[Federal Register Volume 78, Number 147 (Wednesday, July 31, 2013)]
[Rules and Regulations]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-18420]
ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
Trifluralin; Pesticide Tolerance
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
SUMMARY: This regulation establishes a tolerance for residues of
trifluralin in or on the oilseed crop group 20. Interregional Research
Project Number 4 (IR-4) requested this tolerance under the Federal
Food, Drug, and Cosmetic Act (FFDCA).
DATES: This regulation is effective July 31, 2013. Objections and
requests for hearings must be received on or before September 30, 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-2012-0304, 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: Lois Rossi, Registration Division
(7505P), Office of Pesticide Programs, Environmental Protection Agency,
1200 Pennsylvania Ave. NW., Washington, DC 20460-0001; telephone
number: (703) 305-7090; email address: RDFRNotices@epa.gov.
I. General Information
A. Does this action apply to me?
You may be potentially affected by this action if you are an
agricultural producer, food manufacturer, or pesticide manufacturer.
The following list of North American Industrial Classification System
(NAICS) codes is not intended to be exhaustive, but rather provides a
guide to help readers determine whether this document applies to them.
Potentially affected entities may include:
Crop production (NAICS code 111).
Animal production (NAICS code 112).
Food manufacturing (NAICS code 311).
Pesticide manufacturing (NAICS code 32532).
B. How can I get electronic access to other related information?
You may access a frequently updated electronic version of EPA's
tolerance regulations at 40 CFR part 180 through the Government
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-2012-0304 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
September 30, 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 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-2012-0304, by one of
the following methods:
Federal eRulemaking Portal: http://www.regulations.gov.
Follow the online instructions for submitting comments. Do not submit
electronically any information you consider to be CBI or other
information whose disclosure is restricted by statute.
Mail: OPP Docket, Environmental Protection Agency Docket
Center (EPA/DC), (28221T), 1200 Pennsylvania Ave. NW., Washington, DC
Hand Delivery: To make special arrangements for hand
delivery or delivery of boxed information, please follow the
instructions at http://www.epa.gov/dockets/contacts.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. Summary of Petitioned-For Tolerance
In the Federal Register of July 25, 2012 (77 FR 43562) (FRL-9353-
6), 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
2E8011) by IR-4, 500 College Road East, Suite 201W., Princeton, NJ
08540. The petition requested that 40 CFR 180.207 be amended by
establishing tolerances for residues of the herbicide trifluralin,
(alpha, alpha, alpha-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine),
in or on oilseed, crop group 20 at 0.05 parts per million (ppm). That
document referenced a summary of the petition prepared by Dow
AgroSciences, the registrant, which is available in the docket, http://www.regulations.gov. There were no comments received in response to the
notice of filing.
III. Aggregate Risk Assessment and Determination of Safety
Section 408(b)(2)(A)(i) of FFDCA allows EPA to establish a
tolerance (the legal limit for a pesticide chemical residue in or on a
food) only if EPA determines that the tolerance is ``safe.'' Section
408(b)(2)(A)(ii) of FFDCA defines ``safe'' to mean that ``there is a
reasonable certainty that no harm will result from aggregate exposure
to the pesticide chemical residue, including all anticipated dietary
exposures and all other exposures for which there is reliable
information.'' This includes exposure through drinking water and in
residential settings, but does not include occupational exposure.
Section 408(b)(2)(C) of FFDCA requires EPA to give special
consideration to exposure of infants and children to the pesticide
chemical residue in establishing a tolerance and to ``ensure that there
is a reasonable certainty that no harm will result to infants and
children from aggregate exposure to the pesticide chemical residue. . .
Consistent with 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 trifluralin including exposure
resulting from the tolerances established by this action. EPA's
assessment of exposures and risks associated with trifluralin follows.
A. Toxicological Profile
EPA has evaluated the available toxicity data and considered its
validity, completeness, and reliability as well as the relationship of
the results of the studies to human risk. EPA has also considered
available information concerning the variability of the sensitivities
of major identifiable subgroups of consumers, including infants and
The kidney and the liver are the principal target organs for
trifluralin in rats and dogs. In subchronic oral studies liver effects
include increased liver weights and changes in clinical chemistry
parameters. Kidney effects include decreased kidney weights, kidney and
bladder tumors, increased blood urea nitrogen (BUN), increases in total
protein, aspartate aminotransferase (AST) and lactate dehydrogenase
(LDH) in the urine. Also, protein electrophoresis of urine samples
showed [alpha]1-globulin and [alpha]2-globulin. Kidney effects also
included tubular hyaline casts, minimal cortical tubular
epithelial regeneration, observed microscopically, and an increased
incidence of progressive glomerulo-nephritis. In dogs exposed to
trifluralin for 1 year, multifocal cortical tubular cytoplasmic pigment
deposition was noted in the kidneys of both sexes. In the subchronic
studies, blood effects such as lower hemoglobin levels and changes in
clinical chemistry were reported in rats.
There was qualitative evidence of increased susceptibility in the
rat developmental toxicity study, where fetal developmental effects
(increased resorptions and wavy ribs) occurred in the presence of less
severe maternal effects (decreases in body weight gain, clinical signs,
and changes in organ weights). Also qualitatively, there is an
indication of increased sensitivity in the 2-generation reproduction
study in the rat in that offspring effects (decreased fetal, neonatal
and litter viability) were observed at a dose level where there was
less severe maternal toxicity (decreased body weight, body weight gain
and food consumption).
In male rats, trifluralin was associated with increased incidence
of thyroid follicular cell combined adenoma, papillary adenoma,
cystadenoma, and carcinoma tumors. Based on the available data,
trifluralin has been classified as a possible human carcinogen.
Extensive testing showed, however, that trifluralin is neither
mutagenic nor genotoxic, and does not inhibit the polymerization of
microtubules in mammalian cells. It is also not a neurotoxicant and
does not appear to be an immunotoxicant.
Specific information on the studies received and the nature of the
adverse effects caused by trifluralin 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 titled ``Trifluralin: Human Health
Risk Assessment for the Establishment of Tolerances on Oilseed Crop
Group 20'' pages 43-55 in docket ID number EPA-HQ-OPP-2012-0304.
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://www.epa.gov/pesticides/factsheets/riskassess.htm.
A summary of the toxicological endpoints for trifluralin used for
human risk assessment is shown in the following Table.
Table 1--Summary of Toxicological Doses and Endpoints for Trifluralin for Use in Human Health Risk Assessment
Point of Departure
Exposure/Scenario and uncertainty/ RfD, PAD, LOC for Study and toxicological effects
safety factors risk assessment
Acute dietary (Females 13-49 NOAEL = 100 mg/kg/ Acute RfD = 1.0 mg/ Developmental Toxicity Study Rat.
years of age). day. kg/day. LOAEL = 500 mg/kg/day, based on
UFA = 10x........... aPAD = 1.0 mg/kg/ reduced ossification of the
UFH = 10x........... day. vertebrae and ribs; thickened,
FQPA SF = 1x........ wavy or bent ribs; and increased
total litter resorptions.
Acute dietary (General population No endpoints identified from the available developmental toxicity studies
including infants and children). (rat and rabbit) were appropriate for an acute dietary assessment for
trifluralin in the general population, including infants and children.
Chronic dietary (All populations) NOAEL= 2.4 mg/kg/day Chronic RfD = 0.024 Chronic (capsule) Toxicity--Dog.
UFA = 10x........... mg/kg/day. LOAEL = 40 mg/kg/day, based on
UFH = 10x........... cPAD = 0.024 mg/kg/ increased frequency of abnormal
FQPA SF = 1x........ day. stool, decreased body weights and
body weight gains, and decreased
erythrocytes and hemoglobin and
increased thrombocytes (males).
Incidental oral short-term (1 to NOAEL= 10 mg/kg/day. LOC for MOE = 100.. 2-generation Reproduction Study in
30 days). UFA = 10x........... Rats.
UFH = 10x........... LOAEL = 32.5 mg/kg/day, based on
FQPA SF = 1x........ decreased pup weights in both
generations and increased
relative to body liver weights in
the F2b females.
Inhalation short-term (1 to 30 Inhalation study LOC for MOE = 100.. 30-Day Inhalation Study--Rat.
days). NOAEL = 300 mg/kg/ LOAEL = 1000 mg/m\3\ (270 mg/kg/
day (inhalation day), based on increased
absorption rate = methemoglobin and bilirubin in
100%). females and the incidence of
UFA = 10x........... dyspnea and rufflerd fur in males
UFH = 10x........... and females.
FQPA SF = 1x........
Cancer (Oral, dermal, inhalation) Classification: Possible Human Carcinogen Q1 \*\ = 2.96 x 10-3 (mg/kg/day)-1
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).
C. Exposure Assessment
1. Dietary exposure from food and feed uses. In evaluating dietary
exposure to trifluralin, EPA considered exposure under the petitioned-
for tolerances as well as all existing trifluralin tolerances in 40 CFR
180.207. EPA assessed dietary exposures from trifluralin in food as
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 trifluralin. In estimating acute
dietary exposure, EPA used 2003-2008 food consumption data from the
U.S. Department of Agriculture's (USDA's) National Health and Nutrition
Examination Survey, What We Eat in America, (NHANES/WWEIA). As to
residue levels in food, EPA conducted an unrefined assessment using
tolerance level residues, 100 percent crop treated (PCT), and default
Dietary Exposure Evaluation Model (DEEM) processing factors.
ii. Chronic exposure. In conducting the chronic dietary exposure
assessment EPA used 2003-2008 food consumption data from the USDA's
NHANES/WWEIA. As to residue levels in food, the chronic dietary
exposure and risk estimates are somewhat refined and assumed tolerance
level residues, PCT data for some existing uses, and DEEM default
processing factors. Pesticide Data Program (PDP) monitoring data were
used for carrot, orange, orange juice, pepper, potato, and tomato.
iii. Cancer. EPA determines whether quantitative cancer exposure
and risk assessments are appropriate for a food-use pesticide based on
the weight of the evidence from cancer studies and other relevant data.
If quantitative cancer risk assessment is appropriate, cancer risk may
be quantified using a linear or nonlinear approach. If sufficient
information on the carcinogenic mode of action is available, a
threshold or nonlinear approach is used and a cancer RfD is calculated
based on an earlier noncancer key event. If carcinogenic mode of action
data are not available, or if the mode of action data determines a
mutagenic mode of action, a default linear cancer slope factor approach
is utilized. Based on the data summarized in Unit III.A., EPA has
concluded that trifluralin should be classified as a possible human
carcinogen and a linear approach has been used to quantify cancer risk
since no mode of action data are available.
The aggregate cancer risk assessment for the general U.S.
population takes into account exposure estimates from dietary
consumption of trifluralin from food, residential and drinking water
sources. Exposures from residential uses are based on the lifetime
average daily dose and assume an exposure period of 5 days per year and
50 years of exposure in a lifetime. Dietary exposure assumptions were
quantified using the same estimates as discussed in Unit III.C.1.ii.,
iv. Anticipated residue and PCT information. Section 408(b)(2)(E)
of FFDCA authorizes EPA to use available data and information on the
anticipated residue levels of pesticide residues in food and the actual
levels of pesticide residues that have been measured in food. If EPA
relies on such information, EPA must require pursuant to FFDCA section
408(f)(1) that data be provided 5 years after the tolerance is
established, modified, or left in effect, demonstrating that the levels
in food are not above the levels anticipated. For the present action,
EPA will issue such data call-ins as are required by FFDCA section
408(b)(2)(E) and authorized under FFDCA section 408(f)(1). Data will be
required to be submitted no later than 5 years from the date of
issuance of these tolerances.
Section 408(b)(2)(F) of FFDCA states that the Agency may use data
on the actual percent of food treated for assessing chronic dietary
risk only if:
Condition a: The data used are reliable and provide a
valid basis to show what percentage of the food derived from such crop
is likely to contain the pesticide residue.
Condition b: The exposure estimate does not underestimate
exposure for any significant subpopulation group.
Condition c: Data are available on pesticide use and food
consumption in a particular area, the exposure estimate does not
understate exposure for the population in such area.
In addition, the Agency must provide for periodic evaluation of any
estimates used. To provide for the periodic evaluation of the estimate
of PCT as required by FFDCA section 408(b)(2)(F), EPA may require
registrants to submit data on PCT.
The Agency estimated the average PCT for existing uses as follows:
Almonds: 1%; asparagus: 20%; barley: 1%; green bean: 25%; broccoli:
10%; cabbage: 40%; canola: 2.5%; cantaloupe: 25%; carrot: 40%;
cauliflower: 10%; celery: 2.5%; corn: 1%; cotton: 30%; cucumber: 2.5%;
dry bean/pea: 10%; garlic: 5%; grapefruit: 1%; grape: 2.5%; honeydew:
20%; lemon: 1%; onion: 2.5%; orange: 1%; peach: 1%; peanut: 5%; pecan:
1%; pepper: 25%; pistachio: 2.5%; potato: 2.5%; pumpkin: 5%; sorghum:
1%; soybean: 5%; squash: 5%; sugarbeet: 2.5%; sugarcane: 5%; sunflower:
10%; tomato: 60%; walnut: 1%; watermelon: 10%; and wheat: 1%.
In most cases, EPA uses available data from United States
Department of Agriculture/National Agricultural Statistics Service
(USDA/NASS), proprietary market surveys, and the National Pesticide Use
Database for the chemical/crop combination for the most recent 6-7
years. EPA uses an average PCT for chronic dietary risk analysis. The
average PCT figure for each existing use is derived by combining
available public and private market survey data for that use, averaging
across all observations, and rounding to the nearest 5%, except for
those situations in which the average PCT is less than one. In those
cases, 1% is used as the average PCT and 2.5% is used as the maximum
PCT. EPA uses a maximum PCT for acute dietary risk analysis. The
maximum PCT figure is the highest observed maximum value reported
within the recent 6 years of available public and private market survey
data for the existing use and rounded up to the nearest multiple of 5%.
The Agency believes that the three conditions discussed in Unit
III.C.1.iv. have been met. With respect to Condition a, PCT estimates
are derived from Federal and private market survey data, which are
reliable and have a valid basis. The Agency is reasonably certain that
the percentage of the food treated is not likely to be an
underestimation. As to Conditions b and c, regional consumption
information and consumption information for significant subpopulations
is taken into account through EPA's computer-based model for evaluating
the exposure of significant subpopulations including several regional
groups. Use of this consumption information in EPA's risk assessment
process ensures that EPA's exposure estimate does not understate
exposure for any significant subpopulation group and allows the Agency
to be reasonably certain that no regional population is exposed to
residue levels higher than those estimated by the Agency. Other than
the data available through national food consumption surveys, EPA does
not have available reliable information on the regional consumption of
food to which trifluralin may be applied in a particular area.
2. Dietary exposure from drinking water. The Agency used screening
level water exposure models in the dietary exposure analysis and risk
assessment for trifluralin in drinking water. These simulation models
take into account data on the physical, chemical, and fate/transport
characteristics of trifluralin. Further information regarding EPA
drinking water models used in pesticide exposure assessment can be
found at http://www.epa.gov/oppefed1/models/water/index.htm.
Based on the Pesticide Root Zone Model/Exposure Analysis Modeling
System (PRZM/EXAMS) and Screening Concentration in Ground Water (SCI-
GROW) models, the estimated drinking water concentrations (EDWCs) of
trifluralin and its major degradates TR-4 ([alpha],[alpha],[alpha]-
trifluoro-5-nitro-N4,N4-dipropyl-toluene-3,4-diamine), TR-6 (5-
trifluoromethyl-3-nitro-1,2-benzenediamine) and TR-15 (2-ethyl-7-nitro-
5-(trifluoromethyl) benzimidazole) (the residues of concern in drinking
water) for acute exposures are estimated to be 23.83 parts per billion
(ppb) for surface water and 0.0275 ppb for ground water. For chronic
exposures for non-cancer assessments they are estimated to be 1.97 ppb
for surface water and 0.0275 ppb for ground water. And for cancer
assessments are estimated to be 1.59 ppb for surface water and 0.0275
ppb for ground water.
Modeled estimates of drinking water concentrations were directly
entered into the dietary exposure model. For acute dietary risk
assessment, the water concentration value of 23.83 ppb was used to
assess the contribution to drinking water. For chronic dietary risk
assessment, the water concentration of value 1.97 ppb was used to
assess the contribution to drinking water. And for cancer dietary risk
assessment, the water concentration of value 1.59 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).
Trifluralin is currently registered for the following uses that
could result in residential exposures including vegetable gardens,
turf, and ornamentals. EPA assessed residential exposure using the
following assumptions: EPA evaluated residential handler inhalation
exposures, which are considered short-term in duration. The handler
assessment did not consider dermal exposures because a dermal endpoint
was not identified; in three dermal toxicity studies (21/28 days in
rabbits; 21/28 days in rats; and 31-days in rats), trifluralin was
tested up to the limit dose (1000 mg/kg/day) and caused no systemic
toxicity. Handler exposure scenarios evaluated include the following:
Loading/applying granulars with a push-type spreader;
loading/applying granulars using a spoon, measuring scoop,
shaker can, or via hand;
mixing/loading/applying liquids with a hose-end sprayer;
mixing/loading/applying liquids with low pressure handwand
mixing/loading/applying liquids with backpack sprayer; and
applying trifluralin impregnated fabric squares to soil.
In terms of cancer risk, the Agency considers all exposure to
trifluralin, including the dermal and inhalation exposure expected for
homeowners, to have an associated carcinogenic risk. Carcinogenic risk
for homeowner applicators was assessed based on the application methods
outlined above. An upper-end assumption was made that the users
assessed will apply trifluralin each season, as labeled, with an
assumed exposure period of 5 days per year for 50 years of their life.
Specific methods (or scenarios) of application (spreader, sprayer,
etc.) were assessed to demonstrate the full range of exposure due to
method and area treated, although users are not expected to use one
method for 50 years. Carcinogenic risk for homeowner applicators was
assessed by combining dermal exposure (adjusted for an estimated 3%
absorption based on ethalfluralin data) and inhalation exposure (100%
absorption), calculating this exposure on a per day basis (``Lifetime
Average Daily Dose'', in mg/kg/day), and then quantifying risk by
multiplying the updated upper-bound carcinogenic potency factor
(Q1*) of 2.96 x 10-3 (mg/kg/day)-1 by
the combined exposure estimate.
There is the potential for post-application exposure for
individuals exposed as a result of being in an environment (vegetable
garden, golf course turf, turf) that has been previously treated with
trifluralin. All residential exposures are considered to be short-term
in duration (1-30 days). No acute dietary or short-term dermal points
of departure have been selected for trifluralin; therefore; only
incidental oral post-application non-cancer risk estimates for children
1<2 years old were evaluated. This lifestage is not the only lifestage
that could be potentially exposed for these post-application scenarios;
however, the assessment of this lifestage is health protective for the
exposures and risk estimates for any other potentially exposed
lifestage. Non-cancer post-application scenarios assessed are as
follows: Incidental oral (hand to mouth, object to mouth, and soil
ingestion) exposure from granular applications to turf.
Estimated post-application cancer risk for the general U.S.
population includes infants and children; therefore, in accordance with
Agency policy, a children's cancer risk estimate was not reported
separately. For post-application cancer risk, the only adult post-
application residential scenarios that are applicable are the
Dermal exposure to residues on lawns
Dermal exposure to golf course turf
Dermal exposure in home vegetable gardens.
There may be post-application residential exposure scenarios for
trifluralin which could be combined for purposes of an aggregate
exposure assessment. Combinations for residential exposure scenarios
should have a reasonable probability of occurring on a single day and
the pest that an individual is attempting to
control must be considered. It is reasonable that an adult may treat
their turf and garden on the same day.
The worst case residential exposure for use in the adult non-cancer
aggregate assessment reflects residential handler inhalation exposure
from applying granules by hand to pre-plant ornamentals.
The worst case residential exposure for use in the children 1<2
years old non-cancer aggregate assessment reflects hand-to-mouth short-
term post-application exposures from granular application to
And lastly, the worst case residential exposure for use in the
cancer aggregate assessment reflects dermal and inhalation exposure
from loading/applying granules with a belly grinder to pre-plant
Further information regarding EPA standard assumptions and generic
inputs for residential exposures may be found at http://www.epa.gov/pesticides/trac/science/trac6a05.pdf.
4. Cumulative effects from substances with a common mechanism of
toxicity. Section 408(b)(2)(D)(v) of FFDCA requires that, when
considering whether to establish, modify, or revoke a tolerance, the
Agency consider ``available information'' concerning the cumulative
effects of a particular pesticide's residues and ``other substances
that have a common mechanism of toxicity.''
EPA has not found trifluralin to share a common mechanism of
toxicity with any other substances, and trifluralin does not appear to
produce a toxic metabolite produced by other substances. For the
purposes of this tolerance action, therefore, EPA has assumed that
trifluralin 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.
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
2. Prenatal and postnatal sensitivity. There was qualitative
evidence of increased susceptibility in the rat developmental toxicity
study, where fetal developmental effects (increased resorptions and
wavy ribs) occurred in the presence of less severe maternal effects
(decreases in body weight gain, clinical signs, and changes in organ
weights). Also qualitatively, there is an indication of increased
sensitivity in the 2-generation reproduction study in the rat in that
offspring effects (decreased fetal, neonatal and litter viability) were
observed at a dose level where there was less severe maternal toxicity
(decreased body weight, body weight gain and food consumption).
3. Conclusion. EPA has determined that the safety of infants and
children would be adequately protected if the FQPA SF were reduced to
1X. This determination is based on the following findings:
i. The toxicity database for trifluralin is complete except for
immunotoxicity testing. In the absence of specific immunotoxicity
studies, EPA has evaluated the available trifluralin toxicity data to
determine whether an additional uncertainty factor is needed to account
or potential immunotoxicity. There are no indications in the available
studies that organs associated with immune function, such as the
thymus, are affected by trifluralin and trifluralin does not belong to
a class of chemicals (e.g., the organotins, heavy metals, or
halogenated aromatic hydrocarbons) that would be expected to be
immunotoxic. Based on the above considerations in this unit, EPA does
not believe that conducting the immunotoxicity study will result in a
dose less than the point of departure already used in this risk
assessment, and an additional database uncertainty factor (UF) for
potential immunotoxicity does not need to be applied.
ii. There is no indication that trifluralin is a neurotoxic
chemical and there is no need for a developmental neurotoxicity study
or additional UFs to account for neurotoxicity.
iii. Although qualitative evidence of increased susceptibility was
seen in the rat developmental toxicity study, and an indication of
increased sensitivity in the 2-generation reproduction study in the rat
in that offspring effects, the concern for these effects is low for the
following reasons: (1) The dose response was well characterized; (2)
the developmental effects were seen in the presence of maternal
toxicity; (3) clear NOAELs/LOAELs were established for maternal and
developmental toxicities; and (4) for the rats in the 2-generation
reproduction study, the effects were seen at a high-dose level (295
milligrams/kilogram/day (mg/kg/day) for males and 337 mg/kg/day for
females). Furthermore, offspring viability was not adversely affected
in the two other 2-generation studies with trifluralin at dose levels
up to 100 and 148 mg/kg/day. Finally, there are no residual
uncertainties for pre-natal and post-natal toxicity since the doses
selected for overall risk assessment are protective of the effects seen
in these studies.
iv. There are no residual uncertainties identified in the exposure
databases. The acute dietary food exposure assessment for females 13-
49, the population identified as having potential acute exposure, was
performed based on 100 PCT and tolerance-level residues. The chronic
dietary exposure and risk estimates are somewhat refined and assumed
tolerance level residues, some PCT data, and DEEM default processing
factors. Pesticide Data Program (PDP) monitoring data were used for
carrot, orange, orange juice, pepper, potato, and tomato. These
refinements are based on reliable data and will not underestimate the
exposure and risk to any population subgroups. EPA made conservative
(protective) assumptions in the ground and surface water modeling used
to assess exposure to trifluralin in drinking water. EPA used similarly
conservative assumptions to assess post-application incidental oral
exposure of toddlers. These assessments will not underestimate the
exposure and risks posed by trifluralin.
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 population adjusted dose (aPAD) and chronic population adjusted
dose (cPAD). For linear cancer risks, EPA calculates the lifetime
probability of acquiring cancer given the estimated aggregate exposure.
Short-, intermediate-term, 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 trifluralin will occupy less than 1% of the aPAD for females 13-49
the only population subgroup of concern.
2. Chronic risk. Using the exposure assumptions described in this
unit for chronic exposure, EPA has concluded that chronic exposure to
trifluralin from food and water will utilize less than 1% of the cPAD
for all population groups. Based on the explanation in Unit III.C.3.,
regarding residential use patterns, chronic residential exposure to
residues of trifluralin is not expected.
3. Short-term risk. Short-term aggregate exposure takes into
account short-term residential exposure plus chronic exposure to food
and water (considered to be a background exposure level).
Trifluralin is currently registered for uses that could result in
short-term residential exposure, and the Agency has determined that it
is appropriate to aggregate chronic exposure through food and water
with short-term residential exposures to trifluralin.
Using the exposure assumptions described in this unit for short-
term exposures, EPA has concluded the combined short-term food, water,
and residential exposures result in aggregate MOEs of 25,000 for adults
and 26,000 for children. Because EPA's level of concern for trifluralin
is a MOE of 100 or below, these MOEs are not of concern.
4. Intermediate-term risk. Intermediate-term aggregate exposure
takes into account intermediate-term residential exposure plus chronic
exposure to food and water (considered to be a background exposure
An intermediate-term adverse effect was identified; however,
trifluralin is not registered for any use patterns that would result in
intermediate-term residential exposure. Intermediate-term risk is
assessed based on intermediate-term residential exposure plus chronic
dietary exposure. Because there is no intermediate-term residential
exposure and chronic dietary exposure has already been assessed under
the appropriately protective cPAD (which is at least as protective as
the POD used to assess intermediate-term risk), no further assessment
of intermediate-term risk is necessary, and EPA relies on the chronic
dietary risk assessment for evaluating intermediate-term risk for
5. Aggregate cancer risk for U.S. population. The aggregate cancer
risk estimate from trifluralin residues in food, drinking water, and
residential exposure is 1 x 10-6. EPA generally considers
cancer risks (expressed as the probability of an increased cancer case)
in the range of 1 in 1 million (or 1 x 10-6) or less to be
6. Determination of safety. Based on these risk assessments, EPA
concludes that there is a reasonable certainty that no harm will result
to the general population or to infants and children from aggregate
exposure to trifluralin residues.
IV. Other Considerations
A. Analytical Enforcement Methodology
Adequate enforcement methodology (gas chromatography (GC) with
electron capture detection (ECD)) is available to enforce the tolerance
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:
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 trifluralin for the crops
addressed in this document.
C. Revisions to Petitioned-For Tolerances
PA has revised the tolerance expression to clarify (1) that, as
provided in FFDCA section 408(a)(3), the tolerance covers metabolites
and degradates of trifluralin not specifically mentioned; and (2) that
compliance with the specified tolerance levels is to be determined by
measuring only the specific compounds mentioned in the tolerance
Therefore, tolerances are established for residues of trifluralin,
including its metabolites and degradates, in or on oilseed, crop group
20 at 0.05 ppm. Compliance with the tolerance level is to be determined
by only trifluralin [alpha],[alpha],[alpha]-trifluoro-2,6-dinitro-N,N-
dipropyl-p-toluidine, in or on the oilseed, crop group 20.
Also, due to the establishment of the tolerance on oilseed, crop
group 20, the existing tolerances for rapeseed, seed; flax, seed;
mustard, seed; sunflower, seed; safflower, seed; and cotton undelinted
seed are removed as unnecessary.
VI. Statutory and Executive Order Reviews
This final rule establishes tolerances under FFDCA section 408(d)
in response to a petition submitted to the Agency. The Office of
Management and Budget (OMB) has exempted these types of actions from
review under Executive Order 12866, entitled ``Regulatory Planning and
Review'' (58 FR 51735, October 4, 1993). Because this final rule has
been exempted from review under Executive Order 12866, this final rule
is not subject to Executive Order 13211, entitled ``Actions Concerning
Regulations That Significantly Affect Energy Supply, Distribution, or
Use'' (66 FR 28355, May 22, 2001) or Executive Order 13045, entitled
``Protection of Children From Environmental Health Risks and Safety
Risks'' (62 FR 19885, April 23, 1997). This final rule does not contain
any information collections subject to OMB approval under the Paperwork
Reduction Act (PRA) (44 U.S.C. 3501 et seq.), nor does it require any
special considerations under Executive Order 12898, entitled ``Federal
Actions To Address Environmental Justice in Minority Populations and
Low-Income Populations'' (59 FR 7629, February 16, 1994).
Since tolerances and exemptions that are established on the basis
of a petition under FFDCA section 408(d), such as the tolerance in this
final rule, do not require the issuance of a proposed rule, the
requirements of the Regulatory Flexibility Act (RFA) (5 U.S.C. 601 et
seq.), do not apply.
This final rule directly regulates growers, food processors, food
handlers, and food retailers, not States or tribes, nor does this
action alter the relationships or distribution of power and
responsibilities established by Congress in the preemption provisions
of FFDCA section 408(n)(4). As such, the Agency has determined that
this action will not have a substantial direct effect on States or
tribal governments, on the relationship between the national government
and the States or tribal governments, or on the distribution of power
and responsibilities among the various levels of government or between
the Federal Government and Indian tribes. Thus, the Agency has
determined that Executive Order 13132, entitled ``Federalism'' (64 FR
43255, August 10, 1999) and Executive Order 13175, entitled
``Consultation and Coordination With Indian Tribal Governments'' (65 FR
67249, November 9, 2000) do not apply to this final rule. In addition,
this final rule does not impose any enforceable duty or contain any
unfunded mandate as described under Title II of the Unfunded Mandates
Reform Act of 1995 (UMRA) (2 U.S.C. 1501 et seq.).
This action does not involve any technical standards that would
require Agency consideration of voluntary consensus standards pursuant
to section 12(d) of the National Technology Transfer and Advancement
Act of 1995 (NTTAA) (15 U.S.C. 272 note).
VII. Congressional Review Act
Pursuant to the Congressional Review Act (5 U.S.C. 801 et seq.),
EPA will submit a report containing this rule and other required
information to the U.S. Senate, the U.S. House of Representatives, and
the Comptroller General of the United States prior to publication of
the rule in the Federal Register. This action is not a ``major rule''
as defined by 5 U.S.C. 804(2).
List of Subjects in 40 CFR Part 180
Environmental protection, Administrative practice and procedure,
Agricultural commodities, Pesticides and pests, Reporting and
Dated: July 25, 2013.
Director, Registration Division, Office of Pesticide Programs.
Therefore, 40 CFR chapter I is amended as follows:
1. The authority citation for part 180 continues to read as follows:
Authority: 21 U.S.C. 321(q), 346a and 371.
2. In Sec. 180.207:
a. Revise the introductory text of paragraph (a).
b. Remove the commodities cotton undelinted seed; flax, seed; mustard,
seed; rapeseed, seed; safflower, seed; and sunflower, seed in the table
in paragraph (a).
c. Add alphabetically the following commodity to the table in paragraph
The amendment read as follows:
Sec. 180.207 Trifluralin; tolerances for residues.
(a) General. Tolerances are established for residues of
trifluralin, including its metabolites and degradates, in or on the
commodities in the following table. Compliance with the tolerance
levels specified in the following table is to be determined by only
p-toluidine, in or on the commodity.
* * * * *
Oilseed, crop group 20...................................... 0.05
* * * * *
* * * * *
[FR Doc. 2013-18420 Filed 7-30-13; 8:45 am]
BILLING CODE 6560-50-P