[Federal Register: February 13, 2008 (Volume 73, Number 30)]
[Rules and Regulations]
[Page 8212-8218]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr13fe08-14]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
[EPA-HQ-OPP-2007-0637; FRL-8345-1]
1,3-Dichloropropene and metabolites; Pesticide Tolerance
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
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SUMMARY: This regulation establishes a tolerance for combined residues
of 1,3-dichloropropene and metabolites in or on grape. Dow
AgroSciences, LLC requested this tolerance under the Federal Food,
Drug, and Cosmetic Act (FFDCA).
DATES: This regulation is effective February 13, 2008. Objections and
requests for hearings must be received on or before April 14, 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-2007-0637. To access the
electronic docket, go to http://www.regulations.gov, select ``Advanced
Search,'' then ``Docket Search.'' Insert the docket ID number where
indicated and select the ``Submit'' button. Follow the instructions on
the regulations.gov website to view the docket index or access
available documents. All documents in the docket are listed in the
docket index available in 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-
[[Page 8213]]
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: Mary L. Waller, Registration Division
(7505P), Office of Pesticide Programs, Environmental Protection Agency,
1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone
number: (703) 308-9354; e-mail address: waller.mary@epa.gov.
SUPPLEMENTARY INFORMATION:
I. General Information
A. Does this Action Apply to Me?
You may be potentially affected by this action if you are an
agricultural producer, food manufacturer, or pesticide manufacturer.
Potentially affected entities may include, but are not limited to those
engaged in the following activities:
Crop production (NAICS code 111), e.g., agricultural
workers; greenhouse, nursery, and floriculture workers; farmers.
Animal production (NAICS code 112), e.g., cattle ranchers
and farmers, dairy cattle farmers, livestock farmers.
Food manufacturing (NAICS code 311), e.g., agricultural
workers; farmers; greenhouse, nursery, and floriculture workers;
ranchers; pesticide applicators.
Pesticide manufacturing (NAICS code 32532), e.g.,
agricultural workers; commercial applicators; farmers; greenhouse,
nursery, and floriculture workers; residential users.
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 an electronic copy of this Federal
Register document through the electronic docket 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, 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-2007-0637 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 April 14, 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-2007-0637, 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'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 19, 2007 (72 FR 53575-53577)
(FRL-8144-3), EPA issued a notice pursuant to section 408(d)(3) of
FFDCA, 21 U.S.C. 346a(d)(3), announcing the filing of a pesticide
petition (PP 1F6253) by Dow AgroSciences, LLC, 9330 Zionsville Road,
Indianapolis, IN 46268. The petition requested that 40 CFR part 180 be
amended by establishing a tolerance for residues of the fungicide, 1,3-
dichloropropene, in or on grape at 0.009 parts per million (ppm). That
notice referenced a summary of the petition prepared by Dow
AgroScience, LLC, the registrant, which is available to the public in
the docket, at http://www.regulations.gov. There were no comments
received in response to the notice of filing. Based upon review of the
data supporting the petition, EPA has revised and raised the tolerance
level to include the combined residues of the parent chemical, cis- and
trans-1,3 dichloropropene, and the metabolites, cis- and trans-3-
chloroacrylic acid and cis- and trans-3-chloroallyl alcohol which are
considered to be of equal toxicity to the parent chemical.
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....'' These provisions were added to FFDCA by the Food Quality
Protection Act (FQPA) of 1996.
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 the petitioned-for tolerance
for the combined residues of cis- and trans-1,3-dichloropropene, cis-
and trans-3-chloroacrylic acid, and cis- and trans-3-chloroallyl
alcohol (1,3-dichloropropene and metabolites) on grape at 0.018 ppm.
EPA's assessment of exposures and risks associated with establishing
the tolerance follows.
[[Page 8214]]
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 toxicology database is considered to be adequate to support the
proposed and existing uses of 1,3-dichloropropene. 1,3-Dichloropropene
showed moderate acute toxicity by the oral and dermal exposure routes
(Toxicity Category II), was moderately irritating to the eye and skin,
and was a dermal sensitizer in guinea pigs. It is classified as
Toxicity Category IV for acute inhalation toxicity and produced
tremors, convulsions, salivation, lacrimation, diarrhea, lethargy and
death at concentrations 647 ppm or higher.
Consistent with the irritant properties of 1,3-dichloropropene,
there was evidence of degenerative changes in the nasal olfactory
epithelium and histopathological changes of the respiratory epithelium
in rats and mice after subchronic inhalation exposure. Following
chronic inhalation exposure, the olfactory region of the nasal cavity
appeared to be the target organ in rats while lung adenomas were
induced in mice. Similarly, following oral exposure, 1,3-
dichloropropene induced histopathological lesions in rats and/or mice
including forestomach squamous cell papillomas and carcinomas, liver
masses/neoplastic nodules, urinary bladder carcinomas, and alveolar/
brochiolaradenomas. Increases in hematopoietic activity and decreased
body weights were also noted in dogs and mice, respectively.
Accordingly, 1,3-dichloropropene has been classified as ``likely to be
carcinogenic to humans'' via both the oral and inhalation routes. As a
result, cancer potency factors (Q1*) have been calculated for both
routes of exposure.
Specific information on the studies received and the nature of the
adverse effects caused by 1,3-dichloropropene and metabolites 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. The risk assessment dated January
24, 2008 is available in the docket established by this action, which
is described under ADDRESSES, and is identified as EPA-HQ-OPP-2007-0637
in that docket.
B. Toxicological Endpoints
For hazards that have a threshold below which there is no
appreciable risk, the toxicological level of concern (LOC) is derived
from 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) is
sometimes used for risk assessment. Uncertainty/safety factors (UFs)
are used in conjunction with the LOC 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
risks by comparing aggregate 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 LOC by all
applicable UFs. Short-, intermediate-, and long-term risks are
evaluated by comparing aggregate exposure to the LOC to ensure that the
margin of exposure (MOE) called for by the product of all applicable
UFs is not exceeded.
For non-threshold risks, the Agency assumes that any amount of
exposure will lead to some degree of risk and estimates risk in terms
of the probability of occurrence of additional adverse cases.
Generally, cancer risks are considered non-threshold. 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/fedrgstr/EPA-PEST/1997/November/Day-26/p30948.htm
.
A summary of the toxicological endpoints for 1,3-dichloropropene
and metabolites used for human risk assessment can be found at http://www.regulations.gov
in the document titled 1,3-Dichloropropene:
Proposed New Use for Drip Irrigation in Vineyards: HED Human Health
Risk Assessment at page 21 in docket ID number EPA-HQ-OPP-2007-0637.
C. Exposure Assessment
1. Dietary exposure from food and feed uses. In evaluating dietary
exposure to 1,3-dichloropropene and metabolites, EPA considered
exposure under the petitioned-for tolerance. There are no other
tolerances for 1,3-dichloropropene and metabolites. EPA assessed
dietary exposures from 1,3-dichloropropene and metabolites 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.
No such effects were identified in the toxicological studies for
1,3-dichloropropene and metabolites; therefore, a quantitative acute
dietary exposure assessment is unnecessary.
ii. Chronic exposure. In conducting the chronic dietary exposure
assessment EPA used the food consumption data from the USDA 1994-1996,
or 1998 Continuing Survey of Food Intake by Individuals (CSFII). As to
residue levels in food, EPA relied upon anticipated residues and
assumed 100 percent crop treated (PCT). Residues of cis- and trans-1,3-
dichloropropene and three of the four metabolites were assumed to be at
one-half the limit of detection (0.001 ppm) since residues were non-
detectable in all field trials at shorter pre-harvest intervals (PHI)
than the proposed use pattern. Residues at the proposed PHI in one
trial of one metabolite were at the limit of quantitation (0.003 ppm),
so the LOQ was used. The metabolites were assumed to have equal
toxicity to the parent compound, so the total anticipated residue used
in the dietary assessment for the chronic analyses was 0.0055 ppm.
iii. Cancer. The cancer dietary exposure assessment utilized the
same data and assumptions used in the chronic dietary exposure
assessment. For dietary exposure to 1,3-dichloropropene, an oral cancer
potency factor (Q1* of 1.22 X 10-1 (mg/kg/day)-1)
was used to assess cancer 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 pursuant
to FFDCA section 408(f)(1) require 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 this tolerance.
[[Page 8215]]
2. Dietary exposure from drinking water. The Agency lacks
sufficient surface water monitoring data to complete a comprehensive
dietary exposure analysis and risk assessment for 1,3-dichloropropene
and metabolites in drinking water. Because the Agency does not have
comprehensive surface water monitoring data, drinking water
concentration estimates from surface water sources are made by reliance
on simulation or modeling taking into account data on the environmental
fate characteristics of 1,3-dichloropropene and metabolites. Further
information regarding EPA drinking water models used in pesticide
exposure assessment can be found at http://www.epa.gov/oppefed1/models/water/index.htm
.
Based on the Pesticide Root Zone Model/Exposure Analysis Modeling
System (PRZM/EXAMS), the estimated environmental concentrations (EECs)
of 1,3-dichloropropene and metabolites for chronic exposures are
estimated to be 16.2 parts per billion (ppb). The limited surface water
monitoring data available from areas of high use did not show
detectable residues of 1,3-dichloropropene in 123 samples.
There is sufficient data for tap water from groundwater wells
available for 1,3-dichloropropene and metabolites. A total of 518 wells
were selected in the Central Columbia Plateau, Upper Snake River Basin,
North Platte River, Albermarle-Pamlico Sound, and the George/Florida
basins. The wells were intended to be among the most vulnerable wells
available for sampling in each region because they were in high use
areas, were among the shallowest in each region, and were located in
close proximity to fields that had received 1,3-dichloropropene
applications in the recent past. 1,3-Dichloropropene and metabolites
were not found above 0.145 ppb in 5,800 samples.1,3-Dichloropropene or
its degradates were detected in 12% of the wells. Only three wells had
two detections over the course of the study; no wells had more than two
detections. Of the approximately 5,800 samples, only 68 detections were
observed for either the parent compound or the metabolites.
Modeled surface water estimates of drinking water concentrations
and the maximum ground water concentration from monitoring data were
directly entered into the dietary exposure model. For chronic dietary
risk assessment, the surface drinking water concentration value of 16.2
ppb was used and the ground drinking water concentration value of 0.14
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).
1,3-Dichloropropene is not registered for use on any sites that
would result in residential exposure. However, due to the volatility of
1,3-dichloropropene, residential bystander exposure may occur when 1,3-
dichloropropene is applied to agricultural fields near residential
areas. Residential bystander exposure may occur because of emissions
from treated fields. These emissions can travel to non-target areas and
are referred to as bystander exposure. Bystander exposure can occur as
a result of being in contact with residues that are emitted from a
known single source (e.g., a single application to an agricultural
field near a residential area) and from multiple sources (e.g.,
applications to numerous agricultural fields) within a localized
agricultural region (ambient air exposure).
i. Inhalation exposure from a single source. Acute exposures to
bystanders from single post-plant agricultural field fumigation events
and their associated risks were calculated using the distributional/
probabilistic modeling method. Distributional modeling was done with
the Probabilistic Exposure and Risk Model for Fumigants (PERFUM).
Exposures were also analyzed using the actual field study data (i.e,
the monitoring method). Additional information on the methods used to
assess bystander risks are given in Section 6.1.1 from the Phase 5
Registration Eligibility Decision.: Methods Used to Calculate Bystander
Exposures and Risks From Known Sources located at http://www.regulations.gov
in docket ID number EPA-HQ-OPP-2005-0124-0052, page
27.
a. Acute exposure was estimated by using the maximum 24-hour time-
weighted average (TWA) from each field volatility study.
b. Short-term exposure was estimated by using the highest 7-day
average for each direction from each field volatility study.
c. Intermediate-term exposures (consecutive exposures lasting 30
days to several months) is expected to be less likely since 1,3-
dichloropropene products are only used 1 to 2 times per field each
year.
d. Chronic exposure is not expected since it is unlikely that
bystanders will be continually exposed to significant concentrations of
1,3-dichloropropene for 6 consecutive months or longer. Chronic
exposure from multiple (ambient air) sources is more likely and
described in section 3 (ii)(c).
e. Cancer risks to 1,3-dichloropropene were estimated for multiple
(ambient air) sources as that exposure scenario is more representative
of a lifetime of exposure and are described in the following section
3(ii)(d).
ii. Inhalation exposure from ambient air sources. Exposure to 1,3-
dichloropropene from ambient air was evaluated using monitoring data
from California. These data reflect existing pre-plant fumigation uses
that are applied at rates over 10 times the rate of the proposed post-
plant fumigation use on grapes. These data consist of two basic types
that include targeted monitoring that occurred in a high use area
during the season of use. The other type of data was collected as part
of the routine Toxic Air Contaminant (TAC) program and focus on
background levels in urban environments.
a. Acute exposure was estimated by using the maximum 24-hour time-
weighted average (TWA) from the monitoring data.
b. Short-term and intermediate-term exposures were estimated by
comparing the mean of the weekly mean estimate from the monitoring
data.
c. Chronic exposures were calculated using the targeted regional
source ambient data. These calculations should be considered as
rangefinder estimates of exposure only because of a lack of monitoring
studies specifically designed for this purpose. Short- and
intermediate-term estimates were amortized to reflect a potential for
exposure of 180 days out of each calendar year in order to calculate
chronic estimates of exposure. This was based on the approximate use
patterns for 1,3-dichloropropene over a year in high use areas. Results
based on all of these calculations, as indicated above, do not
represent a risk concern to the Agency and in most cases risks were far
below the target level of concern (e.g., by orders of magnitude). There
were no ambient monitoring studies targeting areas of high use that
collected air samples over an entire year that would be considered
representative of a chronic exposure pattern. In these studies the
focus was more on the actual season of use so these data were typically
collected for only 9 weeks or so which represents the duration of the
typical application season. However, in order to be able to evaluate
the possibility of chronic exposures in high use areas the Agency
utilized the seasonal mean of means from the high use areas and
supposed that exposures could be maintained at this rate for a
[[Page 8216]]
sustained period of 6 months which is twice as long as a normal
application season. This approach does have some uncertainty associated
with it but the Agency believes that this approach does not
underestimate exposure because monitoring data were collected in the
season of use in areas of high use. Additionally, risks calculated
based on this method, as indicated above, are typically well below the
Agency's level of concern. In addition to using the targeted monitoring
data, the Agency also used the urban background monitoring data to
calculate chronic risks. In this case, the data were intentionally
designed to be used to evaluate longer-term exposure levels. Many of
the samples collected in this network did not even contain measurable
residues over the course of the monitoring years in question but
chronic risks were still evaluated as a precautionary measure.
d. For cancer risk assessment, the lifetime average daily exposure
(LADE) was calculated using the mean of weekly means and assumed that
exposure lasts the length of the longest monitoring period (9 weeks/63
days).
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.''
Unlike other pesticides for which EPA has followed a cumulative
risk approach based on a common mechanism of toxicity, EPA has not made
a common mechanism of toxicity finding as to 1,3-dichloropropene and
any other substances and 1,3-dichloropropene does not appear to produce
a toxic metabolite produced by other substances. For the purposes of
this tolerance action, therefore, EPA has not assumed that 1,3-
dichloropropene has a common mechanism of toxicity with other
substances. For information regarding EPA's efforts to determine which
chemicals have a common mechanism of toxicity and to evaluate the
cumulative effects of such chemicals, see EPA's website at http://www.epa.gov/pesticides/cumulative
.
D. Safety Factor for Infants and Children
1. In general. Section 408 of FFDCA provides that EPA shall apply
an additional (``10X'') tenfold margin of safety for infants and
children in the case of threshold effects to account for prenatal and
postnatal toxicity and the completeness of the database 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. In
applying this provision, EPA either retains the default value of 10X
when reliable data do not support the choice of a different factor, or,
if reliable data are available, EPA uses a different additional FQPA
safety factor value based on the use of traditional UFs and/or special
FQPA safety factors, as appropriate.
2. Prenatal and postnatal sensitivity. There is no evidence
(quantitative or qualitative) of susceptibility and no residual
uncertainties with regard to pre- and/or post-natal toxicity following
in utero exposure to rats or rabbits and pre- and/or post-natal
exposures to rats.
3. Conclusion. EPA has determined that reliable data show that it
would be safe for infants and children to reduce the FQPA safety factor
to 1X. That decision is based on the following findings:
i. The toxicity database for 1,3-dichloropropene is complete.
ii. There is no indication that 1,3-dichloropropene is a neurotoxic
chemical and there is no need for a developmental neurotoxicity study
or additional UFs to account for neurotoxicity.
iii. There is no evidence that 1,3-dichloropropene results in
increased susceptibility following in utero and/or post-natal exposure
in rats or rabbits in the prenatal developmental studies or in young
rats in the 2-generation reproduction study.
iv. There are no residual uncertainties identified in the exposure
databases. The dietary food exposure assessments were performed based
on 100% crop treated and average anticipated residues. Conservative
surface water modeling estimates were used, and sufficient monitoring
data were used to assess ground water concentrations. There are no
residential uses of 1,3-dichloropropene and conservative modeling was
used to estimate bystander exposure. These assessments will not
underestimate the exposure and risks posed by 1,3-dichloropropene and
metabolites.
E. Aggregate Risks and Determination of Safety
Safety is assessed for acute and chronic risks by comparing
aggregate 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 LOC by all applicable UFs. For
linear cancer risks, EPA calculates the probability of additional
cancer cases given aggregate exposure. Short-, intermediate-, and long-
term risks are evaluated by comparing aggregate exposure to the LOC to
ensure that the margin of expsure (MOE) called for by the product of
all applicable UFs is not exceeded.
For the acute, short-, intermediate-, and long-term assessments,
the toxicity endpoints selected for inhalation and dietary exposures
should not be aggregated since no common endpoints were identified at
the LOAEL in studies conducted via the oral or inhalation routes. 1,3-
Dichloropropene has been classified as likely to be carcinogenic to
humans via the oral and inhalation routes. However, the types of tumors
observed in the inhalation and oral studies were different. Therefore,
the oral and inhalation exposures were not aggregated.
1. Acute risk. An endpoint was not selected for acute dietary risk
assessment because there were no effects attributable to a single dose
(exposure) via the oral route. Therefore, 1,3-dichloropropene is not
expected to pose an acute dietary risk.
For residential bystander acute inhalation risk resulting from
exposure to a single source, the lowest acute MOE was 400 based on the
application rate in the field volatility data and the lowest acute MOE
was 160 based on the maximum label rate. The risk estimates did not
exceed the level of concern using the PERFUM modeling method. For
residential bystander acute inhalation risk resulting from exposure to
ambient air sources, the lowest acute MOE was 2,700 based on California
ambient air monitoring data. The MOEs do not exceed the Agency's level
of concern of < 30.
2. Chronic risk. Using the exposure assumptions described in this
unit for chronic exposure, EPA has concluded that exposure to 1,3-
dichloropropene and metabolites from food and water (ground water
sources) will utilize < 1% of the cPAD for the most highly exposed
population group (children 1 to 2 years old) and from food and water
(surface water sources) will utilize < 5% of the cPAD for the most
highly exposed population group, infants < 1 year old.
Residential bystander chronic inhalation exposure from a single
source is not expected to occur and therefore, does not pose an
inhalation risk. For residential bystander chronic inhalation risk
resulting from exposure to ambient air sources, the lowest chronic MOE
was 130 based on California ambient air monitoring data. The MOE does
not
[[Page 8217]]
exceed the Agency's level of concern of < 30.
3. Short-term risk. For residential bystander short-term inhalation
risk resulting from exposure to a single source, the lowest short-term
MOE was 60 based on the application rate in the field volatility data
and based on the maximum label rate. For residential bystander short-
term inhalation risk resulting from exposure to ambient air sources,
the lowest short-term MOE was 1,700 based on California ambient air
monitoring data. The MOEs do not exceed the Agency's level of concern
of < 30.
4. Intermediate-term risk. Residential bystander intermediate-term
inhalation exposure from a single source is unlikely to occur and
therefore, does not pose an inhalation risk. For residential bystander
intermediate-term inhalation risk resulting from exposure to ambient
air sources, the lowest intermediate-term MOE was 70 based on
California ambient air monitoring data. The MOE does not exceed the
Agency's level of concern of < 30.
5. Aggregate cancer risk for U.S. population. The aggregated food
and water risk represent upper bound risks for a person living in
agricultural areas where 1,3-dichloropropene is used extensively or
where a person obtains drinking water from an aquifer that led directly
from an area where 1,3-dichloropropene was used. The aggregate chronic
dietary cancer risk estimates for the general U.S. population resulting
from exposure to 1,3-dichloropropene and metabolites in food and water
(ground water sources) is 7 X 10-7 and from exposure to 1,3-
dichloropropene and metabolites in food and water (surface water
sources) is 4 X 10-5.
Although risk for drinking water from surface water sources for
1,3-dichloropropene exceeds the Agency's level of concern (risk
estimates generally in the range of 1 in 1 million, interpreted as > 1
to 3 X 10-6); it should be noted that concentrations of 1,3-
dichloropropene in tap water from ground water wells were approximately
100 times lower than those found in the field ground water study and
several orders of magnitude lower than modeled estimates of 1,3-
dichloropropene in groundwater. Therefore, it is highly likely that
actual drinking water concentrations of 1,3-dichloropropene from
surface water sources would also be much lower. 1,3-Dichloropropene and
its metabolites are highly volatile compounds, and the models used to
generate surface water and ground water estimates are not designed for
volatile chemicals. The limited surface water monitoring data available
in areas of high use do not show any detections of 1,3-dichloropropene
and its degradates. Therefore, the Agency does not have a concern for
the aggregate cancer risk from oral exposures to 1,3-dichloropropene
and its metabolites.
Cancer risk was estimated using 1,3-dichloropropene ambient air
monitoring data collected from over 20 sites over multiple years to
estimate exposure over a lifetime. These sites were in areas of high
use and in urban environments. The cancer risk estimates for all but
one monitoring site, in a high use area, ranged from 2 X
10-6 to 9 X 10-8, which are below the Agency's
level of concern. The monitoring data for the one site resulted in a
risk estimate of 6 X 10-6, which does exceed the Agency's
level of concern. However, risks calculated using data from the same
site in the following year was almost two orders of magnitude lower.
Therefore, over a lifetime of exposure, the risk estimates would likely
be below the level of concern. It should be noted that in more
populated urban environments, air concentrations were below the
analytical limit of detection in 21 of 28 sites/year combinations
considered. In the remaining seven site/year combinations, values were
measured but did not result in cancer risks of concern. Therefore, the
Agency does not have a concern for the cancer risk from 1,3-
dichloropropene.
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 1,3-dichloropropene and metabolites residues.
IV. Other Considerations
A. Analytical Enforcement Methodology
Dow AgroSciences, LLC submitted a gas chromatography/
massspectroscopy (GC/MS) method, Method GRM 99.09.R1, for
thedetermination of residues of cis- and trans-1,3-dichloropropene. The
method was adequately validated using fortified samples of grape.
Recoveries of cis-1,3-dichloropropene ranged from 70% to 114% and
recoveries of trans-1,3-dichloropropene ranged from 77% to 113% from
samples fortified at 0.003, 0.010, 0.050, and 0.50 ppm. The
fortification levels used in method validation are adequate to bracket
expected residue levels. Adequate independent laboratory validation
(ILV) datawere submitted for Method GRM 99.09.R1 using samples of
grape.
Dow AgroSciences, LLC submitted a GC/MS method, Method GRM99.18,
for the determination of residues of 3-chloroallyl alcohol and 3-
chloroacrylic acid. The validated LOQ is 0.003 ppm for each analytein
grape. The method was adequately validated using fortified samplesof
grape. Recoveries of cis-3-chloroallyl alcohol ranged from 74% to 90%,
recoveries of trans-3-chloroallyl alcohol ranged from 82% to 95%,
recoveries of cis-chloroacrylic acid ranged from 93% to 98%, and
recoveries of trans-chloroacrylic acid ranged from 91% to 96% from
samples fortified at 0.003, 0.006, and 0.030 ppm. The fortification
levels used in method validation are adequate to bracket expected
residue levels. The Agency has tentatively concluded that the
metabolite method is suitable for enforcement.
Adequate enforcement methodology (GC/MS) is available to enforcethe
tolerance expression. The method may be requested from:
Chief,Analytical Chemistry Branch, Environmental Science Center,
701Mapes Rd., Ft. Meade, MD 20755-5350; telephone number: (410) 305-
2905; e-mail address: residuemethods@epa.gov.
B. International Residue Limits
There are no Canadian or Codex Maximum Residue limits for residues
of 1,3-dichloropropene for any commodity.
C. Conditions
1. An independent laboratory validation of Method GRM 99.18
andmulti-residue method testing will be required as confirmatory data.
2. In order to refine the exposure estimates from PRZM-EXAMS, the
following data will be required: an aerobic soil metabolism study on
additional soils (parent and metabolites); an aerobic aquatic
metabolism study (parent and metabolites); an aqueous photolysis study
(indirect and parent); a soil photolysis study (parent); and a
photolysis/oxidation in air study (parent).
V. Conclusion
Therefore, the tolerance is established for combined residues of
cis- and trans-1,3-dichloropropene, cis- and trans-3-chloroacrylic
acid, and cis- and trans-3-chloroallyl alcohol, in or on grape at 0.018
ppm.
VI. Statutory and Executive Order Reviews
This final rule establishes a tolerance under section 408(d) of
FFDCA in response to a petition submitted to the Agency. The Office of
Management and
[[Page 8218]]
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 rule has been exempted from
review under Executive Order 12866, this rule is not subject to
Executive Order 13211, 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 6, 2000) do not apply to this rule. In addition, This
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: February 1, 2008.
Lois Rossi,
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 180.636 is added to subpart C to read as follows:
Sec. 180.636 1,3-dichloropropene; tolerances for residues.
(a) General. Tolerances are established for the combined residues
of the fungicide cis- and trans-1,3-dichloropropene and its metabolites
cis- and trans-3-chloroacrylic acid, and cis- and trans-3-chloroallyl
alcohol in or on the following commodities.
------------------------------------------------------------------------
Parts per
Commodity million
------------------------------------------------------------------------
Grape...................................................... 0.018
------------------------------------------------------------------------
(b) Section 18 emergency exemptions. [Reserved]
(c) Tolerances with regional registrations. [Reserved]
(d) Indirect or inadvertent residues. [Reserved]
[FR Doc. E8-2480 Filed 2-12-08; 8:45 am]
BILLING CODE 6560-50-S