PMEP Home Page --> Pesticide Active Ingredient Information --> Fungicides and Nematicides --> Acetic acid to Etridiazole --> dimethomorph (Acrobat) --> dimethomorph (Acrobat) Pesticide Tolerance 9/98

dimethomorph (Acrobat) Pesticide Tolerance 9/98

  


[Federal Register: October 13, 1998 (Volume 63, Number 197)]
[Rules and Regulations]               
[Page 54587-54594]
>From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr13oc98-15]

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

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[OPP-300740; FRL-6036-7]
RIN 2070-AB78

 
Dimethomorph [(E,Z) 4-[3-(4-chlorophenyl)-3-(3,4-
dimethoxyphenyl)-1-oxo-2-propenyl]morpholine]; Pesticide Tolerance

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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

SUMMARY: This regulation establishes a tolerance for residues of the 
fungicide dimethomorph [(E,Z) 4-[3-(4-chlorophenyl)-3-(3,4-
dimethoxyphenyl)-1-oxo-2-propenyl]morpholine] in or on potatoes. 
American Cyanamid Company requested this tolerance under the Federal 
Food, Drug and Cosmetic Act (FFDCA), as amended by the Food Quality 
Protection Act of 1996 (Pub. L. 104-170).

DATES: This regulation is effective October 13, 1998. Objections and 
requests for hearings must be received by EPA on or before December 14, 
1998.

ADDRESSES: Written objections and hearing requests, identified by the 
docket control number, [OPP-300740], must be submitted to: Hearing 
Clerk (1900), Environmental Protection Agency, Rm. M3708, 401 M St., 
SW., Washington, DC 20460. Fees accompanying objections and hearing 
requests shall be labeled ``Tolerance Petition Fees'' and forwarded to: 
EPA Headquarters Accounting Operations Branch, OPP (Tolerance Fees), 
P.O. Box 360277M, Pittsburgh, PA 15251. A copy of any objections and 
hearing requests filed with the Hearing Clerk identified by the docket 
control number, [OPP-300740], must also be submitted to: Public 
Information and Records Integrity Branch, Information Resources and 
Services Division (7502C), Office of Pesticide Programs, Environmental 
Protection Agency, 401 M St., SW., Washington, DC 20460. In person, 
bring a copy of objections and hearing requests to Rm. 119, Crystal 
Mall #2, 1921 Jefferson Davis Hwy., Arlington, VA.
    A copy of objections and hearing requests filed with the Hearing 
Clerk may also be submitted electronically by sending electronic mail 
(e-mail) to: opp-docket@epamail.epa.gov.
    Copies of objections and hearing requests must be submitted as an 
ASCII file avoiding the use of special characters and any form of 
encryption.

[[Page 54588]]

Copies of objections and hearing requests will also be accepted on 
disks in WordPerfect 5.1/6.1 file format or ASCII file format. All 
copies of objections and hearing requests in electronic form must be 
identified by the docket control number [OPP-300740]. No Confidential 
Business Information (CBI) should be submitted through e-mail. 
Electronic copies of objections and hearing requests on this rule may 
be filed online at many Federal Depository Libraries.

FOR FURTHER INFORMATION CONTACT: By mail: Mary L. Waller, Product 
Manager 21, Registration Division (7505C), Office of Pesticide 
Programs, Environmental Protection Agency, 401 M St., SW., Washington, 
DC 20460. Office location, telephone number, and e-mail address: Room 
265, Crystal Mall #2, 1921 Jefferson Davis Hwy., Arlington, VA, (703) 
308-9354, e-mail: waller.mary@epamail.epa.gov.

SUPPLEMENTARY INFORMATION: In the Federal Register of March 26, 1997 
(62 FR 14418)(FRL-5594-7), EPA issued a notice pursuant to section 408 
of the Federal Food, Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 346a(e) 
announcing the filing of a pesticide petition (PP 7F4816) for tolerance 
by American Cyanamid Company, Agricultural Products Division, P.O. Box 
400, Princeton, NJ 08543-0400. This notice included a summary of the 
petition prepared by American Cyanamid Company. There were no comments 
received in response to the notice of filing.
    The petition requested that 40 CFR 180.493 be amended by 
establishing a tolerance for residues of the fungicide dimethomorph 
[(E,Z) 4-[3-(4-chlorophenyl)-3-(3,4-dimethoxyphenyl)-1-oxo-2-
propenyl]morpholine], in or on potatoes at 0.05 parts per million 
(ppm).

I. Risk Assessment and Statutory Findings

    Section 408(b)(2)(A)(i) of the FFDCA allows EPA to establish a 
tolerance (the legal limit for a pesticide chemical residue in or on a 
food) only if EPA determines that the tolerance is ``safe.'' Section 
408(b)(2)(A)(ii) defines ``safe'' to mean that ``there is a reasonable 
certainty that no harm will result from aggregate exposure to the 
pesticide chemical residue, including all anticipated dietary exposures 
and all other exposures for which there is reliable information.'' This 
includes exposure through drinking water and in residential settings, 
but does not include occupational exposure. Section 408(b)(2)(C) 
requires EPA to give special consideration to exposure of infants and 
children to the pesticide chemical residue in establishing a tolerance 
and to ``ensure that there is a reasonable certainty that no harm will 
result to infants and children from aggregate exposure to the pesticide 
chemical residue. . . .''
    EPA performs a number of analyses to determine the risks from 
aggregate exposure to pesticide residues. For further discussion of the 
regulatory requirements of section 408 and a complete description of 
the risk assessment process, see the Final Rule on Bifenthrin Pesticide 
Tolerances (62 FR 62961, November 26, 1997) (FRL-5754-7).

II. Aggregate Risk Assessment and Determination of Safety

    Consistent with section 408(b)(2)(D), EPA has reviewed the 
available scientific data and other relevant information in support of 
this action. EPA has sufficient data to assess the hazards of 
dimethomorph and to make a determination on aggregate exposure, 
consistent with section 408(b)(2), for a tolerance for residues of 
dimethomorph on potatoes at 0.05 ppm. EPA's assessment of the dietary 
exposures and risks associated with establishing the tolerance follows.

A. Toxicological Profile

    EPA has evaluated the available toxicity data and considered its 
validity, completeness, and reliability as well as the relationship of 
the results of the studies to human risk. EPA has also considered 
available information concerning the variability of the sensitivities 
of major identifiable subgroups of consumers, including infants and 
children. The nature of the toxic effects caused by dimethomorph are 
discussed below.
    1. Acute toxicity. Technical dimethomorph is relatively non-toxic 
when administered acutely to laboratory animals (Toxicity Category III 
for Rat Acute Oral, Acute Dermal, Acute Inhalation, Primary Eye 
Irritation (conjunctival irritation clearing in 4 days); Toxicity 
Category IV for Mice Acute Oral, Z-isomer Rat Acute Oral, E-isomer Rat 
Acute Oral, Acute Dermal, Primary Eye Irritation (grade I irritation 
clearing in 48 hours), Primary Skin Irritation (grade I irritation at 
abraded skin sites only, clearing by day 2); Dermal Sensitization - not 
a sensitizer).
    2. Subchronic toxicity- i. A 90-day feeding - rat. Technical grade 
dimethomorph (98.7% a.i.) was administered in the diet to groups of 10 
male and 10 female Charles River CD Sprague-Dawley rats at 
concentrations of 0, 40, 200, or 1,000 ppm (0, 2.9, 14.2, or 73 mg/kg/
day for male rats, and 0, 3.2, 15.8, or 82 mg/kg/day for female rats, 
respectively) for 13 weeks, 4 days. A Lowest Observed Adverse Effect 
Level (LOAEL) was not established because the highest dose tested 
produced no biologically significant effects. The No Observed Adverse 
Effect Level (NOAEL) is >1,000 ppm (73 mg/kg/day for males, and 82 mg/
kg/day for females).
    ii. A 90-day feeding-dog. Dimethomorph (technical, 96.6% a.i.) was 
administered to four male and four female Beagle dogs/dose group in the 
diet at concentrations of 0, 150, 450, or 1,350 ppm (equivalent to 
doses of 0, 5, 15 or 43 mg/kg/day for males, and 0, 6, 15 or 44 mg/kg/
day for females) for 13 weeks. Prostate fibrosis occurred in all four 
of the high-dose males but not in any other male. Clinical signs were 
limited to intermittent incidences of salivation, lip-licking, tremors, 
and subdued behavior; these signs were more prevalent in the 150 and 
1,350 ppm groups but were not considered of toxicologic significance. 
The critical toxic effect appeared to be a significant decrease in the 
mean absolute and relative prostate weights of the high-dose (1,350 
ppm) male dogs relative to untreated controls. Therefore, based upon a 
decrease in the absolute and relative weights of the prostate and 
possible threshold liver effects(increased alkaline phosphatase 
activity at weeks 6 and 13), the LOAEL is 1,350 ppm (43 mg/kg/day). The 
NOAEL is 450 ppm (15 mg/kg/day).
    3. Chronic toxicity-- i. In rats. The LOAEL for systemic toxicity 
was 750 ppm (57.7 mg/kg/day) for female rats based on decreased body 
weight and significant increase in the incidence of ``ground glass'' 
foci in the liver and 2,000 ppm (99.9 mg/kg/day) for male rats based on 
decreased body weight and increased incidence of arteritis. The 
corresponding NOAEL's are 200 ppm (11.9 mg/kg/day) for females, and 750 
ppm (36.2 mg/kg/day) for males.
    ii. In dogs. At 1,350 ppm, ALK phosphatase activity was increased 
throughout the study in both sexes (245% males. 310% females). The 
LOAEL for systemic toxicity is 1,350 ppm, based on decreased prostate 
weight in males. The NOAEL was 450 ppm.
    4. Carcinogenicity-- i. In rats. The test material had no 
significant effect on the development of neoplasms in male or female 
rats at the doses tested. Dimethomorph was tested at adequate doses 
based on significant decreases in body weight (17% and 13%) and body 
weight gains (27% and 14%) in females and males, respectively, in the 
high dose groups. The LOAEL for systemic

[[Page 54589]]

toxicity was 2,000 ppm in males and 750 ppm in females. The NOAEL's 
were 750 ppm (33.9 mg/kg/day) for males and 200 ppm (11.3 mg/kg/day) 
for females.
    ii. In mice. There were no treatment related increases in the 
incidence of any neoplastic lesions. The chemical was adequately tested 
based on decreased body weight gain (17% and 22% less than control in 
males and females, respectively, at 1,000 mg/kg/day). The NOAEL for 
systemic toxicity was 100 mg/kg/day.
    5. Developmental toxicity-- i. In rats. Maternal LOAEL = 160 mg/kg/
day, based on decreased mean body weight on gestation days 10-15; 
decreased body weight gain on gestation days 10-15, decreased food 
consumption days 6-15; Maternal NOAEL = 60 mg/kg/day; Developmental 
LOAEL = 160 mg/kg/day based on increased resorptions; Developmental 
NOAEL = 60 mg/kg/ day.
    ii. In rabbits. Maternal LOAEL = 650 mg/kg/day, based on decreased 
body weights and body weight gain. Maternal NOAEL = 300 mg/kg/day. No 
developmental toxicity was observed in this study. Developmental NOAEL 
= 650 mg/kg/day.
    6. Two-generation reproduction study in rats. Parental toxicity 
LOAEL = 1,000 ppm, based on decreased body weights and body weight 
gain; Parental NOAEL = 300 ppm (20.8 mg/kg/day for males; 24 mg/kg/day 
for females); Developmental Toxicity LOAEL = 1,000 ppm based on delayed 
incisor eruption at day 10 postpartum; Developmental Toxicity NOAEL = 
300 ppm; Reproductive Toxicity NOAEL = 1,000 ppm (69 mg/kg/day for 
males; 79.3 mg/kg/day for females).
    7. Mutagenicity. The studies indicate that dimethomorph did not 
cause gene mutations in Salmonella or E. Coli bacterial strains, as 
well as in mammalian gene mutation studies. It was negative for 
structural chromosomal aberrations in the mouse micronucleus assay at 
up to 5,000 mg/kg after oral treatment, and up to 200 mg/kg when 
administered i.p. However, dimethomorph gave positive responses when 
tested in CH lung and in human lymphocytes. It was negative in the cell 
transformation assay in Syrian hamster embryo cells with and without 
activation at up to cytotoxic levels.
    8. Dermal penetration. Radio-labeled <SUP>14</SUP>C-dimethomorph 
(97.6%; labeled in the chlorophenyl ring) was administered dermally to 
4 male SD rats/group in water for 8 hours at doses of 7.73 (2.5% w/v 
aqueous suspension) or 79.62(25% w/v aqueous suspension)mg/kg. Dermal 
absorption was 0.05%, 0.07% and 0.27% of the administered dose from 
rats 4, 8, and 24 hours after dermal treatment at 7.73 mg/kg, and 
0.02%, 0.16% and 0.12% of the dose at 79.62 mg/kg. Six days after 
treatment the percent total absorption of the dose in the 7.73 and 
79.62 mg/kg was 4.76 and 1.20 percent respectively. Mean percent 
recovery of the <SUP>14</SUP>C for dose levels of 7.73 and 79.62 mg/kg 
was 104.1% and 92.1%, respectively.
    9. Neurotoxicity. There are no acute, subchronic, or developmental 
neurotoxicity studies available in the data base for dimethomorph. 
However, in none of the subchronic, chronic, developmental, or 
reproduction studies was there any indication that the nervous system 
was affected by administration of dimethomorph. No evidence of 
neurotoxicity was observed in the available data base.
    10. General metabolism. Rat Oral administration of dimethomorph (10 
mg/kg single dose; 10 mg/kg 14-day repeated dose; 10 mg/kg 7-day 
repeated dose; 500 mg/kg single dose) results in rapid excretion into 
the urine and feces of rats. For all treatment protocols, most (80-90%) 
of the radiolabel administered was excreted in the feces. A 
considerably smaller amount (6-16%) was excreted in the urine and only 
minimal levels (0.1-0.4%) were detected in the organs and tissues. 
Rapid absorption may be inferred by the rapid excretion of metabolites 
in the urine and bile. Saturation of absorption following single high 
doses (500 mg/kg) was indicated by large amounts (<nearly-eq>50%) of 
radioactivity in the feces being associated with parent compound. For 
low- or high-dose treatment, urinary excretion in female rats tended to 
be greater (up to 2-fold in low-dose rats) than that of male rats. 
Retention of dimethomorph or <SUP>14</SUP>C-dimethomorph-derived 
radioactivity was generally <ls-thn-eq> 1% for most tissues although 
the liver exhibited slightly higher levels (1.4%) and higher levels in 
the gastrointestinal tract organswas due to radioactivity in the 
lumenal contents. Urinary metabolites resulted from demethylation of 
the dimethoxyphenyl ring and oxidation of the morpholine ring. Biliary 
excretion exhibited first-order kinetics with a low-dose (10 mg/kg) 
half-life of approximately 3 hours and a high-dose (500 mg/kg) half-
life of 11 hours for males and about 6 hours for females. Biliary 
metabolites accounted for most of the fecal excretion following low-
dose treatment. The major biliary metabolites were glucuronides of one 
and possibly two of the compounds produced by demethylation of the 
dimethoxyphenyl ring. The report provided a proposed metabolic pathway 
for dimethomorph.

B. Toxicological Endpoints

    1. Acute toxicity. EPA did not select a dose and endpoint for an 
acute dietary risk assessment due to the lack of toxicological effects 
attributable to a single exposure (dose) in either the rat or the 
rabbit developmental toxicity studies. Therefore an acute RfD was not 
calculated.
    2.  Short- and intermediate-term toxicity. EPA established NOAELs 
of 60 mg/kg/day and 15 mg/kg/day to be used in risk assessments for 
workers for short- and intermediate-term dermal and inhalation 
exposures, respectively. The NOAEL for short-term exposure is based on 
the maternal NOAEL established in the rat developmental toxicity study 
and the NOAEL for intermediate-term exposure is based on the NOAEL 
established in the 90-day dog feeding study. As the exposures are by 
dermal and inhalation routes and these are oral studies, a dermal 
absorption factor of 5 percent, derived from the dermal absorption 
study, is included in the risk assessment. Inhalation absorption is 
assumed to be 100%.
    3. Chronic toxicity. EPA selected a NOAEL of 11 mg/kg/day 
established in the chronic oncogenicity feeding study in the rat. This 
NOAEL was nearly identical to that established in the rat chronic 
feeding study. The LOAEL was 46.3 mg/kg/day based on decreased body 
weight and liver lesions in female rats. A 100 fold safety factor was 
applied (10 for inter-species extrapolation, and 10 for intra-species 
variation). Thus, the chronic RfD was calculated to be 0.1 mg/kg/day. 
The EPA FQPA Safety Factor Committee determined that, for chronic 
dietary risk assessment, the 10x factor to account for enhanced 
sensitivity to infants and children (as required by FQPA) should be 
removed. Neither a chronic dermal nor inhalation endpoint were 
identified as the current use pattern does not indicate a concern for 
long term exposure.
    4. Carcinogenicity. There was no increased incidence of neoplasms 
in the rat chronic or carcinogenicity studies or in the mouse 
carcinogenicity study. EPA determined that the chemical had been tested 
at adequate dosage in the rat study, as demonstrated by the high 
incidence of arteritis in males, and the pronounced decrease in body 
weight in females at the mid- and high-dose levels. EPA also determined 
that the high dose tested (1,000 mg/kg/day) in the mouse study was the 
maximum dose required by the test guidelines for a dietary oncogenicity 
study. Therefore,

[[Page 54590]]

EPA classified dimethomorph as ``not likely'' to be a human carcinogen.

C. Exposures and Risks

    1. From food and feed uses. Time-limited tolerances are established 
for residues of dimethomorph in or on cantaloupes, cucumbers, tomatoes, 
squash and watermelons at 1.0 ppm, potatoes at 0.05 ppm, tomato paste 
at 6.0 ppm and tomato puree at 2.0 ppm in connection with use of the 
pesticide under section 18 emergency exemptions granted by EPA. Risk 
assessments were conducted by EPA to assess dietary exposures from 
dimethomorph as follows:
    i.  Acute exposure and risk. Acute dietary risk assessments are 
performed for a food-use pesticide if a toxicological study has 
indicated the possibility of an effect of concern occurring as a result 
of a one day or single exposure. An acute dietary exposure assessment 
is not required because no acute toxicological effects endpoints were 
identified for dimethomorph due to the lack of toxicological effects 
attributable to a single exposure (dose) in either the rat or the 
rabbit developmental toxicity studies.
    ii. Chronic exposure and risk. EPA's Dietary Exposure Evaluation 
Model (DEEM89) was used for conducting a chronic dietary (food only) 
exposure analysis (risk assessment). The analysis evaluates individual 
food consumption, as reported by respondents in the USDA 1989-1992 
Nationwide Food Consumption Survey, and accumulates exposure to the 
chemical for each commodity. In conducting this chronic dietary (food) 
risk assessment, EPA made very conservative assumptions: that all 
commodities having dimethomorph tolerances will contain residues of 
dimethomorph and those residues will be at the level of the tolerance. 
These assumptions result in an overestimate of human dietary exposure. 
All section 18 tolerances (cantaloupes, watermelons, cucumbers, squash, 
tomatoes) are included in this dietary risk assessment.
    Using the assumptions and data parameters described above, the 
DEEM89 exposure analysis results in a theoretical maximum residue 
contribution (TMRC) (exposure) that is equivalent to the following 
percentages of the chronic RfD:

------------------------------------------------------------------------
                                          TMRC <INF>food (mg/kg/
           Population Subgroup                   day)        Percent RfD
------------------------------------------------------------------------
U.S. Population (48 states).............             0.0018          1.8
Nursing Infants (<1 year old)...........            0.00054          0.5
Non-Nursing Infants (<1 year old).......             0.0021          2.1
Children (1-6 years old)................             0.0039          3.9
Children (7-12 years old)...............             0.0027          2.7
Females (13-19 yrs/not preg. or nursing)             0.0020          2.0
Males (13-19 years).....................             0.0019          1.9
U.S. Population - Summer Season.........             0.0021          2.1
Northeast Region........................             0.0021          2.1
Hispanics...............................             0.0020          2.0
Non-Hispanic other than black or white..             0.0021          2.1
------------------------------------------------------------------------

    EPA does not consider the chronic dietary risk to exceed the 
Agency's level of concern.
    2. From drinking water. There is no established Maximum Contaminant 
Level for dimethomorph in drinking water. No health advisory levels 
have been established for residues of dimethomorph in drinking water. 
The predicted dimethomorph surface and ground water concentrations are 
well below EPA's drinking water level of concern (DWLOC). EPA used the 
SCI-GROW (Screening Concentration In Ground Water) Model to estimate 
the Estimated Environmental Concentration (EEC) of dimethomorph 
residues in ground water. The reported EEC for dimethomorph residues 
using SCI-GROW is 0.26 ppb. EPA used GENEEC (Generic Estimated 
Environmental Concentration) Model to estimate acute and chronic EECs 
of dimethomorph residues in surface water. The GENEEC model estimated 
that, with the present use pattern, surface water concentrations of 
dimethomorph ranged from a peak of 28 ppb to a 56 day concentration of 
24 ppb. EPA's level of concern for chronic exposure to residues of 
dimethomorph range from 960 ppb for children 1-6 years old to 3,400 ppb 
for the U.S. population and males 13 years and older. Therefore, 
exposure from water is below EPA's level of concern for all of the 
populations examined.
    i. Acute exposure and risk. Because no acute dietary endpoint was 
determined, an acute water and dietary exposure risk assessment is not 
required.
    ii. Chronic exposure and risk. EPA conducts the drinking water risk 
assessment by using the worst case scenario of EEC found from either 
ground or surface water. The EEC reported for dimethomorph residues in 
ground water using SCI-GROW is 0.26 ppb. This is much less than the 
surface water EECs (24.4 ppb for 56-days) generated using GENEEC. 
Therefore, only the surface water EECs were used in conducting the 
aggregate dietary (food + water) risk assessment. Based on the chronic 
dietary (food) exposure and using default body weights and water 
consumption figures, chronic drinking water levels of concern (DWLOC) 
for drinking water were calculated. To calculate the chronic DWLOC, the 
chronic dietary food exposure (from DEEM analysis) was subtracted from 
the chronic RfD. DWLOCs were then calculated using the default body 
weights and drinking water consumption figures. EPA's surface drinking 
water levels of concern from chronic exposure to dimethomorph using 
modeling data are 3,400 ppb for the U.S. Population and males 13 years 
and older, 2,900 ppb for females 13 years and older, and 960 ppb for 
children (1-6 years of age). These levels are all greater than the 
GENEEC concentration level (24.4 ppm for 56-days). Therefore, EPA does 
not expect exposure to dimethomorph in drinking water to be above our 
level of concern.
    3. From non-dietary exposure. There are no registered or proposed 
residential uses for dimethomorph. Therefore, residential or inhalation 
exposures were not evaluated in the risk assessment. A risk assessment 
was evaluated for occupational risk to workers who could be exposed to 
dimethomorph through simultaneous dermal and inhalation exposure. 
Agricultural workers evaluated in this analysis include: ground mixer/
loaders, ground applicators, aerial mixer/loaders and aerial 
applicators. The dermal and inhalation short-term margin of exposure 
(MOE) ranged from 1,200 for aerial mixer/loaders using the wettable

[[Page 54591]]

powder (WP) to 190,000 for aerial applicators. The intermediate-term 
MOEs range from 290 for aerial mixer/loaders using WP to 47,000 for 
aerial applicators. Exposure from post-application of dimethomorph 
resulted in MOEs ranging from 23,000 for short-term to 5,800 for 
intermediate-term. None of these MOEs exceed HED's level of concern 
(i.e., acceptable MOE > 100) for occupationally exposed workers. 
Therefore, these workers are unlikely to experience adverse health 
effects under the conditions evaluated.
    4. Cumulative exposure to substances with common mechanism of 
toxicity. Section 408(b)(2)(D)(v) requires that, when considering 
whether to establish, modify, or revoke a tolerance, the Agency 
consider ``available information'' concerning the cumulative effects of 
a particular pesticide's residues and ``other substances that have a 
common mechanism of toxicity.''
    EPA does not have, at this time, available data to determine 
whether dimethomorph 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, 
dimethomorph does not appear to produce a toxic metabolite produced by 
other substances. For the purposes of this tolerance action, therefore, 
EPA has not assumed that dimethomorph has a common mechanism of 
toxicity with other substances. For information regarding EPA's efforts 
to determine which chemicals have a common mechanism of toxicity and to 
evaluate the cumulative effects of such chemicals, see the Final Rule 
for Bifenthrin Pesticide Tolerances (62 FR 62961, November 26, 1997).

D. Aggregate Risks and Determination of Safety for U.S. Population

    1. Acute risk. An acute aggregate risk assessment is not required 
because no acute dietary endpoint was determined.
    2. Chronic risk. EPA concludes that the chronic exposure to 
dimethomorph from food will utilize 1.8% of the RfD for the U.S. 
population, 2.0% for females (13+ not pregnant or nursing), 1.9% for 
males 13 years and older, and 3.9% for children ages 1 through 6 years 
of age. The surface drinking water levels of concern from chronic 
exposure to dimethomorph using modeling data are 3,400 ppb for the U.S. 
Population and males 13 years and older, 2,900 ppb for females 13 years 
and older and 960 ppb for children (1-6 years of age). These levels are 
all greater than the GENEEC chronic concentration level (24.4 ppb for 
56 days) and the SCI-GROW ground water level of 0.26 ppb. There are no 
registered residential uses of dimethomorph. 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. Despite the 
potential for exposure to dimethomorph in drinking water, EPA does not 
expect the aggregate exposure to exceed 100% of the RfD. Therefore, EPA 
concludes that there is reasonable certainty that no harm will result 
to either adults or children from chronic aggregate exposure to 
dimethomorph residues.
    3. Short- and intermediate-term risk. Short- and intermediate-term 
aggregate exposure takes into account chronic dietary food and water 
(considered to be a background exposure level) plus indoor and outdoor 
residential exposure. Although short- and intermediate-term endpoints 
were identified, there are no residential uses for dimethomorph. 
Therefore, an aggregate risk assessment is not required for short- and 
intermediate-term endpoints.
    4. Aggregate cancer risk for U.S. population. Dimethomorph was 
classified as ``not likely'' to be a human carcinogen). Therefore, a 
carcinogenic aggregate risk assessment is not required.
    5. Determination of safety. Based on these risk assessments, EPA 
concludes that there is a reasonable certainty that no harm will result 
from aggregate exposure to dimethomorph residues.

E. Aggregate Risks and Determination of Safety for Infants and Children

    1. Safety factor for infants and children-- i. In general. In 
assessing the potential for additional sensitivity of infants and 
children to residues of dimethomorph, EPA considered data from 
developmental toxicity studies in the rat and rabbit and a two-
generation reproduction study in the rat. The developmental toxicity 
studies are designed to evaluate adverse effects on the developing 
organism resulting from maternal pesticide exposure during gestation. 
Reproduction studies provide information relating to effects from 
exposure to the pesticide on the reproductive capability of mating 
animals and data on systemic toxicity. The toxicology data on 
dimethomorph provides no indication of enhanced sensitivity of infants 
and children based on the results from developmental studies conducted 
with rats and rabbits as well as a two-generation reproduction study 
conducted with rats. In neither the rat developmental toxicity study 
nor in the 2-generation study were any toxic effects observed at doses 
lower than in the parents. No developmental toxicity was demonstrated 
in the rabbit developmental toxicity study.
    FFDCA of section 408 provides that EPA shall apply an additional 
tenfold margin of safety for infants and children in the case of 
threshold effects to account for pre-and post-natal toxicity and the 
completeness of the database unless EPA determines that a different 
margin of safety will be safe for infants and children. Margins of 
safety are incorporated into EPA risk assessments either directly 
through use of a margin of exposure (MOE) analysis or through using 
uncertainty (safety) factors in calculating a dose level that poses no 
appreciable risk to humans. EPA believes that reliable data support 
using the standard uncertainty factor (usually 100 for combined inter- 
and intra-species variability)) and not the additional tenfold MOE/
uncertainty factor when EPA has a complete data base under existing 
guidelines and when the severity of the effect in infants or children 
or the potency or unusual toxic properties of a compound do not raise 
concerns regarding the adequacy of the standard MOE/safety factor.
    ii. Pre- and post-natal sensitivity. The data provided no evidence 
of special sensitivity of rats or rabbits to in utero and/or postnatal 
exposure to dimethomorph. In the prenatal developmental study in rats, 
an increased incidence of post implantation loss, considered by EPA to 
be minimal, was observed in the presence of maternal toxicity. In the 
developmental toxicity in rabbits, no evidence of developmental 
toxicity was seen, even at the highest dose tested. In the two-
generation study in rats, effects in the offspring were observed only 
at dose levels that produced parental toxicity. There is no evidence 
that dimethomorph is a neurotoxic chemical. EPA determined that the 10x 
factor to account for enhanced sensitivity of infants and children be 
removed.
    iii. Conclusion. There is a complete toxicity database for 
dimethomorph and exposure data is complete or is estimated based on 
data that reasonably accounts for potential exposures.
    2. Acute risk. An acute aggregate risk assessment is not required 
because no acute dietary endpoints were identified for dimethomorph.
    3. Chronic risk. Using the exposure assumptions described above, 
EPA has concluded that aggregate exposure to dimethomorph from food 
will utilize 4% of the RfD for infants and children.

[[Page 54592]]

 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. Despite the potential for exposure to dimethomorph in 
drinking water, EPA does not expect the aggregate exposure to exceed 
100% of the RfD.
    4. Short- or intermediate-term risk. Although short- and 
intermediate-term endpoints were identified, there are no residential 
uses for dimethomorph. Therefore, an aggregate risk assessment is not 
required for short- and intermediate-term endpoints.
    5. Determination of safety. Based on these risk assessments, EPA 
concludes that there is a reasonable certainty that no harm will result 
to infants and children from aggregate exposure to dimethomorph 
residues.

III. Other Considerations

A. Metabolism In Plants and Animals

    The nature of the residue in plants and in animals are adequately 
understood. The major residue of regulatory concern is the parent 
dimethomorph compound. Tolerances on animal commodities are not 
required in conjunction with this use. There is no need for additional 
poultry metabolism data at this time since no uses are pending on 
poultry feed items.

B. Analytical Enforcement Methodology

    An adequate method is available for enforcement of the proposed 
tolerances. Method FAMS 002-04 (High Performance Liquid Chromatography 
(HPLC), Ultraviolet (UV) detection) is adequate for determining 
residues of dimethomorph per se in/on potatoes. A confirmatory method 
is also available (FAM 022-03).
    The method may be requested from: Calvin Furlow, PIRIB, IRSD 
(7502C), Office of Pesticide Programs, Environmental Protection Agency, 
401 M St., SW., Washington, DC 20460. Office location and telephone 
number: Rm 101FF, Crystal Mall #2, 1921 Jefferson Davis Hwy., 
Arlington, VA 22202, (703-305-5229).

C. Magnitude of Residues

    EPA has concluded that residue data submitted in support of the 
tolerance for imported potatoes indicate that a tolerance level of 0.05 
ppm is an adequate level for domestic potatoes. In addition, domestic 
field trial data supported the tolerance level of 0.05 ppm on potatoes 
and indicated that dimethomorph residues do not pose an adverse health 
risk to humans under the use conditions. Therefore, EPA has no 
objection to the establishment of a tolerance of 0.05 ppm for residues 
of the fungicide dimethomorph in/on potatoes under 40 CFR 180.493.

D. International Residue Limits

    There are no Canadian, Mexican, or Codex MRLs established for 
dimethomorph for the commodities associated with this request: 
consequently, a discussion of international harmonization is not 
relevant.

E. Rotational Crop Restrictions

    EPA concluded it is permissible to rotate to leafy vegetables and 
root crops after a 120-day plant back interval. Rotation to potatoes 
will be permitted at any time. For crops other than potatoes, leafy 
vegetables, and root crops, a 1-year plant back interval will be 
required.

IV. Conclusion

    Therefore, the tolerance is established for residues of 
dimethomorph [(E,Z) 4-[3-(4-chlorophenyl)-3-(3,4-dimethoxyphenyl)-1-
oxo-2-propenyl]morpholine] in potatoes at 0.05 ppm.

V. Objections and Hearing Requests

    The new FFDCA section 408(g) provides essentially the same process 
for persons to ``object'' to a tolerance regulation issued by EPA under 
new section 408(e) and (l)(6) as was provided in the old section 408 
and in section 409. However, the period for filing objections is 60 
days, rather than 30 days. EPA currently has procedural regulations 
which govern the submission of objections and hearing requests. These 
regulations will require some modification to reflect the new law. 
However, until those modifications can be made, EPA will continue to 
use those procedural regulations with appropriate adjustments to 
reflect the new law.
    Any person may, by December 14, 1998, file written objections to 
any aspect of this regulation and may also request a hearing on those 
objections. Objections and hearing requests must be filed with the 
Hearing Clerk, at the address given above (40 CFR 178.20). A copy of 
the objections and/or hearing requests filed with the Hearing Clerk 
should be submitted to the OPP docket for this rulemaking. The 
objections submitted must specify the provisions of the regulation 
deemed objectionable and the grounds for the objections (40 CFR 
178.25). Each objection must be accompanied by the fee prescribed by 40 
CFR 180.33(i). If a hearing is requested, the objections must include a 
statement of the factual issues on which a hearing is requested, the 
requestor's contentions on such issues, and a summary of any evidence 
relied upon by the requestor (40 CFR 178.27). A request for a hearing 
will be granted if the Administrator determines that the material 
submitted shows the following: There is genuine and substantial issue 
of fact; there is a reasonable possibility that available evidence 
identified by the requestor would, if established, resolve one or more 
of such issues in favor of the requestor, taking into account 
uncontested claims or facts to the contrary; and resolution of the 
factual issues in the manner sought by the requestor would be adequate 
to justify the action requested (40 CFR 178.32). Information submitted 
in connection with an objection or hearing request may be claimed 
confidential by marking any part or all of that information as CBI. 
Information so marked will not be disclosed except in accordance with 
procedures set forth in 40 CFR part 2. A copy of the information that 
does not contain CBI must be submitted for inclusion in the public 
record. Information not marked confidential may be disclosed publicly 
by EPA without prior notice.

VI. Public Record and Electronic Submissions

    EPA has established a record for this rulemaking under docket 
control number [OPP-300740] (including any comments and data submitted 
electronically). A public version of this record, including printed, 
paper versions of electronic comments, which does not include any 
information claimed as CBI, is available for inspection from 8:30 a.m. 
to 4 p.m., Monday through Friday, excluding legal holidays. The public 
record is located in Room 119 of the Public Information and Records 
Integrity Branch, Information Resources and Services Division (7502C), 
Office of Pesticide Programs, Environmental Protection Agency, Crystal 
Mall #2, 1921 Jefferson Davis Hwy., Arlington, VA.
    Electronic comments may be sent directly to EPA at:
    opp-docket@epamail.epa.gov.


    Electronic comments must be submitted as an ASCII file avoiding the 
use of special characters and any form of encryption.
    The official record for this rulemaking, as well as the public 
version, as described above will be kept in paper form. Accordingly, 
EPA will transfer any copies of objections and hearing requests 
received electronically into printed, paper form as they are

[[Page 54593]]

received and will place the paper copies in the official rulemaking 
record which will also include all comments submitted directly in 
writing. The official rulemaking record is the paper record maintained 
at the Virginia address in ``ADDRESSES'' at the beginning of this 
document.

VII. Regulatory Assessment Requirements

A. Certain Acts and Executive Orders

    This final rule establishes a tolerance under FFDCA section 408(d) 
in response to a petition submitted to the Agency. The Office of 
Management and Budget (OMB) has exempted these types of actions from 
review under Executive Order 12866, entitled Regulatory Planning and 
Review (58 FR 51735, October 4, 1993). This final rule does not contain 
any information collections subject to OMB approval under the Paperwork 
Reduction Act (PRA), 44 U.S.C. 3501 et seq., or impose any enforceable 
duty or contain any unfunded mandate as described under Title II of the 
Unfunded Mandates Reform Act of 1995 (UMRA) (Pub. L. 104-4). Nor does 
it require any prior consultation as specified by Executive Order 
12875, entitled Enhancing the Intergovernmental Partnership (58 FR 
58093, October 28, 1993), or special considerations as required by 
Executive Order 12898, entitled Federal Actions to Address 
Environmental Justice in Minority Populations and Low-Income 
Populations (59 FR 7629, February 16, 1994), or require OMB review in 
accordance with Executive Order 13045, entitled Protection of Children 
from Environmental Health Risks and Safety Risks (62 FR 19885, April 
23, 1997).
    In addition, since tolerances and exemptions that are established 
on the basis of a petition under FFDCA section 408(d), such as the 
tolerance in this final rule, do not require the issuance of a proposed 
rule, the requirements of the Regulatory Flexibility Act (RFA) (5 
U.S.C. 601 et seq.) do not apply. Nevertheless, the Agency has 
previously assessed whether establishing tolerances, exemptions from 
tolerances, raising tolerance levels or expanding exemptions might 
adversely impact small entities and concluded, as a generic matter, 
that there is no adverse economic impact. The factual basis for the 
Agency's generic certification for tolerance actions published on May 
4, 1981 (46 FR 24950) and was provided to the Chief Counsel for 
Advocacy of the Small Business Administration.

B. Executive Order 12875

    Under Executive Order 12875, entitled Enhancing the 
Intergovernmental Partnership (58 FR 58093, October 28, 1993), EPA may 
not issue a regulation that is not required by statute and that creates 
a mandate upon a State, local, or tribal government, unless the Federal 
government provides the funds necessary to pay the direct compliance 
costs incurred by those governments. If the mandate is unfunded, EPA 
must provide to OMB a description of the extent of EPA's prior 
consultation with representatives of affected State, local, and tribal 
governments, the nature of their concerns, copies of any written 
communications from the governments, and a statement supporting the 
need to issue the regulation. In addition, Executive Order 12875 
requires EPA to develop an effective process permitting elected 
officials and other representatives of State, local, and tribal 
governments ``to provide meaningful and timely input in the development 
of regulatory proposals containing significant unfunded mandates.''
    Today's rule does not create an unfunded Federal mandate on State, 
local, or tribal governments. The rule does not impose any enforceable 
duties on these entities. Accordingly, the requirements of section 1(a) 
of Executive Order 12875 do not apply to this rule.

C. Executive Order 13084

    Under Executive Order 13084, entitled Consultation and Coordination 
with Indian Tribal Governments (63 FR 27655, May 19,1998), EPA may not 
issue a regulation that is not required by statute, that significantly 
or uniquely affects the communities of Indian tribal governments, and 
that imposes substantial direct compliance costs on those communities, 
unless the Federal government provides the funds necessary to pay the 
direct compliance costs incurred by the tribal governments. If the 
mandate is unfunded, EPA must provide to OMB, in a separately 
identified section of the preamble to the rule, a description of the 
extent of EPA's prior consultation with representatives of affected 
tribal governments, a summary of the nature of their concerns, and a 
statement supporting the need to issue the regulation. In addition, 
Executive Order 13084 requires EPA to develop an effective process 
permitting elected officials and other representatives of Indian tribal 
governments ``to provide meaningful and timely input in the development 
of regulatory policies on matters that significantly or uniquely affect 
their communities.''
    Today's rule does not significantly or uniquely affect the 
communities of Indian tribal governments. This action does not involve 
or impose any requirements that affect Indian tribes. Accordingly, the 
requirements of section 3(b) of Executive Order 13084 do not apply to 
this rule.

VIII. Submission to Congress and the Comptroller General

    The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the 
Small Business Regulatory Enforcement Fairness Act of 1996, generally 
provides that before a rule may take effect, the agency promulgating 
the rule must submit a rule report, which includes a copy of the rule, 
to each House of the Congress and to the Comptroller General of the 
United States. EPA will submit a report containing this rule and other 
required information to the U.S. Senate, the U.S. House of 
Representatives, and the Comptroller General of the United States prior 
to publication of the rule in the Federal Register. This rule is not a 
``major rule'' as defined by 5 U.S.C. 804(2).

List of Subjects in 40 CFR Part 180

    Environmental protection, Administrative practice and procedure, 
Agricultural commodities, Pesticides and pests, Reporting and 
recordkeeping requirements.

    Dated: September 30, 1998.

Marcia E. Mulkey,

Director, Office of Pesticide Programs.
    Therefore, 40 CFR chapter I is amended as follows:

PART 180--[AMENDED]

    1. The authority citation for part 180 continues to read as 
follows:

    Authority: 21 U.S.C. 346a and 371.

    2. In section 180.493, by revising paragraph (a) to read as 
follows:


Sec. 180.493   Dimethomorph [(E,Z) 4-[3-(4-chlorophenyl)-3-(3,4-
dimethoxyphenyl)-1-oxo-2-propenyl]morpholine]; tolerances for residues.

    (a) General. A tolerance is established for the residues of the 
fungicide dimethomorph [(E,Z) 4-[3-(4-chlorophenyl)-3-(3,4-
dimethoxyphenyl)-1-oxo-2-propenyl]morpholine] in or on the following 
commodity:

------------------------------------------------------------------------
                 Commodity                        Parts per million
------------------------------------------------------------------------
Potatoes..................................  0.05
------------------------------------------------------------------------


[[Page 54594]]

*    *    *    *    *

[FR Doc. 98-27396 Filed 10-9-98; 8:45 am]
BILLING CODE 6560-50-F