[Federal Register Volume 68, Number 225 (Friday, November 21, 2003)]
[Notices]
[Pages 65708-65713]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-29188]


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ENVIRONMENTAL PROTECTION AGENCY

[OPP-2003-0336; FRL-7333-7]


Dichlormid; 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-2003-0336, must be 
received on or before December 22, 2003.

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: Princess Campbell, Registration 
Division (7505C), Office of Pesticide Programs, Environmental 
Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460-
0001; telephone number: (703) 308-8033; 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:
    [sbull] Crop production (NAICS code 111)
    [sbull] Animal production (NAICS code 112)
    [sbull] Food manufacturing (NAICS code 311)
    [sbull] Pesticide manufacturing (NAICS code 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

[[Page 65709]]

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-2003-0336. 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 in paper 
form, 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-2003-0336. 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-2003-0336. 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,

[[Page 65710]]

DC 20460-0001, Attention: Docket ID number OPP-2003-0336.
    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-2003-0336. 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.

List of Subjects

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

    Dated: November 13, 2003.
Debra Edwards,
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 Dow AgroSciences LLC, and represents the view 
of the petitioner. The summary may have been edited by EPA if the 
terminology used was unclear, the summary contained extraneous 
material, or the summary unintentionally made the reader conclude that 
the findings reflected EPA's position and not the position 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.

 Dow AgroSciences LLC

 PP 3E6676

     EPA has received a pesticide petition (3E6676) from Dow 
AgroSciences LLC, 9330 Zionsville Rd., Indianapolis, IN 46268 
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 180.469 by 
establishing time-limited tolerances for residues of dichlormid (N,N-
diallyl dichloroacetamide) (CAS Reg. No. 37764-25-3), in or on sweet 
corn commodities at 0.05 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. A plant metabolism study has now been 
completed. Previously, the nature of the residue in corn was understood 
based on the published metabolism studies of N,N-diallyl-2- 
chloroacetamide. At that time, it was concluded that the metabolism of 
dichlormid would follow the pathway of N,N-diallyl-2-chloroacetamide. 
However, the metabolism of dichlormid in corn is extensive and occurs 
via two metabolic pathways. In one pathway, dichlormid is de-
chlorinated and oxidized to generate N,N-diallyl glycolamide. An 
alternative pathway is the loss of an allyl group followed by oxidation 
to form dichloracetic acid. There is also extensive incorporation into 
natural constituents. Dow AgroSciences LLC now believes that the 
qualitative nature of the residue in plants is adequately understood 
based on a study depicting the metabolism of dichlormid in corn plants.
    2. Analytical method. As stated in the Agency's Final Rule 
published August 7, 2002 (67 FR 51102) (FRL-7192-5) establishing time-
limited tolerances for dichlormid in field corn and pop corn:
    Adequate enforcement methodology is available to enforce the 
tolerance expression. The method may be requested from: Calvin 
Furlow, PRRIB, IRSD (7502C), Office of Pesticide Programs, 
Environmental Protection Agency, Ariel Rios Bldg., 1200 Pennsylvania 
Ave., NW., Washington, DC 20460; telephone number: (703) 305-5229; 
e-mail address: [email protected].

    3. Magnitude of residues. Fourteen field trials in sweet corn with 
dichlormid were conducted covering the major growing areas in the 
United States. Dichlormid was applied preplant incorporated or pre-
emergence at an application rate of 0.5 lb active ingredient (a.i.) per 
acre. In all trials, no detectable residues of dichlormid (LOD 0.01 
ppm) were found in the forage, stover or kernels plus cobs with husks 
removed (K+CWHR)

[[Page 65711]]

B. Toxicological Profile

    1. Acute toxicity. Dichlormid has low acute toxicity as indicated 
by a range of studies including: A rat acute oral study with a lethal 
dose (LD)50 of 2,816 milligrams/kilogram (mg/kg) for males 
and 2,146 mg/kg for females, respectively; a rat acute dermal study 
with an LD50 of >2,040 mg/kg, and a rabbit acute dermal 
study with an LD50 of >5,000 mg/kg; a rat inhalation study 
with an LD50 of >5.5 milligrams/liter (mg/L); a primary eye 
irritation study in the rabbit showing mild ocular irritation; a 
primary dermal irritation study in the rabbit showing severe skin 
irritation; and a skin sensitization study which showed that dichlormid 
was a mild skin sensitizer in the guinea pig.
    2. Genotoxicty. Dichlormid was not mutagenic in a range of in vitro 
assays, including the Salmonella/microsome (Ames) assay, the human 
lymphocyte cytogenetic assay (both assays with and without metabolic 
activation), and an unscheduled DNA synthesis (DNA repair) assay in 
hepatocytes. In the L5178Y mouse lymphoma assay, small increases in 
mutant frequency were observed only at cytotoxic concentrations, and 
were not considered to be significant. In vivo, dichlormid was negative 
in the mouse micronucleus test and in the rat unscheduled DNA synthesis 
assay, when tested at the maximum tolerated dose.
    3. Reproductive and developmental toxicity. In a developmental 
toxicity study, rats were dosed orally by gavage with 0, 10, 40, or 160 
mg/kg/day. The no observed adverse effect level (NOAEL) for maternal 
toxicity was 10 mg/kg/day based on a reduction in body weight gain and 
food consumption at 40 and 160 mg/kg/day. The developmental NOAEL was 
determined to be 40 mg/kg/day based on marginal foetotoxic effects, 
including extra 14th ribs probably due to maternal stress, 
slight sternebra misalignment and some centra unossified, at 160 mg/kg/
day.
     In a developmental toxicity study, rabbits were dosed orally by 
gavage with 0, 5, 30, or 180 mg/kg/day. The lowest observed effect 
level (LOAEL) for both maternal and fetotoxicity was 180 mg/kg/day 
characterized by reduced body weight gain and food consumption, and a 
small increase in post implantation loss, an increased number of early 
resorptions, a decreased number of fetuses per litter and evidence of 
foetotoxicity (partial ossification and misshapen/fused sternebrae). 
The NOAEL for both maternal and developmental toxicity was 30 mg/kg/
day.
     In a two-generation reproduction study in rats fed diets of 0, 15, 
75, and 500 ppm of dichlormid, dietary administration of 500 ppm 
dichlormid (48.5 mg/kg/day) for two successive generations resulted in 
decreased body weights and increased liver weights in parents and pups 
of both generations. There were no effects on reproductive performance 
or reproductive organs at dose levels up to and including 500 ppm 
dichlormid. There were no toxicologically significant effects in 
parents or offspring at a dose level of 75 ppm dichlormid (>7.4 mg/kg/
day).
    4. Subchronic toxicity. In a subchronic toxicity study, groups of 
12 male and 12 female Wistar-derived alpk:ApfSD rats were fed diets 
containing 0, 20, 200, or 2,000 ppm dichlormid for 90 days. Significant 
reductions in body weight gain and food consumption were seen in male 
and female rats receiving 2,000 ppm dichlormid, and to a lesser degree, 
in females at 200 ppm. The liver was identified as the principal target 
organ (enlargement increased APDM activity in females, centrilobular 
hypertrophy, increased bile duct pigmentation) in the 2,000 ppm group. 
The NOAEL was 20 ppm (equivalent to approximately 1.8 mg/kg/day), and 
the LOAEL was 200 ppm based on reduced body weight gain and food 
consumption, and a marginal increase in APDM activity in females and 
liver enlargement in males.
     In a 90-day dog feeding study, previously submitted and reviewed 
by EPA, animals were dosed (4 dogs/sex/dose) at 0, 1, 5, 25, and 50 mg/
kg/day. The NOAEL was 5 mg/kg/day, and the LOAEL 25 mg/kg/day based on 
reduced body weight gain, increased liver weight and degenerative 
changes involuntary muscle with an associated increase in plasma 
creatine kinase and alkaline phosphatase activity between 6 and 10 
weeks.
     In a 14-week rat inhalation study, groups of 18 male and 18 female 
Sprague-Dawley CD rats were subjected to a whole body exposure of 0, 
2.0, 19.9, or 192.5 mg/m3 for 6 hours per day, 5 days per 
week. The NOAEL was 2.0 mg/m3 based on histopathologic 
tissue alterations to the nasal olfactory epithelium at 19.9 and 192.5 
mg/m3, suggesting that dichlormid was a mild irritant to the 
nasal cavity. An increase in relative liver, kidney and lung weights at 
19.9 and 192.5 mg/m3 was not supported by gross or 
histopathological observations.
    5. Chronic toxicity. Rats (64/sex/group) were fed diets containing 
0, 20, 100, or 500 ppm dichlormid (0, 1.3, 6.5, 32.8 mg/kg/day for 
males and 0, 1.5, 7.5, 37.1 mg/kg/day for females) for up to 2 years. 
At 500 ppm in both males and females, there were treatment-related 
effects on growth and food consumption, minor reductions in plasma 
triglycerides, and in males, increased liver weights accompanied by 
hepatocyte vacuolation and pigmentation effects. In females, there was 
a slight overall increase in malignant tumors, primarily uterine 
adenocarcinomas, at 500 ppm, but this specific increase was within the 
spontaneous incidence observed in historical data. It was concluded 
that there was no evidence of oncogenicity associated with dichlormid 
treatment. The NOAEL for chronic toxicity was 100 ppm (6.5 and 7.5 mg/
kg/day for males and females, respectively).
     In an 18-month oncogenicity study, mice (55/sex/group) were fed 
dichlormid at doses of 0, 10, 50, or 500 ppm (0, 1.4, 7.0, 70.7 mg/kg 
for males and 0, 1.84, 9.2, 92.4 mg/kg for females). At 500 ppm, there 
was a slight increase in mortality for females from week 64 onward, and 
body weights and food utilization were reduced in males, and to a 
lesser extent, in females. Also, mice fed 500 ppm dichlormid showed 
non-neoplastic changes which were minor and consisted of changes in 
severity or incidence of common spontaneous findings. Based on these 
effects, the chronic NOAEL was 50 ppm (7.0 and 9.2 mg/kg/day for males 
and females, respectively). There was a marginal increase in Harderian 
gland adenomas in males at 500 ppm, but this was considered to reflect 
the variable spontaneous tumor rate seen in this strain and sex of 
mouse. It was concluded there was no evidence of oncogenicity 
associated with dichlormid treatment.
     Based on available chronic toxicity data, the reference dose (RfD) 
for dichlormid is 0.07 mg/kg/day. This RfD is based on the 2-year 
feeding study in rats with a NOAEL of 7 mg/kg/day. An uncertainty 
factor of 100 was used to account for interspecies extrapolation and 
intraspecies variability. The 2-year rat study is consistent with, but 
supersedes the 90-day rat study. The 2-year rat NOAEL of 7 mg/kg/day 
lies between 1.8 and 18 mg/kg/day derived from the NOAEL and LOAEL 
figures of 20 and 200 ppm, respectively, for the most recent 90-day rat 
study. Thus, the overall NOAEL in the rat for both chronic and 
subchronic exposure should be regarded as 7 mg/kg/day. Based on the 
proposed Guidelines for Carcinogenic Risk Assessment (July 1999), 
dichlormid is not likely to be a human carcinogen, and a margin of 
exposure (MOE) approach should be used for human risk assessment.

[[Page 65712]]

    6. Animal metabolism. Dichlormid was well absorbed, extensively 
metabolized and eliminated mainly in the urine within 24 hours. A 
significant proportion of the dose, up to 11%, was exhaled as 
CO2. Two routes of biotransformation have been identified. 
One route involved the formation of an alcohol N,N-diallylglycolamide 
before subsequent oxidation to N,N-diallyloxamic acid, a major 
metabolite present in the urine and feces of both sexes. N,N-
diallylglycolamide also undergoes further biotransformation to minor 
dechlorinated metabolites. In the second metabolic pathway, 
dichloroacetic acid present in the urine of both sexes is formed either 
directly from dichlormid or indirectly by transformation of N-allyl-
2,2-dichloro-N-(2,3-dihydroxypropyl)acetamide. Entero-hepatic 
recirculation plays a major role in the distribution, metabolism and 
excretion of dichlormid. The elimination as CO2, the even 
elimination in urine over the first 24 hours, and wide distribution of 
retained radioactivity indicates some incorporation into endogenous 
metabolic processes.
    7. Metabolite toxicology. No unique plant or soil metabolites have 
been identified that warrant a separate toxicological assessment.
    8. Endocrine disruption. There is no overall trend in the 
toxicology data base that indicates that dichlormid would have 
endocrine disrupting activity. The mammalian and ecotoxicology data 
bases do not indicate significant adverse effects associated with 
endocrine disrupter activity.

C. Aggregate Exposure

    1. Dietary--i. Food. In conducting a chronic dietary risk 
assessment, reference is made to the conservative assumptions made by 
EPA in establishing dichlormid time-limited tolerances on March 27, 
2000 (65 FR 16143) (FRL-6498-7), 100% crop treated (CT), and that all 
commodities contain residues at the tolerance or proposed tolerance. 
The analysis was determined using the Novigen Dietary Exposure 
Evaluation Model (DEEM Version 6.2) software and the United States 
Department of Agriculture (USDA) nationwide Continuing Surveys of Food 
Intake by Individuals (CSFII) survey that was conducted from 1994 
through 1996.
    ii. Drinking water. Dichlormid is very rapidly degraded in soil 
(laboratory measured aerobic half-life of 8 days) and applied at a 
maximum rate of 0.5 lb/acre, so despite only exhibiting moderate 
adsorption to soil (Koc 36-49), the leaching potential for dichlormid 
to reach ground water is expected to be low. The impact of the 
interactive processes of adsorption and degradation on leaching have 
been assessed using EPA mathematical models of pesticide movement in 
soil. Drinking water estimate concentrations (DWEC) were calculated for 
ground water using Screening Concentration in Ground water (SCI-GROW) 
modeling, and surface water estimate concentrations were calculated 
using Generic Estimated Environmental Concentration (GENEEC) modeling. 
These models predict a ground water concentration of 0.05 ppb and 
surface water concentrations of 27.3 parts per billion (ppb) for an 
instantaneous peak, and 26.9 ppb for a 56-day average. However, the 
interim Agency policy allows the average 56-day GENEEC values to be 
divided by 3 (9.0 ppb) to obtain a value for chronic risk assessments. 
Drinking water levels of concern (DWLOC) were calculated for both 
chronic and acute exposure. As stated in the March 27, 2000 final rule:

    . . .the modeled groundwater and surface water concentrations 
are less than the DWLOCs for dichlormid in drinking water for acute 
and chronic aggregate exposures. Thus, the Agency is able to screen 
out dichlormid drinking water risks.

    Dow AgroSciences LLC does not expect exposure to dichlormid 
residues in drinking water to be a concern, as a result of the 
increased exposure pattern.
    2. Non-dietary exposure. The general population is not expected to 
be exposed to dichlormid through non-dietary routes since dichlormid is 
used only on agricultural crops and is not used in or around the home.

D. Cumulative Effects

     The potential for cumulative effects of dichlormid and other 
substances that have a common mechanism of toxicity have been 
considered. There is no reliable information to suggest that dichlormid 
has any toxic effects that arise from toxic mechanisms common to other 
substances. Therefore, a consideration of common mechanism and 
cumulative effects with other substances is not appropriate for 
dichlormid.

E. Safety Determination

    1. U.S. population--i. Chronic risk. Using the conservative 
exposure assumptions described earlier, and based on the completeness 
and reliability of the toxicity data base for dichlormid, the 
theoretical maximum residue concentration (TMRC) for the general U.S. 
population is calculated to be 0.0009 mg/kg/day, or 4.1% of the cPAD 
(0.0022 mg/kg/day). The most highly exposed subgroup are children aged 
1-6 years with a TMRC of 0.000211 mg/kg/day, or 9.6% of the cPAD. As 
EPA generally has no concern for exposures below 100% of the RfD 
because the RfD represents the level at or below which daily aggregate 
dietary exposure over a lifetime will not pose appreciable risks to 
human health, Dow AgroSciences LLC believes that there is a reasonable 
certainty that no harm will result from aggregate exposure to 
dichlormid residues.
    ii. Acute risk. The acute toxicity of dichlormid is low, and there 
are no concerns for acute-dietary, occupational or non-occupational 
exposures to dichlormid.
    2. Infants and children. In assessing the potential for additional 
sensitivity of infants and children to residues of dichlormid, data 
from developmental toxicity studies in the rat and rabbit have been 
considered. The developmental toxicity studies are designed to evaluate 
adverse effects on the developing organism resulting from maternal 
pesticide exposure during gestation. There was no evidence to suggest 
that dichlormid was a developmental toxicant in either the rat or 
rabbit. It was also observed that there was no risk below maternally 
toxic doses as the NOAEL for developmental effects in the rat was 40 
mg/kg/day, compared to the maternal NOAEL of 10 mg/kg/day; and in the 
rabbit study, the NOAEL for both maternal and developmental effects was 
30 mg/kg/day. EPA has previously concluded, that the additional 10x 
safety factor should be retained due to the qualitative evidence of 
increased susceptibility demonstrated following in utero exposure in 
the prenatal developmental toxicity in rabbits and an incomplete 
toxicity data base. It should be noted that in the rabbit developmental 
toxicity study, the LOAEL for both maternal and developmental toxicity 
was 180 mg/kg/day. The effects on resorptions at this dose were 
observed in dams which showed an average weight loss (-3.8g) during the 
treatment period compared with an average weight gain in controls of 
272g. Also, a multigeneration study has now been completed, and 
therefore, Dow AgroSciences LLC believes that an additional safety 
factor should no longer be necessary.
     Additional uncertainty factors are not warranted for the safety of 
infants and children as reliable data support the appropriate use of a 
100-fold uncertainty factor margin of exposure (MOE) to account for 
interspecies extrapolation and intraspecies variability. However, using 
the conservative exposure assumptions above for the determination in 
the

[[Page 65713]]

general population, it is concluded that the percentage of cPAD that 
will be utilized by aggregate exposure to dichlormid is 9.6% for 
children aged 1-6 years (the group at highest risk). Therefore, based 
on the completeness and reliability of the toxicity data base and the 
conservative exposure assessment, Dow AgroSciences LLC, concludes that 
there is a reasonable certainty that no harm will result to infants and 
children from aggregate exposure to dichlormid residues.

F. International Tolerances

     There is neither a codex proposal nor Canadian or Mexican limits 
for residues of dichlormid in corn commodities.
[FR Doc. 03-29188 Filed 11-20-03; 8:45 am]
BILLING CODE 6560-50-S