carfentrazone-ethyl Pesticide Petition Filing 4/01
ENVIRONMENTAL PROTECTION AGENCY
Notice of Filing a Pesticide Petition to Establish a Tolerance
for a Certain Pesticide Chemical in or on Food
AGENCY: Environmental Protection Agency (EPA).
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-1014, must be
received on or before May 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-1014 in the subject line on the first page of your
FOR FURTHER INFORMATION CONTACT: By mail: Joanne Miller, Registration
Division (7505C), Office of Pesticide Programs, Environmental
Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460;
telephone number: (703) 305-6224; e-mail address:
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:
Categories NAICS codes potentially
Industry 111 Crop production
112 Animal production
311 Food manufacturing
This listing is not intended to be exhaustive, but rather provides
a guide for readers regarding entities likely to be 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
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'' 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-1014. 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-1014 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: email@example.com, 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-1014. 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
E. What Should I Consider as I Prepare My Comments for EPA?
You may find the following suggestions helpful for preparing your
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
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
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 Comestic 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
List of Subjects
Environmental protection, Agricultural commodities, Feed additives,
Food additives, Pesticides and pests, Reporting and recordkeeping
Dated: April 3, 2001.
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 view 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.
EPA has received a pesticide petition (PP 7F4795) from FMC
Corporation, Agricultural Products Group, 1735 Market Street,
Philadelphia, PA 19103 proposing, pursuant to section 408(d) of the
FFDCA, 21 U.S.C. 346a(d), to amend 40 CFR part 180 by establishing a
tolerance for residues of carfentrazone-ethyl (ethyl--2-
triazol-1-yl]-4-fluorobenzene-propanoate) and the metabolite
carfentrazone-ethyl chloropropionic acid (, 2-dichloro-5[-4-
fluorobenzenepropanoic acid) in or on the raw agricultural commodity
(RAC) cotton at 3.5 parts per million (ppm). EPA has determined that
the petition contains 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. The metabolism of carfentrazone-ethyl in
plants is adequately understood. Corn, wheat, and soybean metabolism
studies with carfentrazone-ethyl have shown uptake of material into
plant tissue with no significant movement into grain or seeds. All
three plants extensively metabolized carfentrazone-ethyl and exhibited
a similar metabolic pathway. The residues of concern are the combined
residues of carfentrazone-ethyl and carfentrazone-ethyl-
2. Analytical method. There is a practical analytical method for
detecting and measuring levels of carfentrazone and its metabolites in
or on food with a limit of quantitation (LOQ) that allows monitoring of
food with residues at or above the levels set in the tolerances. The
analytical method for carfentrazone-ethyl involves separate analyses
for parent and its metabolites. The parent is analyzed by gas
chromatography/electron capture detector (GC/ECD). The metabolites are
derivatized with boron trifluoride and acetic anhydride for analysis by
gas chromatography/mass spectrometry detector (GC/MSD) using selective
3. Magnitude of residues. Carfentrazone-ethyl 40 DF or 2EC was
applied (early soil and late foliar applications) to 13 cotton trials
in the appropriate EPA regions. The RACs were harvested at the
appropriate growth stages and subsequent analyses determined that the
residues of carfentrazone-ethyl and its metabolites would not exceed
the proposed tolerances of 3.5 ppm in or on cotton gin byproduct and
0.2 ppm in or on cottonseed (undelinted).
B. Toxicological Profile
1. Acute toxicity. Carfentrazone-ethyl demonstrates low oral,
dermal and inhalation toxicity. The acute oral LD50 value in
the rat was greater than 5,000 milligrams/kilograms (mg/kg), the acute
dermal LD50 value in the rat was greater than 4,000 mg/kg
and the acute inhalation LC50 value in the rat was greater
than 5.09 milligrams/Liter (mg/L)/4h. Carfentrazone-ethyl is non-
irritating to rabbit skin and minimally irritating to rabbit eyes. It
did not cause skin sensitization in guinea pigs. An acute neurotoxicity
study in the rat had a systemic no observed adverse effect level
(NOAEL) of 500 mg/kg based on clinical signs and decreased motor
activity levels; the NOAEL for neurotoxicity was greater than 2,000 mg/
kg highest dose tested (HDT) based on the lack of neurotoxic clinical
signs or effects on neuropathology.
2. Genotoxicty. Carfentrazone-ethyl did not cause mutations in the
Ames assay with or without metabolic activation. There was a positive
response in the chromosome aberration assay without activation but a
negative response with activation. The mouse micronucleus assay (an in
vivo test which also measures chromosome damage), the chinese hampster
ovary/hypoxanthine guanine phophoribosyl transferase (CHO/HGPRT)
forward mutation assay and the unscheduled DNA synthesis (UDS) assay
were negative. The overwhelming weight of the evidence supports the
conclusion that carfentrazone-ethyl is not genotoxic.
3. Reproductive and developmental toxicity. Carfentrazone-ethyl is
not considered to be a reproductive or a developmental toxin. In the 2-
generation reproduction study, the NOAEL for reproductive toxicity was
greater than 4,000 ppm; (greater than 323, greater than 409 mg/kg/day).
In the developmental toxicity studies, the rat and rabbit maternal
NOAELs were 100 mg/kg/day and 150 mg/kg/day, respectively. The
developmental NOAEL for the rabbit was greater than 300 mg/kg/day,
which was the HDT and for the rat the NOAEL was 600 mg/kg/day based on
increased litter incidences of thickened and wavy ribs at 1,250 mg/kg/
day. These two findings (thickened and wavy ribs) are not considered
adverse effects of treatment but related delays in rib development
which are generally believed to be reversible.
4. Subchronic toxicity. Ninety-day feeding studies were conducted
in mice, rats and dogs with carfentrazone-ethyl. The NOAEL for the
mouse study was 4,000 ppm (571 mg/kg/day), the rat study was 1,000 ppm
(57.9 mg/kg/day for males; 72.4 mg/kg/day for females) and for dogs was
150 mg/kg/day. A 90-day subchronic neurotoxicity study in the rat had a
systemic NOAEL of 1,000 ppm (59.0 mg/kg/day for males; 70.7 mg/kg/day
for females) based on decreases in body weights (bwt), body weight
gains and food consumption at 10,000 ppm; the neurotoxicity NOAEL was
greater than 20,000 ppm (1,178.3 mg/kg/day for males; 1,433.5 mg/kg/day
for females) which was the highest dose tested.
5. Chronic toxicity. Carfentrazone-ethyl is not carcinogenic to
rats or mice. A 2-year combined chronic toxicity/oncogenicity study in
the rat was negative for carcinogenicity and had a chronic toxicity
NOAEL of 200 ppm (9 mg/kg/day) for males and 50 ppm (3 mg/kg/day) for
females based on red fluorescent granules consistent with porphyrin
deposits in the liver at the 500 and 200 ppm levels, respectively. An
18-month oncogenicity study in the mouse had a carcinogenic NOAEL that
was greater than 7,000 ppm (>1,090 mg/kg/day for males; >1,296 mg/kg/
day for females) based on, no evidence of carcinogenicity at the
highest dose tested. A 1-year oral toxicity study in the dog had a
NOAEL of 50 mg/kg/day based on isolated increases in urine porphyrins
in the 150 mg/kg/day group (this finding was not considered adverse).
Using the guidelines for carcinogen risk assessment, carfentrazone-
ethyl should be classified as Group ``E'' for carcinogenicity--no
evidence of carcinogenicity--based on the results of carcinogenicity
studies in two species. There was no evidence of carcinogenicity in an
18-month feeding study in mice and a 2-year feeding study in rats at
the dosage levels tested. The doses tested are adequate for identifying
a cancer risk. Thus, a cancer risk assessment is not necessary.
6. Animal metabolism. The metabolism of carfentrazone-ethyl in
animals is adequately understood. Carfentrazone-ethyl was extensively
metabolized and readily eliminated following oral administration to
rats, goats, and poultry via excreta. All three animals exhibited a
similar metabolic pathway. As in plants, the parent chemical was
metabolized by hydrolytic mechanisms to predominantly form
carfentrazone-ethyl-chloropropionic acid, which was readily excreted.
7. Endocrine disruption. An evaluation of the potential effects on
the endocrine systems of mammals has not been determined; however, no
evidence of such effects was reported in the chronic or reproductive
toxicology studies described above. There was no observed pathology of
the endocrine organs in these studies. There is no evidence at this
time that carfentrazone-ethyl causes endocrine effect.
C. Aggregate Exposure
1. Dietary exposure--i. Acute dietary. Based on the available
toxicity data, EPA has established an acute reference dose (RfD) for
carfentrazone-ethyl of 5 mg/kg/day. The RfD for carfentrazone-ethyl is
based on acute neurotoxicity study in rats with a threshold NOAEL of
500 mg/kg/day and an uncertainty factor (UF) of 100.
ii. Chronic dietary. Based on the available toxicity data, EPA has
established a RfD for carfentrazone-ethyl of 0.03 mg/kg/day. The RfD
for carfentrazone-ethyl is based on a 2-year chronic toxicity/
carcinogenicity study in rats with a threshold NOAEL of 3 mg/kg/day and
an UF of 100. For purposes of assessing the potential chronic dietary
exposure, a Tier 1 dietary risk assessment was conducted based on the
theoretical maximum residue contribution (TMRC) from the established
and proposed tolerances for carfentrazone-ethyl. The tolerances are as
0.1 ppm in or on grain.
0.3 ppm in or on hay.
0.2 ppm in or on straw.
1.0 ppm in or on cereal grain forage (except corn and
0.1 ppm in or on sorghum and corn (sweet and field)
0.15 ppm in or on stover.
0.1 ppm in or on sweet corn, K + CWHR (kernels plus cob
with husk removed), in or on the RAC soybeans.
At 0.1 ppm in or on soybean seed, in or on the RAC cotton.
At 3.5 ppm in or on cotton gin byproducts.
0.2 ppm in or on cottonseed (undelinted).
The TMRC is a ``worse case'' estimate of dietary exposure since it
is assumed that 100% of all crops for which tolerances are established
are treated and that pesticide residues are present at the tolerance
levels. In conducting this exposure assessment, the following very
conservative assumptions were made--100% of soybeans, cotton, and
cereal grains will contain carfentrazone-ethyl residues and those
residues would be at the level of the tolerance which result in an
overestimate of human exposure.
i. Food. Dietary exposure from the proposed uses would account for
0.1% or less of the RfD in subpopulations (including infants and
children). Dietary exposure from the proposed uses would account for
3.2% or less of the RfD in subpopulations (including infants and
ii. Drinking water. Studies have indicated that carfentrazone-ethyl
will not move into ground water, therefore water has not been included
in the dietary risk assessment.
2. Non-dietary exposure. No specific worker exposure tests have
been conducted with carfentrazone-ethyl. The potential for non-
occupational exposure to the general population has not been fully
assessed. No specific worker exposure tests have been conducted with
D. Cumulative Effects
EPA is also required to consider the potential for cumulative
effects of carfentrazone-ethyl and other substances that have a common
mechanism of toxicity. EPA consideration of a common mechanism of
toxicity is not appropriate at this time since EPA does not have
information to indicate that toxic effects produced by carfentrazone-
ethyl would be cumulative with those of any other chemical compounds;
thus only the potential risks of carfentrazone-ethyl are considered in
this exposure assessment.
E. Safety Determination
1. U.S. population. Using the conservative exposure assumptions
described and based on the completeness and reliability of the toxicity
data, the aggregate exposure to carfentrazone-ethyl will utilize 0.06%
of the RfD and 1.4% of the RfD for the United States population. EPA
generally has no concern for exposures below 100% of the RfD.
Therefore, based on the completeness and reliability of the toxicity
data and the conservative exposure assessment, there is a reasonable
certainty that no harm will result from aggregate exposure to residues
of carfentrazone-ethyl, including all anticipated dietary exposure and
all other non-occupational exposures.
2. Infants and children. In assessing the potential for additional
sensitivity of infants and children to residues of carfentrazone-ethyl,
EPA considers data from developmental toxicity studies in the rat and
rabbit and the 2-generation reproduction study in the rat. The
developmental toxicity studies are designed to evaluate adverse effects
on the developing organism resulting from pesticide exposure during
prenatal development. Reproduction studies provide information relating
to effects on the reproductive capacity of males and females exposed to
the pesticide. Developmental toxicity was not observed in developmental
toxicity studies using rats and rabbits. In these studies, the rat and
rabbit maternal NOAELs were 100 mg/kg/day and 150 mg/kg/day,
respectively. The developmental NOAEL for the rabbit was greater than
300 mg/kg/day, which was the HDT and for the rat was 600 mg/kg/day
based on increased litter incidences of thickened and wavy ribs. These
two findings are not considered adverse effects of treatment but
related delays in rib development, which are generally believed to be
In a 2-generation reproduction study in rats, no reproductive
toxicity was observed under the conditions of the study at 4,000 ppm,
which was the HDT.
FFDCA section 408 provides that EPA may apply an additional safety
factor for infants and children in the case of threshold effects to
account for prenatal and postnatal toxicity and the completeness of the
data base. Based on the current toxicological data requirements, the
data base relative to prenatal and postnatal effects for children is
complete and an additional
UF is not warranted. Therefore at this time, the RfD of 0.03 mg/kg/day
is appropriate for assessing aggregate risk to infants and children.
Reference dose. Using the conservative exposure assumptions
described above, the percent of the RfD that will be utilized by
aggregate exposure to residues of carfentrazone-ethyl for non-nursing
infants (<1 year old) would be 0.08% RfD and 3.0% RfD; for children 1
to 6 years of age would be 0.08% RfD and 3.2% RfD, (the most highly
exposed group). Based on the completeness and reliability of the
toxicity data and the conservative exposure assessment, there is a
reasonable certainty that no harm will result to infants and children
from aggregate exposure to the residues of carfentrazone-ethyl
including all anticipated dietary exposure.
F. International Tolerances
There are no Codex Alimentarius Commission (Codex) maximum residue
levels (MRLs) for carfentrazone-ethyl on any crops at this time.
However, MRLs for small grains in Europe have been proposed which
consist of carfentrazone-ethyl and carfentrazone-ethyl-chloropropionic
[FR Doc. 01-9060 Filed 4-11-01; 8:45 am]