive toxicity study, reduced pup weight and body weight gains 
during lactation occurred at similar doses causing pronounced maternal 
toxicity (reduced body weight, body weight gain and food consumption 
and increased kidney weight, cardiomyopathy and urinary bladder mucosal 
hyperplasia with inflammation).
    3. Conclusion. EPA has determined that reliable data show the 
safety of infants and children would be adequately protected if the 
FQPA SF were reduced to 1x. That decision is based on the following 
findings:
    i. The toxicity database for pyroxasulfone is complete.
    ii. Available data indicates that pyroxasulfone produces neurotoxic 
effects in rats. The toxicity database includes specific acute and 
subchronic neurotoxicity tests, as well as a developmental 
neurotoxicity study (DNT). Although the DNT indicated offspring are 
more sensitive to neurotoxic effects of pyroxasulfone, the dose-
response is well characterized for neurotoxicity and a NOAEL is

[[Page 18234]]

identified; therefore, there is no residual uncertainty with regard to 
neurotoxic effects for which a 10X must be retained.
    iii. As discussed in Unit III.D.2., there is evidence of increased 
quantitative susceptibility of fetuses and offspring following in utero 
or post-natal exposure to pyroxasulfone (based on a DNT study in rats 
and a developmental study in rabbits). In rabbits, developmental 
toxicity was only seen at the limit dose of 1000 mg/kg/day as reduced 
fetal weight and increased fetal resorptions with a NOAEL of 500 mg/kg/
day for these effects, compared to no maternal toxicity at these doses. 
In a DNT study in rats, offspring toxicity was seen at 300 mg/kg/day 
compared to no maternal toxicity at 900 mg/kg/day. Notwithstanding, the 
Agency concludes that there is no residual uncertainty concerning these 
effects. The available studies show clear NOAELs and LOAELs for these 
effects, which are occurring only at doses much higher than the 
endpoints on which the Agency is regulating.
    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. EPA made conservative 
(protective) assumptions in the ground and surface water modeling used 
to assess exposure to pyroxasulfone in drinking water. These 
assessments will not underestimate the exposure and risks posed by 
pyroxasulfone.

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 pyroxasulfone will occupy 3.7% of the aPAD for all infants less than 
1-year-old, 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 
pyroxasulfone from food and water will utilize 49% of the cPAD for all 
infants less than 1-year-old, the population group receiving the 
greatest exposure. There are no residential uses for pyroxasulfone.
    3. Short- and intermediate-term risk. Short- and intermediate-term 
aggregate exposure takes into account short-term residential exposure 
plus chronic exposure to food and water (considered to be a background 
exposure level).
    Short- and intermediate-term adverse effects were identified; 
however, pyroxasulfone is not registered for any use patterns that 
would result in short- or intermediate-term residential exposure. 
Short- and intermediate-term risk is assessed based on short- and 
intermediate-term residential exposure plus chronic dietary exposure. 
Because there is no short- or 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 short-term risk), no further assessment of short- or 
intermediate-term risk is necessary, and EPA relies on the chronic 
dietary risk assessment for evaluating short- and intermediate-term 
risk for pyroxasulfone.
    4. Aggregate cancer risk for U.S. population. As explained in Unit 
III.A., the Agency has determined that the quantification of risk using 
a non-linear (i.e., RfD) approach will adequately account for all 
chronic toxicity, including carcinogenicity, that could result from 
exposure to pyroxasulfone. Therefore, based on the results of the 
chronic risk assessment discussed in Unit III.E.2., pyroxasulfone is 
not expected to pose a cancer risk to humans.
    5. 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 pyroxasulfone residues.

IV. Other Considerations

A. Analytical Enforcement Methodology

    Adequate enforcement methodology (high performance liquid 
chromatography/triple quadrupole 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; email address: 
residuemethods@epa.gov.

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 any MRLs for residues of 
pyroxasulfone in or on any of the commodities in this document.

C. Response to Comments

    One comment was received in response to the June 22, 2016 Notice of 
Filing (81 FR 40594) (FRL-9947-32). The comment stated in part that 
most Americans ``don't need or want more toxic chemicals'' and that EPA 
should deny this submission. The Agency recognizes that some 
individuals believe that pesticides should be banned on agricultural 
crops. However, the existing legal framework provided by section 408 of 
the FFDCA states that tolerances may be set when persons seeking such 
tolerances or exemptions have demonstrated that the pesticide meets the 
safety standard imposed by that statute. The citizen's comment does not 
provide any information upon which the Agency could base a decision 
deny the petition.

D. Revisions to Petitioned-For Tolerances

    The sunflower subgroup 20B tolerance is being established at 0.30 
ppm instead of the proposed level of 0.2 ppm. This is because the 
petitioner did not convert the metabolites to parent equivalents and 
when those total residues are put into the tolerance calculator the 
correct value is 0.30 ppm. Also, based on the Agency's review of the 
residue data, the tolerances for peanut and peanut hay are being 
established at 0.30 ppm and 4.0 ppm, respectively. In addition, 
separate tolerances are not being established on field pea hay and 
vines and cowpea hay

[[Page 18235]]

and forage because they will be covered by the tolerance being 
established on ``vegetable, foliage of legume, except soybean, subgroup 
7A.''

V. Conclusion

    Therefore, tolerances are established for residues of 
pyroxasulfone, including its metabolites and degradates, in or on: 
Flax, seed at 0.07 ppm; pea and bean, dried shelled, except soybean, 
subgroup 6C at 0.15 ppm; peanut at 0.30 ppm; peanut, hay at 4.0 ppm; 
peanut, meal at 0.40 ppm; sunflower subgroup 20B at 0.30 ppm; and 
vegetable, foliage of legume, except soybean, subgroup 7A at 3.0 ppm.

VI. Statutory and Executive Order Reviews

    This action 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 action has been 
exempted from review under Executive Order 12866, this action 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 action 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 action 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 
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 action. In addition, this 
action does not impose any enforceable duty or contain any unfunded 
mandate as described under Title II of the Unfunded Mandates Reform Act 
(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 (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 24, 2017,
Meredith F. Laws,
Acting Director, Registration Division, Office of Pesticide Programs.
    Therefore, 40 CFR part 180 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. In Sec.  180.659, add paragraph (a)(5) to read as follows:

Sec.  180.659  Pyroxasulfone; tolerances for residues.

    (a) * * *
    (5) Tolerances are established for residues of the herbicide 
pyroxasulfone, including its metabolites and degradates, in or on the 
commodities in the table below. Compliance with the tolerance levels 
specified below is to be determined by measuring only the sum of 
pyroxasulfone (3-[(5-difluoromethoxy-1-methyl-3-
(trifluoromethyl)pyrazol-4-ylmethylsulfonyl]-4,5-dihydro-5,5-dimethyl-
1,2-oxazole), and its metabolites, M-1 (5-difluoromethoxy-1-methyl-3-
trifluoromethyl-1H-pyrazol-4-yl) methanesulfonic acid), M-3 (5-
difluoromethoxy-1-methyl-3-trifluoromethyl-1H-pyrazol-4-carboxylic 
acid), M-25 (5-difluoromethoxy-3-trifluoromethyl-1H-pyrazol-4-
yl)methanesulfonic acid) and M-28 (3-[1-carboxy-2-(5,5-dimethyl-4,5-
dihydroisoxazol-3-ylthio)ethylamino]-3-oxopropanoic acid) calculated as 
the stoichiometric equivalent of pyroxasulfone, in or on the following 
commodities:

------------------------------------------------------------------------
                                                              Parts per
                         Commodity                             million
------------------------------------------------------------------------
Flax, seed.................................................         0.07
Pea and bean, dried shelled, except soybean, subgroup 6C...         0.15
Peanut.....................................................         0.30
Peanut, hay................................................         4.0
Peanut, meal...............................................         0.40
Sunflower subgroup 20B.....................................         0.30
Vegetable, foliage of legume, except soybean, subgroup 7A..         3.0
------------------------------------------------------------------------

* * * * *
[FR Doc. 2017-07819 Filed 4-17-17; 8:45 am]
BILLING CODE 6560-50-P