Document ID: EPA-HQ-OPP-2009-0802-0004
Agency: epa
Document Type: Rule
Title: 2,6-Diisopropylnaphthalene (2,6-DIPN); Time-Limited Pesticide Tolerances
Posted Date: 2009-12-16T05:00Z

[Federal Register: December 16, 2009 (Volume 74, Number 240)]
[Rules and Regulations]               
[Page 66574-66580]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr16de09-11]                         

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[EPA-HQ-OPP-2009-0802; FRL-8798-5]

 
2,6-Diisopropylnaphthalene (2,6-DIPN); Time-Limited Pesticide 
Tolerances

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This regulation establishes time-limited tolerances for 
residues of 2,6-diisopropylnaphthalene (2,6-DIPN), including its 
metabolites and degradates, resulting from post-harvest applications to 
potatoes, in or on various commodities. Loveland Products, Incorporated 
requested these tolerances under the Federal Food, Drug, and Cosmetic 
Act (FFDCA). The tolerances will expire on May 18, 2012.

DATES: This regulation is effective December 16, 2009. Objections and 
requests for hearings must be received on or before February 16, 2010, 
and must be filed in accordance with the instructions provided in 40 
CFR part 178 (see also Unit I.C. of the SUPPLEMENTARY INFORMATION).

ADDRESSES: EPA has established a docket for this action under docket 
identification (ID) number EPA-HQ-OPP-2009-0802. All documents in the 
docket are listed in the docket index available at http://
www.regulations.gov. Although listed in the index, some information is 
not publicly available, e.g., Confidential Business Information (CBI) 
or other information whose disclosure is restricted by statute. Certain 
other material, such as copyrighted material, is not placed on the 
Internet and will be publicly available only in hard copy form. 
Publicly available docket materials are available in the electronic 
docket at http://www.regulations.gov, or, if only available in hard 
copy, at the OPP Regulatory Public Docket in Rm. S-4400, One Potomac 
Yard (South Bldg.), 2777 S. Crystal Dr., Arlington, VA. The Docket 
Facility is open from 8:30 a.m. to 4 p.m., Monday through Friday, 
excluding legal holidays. The Docket Facility telephone number is (703) 
305-5805.

FOR FURTHER INFORMATION CONTACT: Leonard Cole, Biopesticides and 
Pollution Prevention Division (7511P), Office of Pesticide Programs, 
Environmental Protection Agency, 1200 Pennsylvania Ave., NW., 
Washington, DC 20460-0001; telephone number: (703) 305-5412; e-mail 
address: cole.leonard@epa.gov.

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this Action Apply to Me?

    You may be potentially affected by this action if you are an 
agricultural producer, food manufacturer, or pesticide manufacturer. 
Potentially affected entities may include, but are not limited to:
     Crop production (NAICS code 111).
     Animal production (NAICS code 112).
     Food manufacturing (NAICS code 311).
     Pesticide manufacturing (NAICS code 32532).
    This listing is not intended to be exhaustive, but rather provides 
a guide for readers regarding entities likely to be affected by this 
action. Other types of entities not listed in this unit could also be 
affected. The North American Industrial Classification System (NAICS) 
codes have been provided to assist you and others in determining 
whether this action might apply to certain entities. If you have any 
questions regarding the applicability of this action to a particular 
entity, consult the person listed under FOR FURTHER INFORMATION 
CONTACT.

B. How Can I Access Electronic Copies of this Document?

    In addition to accessing electronically available documents at 
http://www.regulations.gov, you may access this Federal Register 
document electronically through the EPA Internet under the ``Federal 
Register'' listings at http://www.epa.gov/fedrgstr. You may also access 
a frequently updated electronic version of 40 CFR part 180 through the 
Government Printing Office's e-CFR cite at http://www.gpoaccess.gov/
ecfr.

[[Page 66575]]

C. Can I File an Objection or Hearing Request?

    Under section 408(g) of FFDCA, 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. The EPA procedural regulations which 
govern the submission of objections and requests for hearings appear in 
40 CFR part 178. 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-2009-0802 in the subject line on the first page of 
your submission. All requests must be in writing, and must be mailed or 
delivered to the Hearing Clerk on or before February 16, 2010.
    In addition to filing an objection or hearing request with the 
Hearing Clerk as described in 40 CFR part 178, please submit a copy of 
the filing that does not contain any CBI for inclusion in the public 
docket that is described in ADDRESSES. Information not marked 
confidential pursuant to 40 CFR part 2 may be disclosed publicly by EPA 
without prior notice. Submit your copies, identified by docket ID 
number EPA-HQ-OPP-2009-0802, by one of the following methods.
     Federal eRulemaking Portal: http://www.regulations.gov. 
Follow the on-line instructions for submitting comments.
     Mail: Office of Pesticide Programs (OPP) Regulatory Public 
Docket (7502P), Environmental Protection Agency, 1200 Pennsylvania 
Ave., NW., Washington, DC 20460-0001.
     Delivery: OPP Regulatory Public Docket (7502P), 
Environmental Protection Agency, Rm. S-4400, One Potomac Yard (South 
Bldg.), 2777 S. Crystal Dr., Arlington, VA. Deliveries are only 
accepted during the Docket Facility's normal hours of operation (8:30 
a.m. to 4 p.m., Monday through Friday, excluding legal holidays). 
Special arrangements should be made for deliveries of boxed 
information. The Docket Facility telephone number is (703) 305-5805.

II. Background and Statutory Findings

    In the Federal Register of October 21, 2009 (74 FR 54043) (FRL-
8795-7), EPA issued a notice pursuant to section 408(d)(3) of the 
FFDCA, 21 U.S.C. 346a(d)(3), announcing the filing of a pesticide 
petition (PP 9F7626) by Loveland Products, Inc., 7251 W. 4th Street, 
Greeley, CO 80634. The petition requested that 40 CFR part 180 be 
amended by establishing tolerances for residues of the biochemical 
pesticide 2,6-DIPN in or on the following food commodities: Cattle, fat 
at 0.8 ppm; cattle, liver at 0.3 ppm; cattle, meat at 0.1 ppm; cattle, 
meat byproducts at 0.1 ppm; goat, fat at 0.8 ppm; goat, liver at 0.3 
ppm; goat, meat at 0.1 ppm; goat, meat byproducts at 0.1 ppm; hog, fat 
at 0.8 ppm; hog, liver at 0.3 ppm; hog, meat at 0.1 ppm; hog, meat 
byproducts at 0.1 ppm; horse, fat at 0.8 ppm; horse, liver at 0.3 ppm; 
horse, meat at 0.1 ppm; horse, meat byproducts at 0.1 ppm; milk at 0.1 
ppm; potato at 2.0 ppm; potato, wet peel at 6.0 ppm; sheep, fat at 0.8 
ppm; sheep, liver at 0.3 ppm; sheep, meat at 0.1 ppm; and sheep, meat 
byproducts at 0.1 ppm. The proposed tolerance levels were based on 
results of studies on the magnitude of 2,6-DIPN in potatoes and 
processed potatoes and in livestock edible commodities.
    The Agency failed to include a summary of the petition prepared by 
Loveland Products, Incorporated, the petitioner, in the docket; 
therefore, the Agency placed the summary of the petition in the docket 
and reopened the comment period (74 FR 57467; November 6, 2009) (FRL-
8798-4).
    One comment was received in response to the October 21, 2009 
notice. In general, a private citizen expressed opposition to the 
establishment of the numeric tolerances sought by the petitioner.
    Comment: The commenter objected to the manufacture, sale, and use 
of pesticide products containing 2,6-DIPN in the United States (U.S.) 
and asserted that EPA does not possess sufficient data to ascertain 
whether 2,6-DIPN products are truly harmful to human health. 
Furthermore, the commenter articulated the following opinions: ``It is 
also clear that our waters are being deluged with toxic chemicals 
courtesy of this Agency approving 100% of all toxic chemicals that come 
before it. This Agency is harmfully impacting the people of the United 
States and this Agency needs to have fired many of its employees. Bush 
put lobbyists in charge of it and those guys just sank down to their 
knees for toxic chemical polluters. The situation is bad and 
desperately needs correction.''
    EPA Response: The toxicity of 2,6-DIPN has been examined thoroughly 
by the Agency, and the data show that when 2,6-DIPN is used in 
accordance with EPA-approved labeling and good agricultural practices, 
there is a reasonable certainty of no harm to human health. Given the 
available data, the Agency has established numeric tolerances for 2,6-
DIPN that are safe.
    Based upon review of the data supporting the petition, EPA has 
increased the petitioned-for tolerance levels for all of the livestock 
commodities and added two new tolerances for ``milk, fat'' and 
``potatoes, granules/flakes.'' EPA also revised commodity terms, as 
necessary, to agree with the Agency's Food and Feed Commodity 
Vocabulary. The Agency is also issuing time-limited tolerances at this 
time instead of permanent tolerances. The reasons for these changes are 
explained in Unit IV.E.

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. . . 
.''
    EPA performs a number of analyses to determine the risks from 
aggregate exposure to pesticide residues. For further discussion of the 
regulatory requirements of section 408 of the FFDCA and a complete 
description of the risk assessment process, see http://www.epa.gov/
fedrgstr/EPA-PEST/1997/November/Day-26/p30948.htm.
    Consistent with section 408(b)(2)(D) of FFDCA, EPA has reviewed the 
available scientific data and other relevant information in support of 
this action. EPA has sufficient data to assess the hazards of and to 
make a determination on aggregate exposure, consistent with section 
408(b)(2) of FFDCA, for time-limited tolerances for residues of 2,6-
DIPN, including its metabolites and degradates, in or on cattle, fat at 
1.0 ppm; cattle, liver at 0.5 ppm; cattle, meat at 0.2 ppm; cattle, 
meat byproducts (except liver) at 0.4 ppm; goat, fat at 1.0 ppm; goat, 
liver at 0.5 ppm; goat, meat at 0.2 ppm; goat, meat byproducts (except 
liver) at 0.4 ppm; hog, fat at 1.0 ppm; hog, liver at 0.5 ppm; hog, 
meat at 0.2 ppm; hog, meat byproducts (except liver) at 0.4

[[Page 66576]]

ppm; horse, fat at 1.0 ppm; horse, liver at 0.5 ppm; horse, meat at 0.2 
ppm; horse, meat byproducts (except liver) at 0.4 ppm; milk at 0.2 ppm; 
milk, fat at 0.5 ppm; potato at 2.0 ppm; potato, wet peel at 6.0 ppm; 
potato, granules/flakes at 5.5 ppm; sheep, fat at 1.0 ppm; sheep, liver 
at 0.5 ppm; sheep, meat at 0.2 ppm; and sheep, meat byproducts (except 
liver) at 0.4 ppm. EPA's assessment of the dietary exposures and risks 
associated with establishing the time-limited tolerances follows.

A. Toxicological Profile

    EPA has evaluated the available toxicity data and considered its 
validity, completeness, and reliability as well as the relationship of 
the results of the studies to human risk. EPA has also considered 
available information concerning the variability of the sensitivities 
of major identifiable subgroups of consumers, including infants and 
children. The nature of the toxic effects caused by 2,6-DIPN are 
discussed in this unit.
    Time-limited tolerances for 2,6-DIPN expired on August 1, 2009 (40 
CFR 180.590). To evaluate the tolerances requested in the subject 
petition, EPA reviewed data unavailable for the previous, time-limited 
tolerances. In support of this rule, EPA is providing a discussion of 
the toxicity of 2,6-DIPN in light of the newly submitted data. 
Evaluation of these data indicates that the toxicity profile of 2,6-
DIPN has not been affected. Based on this finding, the Agency can make 
a determination of reasonable certainty of no harm to human health when 
residues of 2,6-DIPN, including its metabolites and degradates, within 
the tolerance levels established by this final rule are consumed from 
the aforementioned commodities.
    2,6-DIPN is classified as a biochemical-like active ingredient, 
primarily based upon its structural and functional similarities to the 
following naturally occurring plant growth regulators: 1-Isopropyl-4,6-
dimethylnaphthalene; 1-methyl-7-isopropylnaphthalene; and 4-isopropyl-
1,6-dimethylnaphthalene. 2,6-DIPN behaves as a sprout inhibitor; 
therefore, the Agency considers this mode of action to be non-toxic. 
With regard to the toxicity of 2,6-DIPN to humans (including infants 
and children), as a result of consumption of potatoes treated with this 
active ingredient after harvest, the Agency has, since 2,6-DIPN's 
initial registration in 2003, continued to evaluate this active 
ingredient for its toxicity and safety to the general population. EPA's 
discussion and analysis of the toxicological profile of 2,6-DIPN can be 
found in the Federal Register of September 1, 2006 (71 FR 52003) (FRL-
8081-9), and August 8, 2003 (68 FR 47246) (FRL-7321-6).
    In support of these current time-limited tolerances, EPA did not 
assess any new toxicity data on 2,6-DIPN. EPA has previously conducted 
comprehensive evaluations of the potential human health and dietary 
toxicity of 2,6-DIPN. As mentioned above (see Unit III.A.2.), EPA 
reviewed newly submitted nature of residue data conducted on plants and 
livestock (For a detailed discussion of these data, see Unit IV.A.). 
These data are required by the Agency to demonstrate the fate and 
distribution of the active ingredient and its metabolites in plants and 
livestock. These data enable the Agency to better understand if any 
metabolites of the active ingredient contribute to the toxicity of the 
active ingredient being evaluated and require an increase or decrease 
in proposed tolerance levels. Moreover, this information ultimately may 
or may not impact the Agency's risk assessment. In the case of the 
evaluation of these newly submitted data in support of these time-
limited tolerances and a reevaluation of field trial data on file 
(Master Record Identification Number (MRID No.) 451632-02), the Agency 
has concluded that the toxicity profile of 2,6-DIPN has not changed, 
nor does the original risk assessment for this active ingredient 
change. In further support of this assertion, the Agency also 
considered potato processing data, which demonstrates that residues of 
2,6-DIPN were found not to concentrate in baked potatoes, boiled 
potatoes, and french fries (MRID No. 448660-01). In consideration of 
all of the previously explained information, EPA concludes that 
residues of 2,6-DIPN, including its metabolites and degradates within 
the tolerance limits established by this final rule will present no 
harm to human health when used in accordance with EPA-approved labeling 
and good agricultural practices. Included in this document is a summary 
of the toxicity findings to date from both acute and chronic 
perspectives (see Unit III.B.).
    Additionally, EPA concludes that the analytical methods submitted 
to enforce the time-limited tolerance levels established for 2,6-DIPN 
residues in potato and potato peels (MRID Nos. 464749-01 and 464749-02, 
respectively) are adequate for the purpose of establishing these 
tolerances for 2,6-DIPN. But, a revised analytical method for the 
analysis of 2,6-DIPN and its metabolites in livestock commodities 
remains inadequate. Data reviewed in support of these time-limited 
tolerances support validation of the analytical method for the parent 
compound in livestock commodities only, while an independent laboratory 
validation demonstrating the suitability of the analytical method for 
the metabolites and degradates in livestock commodities and a 
radiovalidation are still required. The need for these data will be set 
as conditions of registration.

B. Toxicological Endpoints

    1. Acute toxicity. While EPA's discussion and analysis of acute 
toxicity of 2,6-DIPN can be found in the Federal Register of August 8, 
2003 (68 FR 47246), in summary, 2,6-DIPN is classified as Toxicity 
Category IV for the oral route of exposure (lethal dose 
(LD)50 >5,000 milligrams/kilogram (mg/kg)).
    2. Short- and intermediate-term toxicity. While EPA's complete 
discussion and analysis of short- and intermediate-term toxicity of 
2,6-DIPN can be found in the Federal Register of August 8, 2003 (68 FR 
47246), a summary is provided here. The subchronic toxicity study 
submitted and reviewed suggests the endpoint selection (value/dose at 
which an effect was observed) is the 104 milligrams/kilogram/day (mg/
kg/day) no observable adverse effects level (NOAEL) based on reduced 
body weight, weight gain, and food consumption. Although the 
developmental toxicity study indicated a lower NOAEL (50 mg/kg/day) for 
the same toxicity, the maternal lowest observable adverse effects level 
(LOAEL) of 150 mg/kg/day is between the subchronic NOAEL of 104-121 mg/
kg/day and the LOAEL of 208-245 mg/kg/day. The NOAEL of 50 mg/kg/day 
may have been appropriate for use in characterization of risks for the 
subpopulation of women of childbearing age; however, the response at 50 
mg/kg/day in the developmental study was minimal and the observations 
for toxic effects were more thoroughly documented in the subchronic 
study.
    3. Chronic toxicity. EPA has established the Reference Dose (RfD) 
for 2,6-DIPN at 1 mg/kg/day. This RfD is based on results from the 
subchronic and developmental toxicity studies described in the Federal 
Register of September 1, 2006 (71 FR 52003) (FRL-8081-9). In support of 
these tolerances, the RfD remains unchanged.
    4. Carcinogenicity. No new study results suggest that 2,6-DIPN is 
carcinogenic. See EPA's discussion and analysis in the Federal Register 
of August 8, 2003 (68 FR 47246).

[[Page 66577]]

C. Exposures and Risks

    1. From food and feed uses. The Agency is establishing time-limited 
tolerances for the residues of 2,6-DIPN, including its metabolites and 
degradates, in or on cattle, fat at 1.0 ppm; cattle, liver at 0.5 ppm; 
cattle, meat at 0.2 ppm; cattle, meat byproducts (except liver) at 0.4 
ppm; goat, fat at 1.0 ppm; goat, liver at 0.5 ppm; goat, meat at 0.2 
ppm; goat, meat byproducts (except liver) at 0.4 ppm; hog, fat at 1.0 
ppm; hog liver at 0.5 ppm; hog, meat at 0.2 ppm; hog, meat byproducts 
(except liver) at 0.4 ppm; horse, fat at 1.0 ppm; horse, liver at 0.5 
ppm; horse, meat at 0.2 ppm; horse, meat byproducts (except liver) at 
0.4 ppm; milk at 0.2 ppm; milk, fat at 0.5 ppm; potato at 2.0 ppm; 
potato, granules/flakes at 5.5 ppm; potato, wet peel at 6.0 ppm; sheep, 
fat at 1.0 ppm; sheep, liver at 0.5 ppm; sheep, meat at 0.2 ppm; and 
sheep, meat byproducts (except liver) at 0.4 ppm.
    Acute dietary 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. 
In the case of 2,6-DIPN, the toxicity data base did not indicate an 
acute endpoint, but the 100 mg/kg/day NOAEL from the subchronic 
toxicity study (rounded from 104 mg/kg/day) was used to evaluate 
potential acute dietary exposure as a conservative basis for risk 
characterization. Also, if the 50 mg/kg/day NOAEL from the 
developmental toxicity study had been used to establish an acute RfD, 
this choice would have been inconsistent with the use of the 100 mg/kg/
day NOAEL since it implies that exposure to repeated daily doses at 100 
mg/kg/day is potentially less hazardous than a single dose at 50 mg/kg/
day. Given the minimal nature of the responses in the subchronic and 
developmental toxicity studies, and the fact that the NOAEL from the 
developmental study is only appropriate to the subgroup of females 13-
49 years of age, using the 100 mg/kg/day RfD for the acute and chronic 
dietary assessments is more appropriate for assessing risk for other 
subgroups and the general population. Therefore, a conservative 
interpretation of these endpoints indicated the need for an acute 
dietary exposure assessment. The 100 mg/kg/day endpoint was also 
interpreted as requiring a chronic dietary exposure assessment.
    Acute and chronic dietary exposure assessments for 2,6-DIPN were 
conducted using the Dietary Exposure Evaluation Model software 
(DEEM\TM\ version 1.30), which incorporates consumption data from the 
United States Department of Agriculture's Continuing Surveys of Food 
Intakes by Individuals (CSFII, 1994-1996/1998).
    For acute exposure assessments, individual 1-day food consumption 
data define an exposure distribution, which is expressed as a 
percentage of the acute population adjusted dose (aPAD) (for 2,6-DIPN, 
aPAD = 0.1 mg/kg/day). For chronic exposure and risk assessment, an 
estimate of the residue level in each food or food-form (e.g., orange 
or orange juice) on the commodity residue list is multiplied by the 
average daily consumption estimate for the food or food-form. The 
resulting residue consumption estimate for each food or food-form is 
summed with the residue consumption estimate for all other food or 
food-forms on the commodity residue list to arrive at the total 
estimated exposure. Exposure estimates are expressed as mg/kg body 
weight/day and as a percent of the 2,6-DIPN chronic population adjusted 
dose (cPAD) (0.1 mg/kg/day). These procedures are performed for each 
population subgroup.
    2. From drinking water. Because 2,6-DIPN treatment of stored (i.e., 
post-harvest) potato occurs inside (in warehouses, for example), no 
concern from exposure through water is expected regarding acute and 
chronic dietary risk assessment. For this reason, the dietary risk 
assessment did not include drinking water values.
    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). 2,6-DIPN is not 
registered for use on any sites that would result in residential 
exposure. Furthermore, because the registered use involves applications 
via a closed system, no exposure of consequence is expected to mixers 
or loaders.
    4. Cumulative effects from substances with a common mechanism of 
toxicity. Section 408(b)(2)(D)(v) of the FFDCA requires that, when 
considering whether to establish, modify, or revoke a tolerance, the 
Agency consider ``available information'' concerning the cumulative 
effects of a particular pesticide's residues and ``other substances 
that have a common mechanism of toxicity.''
    Unlike other pesticides for which EPA has followed a cumulative 
risk approach based on a common mechanism of toxicity, EPA has not made 
a common mechanism of toxicity finding as to 2,6-DIPN and any other 
substances. In this case, 2,6-DIPN, as well as the three functionally 
and structurally similar substances, all act as plant regulators by a 
``mode of action'' that is specific to plants, and therefore, their 
common mode of action is unlikely to be relevant to a mechanism of 
toxicity in animals or humans. The comparison of 2,6-DIPN with three 
naturally occurring, alkyl-substituted naphthalenes is made to 
demonstrate biological activity (plant regulation, in this case), which 
the Agency has characterized as a non-toxic mode of action with respect 
to pesticidal activity. For the purposes of this tolerance action, 
therefore, EPA has not assumed that 2,6-DIPN has a common mechanism of 
toxicity with other substances. For information regarding EPA's efforts 
to determine which chemicals have a common mechanism of toxicity and to 
evaluate the cumulative effects of such chemicals, see the policy 
statements released by EPA's Office of Pesticide Programs concerning 
common mechanism determinations and procedures for cumulating effects 
from substances found to have a common mechanism on EPA's website at 
http://www.epa.gov/pesticides/cumulative.

D. Aggregate Risks and Determination of Safety for U.S. Population and 
for Infants and Children

    1. Acute risk. Acute dietary exposure estimates were based on the 
tolerances (i.e., the tolerance levels as established in this final 
rule supported by the residue trial results) and worst-case 
assumptions.
    As reported in the Federal Register of August 8, 2003 (68 FR 
47246), EPA established a RfD of 1 mg/kg/day, and an aPAD and cPAD of 
0.1 mg/kg/day.
    The Acute Dietary Exposure Analysis was based on the following 
tolerance levels for the residues of 2,6-DIPN, including its 
metabolites and degradates: in or on cattle, fat at 1.0 ppm; cattle, 
liver at 0.5 ppm; cattle, meat at 0.2 ppm; cattle, meat byproducts 
(except liver) at 0.4 ppm; goat, fat at 1.0 ppm; goat, liver at 0.5 
ppm; goat, meat at 0.2 ppm; goat, meat byproducts (except liver) at 0.4 
ppm; hog, fat at 1.0 ppm; hog, liver at 0.5 ppm; hog, meat at 0.2 ppm; 
hog, meat byproducts (except liver) at 0.4 ppm; horse, fat at 1.0 ppm; 
horse, liver at 0.5 ppm; horse, meat at 0.2 ppm; horse, meat byproducts 
(except liver) at 0.4 ppm; milk at 0.2 ppm; milk, fat at 0.5 ppm; 
potato at 2.0 ppm; potato, granules/flakes at 5.5 ppm; potato, wet peel 
at 6.0 ppm; sheep, fat at 1.0 ppm; sheep, liver at 0.5 ppm; sheep, meat 
at 0.2 ppm; and sheep, meat byproducts (except liver) at 0.4 ppm;
    For the U.S. population, acute dietary exposure was estimated to be 
0.011459 mg/kg/day. This value represented

[[Page 66578]]

11.46% of the aPAD. The subpopulation with the highest acute dietary 
exposure estimate was children 1-2 years old (0.029362 mg/kg/day, 
29.36% of the aPAD). Therefore, the acute dietary exposures to all the 
subpopulations in the analysis did not exceed EPA's level of concern 
(i.e., they did not exceed 100% of the aPAD).
    2. Chronic risk. The chronic dietary risk estimates do not exceed 
EPA's level of concern (i.e., they do not exceed 100% of the cPAD). For 
the U.S. population, chronic dietary exposure was estimated to be 
0.003516 mg/kg/day. This value represented 3.5% of the cPAD. The 
subpopulation with the highest chronic dietary exposure estimate was 
children 1-2 years old (0.012173 mg/kg/day, 12.2% of the cPAD).
    3. Determination of safety. Based on these risk assessments and in 
consideration of new residue data, 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 
2,6-DIPN and its metabolites and degradates within the established 
tolerance limits resulting from post-harvest applications, undertaken 
in accordance with good agricultural practices and EPA-approved 
labeling, to potatoes. This includes all anticipated dietary exposures 
and all other exposures for which there is reliable information. In 
arriving at this conclusion, the Agency has retained the tenfold margin 
of safety in order to adequately account for potential pre- and post-
natal toxicity and completeness of the data with respect to exposure 
and toxicity to infants and children, pursuant to FFDCA section 
408(b)(2)(C).

IV. Other Considerations

A. Metabolism in Plants and Animals

    The metabolism study for stored potatoes treated with [\14\C-]-DIPN 
is ACCEPTABLE. The results indicate that significant amounts of [\14\C-
]-DIPN were lost during storage. Total Radioactive Residues (TRR) of 
2,6-DIPN decreased from 94.1% to 26.3% in whole potatoes from day 0 to 
178 days. The percentages of the TRR identified in the whole potato 
samples ranged from 70.2% to 95.3% (70.6% to 95.3% for potato peels).
    The four metabolites detected, which reached or exceeded 10% of the 
TRR in potato peels and whole potatoes, were M29, M22, M19, and M18. 
The metabolic pathway of 2,6-DIPN in potatoes demonstrates that these 
four metabolites are adequately understood. M29, a monohydroxy 
derivative of 2,6-DIPN, appeared first as a significant residue. The 
other major metabolites (M22, M19, and M18) were formed by metabolism 
of M29, which indicated that M29 was formed continuously throughout the 
study. However, based on residue declined data, these metabolites (M29, 
M22, M19, and M18) will not be included in tolerance setting because 
they showed an insignificant amount at day 0.
    The nature of the residue study in a lactating goat indicated that 
residues of 2,6-DIPN and its metabolites were distributed in muscle 
loin, muscle flank, fat renal, fat omental, fat subcutaneous, liver, 
kidney, blood, skim milk, and milk fat. The Agency has considered this 
information in evaluating the levels of 2,6-DIPN in livestock 
commodities and has incorporated residues of metabolites that exceed 
10% of the TRR in its risk assessment.
    The qualitative nature of the 2,6-DIPN residues in livestock 
commodities is adequately understood, based on a metabolism study. The 
four major metabolites (i.e., M14, M19, M27, and M29) were identified 
by high performance liquid chromatography/mass spectrometry (HPLC/MS) 
from samples of milk, muscles, fat, liver, and kidney.

B. Analytical Enforcement Methodology

    Loveland Products, Incorporated has proposed a liquid 
chromatographic/ultraviolet (LC/UV) detection analytical method for 
enforcement of tolerances for residues of 2,6-DIPN in potatoes and 
potato peels. The method (entitled, ``Liquid Chromatographic Analysis 
for the Determination of 2,6-Diisopropylnaphthalene (DIPN) in Potatoes 
and ``Liquid Chromatographic Analysis for the Determination of 2,6-
Diisopropylnaphthalene (DIPN) in Potato Peels'' (Platte Report Number 
CARDC-1298-DIPN)) was used for the determination of residues of 2,6-
DIPN in potatoes and potato peels.
    The method includes instructions and chromatograms for analysis of 
samples of potatoes and potato peels. Briefly, samples are extracted 
with acetonitrile. The extracts are partitioned with hexane. The 
acetonitrile part is discarded. The hexane part is roto-evaporated to 
dryness. The residues are reconstituted in hexane and purified using a 
Florisil column. The residues are roto-evaporated to dryness and 
reconstituted in acetonitrile. The samples are filtered through 
Acrodisc[reg] LC polyvinylidene difluoride (PVDF) 0.45 micrometer 
([mu]m) filters and analyzed by high performance liquid chromatography 
(HPLC) with ultraviolet (UV) detection at 254 nanometers (nm) using a 
Zorbax ODS column.
    The validated limit of quantitation (LOQ) is 0.01 ppm for 2,6-DIPN 
in potatoes and 0.02 ppm in potato peels. The reported limits of 
detection (LODs) were 0.001 ppm for 2,6-DIPN in potatoes and potato 
peels. The method does not include instructions for confirmatory 
analysis. Method validation data for the LC/UV method demonstrated 
adequate method recoveries of residues of 2,6-DIPN. Potato samples were 
fortified with 2,6-DIPN at levels of 0.01 ppm, 0.02 ppm, 0.05 ppm, and 
50 ppm. Samples were analyzed at the limit of quantitation of 0.01 ppm. 
Overall, recovery ranges (and CVs) from these matrices were 77.9-123.2 
(13.9%) for 2,6-DIPN. Potato peel samples were fortified with 2,6-DIPN 
at levels of 0.02 ppm, 0.05 ppm, and 0.2 ppm. Samples were analyzed at 
the limit of quantitation of 0.02 ppm. Overall, recovery ranges (and 
CVs) from these matrices were 83.2-96.1 (5.3%) for 2,6-DIPN.
    Acceptable independent laboratory validation is available for this 
method using potato and potato peel samples.
    As described above, an adequate enforcement methodology (liquid 
chromatographic/ultraviolet detection analytical method) is available 
to enforce the tolerance expression for potatoes and potato peels only.
    The method may be requested from: Chief, Analytical Chemistry 
Branch, Environmental Science Center, 701 Mapes Rd., Ft. Meade, MD 
20755-5350; telephone number: (410) 305-2905; e-mail address: 
residuemethods@epa.gov. As conditions of registration, the Agency is 
requesting a revised analytical method for the analysis of the 
metabolites of 2,6-DIPN in livestock commodities, an associated 
independent laboratory validation, and radiovalidation of this method. 
As stated Unit III.A., the Agency is requesting these data since the 
study analyzed the parent compound only.

C. International Residue Limits

    There are currently no established Codex Alimentarius Commission, 
Canadian, or Mexican Maximum Residue Levels (MRLs) for residues of 2,6-
DIPN in/on plant or livestock commodities. Therefore, no compatibility 
issues exist with regard to the proposed U.S. tolerances.

D. Rotational Crop Restrictions

    The rotational crop restrictions are not applicable for this 
petition because the commodity is for stored potatoes.

[[Page 66579]]

E. Revisions to the Requested Tolerances

    Based upon review of the data supporting the petition, EPA has 
slightly increased the tolerance levels requested in the petition for 
all of the livestock commodities and added two new tolerances for 
``milk, fat'' and ``potatoes, granules/flakes.'' EPA also revised 
commodity terms, as necessary, to agree with the Agency's Food and Feed 
Commodity Vocabulary.
    In light of review of the submitted nature of the residue data 
(lactating goat), the Agency slightly increased all of the livestock 
commodity tolerance levels to fully account for metabolites that 
exceeded 10% of the TRR. Additionally, EPA has set tolerance levels for 
milk, fat and potatoes, granules/flakes because residues of 2,6-DIPN 
would normally be expected to be present in these byproducts.
    While the petitioner requested permanent tolerances for residues of 
2,6 DIPN in or on the food commodities listed in this document, the 
Agency has determined that time-limited tolerances with an expiration 
date is appropriate in the absence of an analytical method for 
metabolites of 2,6-DIPN in livestock.

V. Conclusion

    Therefore, time-limited tolerances are established for residues of 
2,6-DIPN, including its metabolites and degradates, when applied post-
harvest to potatoes, in or on cattle, fat at 1.0 ppm; cattle, liver at 
0.5 ppm; cattle, meat at 0.2 ppm; cattle, meat byproducts (except 
liver) at 0.4 ppm; goat, fat at 1.0 ppm; goat, liver at 0.5 ppm; goat, 
meat at 0.2 ppm; goat, meat byproducts (except liver) at 0.4 ppm; hog, 
fat at 1.0 ppm; hog, liver at 0.5 ppm; hog, meat at 0.2 ppm; hog, meat 
byproducts (except liver) at 0.4 ppm; horse, fat at 1.0 ppm; horse, 
liver at 0.5 ppm; horse, meat at 0.2 ppm; horse, meat byproducts 
(except liver) at 0.4 ppm; milk at 0.2 ppm; milk, fat at 0.5 ppm; 
potato at 2.0 ppm; potato, granules/flakes at 5.5 ppm; potato, wet peel 
at 6.0 ppm; sheep, fat at 1.0 ppm; sheep, liver at 0.5 ppm; sheep, meat 
at 0.2 ppm; and sheep, meat byproducts (except liver) at 0.4 ppm.

VI. Statutory and Executive Order Reviews

    This final rule establishes tolerances under section 408(d) of 
FFDCA in response to a petition submitted to the Agency. The Office of 
Management and Budget (OMB) has exempted these types of actions from 
review under Executive Order 12866, entitled Regulatory Planning and 
Review (58 FR 51735, October 4, 1993). Because this final rule has been 
exempted from review under Executive Order 12866, this final rule is 
not subject to Executive Order 13211, entitled Actions Concerning 
Regulations That Significantly Affect Energy Supply, Distribution, or 
Use (66 FR 28355, May 22, 2001) or Executive Order 13045, entitled 
Protection of Children from Environmental Health Risks and Safety Risks 
(62 FR 19885, April 23, 1997). This final rule does not contain any 
information collections subject to OMB approval under the Paperwork 
Reduction Act (PRA), 44 U.S.C. 3501 et seq., nor does it require any 
special considerations under Executive Order 12898, entitled Federal 
Actions to Address Environmental Justice in Minority Populations and 
Low-Income Populations (59 FR 7629, February 16, 1994).
    Since tolerances and exemptions that are established on the basis 
of a petition under section 408(d) of FFDCA, such as the tolerance in 
this final rule, do not require the issuance of a proposed rule, the 
requirements of the Regulatory Flexibility Act (RFA) (5 U.S.C. 601 et 
seq.) do not apply.
    This final rule directly regulates growers, food processors, food 
handlers, and food retailers, not States or tribes, nor does this 
action alter the relationships or distribution of power and 
responsibilities established by Congress in the preemption provisions 
of section 408(n)(4) of FFDCA. As such, the Agency has determined that 
this action will not have a substantial direct effect on States or 
tribal governments, on the relationship between the national government 
and the States or tribal governments, or on the distribution of power 
and responsibilities among the various levels of government or between 
the Federal Government and Indian tribes. Thus, the Agency has 
determined that Executive Order 13132, entitled Federalism (64 FR 
43255, August 10, 1999) and Executive Order 13175, entitled 
Consultation and Coordination with Indian Tribal Governments (65 FR 
67249, November 9, 2000) do not apply to this final rule. In addition, 
this final rule does not impose any enforceable duty or contain any 
unfunded mandate as described under Title II of the Unfunded Mandates 
Reform Act of 1995 (UMRA) (Public Law 104-4).
    This action does not involve any technical standards that would 
require Agency consideration of voluntary consensus standards pursuant 
to section 12(d) of the National Technology Transfer and Advancement 
Act of 1995 (NTTAA), Public Law 104-113, section 12(d) (15 U.S.C. 272 
note).

VII. Congressional Review Act

    The Congressional Review Act, 5 U.S.C. 801 et seq., generally 
provides that before a rule may take effect, the agency promulgating 
the rule must submit a rule report to each House of the Congress and to 
the Comptroller General of the United States. EPA will submit a report 
containing this rule and other required information to the U.S. Senate, 
the U.S. House of Representatives, and the Comptroller General of the 
United States prior to publication of this final rule in the Federal 
Register. This final rule is not a ``major rule'' as defined by 5 
U.S.C. 804(2).

List of Subjects in 40 CFR Part 180

    Environmental protection, Administrative practice and procedure, 
Agricultural commodities, Pesticides and pests, Reporting and 
recordkeeping requirements.

    Dated: November 18, 2009.
Keith A. Matthews,
Acting Director, Biopesticides and Pollution Prevention Division, 
Office of Pesticide Programs.

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

PART 180--[AMENDED]

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

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

0
2. Section 180.590 is amended by revising paragraph (a) to read as 
follows:

Sec.  180.590  2,6-Diisopropylnaphthalene (2,6-DIPN); tolerances for 
residues.

    (a) General. (1) Time-limited tolerances are established for 
combined residues of 2,6-DIPN, including its metabolites and 
degradates, in or on the commodities in the table below as a result of 
the post-harvest application of 2,6-DIPN to potatoes, when 2,6-DIPN is 
used in accordance with good agricultural practices. Compliance with 
the tolerance levels specified below is to be determined by measuring 
only 2,6-DIPN in or on the commodities.

------------------------------------------------------------------------
                                                             Expiration/
                   Commodity                     Parts per    revocation
                                                  million        date
------------------------------------------------------------------------
Potato, granules/flakes.......................          5.5      5/18/12
Potato, wet peel..............................          6.0      5/18/12
Potato, whole.................................          2.0      5/18/12
------------------------------------------------------------------------

    (2) Time-limited tolerances are established for combined residues 
of 2,6-DIPN, including its metabolites and degradates, in or on the 
commodities in

[[Page 66580]]

the table below as a result of the post-harvest application of 2,6-DIPN 
to potatoes, when 2,6-DIPN is used in accordance with good agricultural 
practices. Compliance with the tolerance levels specified below is to 
be determined by measuring only 2,6-DIPN and the metabolites M14, M19, 
M27, and M29 in or on the commodities.

------------------------------------------------------------------------
                                                             Revocation/
                   Commodity                     Parts per    expiration
                                                  million        date
------------------------------------------------------------------------
Cattle, fat...................................          1.0      5/18/12
Cattle, liver.................................          0.5      5/18/12
Cattle, meat..................................          0.2      5/18/12
Cattle, meat byproducts.......................          0.4      5/18/12
Goat, fat.....................................          1.0      5/18/12
Goat, liver...................................          0.5      5/18/12
Goat, meat....................................          0.2      5/18/12
Goat, meat byproducts.........................          0.4      5/18/12
Hog, fat......................................          1.0      5/18/12
Hog, liver....................................          0.5      5/18/12
Hog, meat.....................................          0.2      5/18/12
Hog, meat byproducts..........................          0.4      5/18/12
Horse, fat....................................          1.0      5/18/12
Horse, liver..................................          0.5      5/18/12
Horse, meat...................................          0.2      5/18/12
Horse, meat byproducts........................          0.4      5/18/12
Milk, fat.....................................          0.5      5/18/12
Sheep, fat....................................          1.0      5/18/12
Sheep, liver..................................          0.5      5/18/12
Sheep, meat...................................          0.2      5/18/12
Sheep, meat byproducts........................          0.4      5/18/12
------------------------------------------------------------------------

* * * * *
[FR Doc. E9-29897 Filed 12-15-09; 8:45 am]

BILLING CODE 6560-50-S