[Federal Register Volume 79, Number 186 (Thursday, September 25, 2014)]
[Rules and Regulations]
[Pages 57450-57458]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2014-22833]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
[EPA-HQ-OPP-2013-0268; FRL-9915-78]
Thiabendazole; Pesticide Tolerances
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
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SUMMARY: This regulation establishes tolerances for residues of
thiabendazole in or on multiple commodities which are identified and
discussed later in this document. Syngenta Crop Protection, LLC.,
requested these tolerances under the Federal Food, Drug, and Cosmetic
Act (FFDCA).
DATES: This regulation is effective September 25, 2014. Objections and
requests for hearings must be received on or before November 24, 2014,
and must be filed in accordance with the instructions provided in 40
CFR part 178 (see also Unit I.C. of the SUPPLEMENTARY INFORMATION).
ADDRESSES: The docket for this action, identified by docket
identification (ID) number EPA-HQ-OPP-2013-0268, is available at http://www.regulations.gov or at the Office of Pesticide Programs
[[Page 57451]]
Regulatory Public Docket (OPP Docket) in the Environmental Protection
Agency Docket Center (EPA/DC), West William Jefferson Clinton Bldg.,
Rm. 3334, 1301 Constitution Ave. NW., Washington, DC 20460-0001. The
Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through
Friday, excluding legal holidays. The telephone number for the Public
Reading Room is (202) 566-1744, and the telephone number for the OPP
Docket is (703) 305-5805. Please review the visitor instructions and
additional information about the docket available at http://www.epa.gov/dockets.
FOR FURTHER INFORMATION CONTACT: Lois Rossi, Registration Division
(7505P), Office of Pesticide Programs, Environmental Protection Agency,
1200 Pennsylvania Ave. NW., Washington, DC 20460-0001; main telephone
number: (703) 305-7090; email address: [email protected].
SUPPLEMENTARY INFORMATION:
I. General Information
A. Does this action apply to me?
You may be potentially affected by this action if you are an
agricultural producer, food manufacturer, or pesticide manufacturer.
The following list of North American Industrial Classification System
(NAICS) codes is not intended to be exhaustive, but rather provides a
guide to help readers determine whether this document applies to them.
Potentially affected entities may include:
Crop production (NAICS code 111).
Animal production (NAICS code 112).
Food manufacturing (NAICS code 311).
Pesticide manufacturing (NAICS code 32532).
B. How can I get electronic access to other related information?
You may access a frequently updated electronic version of EPA's
tolerance regulations at 40 CFR part 180 through the Government
Printing Office's e-CFR site at http://www.ecfr.gov/cgi-bin/text-idx?&c=ecfr&tpl=/ecfrbrowse/Title40/40tab_02.tpl.
C. How can I file an objection or hearing request?
Under FFDCA section 408(g), 21 U.S.C. 346a, any person may file an
objection to any aspect of this regulation and may also request a
hearing on those objections. You must file your objection or request a
hearing on this regulation in accordance with the instructions provided
in 40 CFR part 178. To ensure proper receipt by EPA, you must identify
docket ID number EPA-HQ-OPP-2013-0268 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
November 24, 2014. Addresses for mail and hand delivery of objections
and hearing requests are provided in 40 CFR 178.25(b).
In addition to filing an objection or hearing request with the
Hearing Clerk as described in 40 CFR part 178, please submit a copy of
the filing (excluding any Confidential Business Information (CBI)) for
inclusion in the public docket. Information not marked confidential
pursuant to 40 CFR part 2 may be disclosed publicly by EPA without
prior notice. Submit the non-CBI copy of your objection or hearing
request, identified by docket ID number EPA-HQ-OPP-2013-0268, by one of
the following methods:
Federal eRulemaking Portal: http://www.regulations.gov.
Follow the online instructions for submitting comments. Do not submit
electronically any information you consider to be CBI or other
information whose disclosure is restricted by statute.
Mail: OPP Docket, Environmental Protection Agency Docket
Center (EPA/DC), (28221T), 1200 Pennsylvania Ave. NW., Washington, DC
20460-0001.
Hand Delivery: To make special arrangements for hand
delivery or delivery of boxed information, please follow the
instructions at http://www.epa.gov/dockets/contacts.html. Additional
instructions on commenting or visiting the docket, along with more
information about dockets generally, is available at http://www.epa.gov/dockets.
II. Summary of Petitioned-For Tolerance
In the Federal Register of August 1, 2014 (79 FR 44729) (FRL-9911-
67), 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
3F8166) by Syngenta Crop Protection, LLC, P.O. Box 18300, Greensboro,
NC 27419-8300. The petition requested that 40 CFR 180.242 be amended by
establishing tolerances for residues of the fungicide thiabendazole (2-
(4-thiazolyl)benzimidazole) and its metabolite benzimidazole, in or on
vegetable, root (except sugar beet), subgroup 1B at 0.02 ppm; radish,
tops at 0.02 ppm; onion, bulb, subgroup 3-07A at 0.02 ppm; Brassica,
head and stem, subgroup 5-A at 0.02 ppm; vegetable, cucurbit group 9 at
0.02 ppm; barley, grain at 0.05 ppm; barley, hay at 0.30 ppm; barley,
straw at 0.30 ppm; wheat, grain at 0.05 ppm; wheat, straw at 0.30 ppm;
wheat, hay at 0.30 ppm; wheat, forage 0.30 ppm; oats, grain at 0.05
ppm; oats, hay at 0.30 ppm; oats, straw at 0.30 ppm; oats, forage at
0.30 ppm; rye, grain at 0.05 ppm; rye, straw at 0.30 ppm; rye, forage
at 0.30 ppm; triticale, grain at 0.05 ppm; triticale, hay at 0.30 ppm;
triticale, straw at 0.30 ppm; triticale, forage at 0.30 ppm; alfalfa,
forage at 0.02 ppm; alfalfa, hay at 0.02 ppm; and spinach at 0.02 ppm.
That document referenced a summary of the petition prepared by Syngenta
Crop Protection, the registrant, which is available in the docket,
http://www.regulations.gov. There were no comments received in response
to the notice of filing.
The Notice of Filing (NOF) published on August 1, 2014 (79 FR
44729) supersedes an earlier NOF for the same petition for
thiabendazole that was issued in the Federal Register of June 5, 2013
(78 FR 33785) (FRL-9386-2).
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 thiabendazole including
exposure resulting from the tolerances established by this action.
EPA's assessment of exposures and risks associated with thiabendazole
follows.
[[Page 57452]]
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 thyroid and liver (centrilobular hypertrophy) are the primary
target organs of thiabendazole toxicity. Thiabendazole produced a
treatment-related increase in absolute and relative liver weights in
both sexes in a chronic dog study. Other treatment related effects
reported were histopathological changes in kidneys (hyperplasia of
transitional epithelium, tubular degeneration) and spleen (congested
and pigmented) in rats. Additional toxic effects observed in these
studies included decreases in body weight and/or food consumption. The
available database indicates that thiabendazole is not neurotoxic. In
an acute neurotoxicity rat study (ACN), decreases in the Functional
Observation Battery (FOB) (reduced body temperature in males, reduced
rearing in females, and reduced locomotor activity in males and females
at time of peak effect (approximately 3 hours post-dose) were seen
without morphological or histopathological effects on the brain.
Thiabendazole was not neurotoxic in rats in a subchronic neurotoxicity
study. In a 21-day dermal toxicity study in rats, no systemic or dermal
effects were seen at the limit dose (1,000 milligram/kilogram/day (mg/
kg/day)). In prenatal developmental toxicity studies in rats, rabbits,
and mice and in the 2-generation reproduction study in rats, effects in
the fetuses or neonates occurred at or above doses that caused maternal
or parental toxicity.
In the adult animal, effects on the thyroid following thiabendazole
exposure were observed at a dose lower than the neurotoxicity dose
observed in the ACN. There are no thiabendazole data with which to
determine whether this is also the case in the fetus/postnatal animal.
Based on a weight of evidence (WOE) approach considering all the
available hazard and exposure information for thiabendazole, the Agency
concluded that a developmental thyroid toxicity study is required since
there is clear evidence of thyroid toxicity in adult animals and thus a
concern for potential toxicity during pregnancy, infancy and childhood.
The developmental thyroid toxicity study will better address this
concern than a developmental neurotoxicity study.
In an immunotoxicity study, thiabendazole produced significant
decreased spleen activity at the highest dose tested (5,000 ppm
equivalent to 1,027 mg/kg/day) which also produced significant
increased liver weight.
The genetic toxicology studies on thiabendazole indicate that it is
not genotoxic in in vivo and in vitro assays. Review of literature
studies indicated that thiabendazole has weak aneugenic activity in
both somatic and germinal cells. In a chronic rat study, thiabendazole
induced thyroid tumors in males only. Thiabendazole did not induce
tumors in mice. Thiabendazole has been classified by the Agency as
``likely to be carcinogenic at doses high enough to cause a disturbance
of the thyroid hormonal balance but not likely to be carcinogenic at
doses lower than those which could cause a disturbance of this hormonal
balance.'' Taking into account all of this information, the Agency has
determined that quantification of risk using a non-linear approach
(i.e., chronic population adjusted dose (cPAD)) will adequately account
for all chronic toxicity, including carcinogenicity that could result
from exposure to thiabendazole.
Specific information on the studies received and the nature of the
adverse effects caused by thiabendazole 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 ``Thiabendazole: Human
Health Risk Assessment for the Requested Increase in the Currently
Registered Seed Treatment Use Rate on Soybeans and the New Section 3
Uses of Thiabendazole for Seed Treatment on Assorted Vegetables and
Small Grains Including: Vegetable, Root (Except Sugar Beet), Subgroup
1B; Radish Tops; Onion, Bulb, Subgroup 3-07A; Brassica, Head and Stem,
Subgroup 5A; Vegetable, Cucurbit Group 9; Alfalfa; Spinach; and a
Number of Small Grains (Barley, Oats, Rye, and Triticale)'' on pages
45-53 in docket ID number EPA-HQ-OPP-2013-0268.
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 (LOC) to use in evaluating the risk posed by human exposure to
the pesticide. For hazards that have a threshold below which there is
no appreciable risk, the toxicological POD is used as the basis for
derivation of reference values for risk assessment. PODs are developed
based on a careful analysis of the doses in each toxicological study to
determine the dose at which 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 thiabendazole used for
human risk assessment is shown in the following table of this unit.
[[Page 57453]]
Table--Summary of Toxicological Doses and Endpoints for Thiabendazole for Use in Human Health Risk Assessment
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Point of departure
Exposure/Scenario and uncertainty/ RfD, PAD, LOC for Study and toxicological effects
safety factors risk assessment
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Acute dietary (general population NOAEL = 50 mg/kg/day Acute RfD = 0.05 mg/ Acute neurotoxicity study.
including females 13-49 years of UFA = 10x........... kg/day. LOAEL = 200 mg/kg based decreases
age and children). UFH = 10x........... aPAD = 0.05 mg/kg/ in the FOB (reduced body
FQPA SF = UFDB 10x.. day. temperature in males, and reduced
rearing in females, reduced
locomotor activity in males and
females, at time of peak effect
(approximately 3 hours post-
dose). Reduced body weight gain
and food consumption occurred on
day 1.
Chronic dietary (all populations) NOAEL= 10 mg/kg/day. Chronic RfD = 0.033 2-year chronic carcinogenicity in
UFA = 3x............ mg/kg/day. the rat.
UFH = 10x........... cPAD = 0.033 mg/kg/ Chronic LOAEL = 30 mg/kg/day based
FQPA SF = UFDB 10x.. day. on decreased body weight gains
and liver hypertrophy.
Thiabendazole induced thyroid
adenomas in male rats at dosages
of >=30 mg/kg/day. Supported by
subchronic toxicity rat study.
Subchronic LOAEL = 40 mg/kg/based
on reduced body weight and body
weight gains and
histopathological changes in the
bone marrow (erythroid
hyperplasia), liver
(centrilobular hypertrophy),
thyroid (follicular cell
hypertrophy) and spleen
(pigmented).
Incidental oral short-term (1 to NOAEL= 10 mg/kg/day. LOC for MOE = 300.. Subchronic oral toxicity study--
30 days) and intermediate-term UFA = 3x............ rat.
(1 to 6 months). UFH = 10x........... LOAEL = 40 mg/kg/day based on
FQPA SF = 10x UFDB.. reduced body weight gains and
histopathological changes in the
bone marrow, liver and thyroid.
Dermal short-term (1 to 30 days) Dermal (or oral) LOC for MOE = 300.. Subchronic oral toxicity study--
and intermediate-term (1 to 6 study. rat.
months). NOAEL = 10 mg/kg/day LOAEL = 40 mg/kg/day based on
(dermal absorption reduced body weight gains and
rate = 0.5%. histopathological changes in the
UFA = 3x............ bone marrow, liver and thyroid.
UFH = 10x...........
FQPA SF = 10x UFDB..
Inhalation short-term (1 to 30 NOAEL= 10 mg/kg/day. LOC for MOE = 300.. Subchronic oral toxicity study--
days) and intermediate-term (1 UFA = 3x............ rat.
to 6 months). UFH = 10x........... LOAEL = 40 mg/kg/day based on
FQPA SF = 10x UFDB.. reduced body weight gains and
histopathological changes in the
bone marrow, liver and thyroid.
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Cancer (oral, dermal, inhalation) Likely to be carcinogenic at doses high enough to cause a disturbance of the
thyroid hormonal balance but not likely to be carcinogenic at doses lower
that those which could cause a disturbance of this hormonal balance.
Quantification of risk using a non-linear approach (i.e., cPAD) will
adequately account for all chronic toxicity, including carcinogenicity that
could result from exposure to thiabendazole.
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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). UFDB = to account for the absence of data or other
data deficiency. 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 thiabendazole, EPA considered exposure under the
petitioned-for tolerances as well as all existing thiabendazole
tolerances in 40 CFR 180.242. EPA assessed dietary exposures from
thiabendazole in food as follows:
i. Acute exposure. Quantitative acute dietary exposure and risk
assessments are performed for a food-use pesticide, if a toxicological
study has indicated the possibility of an effect of concern occurring
as a result of a 1-day or single exposure.
Such effects were identified for thiabendazole. In estimating acute
dietary exposure, EPA used 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 used a refined acute probabilistic dietary
exposure assessment for thiabendazole using both anticipated residue
estimates based on USDA Pesticide Data Program (PDP) monitoring data
and percent crop treated (PCT) information for soybean and wheat and
assumed 100 PCT for all other commodities.
ii. Chronic exposure. In conducting the chronic dietary exposure
assessment EPA used food consumption data from the USDA NHANES/WWEIA.
As to residue levels in food, EPA used a refined chronic probabilistic
dietary exposure assessment for thiabendazole using both anticipated
residue estimates based on USDA PDP monitoring data and PCT information
for soybean and wheat and assumed 100 PCT for all other commodities.
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.
Cancer risk is 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
[[Page 57454]]
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 a nonlinear RfD approach is appropriate
for assessing cancer risk to thiabendazole. Cancer risk was assessed
using the same exposure 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 PCT for existing uses as follows:
Acute dietary risk assessment: soybeans 2.5%; wheat 2.5%.
Chronic dietary risk assessment: soybeans 1%; 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 thiabendazole 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 thiabendazole in drinking water. These simulation models
take into account data on the physical, chemical, and fate/transport
characteristics of thiabendazole. 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 FQPA Index Reservoir Screening Tool (FIRST) and
Pesticide Root Zone Model Ground Water (PRZM GW), the estimated
drinking water concentrations (EDWCs) of thiabendazole for acute
exposures are estimated to be 3.80 parts per billion (ppb) for surface
water and 0.62 ppb for ground water and for chronic exposures are
estimated to be 0.47 ppb for surface 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 3.80 ppb was used to
assess the contribution to drinking water. For chronic dietary risk
assessment, the water concentration of value 0.47 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). Thiabendazole is
currently registered for use as antimicrobial ingredient in paint,
sponges, carpet backing, canvas textiles, wallboard and ceiling tiles,
polyurethane foam, plastics and rubber, paper, and coatings and filters
used in HVAC systems. There are two antimicrobial exposure scenarios
that were assessed for residential exposures: Treated paint and
impregnated sponges. The other antimicrobial uses of thiabendazole
(carpet backing, canvas textiles, wallboard and ceiling tiles,
polyurethane foam, plastics and rubber, paper, and coatings and filters
used in HVAC systems) are not expected to cause exposure in residential
settings because there is no direct contact to the treated articles,
the vapor pressure of thiabendazole is very low, and the unlikelihood
that the treated plastics and rubbers would be used in toys.
EPA assessed residential exposure to treated paint and impregnated
sponges using the following assumptions: For treated paint, residential
short-term dermal and inhalation exposure to residential handlers using
brush/roller application and airless sprayer application; for the
impregnated sponge use, short- and intermediate-term incidental oral
exposure. Thiabendazole treated sponges are limited to 600 ppm
thiabendazole on a sponge. Various residue amounts may be transferred
from the sponge to food contact surfaces, such as countertops and
utensils/glassware, and then to food and subsequently ingested. An
assessment was conducted for incidental oral exposure assuming that
100% of the thiabendazole on a treated sponge is transferred to
surfaces over 20 days and that each 20 days the user would use a new
sponge (5% released per day). This assumption is considered
conservative because (1) sponges will generally be used much longer
than 20 days; (2) it is
[[Page 57455]]
unlikely that 100% of the thiabendazole would be released from the
sponge in such a short period; and (3) it is very unlikely that 100% of
any released thiabendazole would be transferred to countertops because
this assumption does not account any thiabendazole that is washed down
the sink or that normally degrades. 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 thiabendazole to share a common mechanism of
toxicity with any other substances, and thiabendazole does not appear
to produce a toxic metabolite produced by other substances. For the
purposes of this tolerance action, therefore, EPA has assumed that
thiabendazole 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
factor.
2. Prenatal and postnatal sensitivity. No evidence of increased
quantitative or qualitative susceptibility was seen following in utero
exposure to thiabendazole with rats or rabbits in the prenatal
developmental studies or in young rats in the 2-generation reproduction
study. There is no evidence for neurotoxicity following oral exposures
to thiabendazole. Thyroid toxicity was seen following subchronic and
chronic exposures to adult rats in multiple studies. There is, however,
no data regarding the potential effects of thiabendazole on thyroid
homeostasis in the young animals. This lack of characterization creates
uncertainty with regards to potential life stage sensitivities due to
exposure to thiabendazole. Therefore, the Agency is requiring a
developmental thyroid assay in rats with thiabendazole. This study will
better address the concern for potential thyroid toxicity in the young.
Although the Agency is asking for the developmental thyroid study, EPA
does not expect it to result in a lower point of departure than what
the Agency is regulating from and therefore the 10X is protective.
There are no residual uncertainties in the thiabendazole residue
database with regards to dietary or occupational exposure. Therefore,
the FQPA SF is retained at 10X in the form of a database uncertainty
factor (UFDB). For the acute dietary endpoint the total UF
is 1,000 (an interspecies scaling factor of 10X, an intraspecies
variability factor of 10X, a FQPA database uncertainty factor of 10X
for lack of a developmental thyroid study). For the remaining
endpoints, the combined total UF is 300 (an interspecies scaling factor
of 3X, lowered from 10X for toxicodynamic reasons (rats eliminate
thyroxine (a thyroid hormone) at a higher rate than humans), an
intraspecies variability factor of 10X, an FQPA database uncertainty
factor of 10X for lack of a developmental thyroid study was applied).
3. Conclusion. EPA has determined that reliable data show the
safety of infants and children would be adequately protected if the
FQPA SF is retained at 10X in the form of a database uncertainty factor
(UFDB). That decision is based on the following findings:
i. The toxicology database for thiabendazole is complete with the
exception of a developmental thyroid toxicity study. Based on a WOE
approach considering all the available hazard and exposure information
for thiabendazole, the Agency concluded that a developmental thyroid
toxicity study is required since there is clear evidence of thyroid
toxicity in adult animals and thus a concern for potential toxicity
during pregnancy, infancy and childhood. The developmental thyroid
toxicity study will better address this concern than a developmental
neurotoxicity study. Acceptable studies are available for
developmental, reproduction, chronic, subchronic, subchronic
neurotoxicity and immunotoxicity.
ii. There is no indication that thiabendazole is a neurotoxic
chemical and there is no need for a developmental neurotoxicity study
or additional UFs to account for neurotoxicity.
iii. The data submitted to the Agency, as well as those from
published literature, demonstrate no increased susceptibility in rats,
rabbits, or mice to in utero and/or early postnatal exposure to
thiabendazole. In the prenatal developmental toxicity studies in rats,
rabbits, and mice and in the 2-generations reproduction study in rats,
developmental effects in the fetuses or neonates occurred at or above
doses that caused maternal or parental toxicity. A developmental
neurotoxicity study with thiabendazole was deemed not required by the
Agency.
There is evidence of thyroid toxicity following subchronic and
chronic exposures to rats characterized as histopathological changes in
the thyroid in multiple studies in rats. Disruption of thyroid
homeostasis is the initial, critical effect that may lead to adverse
effects on the developing nervous system. Thus, as noted above, a
developmental thyroid study is required.
iv. There are no residual uncertainties in the exposure database.
The dietary risk assessment is conservative and will not underestimate
dietary and/or non-dietary occupational exposure to thiabendazole. The
acute and chronic dietary assessments conducted with the Dietary
Exposure Evaluation Model software with the Food Commodity Intake
Database (DEEM-FCID) were refined analyses. The assessments utilized
anticipated residues, default processing factors, and available percent
crop treated data. The DEEM analysis also used Tier 1 drinking water
estimates. For these reasons it can be concluded that the DEEM-FCID
analysis does not underestimate risk from acute or chronic exposure to
thiabendazole. Similarly, EPA does not believe that the non-dietary
occupational exposures are underestimated because they are also based
on conservative assumptions, including maximum application rates, and
standard values for unit exposures and acreage treated/amount handled.
These assessments will not underestimate the exposure and risks posed
by thiabendazole.
E. Aggregate Risks and Determination of Safety
EPA determines whether acute and chronic dietary pesticide
exposures are
[[Page 57456]]
safe by comparing aggregate exposure estimates to the acute PAD (aPAD)
and chronic PAD (cPAD). For linear cancer risks, EPA calculates the
lifetime probability of acquiring cancer given the estimated aggregate
exposure. Short-, intermediate-, and chronic-term risks are evaluated
by comparing the estimated aggregate food, water, and residential
exposure to the appropriate PODs to ensure that an adequate MOE exists.
1. Acute risk. Using the exposure assumptions discussed in this
unit for acute exposure, the acute dietary exposure from food and water
to thiabendazole will occupy 69% of the aPAD for children 1-2 years
old, the population group receiving the greatest exposure.
2. Chronic risk. Using the exposure assumptions described in this
unit for chronic exposure, EPA has concluded that chronic exposure to
thiabendazole from food and water will utilize 4.7% of the cPAD for
children 1-2 years old, the population group receiving the greatest
exposure. Based on the explanation in Unit III.C.3., regarding
residential use patterns, chronic residential exposure to residues of
thiabendazole is not expected.
3. Short- and intermediate-term risk. Short- and intermediate-term
aggregate exposure takes into account short- and intermediate-term
residential exposure plus chronic exposure to food and water
(considered to be a background exposure level).
Thiabendazole is currently registered for uses that could result in
short- and intermediate-term residential exposure, and the Agency has
determined that it is appropriate to aggregate chronic exposure through
food and water with short- and intermediate-term residential exposures
to thiabendazole.
Using the exposure assumptions described in this unit for short-
and intermediate-term exposures, EPA has concluded the combined short-
and intermediate-term food, water, and residential exposures result in
aggregate MOEs from the paint use of 2,000 for all population subgroups
and aggregate MOEs from the sponge use of 1,400 for children 1-2 years
old and 7,300 for the general population. Because EPA's level of
concern for thiabendazole is a MOE of 300 or below, these MOEs are not
of concern.
4. Aggregate cancer risk for U.S. population. Since thiabendazole
is classified as likely to be carcinogenic at doses high enough to
cause a disturbance of the thyroid hormonal balance but not likely to
be carcinogenic at doses lower than those which could cause a
disturbance of this hormonal balance, a cancer dietary exposure
assessment is not required. EPA is currently regulating chronic dietary
risk with a chronic RfD that reflects a dose level below dose levels at
which thyroid hormone balance is impacted and consequently is also
being protective of potential carcinogenic effects.
5. Determination of safety. Based on these risk assessments, EPA
concludes that there is a reasonable certainty that no harm will result
to the general population, or to infants and children from aggregate
exposure to thiabendazole residues.
IV. Other Considerations
A. Analytical Enforcement Methodology
Acceptable enforcement analytical methods are available for
thiabendazole and benzimidazole in plant commodities. Four
spectrophotofluorometric methods for the determination of thiabendazole
are published in the Pesticide Analytical Manual (PAM) Vol. II, and a
high performance liquid chromatography (HPLC) method with fluorescence
detection (FLD) for the determination of benzimidazole (free and
conjugated) is identified in the U.S. EPA Index of Residue Analytical
Methods under thiabendazole as Study No. 93020.
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:
[email protected].
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 thiabendazole on any of the
commodities cited in this document.
C. Revisions to Petitioned-For Tolerances
Finally, EPA has revised the tolerance expression to clarify (1)
that, as provided in FFDCA section 408(a)(3), the tolerance covers
metabolites and degradates of thiabendazole 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 expression.
V. Conclusion
Therefore, tolerances are established for residues of
thiabendazole, [2-(4-thiazolyl) benzimidazole] and its metabolite
benzimidazole (free and conjugated), in or on alfalfa, forage at 0.02
ppm; alfalfa, hay at 0.02 ppm; barley, grain at 0.05 ppm; barley, hay
at 0.30 ppm; barley, straw at 0.30 ppm; Brassica, head and stem,
subgroup 5A at 0.02 ppm; oat, forage at 0.30 ppm; oat, grain at 0.05
ppm; oat, hay at 0.30 ppm; oat, straw at 0.30 ppm; onion, bulb,
subgroup 3-07A at 0.02 ppm; radish, tops at 0.02 ppm; rye, forage at
0.30 ppm; rye, grain at 0.05 ppm; rye, straw at 0.30 ppm; spinach at
0.02 ppm; triticale, forage at 0.30 ppm; triticale, grain at 0.05 ppm;
triticale, hay at 0.30 ppm; triticale, straw at 0.30 ppm; vegetable,
cucurbit, group 9 at 0.02 ppm; vegetable, root (except sugarbeet),
subgroup 1B at 0.02 ppm; wheat, forage at 0.30 ppm; and wheat, hay at
0.30 ppm. In addition, the following existing tolerances are modified:
wheat, grain from 1.0 ppm to 0.05 ppm; and wheat straw from 1.0 ppm to
0.30 ppm.
Also, the time-limited tolerances for beet, sugar, dried pulp;
beet, sugar, roots; and beet, sugar, tops, are removed because they
expired on 12/25/10.
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
[[Page 57457]]
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
recordkeeping requirements.
Dated: September 18, 2014.
Lois Rossi,
Director, Registration 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. In Sec. 180.242, revise paragraph (a)(1) and the introductory text
of paragraph (a)(2) to read as follows:
Sec. 180.242 Thiabendazole; tolerances for residues.
(a) General. (1) Tolerances are established for residues of
thiabendazole, including its metabolites and degradates, in or on the
commodities in the table below. Compliance with the tolerance levels
specified below is to be determined by measuring only the sum of
thiabendazole (2-(4-thiazolyl)benzimidazole) and its metabolite
benzimidazole (free and conjugated), calculated as the stoichiometric
equivalent of thiabendazole, in or on the commodity.
------------------------------------------------------------------------
Parts per
Commodity million
------------------------------------------------------------------------
Alfalfa, forage......................................... 0.02
Alfalfa, hay............................................ 0.02
Apple, wet pomace....................................... 12.0
Avocado \1\............................................. 10.0
Banana, postharvest..................................... 3.0
Barley, grain........................................... 0.05
Barley, hay............................................. 0.30
Barley, straw........................................... 0.30
Bean, dry, seed......................................... 0.1
Brassica, head and stem, subgroup 5A.................... 0.02
Cantaloupe \1\.......................................... 15.0
Carrot, roots, postharvest.............................. 10.0
Citrus, oil............................................. 15.0
Corn, field, forage..................................... 0.01
Corn, field, grain...................................... 0.01
Corn, field, stover..................................... 0.01
Corn, pop, forage....................................... 0.01
Corn, pop, grain........................................ 0.01
Corn, pop, stover....................................... 0.01
Corn, sweet, forage..................................... 0.01
Corn, sweet, kernels plus cop with husks removed........ 0.01
Corn, sweet, stover..................................... 0.01
Fruit, citrus, group 10, postharvest.................... 10.0
Fruit, pome, group 11, postharvest...................... 5.0
Mango................................................... 10.0
Mushroom................................................ 40.0
Oats, forage............................................ 0.30
Oats, grain............................................. 0.05
Oats, hay............................................... 0.30
Oats, straw............................................. 0.30
Onion, bulb, subgroup 3-07A............................. 0.02
Papaya, postharvest..................................... 5.0
[[Page 57458]]
Potato, postharvest..................................... 10.0
Radish, tops............................................ 0.02
Rye, forage............................................. 0.30
Rye, grain.............................................. 0.05
Rye, straw.............................................. 0.30
Soybean................................................. 0.1
Spinach................................................. 0.02
Strawberry \1\.......................................... 5.0
Sweet potato (postharvest to sweet potato intended only 0.05
for use as seed).......................................
Triticale, forage....................................... 0.30
Triticale, grain........................................ 0.05
Triticale, hay.......................................... 0.30
Triticale, straw........................................ 0.30
Vegetable, cucurbit, group 9............................ 0.02
Vegetable, root (except sugarbeet), subgroup 1B......... 0.02
Wheat, forage........................................... 0.30
Wheat, grain............................................ 0.05
Wheat, hay.............................................. 0.30
Wheat, straw............................................ 0.30
------------------------------------------------------------------------
\1\There are no U.S. registrations on the indicated commodity.
(2) Tolerances are established for residues of thiabendazole,
including its metabolites and degradates, in or on the commodities in
the table below. Compliance with the tolerance levels specified below
is to be determined by measuring only the sum of thiabendazole (2-(4-
thiazolyl)benzimidazole) and its metabolites 5-hydroxythiabendazole
(free and conjugated) and benzimidazole (free and conjugated),
calculated as the stoichiometric equivalent of thiabendazole, in or on
the commodity.
* * * * *
[FR Doc. 2014-22833 Filed 9-24-14; 8:45 am]
BILLING CODE 6560-50-P