[Federal Register Volume 73, Number 181 (Wednesday, September 17, 2008)]
[Rules and Regulations]
[Pages 53725-53732]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E8-21589]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
[EPA-HQ-OPP-2007-0894; FRL-8382-6]
Ethoprop; Pesticide Tolerances
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
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SUMMARY: This regulation establishes tolerances for residues of
ethoprop in or on hop, dried cones; peppermint, tops; and spearmint,
tops. Interregional Research Project Number 4 (IR-4) requested these
tolerances under the Federal Food, Drug, and Cosmetic Act (FFDCA).
DATES: This regulation is effective September 17, 2008. Objections and
requests for hearings must be received on or before November 17, 2008,
and must be filed in accordance with the instructions provided in 40
CFR part 178 (see also Unit I.C. of the SUPPLEMENTARY INFORMATION).
ADDRESSES: EPA has established a docket for this action under docket
identification (ID) number EPA-HQ-OPP-2007-0894. All documents in the
docket are listed in the docket index available at http://www.regulations.gov. Although listed in the index, some information is
not publicly available, e.g., Confidential Business Information (CBI)
or other information whose disclosure is restricted by statute. Certain
other material, such as copyrighted material, is not placed on the
Internet and will be publicly available only in hard copy form.
Publicly available docket materials are available in the electronic
docket at http://www.regulations.gov, or, if only available in hard
copy, at the OPP Regulatory Public Docket in Rm. S-4400, One Potomac
Yard (South Bldg.), 2777 S. Crystal Dr., Arlington, VA. The Docket
Facility is open from 8:30 a.m. to 4 p.m., Monday through Friday,
excluding legal holidays. The Docket Facility telephone number is (703)
305-5805.
FOR FURTHER INFORMATION CONTACT: Susan Stanton, Registration Division
(7505P), Office of Pesticide Programs, Environmental Protection Agency,
1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone
number: (703) 305-5218; e-mail 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.
Potentially affected entities may include, but are not limited to those
engaged in the following activities:
Crop production (NAICS code 111).
Animal production (NAICS code 112).
Food manufacturing (NAICS code 311).
Pesticide manufacturing (NAICS code 32532).
This listing is not intended to be exhaustive, but rather to
provide a guide for readers regarding entities likely to be affected by
this action. Other types of entities not listed in this unit could also
be affected. The North American Industrial Classification System
(NAICS) codes have been provided to assist you and others in
determining whether this action might apply to certain entities. If you
have any questions regarding the applicability of this action to a
particular entity, consult the person listed under FOR FURTHER
INFORMATION CONTACT.
B. How Can I Access Electronic Copies of this Document?
In addition to accessing electronically available documents at
http://www.regulations.gov, you may access this Federal Register
document electronically through the EPA Internet under the ``Federal
Register'' listings at http://www.epa.gov/fedrgstr. You may also access
a frequently updated electronic version of EPA's tolerance regulations
at 40 CFR part 180 through the Government Printing Office's pilot e-CFR
site at http://www.gpoaccess.gov/ecfr.
C. Can I File an Objection or Hearing Request?
Under section 408(g) of FFDCA, 21 U.S.C. 346a, any person may file
an objection to any aspect of this regulation and may also request a
hearing on those objections. 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
[[Page 53726]]
identify docket ID number EPA-HQ-OPP-2007-0894 in the subject line on
the first page of your submission. All requests must be in writing, and
must be mailed or delivered to the Hearing Clerk as required by 40 CFR
part 178 on or before November 17, 2008.
In addition to filing an objection or hearing request with the
Hearing Clerk as described in 40 CFR part 178, please submit a copy of
the filing that does not contain any CBI for inclusion in the public
docket that is described in ADDRESSES. Information not marked
confidential pursuant to 40 CFR part 2 may be disclosed publicly by EPA
without prior notice. Submit this copy, identified by docket ID number
EPA-HQ-OPP-2007-0894, by one of the following methods:
Federal eRulemaking Portal: http://www.regulations.gov.
Follow the on-line instructions for submitting comments.
Mail: Office of Pesticide Programs (OPP) Regulatory Public
Docket (7502P), Environmental Protection Agency, 1200 Pennsylvania
Ave., NW., Washington, DC 20460-0001.
Delivery: OPP Regulatory Public Docket (7502P),
Environmental Protection Agency, Rm. S-4400, One Potomac Yard (South
Bldg.), 2777 S. Crystal Dr., Arlington, VA. Deliveries are only
accepted during the Docket Facility's normal hours of operation (8:30
a.m. to 4 p.m., Monday through Friday, excluding legal holidays).
Special arrangements should be made for deliveries of boxed
information. The Docket Facility telephone number is (703) 305-5805.
II. Petition for Tolerance
In the Federal Register of September 28, 2007 (72 FR 55204) (FRL-
8147-1), EPA issued a notice pursuant to section 408(d)(3) of FFDCA, 21
U.S.C. 346a(d)(3), announcing the filing of pesticide petitions (PP
5E4491 and PP 7E7247) by Interregional Research Project Number 4 (IR-
4), 500 College Road East, Suite 201, Princeton, NJ 08540. The
petitions requested that 40 CFR 180.262 be amended by establishing
tolerances for residues of the insecticide and nematicide, ethoprop, O-
ethyl S,S-dipropyl phosphorodithioate, in or on hop, dried cone
(PP7E7247) and mint, hay (PP 5E4491) at 0.02 parts per million (ppm).
That notice referenced a summary of the petitions prepared by Bayer
CropScience, the registrant, on behalf of IR-4, which is available to
the public in the docket, http://www.regulations.gov. There were no
comments received in response to the notice of filing.
IR-4 proposed a tolerance on the commodity ``mint, hay'' at 0.02
ppm. EPA has determined that separate tolerances at 0.02 ppm should be
established on the commodities ``spearmint, tops'' and ``peppermint,
tops'' instead of the single tolerance on ``mint, hay'' to agree with
the preferred commodity terms in the Agency's Food and Feed Commodity
Vocabulary. EPA has also modified the commodity term ``hop, dried
cone'' slightly to read ``hop, dried cones'' to agree with the Food and
Feed Commodity Vocabulary.
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 section 408(b)(2)(D) of FFDCA, and the factors
specified in section 408(b)(2)(D) of FFDCA, EPA has reviewed the
available scientific data and other relevant information in support of
this action. EPA has sufficient data to assess the hazards of and to
make a determination on aggregate exposure for the petitioned-for
tolerances for residues of ethoprop on hop, dried cones; peppermint,
tops; and spearmint, tops at 0.02 ppm. EPA's assessment of exposures
and risks associated with establishing tolerances follows.
A. Toxicological Profile
EPA has evaluated the available toxicity data and considered its
validity, completeness, and reliability as well as the relationship of
the results of the studies to human risk. EPA has also considered
available information concerning the variability of the sensitivities
of major identifiable subgroups of consumers, including infants and
children.
The toxic mode of action of ethoprop in insects and humans is by
phosphorylation of the acetylcholinesterase (referred to as
cholinesterase or ChE in this document) enzyme in the brain and
peripheral nervous systems. The resulting enzyme inhibition causes
accumulation of the neurotransmitter, acetylcholine, and resulting
signs of neurotoxicity.
Ethoprop is acutely toxic by both oral and dermal routes. In the
longer term studies, the most sensitive indication of toxicity was
inhibition of brain and red blood cell (RBC) ChE. Signs of
neurotoxicity related to inhibition of ChE by ethoprop include tremors,
ataxia, muscle fasiculations, lacrimation, salivation, rapid/shallow
respiration, repetitive chewing movements, nasal and perianal stains,
vocalization, aggressive behavior, decreased grip strength, and
decreased motor activity. A slight anemia and liver toxicity (elevated
liver enzymes and microscopic liver lesions) were also noted in dog
studies.
Ethoprop is classified ``likely to be carcinogenic to humans''
based on malignant adrenal pheochromocytomas in male rats and is
regulated by EPA using the linear low dose extrapolation approach with
a potency factor (Q1*) of 2.81 x 10-2 milligrams/
kilogram/day (mg/kg/day)-1.
No developmental toxicity was noted in rat and rabbit developmental
studies. In the rat developmental toxicity study, maternal toxicity
included decreased body weight gain and increased incidence of soft
stool, the latter effect attributed to ChE inhibition. No maternal
toxicity occurred in the rabbit developmental study. Despite the
absence of toxicity in this study, dosing was considered adequate,
since the highest dose was close to the lethal dose determined in the
range-finding developmental rabbit study. Ethoprop did not affect
reproductive parameters in the 2-generation reproduction toxicity study
in rats. Pup mortality in this study occurred at a high dietary
concentration and was accompanied by significant maternal toxicity
(clinical signs of tremors and loose stool and brain ChE inhibition).
In the developmental neurotoxicity (DNT) study, an effect on
learning in the water maze test was noted in high-dose males. Motor
activity in all male treatment groups was increased on postnatal day 17
due to a lack of habituation (i.e., there was little or no decrease in
activity over the course of the test session). There was no indication
of increased fetal or offspring sensitivity to ChE inhibition in this
study.
The relative sensitivities of adult rats and 11-day old rat pups to
ChE
[[Page 53727]]
inhibition were compared in acute and 11-day comparative cholinesterase
studies. Pups were 8 times as sensitive as adults for brain ChE
inhibition in the acute study and were 12 times as sensitive as adults
in the 11-day study. Pup sensitivity is believed to be due to their
immature metabolic capacity.
Specific information on the studies received and the nature of the
adverse effects caused by ethoprop, 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 Ethoprop Human Health Risk
Assessment of New Uses on Hops and Mint at page 47 in docket ID number
EPA-HQ-OPP-2007-0894.
B. Toxicological Endpoints
For hazards that have a threshold below which there is no
appreciable risk, a toxicological point of departure (POD) is
identified as the basis for derivation of reference values for risk
assessment. The POD may be defined as the highest dose at which no
adverse effects are observed (the NOAEL) in the toxicology study
identified as appropriate for use in risk assessment. However, if a
NOAEL cannot be determined, the lowest dose at which adverse effects of
concern are identified (the LOAEL) or a Benchmark Dose (BMD) approach
is sometimes used for risk assessment. Uncertainty/safety factors (UFs)
are used in conjunction with the POD to take into account uncertainties
inherent in the extrapolation from laboratory animal data to humans and
in the variations in sensitivity among members of the human population
as well as other unknowns. Safety is assessed for acute and chronic
dietary risks by comparing aggregate food and water exposure to the
pesticide to the acute population adjusted dose (aPAD) and chronic
population adjusted dose (cPAD). The aPAD and cPAD are calculated by
dividing the POD by all applicable UFs. Aggregate short-term,
intermediate-term, and chronic-term risks are evaluated by comparing
food, water, and residential exposure to the POD to ensure that the
margin of exposure (MOE) called for by the product of all applicable
UFs is not exceeded. This latter value is referred to as the Level of
Concern (LOC).
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
greater than that 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 ethoprop used for
human risk assessment can be found at http://www.regulations.gov in the
document Ethoprop Human Health Risk Assessment of New Uses on Hops and
Mint at page 20 in docket ID number EPA-HQ-OPP-2007-0894.
C. Exposure Assessment
1. Dietary exposure from food and feed uses. In evaluating dietary
exposure to ethoprop, EPA considered exposure under the petitioned-for
tolerances as well as all existing ethoprop tolerances in 40 CFR
180.262, except peanuts. Although tolerances for peanuts and peanut hay
have been established, there have been no active registrations for use
of ethoprop on peanuts since April, 2002, and the Agency proposed to
revoke the peanut tolerances in the Federal Register of June 4, 2008
(73 FR 31788) (FRL-8363-9). For these reasons, peanuts were not
considered in the dietary assessment.
The residues of concern for acute and chronic dietary risk
assessment include parent ethoprop and the metabolites S-ME, O-ethyl-S-
methyl-S-propylphosphorodithioate, and O-ME, O-ethyl-O-methyl-S-
propylphosphorothioate. For cancer dietary risk, the residues of
concern are parent and the metabolites S-ME-, O-ME and M-1, O-ethyl-S-
propyl phosphorodithioate. Since the available field trial and
monitoring data do not include information on the metabolites,
metabolite ratios derived from metabolism and rotational crop studies
were used to estimate metabolite levels in ethoprop-treated
commodities. Further information on the development of the metabolite
ratios can be found at http://www.regulations.gov in the document
Ethoprop. Anticipated Residues to Support New Uses on Hops and Mint in
docket ID number EPA-HQ-OPP-2007-0894. EPA assessed dietary exposures
from the combined residues of ethoprop and its metabolites of concern
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.
In estimating acute dietary exposure, EPA used food consumption
information from the United States Department of Agriculture (USDA)
1994-1996 and 1998 Nationwide Continuing Surveys of Food Intakes by
Individuals (CSFII). As to residue levels in food, EPA relied on
anticipated residues derived from field trials or monitoring data from
USDA's Pesticide Data Program (PDP) for most commodities. PDP data were
used to develop anticipated residues for bananas, snap beans (fresh and
canned), corn syrup, cucumber, pineapple, potato and sweet potato.
Field trial data were used for field corn, sweet corn, sugarcane and
cabbage. EPA assumed tolerance-level residues for lima beans and the
new commodities, hops and mint. Acute dietary exposure estimates were
further refined using maximum percent crop treated (PCT) estimates for
snap beans, cabbage, sweet corn, field corn, cucumber, potatoes,
sugarcane and sweet potato. EPA assumed 100 PCT for bananas, lima
beans, pineapple, hops and mint.
ii. Chronic exposure. In conducting the chronic dietary exposure
assessment EPA used the food consumption data from the USDA 1994-1996
and 1998 CSFII. As to residue levels in food, EPA relied on anticipated
residues derived from field trials or PDP monitoring data for the same
commodities specified above under ``Acute exposure.'' Again, EPA
assumed tolerance-level residues for lima beans, hops and mint. Chronic
dietary exposure estimates were further refined using average percent
crop treated (PCT) estimates for snap beans, cabbage, sweet corn, field
corn, cucumber, potatoes, sugarcane and sweet potato. EPA assumed 100
PCT for bananas, lima beans, pineapple, hops and mint.
iii. Cancer. Cancer risk was assessed using the linear low dose
extrapolation approach with a potency factor (Q1*) of 2.81 x
10-2 (mg/kg/day)-1 . In conducting the cancer
dietary exposure assessment EPA used the food consumption data from the
USDA 1994-1996 and 1998 CSFII and the same field trial/PDP monitoring
data and PCT data used in the chronic assessment. Different metabolite
ratios were used, since the metabolites of concern for cancer risk
differ from the metabolites of concern for chronic risk.
iv. Anticipated residue and percent crop treated (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
[[Page 53728]]
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 used PCT information as follows:
Acute dietary exposure assessment: Snap beans 5%; cabbage 5%; sweet
corn 5%; field corn 2.5%; cucumber 5%; potatoes 5%; sugarcane 5%; and
sweet potato 15%.
Chronic and cancer dietary exposure assessments: Snap beans 5%;
cabbage 5%; sweet corn 1%; field corn 1%; cucumber 1%; potatoes 5%;
sugarcane 5%; and sweet potato 15%.
In most cases, EPA uses available data from the 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 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 ethoprop may be applied in a particular area.
2. Dietary exposure from drinking water. Concerns about the
potential for ethoprop or its metabolites to reach water used for
drinking water at levels of concern were identified in the ``Interim
Reregistration Eligibility Decision for Ethoprop'', published in
September, 2001 and available on the Office of Pesticide Programs' web
site at http://www.epa.gov/pesticides/reregistration/status.htm. EPA's
concerns were based on screening drinking water assessments conducted
using the Pesticide Root Zone Model/Exposure Analysis Modeling System
(PRZM/EXAMS) and Screening Concentration in Ground Water (SCI-GROW)
models, which indicated potential drinking water concentrations above
EPA's levels of concern for acute and cancer exposures. As a result of
these concerns, the registrant was required by the Agency to conduct
targeted monitoring surveys of presumed high vulnerability community
water supplies to determine concentrations of ethoprop that may occur
in ground water and surface water. The monitoring data required by EPA
have been submitted and reviewed and demonstrate considerably lower
water concentrations of ethoprop than the modeled values (by more than
2 orders of magnitude). Although the monitoring surveys do not reflect
the new uses on hops and mint, EPA does not expect the new uses to
contribute substantially to high-end ethoprop drinking water exposure,
since both of the proposed use sites are of minor acreage, and the
production regions do not correspond to the areas that were found to be
at greatest risk for drinking water exposure. Therefore, EPA believes
the monitoring survey results represent reasonable estimates of
ethoprop residues likely to occur in drinking water from all existing
and new uses. Although the highest measured values from the monitoring
surveys do not represent the peak concentrations that could occur in
drinking water, the theoretical peak is highly likely to be much closer
to the monitoring values than the modeled values, in part because the
usage intensity (i.e., pounds active ingredient per acre) assumed by
the model is 250 to 500 times the highest actual watershed-wide usage
intensity estimated in the monitoring study; and sales data recently
submitted by the registrant show that ethoprop usage has gradually
declined nationwide since the drinking water study was completed.
Therefore, the Agency relied on the monitoring survey data in assessing
drinking water exposures to ethoprop and its degradates of concern as
described below.
The sum of the highest concentrations of ethoprop and its drinking
water degradates of concern (S-ME; O-ME; O-HE, O-ethyl-S-
propylphosphorothioate; and SSDP, S,S-dipropylphosphorodithioate)
measured in the targeted monitoring surveys was 0.231 parts per billion
(ppb). This water concentration value was directly entered into the
dietary exposure model and used to assess acute, chronic and cancer
drinking water exposures to ethoprop. Recognizing that this value does
not represent the theoretical peak ethoprop drinking water
concentration, EPA conducted additional acute, chronic and cancer
dietary analyses using a drinking water concentration of 0.52 ppb,
equivalent to more than 2x the highest measured monitoring value. For
the drinking water exposure scenarios of greatest concern (acute and
cancer), EPA also conducted analyses using the highest drinking water
concentration that would result in aggregate risks below the level of
concern: 15 ppb (65x the highest monitoring value) for the acute
assessment and 5 ppb (22x the highest monitoring value) for the cancer
assessment.
EPA notes that the highest measured concentrations of ethoprop used
in the dietary assessment occurred in raw water and, therefore, do not
account for
[[Page 53729]]
any mitigation of exposure that might occur as a result of water
treatment. The registrant did analyze finished water on dates for which
raw water bore detectable residues, and the concentrations in finished
water were generally lower than those in raw water samples taken on the
same day.
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).
Ethoprop is not registered for any specific use patterns that would
result in residential exposure.
4. Cumulative effects from substances with a common mechanism of
toxicity. Section 408(b)(2)(D)(v) of FFDCA requires that, when
considering whether to establish, modify, or revoke a tolerance, the
Agency consider ``available information'' concerning the cumulative
effects of a particular pesticide's residues and ``other substances
that have a common mechanism of toxicity.'' The reason for
consideration of other substances is due to the possibility that low-
level exposures to multiple chemical substances that cause a common
toxic effect by a common mechanism could lead to the same adverse
health effect as would a higher level of exposure to any of the
substances individually. A person exposed to a pesticide at a level
that is considered safe may, in fact, experience harm if that person is
also exposed to other substances that cause a common toxic effect by a
mechanism common with that of the subject pesticide, even if the
individual exposure levels to the other substances are also considered
safe.
The organophosphate pesticides (OPs) were established as the first
common mechanism group by EPA in 1999, based on their shared ability to
bind to and phosphorylate the enzyme acetylcholinesterase in both the
central (brain) and peripheral nervous systems. Ethoprop is an OP
pesticide. In December 2001, the Agency issued the ``Preliminary OP
Cumulative Risk Assessment'', available at http://www.epa.gov/pesticides/cumulative/pra_op_methods.htm. In June 2002, the Agency
released its Revised OP CRA, available at http://www.epa.gov/pesticides/cumulative/rra-op/, which included the cumulative risk due
to the OPs from exposures in food, drinking water and residential uses.
In August 2006, the Agency issued an update to the 2002 Revised OP CRA
document, which emphasized changes, modifications and amendments. With
the 2006 update, available at http://www.epa.gov/pesticides/cumulative/2006-op/index.htm, the Agency has developed a highly refined and
complex cumulative risk assessment for the OPs that represents the
state of the science regarding existing hazard and exposure data and
the models and approaches used. Based upon the results from the 2006
update, the Agency concluded that the results of the OP cumulative risk
assessment support a reasonable certainty of no harm finding.
In both the 2002 revised OP CRA, as well as the 2006 update, the
cumulative dietary risk associated with the use of OP pesticides on
food crops was assessed using residue monitoring data collected by the
USDA Pesticide Data Program (PDP) and dietary consumption data
collected by USDA's CSFII. Both assessments relied primarily on the PDP
for residue data; the 2006 update added PDP data collected in 2002-2004
to the 1994-2001 data used in the 2002 Revised Assessment. The PDP has
been collecting pesticide residue data since 1991, primarily for
purposes of estimating dietary exposure. The program focuses on high-
consumption foods for children and reflects foods typically available
throughout the year. A complete description of the PDP and all data
through 2004 are available online at http://www.ams.usda.gov/science/pdp. No PDP data on mint or hops currently exist that could have been
used in a cumulative assessment. OP residues in hops and mint were not
included in the PDP database, in part because hops and mint are low-
consumption foods. A quantitative estimate of mint consumption over a
single day was obtained for the general U.S. population and
subpopulations using the Dietary Exposure Evaluation Model (DEEM-
FCID(TM), Version 2.03), which uses food consumption data
from the USDA's CSFII from 1994-1996 and 1998. The maximum consumption
estimate at the 99.9th percentile of exposure for all populations is
less than 0.1 grams mint/day. Hops are used when brewing beer, and
there can be relatively high consumption of beer in some population
groups. However, the relative amount of hops used in brewing beer, on a
weight basis, is low, so hops consumption is low as well.
EPA does not believe that inclusion of ethoprop residues in hops
and mint in the OP CRA will significantly modify the calculated risk.
First, hops and mint are low consumption foods, and, thus, even if hops
and mint contained quantifiable levels of OPs, it would be unlikely to
significantly alter the OP CRA. Secondly, residues of ethoprop in hops
and mint are non-detectable at the label application rate, based on
controlled crop field trials. Also, there is virtually no difference in
ethoprop exposure when hops and mint are excluded from the dietary
exposure assessment. If ethoprop exposure from hops and mint is
insignificant in comparison to exposure to ethoprop from other uses of
the chemical, it necessarily is insignificant in comparison to exposure
to the more than 30 other OPs. For these reasons, EPA concludes that
the establishment of ethoprop hops and mint tolerances will not raise a
concern regarding cumulative OP exposure.
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. The following acceptable
studies are available for assessing potential sensitivity of infants
and children to ethoprop: Rat and rabbit developmental toxicity
studies, a DNT study in rats, a 2-generation reproduction toxicity
study in rats, acute and subchronic neurotoxicity studies, an acute
comparative cholinesterase study in adult and rat pups, and an 11-day
comparative cholinesterase study in adult and rat pups. There was no
evidence of increased quantitative or qualitative susceptibility to
ethoprop of in utero rats or rabbits in the developmental toxicity
studies and no evidence of increased susceptibility of fetuses or
offspring in the DNT study. In the DNT study the NOAEL for brain ChE
activity in pups was the same as for adults and the NOAEL for RBC ChE
activity was greater in pups than for adults. Fetuses were less
sensitive to ChE inibition by ethoprop than were the adults.
Pup mortality in the 2-generation reproduction study occurred at a
high dietary concentration and was accompanied by significant maternal
toxicity (clinical signs of tremors and loose stool and brain ChE
inhibition).
[[Page 53730]]
The NOAEL for pup mortality was 13 mg/kg/day. Because the POD for
chronic dietary exposure (0.14 mg/kg/day) is much lower than the NOAEL
for pup mortality and is protective of this endpoint, there are no
residual concerns for sensitivity to infants and children from this
study.
In the acute comparative cholinesterase study, pups were eight
times as sensitive as adults for brain ChE inhibition. This study was
used to select a POD for acute dietary assessment. Because the POD is
protective of the population of concern, there are no residual concerns
from this study.
In the 11-day comparative cholinesterase study, pups were 12 times
as sensitive as adults for brain ChE inhibition. This study was used to
select a POD for chronic dietary assessment. Because the POD is
protective of the population of concern, there are no residual concerns
from this study.
3. Conclusion. EPA has determined that reliable data show the
safety of infants and children would be adequately protected if the
FQPA SF were reduced to 1X. That decision is based on the following
findings:
i. The toxicity database for ethoprop is complete, except for
immunotoxicity studies. EPA began requiring functional immunotoxicity
testing of all food and non-food use pesticides on December 26, 2007.
Since this requirement went into effect well after the tolerance
petitions were submitted, these studies are not yet available for
ethoprop. In the absence of specific immunotoxicity studies, EPA has
evaluated the available ethoprop toxicity data to determine whether an
additional database uncertainty factor is needed to account for
potential immunotoxicity. Ethoprop does not belong to a class of
chemicals that would be expected to be immunotoxic; however, there was
some indication of possible immunotoxicity in the form of decreased
white blood cell counts in high-dose males (4 mg/kg/day) in the mouse
carcinogenicity study. Since the dose at which this effect was seen is
nearly 30 times higher than the BMDL10 of 0.14 mg/kg/day already
established for ethoprop, and since there was no other evidence of
immunotoxicity in the ethoprop toxicity studies, EPA does not believe
that conducting immunotoxicity testing will result in a lower POD for
ethoprop, and an additional database uncertainty factor for ethoprop is
not needed to account for potential immunotoxicity.
ii. Ethoprop is a neurotoxic chemical. Although there is evidence
in the acute and 11-day comparative cholinesterase studies of increased
offspring senstivity to ChE inhibition by ethoprop, there are no
residual uncertainties with regard to these effects in infants and
children. The points of departure for acute and chronic dietary
assessment are based on brain ChE inhibition in pups in the comparative
cholinesterase studies. Benchmark dose (BMD) modeling was used to
select points of departure for dietary exposure. In comparison to other
toxicity studies, the comparative cholinesterase studies had much
closer dose spacing around the NOAEL and LOAEL doses and thus provided
an accurate determination of BMDL10 values (the lower 95% confidence
limit on the estimated mean brain ChE inhibition 10% effect level) used
to evaluate risk. Furthermore, since the comparative cholinesterase
studies provided an assessment of comparative sensitivity of adults and
offspring; and provided the lowest, most sensitive points of departure
for the most vulnerable population, the points of departure based on
these studies are protective of other toxic effects.
iii. There is no evidence that ethoprop results in increased
susceptibility in in utero rats or rabbits in the prenatal
developmental studies. Although there is some evidence of increased
qualitative susceptibility of offspring in the 2-generation
reproduction study (pup mortality vs. clinical signs of tremors, loose
stool and brain ChE inhibition in maternal animals), the Agency did not
identify any residual uncertainties after establishing toxicity
endpoints and traditional UFs to be used in the risk assessment.
iv. There are no residual uncertainties identified in the exposure
databases. The dietary food exposure assessments utilized anticipated
residues that are based on reliable field trial or monitoring data. For
most currently registered commodities, the dietary assessments also
utilized PCT data that have a valid basis and are considered to be
reliable. The drinking water exposure assessments utilized targeted
monitoring data from vulnerable community raw water supplies intended
to provide reasonably conservative (i.e., high-end) estimates of
drinking water concentrations. To account for the possibility of higher
drinking water concentrations than those measured in the monitoring
surveys, EPA utilized concentrations from 2x to 65x the highest
measured value in the dietary exposure assessments. Residential
exposure to ethoprop is not expected to occur. These assessments will
not underestimate the exposure and risks posed by ethoprop.
E. Aggregate Risks and Determination of Safety
EPA determines whether acute and chronic pesticide exposures are
safe by comparing aggregate exposure estimates to the aPAD and cPAD.
The aPAD and cPAD represent the highest safe exposures, taking into
account all appropriate SFs. EPA calculates the aPAD and cPAD by
dividing the POD by all applicable UFs. For linear cancer risks, EPA
calculates the probability of additional cancer cases 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 POD to ensure that the MOE called for
by the product of all applicable UFs is not exceeded.
1. Acute risk. An acute aggregate risk assessment takes into
account exposure estimates from acute dietary consumption of food and
drinking water. Using the food exposure assumptions discussed in this
unit for acute exposure and the highest measured concentrations of
ethoprop and its degradates from the targeted drinking water monitoring
surveys (0.231 ppb), the acute dietary exposure from food and water to
ethoprop will occupy 18% of the aPAD for infants less than 1 year old,
the population group receiving the greatest exposure. Using a drinking
water estimate for ethoprop and its degradates of 0.52 ppb, equivalent
to more than 2x the maximum measured value from monitoring data, acute
dietary exposure to ethoprop from food and water will occupy 19% of the
aPAD for infants less than 1 year old. These acute dietary risk
estimates are based on high-end exposures at the 99.9th percentile.
2. Chronic risk. Using the food exposure assumptions described in
this unit for chronic exposure and the highest measured concentrations
of ethoprop and its degradates from the targeted drinking water
monitoring surveys (0.231 ppb), EPA has concluded that chronic exposure
to ethoprop from food and water will utilize 2.7% of the cPAD for
infants less than 1 year old and children 1 to 2 years old, the
population groups receiving the greatest exposure. Using a drinking
water estimate for ethoprop and its degradates of 0.52 ppb, equivalent
to more than 2x the maximum measured value, chronic dietary exposure to
ethoprop from food and water will occupy 4.2% of the cPAD for infants
less than 1 year old and 3.4% for children 1 to 2 years old. There are
no residential uses for ethoprop.
[[Page 53731]]
3. Short-term and intermediate-term risk. Short-term and
intermediate-term aggregate exposures take into account short-term or
intermediate-term residential exposure plus chronic exposure to food
and water (considered to be a background exposure level). Ethoprop is
not registered for any use patterns that would result in residential
exposure. Therefore, the short-term or intermediate-term aggregate risk
is the sum of the risk from exposure to ethoprop through food and water
and will not be greater than the chronic aggregate risk.
4. Aggregate cancer risk for U.S. population. Using the food
exposure assumptions described in this unit for the cancer risk
assessment and the highest measured concentrations of ethoprop and its
degradates from the targeted drinking water monitoring surveys (0.231
ppb), EPA has concluded that exposure to ethoprop from food and water
will result in a lifetime cancer risk of 4 x 10-7 for the
U.S. population. EPA generally considers cancer risks in the range of
10-6 or less to be negligible. Residues of ethoprop and its
degradates of concern in drinking water could be as high as 5 ppb (22x
the highest measured monitoring value) before lifetime cancer risk
exceeded this level.
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 ethoprop residues.
IV. Other Considerations
A. Analytical Enforcement Methodology
Adequate enforcement methodology is available to enforce the
tolerance expression. Two gas chromatography (GC)/sulfur
microcoulometric detection methods are available in the Pesticide
Analytical Methods, Volume II (Methods I and A). Both involve solvent
extraction and clean-up by sweep co-distillation and have a reported
limit of quantitation (LOQ) of 0.01 ppm for most commodities.
B. International Residue Limits
There are no Canadian, CODEX or Mexican Maximum Residue Limits
established for residues of ethoprop on mint or hops.
V. Conclusion
Therefore, tolerances are established for residues of ethoprop, O-
ethyl S,S-dipropyl phosphorodithioate, in or on hop, dried cones;
peppermint, tops; and spearmint, tops at 0.02 ppm.
VI. Statutory and Executive Order Reviews
This final rule establishes tolerances under section 408(d) of
FFDCA in response to petitions submitted to the Agency. The Office of
Management and Budget (OMB) has exempted these types of actions from
review under Executive Order 12866, entitled Regulatory Planning and
Review (58 FR 51735, October 4, 1993). Because this final rule has been
exempted from review under Executive Order 12866, this final rule is
not subject to Executive Order 13211, entitled Actions Concerning
Regulations That Significantly Affect Energy Supply, Distribution, or
Use (66 FR 28355, May 22, 2001) or Executive Order 13045, entitled
Protection of Children from Environmental Health Risks and Safety Risks
(62 FR 19885, April 23, 1997). This final rule does not contain any
information collections subject to OMB approval under the Paperwork
Reduction Act (PRA), 44 U.S.C. 3501 et seq., nor does it require any
special considerations under Executive Order 12898, entitled Federal
Actions to Address Environmental Justice in Minority Populations and
Low-Income Populations (59 FR 7629, February 16, 1994).
Since tolerances and exemptions that are established on the basis
of a petition under section 408(d) of FFDCA, such as the tolerance in
this final rule, do not require the issuance of a proposed rule, the
requirements of the Regulatory Flexibility Act (RFA) (5 U.S.C. 601 et
seq.) do not apply.
This final rule directly regulates growers, food processors, food
handlers, and food retailers, not States or tribes, nor does this
action alter the relationships or distribution of power and
responsibilities established by Congress in the preemption provisions
of section 408(n)(4) of FFDCA. As such, the Agency has determined that
this action will not have a substantial direct effect on States or
tribal governments, on the relationship between the national government
and the States or tribal governments, or on the distribution of power
and responsibilities among the various levels of government or between
the Federal Government and Indian tribes. Thus, the Agency has
determined that Executive Order 13132, entitled Federalism (64 FR
43255, August 10, 1999) and Executive Order 13175, entitled
Consultation and Coordination with Indian Tribal Governments (65 FR
67249, November 9, 2000) do not apply to this final rule. In addition,
this final rule does not impose any enforceable duty or contain any
unfunded mandate as described under Title II of the Unfunded Mandates
Reform Act of 1995 (UMRA) (Public Law 104-4).
This action does not involve any technical standards that would
require Agency consideration of voluntary consensus standards pursuant
to section 12(d) of the National Technology Transfer and Advancement
Act of 1995 (NTTAA), Public Law 104-113, section 12(d) (15 U.S.C. 272
note).
VII. Congressional Review Act
The Congressional Review Act, 5 U.S.C. 801 et seq., generally
provides that before a rule may take effect, the agency promulgating
the rule must submit a rule report to each House of the Congress and to
the Comptroller General of the United States. EPA will submit a report
containing this rule and other required information to the U.S. Senate,
the U.S. House of Representatives, and the Comptroller General of the
United States prior to publication of this final rule in the Federal
Register. This final rule is not a ``major rule'' as defined by 5
U.S.C. 804(2).
List of Subjects in 40 CFR Part 180
Environmental protection, Administrative practice and procedure,
Agricultural commodities, Pesticides and pests, Reporting and
recordkeeping requirements.
Dated: September 8, 2008.
Donald R. Stubbs,
Acting Director, Registration Division, Office of Pesticide Programs.
0
Therefore, 40 CFR chapter I is amended as follows:
PART 180--[AMENDED]
0
1. The authority citation for part 180 continues to read as follows:
Authority: 21 U.S.C. 321(q), 346a and 371.
0
2. Section 180.262 is amended by alphabetically adding the following
commodities to the table in paragraph (a) to read as follows:
Sec. 180.262 Ethoprop; tolerances for residues.
(a) * * *
------------------------------------------------------------------------
Parts per
Commodity million
------------------------------------------------------------------------
* * * * *
Hop, dried cones........................................ 0.02
* * * * *
Peppermint, tops........................................ 0.02
* * * * *
Spearmint, tops......................................... 0.02
* * * * *
------------------------------------------------------------------------
[[Page 53732]]
* * * * *
[FR Doc. E8-21589 Filed 9-16-08; 8:45 am]
BILLING CODE 6560-50-S