Document ID: EPA-HQ-OPP-2011-1029-0003
Agency: epa
Document Type: Rule
Title: Exemptions from Requirements of Tolerances: 1,4-Dimethylnaphthalene; Amendment
Posted Date: 2012-11-16T05:00Z

[Federal Register Volume 77, Number 222 (Friday, November 16, 2012)]
[Rules and Regulations]
[Pages 68692-68697]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-27809]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[EPA-HQ-OPP-2011-1029; FRL-9368-2]

1,4-Dimethylnaphthalene; Amendment to an Exemption From the 
Requirement of a Tolerance

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This regulation amends the existing exemption from the 
requirement of a tolerance for residues of the plant growth regulator, 
1,4-dimethylnaphthalene (1,4-DMN) by expanding the current exemption to 
include all sprouting root and tuber vegetables (EPA Crop Group 01) and 
all bulb vegetables (EPA Crop Group 03). On behalf of D-I-1-4, Inc., a 
division of 1,4Group, Inc., Technology Sciences Group, Inc. (TSG) 
submitted a petition to EPA under the Federal Food, Drug, and Cosmetic 
Act (FFDCA), requesting that EPA amend the existing exemption from the 
requirement of a tolerance for 1,4-DMN. This regulation eliminates the 
need to establish a maximum permissible level for residues of 1,4-DMN 
under the FFDCA.

DATES: This regulation is effective November 16, 2012. Objections and 
requests for hearings must be received on or before January 15, 2013, 
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-2011-1029, 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), EPA West 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: Colin G. Walsh, Biopesticides and 
Pollution Prevention Division (7511P), Office of Pesticide Programs, 
Environmental Protection Agency, 1200 Pennsylvania Ave. NW., 
Washington, DC 20460-0001; telephone number: (703) 308-0298; email 
address: walsh.colin@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 40 CFR 
part 180 through the Government Printing Office's e-CFR site at http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?&c=ecfr&tpl=/ecfrbrowse/Title40/40tab_02.tpl.

To access the OCSPP test guidelines referenced in this document 
electronically, please go to http://www.epa.gov/ocspp and select ``Test 
Methods and Guidelines.''

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-2011-1029 in the subject line on

[[Page 68693]]

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 January 15, 2013. 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 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-2011-1029, 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 Confidential Business 
Information (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.htm.

Additional instructions on commenting or visiting the docket, along 
with more information about dockets generally, is available at http://www.epa.gov/dockets.

II. Background and Statutory Findings

    In the Federal Register of March 14, 2012 (77 FR 15012) (FRL-9335-
9), EPA issued a notice pursuant to FFDCA section 408(d)(3), 21 U.S.C. 
346a(d)(3), announcing the filing of a pesticide tolerance petition (PP 
1F7920) by TSG, Agent, 712 Fifth Street, Suite A, Davis, CA 95616, on 
behalf of D-I-1-4, Inc., a division of 1,4Group, Inc., P.O. Box 860, 
Meridian, ID 83680. The petition requested that 40 CFR 180.1142 be 
amended by expanding the current exemption to include all sprouting 
root, tuber, and bulb crops, thus establishing an exemption from the 
requirement of a tolerance for residues of the plant growth regulator, 
1,4-DMN, when applied postharvest to all sprouting root, tuber, and 
bulb crops in accordance with good agricultural practices. This notice 
referenced a summary of the petition prepared by the petitioner TSG, on 
behalf of D-I-1-4, Inc., a division of 1,4Group, Inc., which is 
available in the docket via http://www.regulations.gov. There were no 
comments received in response to the notice of filing.
    Section 408(c)(2)(A)(i) of FFDCA allows EPA to establish an 
exemption from the requirement for a tolerance (the legal limit for a 
pesticide chemical residue in or on a food) only if EPA determines that 
the exemption is ``safe.'' Section 408(c)(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. Pursuant to FFDCA section 408(c)(2)(B), in 
establishing or maintaining in effect an exemption from the requirement 
of a tolerance, EPA must take into account the factors set forth in 
FFDCA section 408(b)(2)(C), which require 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 * * 
*.'' Additionally, FFDCA section 408(b)(2)(D) requires that 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 performs a number of analyses to determine the risks from 
aggregate exposure to pesticide residues. First, EPA determines the 
toxicity of pesticides. Second, EPA examines exposure to the pesticide 
through food, drinking water, and through other exposures that occur as 
a result of pesticide use in residential settings.

III. Toxicological Profile

    Consistent with FFDCA section 408(b)(2)(D), EPA has reviewed the 
available scientific data and other relevant information in support of 
this action and considered its validity, completeness and reliability, 
and the relationship of this information 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.
    EPA established a tolerance exemption for 1,4-DMN in a Final Rule 
published in the Federal Register on February 8, 1995, (60 FR 7456-
7457) (FRL-4932-4), which supported the plant growth regulator 
postharvest use on potatoes. The toxicological data submitted to 
support the previous tolerance exemption included the following: Acute 
(six-pack) toxicity, three mutagenicity studies, and a report of no 
hypersensitivity incidents for 1,4-DMN. The mutagenicity studies 
included an Ames test, an in vitro test for unscheduled DNA synthesis, 
and an in vivo micronucleus assay. All of the studies/information 
submitted to support the previous tolerance exemption indicated a lack 
of toxicity hazards for mammals, and EPA concluded that there is a 
reasonable certainty of no harm to humans, including infants and 
children, from the proposed food uses of 1,4-DMN. This amendment 
proposes to expand the tolerance exemption when applied postharvest to 
all sprouting root, tuber, and bulb crops in accordance with good 
agricultural practices. In support of this expansion of the tolerance 
exemption, new data have been generated by the petitioner and reviewed 
by EPA to address the developmental toxicity (OCSPP Guideline No. 
870.3700) data requirement (the study was not submitted for the 
previous tolerance exemption). In addition, the petitioner submitted 
the following studies that were not required by EPA for this expansion 
of the tolerance exemption: In vivo unscheduled DNA synthesis, in vitro 
skin absorption, dermal sensitization, one-generation reproductive 
toxicity, and a combined chronic toxicity/carcinogenicity (OCSPP 
Guideline Nos. 870.5550, 870.7600, 870.2600, 870.3800, and 870.4300, 
respectively). The developmental data are required when the use of the 
substance under widespread and commonly recognized practices may 
reasonably be expected to result in significant exposure to humans, 
specifically females of child-bearing age. The rest of the 
toxicological profile as stated in the February 8, 1995 issue of the 
Federal Register, and referenced herein, has not changed. The data 
submitted for the previous tolerance exemption include the acute 
toxicity (six-pack) studies, three mutagenicity studies, and a report 
of no hypersensitivity incidents for 1,4-DMN. A copy of the February 8, 
1995 final rule document (60 FR 7456-7457) and risk assessments cited 
herein (Refs. 1 and 2) are located under docket ID number EPA-HQ-OPP-
2011-1029.
    As discussed in the Federal Register of February 8, 1995 (60 FR 
7456) and risk assessments (Refs. 1 and 2), 1,4-DMN is naturally 
occurring and has a nontoxic mode of action. 1,4-DMN is

[[Page 68694]]

found naturally occurring in potatoes (60 FR 7456) and detected in 
various other crops including cocoa, coffee, apples, corn, raisins, 
tomatoes, apricots, peaches, pear juice, eggplants, green peppers, star 
fruit, tea, radishes, oranges, cinnamon, poppies, and red beans (Ref. 
1). When conditions are right for sprouting, the potato metabolizes 
1,4-DMN to a low enough level so that sprouting can occur. 1,4-DMN is 
applied to postharvest sprouting root, tuber, and bulb stored crops at 
a level, generally 20 parts per million (ppm) up to 4 applications 
during a storage season, to continue to inhibit sprouting.
    As stated previously in this Unit, new toxicity data have been 
submitted in support of the request by the petitioner to expand the 
current tolerance exemption to cover all sprouting root, tuber, and 
bulb crops. These data include: (1) A prenatal developmental toxicity 
study and (2) additional data not required by EPA, but used to further 
support the developmental data and this expansion of the tolerance 
exemption. All new data, coupled with the data submitted to support the 
previous tolerance exemption (60 FR 7456), confirm the minimal human 
health hazard effects, as reported in the original assessment of the 
tolerance exemption, associated with dietary exposures of 1,4-DMN and 
fully demonstrate the lack of mammalian toxicity. Summaries of the new 
toxicological data submitted in support of the expansion of the 
tolerance exemption follow.

A. Developmental Toxicity

    A new developmental study (Master Record Identification (MRID) 
Number 48590905) was performed for 1,4-DMN to support the expansion of 
the tolerance exemption. 1,4-DMN was administered by oral gavage to 
female rabbits at the dose levels of 0, 25, 80, or 250 milligrams/per/
day (mg/kg/day) (23 rabbits per test group) over gestation days 6 
through 28. No treatment-related clinical signs were noted during the 
study, and gross necropsy findings were limited to those rabbits that 
underwent abortion (Ref. 1). The gross necropsy findings consisted of 
changes in the gastrointestinal tract (dilatation of stomach and/or 
intestines) and were likely related to the lack of eating prior to and 
during the abortion. Mean food consumption was significantly reduced in 
the 250 mg/kg/day treated doses shortly after treatment initiation 
(over gestation days 6 to 9 and 9 to 12). This reduction in food 
consumption was likely treatment-related. Corollary reductions in mean 
body weight gain were observed in the 250 mg/kg/day treated group over 
gestation days 6 to 9. Alterations in uterus weight were not observed, 
nor were changes seen in maternal body weight or body weight gain when 
corrected for uterus weight. As such, the changes seen early on in 
gestational body weight gain were considered to be solely associated 
with maternal toxicity. Therefore, the lowest observed adverse effect 
level (LOAEL) for maternal toxicity of 1,4-DMN in rats is 250 mg/kg/day 
based on reduced food consumption and reduced body weight gain. The no 
observed adverse effect level (NOAEL) for maternal toxicity is 80 mg/
kg/day based on no effects observed at this dose.
    For developmental toxicity, no treatment-related differences in 
litter viability were detected at any dose level tested. The number of 
male, female, and total fetuses (sexes combined) were similar across 
the treatment and control groups and average fetal weights were 
unaffected. No structural alterations, including gross external, 
visceral, skeletal, and cephalic, were evident from the fetal 
examinations; as such, 1,4-DMN did not produce any frank malformations 
and was not teratogenic. Based on no effects observed for developmental 
toxicity at any doses tested, the NOAEL for developmental toxicity is 
greater than 250 mg/kg/day (highest dose tested). The LOAEL was not 
identified for developmental toxicity, suggesting that the test animals 
could have tolerated a higher dose.
    Based on the developmental toxicity data submitted for this 
expansion to the tolerance exemption, which showed no adverse effects 
at the highest dose tested, 250 mg/kg/day, there are sufficient data 
and information to confirm that 1,4-DMN is not a developmental 
toxicant. Therefore, the consumption of food commodities that have been 
treated with 1,4-DMN when used as a pesticide is safe and will not 
result in any harm to human health, specifically women of child-bearing 
age, from dietary exposure.

B. Additional Toxicity Data

    Additional toxicity data for 1,4-DMN that were not required by EPA 
to support this expansion of the tolerance exemption were submitted by 
the petitioner. The additional data include the following: Unscheduled 
DNA synthesis (mutagenicity), in vitro skin absorption, dermal 
sensitization, one-generation reproductive toxicity, and a combined 
chronic toxicity/carcinogenicity study (OCSPP Guideline Nos. 870.5550, 
870.7600, 870.2600, 870.3800, and 870.4300, respectively). Although the 
developmental data submitted were sufficient to support this expansion 
of the tolerance exemption, EPA has used this data, along with the 
required data submitted to support the previous tolerance exemption (60 
FR 7456), to confirm that the consumption of food commodities that have 
been treated with 1,4-DMN when used as a pesticide is safe and will not 
result in any harm to human health from dietary exposure.
    1. An in vivo unscheduled DNA synthesis in rats (MRID 48590902) 
showed no genotoxicity activity in rat livers when given a single dose 
of 1,4-DMN up to the limit dose of 1,000 mg/kg (Ref. 1). These results, 
combined with the lack of mutagenic and genotoxic effects observed in 
the bacterial reverse mutation (Ames) test, in vitro unscheduled DNA 
synthesis in mammalian cells, and in vivo mammalian erythrocyte 
micronucleus test submitted to support the previous tolerance exemption 
(60 FR 7456), confirm that 1,4-DMN is not a mutagen.
    2. An in vitro precutaneous absorption test (MRID 48590903) in 
humans showed that the mean total dermal absorption of 1,4-DMN was 2.5% 
of the dose applied (Ref. 1). Based on the relatively low absorption of 
1,4-DMN and the data submitted to support the previous tolerance 
exemption (60 FR 7456), which included an acute dermal toxicity study 
that showed a low acute dermal toxicity (median lethal dose 
(LD)50 > 2,000 mg/kg), 1,4-DMN is not considered a dermal 
toxicant.
    3. A dermal sensitization test (MRID 48590904) utilizing the Local 
Lymph Node Assay (LLNA) method showed that 1,4-DMN is not a dermal 
sensitizer (Ref. 1). The dermal sensitization test utilizing the 
Buehler method submitted to support the previous tolerance exemption 
(60 FR 7456) also showed that 1,4-DMN is not a dermal sensitizer.
    4. A one-generation reproductive toxicity study (MRID 48590906) was 
conducted on rats to assess systemic, developmental, and reproductive 
toxicity. 1,4-DMN was administered in the diet at the dose 
concentrations of 0, 500, 2,000, and 7,500 ppm with each dose group 
consisting of 24 males and 24 female rats. The results of the study 
showed that the NOAEL for systemic toxicity was 2,000 ppm (equivalent 
to 121 to 207 mg/kg/day in parental male and female rats and 184 to 213 
mg/kg/day in F1 males and females, respectively) and the 
LOAEL was 7,500 ppm based on a single histological change in the kidney 
of one, 7,500 ppm treated rat (Ref. 1). The NOAEL and LOAEL for 
developmental toxicity were also 2,000 ppm and 7,500 ppm, respectively, 
based on delayed vaginal

[[Page 68695]]

patency and preputial separation in the 7,500 ppm group; although, the 
delay in development was considered secondary to body weight effects 
that were attributed to reduced food consumption. The NOAEL for 
reproductive toxicity was 7,500 ppm (equivalent to 441 to 591 mg/kg/day 
in parental male and female rats and 776 to 839 mg/kg/day in 
F1 males and females, respectively) based on the lack of 
change in reproductive endpoints such as mating performance, fertility, 
fecundity, litter survival, sperm morphology/vaginal cytology as well 
as the lack of histological change in the reproductive organs. The 
LOAEL was not identified for reproductive toxicity, suggesting that the 
test animals could have tolerated a higher dose.
    Based on the reproductive toxicity data submitted for this 
expansion to the tolerance exemption, which showed no adverse 
reproductive effects at the highest dose tested, 7,500 ppm (equivalent 
to 441 to 591 mg/kg/day in parental male and female rats and 776 to 839 
mg/kg/day in F1 males and females, respectively), there are 
sufficient data and information to confirm that 1,4-DMN is not a 
reproductive toxicant, and that consumption of food commodities that 
have been treated with this substance when used as a pesticide is safe 
and will not result in any harm to human health from dietary exposure.
    5. A combined chronic toxicity and carcinogenicity study (MRID 
48590907) was conducted on rats (65 rats/sex/group for carcinogenicity 
and 20 rats/sex/group for chronic toxicity) to assess the chronic 
toxicity and carcinogenicity potential for 1,4-DMN. 1,4-DMN was 
administered in the diet of rats 7 days/week for a minimum of 52 weeks 
(chronic toxicity phase) or 104 weeks (carcinogenicity phase), at the 
dose concentrations of 0, 150, 500, and 3,750 ppm, equivalent to the 
dose concentrations of 0, 10, 33, and 250 mg/kg/day. For the chronic 
study, decreased food consumption with concurrent decreases in body 
weight and body weight gain were noted in the 250 mg/kg/day dose group. 
Minimal to moderate histologic test material-related effects in the 
kidney (proteinosis, papillary necrosis and karyomegaly) were noted in 
male rats at 250 mg/kg/day, while minimal to mild karyomegaly was noted 
in the kidney of female rats administered 1,4-DMN at dosages of 33 or 
250 mg/kg/day. Based on the results of the chronic toxicity study, the 
NOAEL for chronic toxicity was 33 mg/kg/day for males and 10 mg/kg/day 
for females. For the carcinogenicity study, no incidences of 
carcinogenicity were noted in rats in any of the dose concentrations 
after the 97 weeks and 104 weeks of treatment for female and male rats, 
respectively.
    Based on the results of the carcinogenicity data submitted for this 
expansion to the tolerance exemption, which showed that there was no 
evidence of carcinogenicity at the highest dose tested, 3,750 ppm 
(equivalent to 250 mg/kg/day), there are sufficient data and 
information to confirm that 1,4-DMN is not a carcinogen, and that 
consumption of food commodities that have been treated with this 
substance when used as a pesticide is safe and will not result in any 
harm to human health from dietary exposure.

IV. Aggregate Exposures

    In examining aggregate exposure, FFDCA section 408 directs EPA to 
consider available information concerning exposures from the pesticide 
residue in food and all other non-occupational exposures, including 
drinking water from ground water or surface water and exposure through 
pesticide use in gardens, lawns, or buildings (residential and other 
indoor uses).

A. Dietary Exposure

    Dietary risks to humans are considered negligible based on the lack 
of significant dietary toxicological endpoints for 1,4-DMN, its non-
toxic mode of action, and the fact that it is applied to postharvest 
root, tuber, and bulb crops at the relatively low application rate of 
20 ppm up to four applications during the storage season. No 
significant acute, subchronic, mutagenic, developmental, chronic, or 
carcinogenicity dietary toxicity hazards were identified in the studies 
submitted to support this expansion of the tolerance exemption or the 
previous tolerance exemption (60 FR 7456). The submitted data and 
information for this expansion of the tolerance exemption show that any 
residues of 1,4-DMN found in or on the sprouting root, tuber, and bulb 
crops are far below any toxicological endpoints identified in this 
expansion of the tolerance exemption or in the previous tolerance 
exemption (60 FR 7456) and confirm 1,4-DMN's lack of dietary toxicity 
hazards for mammals (Ref. 2).
    1. Food. The petitioner submitted a scientific literature summary 
of the natural occurrence of 1,4-DMN in food crops (MRID 48653101) to 
support the expansion of the tolerance exemption from postharvest use 
on potatoes only, which are found in EPA Crop Group 01, to include all 
other sprouting root and tuber vegetables in the same EPA Crop Group 01 
and all bulb vegetables (EPA Crop Group 03). Bulb vegetables include 
garlic, leek, onion, rakkyo, and shallot. As stated in the summary, 
1,4-DMN has been detected in various crops including cocoa, coffee, 
apples, corn, raisins, tomatoes, apricots, peaches, pear juice, 
eggplants, green peppers, star fruit, tea, radishes (EPA Crop Group 
01), oranges, cinnamon, poppies, and red beans (Ref. 1). It is likely 
that 1,4-DMN occurs naturally in other crops not listed in the 
literature summary, including crops in EPA Crop Group 01 (besides the 
already listed potatoes and radishes), and bulb crops in EPA Crop Group 
03. The literature summary also indicated that the isomers of 
dimethylnaphthalene were shown to be present in various crops; however, 
the research indicates that it is extremely difficult to measure the 
amounts of the natural occurrence due to the volatility of the 
dimethylnaphthalene isomers, and any amounts reported are most likely 
an underestimation of the actual amount naturally present in the crop. 
As stated in Unit III of this final rule, the previous tolerance 
exemption (60 FR 7456) indicated that 1,4-DMN is found naturally 
occurring in potatoes. When conditions are right for sprouting, the 
potato metabolizes 1,4-DMN to a low enough level so that sprouting can 
occur. 1,4-DMN is applied to postharvest potatoes at a level, generally 
20 ppm up to four applications during a storage season, to maintain 
1,4-DMN at a sufficient concentration in the potato to continue to 
inhibit sprouting.
    Based on the submitted data and information for this expansion of 
the tolerance exemption, any residues of 1,4-DMN found in or on the 
sprouting root, tuber, and bulb crops are far below any toxicological 
endpoints identified in this expansion of the tolerance exemption or in 
the previous tolerance exemption (60 FR 7456). These toxicological 
endpoints identified in Unit III of this final rule include: Maternal 
toxicity NOAEL of 80 mg/kg/day, developmental toxicity NOAEL greater 
than 250 mg/kg/day, reproductive toxicity NOAEL of 7,500 ppm 
(equivalent to 441 to 591 mg/kg/day in parental male and female rats 
and 776 to 839 mg/kg/day in F1 males and females, 
respectively), and chronic toxicity NOAEL of 33 mg/kg/day (500 ppm) for 
males and 10 mg/kg/day (150 ppm) for females. The previous tolerance 
exemption showed an acute oral toxicity LD50 of 2,730 mg/kg/
day. In addition, under the conditions of the respective studies, there 
were no signs of mutagenicity or carcinogenicity for 1,4-DMN. In 
summary, the toxicity data

[[Page 68696]]

submitted for 1,4-DMN, the natural occurrence of the substance in the 
various crops listed in this section, the nontoxic mode of action, the 
volatility of the isomers of dimethylnaphthalene, and the fact that it 
is applied to postharvest root, tuber, and bulb crops at the relatively 
low application rate of 20 ppm up to four applications during the 
storage season, demonstrate a lack of aggregate dietary risk that is 
sufficient to support this expansion of the tolerance exemption.
    2. Drinking water exposure. No new drinking water exposure is 
expected to result from the new food uses of 1,4-DMN. Exposure of 
humans to 1,4-DMN in drinking water is highly unlikely since the 
products are labeled for postharvest application to sprouting root, 
tuber, and bulb crops stored in indoor facilities and are not applied 
directly to crops in the field. The data and information demonstrate a 
lack of aggregate dietary risk via drinking water and is sufficient to 
support this expansion of the tolerance exemption.

B. Other Non-Occupational Exposure

    No new non-occupational exposure is expected to result from the new 
food uses of 1,4-DMN. No health risks are expected from any non-
occupational exposure to 1,4-DMN based on the data submitted for the 
previous tolerance exemption (60 FR 7456) and for this expansion of the 
tolerance exemption.
    1. Dermal exposure. No new non-occupational dermal exposure is 
expected to result from the new food uses of 1,4-DMN resulting from 
this expansion of the tolerance exemption. Any new dermal exposure 
associated with this expansion of the tolerance exemption is expected 
to be occupational in nature.
    2. Inhalation exposure. No new non-occupational inhalation exposure 
is expected to result from the new food uses of 1,4-DMN resulting from 
this expansion of the tolerance exemption. Any new inhalation exposure 
associated with this expansion of the tolerance exemption is expected 
to be occupational in nature.

V. 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 1,4-DMN to share a common mechanism of toxicity 
with any other substances, and 1,4-DMN does not appear to produce a 
toxic metabolite produced by other substances. For the purposes of this 
tolerance action, therefore, EPA has assumed that 1,4-DMN 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://www.epa.gov/pesticides/cumulative.

VI. Determination of Safety for U.S. Population, Infants and Children

    FFDCA section 408(b)(2)(C) provides that EPA shall assess the 
available information about consumption patterns among infants and 
children, special susceptibility of infants and children to pesticide 
chemical residues, and the cumulative effects on infants and children 
of the residues and other substances with a common mechanism of 
toxicity. In addition, FFDCA section 408(b)(2)(C) provides that EPA 
shall apply an additional tenfold margin of safety for infants and 
children in the case of threshold effects to account for prenatal and 
postnatal toxicity and the completeness of the database unless EPA 
determines that a different margin of safety will be safe for infants 
and children. Margins of exposure (safety), which are often referred to 
as uncertainty factors, are incorporated into EPA risk assessments 
either directly or through the use of a margin of exposure analysis, or 
by using uncertainty (safety) factors in calculating a dose level that 
poses no appreciable risk.
    Relevant data and information submitted for the previous tolerance 
exemption (60 FR 7456) and for this expansion of the tolerance 
exemption indicate that 1,4-DMN has negligible acute, subchronic, 
mutagenic, developmental, chronic, or carcinogenicity toxicity hazards. 
Moreover, 1,4-DMN has a nontoxic mode of action and naturally occurs in 
various crops as listed in Unit IV.A.1. Therefore, the Agency concludes 
that there is a reasonable certainty that no harm will result to the 
U.S. population, including infants and children, from aggregate 
exposure to the residues of 1,4-DMN. This includes all anticipated 
dietary exposures and all other exposures for which there is reliable 
information. EPA has arrived at this conclusion because the data and 
information available on 1,4-DMN do not demonstrate significant toxic 
potential to mammals. Thus, there are no threshold effects of concern 
and, as a result, an additional margin of safety is not necessary.

VII. Other Considerations

A. Analytical Enforcement Methodology

    An analytical method is not required for enforcement purposes for 
the reasons stated above, and because EPA is establishing an exemption 
from the requirement of a tolerance without any numerical limitation.

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 1,4-DMN.

VIII. Conclusions

    EPA concludes that there is a reasonable certainty that no harm 
will result to the U.S. population, including infants and children, 
from aggregate exposure to residues of 1,4-DMN. Therefore, the existing 
exemption from the requirement of a tolerance for residues of the plant 
growth regulator, 1,4-DMN, when applied postharvest to potatoes is 
amended by establishing the exemption from the requirement of a 
tolerance for residues of the plant growth regulator, 1,4-DMN, when 
applied postharvest to sprouting root, tuber, and bulb crops in 
accordance with good agricultural practices.

IX. References

    The following references used in this document and the previous 
Final Rule published in the Federal Register on February 8, 1995, (60 
FR 7456) (FRL-4932-4) are in the OPP docket listed under docket ID EPA-
HQ-OPP-2011-1029 and may be seen by accessing the www.regulations.gov 
Web site.
    1. U.S. EPA. 2012. Memorandum from Gina M. Burnett to Colin Walsh. 
Science Review of Tolerance Petition 1F7920,

[[Page 68697]]

Intended to Expand the Use of 1,4-Dimethylnaphthalene to Include Use on 
All Root and Tuber Vegetables (Crop Group 01) and Bulb Vegetables (Crop 
Group 03); Label Amendments for 67727-1, -3 and -4 Upon Tolerance 
Amendment Approval. U.S. Environmental Protection Agency, Office of 
Pesticide Programs. March 16, 2012.
    2. U.S. EPA. 2012. Memorandum from Russell S. Jones, Ph.D., to 
Colin Walsh. Science Review of Registrant's Response to Deficiencies in 
Tolerance Petition 1F7920, Intended to Expand the Use of 1,4-
Dimethylnaphthalene to Include Use on All Root and Tuber Vegetables 
(Crop Group 01) and Bulb Vegetables (Crop Group 03); Label Amendments 
for 67727-1, -3 and -4 Upon Tolerance Amendment Approval. U.S. 
Environmental Protection Agency, Office of Pesticide Programs. June 21, 
2012.

X. Statutory and Executive Order Reviews

    This final rule establishes an exemption from the requirement of a 
tolerance under FFDCA section 408(d) in response to a petition 
submitted to the Agency. The Office of Management and Budget (OMB) has 
exempted these types of actions from review under Executive Order 
12866, 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 
exemption 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 
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).

XI. 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: October 26, 2012.
Keith A. Mathews,
Director, Biopesticides and Pollution Prevention Division, Office of 
Pesticide Programs.

    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. Revise Sec.  180.1142 to read as follows:

Sec.  180.1142  1,4-Dimethylnaphthalene; exemption from the requirement 
of a tolerance.

    An exemption from the requirement of a tolerance is established for 
the residues of the plant growth regulator, 1,4-dimethylnaphthalene 
(1,4-DMN), when applied postharvest to all sprouting root, tuber, and 
bulb crops in accordance with good agricultural practices.
[FR Doc. 2012-27809 Filed 11-15-12; 8:45 am]
BILLING CODE 6560-50-P