Jump to main content.


Propamocarb Hydrochloride; Notice of Filing a Pesticide Petition to Establish a Tolerance for a Certain Pesticide Chemical in or on Food

Note: EPA no longer updates this information, but it may be useful as a reference or resource.


 
[Federal Register: March 10, 2004 (Volume 69, Number 47)]
[Notices]
[Page 11426-11431]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr10mr04-70]

-----------------------------------------------------------------------

ENVIRONMENTAL PROTECTION AGENCY
[OPP-2003-0414; FRL-7340-7]
 
Propamocarb Hydrochloride; 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.

-----------------------------------------------------------------------

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-
2003-0414, must be received on or before April 9, 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: Mary Waller, Registration Division 
(7505C), Office of Pesticide Programs, Environmental Protection Agency, 
1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone 
number: (703) 308-9354; e-mail address: waller.mary@epa.gov.

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this Action Apply to Me?

    You may be potentially affected by this action if you are an 
agricultural producer, food manufacturer, or 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-2003-0414. 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

[[Page 11427]]

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.regulations.gov/ 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 EPA's 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.1. 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, 
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-2003-0414. The system is an ``anonymous access'' system, which 
means EPA will not know your identity, e-mail address, or other contact 
information unless you provide it in the body of your comment.
    ii. E-mail. Comments may be sent by e-mail to opp-docket@epa.gov, 
Attention: Docket ID Number OPP-2003-0414. 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-2003-0414.
    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-2003-0414. 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

[[Page 11428]]

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 27, 2004.
 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 the petitioner and represents the view of the petitioner. 
The petition summary announces the availability of a description of the 
analytical methods available to EPA for the detection and measurement 
of the pesticide chemical residues or an explanation of why no such 
method is needed.

Bayer CropScience

PP 0F6123

    EPA has received a pesticide petition (0F6123) from Bayer 
CropScience, 2TW Alexander Drive, Research Triangle Park, NC 27709, 
proposing, pursuant to section 408(d) of the FFDCA, 21 U.S.C. 346a(d), 
to amend 40 CFR 180.499 by establishing a tolerance for residues of 
propyl [3-(dimethylamino)propyl]carbamate mono-hydrochloride, also 
known as propamocarb hydrochloride, in or on the raw agricultural 
commodities (RACs) lettuce, leaf, at 65 parts per million (ppm), 
lettuce, head, at 50 ppm, wheat, grain, at 0.05 ppm, wheat, straw, at 
0.10 ppm, wheat, forage, at 0.30 ppm, wheat, hay, at 0.30 ppm, 
vegetable, cucurbit, group 9, at 1.5 ppm, vegetable, fruiting, group 8, 
at 2.0 ppm, and tomato, paste, at 5.0 ppm. EPA has determined that the 
petition contains data or information regarding the elements set forth 
in section 408(d)(2) of the FFDCA; however, EPA has not fully evaluated 
the sufficiency of the submitted data at this time or whether the data 
support granting of the petition. Additional data may be needed before 
EPA rules on the petition.

A. Residue Chemistry

    1. Plant metabolism. The fate of propamocarb hydrochloride in 
plants is clearly understood. Metabolism studies in cucumbers, 
potatoes, and spinach demonstrated that propamocarb hydrochloride is 
degraded into carbon dioxide, which is reincorporated into natural 
plant constituents. The primary residue found in all crops, and the 
only residue of concern, is the parent, propamocarb hydrochloride.
    2. Analytical method. A practical analytical method utilizing gas/
liquid chromatography (GLC) and flame ionization detector N-(FID) or 
mass spectrometry detection (MSD) is available and has been validated 
for detecting and measuring levels of propamocarb hydrochloride in or 
on food. The limit of quantification (LOQ) is 0.05 milligrams/kilogram 
(mg/kg) (ppm).
    3. Magnitude of residues. Residue trials have been conducted with 
representative applications of propamocarb hydrochloride formulations 
to lettuce, cucurbits, tomatoes, and peppers. In all cases, the 
proposed tolerances are based upon the highest residues seen at the 
maximum rate, minimum application interval, and minimum pre-harvest 
interval utilized in the studies.
    For lettuce, leaf, a proposed pre-harvest interval of 2 days and 
tolerance of 65 ppm is proposed. For lettuce, head, a pre-harvest 
interval of 2 days and tolerance of 50 ppm is proposed. For vegetables, 
cucurbits, a proposed pre-harvest interval of 2 days and tolerance of 
1.5 ppm is proposed. For vegetables, fruiting, a pre-harvest interval 
of 5 days and tolerance of 2.0 ppm is proposed. Based on a tomato 
processing study, a tolerance of 5.0 ppm is proposed for tomato paste. 
No tolerance is proposed for tomato, puree, because the residue in this 
commodity is anticipated to be less than or equal to the proposed crop 
group tolerance.
    In the field rotational crop study, residues were present only in 
wheat rotated 30 days after the last propamocarb hydrochloride 
treatment. There were no residues in sugar or table beets, soybeans, or 
dried beans. Based upon the results of this study, and in conjunction 
with recent section 18 emergency exemptions, EPA proposed time-limited 
tolerances for wheat grain at 0.05 ppm (the LOQ of the analytical 
method), wheat straw at 0.1 ppm, and wheat forage and hay at 0.3 ppm.

B. Toxicological Profile

    Much of the toxicological database supporting the registration of 
propamocarb hydrochloride has been evaluated by EPA as part of previous 
regulatory actions and is summarized below. The conclusions presented 
are those determined by the Agency as reported by the registrant. 
Additional studies have been submitted to the Agency and are awaiting 
review. Those studies' results are summarized below by the registrant.
    1. Acute toxicity. There are no acute toxicity concerns with 
propamocarb hydrochloride. The acute rat oral lethal dose 
(LD)50 was 2,900 mg/kg in males and 2,000 mg/kg in females. 
The acute rat dermal (LD)50 was >3,000 mg/kg. The acute (4-
hour) inhalation lethal

[[Page 11429]]

concentration (LC)50 in rats was >5.54 milligrams/Liter (mg/
L). Propamocarb hydrochloride was a slight skin sensitizer in guinea 
pigs. Propamocarb hydrochloride was previously classified as toxicity 
category III for acute oral and dermal toxicity and eye irritation, and 
category IV for acute inhalation toxicity and skin irritation.
    An acute neurotoxicity study was performed in rats at dose levels 
of 0, 20, 200, and 2,000 mg/kg of propamocarb hydrochloride. The 
overall no observed adverse effect level (NOAEL) for this study was 
determined to be 200 mg/kg based on decreased weight gain, soiled fur 
and decreased motor activity in males and/or females at 2,000 mg/kg.
    2. Genotoxicity. No evidence of genotoxicity was observed in a 
battery of studies including Salmonella and E. coli gene mutation 
assays, two mouse micronucleus assays, an in vitro mammalian 
cytogenetic assay using cultured human lymphocytes, a yeast mitotic 
gene conversion assay and a yeast mitotic recombination assay.
    3. Reproductive and developmental toxicity. In a developmental 
toxicity study, rats were administered propamocarb hydrochloride by 
gavage at dose levels of 0, 74, 221, 740, or 2,210 mg/kg/day on 
gestation days 6-19. The NOAEL for maternal toxicity was 740 mg/kg/day 
based on mortality, clinical observations and decreased body weight 
gain at 221 mg/kg/day. The NOAEL for developmental toxicity was 221 mg/
kg/day based on increased post-implantation loss, decreased fetal 
weights and increased incidence of minor skeletal anomalies (retarded 
ossification) at 740 and/or 2,210 mg/kg/day.
    In another developmental toxicity study, rabbits were administered 
propamocarb hydrochloride by gavage at dose levels of 0, 15, 45, 150, 
300, or 600 mg/kg/day on gestation days 6-18. The NOAEL for both 
maternal toxicity and developmental toxicity was 150 mg/kg/day, based 
on decreased maternal body weight gain and increased post-implantation 
loss at 300 mg/kg/day.
    A 3-generation reproduction study was conducted using rats fed 
diets containing propamocarb hydrochloride at dietary concentrations of 
0, 40, 200, and 1,000 ppm (33.3 mg/kg/day) for 100 days and then 
continuously through three successive generations. No treatment-related 
effects were noted on either the parents or offspring.
    A 2-generation reproduction study was conducted with albino rats. 
Animals received propamocarb hydrochloride at dietary concentrations of 
0, 200, 1,250 and 8,000 ppm. Reduced body weights were observed in the 
F0 and F1 parental animals and the F1 and F2 offspring at 8,000 ppm. 
Based on these findings, the NOAEL is 1,250 ppm for parental and 
neonatal toxicity (81 mg/kg/day for males and 127 mg/kg/day for 
females) and 8,000 ppm for reproductive toxicity.
    4. Subchronic toxicity. In a 90-day feeding study, propamocarb 
hydrochloride was administered to albino rats at concentrations of 0, 
20, 50, 100, and 500/1,000 ppm. (The high dose rate was 500 ppm when 
the study was begun, but was raised to 1,000 ppm during the course of 
the study) in the diet. The only effects noted were slightly reduced 
food efficiency and body weight gains at 1,000 ppm.
    In a 90-day feeding study in Beagle dogs, propamocarb hydrochloride 
was administered in the diet at concentrations of 0, 50, 100, 500, and 
1,000/2,000 ppm. (The high dose rate was 1,000 ppm when the study was 
begun, but was raised to 2,000 ppm during the course of the study). No 
treatment-related findings were observed.
    In a 90-day feeding study with albino mice, propamocarb 
hydrochloride was administered at concentrations of 0, 1,404, 2,808, 
5,616 and 11,232 ppm in the diet. No treatment-related findings were 
observed.
    A 21-day dermal toxicity study was performed with propamocarb 
hydrochloride in Sprague-Dawley rats at dose levels of 0, 100, 500, and 
1,000 mg/kg/day, 6 hours per day, 5 days per week over a 21-day period. 
No treatment related effects were observed.
    A 21-day dermal toxicity study was performed with propamocarb 
hydrochloride in rabbits at dose levels of 0, 150, 525, and 1,500 mg/
kg/day, 6 hours per day, 5 days per week, over a 21-day period. The 
NOAEL for this study was considered by the Agency to be 150 mg/kg/day 
based on dose-related skin irritation in mid-dose and high-dose animals 
and a decrease in weight gain in mid-dose females.
    A 90-day neurotoxicity study was conducted in rats at dietary 
concentrations of propamocarb hydrochloride of 0, 200, 2,000, and 
20,000 ppm. No evidence of neurotoxicity (Functional Obervation Battery 
(FOB), motor activity or neuropathology) was observed at any dose 
level. Plasma, red blood cell (RBC) and brain cholinesterase levels 
were also not affected. The NOAEL was determined to be 2,000 ppm (142 
mg/kg/day) based on decreased weight gain at 20,000 ppm.
    5. Chronic toxicity. A 2-year feeding chronic toxicity/
carcinogenicity study was performed in Sprague-Dawley rats with 
propamocarb hydrochloride at dietary concentrations of 0, 40, 200, or 
1,000 ppm. There was no evidence of carcinogenicity or other treatment-
related effects except for a possible reduction in food intake in 
female rats at the highest level tested. Thus, 1,000 ppm (41 mg/kg/day) 
was considered to be the NOAEL. However, this study did not satisfy the 
EPA's criteria for a maximum tolerated dose (MTD). In a second 2-year 
chronic toxicity/oncogenicity study, albino rats received diets 
containing propamocarb hydrochloride at concentrations of 0, 350, 
2,800, and 22,400 ppm. Animals receiving 22,400 ppm exhibited decreased 
body weights, body weight gain and food consumption. Additionally, 
these animals revealed moderate vacuolation of the choroid plexus 
ependymal cells. There was no evidence of oncogenicity. Based on these 
findings, the NOAEL is 2,800 ppm (138 mg/kg/day).
    A 2-year feeding chronic toxicity/carcinogenicity study was 
performed in CD-1 mice with propamocarb hydrochloride at dietary 
concentrations of 0, 20, 100, and 500 ppm. No evidence of 
carcinogenicity or toxicity was noted at any dose level. Thus, 1,000 
ppm (53 mg/kg/day for males and females, respectively), was considered 
to be the NOAEL.
    An 18-month mouse oncogenicity study was conducted in CD-1 mice 
exposed to propamocarb hydrochloride at dietary concentrations of 0, 
105, 840, and 6,720 ppm. Reduced body weights were reported for animals 
in the 840 and 6,720 ppm groups. There was no evidence of oncogenicity. 
Based on these findings, the NOAEL is 105 ppm (16 mg/kg/day).
    A 2-year feeding study was performed in Beagle dogs with 
propamocarb hydrochloride at dietary concentrations of 0, 1,000, 3,000, 
and 10,000 ppm. Decreased weight gain, decreased food efficiency, an 
increased incidence of acute gastric mucosal erosions, and/or chronic 
erosive gastritis were noted in all treated groups. Thus, a NOAEL for 
this study was not determined but was considered to be slightly lower 
than the lowest dose level tested (33.3 mg/kg/day, 1,000 ppm).
    6. Animal metabolism. The absorption, distribution, metabolism, and 
excretion of propamocarb hydrochloride has been evaluated in rats. 
Propamocarb hydrochloride was rapidly absorbed, extensively 
metabolized, and rapidly eliminated, primarily via the urine (>90% 
excreted within 24 hours), following oral administration. Metabolite 
profiles were similar following single and repeated

[[Page 11430]]

oral dosing and following intravenous dosing. The primary route of 
metabolism was oxidative degradation with hydrolytic cleavage occurring 
as a secondary pathway.
    The metabolism of propamocarb hydrochloride has been evaluated in 
ruminants. The majority of the orally administered dose was excreted 
via the urine and feces. Total radioactive residues in tissues and bile 
accounted for 0.7% of the administered dose. The majority of the 
residue was comprised of propamocarb hydrochloride plus N-oxide 
metabolite, an oxazolidine metabolite, and a 2-hydroxy metabolite.
    7. Endocrine disruption. No special studies have been conducted to 
investigate the potential of propamocarb hydrochloride to induce 
estrogenic or other endocrine effects. However, the standard battery of 
required toxicity studies has been completed. These studies include an 
evaluation of the potential effects on reproduction and development, 
and an evaluation of the pathology of the endocrine organs following 
repeated or long-term exposure. These studies are generally considered 
to be sufficient to detect any endocrine effects yet no such effects 
were detected. Thus, the potential for propamocarb hydrochloride to 
produce any significant endocrine effects is considered to be minimal.

C. Aggregate Exposure

    An aggregate exposure assessment was conducted in order to 
determine the total exposure for someone who would be exposed to 
propamocarb hydrochloride residues from both dietary and non-dietary 
routes. The only population subgroup of concern for residential use is 
females 13+, thus an aggregate assessment was conducted for this 
subgroup only. For the purpose of this petition only, a worst-case 
scenario was assumed wherein a female 13+ is exposed to an acute 
dietary dose (95\th\ percentile of Tier I analysis) and enters a 
treated residential lawn on the same day (exposure assumptions 
described below). In practice, the aggregate assessment should not 
assume that ``worst-case'' exposures would occur simultaneously. 
Rather, the aggregate assessment should evaluate a realistic scenario 
incorporating the relative application times and use patterns 
(calendar-based model) along with a chronic dietary background 
exposure. This calendar-based model has not been used for this 
assessment. The aggregate methodology used here entails summation of 
all route-specific exposures assuming that they occur simultaneously. 
The dermal non-dietary exposure has been converted to oral equivalents 
using a dermal absorption factor. Thus the maximum aggregate exposure 
for a female 13+ to potential residues of propamocarb hydrochloride 
from food and non-dietary routes is at 11% (0.168 milligrams/kilogram 
of bodyweight per day (mg/kg bwt/day)) of the short-term reference dose 
(RfD) margin of exposure ((MOE)=891). Intermediate-term exposures would 
be even less. The drinking water level of comparison (DWLOC) based on 
this exposure value for females 13+ is 39,900 parts per billion (ppb) 
(39.9 ppb), still several orders of magnitude higher than the acute and 
chronic drinking water estimated concentrations (DWECs) described below.
    1. Dietary exposure. Dietary exposure to propamocarb hydrochloride 
was estimated from residues expected on food and in drinking water.
    i. Food. Potential dietary exposures from food were estimated using 
the dietary exposure evaluation model (DEEM) software system (Novigen 
Sciences, Inc.) and the 1994-1996 United States Department of 
Agriculture (USDA) consumption data. For the purposes of this 
assessment, Bayer CropScience has made the very conservative assumption 
that 100% of all commodities will contain propamocarb hydrochloride 
residues at the proposed and established tolerance levels. EPA has 
established a tolerance for propamocarb hydrochloride on potatoes of 
0.06 ppm [65 FR 58399]. In the current petition the following 
tolerances are proposed: 2.0 ppm in fruiting vegetables and their 
respective processed commodities, except for 5.0 ppm in tomato paste; 
1.5 ppm in cucurbits; 50 ppm in head lettuce; 65 ppm in leaf lettuce; 
0.05 ppm in wheat grain; 0.1 ppm in wheat straw; and 0.3 ppm in wheat 
forage and hay. Results of the Tier I acute analysis for females 13+ 
show that 7% (0.0984 mg/kg body weight/day (bwt/day) of the acute RfD 
is utilized at the 95\th\ percentile. This is a very conservative 
estimate and actual exposure is likely to be much less or negligible in 
real world situations. The Tier I chronic analysis results in 18% 
(0.0201 mg/kg bwt/day of the chronic RfD utilized for the U.S. 
population. The most highly exposed population subgroup is children 1 
to 6 at 24% of the chronic RfD (0.0268 mg/kg bwt/day) consumed. As in 
the acute scenario these are very conservative estimates and actual 
exposures are likely to be much less as new data and models are developed.
    ii. Drinking water. EPA's standard operating procedure (SOP) for 
drinking water exposure and risk assessments was used to perform the 
drinking water assessment. This SOP uses a variety of tools to conduct 
drinking water assessments. These tools include water models such as 
screening concentration in ground water (SCI-GROW), generic expected 
environmental concentration (GENEEC), EPA's Pesticide Root Zone Model/
Exposure Analysis Modeling System (PRZMS/EXAMS), and monitoring data. 
If monitoring data is not available then the models are used to predict 
potential residues in surface water and ground water. In the case of 
propamocarb hydrochloride, monitoring data do not exist therefore SCI-
GROW and PRZM/EXAMS were used to estimate water residues. The 
calculated drinking water level of comparison (DWLOC) for chronic and 
acute exposures for all adults and children exceed the DWEC from the 
models. The acute DWLOC for females 13+ (the only population of concern 
for acute exposure) is 42,000 ppb (42 ppb). The acute DWEC is 132 ppb 
for surface water. The chronic DWLOC for adults is 3,147 ppb. The 
chronic DWLOC for children/toddlers is 833 ppb. The surface water DWEC 
for the worst-case chronic scenario is 20 ppb.
    2. Non-dietary exposure. Based on the labeled use patterns, a 
chronic exposure scenario does not exist. The endpoint of concern is 
short-term and intermediate-term dermal exposure to females 13+ only 
(based on post-implantation loss in the rabbit developmental toxicity 
study). The estimated dermal exposures are converted to oral 
equivalents using a dermal absorption factor. As a professional use 
turf and ornamental fungicide, propamocarb hydrochloride is used 
primarily (>90% of use) on golf courses for control of Pythium blight 
(BANOL Fungicide, EPA Reg. No. 45639-88). Some limited use of BANOL 
occurs on ornamental plants produced in greenhouses or containers, and 
to a very limited extent on sod farms or by professional lawn care 
applicators to commercial turf. No homeowner applicator exposures were 
assessed as the product is not sold to homeowners and only professional 
application would occur. There is the potential for residential post-
application exposure to adults and children entering treated sites in 
recreational areas. No assessments for adult males and toddlers were 
done since the endpoint of concern is for females 13+ only. Using 
screening level conditions proposed in EPA's SOP for Residential 
Exposure Assessments (December 1997, EPA) and the proposed changes to 
the SOP (September, 1999, EPA), short-term exposure and risk were 
estimated for residential adult females. A dermal

[[Page 11431]]

absorption factor of 12% from a dermal penetration study in rats 
submitted by Bayer (MRID #44538505) was used. Based on the 
assumptions below and the default factors from the SOP, a MOE of 2,299 
(Exp=0.07 mg/kg/day) is obtained for adult females. This is well above 
the level of concern (LOC) for propamocarb hydrochloride based on a MOE 
of 100. This analysis is a very conservative estimate based on EPA 
screening level procedures. Actual exposures are likely to be much 
lower, if they occur at all.

D. Cumulative Effects

    Section 408(b)(2)(D)(v) requires that, when considering whether to 
establish, modify, or revoke a tolerance, the Agency consider 
``available information'' concerning the cumulative effects of a 
particular pesticide's residues and ``other substances that have a 
common mechanism of toxicity.'' The precise mechanism of toxicity for 
propamocarb hydrochloride is unknown. Although a member of the 
carbamate group of pesticides, propamocarb hydrochloride is not an n-
methyl carbamate, and demonstrated no inhibitory effects on blood or 
brain cholinesterase following either acute or repeated oral 
administrations to rats and dogs. In vitro studies using rat or dog 
blood plasma showed very slight cholinesterase inhibitory effects only 
at extremely high dose levels, equivalent to about 2,200 mg/kg 
bodyweight. This level is 20,000X the established RfD for propamocarb 
hydrochloride. Thus, no cumulative effects with other carbamates are 
anticipated. There is no other available data to determine whether 
propamocarb hydrochloride has a common mechanism of toxicity with other 
substances or how to include this pesticide in a cumulative risk 
assessment. Unlike other pesticides for which EPA has followed a 
cumulative risk approach based on a common mechanism of toxicity, 
propamocarb hydrochloride does not appear to produce a toxic metabolite 
produced by other substances. For the purposes of this tolerance 
petition, therefore, it has not been assumed that propamocarb 
hydrochloride has a common mechanism of toxicity with other substances.

E. Safety Determination

    1. U.S. population. Using the conservative assumptions described 
above, based on the completeness and reliability of the toxicity data, 
it is concluded that chronic dietary exposure to the proposed uses of 
propamocarb hydrochloride will utilize at most 18% of the chronic 
reference dose for the U.S. population. The actual exposure is likely 
to be much less as more realistic data and models are developed. EPA 
generally has no concern for exposures below 100% of the RfD because 
the RfD represents the level at or below which daily aggregate exposure 
over a lifetime will not pose appreciable risk to human health. The 
acute population of concern, female 13+ utilizes 7% of the acute RfD. 
Again, this is a Tier I highly conservative assessment and actual 
exposure is likely to be far less. A very conservative ``worst-case'' 
aggregate assessment for females 13+ results in utilization of 11% of 
the RfD. DWLOCs based on the dietary and aggregate exposures are 
greater than highly conservative estimated levels, and would be 
expected to be well below the 100% level of the RfD, if they occur at 
all. Therefore, there is a reasonable certainty that no harm will occur 
to the U.S. population from aggregate exposure (food, drinking water, 
and non-dietary) to residues of propamocarb hydrochloride.
    2. Infants and children. No treatment-related effects to either 
parental animals or offspring were noted in either a 3-generation rat 
reproduction study at dose levels up to 1,000 ppm (33.3 mg/kg/day) or a 
2-generation rat reproduction study at dose levels up to 1,250 ppm (81 
mg/kg/day in males, 127 mg/kg/day in females). No evidence of 
teratogenicity was noted in either rat or rabbit developmental toxicity 
studies, even at maternally toxic dose levels. Increased post-
implantation loss was noted in the rabbit study, but only at maternally 
toxic dose levels. The NOAEL for both maternal and developmental 
toxicity in rabbits was 150 mg/kg/day.
    Decreased fetal weights, increased post-implantation loss and 
retarded ossification were noted in rats, and the developmental NOAEL 
of 221 mg/kg/day was lower than the maternal NOAEL of 740 mg/kg/day.
    FFDCA section 408 provides that the Agency may apply an additional 
safety factor for infants and children to account for prenatal and 
postnatal toxicity or incompleteness of the database. The toxicology 
database for propamocarb hydrochloride regarding potential prenatal and 
postnatal effects in children is complete according to existing Agency 
data requirements and does not indicate any particular developmental or 
reproductive concerns, therefore an additional UF to protect infants 
and children is not needed. Using the conservative assumptions 
described in the exposure section above, the percent of the chronic RfD 
that will be used for exposure to residues of propamocarb hydrochloride 
in food for children 1 to 6 (the most highly exposed sub group) is 24%. 
Infants utilize 4% of the chronic RfD. There are no chronic non-dietary 
concerns for infants and children.
    All DWLOCs are higher than the worst case DWECs and are expected to 
use well below 100% of the RfD. Therefore, there is a reasonable 
certainty that no harm will occur to infants and children from 
aggregate exposure to residues of propamocarb hydrochloride.

F. International Tolerances

    The Codex Alimentarius Commission (Codex) has established 
tolerances (maximum residue levels) for propamocarb hydrochloride in 
the following raw agricultural commodities: Beetroot at 0.2 ppm, 
brussel sprouts at 1.0 ppm, cabbage (head) at 0.1 ppm, cauliflower at 
0.2 ppm, celery at 0.2 ppm, cucumber at 2.0 ppm, lettuce (head) at 10 
ppm, pepper (sweet) at 1.0 ppm, radish at 5.0 ppm, strawberry at 0.1 
ppm and tomato at 1.0 ppm.

[FR Doc. E4-464 Filed 3-9-04; 8:45 am]
BILLING CODE 6560-50-S 

 
 


Local Navigation


Jump to main content.