Dichlormid; Notice of Filing a Pesticide Petition to Establish a Tolerance for a Certain Pesticide Chemical in or on Food, 8806-8811 [05-3361]

Agencies

• ENVIRONMENTAL PROTECTION AGENCY

[Federal Register Volume 70, Number 35 (Wednesday, February 23, 2005)]
[Notices]
[Pages 8806-8811]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 05-3361]


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ENVIRONMENTAL PROTECTION AGENCY

[OPP-2005-0023; FRL-7698-8]


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 identification (ID) number OPP-
2005-0023, must be received on or before March 25, 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: Keri Grinstead, Registration Division 
(7505C), Office of Pesticide Programs, Environmental Protection Agency, 
1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone 
number:

[[Page 8807]]

(703) 308-8373; e-mail address: grinstead.keri@epa.gov.

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this Action Apply to Me?

     You may be potentially affected by this action if you 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. Docket. EPA has established an official public docket for this 
action under docket ID number OPP-2005-0023. 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 https://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 https://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 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 https://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-2005-0023. 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,

[[Page 8808]]

Attention: Docket ID number OPP-2005-0023. 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-2005-0023.
    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-2005-0023. 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: February 10, 2005.
Lois Rossi,
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 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 4F6858

     EPA has received a pesticide petition (PP 4F6858) from Dow 
AgroSciences LLC, 9330 Zionsville Road, 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 part 180, by 
establishing a tolerance for residues of dichlormid in or on the raw 
agricultural commodity corn (forage, grain, stover) 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 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 a study depicting the 
metabolism of dichlormid in corn plants. The metabolism of dichlormid 
in corn is extensive and occurs via two metabolite pathways. In one 
pathway dichlormid is de-chlorinated and oxidised to generate N,N-
diallyl glycolamide. An alternative pathway is the loss of an allyl 
group followed by oxidation to form dichloroacetic acid. There is also 
extensive incorporation into natural constituents. EPA has previously 
determined that dichlormid is the residue of concern for tolerance 
setting purposes.
    2. Analytical method. An adequate enforcement method for residues 
of dichlormid in corn has been developed and validated by the 
Analytical Chemical Laboratory (ACL) of EPA. Analysis is carried out 
using gas chromatography with nitrogen selective thermionic detection. 
The limit of determination is 0.01 ppm.
    3. Magnitude of residues. Fifteen (15) field trials in field corn 
with dichlormid were submitted and reviewed. The submitted data support 
the tolerance

[[Page 8809]]

level of 0.05 parts per million (ppm) for all corn commodities.

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 an 
LD50 of 2,816 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.
     An acute neurotoxicity study was conducted in rats and a single 
oral administration of 1,500 mg dichlormid/kg was not associated with 
any histopathological changes and no functional changes indicative of 
neurotoxicity. The NOAEL for neurotoxicity in this study was 1,500 mg 
dichlormid/kg.
    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 
fetotoxicity (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 - see 
discussion under Chronic toxicity, Section B.5.), 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.
     A subchronic neurotoxicity study was conducted in rats and groups 
of male and females rats were fed diets containing 0, 100, 250, or 750 
ppm dichlormid for 90-days. There were no compound related effects in 
either sex throughout the study and there was no evidence of 
neurotoxicity. The NOEL for neurotoxicity was 750 ppm (55.4 mg/kg bwt/
day for males, 61.2 mg/kg bodyn weight (bwt/day for females).
    5. Chronic toxicity. A 1-year chronic toxicity study was conducted 
in dogs with a NOAEL of 5 mg dichlormid/kg bwt/day for both males and 
females. The LOAEL from this study was 20 mg dichlormid/kg bwt/day 
based on minimal muscle fiber degeneration and slight to moderate 
vacuolation of the adrenal cortex. Adaptive changes consisting of 
increased plasma alkaline phosphatase activity and increased liver 
weights, were present at this dose level. There were no other signs of 
overt 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 vaculolation 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

[[Page 8810]]

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 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 of 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.
    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 database that indicates that dichlormid would have endocrine 
disrupting activity. The mammalian and ecotoxicology databases do not 
indicate significant adverse effects associated with endocrine 
disrupter activity.

C. Aggregate Exposure

    1. Dietary exposure--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 groundwater 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 
groundwater using Screening Concentration in Groundwater (SCI-GROW) 
modeling and surface water estimate concentrations were calculated 
using Generic Estimated Environmental Concentration (GENEEC) modeling. 
These models predict a groundwater concentration of 0.05 ppb and 
surfacewater concentrations of 27.3 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 
surfacewater 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.
    3. 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.

D. 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 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

[[Page 8811]]

mg/kg/day; and in the rabbit study, the NOEL 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 (MOE) to account for interspecies 
extrapolation and intraspecies variability. However, using the 
conservative exposure assumptions above for the determination in the 
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.

E. International Tolerances

     There is neither a codex proposal nor Canadian or Mexican limits 
for residues of dichlormid in corn commodities.
[FR Doc. 05-3361 Filed 2-22-05; 8:45 am]
BILLING CODE 6560-50-S