[Federal Register: June 29, 2005 (Volume 70, Number 124)]
[Notices]
[Page 37397-37403]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr29jn05-65]
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ENVIRONMENTAL PROTECTION AGENCY
[OPP-2005-0033; FRL-7718-8]
Paraquat Dichloride; Notice of Filing a Pesticide Petition to
Establish a Tolerance for a Certain Pesticide Chemical in or on Food
AGENCY: Environmental Potection 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 identification (ID) number OPP-
2005-0033, must be received on or before July 29, 2005.
ADDRESSES: Comments may be submitted electronically, by mail, or
through hand delivery/courier. Follow the detailed instructions as
provided in Unit I of the SUPPLEMENTARY INFORMATION.
FOR FURTHER INFORMATION CONTACT: Jim Tompkins, Registration Division
(7505C), Office of Pesticide Programs, Environmental Protection Agency,
1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone
number:(703) 305-5697; e-mail address: tompkins.jim@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
[[Page 37398]]
pesticide manufacturer. Potentially affected entities may include, but
are not limited to:
Crop production (NAICS 111)
Animal production (NAICS 112)
Food manufacturing (NAICS 311)
Pesticide manufacturing (NAICS 32532)
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 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 Get Copies of this Document and Other Related Information?
1. Docket. EPA has established an official public docket for this
action under docket ID number OPP-2005-0033. The official public docket
consists of the documents specifically referenced in this action, any
public comments received, and other information related to this action.
Although a part of the official docket, the public docket does not
include Confidential Business Information (CBI) or other information
whose disclosure is restricted by statute. The official public docket
is the collection of materials that is available for public viewing at
the Public Information and Records Integrity Branch (PIRIB), Rm. 119,
Crystal Mall 2, 1801 S. Bell St., Arlington, VA. This docket
facility is open from 8:30 a.m. to 4 p.m., Monday through Friday,
excluding legal holidays. The docket telephone number is (703) 305-
5805.
2. Electronic access. You may access this Federal Register document
electronically through the EPA Internet under the ``Federal Register''
listings at http://www.epa.gov/fedrgstr/.
An electronic version of the public docket is available through
EPA's electronic public docket and comment system, EPA Dockets. You may
use EPA Dockets at http://www.epa.gov/edocket/ to submit or view public
comments, access the index listing of the contents of the official
public docket, and to access those documents in the public docket that
are available electronically. Although not all docket materials may be
available electronically, you may still access any of the publicly
available docket materials through the docket facility identified in
Unit I.B.1. Once in the system, select ``search,'' then key in the
appropriate docket ID number.
Certain types of information will not be placed in the EPA Dockets.
Information claimed as CBI and other information whose disclosure is
restricted by statute, which is not included in the official public
docket, will not be available for public viewing in EPA's electronic
public docket. EPA's policy is that copyrighted material will not be
placed in EPA's electronic public docket but will be available only in
printed, paper form in the official public docket. To the extent
feasible, publicly available docket materials will be made available in
EPA's electronic public docket. When a document is selected from the
index list in EPA Dockets, the system will identify whether the
document is available for viewing in EPA's electronic public docket.
Although not all docket materials may be available electronically, you
may still access any of the publicly available docket materials through
the docket facility identified in Unit I.B. EPA intends to work toward
providing electronic access to all of the publicly available docket
materials through EPA's electronic public docket.
For public commenters, it is important to note that EPA's policy is
that public comments, whether submitted electronically or in paper,
will be made available for public viewing in EPA's electronic public
docket as EPA receives them and without change, unless the comment
contains copyrighted material, CBI, or other information whose
disclosure is restricted by statute. When EPA identifies a comment
containing copyrighted material, EPA will provide a reference to that
material in the version of the comment that is placed in EPA's
electronic public docket. The entire printed comment, including the
copyrighted material, will be available in the public docket.
Public comments submitted on computer disks that are mailed or
delivered to the docket will be transferred to EPA's electronic public
docket. Public comments that are mailed or delivered to the docket will
be scanned and placed in EPA's electronic public docket. Where
practical, physical objects will be photographed, and the photograph
will be placed in EPA's electronic public docket along with a brief
description written by the docket staff.
C. How and To Whom Do I Submit Comments?
You may submit comments electronically, by mail, or through hand
delivery/courier. To ensure proper receipt by EPA, identify the
appropriate docket ID number in the subject line on the first page of
your comment. Please ensure that your comments are submitted within the
specified comment period. Comments received after the close of the
comment period will be marked ``late.'' EPA is not required to consider
these late comments. If you wish to submit CBI or information that is
otherwise protected by statute, please follow the instructions in Unit
I.D. Do not use EPA Dockets or e-mail to submit CBI or information
protected by statute.
1. Electronically. If you submit an electronic comment as
prescribed in this unit, EPA recommends that you include your name,
mailing address, and an e-mail address or other contact information in
the body of your comment. Also include this contact information on the
outside of any disk or CD ROM you submit, and in any cover letter
accompanying the disk or CD ROM. This ensures that you can be
identified as the submitter of the comment and allows EPA to contact
you in case EPA cannot read your comment due to technical difficulties
or needs further information on the substance of your comment. EPA's
policy is that EPA will not edit your comment, and any identifying or
contact information provided in the body of a comment will be included
as part of the comment that is placed in the official public docket,
and made available in EPA's electronic public docket. If EPA cannot
read your comment due to technical difficulties and cannot contact you
for clarification, EPA may not be able to consider your comment.
i. EPA Dockets. Your use of EPA's electronic public docket to
submit comments to EPA electronically is EPA's preferred method for
receiving comments. Go directly to EPA Dockets at http://www.epa.gov/edocket/
, and follow the online instructions for submitting comments.
Once in the system, select ``search,'' and then key in docket ID number
OPP-2005-0033. The system is an `` anonymous access'' system, which
means EPA will not know your identity, e-mail address, or other contact
information unless you provide it in the body of your comment.
ii. E-mail. Comments may be sent by e-mail to opp-docket@epa.gov,
Attention: Docket ID Number OPP-2005-0033. In contrast to EPA's
electronic public docket, EPA's e-mail system is not an ``anonymous
access'' system. If you send an e-mail comment directly to the docket
without going through EPA's electronic public docket, EPA's e-mail
system automatically captures your e-mail address. E-mail addresses
that are automatically
[[Page 37399]]
captured by EPA's e-mail system are included as part of the comment
that is placed in the official public docket, and made available in
EPA's electronic public docket.
iii. Disk or CD ROM. You may submit comments on a disk or CD ROM
that you mail to the mailing address identified in Unit I.C.2. These
electronic submissions will be accepted in WordPerfect or ASCII file
format. Avoid the use of special characters and any form of encryption.
2. By mail. Send your comments to: Public Information and Records
Integrity Branch (PIRIB) (7502C), Office of Pesticide Programs (OPP),
Environmental Protection Agency, 1200 Pennsylvania Ave., NW.,
Washington, DC 20460-0001, Attention: Docket ID Number OPP-2005-0033.
3. By hand delivery or courier. Deliver your comments to: Public
Information and Records Integrity Branch (PIRIB), Office of Pesticide
Programs (OPP), Environmental Protection Agency, Rm. 119, Crystal Mall
2, 1801 S. Bell St., Arlington, VA, Attention: Docket ID
Number OPP-2005-0033. Such deliveries are only accepted during the
docket's normal hours of operation as identified in Unit I.B.1.
D. How Should I Submit CBI to the Agency?
Do not submit information that you consider to be CBI
electronically through EPA's electronic public docket or by e-mail. You
may claim information that you submit to EPA as CBI by marking any part
or all of that information as CBI (if you submit CBI on disk or CD ROM,
mark the outside of the disk or CD ROM as CBI and then identify
electronically within the disk or CD ROM the specific information that
is 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 docket and EPA's electronic public docket. If you submit
the copy that does not contain CBI on disk or CD ROM, mark the outside
of the disk or CD ROM clearly that it does not contain CBI. Information
not marked as CBI will be included in the public docket and EPA's
electronic public docket without prior notice. If you have any
questions about CBI or the procedures for claiming CBI, please consult
the person listed 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 a 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
ID 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 FFDCA 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: June 10, 2005.
Betty Shackleford,
Acting Director, Registration Division, Office of Pesticide Programs.
Summary of Petition
The petitioner summary of the pesticide petition is printed below
as required by FFDCA section 408(d)(3). The summary of the petition was
prepared by the petitioner and represents the view of the petitioner.
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.
Syngenta Crop Protection, Inc.
PP 2F6433 , 3E 6763, 1E 6332, 1E 6319, 1E 6223
EPA has received pesticide petitions (2F6433, 3E6763, 1E6332,
1E6319, and 1E6223) from Syngenta Crop Protection, Inc., P.O. Box
18300, Greensboro, NC 27419-8300 and Interregional Research
Project4 (IR4), 681 US Highway 1 South, New
Brunswick, NJ 08902-3390 proposing, pursuant to section 408(d) of the
Federal Food, Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 346a(d), to
amend 40 CFR part 180 by establishing a tolerance for residues of
paraquat dichloride in or on the raw agricultural commodities: cotton,
seed at 5.0 parts per million (ppm); cotton gin byproducts at 82.0 ppm;
soybean, seed at 0.70 ppm; soybean, forage at 0.40 ppm; soybean, hay at
6.0 ppm; soybean, aspirated grain fractions at 60.0 ppm; wheat, grain
at 1.5 ppm; wheat, forage at 0.40 ppm; wheat, hay at 3.0 ppm; wheat,
straw at 40.0 ppm; wheat, aspirated grain fractions at 65.0 ppm;
barley, hay at 3.0 ppm; vegetable, brassica leafy, group at 0.05 ppm;
fruit, pome, group at 0.05 ppm; fruit, stone, group at 0.05 ppm; berry
group at 0.05 ppm; animal feed, nongrass, group at 5.0 ppm; vegetable,
legume, edible-podded, subgroup at 0.05 ppm; pea and bean, succulent,
shelled, subgroup at 0.05 ppm; pea and bean, dried, shelled, except
soybean, subgroup at 0.3 ppm; grape at 0.05 ppm; cranberry at 0.05 ppm;
barley, straw at 1.0 ppm; beet, sugar, tops at 0.05 ppm; sorghum,
forage at 0.1 ppm; hops, cone, dry at 0.5 ppm; cattle, kidney at 0.3
ppm; goat, kidney at 0.3 ppm; hog, kidney at 0.3 ppm; horse, kidney at
0.3 ppm; sheep, kidney at 0.3 ppm; vegetable, fruiting, group at 0.05
ppm; vegetable, cucurbit, group at 0.05 ppm; nut, tree, group at 0.05
ppm; ginger at 0.1 ppm, okra at 0.05 ppm, tanier at 0.05 ppm, and onion
(dry bulb) at 0.1 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
supports granting of the petition. Additional data may be needed before
EPA rules on the petition.
A. Residue Chemistry
1. Plant metabolism. The qualitative nature of the residue in
plants is adequately understood based on studies depicting the
metabolism of paraquat
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dichloride in carrots and lettuce following preemergence treatments and
in potatoes and soybeans following desiccant treatment. The residue of
concern in plants is the parent, paraquat dichloride; the current
tolerance expression for plant commodities, as defined in 40 CFR
180.205(a) and (b).
2. Analytical method. An adequate analytical method (spectrometric
method) has been accepted and published in The Pesticide Analytical
Manual (PAM Vol. II) for the enforcement of tolerances in plant
commodities.
3. Magnitude of residues--i. Cotton. As required under
reregistration, residue studies (MRID No. 44432402) were conducted to
determine the levels of paraquat cation on ginned cotton seed and
cotton byproducts. Twelve residue field trials were conducted during
1995 in the United States. This data reflects a use pattern of a total
of 3 lbs ai/A per season as preemergence; followed by two post-directed
applications with shielded/hooded sprayers; followed by three broadcast
defoliation/desiccation applications. Paraquat dichloride residues in
cotton seed ranged from < 0.05 to 4.6 mg/kg. These data support a cotton
seed tolerance of 5.0 ppm and a gin byproducts tolerance of 82.0 ppm
with a 3 day PHI.
ii. Wheat. As required under reregistration, residue studies (MRID
No. 44965703) were conducted to determine levels of paraquat cation in
or on wheat grain, forage, hay, straw, and aspirated grain fractions.
Twenty-two residue trials were conducted on wheat (nine on spring wheat
and thirteen on winter wheat) during 1997 and 1998. This data reflects
a use pattern (preemergence/broadcast, prior to heading/spot spray and
three days before grain and straw harvest/broadcast for a total of 1.75
lbs. ai/A. The range of paraquat dichloride residues was: wheat grain
(0.06 to 1.1 ppm), wheat forage (< 0.050 to 0.29 ppm), wheat hay (< 0.050
to 2.8 ppm), wheat straw (4.0 to 40 ppm), and aspirated grain fractions
(40 to 61 ppm). These data support a revised tolerance for grain of 1.5
ppm, forage of 0.4 ppm, hay of 3.0 ppm, straw of 40 ppm, and aspirated
grain fractions of 65 ppm.
iii. Soybean. As required under reregistration, residue studies
(MRID No. 44965702) were conducted to determine levels of paraquat
cation on soybean seed, forage, hay, and aspirated grain fractions
(MRID No. 44965701). Twenty-two field residue studies were conducted on
soybeans during 1997 and 1998. The aspirated grain fractions study was
conducted during 1995 at 12X the label rate two days prior to harvest.
The 1997-1998 data reflects a use pattern (preemergence, directed
spray, spot spray, and three days before harvest for a total seasonal
rate of 2.9 lbs. ai/A. The range of paraquat dichloride residues was:
soybean seed (< 0.05 to 0.69 ppm), soybean hay (< 0.05 to 5.65 ppm),
soybean forage (< 0.05to 0.38 ppm), and aspirated grain fractions (57
ppm based on calculations presented in MRID No. 44965701). These data
support a revised tolerance for soybean seed at 0.7 ppm, hay at 6.0
ppm, forage at 0.4 ppm and aspirated grain fractions at 60 ppm.
iv. Ginger. As required under reregistration, residue studies,
residue studies were conducted to determine levels of paraquat cation
on ginger. Data was collected from three field studies in Hawaii. All
samples from these studies showed residues less than 0.1 ppm.
v. Okra. As required under reregistration, residue studies were
conducted to determine levels of paraquat cation on okra. Trials were
conducted in South Carolina, Tennessee and Texas. No quatifiable
residues were found in any of the samples.
vi. Onion (dry bulb). There is an established tolerance for pre-
plant and preemergence applications of paraquat dichloride. Several
states appealed to IR4 to request a tolerance for post-directed
applications in onion (dry bulb). Field trials were conducted in New
York, Texas, Ohio, Washington, California and Colorado. No quatifiable
residues were observed in any of the samples.
vii. Tanier. As required under reregistration, residue studies were
conducted to determine levels of paraquat cation on tanier. There is an
existing tolerance for tanier for Puerto Rico only. Data was collected
from one field trial in Florida. No quantifiable residues were observed
in any of the samples.
The 1997 Paraquat Dichloride Reregistration Eligibility Decision
(RED) indicates that crop group tolerances will be established and
indicates the tolerance levels (0.05 ppm) for vegetable, brassica
leafy, group; fruit, pome group; fruit, stone, group; and berry group.
These are based on existing tolerances. New grape (0.05 ppm) and
cranberry (0.05 ppm) tolerances are proposed as they were part of the
small fruit group which is being changed to berry group. The request
for animal feed, nongrass, group tolerance is also based on statements
in the RED to group alfalfa, clover, and birdsfoot trefoil existing
tolerances (these are based on broadcast preemergence uses). The RED
indicates that tolerances should be raised for forage (75 ppm) and hay
(210 ppm). These tolerances are not being proposed as they appear to be
based on harvest aid uses in clover and birdsfoot trefoil which are not
relevant as only the broadcast preemergence uses are desired in these
crops. The field residue data for preemergence broadcast uses in
alfalfa, clover and birdsfoot trefoil supports the existing tolerance
of 5 ppm. The only harvest aid use for crops in this group is for use
on alfalfa grown for seed which has a grazing and feeding prohibition.
Proposed tolerance for barley, straw (1.0 ppm) is a new tolerance
indicated in the RED assessment. Proposed individual (miscellaneous)
tolerance changes based on the RED assessment include beet, sugar, tops
(0.05 ppm); sorghum, forage (0.1ppm); and hops, cone, dry (0.5 ppm).
The proposed increased tolerances for kidney are to harmonize U. S.
tolerances with Codex Maximum Residue Levels (MRL's) as discussed in
the RED. Proposed tolerances for vegetable, fruiting, group; vegetable,
cucurbit, group, and nut, tree, group update the crop group
nomenclature only. They are based on existing crop group tolerances.
The proposed tolerances for Crop Subgroups 6A, 6B, and 6C (Peas and
Beans) are not discussed in the RED and result from a new tolerance
(peas, dry) granted in Sept. 1991. The use pattern for Group 6C is for
a harvest aid application while 6A and 6B are for preplant/preemergence
application.
Tolerances discussed in the RED which are not being requested
include: grape, juice (the processing factor is 1.0 so the tolerance is
the same as grape), raisin (processing factor is 1.0), pineapple,
process residue (the processing factor is 0.6), sugarcane molasses
(processing factor is 0.1 for refined molasses) and corn, field, flour
(processing factor is 1.0, discussed in the Sept. 1991 FR Notice).
Animal feed, grass, group will not be requested. Syngenta Crop
Protection, Inc. is voluntarily removing animal feed, grass (pasture
and range) uses from the label except for grasses grown for seed and
``juniper leaf moisture reduction or desiccation prior to prescribed
burning of pastures'' which have a feeding/grazing prohibition.
B. Toxicological Profile
1. Acute toxicity. Acute toxicity studies conducted with the 45.6%
paraquat dichloride technical concentrate give the following results:
oral LD50 in the rat of 344 mg/kg (males) and 283 mg/kg
(females) (Category II); dermal LD50 in the rat of >2,000
mg/kg for males and females (Category III); the primary eye irritation
study showed
[[Page 37401]]
corneal involvement with clearing in 17 days (Category II) ; and dermal
irritation of slight erythema and edema at 72 hours (Category IV).
Paraquat dichloride is not a dermal sensitizer. Acute inhalation
studies conducted to EPA guideline with aerosolized sprays result in
LC50 of 0.6 to 1.4 [mu]g paraquat cation/L (Category I).
However, since paraquat dichloride has no measurable vapor pressure,
and hydraulic spray droplets are too large to be respired, inhalation
exposure is not a concern in practice.
2. Genotoxicity. Paraquat dichloride was not mutagenic in the Ames
test using Salmonella typhimurium strains TA1535, TA1538, TA98, and
TA100; the chromosomal aberrations in the bone marrow test system; or
in the dominant lethal mutagenicity study with CD-1 mice. Additionally,
paraquat dichloride was negative for unscheduled DNA synthesis in rat
hepatocyctes in vitro and in vivo. Paraquat dichloride was weakly
positive in the mouse lymphoma cell assay only in the presence of
metabolic activation. Paraquat dichloride was weakly positive in
mammalian cells (lymphocytes) and positive in the sister chromatid
exchange (SCE) assay in Chinese hamster lung fibroblasts. Paraquat
dichloride is nonmutagenic.
3.Reproductive and developmental toxicity. A three-generation
reproduction study in rats fed diets containing 0, 25, 75, and 150 ppm
(0, 1.25, 3.75, or 7.5 mg of paraquat cation/kg/day, respectively)
showed no effect on body weight gain, food consumption and utilization,
fertility and length of gestation of the F0, F1, and F2 parents at any
dose. The no observed effect level (NOEL) and lowest observed effect
level (LOEL) for systemic toxicity are 25 ppm (1.25 mg/kg/day) and 75
ppm (3.75 mg/kg/day), respectively, expressed as paraquat cation, based
on high mortality due to lung damage (alveolar histiocytes). The NOEL
for reproductive toxicity is less than or equal to 150 ppm [7.5 mg/kg/
day; highest dose tested (HDT)] expressed as paraquat cation, as there
were no reproductive effects.
Two developmental toxicity studies were conducted in rats given
gavage doses of 0, 1, 5, and 10 mg/kg/day and 0, 1, 3, and 8 mg/kg/day,
respectively, expressed as paraquat cation. In the first study, the
NOEL for maternal toxicity was 1 mg/kg/day based on clinical signs of
toxicity and decreased body weight gain at 5 mg/kg/day (the LOEL). The
NOEL for developmental toxicity was set at 5 mg/kg/day based on delayed
ossification of the forelimb and hindlimb digits. In the second study,
the maternal and developmental NOEL is 8 mg/kg/day (HDT) as there were
no effects observed at any dose level even though the animals were
examined more carefully in the manus and pes assessment. Based on both
studies the overall NOEL for maternal and developmental toxicity is at
least 3 mg/kg/day.
The developmental toxicity studies were conducted in mice given
gavage doses of 0, 1, 5, and 10 mg/kg/day and 0, 7.5, 15, or 25 mg/kg/
day paraquat ion, respectively. In the first study the NOEL and LOEL
for maternal toxicity are 5 mg/kg/day and 10 mg/kg/day, respectively,
based on reductions in body weight gain and death (range-finding
study). The NOEL and LOEL for developmental toxicity are 5 mg/kg/day
and 10 ma/kg/day, respectively, based on an increased number of litters
and fetuses with partial ossification of the 4thsternebrae
at 10 mg/kg/day (HDT). Both the maternal and developmental NOELs are at
15 mg/kg/day in the second study. The maternal LOEL of 25 mg paraquat
cation/kg/day is based on death, decreases in body weight and body
weight gain, and mean fetal weights, retarded ossification and other
skeletal effects. The developmental/maternal NOEL should be based on
the second study and is 15 mg/kg/day. Paraquat dichloride is not a
developmental toxin.
4. Subchronic toxicity.A 90 day feeding study in dogs fed doses of
0, 7, 20, 60, or 120 ppm with a NOEL of 20 ppm (equivalent to 0.56 mg
paraquat cation/kg/d for males and 0.71 mg paraquat cation/kg/d for
females) based on lung effects such as alveolitis and alveolar collaps
seen at the LOEL of 60 ppm.
A 21 day dermal toxicity study in which rabbits were exposed
dermally to doses of 0, 1.5, 3.4, 7.8, or 17.9 mg/kg/day resulted in a
NOEL of 1.15 mg paraquat cation/kg.day and a LOEL of 2.6 mg paraquat
cation/kg/day based on dermal irritation.
A 21 day inhalation toxicity study in rats that were exposed to
respirable aerosols of paraquat at doses of 0, 0.01, 0.1, 0.5, and 1.0
q/L with a NOEL of 0.01 ug paraquat cation/L and a LOEL of 0.10 [mu]g
paraqut cation/L based on histopathological changes to the epithelium
of the larynx and nasal discharge.
5.Chronic toxicity. In a 12-month feeding study, dogs were fed dose
levels of 0, 15, 30, or 50 ppm, expressed as paraquat cation. These
levels corresponded to 0, 0.45, 0.93, or 1.51 mg of paraquat cation/kg/
day, respectively, in male dogs or 0, 0.48, 1.00, or 1.58 mg of
paraquat cation/kg/day, respectively for female dogs. There was a dose-
related increase in the severity and extent of chronic pneumonitis in
the mid-dose and high-dose male and female dogs. This effect was also
noted in the low-dose male group, but was minimal when compared with
the male controls. The systemic NOEL is 15 ppm (0.45 mg/kg/day for
males and 0.48 mg/kg/day for females, expressed as paraquat cation).
The systemic LOEL is 30 ppm (0.93 mg/kg/day for males and 1.00 mg/kg/
day for females, expressed as paraquat cation).
In a 2-year chronic feeding/carcinogenicity study, rats were fed
doses of paraquat dichloride at 0, 25, 75, or 150 ppm which corresponds
to 0, 1.25, 3.75, or 7.5 mg of paraquat cation/kg/day. Paraquat
dichloride enhanced the development of ocular lesions in all of the
treated groups. The predominant lesions detected opthamoscopically were
lenticular opacities and cataracts. At test week 103, dose-related
statistically significant (P< 0.001) increases in the incidence of
ocular lesions were observed only in the mid-dose and high-dose male
and female groups. Based on these findings, the NOEL (approximate) and
the LOEL for systemic toxicity, for both sexes, are 25 ppm (1.25 mg/kg/
day) and 75 ppm (3.75 mg/kg/day), respectively. In this study, there
was uncertain evidence of carcinogenicity (squamous cell carcinomas in
the head region; ears, nasal cavity, oral cavity, and skin) in males at
7.5 mg/kg/day (HDT) with a systemic NOEL of 1.25 mg/kg/day. Upon
submission of additional data to EPA, the incidence of pulmonary
adenomas and carcinomas was well within historical ranges and it was
determined that paraquat dichloride was not carcinogenic in the lungs
and head region of the rat.
In another 2-year chronic feeding/carcinogenicity study, rats were
dosed at 0, 6, 30, 100 or 300 ppm, expressed as paraquat dichloride
(nominal concentrations), equivalent to 0, 0.25, 1.26, 4.15, or 12.25
mg/kg/day, respectively (males) and 0, 0.30, 1.5, 5.12, or 15.29 mg/kg/
day respectively (females), expressed as paraquat dichloride. The
incidence of ocular changes was low and not caused by paraquat
dichloride in this study. The systemic NOEL is 100 ppm of paraquat
dichloride (4.15 and 5.12 mg/kg/day, for males and females,
respectively); or 3.0 mg/kg/day (males) and 3.7 mg/kg/day (females),
expressed as paraquat cation. The systemic LOEL is 300 ppm of paraquat
dichloride (12.25 and 15.29 mg/kg/day, for males and females,
respectively); or 9.0 mg/kg/day (males) and 11.2 mg/kg/day (females),
expressed as paraquat cation. There were no
[[Page 37402]]
evidence of carcinogenicity in this study even at the highest dose
tested.
In a two year chronic feeding/oncogenicity study, SPF Swiss derived
mice were fed paraquat dichloride at dose levels of 0, 12.5, 37.5, or
100/125 ppm, expressed as cation. Because no toxic signs appeared after
35 weeks of dosing, the 100 ppm level was increased to 125 ppm at week
36. There were no carcinogenic effects observed in this study. The
systemic NOEL for both sexes is 12.5 ppm (1.87 mg/kg/day) and the
systemic LOEL is 37.5 ppm (5.6 mg/kg/day), each expressed as paraquat
cation based on renal tubular degeneration in males and weight loss and
decreased food intake in females. Paraquat dichloride is classified
Category E of carcinogenicity (no evidence of carcinogenicity in animal
studies).
6. Animal metabolism. The qualitative nature of the residue in
animals is adequately understood based on the combined studies
conducted with ruminants (goats and cows), swine, and poultry. The
residue of concern in eggs, milk, and poultry and livestock tissue is
the parent, paraquat dichloride.
7. Metabolite toxicology. The nature of the residues in plants and
animals is adequately understood. The residue of concern in eggs, milk,
poultry, livestock, and in crops is the parent, paraquat dichloride.
8. Endocrine disruption. There is no evidence of endocrine effects
in the database supporting registration of paraquat dichloride.
C. Aggregate Exposure
1. Dietary exposure. Syngenta Crop Protection, Inc. has estimated
aggregate exposure based on all proposed and established tolerances.
2. Food. For the purposes of assessing the potential dietary
exposure under the proposed tolerances, Syngenta Crop Protection has
estimated aggregate exposure from all crops for which tolerances are
established or proposed (i.e., pesticide petition PP2F6433).
i. Acute exposure. The paraquat dichloride acute dietary exposure
assessment utilized the Dietary Exposure Evaluation Model
(DEEMTM, version 7.76) and the USDA's Continuing Survey of
Food Intake by Individuals (CSFII) with the 1994-96 consumption
database and the Supplemental CSFII Children's Survey (1998)
consumption database. The acute reference dose (aRfD) for paraquat
dichloride is 0.0042 mg/kg-bw/day for females 13-50 years of age and
0.0125 mg/kg-bw/day for children and the U.S. population. The aRfD is
based on a reproduction study in rats with a no observable adverse
effect level (NOAEL) of 1.25 mg/kg-bw/day and an uncertainty factor of
100X. An additional FQPA safety factor of 3X was applied for females
between the ages of 13 and 50 years due to a data gap for a prenatal
developmental study conducted in a non-rodent species. The paraquat
dichloride Tier II acute dietary exposure assessment was based upon
established and proposed tolerances for paraquat dichloride. The
maximum percent crop treated (%CT) values that were described in the
most recent EPA exposure assessment for paraquat dichloride (published
in the Federal Register) of September 21, 2001 (66 FR 48593)(FRL-6799-
2) were used for all currently registered crops. One-hundred percent
crop treated was assumed for all proposed crops. It should be noted
that the most recent EPA acute exposure assessment for paraquat
dichloride was based on a probabilistic Monte Carlo analysis using
tolerance residue values. The current Syngenta acute assessment was
performed deterministically using tolerance residue values. For the
purpose of aggregate risk assessment, the exposure values were
expressed in terms of margin of exposure (MOE) which was calculated by
dividing the no observable adverse effect level (NOAEL) by the exposure
for each population subgroup. In addition, exposure was expressed as a
percent of the acute reference dose (%aRfD). Acute exposure to the U.S.
population resulted in a MOE of 377 (26.47% of the aRfD of 0.0125 mg/
kg-bw/day). The most exposed sub-population was females (13-19 years,
not pregnant or nursing) with a MOE of 712 (41.78% of the aRfD of
0.0042 mg/kg-bw/day). Since the benchmark MOE for females (13-50 years
of age) was 300 and since EPA generally has no concern for exposures
below 100% of the RfD, Syngenta believes that there is a reasonable
certainty that no harm will result from dietary (food) exposure to
residues arising from the current and proposed uses of paraquat
dichloride.
ii. Chronic exposure. The paraquat dichloride chronic dietary
exposure assessment utilized the Dietary Exposure Evaluation Model
(DEEMTM, version 7.76) and the USDA's Continuing Survey of
Food Intake by Individuals (CSFII) with the 1994-96 consumption
database and the Supplemental CSFII Children's Survey (1998)
consumption database. The chronic reference dose (cRfD) for paraquat
dichloride is 0.0045 mg/kg-bw/day and is based on a one-year feeding
study in dogs with a NOAEL of 0.45 mg/kg-bw/day and an uncertainly
factor of 100X. No additional FQPA safety factor was applied. The
paraquat dichloride Tier II chronic dietary exposure assessment was
based upon established and proposed tolerances for paraquat dichloride.
The average percent crop treated (%CT) values that were described in
the most recent EPA exposure assessment for paraquat dichloride
published in the Federal Register of September 21, 2001, were used for
all currently registered crops. For the proposed crops, it was assumed
that 100 percent of these crops were treated. For the purpose of
aggregate risk assessment, the exposure values were expressed in terms
of MOE and as a percent of the reference dose (%RfD). Chronic exposure
to the U.S. population resulted in a MOE of 1,475 (6.8% of the cRfD of
0.0045 mg/kg-bw/day). The most exposed sub-population was children (1-6
years old) with a MOE of 507 (19.7% of the cRfD). Since the benchmark
MOE for this assessment was 100 and since EPA generally has no concern
for exposures below 100% of the RfD, Syngenta believes that there is a
reasonable certainty that no harm will result from dietary (food)
exposure to residues arising from the current and proposed uses of
paraquat dichloride.
1. Drinking water. To estimate total aggregate exposure to a
pesticide from food, drinking water and residential uses, the Agency
calculates the drinking water level of comparison (DWLOCs) which are
used as a point of comparison against the model estimates of a
pesticide's concentration in water (EECs). When EECs for surface water
and ground water are less than the calculated DWLOCs, EPA concludes
with reasonable certainty that exposures to the pesticide in drinking
water would not result in unacceptable levels of aggregate human health
risk. The calculated DWLOC for acute exposure to paraquat dichloride in
surface and ground water was 74 ppb for the most exposed sub-population
(females 13-19 years, not pregnant or nursing). The calculated DWLOC
for chronic exposure to paraquat dichloride in surface and ground water
was 36 ppb for the most exposed sub-population (children 1-6 years).
Based on the comparison to the EECs for surface and ground water, the
estimated environmental concentrations of paraquat dichloride in
surface and ground water are below the DWLOC based upon food exposures;
therefore, the EPA should not have a drinking water concern for
paraquat dichloride.
2. Non-dietary exposure. Paraquat dichloride is not registered for
use on any sites that would result in residential exposure.
[[Page 37403]]
D. Cumulative Effects
Cumulative exposure to substances with a common mechanism of
toxicity. Section 408(b)(2)(D)(v) requires that, when considering
whether to establish, modify, or revoke a tolerance, the Agency
consider ``available information'' concerning the cumulative effects of
a particular pesticide's residues and ``other substances that have a
common mechanism of toxicity.'' The EPA does not have, at this time,
available data to determine whether paraquat dichloride has a common
mechanism of toxicity with other substances or how to include this
pesticide in a cumulative risk assessment. For the purposes of this
tolerance action, the EPA has not assumed that paraquat dichloride has
a common mechanism of toxicity with other substances.
E. Safety Determination
1. U.S. population--i. Acute risk. The acute dietary exposure
analysis (food only) showed that exposure from all established and
proposed paraquat dichloride tolerances would be 26.5% of the aRfD for
the general U.S. population.
ii. Chronic risk. The chronic dietary exposure analysis (food only)
showed that exposure from all established and proposed paraquat
dichloride tolerances would be 6.8% of the cRfD for the general U.S.
population.
2. Females 13-50 years of age-- Acute risk. The acute dietary
exposure analysis (food only) showed that exposure from all established
and proposed paraquat dichloride tolerances would be 41.8% of the aRfD
for the most exposed sub-population (females 13-19, not pregnant or
nursing).
3. Infants and children--i. Acute risk. The acute dietary exposure
analysis (food only) showed that exposure from all established and
proposed paraquat dichloride tolerances would be 38.3% of the aRfD for
the next most exposed sub-population (children 1-6 years).
ii. Chronic risk. The chronic dietary exposure analysis (food only)
showed that exposure from established and proposed paraquat dichloride
tolerances would be 19.7% of the cRfD for the most exposed sub-
population (children 1-6 years). The next most exposed sub-population
was non-nursing infants with an exposure of 12.7% of the cRfD. There is
no indication of quantitative or qualitative increased susceptibility
of rats or mice to in utero and/or prenatal/postnatal exposure to
paraquat dichloride. The EPA has determined that a developmental
neurotoxicity study is not required. Infants and children are not
expected to show any particular sensitivity to paraquat dichloride.
Syngenta has considered the potential aggregate exposure from food
and water and concluded that aggregate exposure is not expected to
exceed 100% of the acute or chronic reference dose and that there is a
reasonable certainty that no harm will result to infants and children
from the aggregate exposure to paraquat dichloride.
F. International Tolerances
Compatibility between U.S. tolerances and Codex Maximum Residue
Levels (MRLs) exist for eggs, milk, ruminant tissues, passion fruit,
sunflower seed and vegetables including beans (succulent), brassica
(cole) leafy vegetables group, carrots, cassava, corn (sweet),
cucurbits, fruiting vegetables, lettuce, onions (dry bulb and green),
peas (succulent), pigeon peas, turnips (roots and tops), and yams.
Incompatibilities of U.S. tolerances and Codex MRLs on the following
raw plant commodities remain because of differences in agricultural
practices: Cottonseed, dry hops, dry peas/beans, maize, olives,
potatoes, rice, sorghum, soybeans and wheat. No questions of
compatibility exists with respect to commodities where no Codex MRLs
have been established but United States tolerances exist or where Codex
MRLs have been established but U.S. tolerances do not exist.
[FR Doc. 05-12445 Filed 6-28-05; 8:45 am]
BILLING CODE 6560-50-S