[Federal Register Volume 69, Number 88 (Thursday, May 6, 2004)]
[Notices]
[Pages 25384-25390]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-10288]


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ENVIRONMENTAL PROTECTION AGENCY

[OPP-2004-0122; FRL-7356-8]


DCPA; 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 ID number OPP-2004-0122, must be 
received on or before June 7, 2004.

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: Joanne I. Miller, Registration 
Division (7505C), Office of Pesticide Programs, Environmental 
Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460-
0001; telephone number: (703) 305-6224; e-mail address: 
[email protected].

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this Action Apply to Me?

     You may be potentially affected by this action if you are an 
agricultural producer, food manufacturer, or pesticide manufacturer. 
Potentially affected entities may include, but are not limited to.
     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. EPA Docket. EPA has established an official public docket for 
this action under docket ID number OPP-2004-0122. 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, 1921 Jefferson Davis Hwy., 
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 towards 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 on 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

[[Page 25385]]

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-2004-0122. 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 [email protected], 
Attention: Docket ID number OPP-2004-0122. 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 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-2004-0122.
    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, 1921 Jefferson Davis Hwy., Arlington, VA, Attention: Docket 
ID number OPP-2004-0122. 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 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.

[[Page 25386]]

List of Subjects

     Environmental protection, Agricultural commodities, Feed 
additives, Food additives, Pesticides and pests, Reporting and 
recordkeeping requirements.

    Dated: April 26, 2004.
 Betty Shackleford,
Acting Director, Registration Division, Office of Pesticide Programs.

Summary of Petition

     The petitioner's summary of the pesticide petition is printed 
below as required by FFDCA section 408(d)(3). The summary of the 
petition was prepared by Interregional Research Project Number 4 (IR-
4), 681 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.

 Interregional Research Project Number 4 (IR-4)

 PP 2E6442

     EPA has received a pesticide petition 2E6442 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 
the FFDCA, 21 U.S.C. 346a(d), to amend 40 CFR part 180 by establishing 
a tolerance for residues of DCPA, or chlorthal dimethyl (dimethyl 
tetrachloroterephthalate) in or on the raw agricultural commodities 
Oriental radish, basil, coriander, dill, marjoram, chives, ginseng, 
celeriac, chicory, mradicchio, parsley (fresh) and parsley (dried) at 
2.0, 5.0, 5.0, 5.0, 5.0, 5.0, 2.0, 2.0, 5.0, 2.0, 5.0 and 15 parts per 
million (ppm), respectively. 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 qualitative nature of the residue in 
plants is adequately understood based on acceptable studies on onions, 
turnips, and tobacco. The residues of concern in plants are DCPA, and 
its metabolites monomethyl tetrachloroterephthalic acid (MTP) and 
tetrachloroterephthalic acid (TPA) which are the parent and metabolites 
that are currently regulated. The proposed metabolism of DCPA in plants 
is via ester hydrolysis. Studies conducted with onion and turnip 
indicate that the impurity hexachlorobenzene (HCB) is not metabolized 
appreciably in these plants.
    2. Analytical method. Three tolerance enforcement methods for plant 
commodities are published in the Pesticide Analytical Manual (PAM), 
Vol. II (Section 180.185), as Methods A, B, and C. Residue data 
submitted in response to the 6/88 Guidance Document were collected 
using gas chromatography/electron capture (GC/EC) methods similar to 
the PAM, Vol. II methods. The Agency has found these methods to be 
adequate for collection of DCPA, HCB, MTP, and TPA residue data from 
potatoes (including processed commodities), sweet potatoes, broccoli, 
celery, cucumbers, green and bulb onions, strawberries, sweet and bell 
peppers, cantaloupes, tomatoes (including processed commodities), 
summer squash, and processed commodities of beans and cottonseed. The 
limits of detection (LOD) are 0.01 ppm each for DCPA, MTP, and TPA, and 
0.0005 ppm for HCB. These methods are suitable candidates for 
validation procedures as enforcement methods for plant commodities. 
Another GC/EC method, similar to those submitted for plants, is 
available for determining DCPA, MTP, and TPA in milk and beef fat. 
Recoveries of each compound using 12 samples each of milk and beef fat 
fortified at 0.01-5 ppm were acceptable. The LOD is 0.01 ppm. The 
Agency has deemed this method is suitable for its validation and 
inclusion in PAM, Vol. II pending successful independent laboratory 
validation. DCPA per se is completely recovered using PAM, Vol. I 
Multiresidue Protocols D and E (PESTDATA, PAM, Vol. I, Appendix, 8/93). 
Data submitted by the previous registrant indicate that TPA is not 
recovered by Protocols B and C. The Agency has indicated that 
multiresidue testing data on MTP are still required.
    3. Magnitude of residues--i. Oriental radish. IR-4 has received a 
request from California for the use of DCPA on oriental radish. IR-4 
supports the requested tolerance of 2 ppm on oriental radish based on 
other existing tolerances.
    ii. Basil. IR-4 has received a request from California for the use 
of DCPA on basil. IR-4 supports the requested tolerance of 5 ppm on 
basil based on other existing tolerances.
    iii. Coriander. IR-4 has received a request from California for the 
use of DCPA on coriander. IR-4 supports the requested tolerance of 5 
ppm on coriander based on other existing tolerances.
    iv. Dill. IR-4 has received a request from California for the use 
of DCPA on fresh dill. IR-4 supports the requested tolerance of 5 ppm 
on fresh dill based on other existing tolerances.
    v. Marjoram. IR-4 has received a request from California for the 
use of DCPA on marjoram. IR-4 supports the requested tolerance of 5 ppm 
on marjoram based on other existing tolerances.
    vi. Chives. IR-4 has received a request from California for the use 
of DCPA on chives. IR-4 supports the requested tolerance of 5 ppm on 
chives based on other existing tolerances.
    vii. Ginseng. IR-4 has received requests from Wisconsin and North 
Carolina for the use of DCPA on ginseng. IR-4 supports the requested 
tolerance of 2 ppm on ginseng based on other existing tolerances.
    viii. Celeriac. IR-4 has received a request from California for the 
use of DCPA on celeriac. IR-4 supports the requested tolerance of 2 ppm 
on celeriac based on other existing tolerances. Chicory: IR-4 has 
received a request from California for the use of DCPA on chicory. IR-4 
supports the requested tolerance of 5 ppm on chicory based on other 
existing tolerances.
    ix. Radicchio. IR-4 has received a request from California for the 
use of DCPA on radicchio. IR-4 supports the requested tolerance of 2 
ppm on radicchio based on other existing tolerances.

B. Toxicological Profile

     DCPA technical is classified under Toxicity Category IV 
(practically non-toxic) for acute-oral toxicity and dermal irritation 
and Toxicity Category III (slightly toxic) for dermal lethal dose 
(LD)50, inhalation lethal concentration (LC)50, 
and eye irritation. DCPA is not a dermal sensitizer. DCPA has been 
classified as a Group C, possible human carcinogen, based on increased 
incidence of thyroid tumors in both sexes of the rat (although, only at 
an excessive dose in the female), and liver tumors in female rats and 
mice, at doses which were not excessive.
    1. Acute toxicity. The acute oral LD50 values for DCPA 
in the rat was >5,000 milligrams/kilogram (mg/kg). The acute dermal 
LD50 was >2,000 mg/kg in the rabbit. The 4-hour rat 
inhalation LC50 was >4.48 milligrams/per Liter (mg/L). DCPA 
was a mild irritant to rabbit skin and eyes. DCPA (performed with a 90% 
material) did not cause skin sensitization in guinea pigs.
    2. Genotoxicity. Mutagenicity studies as shown below have 
demonstrated that

[[Page 25387]]

DCPA is non-mutagenic both in vivo and in vitro. DCPA did not induce a 
mutagenic response in two independently performed mouse lymphoma 
forward mutation assays. The nonactivated concentration range was 7.5 
to 100 milligrams/milliliter (mg/mL) and the S9-activated range was 15 
to 200 mg/mL (MRID 41054822). In an in vitro cytogenetic assay, Chinese 
hamster ovary cells were exposed to DCPA at dose levels of 0, 30, 100, 
300, or 1,000 mg/mL for 4 hours both with and without S-9 activation. 
Cells were harvested at 12 and 18 hours. There were no indications of a 
clastogenic response as a result of exposure to test material at any 
dose level (MRID 41054823). DCPA was not genotoxic in two independently 
performed unscheduled DNA synthesis (UDS) assays in which the 
concentration ranged from 3 to 1,000 mg/mL (MRID 41054824). An in vitro 
assay for sister chromatid exchange (SCE) in Chinese hamster ovary 
cells was performed at dose levels of 0, 38, 75, 150, or 300 mg/mL both 
with and without S9-activation. There was no indication of a positive 
response; therefore, under the conditions of this assay the test 
material is negative (MRID 41054825).
    3. Reproductive and developmental toxicity. A developmental 
toxicity study with Sprague Dawley rats used doses of 0, 500, 1,000, or 
2,000 mg/kg/day given by gavage on gestation days 6-15. No adverse 
effects on the maternal rats or their offspring were observed. 
Therefore, the maternal and developmental toxicity no observed effect 
levels (NOELs) were set at 2,000 mg/kg/day, highest dose tested (MRID 
00160685).
     Two studies were conducted with New Zealand white rabbits. In the 
first study, DCPA doses of 0, 500, 1,000, or 1,500 mg/kg/day were given 
by gavage on gestation days 6-19. There were maternal deaths and 
adverse clinical signs at all dose levels. In the second study, DCPA 
doses of 0, 125, 250, or 500 mg/kg/day were given by gavage on 
gestation days 7-19. None of these levels produced any maternal or 
developmental toxicity. The second study tested dose levels that 
overlapped those in the first study. Therefore, when considered 
together, the no observed adverse effect level (NOAEL) for maternal 
toxicity can be set at 250 mg/kg and the lowest observed adverse effect 
level (LOAEL) can be set at 500 mg/kg based on maternal deaths. The 
developmental toxicity NOAEL can be set at 500 mg/kg. Although, no 
developmental effects were observed at any of the higher dose levels, a 
higher NOAEL cannot be set based on the limited number of litters at 
the higher dose levels.
     In a 2-generation reproduction study, female Sprague Dawley rats 
were fed DCPA at doses of 0, 63, 319, or 1,273 mg/kg/day while males 
received doses of 45, 233, or 952 mg/kg/day DCPA. These doses were 
equivalent to 0, 1,000, 5,000, and 20,000 ppm food residue values, 
which the Agency used in mammalian environmental risk. No effects on 
reproductive performance in 2 generations with 2 litters per generation 
were seen. The maternal NOAEL was 63 mg/kg/day. The maternal LOAEL was 
319 mg/kg/day, based on decreased body weight/body weight gain. The 
reproductive NOAEL was 63 mg/kg/day. The LOAEL was 319 mg/kg/day, based 
on decreased pup body weight. The paternal NOAEL was set at 233 mg/kg/
day, and the LOAEL was set at 952 mg/kg/day due to decreased body 
weight gain. On day 0 of the F2b litters, the diets for the low and 
mid-dose groups were changed to 18 and 47 mg/kg/day respectively to be 
able to set a NOAEL for pup body weight. The offspring NOAEL was set at 
18 mg/kg/day (200 ppm), and the LOAEL was 47 mg/kg/day (500 ppm) based 
on decreased body weight. (MRIDs 41750103, 41905201).
    4. Subchronic toxicity. In a 21-day dermal toxicity study, Charles 
River CD rats were dermally exposed to DCPA doses of 0, 100, 300, or 
1,000 mg/kg/day. No dermal irritation at the site of application was 
observed. No adverse effects were found; therefore, the NOEL was equal 
to or greater than 1,000 mg/kg/day, the highest dose tested (MRID 
41231803).
     CD VAF/Plus Sprague Dawley rats were given 0, 10, 50, 100, 150, or 
1,000 mg/kg/day of DCPA in the diet for 90 days. The NOAEL was 10 mg/
kg/day. The LOAEL was 50 mg/kg/day, based on increased liver weight and 
microscopic effects. The treatment-related effects were: Increased 
weight and centrilobular hypertrophy in the liver; increased 
accumulation of foamy macrophages in the lung; increased weight, 
epithelial hyperplasia, and tubular hypertrophy of the kidney; and 
follicular hypertrophy of the thyroid. There were slight decreases in 
body weight and food consumption in high dose females only (MRID 
41767901).
     Male CD-1 mice were given doses of 0, 100, 199, 406, or 1,235 mg/
kg/day DCPA and females were given 0, 223, 517, 1049, or 2,198 mg/kg/
day DCPA in the diet for 90 days. There were no effects other than 
minimal histopathological effects on the liver. The NOAEL was 406 mg/
kg/day for males and 517 mg/kg/day for females. The LOAEL for males was 
1235 mg/kg/day and for females was 1,049 mg/kg/day, based on the liver 
effects (MRID 41064801).
    5. Chronic toxicity. Beagle dogs were given 0, 2.5, 25, or 250 mg/
kg/day DCPA in the feed for 2 years. Adverse effects were not found. 
Therefore, the NOAEL was equal to or greater than 250 mg/kg/day (MRID 
00083584).
     A chronic toxicity and carcinogenicity study was conducted with 
Sprague Dawley CD rats. The doses of DCPA given in the diet for 2 years 
were 0, 1, 10, 50, 500 or 1,000 mg/kg/day. The NOAEL was 1 mg/kg/day. 
The LOAEL was 10 mg/kg/day, with effects observed in the lungs, liver, 
and thyroid; decreases in thyroid hormone levels in both sexes; and 
effects in eyes in females. The specific effects were: (1) Increased 
mortality in males at 1,000 mg/kg/day HDT during the second year; (2) 
either decreased body weights or decreased body weight gains in both 
sexes at 1,000 mg/kg/day, and in females at 500 mg/kg/day; (3) changes 
in hematology and clinical chemistry parameters indicative of liver and 
kidney toxicity at both 500 and 1,000 mg/kg/day in both sexes; (4) 
treatment-related increases in thyroid, liver, and kidney weights in 
both sexes; (5) a dose-related increase in white foci in the lungs, 
which correlated with an increased incidence of foaming macrophages in 
both sexes at doses of 10 mg/kg/day and higher; (6) treatment-related 
exacerbation of chronic nephropathy in both sexes at 50 mg/kg/day and 
higher; (7) a dose-related increase in centrilobular hepatocytic 
swelling in both sexes at doses of 10 mg/kg/day and higher; (8) a dose-
related increase in liver neoplasms in females; (9) an increase in 
follicular cell hyperplasia/hypertrophy at 10 mg/kg/day in males and at 
doses of 50 mg/kg/day and higher in both sexes; (10) decreased T4 
(thyroid hormone/thyroxine) values at 10 mg/kg/day in males, and at 50 
mg/kg/day and higher in both sexes; and (11) a treatment-related 
increase in thyroid follicular cell neoplasms in both sexes (MRID 
42731001).
     In another combined chronic toxicity and carcinogenicity study, 
CD-1 mice were given DCPA in the diet for 2 years. The doses were 0, 
12, 123, 435, or 930 mg/kg/day DCPA in the diet for males and 0, 15, 
150, 510, or 1,141 mg/kg/day for females. The NOAEL for systemic 
effects was 435 mg/kg/day in males; 510 mg/kg/day in females. The 
systemic lowest observed effect level (LOEL) was 930 mg/kg/day in 
males; 1,141 mg/kg/day in females, based on liver effects. There were 
increased liver weights,

[[Page 25388]]

increased SDH (sorbital dehydrogenase) and GPT (glutamic-pyruvic 
transaminase) activities, and increased incidence of hepatocyte 
enlargement or vacuolation in both sexes at the high dose levels; 930 
and 1,141 mg/kg/day for males and females, respectively. There was a 
significant increase in hepatocellular neoplasms in females at the high 
dose level of 1,141 mg/kg/day. Corneal opacity was observed in this 
study (MRID 40958701).
     Additionally, a supplementary rat chronic ophthalmology study was 
conducted to investigate the corneal opacity observed in the mouse 
study. There was no evidence of ocular toxicity observed in rats fed 
DCPA in the diet at levels up to 1,000 mg/kg/day for 2 years (MRID 
41750102).
    6. Animal metabolism. In one study, a single oral dose of 
14C -DCPA at either 1 or 1,000 mg/kg was given to Sprague-
Dawley rats (5 rats/sex/dose level). The major metabolite of DCPA in 
the urine of both sexes at both dose levels was 4-carbomethoxy-2,3,5,6-
tetrachlorobenzoic acid. No radiolabel was excreted in the urine as the 
parent compound, DCPA (MRID 42155501).
     There was a second study in which a single oral dose of 
14C -DCPA at either 1 or 1,000 mg/kg was given to Sprague-
Dawley rats. Bile was found to be a negligible excretory route for 
radiolabeled DCPA. At the low dose, 61% of the administered 
radiolabeled DCPA was excreted in the urine. The percent absorption 
(urine, blood, bile, cage rinse, and carcass) was 79% of the 
administered dose. At the high dose, 55% of the administered radiolabel 
was excreted in the feces or was found in the GIT (gastro-intestinal 
tract). The percent absorption was 8% of the administered dose (MRID 
42155503).
     There was a third study in which a single oral dose of 
14C -DCPA at either 1 or 1,000 mg/kg was given to Sprague-
Dawley rats (3 rats/sex/dose level) to determine the major route of 
excretion. Urine was the major route at the low dose, and feces was the 
major route at the high dose. Negligible amounts of radiolabel were 
found in the tissues examined at 48 hours following dosing. There were 
no significant differences observed between the sexes at either dose 
level (MRID 42155502).
     In a different study, nonradiolabeled DCPA was administered in 
single, daily oral doses to Crl:CD BR VAF/Plus rats (15 rats/sex/dose 
level) for 14 consecutive days at either the 1 or 1,000 mg/kg/day dose 
level. Twenty-four hours after the 14th dose, a single oral 
dose of 14C-DCPA (1 or 1,000 mg/kg) was administered to each 
rat. At the high dose level (both sexes), the majority of the 
administered 14C-DCPA was unabsorbed and was eliminated in 
the feces, while at the low dose level (both sexes) the majority of the 
administered 14C-DCPA was absorbed and excreted in the 
urine. Radiolabel was found in all tissues examined, and the radiolabel 
concentration was higher in the high-dose rat tissue than in the same 
tissue at the low dose level. At 168 hours, radiolabel was still 
detectable in nearly all tissues at both dose levels and in both sexes. 
The elimination half-life of radiolabel was calculated to be 22-23 
hours at the high dose and approximately 18-hours at the low dose. 
(MRID 42723201, 42723202).
     In another study, Sprague-Dawley rats (5 rats/sex/dose level) were 
given single or multiple 14-days oral doses of 14C-DCPA (1 
or 1,000 mg/kg). The major metabolite of DCPA in the urine of both 
sexes at both dose levels following both single and multiple dosing was 
4-carbomethoxy-2,3,5,6-tetrachlorobenzoic acid. A minor metabolite was 
tetrachloroterephthalic acid. No radiolabel was excreted in the urine 
as the parent compound, DCPA (MRID 42723203). Together these studies 
fulfill GLN 870.7485 (old GLN 85-1) (MRID 43052201).
    7. Metabolite toxicology--i. Hexachlorobeneze (HCB) as a DCPA 
impurity. HCB is a recognized impurity in DCPA. The Agency has 
classified HCB as a B2 (probable human) carcinogen, based on data sets 
which showed significant increases of tumor incidence in 2 species: 
Hamsters and rats. In a 130-week feeding study in rats, the NOAEL was 
0.08 mg/kg/day. (Effects observed were hepatic centrilobular basophilic 
chromogenesis.) The dermal absorption factor of HCB is 26.46% (MRID 
42651501). At this time no other toxicological endpoints of concern 
have been identified for HCB.
     The Agency risk assessment of HCB was based on levels in the 
original DCPA source material. Since then, the Agency has acknowledged 
in RED correspondence that the new registrant committed to reducing HCB 
concentrations in its source material. Subsequently, the Agency in fact 
confirmed a new technical registration (granted to AMVAC Chemical 
Corporation) with HCB concentrations almost two orders lower in 
magnitude than before. As a result, the potential HCB exposures to 
humans is concomitantly reduced to a fraction of the potential exposure 
considered by EPA in its original RED risk assessment.
    ii. Polyhalogenated dibenzo-p-dioxins/dibenzofurans as DCPA 
Impurities. Polyhalogenated dibenzo-p-dioxins/dibenzofurans (dioxin/
furans) are recognized impurities of DCPA. Of the dioxin/furans, only 
the 2,3,7,8-tetrachloro-dibenzo-para-dioxin (2,3,7,8-TCDD) congener has 
been assigned a quantified estimate of its carcinogenic potential. The 
Agency has classified 2,3,7,8-TCDD as a B2 (probable human) carcinogen 
based on data sets which showed significant increases of tumor 
incidence in 2 species: Sprague-Dawley rats and B6C3F1 mice.
     Enough data exist, however, regarding the potency of the other 
congeners to estimate their relative potency in comparison to the 
2,3,7,8-TCDD. Therefore, in evaluating the toxicological significance 
of the dioxin/furan contamination, the Agency converts all of the 
congener detection values into one value which represents the 
equivalent 2,3,7,8-TCDD potency. For example, if a product contained 10 
parts per billion (ppb) of a dioxin congener other than the 2,3,7,8-
TCDD, and if that congener is considered to be only 1/10th 
as potent as 2,3,7,8-TCDD, the Agency would use the equivalent of 1 ppb 
of 2,3,7,8-TCDD in its risk assessment. DCPA's prior registrant 
submitted dioxin/furan detection values to the Agency from seven batch 
samples, as required in the 1987 DCI. During the first sampling, one of 
the dioxin/furan congeners was detected above the Agency specified 
level of quantitation (LOQ). The manufacturing process was subsequently 
altered in an effort to reduce this contamination. (MRID 41241801). 
Subsequent to this change, none of the dioxin/furan congeners were 
detected above Agency specified LOQs in the remaining six batch 
samples. The 2,3,7,8-TCDD equivalency of the dioxin/furans reported to 
the Agency is approximately 0.1 ppb, which would equal 0.00000001% of 
the DCPA formulations. The Agency used this contamination value 
(0.00000001%) to determine exposure values used in the risk assessments 
for DCPA's reregistration eligibility evaluation. The Agency required 
registrants to propose certified upper limits for all dioxin/furan 
congeners for which detection values were reported to the Agency.
     The reference dose (RfD) for 2,3,7,8-TCDD is 0.000001 [mu]g/kg/
day) based on a LOAEL of 0.001 [mu]g/kg/day from a three-generation 
feeding study in rats. (Effects at the lowest dose tested included 
dilated renal pelvises, decreased fetal weight, and changes in the 
gestational index). An uncertainty factor of 100 was used to account 
for the interspecies extrapolation and intraspecies variability. An 
additional uncertainty factor of 10 was used to

[[Page 25389]]

account for the lack of a NOAEL. At this time, no other toxicological 
endpoints of concern have been identified for 2,3,7,8-TCDD.
    iii. Tetrachloroterephthalic acid (TPA) as a DCPA metabolite. 
tetrachloro-terephthalic acid (TPA) is one of two DCPA animal 
metabolites. DCPA fed to lactating goats was metabolized into both TPA 
and monomethyl tetrachloroterephthalic acid (MTP). It is the TPA 
metabolite, however, that is found most frequently in the environment 
after DCPA use. Soil metabolism converts DCPA into TPA, which is known 
to leach through soil and pollute ground water. Therefore, the prior 
registrant submitted the following additional studies to specifically 
assess the toxicity of TPA.
    8. Subchronic toxicity of TPA. Disodium 2,3,5,6-
tetrachloroterephthalic acid was given to Charles River CD rats in the 
diet for 13-weeks. There were 15 rats/sex/dose group using dose levels 
of 0, 2.5, 25, 50, or 500 mg/kg/day. There were no adverse effects in 
either sex at any dose level. The NOAEL is greater than or equal to 500 
mg/kg/day, the highest dose tested. The LOAEL cannot be determined 
(MRID 00100773).
     CD Sprague-Dawley rats (10/sex/dose group) were given 2,3,5,6-
tetrachloroterephthalic acid via gavage for 30 days at dose levels of 
0, 100, 500, or 2,000 mg/kg/day. There were no apparent adverse effects 
observed at any dose level. The NOAEL is greater than or equal to 2,000 
mg/kg/day, the highest dose tested. The LOAEL cannot be determined. 
(MRID 00158011).
    9. Developmental toxicity of TPA. In a developmental toxicity 
study, 25 pregnant Charles River rats/dose group were dosed via gavage 
on gestation days 6-15 with TPA at dose levels of 0, 625, 1,250, or 
2,500 mg/kg/day. The maternal toxicity NOEL was 1,250 mg/kg/day. The 
maternal LOAEL was set at 2,500 mg/kg/day based on decreased body-
weight gain and food consumption. There were no signs of developmental 
toxicity, therefore, the developmental NOAEL was set at 2,500 mg/kg/
day, the highest dose tested. A LOAEL was not determined (MRID 262303).
    10. Mutagenicity of TPA. TPA did not induce a mutagenic response in 
the Ames assay or the HGPRT assay with or without metabolic activation 
(MRID 262302). In the Sister Chromatid Exchange (SCE) assay, TPA did 
not induce a significant increase in the SCE frequency of Chinese 
hamster ovary cells, both with and without metabolic activation. TPA 
did not induce an increase in unscheduled DNA synthesis. In an in vivo 
mouse micronucleus assay, TPA was negative for clastogenicity in 
females and at best equivocal in males. Based on the overall weight of 
evidence of no mutagenic response of this compound in other studies, as 
well as the lack of mutagenicity of the parent DCPA, further testing 
for mutagenicity is not warranted at this time.
    11. Endocrine disruption. The toxicology data base for DCPA is 
current and complete. Studies in this data base include evaluation of 
the potential effects on reproduction and development, and an 
evaluation of the pathology of the endocrine organs following short-
term or long-term exposure. These studies revealed no primary endocrine 
effects due to DCPA.

C. Aggregate Exposure

    1. Dietary exposure--i. Food. Tolerances for residues of DCPA in or 
on raw agricultural commodities are currently expressed as the combined 
residues of DCPA and its metabolites monomethyl 
tetrachloroterephthalate (MTP) and tetrachloroterephthalic acid (TPA) 
calculated as DCPA. At present, no tolerances exist for residues of 
DCPA in animal commodities. Although, all the data requirements of the 
Reregistration Guidance had not been met when the Agency issued the 
RED, the outstanding data were considered to be confirmatory to the 
reregistration eligibility decision. The Agency determined that 
sufficient data are available to conduct reasonable anticipated residue 
assessments.
     People may be exposed to residues of DCPA through the diet. 
Tolerances or maximum residue limits have been established for residues 
of DCPA in many food and feed crops (see 40 CFR 180.185). EPA has 
reassessed the DCPA tolerances and found that some are acceptable, 
others must be revoked because refinements in crop groups must be 
replaced with new tolerances for the new crop groupings. Acute dietary 
risk assessments were not necessary since there were no acute 
toxicological endpoints of concern for DCPA or its impurities. Chronic 
and carcinogenic dietary risks were assessed, however, due to exposure 
to DCPA, HCB, and dioxin/furans.
     Chronic risk estimates for the U.S. population and all subgroups 
were well below 100% of the RfD for DCPA, HCB, and dioxin/furans. Based 
on these estimates, the Agency concluded that DCPA use does not pose a 
significant chronic dietary risk. Carcinogenic risk estimate for 
exposure to DCPA, HCB, and dioxin/furans through food were 3.5 x 
10-7, and 7 x 10-8, respectively. All of these 
risk estimates are within the range (zero to 1 x 10-6) 
generally considered to be negligible by the Agency. Thus, the Agency 
concluded that DCPA use does not pose a significant excess lifetime 
cancer risk.
    ii. Drinking water. The Agency assessed both chronic (non-cancer) 
and carcinogenic risk due to exposure to DCPA and its metabolites 
through contaminated ground water and surface water. The Agency used 
annual contamination averages from five geographic regions as potential 
drinking water exposure values. The highest annual average was 50 ppb 
in New York from a turf study. Although, this represents approximately 
71% of the health advisories (HA), it only corresponds to 11% of RfD. 
Even if part of this population were to the maximum 3% of the RfD from 
other dietary sources, the chronic dietary risk would still be 
considered minimal.
     Individual excess lifetime cancer risk from the New York turf site 
was 1.7 x 10-6. The next highest risk estimate is based on 
data from Suffolk County, New York. The risk estimate from that site is 
9.7 x 10-7. DCPA's previous registrant voluntarily withdrew 
from selling the product in Suffolk, New York. Exposure values from all 
other sites resulted in risks below the Agency's cancer benchmark of 1 
x 10-6. Based on these estimates, the Agency concluded that 
DCPA and its metabolites do not currently pose a significant cancer or 
chronic non-cancer risk from non-turf uses to the overall U.S. 
population from exposure through contaminated drinking water.
    2. Non-dietary exposure. DCPA is currently registered for 
commercial and residential use. Risk assessments were performed to 
assess the individual excess lifetime cancer risk from DCPA and HCB 
resulting from occupational and residential exposure to DCPA. The 
Agency will not generally allow non-dietary risks to exceed 
10-4, except in cases where EPA has determined that benefits 
exceed the risks.
    i. Occupational exposure. Risk was estimated for occupational 
exposures to both DCPA and HCB. The highest risk for both commercial 
applicators and private applicators is associated with the use of the 
wettable powder formulation. For the commercial applicator, the highest 
risk for DCPA was estimated to be 7.5 x 10-5 and for HCB (in 
DCPA) to be 1.9 x 10-4. The Agency is requiring mixer/
loader/applicators using DCPA wettable powders to wear a dust-mist 
respirator fitted with a TC-21 filter to mitigate this risk. Wearing a 
dust-mist respirator reduces the risks to 4.0 x 10-5 and 1.3 
x 10-4 for DCPA and HCB respectively.

[[Page 25390]]

     For the private applicator, the highest risk for DCPA was 
estimated to be 1.6 x 10-6 and for HCB (in DCPA) to be 4.6 x 
10-6.
    ii. Turfgrass. Risks to children playing on a treated lawn were 
assessed for exposure to DCPA and HCB. The risks from DCPA and HCB to 
children playing on an irrigated lawn are 5.6 x 10-7 and 3.9 
x 10-7, respectively. The risks from DCPA and HCB to 
children playing on non-irrigated lawns are 2.0 x 10-6 and 
2.7 x 10-6, respectively. The Agency is conducting a risk/
benefit assessment to determine whether the turf use is eligible for 
reregistration. However, in the interim, the Agency is requiring that 
residential lawns be watered after DCPA product use and that reentry 
not occur until sprays have dried, in an effort to mitigate risks to 
children.
    iii. Re-entry. Risk from exposure to DCPA and HCB through worker 
re-entry into a cucumber field was assessed. Harvesting cucumbers 
immediately after application resulted in risk estimates of 1.8 x 
10-4 for DCPA and 3.2 x 10-4 for HCB. Delayed re-
entry periods only minimally reduced risk estimates. However, the 
Agency reported in the RED that it believes that the worker exposures 
are overestimates. These scenarios were based solely on a foliar 
dissipation study, not on dermal exposure studies. DCPA's current 
registrant is a member of a task force which will address dermal 
exposure for hand labor tasks required by various crops, such as 
cucumber harvesting. The risk assessment will be refined when the task 
force submits it dermal exposure data.

D. Cumulative Effects

     DCPA is a pre-emergent herbicide used to control annual grasses 
and broadleaf weeds. At this time, the EPA has not made a determination 
that DCPA and other substances that may have a common mechanism of 
toxicity would have cumulative effects. Therefore, for these tolerance 
petitions, it is assumed that DCPA does not have a common mechanism of 
toxicity with other substances and only the potential risks of DCPA in 
its aggregate exposure are considered.

E. Safety Determination

     DCPA and its metabolites generally are of low acute and chronic 
toxicity. DCPA has been classified as a Group C, possible human 
carcinogen. Many food crop uses are registered, however, dietary 
exposure to DCPA residues in foods is at a low level, as is the cancer 
risk posed to the general population.
     Of greater concern is the risk posed to DCPA handlers, 
particularly mixers/loaders/applicators, and field workers who come 
into contact with treated areas following application of this 
pesticide. Exposure and risk to workers will be mitigated by the use of 
personal protective equipment required by the Worker Protection 
Standard. Because the pesticide is a possible human carcinogen, the 
Agency required mixer/loader/applicators using DCPA wettable powder to 
wear a dust-mist respirator fitted with a TC-21 filter to mitigate this 
risk.
     Section 4(g)(2)(A) of FIFRA calls for the Agency to determine, 
after submission of relevant data concerning an active ingredient, 
whether products containing the active ingredient are eligible for 
reregistration. The Agency has previously identified and required the 
submission of the generic (i.e., active ingredient specific) data 
required to support reregistration of products containing DCPA. The 
Agency completed its review of these generic data, and determined that 
the data are sufficient to support reregistration of all products 
containing DCPA under the conditions specified in the RED. The generic 
data that the Agency reviewed as part of its determination of 
reregistration eligibility of were sufficient to allow the Agency to 
assess the registered uses of DCPA and to determine that DCPA can be 
used without resulting in unreasonable adverse effects to humans and 
the environment, if used according to the labels as amended by the RED. 
The Agency, therefore, found that all products containing DCPA as the 
active ingredient are eligible for reregistration under the conditions 
specified in the RED.

F. International Tolerances

     No maximum residue limits for DCPA have been established by Codex 
for any agricultural commodity. Therefore, no compatibility questions 
exist with respect to U.S. tolerances.

[FR Doc. 04-10288 Filed 5-5-04; 8:45 am]
BILLING CODE 6560-50-S