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Ethalfluralin (IR-4). November 14, 2001. Three pesticide petitions to establish tolerances for residues in or on Canola, Safflower and Dill at 0.05 ppm. Federal Register.
http://www.epa.gov/fedrgstr/EPA-PEST/2001/November/Day-14/p28198.htm
[Federal Register: November 14, 2001 (Volume 66, Number 220)]
[Notices]
[Page 57082-57086]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr14no01-81]
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ENVIRONMENTAL PROTECTION AGENCY
[PF-1052; FRL-6808-9]
Notice of Filing a Pesticide Petition to Establish a Tolerance
for a Certain Pesticide Chemical in or on Food
AGENCY: Environmental Protection Agency (EPA).
ACTION: Notice.
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SUMMARY: This notice announces the initial filing of a pesticide
petition proposing the establishment of regulations for residues of a
certain pesticide chemical in or on various food commodities.
DATES: Comments, identified by docket control number PF-1052, must be
received on or before December 14, 2001.
ADDRESSES: Comments may be submitted by mail, electronically, or in
person. Please follow the detailed instructions for each method as
provided in Unit I.C. of the SUPPLEMENTARY INFORMATION. To ensure
proper receipt by EPA, it is imperative that you identify docket
control number PF-1052 in the subject line on the first page of your
response.
FOR FURTHER INFORMATION CONTACT: By mail: Hoyt Jamerson, Registration
Support Branch, Registration Division (7505C), Office of Pesticide
Programs, Environmental Protection Agency, 1200 Pennsylvania Ave., NW.,
Washington, DC 20460; telephone number: (703) 308-9368; e-mail address:
jamerson.hoyt@epa.gov.
SUPPLEMENTARY INFORMATION:
I. General Information
A. Does this Action Apply to Me?
You may be affected by this action if you are an agricultural
producer, food manufacturer or pesticide manufacturer. Potentially
affected categories and entities may include, but are not limited to:
------------------------------------------------------------------------
Examples of
Categories NAICS codes potentially
affected entities
------------------------------------------------------------------------
Industry 111 Crop production
112 Animal production
311 Food manufacturing
32532 Pesticide
manufacturing
------------------------------------------------------------------------
This listing is not intended to be exhaustive, but rather provides
a guide for readers regarding entities likely to be
[[Page 57083]]
affected by this action. Other types of entities not listed in the
table could also be affected. The North American Industrial
Classification System (NAICS) codes have been provided to assist you
and others in determining whether or not this action might apply to
certain entities. If you have questions regarding the applicability of
this action to a particular entity, consult the person listed under FOR
FURTHER INFORMATION CONTACT.
B. How Can I Get Additional Information, Including Copies of this
Document and Other Related Documents?
1. Electronically. You may obtain electronic copies of this
document, and certain other related documents that might be available
electronically, from the EPA Internet Home Page at http://www.epa.gov/.
To access this document, on the Home Page select ``Laws and
Regulations,'' ``Regulations and Proposed Rules,'' and then look up the
entry for this document under the ``Federal Register--Environmental
Documents.'' You can also go directly to the Federal Register listings
at http://www.epa.gov/fedrgstr/.
2. In person. The Agency has established an official record for
this action under docket control number PF-1052. The official record
consists of the documents specifically referenced in this action, any
public comments received during an applicable comment period, and other
information related to this action, including any information claimed
as confidential business information (CBI). This official record
includes the documents that are physically located in the docket, as
well as the documents that are referenced in those documents. The
public version of the official record does not include any information
claimed as CBI. The public version of the official record, which
includes printed, paper versions of any electronic comments submitted
during an applicable comment period, is available for inspection in the
Public Information and Records Integrity Branch (PIRIB), Rm. 119,
Crystal Mall #2, 1921 Jefferson Davis Highway, Arlington, VA., from
8:30 a.m. to 4 p.m., Monday through Friday, excluding legal holidays.
The PIRIB telephone number is (703) 305-5805.
C. How and to Whom Do I Submit Comments?
You may submit comments through the mail, in person, or
electronically. To ensure proper receipt by EPA, it is imperative that
you identify docket control number PF-1052 in the subject line on the
first page of your response.
1. By mail. Submit your comments to: Public Information and Records
Integrity Branch (PIRIB), Information Resources and Services Division
(7502C), Office of Pesticide Programs (OPP), Environmental Protection
Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460.
2. In person or by courier. Deliver your comments to: Public
Information and Records Integrity Branch (PIRIB), Information Resources
and Services Division (7502C), Office of Pesticide Programs (OPP),
Environmental Protection Agency, Rm. 119, Crystal Mall #2, 1921
Jefferson Davis Highway, Arlington, VA. The PIRIB is open from 8:30
a.m. to 4 p.m., Monday through Friday, excluding legal holidays. The
PIRIB telephone number is (703) 305-5805.
3. Electronically. You may submit your comments electronically by
e-mail to: opp-docket@epa.gov, or you can submit a computer disk as
described above. Do not submit any information electronically that you
consider to be CBI. Avoid the use of special characters and any form of
encryption. Electronic submissions will be accepted in Wordperfect 6.1/
8.0 or ASCII file format. All comments in electronic form must be
identified by docket control number PF-1052. Electronic comments may
also be filed online at many Federal Depository Libraries.
D. How Should I Handle CBI That I Want to Submit to the Agency?
Do not submit any information electronically that you consider to
be CBI. You may claim information that you submit to EPA in response to
this document as CBI by marking any part or all of that information as
CBI. Information so marked will not be disclosed except in accordance
with procedures set forth in 40 CFR part 2. In addition to one complete
version of the comment that includes any information claimed as CBI, a
copy of the comment that does not contain the information claimed as
CBI must be submitted for inclusion in the public version of the
official record. Information not marked confidential will be included
in the public version of the official record without prior notice. If
you have any questions about CBI or the procedures for claiming CBI,
please consult the person identified under FOR FURTHER INFORMATION
CONTACT.
E. What Should I Consider as I Prepare My Comments for EPA?
You may find the following suggestions helpful for preparing your
comments:
1. Explain your views as clearly as possible.
2. Describe any assumptions that you used.
3. Provide copies of any technical information and/or data you used
that support your views.
4. If you estimate potential burden or costs, explain how you
arrived at the estimate that you provide.
5. Provide specific examples to illustrate your concerns.
6. Make sure to submit your comments by the deadline in this
notice.
7. To ensure proper receipt by EPA, be sure to identify the docket
control number assigned to this action in the subject line on the first
page of your response. You may also provide the name, date, and Federal
Register citation.
II. What Action is the Agency Taking?
EPA has received a pesticide petition as follows proposing the
establishment and/or amendment of regulations for residues of a certain
pesticide chemical in or on various food commodities under section 408
of the Federal Food, Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 346a.
EPA has determined that this petition contains data or information
regarding the elements set forth in section 408(d)(2); however, EPA has
not fully evaluated the sufficiency of the submitted data at this time
or whether the data support granting of the petition. Additional data
may be needed before EPA rules on the petition.
List of Subjects
Environmental protection, Agricultural commodities, Feed additives,
Food additives, Pesticides and pests, reporting and recordkeeping
requirements.
Dated: October 30, 2001.
Peter Caulkins,
Acting Director, Registration Division, Office of Pesticide Programs.
Summary of Petition
The petitioner summary of the pesticide petition is printed below
as required by section 408(d)(3) of the FFDCA. The summary of the
petition was prepared by the petitioner and represents the views of the
petitioner. EPA is publishing the petition summary verbatim without
editing it in any way. The petition summary announces the availability
of a description of the analytical methods available to EPA for the
detection and measurement of the pesticide chemical residues or an
explanation of why no such method is needed.
[[Page 57084]]
Interregional Research Project Number 4 (IR-4)
9E5037, and 1E6326, and 1E6345
EPA has received three pesticide petitions (9E5037 (canola), 1E6326
(dill), and 1E6345 (safflower)) from Interregional Research Project
Number 4 (IR-4) 681 U.S. Highway # 1, South, North Brunswick, NJ 08902-
3390 proposing, pursuant to section 408(d) of FFDCA, 21 U.S.C. 346a(d),
to amend 40 CFR part 180 by establishing tolerances for residues of
ethalfluralin in or on the raw agricultural commodities (RACs) canola,
safflower and dill at 0.05 parts per million (ppm).
EPA has determined that this petition contain data or information
regarding the elements set forth in section 408(d)(2) of the FFDCA;
however, EPA has not fully evaluated the sufficiency of the submitted
data at this time or whether the data support granting of the petition.
Additional data may be needed before EPA rules on the petition.
A. Residue Chemistry
1. Plant metabolism. Nature of residue studies with 14 C
ethalfluralin have demonstrated very low terminal residues and that
ethalfluralin per se is the residue of concern in plants grown in soil
treated with this compound and that there are no significant metabolic
products. These studies indicate that it is appropriate to base a
tolerance on residues of the parent compound, ethalfluralin.
2. Analytical method. A residue method has been developed and
validated at a limit of quantitation (LOQ) of 0.02 g/g for the
determination of ethalfluralin in canola seed which utilizes capillary
gas chromatography with mass selective detection (GC)/MSD. Validation
data were generated using this method during the analysis of the canola
seed field samples from the magnitude of residue studies.
For safflower, adequate residue analytical methods are available
for purposes of registration based upon the analytical method for
sunflower. A GC method, Method I, with electron capture detection is
listed in the Pesticide Analytical Manual ((PAM), Vol. II, Section
180.416), for tolerance enforcement. Method I is applicable for
analysis of ethalfluralin residues in/on sunflower seed. The limit of
detection is 0.01 ppm.
Dill was analyzed by the method ``Determination of Ethalfluralin in
Agricultural Crops and Soil.'' Residue method number AM-AA-CA-R025-AB-
755, Lilly Research Laboratories, Greenfield, IN (Currently Dow
AgroSciences). The LOQ was 0.050 ppm by a GC with a Ni 63
electron capture detector. Method validation was performed both prior
to and concurrently with sample analysis.
3. Magnitude of residues. In the magnitude of residue field
studies, herbicides containing the active ingredient ethalfluralin [N-
ethyl-N-(2-methyl-2-propenyl)-2,6-dinitro-4-(trifluoromethyl)
benzenamine] were applied in 1996 at eight sites as a preplant
incorporated application. Sonalan l0G herbicide was applied directly to
the soil surface and Sonalan HFP herbicide was diluted in water and
applied in a spray volume of 16-23 gallons/acre. The applications were
made to field plots of canola at the rate of 1.25 lb active ingredient/
acre at all sites except Georgia and Washington, and at the rate of
0.75 lb active ingredient/acre (Georgia and Washington). Three to five
days after application a second incorporation was done and canola seeds
were planted. Samples of canola seed were collected at normal harvest,
87-216 days after the last application. Residues in canola seed
collected at normal harvest were non-detectable based on a method lower
limit of detection of 0.004 ppm.
For safflower, the magnitude of residue data from sunflower are
surrogate data for safflower. The registered uses of ethalfluralin on
sunflowers along with the established tolerances on these commodities
are supported by acceptable field residue data from trials reflecting
the maximum registered use patterns. In all cases, the residues were
<0.01ppm. The reregistration requirements for processing studies were
fulfilled. Adequate processing studies have been conducted on sunflower
seed. Field residue data resulting from up to 5X label rates showed
non-detectable (<0.01ppm) residues of ethalfluralin in sunflower seed.
In dill the magnitude of residue field studies, herbicides
containing the active ingredient ethalfluralin [N-ethyl-N-(2-methyl-2-
propenyl)-2,6-dinitro-4-(trifluoromethyl) benzenamine] were applied in
1997 at three sites. Ethalfluralin formulated as Curbit EC was applied
directly to the soil surface diluted in water and applied in a spray
volume of 36 gallons/acre. The applications were made to field plots of
canola at the rate of 1.5 lb active ingredient/acre and incorporated by
sprinkler irrigation. Samples of dill were collected at normal harvest,
91-100 days after the last application. Residues in fresh and dried
dill collected at normal harvest were non-detectable based on a method
lower limit of detection of 0.05 ppm.
B. Toxicological Profile
1. Acute toxicity. Ethalfluralin is of relatively low toxicity. The
rat oral LD50 is >10,000 milligrams/kilograms (mg/kg). The
acute dermal LD50 in rabbits is >2,000 mg/kg and the acute
rat inhalation LC50 is >0.94 milligrams/Liter (mg/L) air.
Ethalfluralin produced slight eye irritation and slight dermal
irritation in rabbits. A guinea pig dermal sensitization study
conducted by the modified Buehler method found no sensitization,
whereas a study conducted by the Magnusson and Kligman maximization
method showed a positive sensitization reaction. The signal word for
the technical grade active ingredient is Caution.
2. Genotoxicty. Ethalfluralin was weakly mutagenic in activated
strains TA1535 and TA100 of Salmonella typhimurium,but not in strains
TA1537, TA1538, and TA98 in an Ames assay. In a modified Ames assay
with Salmonella typhimurium and Escherichia coli, ethalfluralin was
weakly mutagenic in strains TA1535 and TA100, with and without
activation, and in strain TA98 without activation, at the highest dose.
No mutagenicity was found in the mouse lymphoma assay for forward
mutation. Ethalfluralin did not induce unscheduled DNA synthesis in rat
hepatocytes. In chinese hamster ovary cells, ethalfluralin was negative
without S9 activation, but it was clastogenic with activation.
3. Reproductive and developmental toxicity. The maternal no
observed adverse effect level (NOAEL) of ethalfluralin in rats was 50
mg/kg/day. The maternal lowest observed adverse effect level (LOAEL)
was 250 mg/kg/day, based on decreased body weight (bwt) gain and dark
urine. In this rat study there was no observable developmental
toxicity. The developmental NOAEL in rats was 1,000 mg/kg/day, the
highest dose. In rabbits the NOAELs for maternal and developmental
toxicity were 75 mg/kg/day. The maternal LOAEL at 150 mg/kg/day was
based on abortions and decreased food consumption. These effects as
well as decreased weight gain, enlarged liver, and orange urine were
found at 300 mg/kg/day. In this study developmental toxicity was
observed. The developmental LOAEL in rabbits was 150 mg/kg/day, based
on slightly increased resorptions, abnormal cranial development, and
increased sternal variants. In a three-generation rat reproduction
study, the parental NOAEL was 12.5 mg/kg/day. The parental LOAEL was
37.5 mg/kg/day, based on depressed mean body weight gains in males in
all generations. No
[[Page 57085]]
treatment-related effects were noted on reproductive parameters and the
NOAEL was 37.5 mg/kg/day or greater. A 7-month multigeneration bridging
study was conducted with doses equivalent to 0, 8, 20, or 61 mg/kg/day
in the diet of Fischer 344 rats. The parental NOAEL was 20 mg/kg/day.
The parental LOAEL was 61 mg/kg/day, based on increased liver weights.
No treatment-related effects were noted on reproductive parameters and
the reproductive NOAEL was equal to or greater than 61 mg/kg/day.
4. Subchronic toxicity. Ethalfluralin was evaluated in five
subchronic dietary studies which showed NOAELs of 560 ppm in a 3-month
mouse study, 12 mg/kg/day in a 1-year mouse study, 29 mg/kg/day in a 3-
month rat study, 3.9 mg/kg/day in male rats and 4.9 mg/kg/day in female
rats in a 1-year study, and 27.5 mg/kg/day in a 3-month dog study. A
21-day dermal study in rabbits showed no systemic toxicity, while
slight to severe dermal irritation was observed.
5. Chronic toxicity. Ethalfluralin was administered to Fisher 344
rats in the diet for 2 years in combined chronic toxicity and
carcinogenicity replicate studies. The doses were equivalent to 0, 4.2,
10.7, or 32.3 mg/kg/day. The NOAEL for systemic effects was 32.3 mg/kg/
day. Mammary gland fibroadenomas were found in dosed female rats at
statistically significant incidences in the mid and high doses.
Ethalfluralin was administered to B6C3F1 mice in the diet for 2 years
in combined chronic toxicity and carcinogenicity replicate studies. The
doses were equivalent to 0, 10.3, 41.9, or 163.3 mg/kg/day. No
increased incidence of neoplasms was attributed to the treatment. The
NOAEL was 10.3 mg/kg/day. The mid dose (LOAEL) and high dose showed
focal hepatocellular hyperplasia in both sexes. There were increased
relative liver, kidney, and heart weights in females. Some blood
changes were found also, including decreased hematocrit, hemoglobin,
and erythrocyte count accompanied by increased mean corpuscular
hemoglobin concentration in high dose females. Alkaline phosphatase
values were increased at the high dose in both sexes. Body weight gain
decreased at the high dose.
Beagle dogs were given 0, 4, 20, or 80 mg/kg/day orally, by
capsule, for 1-year. The NOAEL was 4 mg/kg/day. The LOAEL was 20 mg/kg/
day, based on increased urinary bilirubin, variations in erythrocyte
morphology, increased thrombocyte count, and increased erythroid series
of the bone marrow. Elevated alkaline phosphatase levels were found at
the two higher doses and siderosis of the liver at the high dose.
EPA's Office of Pesticide Program's Carcinogenicity Peer Review
Committee concluded that ethalfluralin should be classified as Group C,
a possible human carcinogen, based on increased mammary gland
fibroadenomas and adenomas/fibroadenomas combined in female rats. The
tumor incidences were statistically significant at both the mid and
high dose, and exceeded of the upper range of historical controls.
Based on a low dose extrapolation, the Q1 * of 8.9 x
10-2 (mg/kg/day)-1 has been calculated.
6. Animal metabolism. Fischer 344 rats were treated orally with a
single low dose, a single high dose, or repeated low doses of
radiolabeled ethalfluralin. Absorption of ethalfluralin was estimated
at 79-87% of the dose for all dose levels. Ethalfluralin was rapidly
and extensively metabolized, and 95% of the chemical was excreted in
urine and feces by 7 days. The major route of elimination for the
radiolabel was in the feces, 50.9-63.2%, and the levels remaining in
the tissues after 72 hours were negligible. The major metabolites in
urine and feces were identified.
7. Metabolite toxicology. The residue of concern is ethalfluralin
per se, as specified in 40 CFR 180.416. Thus there is no need to
address metabolite toxicity.
8. Endocrine disruption. There is no evidence to suggest that
ethalfluralin has an effect on any endocrine system.
C. Aggregate Exposure
1. Dietary exposure. Acute dietary risk assessments are performed
for a food-use pesticide if a toxicological study has indicated the
possibility of an acute effect of concern occurring as a result of a 1-
day or single exposure. EPA has previously used a NOAEL of 75 mg/kg/day
from a rabbit developmental toxicity study as the toxicity endpoint for
assessing acute dietary risk in females 13-50 years of age. An acute
reference dose (RfD) of 0.75 mg/kg/day was calculated, based on a NOAEL
of 75 mg/kg/day and an uncertainty factor (UF) of 100 (10 for
interspecies extrapolation and 10 for intraspecies variation). EPA has
previously added a 3X FQPA safety factor, resulting in an acute
population adjusted dose (aPAD) of 0.25 mg/kg/day. Likewise, in this
assessment, acute dietary risk to females 13-50 years old was based on
an aPAD of 0.25 mg/kg/day.
Chronic dietary exposure to ethalfluralin is possible due to the
potential presence of ethalfluralin residue in certain foods. Chronic
dietary risk was evaluated using a chronic RfD of 0.04 mg/kg/day, which
is based on a NOAEL of 4 mg/kg/day from a chronic dog study along with
an UF of 100. EPA previously concluded that an FQPA safety factor of 1X
is appropriate for assessing chronic dietary risk.
EPA has concluded that ethalfluralin should be classified as group
C, a possible human carcinogen, based on increased mammary gland
fibroadenomas and adenomas/fibroadenomas combined in female rats.
Therefore, a cancer risk assessment was included. Based on a low dose
extrapolation, the Q1 * of 8.9 x 10-2 (mg/kg/
day)-1 has been calculated and was used in this cancer risk
assessment.
i. Food. The dietary exposure assessment was based on all
commodities with tolerances for ethalfluralin established at 40 CFR
180.416 together with the proposed tolerances of 0.05 ppm each for
canola, dill, and safflower. The dietary exposure evaluation model,
which is produced by Novigen Sciences, Inc. and licensed to Dow
AgroSciences, was used to estimate dietary exposure. This software used
the food consumption data for the 1989-1991 United States Department of
Agriculture Continuing Surveys of Food Intake by Individuals (CSFII
1989-1991).
a. Acute. An acute dietary risk assessment was conducted with the
conservative assumptions of 100% crop treated and tolerance level
residues for all crops. These assumptions result in a very conservative
estimate of human exposure and risk. Acute dietary risk for females 13+
years old was assessed using an aPAD of 0.25 mg/kg/day. Even with
conservative assumptions used in this analysis, acute dietary exposure
was estimated to occupy only 0.05% of the aPAD for females 13+ years
old. Adverse effects are not expected for exposures occupying 100% or
less of the aPAD. Therefore, acute exposure and risk from food is well
within acceptable levels.
b. Chronic. Chronic dietary exposure and risk was estimated with
the conservative assumptions of 100% crop treated and tolerance level
residues for all crops. The estimate of potential chronic exposure and
risk is very conservative and estimated risk would be substantially
reduced with further refinement to the exposure estimate. Even with the
conservative assumptions used in this analysis, chronic exposure is
estimated to occupy only 0.1% of the RfD for the general U.S.
population. Chronic dietary exposure is estimated to occupy 0.4% of the
RfD for non-nursing infants, the population subgroup estimated to have
highest potential exposure. Therefore, chronic exposure
[[Page 57086]]
and risk from food is well within acceptable levels.
c. Cancer. Cancer risk was estimated based on percent crop treated
and anticipated residues as provided in EPA's Reregistration
Eligibility Decision (RED) for ethalfluralin. Exposure to ethalfluralin
from food is estimated to result in a lifetime cancer risk of 7.11 x
10-7. Cancer risks of less than 1 x 10-6 are
generally considered to be negligible.
ii. Drinking water. There are no established maximum contaminant
levels for residues of ethalfluralin in drinking water and health
advisory levels for ethalfluralin have not been established. EPA has
previously used modeling for a screening level assessment of potential
ethalfluralin exposure through drinking water. The Agency has used
EPA's pesticide root zone model/exposure analysis modeling systems and
screening concentrations in ground water to provide a screening level
assessment for surface water and ground water, respectively. Based on
these models, EPA has indicated the estimated environmental
concentrations (EECs) for acute exposures are estimated to be 2.3 parts
per billion (ppb) for surface water and 0.02 ppb for ground water. The
EECs for chronic exposures are estimated to be 0.052 ppb for surface
water and 0.02 ppb for ground water. Estimated concentrations of a
pesticide are compared to a drinking water level of comparison (DWLOC)
as a surrogate estimate of exposure and risk. The DWLOC is the
concentration of a pesticide in drinking water that would be acceptable
as an upper limit in light of total aggregate exposure to that
pesticide.
a. Acute. As indicated previously, EPA has used surface water and
ground water EECs of 2.3 ppb and 0.02 ppb, respectively, for comparison
with the DWLOC in an acute assessment. The DWLOC for acute exposure in
females 13+ years old was based on an aPAD of 0.25 mg/kg/day and was
calculated to be 7,500 ppb. Therefore, the acute DWLOC for
ethalfluralin is over 3,000 fold greater than the EEC for surface water
or ground water, indicating that potential acute exposure and risk from
drinking water is well within acceptable levels.
b. Chronic. As indicated previously, EPA has used surface water and
ground water EECs of 0.052 ppb and 0.02 ppb, respectively, for
comparison with the DWLOC in a chronic assessment. The chronic DWLOC
was calculated based on a chronic RfD of 0.04 mg/kg/day and accounted
for potential chronic exposure to ethalfluralin through residues in
food. The chronic DWLOC for the general U.S. population and non-nursing
infants was calculated to be 1,400 ppb and 400 ppb, respectively.
Therefore, chronic DWLOCs are substantially greater than estimated
residue concentration in surface water or ground water over a chronic
exposure period, indicating that chronic exposure and risk from
drinking water are well with acceptable levels.
c. Cancer. The DWLOC for the cancer risk assessment was calculated
to be 0.12 ppb. Surface water and ground water EECs of 0.052 ppb and
0.02 ppb, respectively, were used for comparison with the DWLOC. The
EECs are below the DWLOC, indicating that the cancer risk would
generally be considered negligible.
2. Non-dietary exposure. Ethalfluralin is not currently registered
for use on any residential non-food sites, and thus, it is not expected
that non-occupational, non-dietary exposures will occur.
D. Cumulative Effects
EPA at this time has not established methodologies to resolve the
complex issues concerning common mechanism of toxicity in a meaningful
way. Although ethalfluralin is a member of the dinitroaniline class of
herbicides, there is no information available, at this time to
determine whether ethalfluralin has a common mechanism of toxicity with
other substances or how to include this pesticide in a cumulative risk
assessment. Based on the metabolic profile, ethalfluralin does not
appear to produce a toxic metabolite produced by other substances.
Therefore, only aggregate exposure and risk were considered.
E. Safety Determination
1. U.S. population. Using conservative exposure assumptions
previously described, chronic dietary exposure to residues of
ethalfluralin from current and proposed uses was estimated to occupy
only 0.1% of the RfD for the general U.S. population. EPA generally has
no concern for exposures below 100% of the RfD since the RfD represents
the level at or below which daily exposure over a lifetime will not
pose appreciable risks to human health. Additionally, the chronic DWLOC
was found to be substantially greater than EECs for ethalfluralin in
surface water or ground water, indicating risk is well within
acceptable levels. Cancer risk resulting from potential exposure to
ethalfluralin through food and drinking water was estimated. Cancer
risk from potential dietary and drinking water exposure for the general
U.S. population was found to be within a range that EPA has generally
considered negligible. Thus, based on the completeness and reliability
of the toxicity data and the conservative exposure assessment, it is
concluded that there is a reasonable certainty that no harm will result
to the general U.S. population from aggregate exposure to ethalfluralin
residues from current and proposed uses.
2. Infants and children. Risk for developmental toxicity from acute
exposure to ethalfluralin was evaluated for females 13+ years old. As
indicated in the previous discussion, risk from aggregate acute
exposure to ethalfluralin through food and drinking water is well
within acceptable levels. It can be concluded that there is a
reasonable certainty that no harm will result for both females 13+
years old, and for the prenatal development of infants, from aggregate
acute exposure to ethalfluralin.
Chronic aggregate exposure and risk was evaluated for non-nursing
infants, the population subgroup predicted to be most highly exposed.
As indicated previously, risk from aggregate chronic exposure through
food and drinking water is well within acceptable levels. Thus, based
on the completeness and reliability of the toxicity data and the
conservative exposure assessment, it can be concluded with reasonable
certainty that no harm will result to infants and children from chronic
aggregate exposure to ethalfluralin based on current and proposed uses.
F. International Tolerances
There are no Codex, Canadian or Mexican maximum residue limits
established for ethalfluralin.
[FR Doc. 01-28198 Filed 11-13-01; 8:45 am]
BILLING CODE 6560-50-S