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Notice

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

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Information about this document as published in the Federal Register.

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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 control number PF-1043, must be received on or before October 22, 2001.

ADDRESSES:

Comments may be submitted by mail, electronically, or in person. Please follow the detailed instructions for each method as provided in Unit I.C. of the SUPPLEMENTARY INFORMATION. To ensure proper receipt by EPA, it is imperative that you identify docket control number PF-1043 in the subject line on the first page of your response.

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FOR FURTHER INFORMATION CONTACT:

By mail: Driss Benmhend, Biopesticides and Pollution Prevention Division (7511C), Office of Pesticide Programs, Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460; telephone number: (703) 308-9525; e-mail address: benmhend.driss@epa.gov.

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SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this Action Apply to Me?

You may be affected by this action if you are an agricultural producer, food manufacturer or pesticide manufacturer. Potentially affected categories and entities may include, but are not limited to:

CategoriesNAICS codesExamples of potentially affected entities
Industry111Crop production
112Animal production
311Food manufacturing
32532Pesticide manufacturing

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 the table could also be affected. The North American Industrial Classification System (NAICS) codes have been provided to assist you and others in determining whether or not this action might apply to certain entities. If you have 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 Additional Information, Including Copies of this Document and Other Related Documents?

1. Electronically. You may obtain electronic copies of this document, and certain other related documents that might be available electronically, from the EPA Internet Home Page at http://www.epa.gov/​. To access this document, on the Home Page select “Laws and Regulations,” “Regulations and Proposed Rules,” and then look up the entry for this document under the “Federal Register—Environmental Documents.” You can also go directly to the Federal Register listings at http://www.epa.gov/​fedrgstr/​.

2. In person. The Agency has established an official record for this action under docket control number PF-1043. The official record consists of the documents specifically referenced in this action, any public comments received during an applicable comment period, and other information related to this action, including any information claimed as confidential business information (CBI). This official record includes the documents that are physically located in the docket, as well as the documents that are referenced in those documents. The public version of the official record does not include any information claimed as CBI. The public version of the official record, which includes printed, paper versions of any electronic comments submitted during an applicable comment period, is available for inspection in the Public Information and Records Integrity Branch (PIRIB), Rm. 119, Crystal Mall #2, 1921 Jefferson Davis Highway, Arlington, VA, from 8:30 a.m. to 4 p.m., Start Printed Page 48678Monday through Friday, excluding legal holidays. The PIRIB telephone number is (703) 305-5805.

C. How and to Whom Do I Submit Comments?

You may submit comments through the mail, in person, or electronically. To ensure proper receipt by EPA, it is imperative that you identify docket control number PF-1043 in the subject line on the first page of your response.

1. By mail. Submit your comments to: Public Information and Records Integrity Branch (PIRIB), Information Resources and Services Division (7502C), Office of Pesticide Programs (OPP), Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460.

2. In person or by courier. Deliver your comments to: Public Information and Records Integrity Branch (PIRIB), Information Resources and Services Division (7502C), Office of Pesticide Programs (OPP), Environmental Protection Agency, Rm. 119, Crystal Mall #2, 1921 Jefferson Davis Highway, Arlington, VA. The PIRIB is open from 8:30 a.m. to 4 p.m., Monday through Friday, excluding legal holidays. The PIRIB telephone number is (703) 305-5805.

3. Electronically. You may submit your comments electronically by e-mail to: opp-docket@epa.gov, or you can submit a computer disk as described above. Do not submit any information electronically that you consider to be CBI. Avoid the use of special characters and any form of encryption. Electronic submissions will be accepted in Wordperfect 6.1/8.0 or ASCII file format. All comments in electronic form must be identified by docket control number PF-1043. Electronic comments may also be filed online at many Federal Depository Libraries.

D. How Should I Handle CBI That I Want to Submit to the Agency?

Do not submit any information electronically that you consider to be CBI. You may claim information that you submit to EPA in response to this document as CBI 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. 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 version of the official record. Information not marked confidential will be included in the public version of the official record without prior notice. If you have any questions about CBI or the procedures for claiming CBI, please consult the person identified 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 control 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 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.

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List of Subjects

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Dated: September 7, 2001.

Janet L. Andersen,

Director, Biopesticides and Pollution Prevention Division, Office of Pesticide Programs.

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Summary of Petition

The petitioner's summary of the pesticide petition is printed below as required by section 408(d)(3) of the FFDCA. 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.

Platte Chemical Company Petition Summary

PP 1F6338

EPA has received a pesticide petition [PP 1F6338] from Platte Chemical Company, 419 18th Street, Greely, CO 80632, proposing pursuant to section 408(d) of the FFDCA, 21 U.S.C. 346a(d), to amend 40 CFR part 180, to establish an exemption from the requirement of a tolerance for the biochemical pesticide 2,6-diisopropylnaphthalene (2,6-DIPN) in or on raw agricultural commodities.

Pursuant to section 408(d)(2)(A)(i) of the FFDCA, as amended, Platte Chemical Company has submitted the following summary of information, data, and arguments in support of their pesticide petition. This summary was prepared by Platte Chemical Company and EPA has not fully evaluated the merits of the pesticide petition. The summary may have been edited by EPA if the terminology used was unclear, the summary contained extraneous material, or the summary unintentionally made the reader conclude that the findings reflected EPA's position and not the position of the petitioner.

In the Federal Register of September 22, 1999 (64 FR 51245) (FRL-6381-7), EPA issued a rule pursuant to section 408 of the Federal Food, Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 346a, as amended by the Food Quality Protection Act (FQPA) (Public Law 104-170) establishing a temporary exemption from the requirement of a tolerance for residues of 2,6-DIPN. This request for temporary exemption from the requirement of a tolerance was associated with an experimental use permit (EUP) (EUP No. 34704 EUP-13). At this time, Platte Chemical Company is seeking a full registration of 2,6-DIPN as a potato sprout inhibitor and is petitioning for a tolerance exemption.

A. Product Name and Proposed Use Practices

2,6-Diisopropylnaphthalene (2,6-DIPN) will be applied at a rate of 1 pound active ingredient per 600 cwt (1 cut weight equals approximately 100 pounds) of potatoes. All applications to Start Printed Page 48679potatoes will be made indoors in potato storage facilities.

B. Product Identity/Chemistry

1. Identity of the pesticide and corresponding residues. 2,6-Diisopropylnaphthalene (2,6-DIPN), CAS Number 24157-81-1.

2. Magnitude of residue at the time of harvest and method used to determine the residue—i. 2,6-DIPN magnitude of residues in/on potatoes, post harvest storage. Platte conducted studies to determine 2,6-DIPN residues in whole potatoes and peels at various times, up to 180 days, following one to three treatments at the maximum application rate. A liquid chromatograph (HPLC) method was used to measure residues of 2,6-DIPN. Potatoes were treated using a small chamber system that attempted to reproduce a commercial operation on a small-scale. Use of the small chamber system produces worst-case residue values compared to a full-scale commercial operation characterized by use conditions and practices that would tend to reduce residues to a greater extent than the chamber system. When treated once during storage at a rate of 1.2 pounds active ingredient per 600 cwt. of potatoes, and sampled 30 days after treatment (DAT), residues for whole potatoes were 0.22 ppm, 0.28 ppm, and 0.41 ppm (average 0.30 ppm). Under these same conditions, residues in/on the peel were 1.01 ppm, 2.59 ppm, and 2.77 ppm (average 2.12 ppm).

ii. 2,6-DIPN magnitude of residues in/on processing potatoes. A magnitude of the residue study was conducted to determine the effect of processing (i.e., baking, boiling, and frying) on whole red and russet potatoes. Use of the small chamber system produces worst-case residue values compared to a full-scale commercial operation characterized by use conditions and practices that would tend to reduce residues to a greater extent than the chamber system. Potatoes were treated with a thermal fog of 2,6-DIPN, in accordance with standard agronomic practices. Two application scenarios were studied: One 20 ppm active ingredient application and three applications of 20 ppm active ingredient (at 2-hour intervals), totaling 60 ppm active ingredient. A liquid chromatograph (HPLC) method was used to analyze residues of 2,6-DIPN in/on the potatoes at 0 and 72 hours post-treatment.

2,6-DIPN residues for washed whole potatoes were as follows: Whole potatoes treated once (20 ppm) at 0 DAT had residues of 0.17 ppm, 0.26 ppm, 0.27 ppm, 0.15 ppm, 0.21 ppm, and 0.14 ppm. Potatoes treated once (20 ppm) at 3 DAT had residues of 0.14 ppm, 0.08 ppm, 0.18 ppm, 0.09 ppm, 0.25 ppm, and 0.14 ppm. Potatoes treated three times (60 ppm) at 0 DAT had residues of 0.97 ppm, 1.14 ppm, 0.59 ppm, 1.70 ppm, 2.10 ppm, and 1.44 ppm. Potatoes treated three times (60 ppm) at 3 DAT had residues of 0.58 ppm, 0.72 ppm, 0.75 ppm, 1.13 ppm, 0.57 ppm, and 0.48 ppm.

For whole potatoes (3 DAT) baked in aluminum foil, 2,6-DIPN residues were as follows: Potatoes treated once (20 ppm) had residues of 0.08 ppm, 0.08 ppm, and <0.02 ppm. Potatoes treated three times (60 ppm) had residues of 0.50 ppm, 0.07 ppm, and 0.24 ppm.

For whole potatoes (3 DAT) baked without aluminum foil, 2,6-DIPN residues were as follows: Potatoes treated once (20 ppm) had residues of 0.32 ppm, 0.26 ppm, and 0.13 ppm. Potatoes treated three times (60 ppm) had residues of 0.73 ppm, <0.02 ppm, and 0.46 ppm.

For potatoes (3 DAT) french fried, 2,6-DIPN residues were as follows: Potatoes treated once (20 ppm) had residues of 0.07 ppm, 0.04 ppm, and 0.03 ppm. Potatoes treated three times (60 ppm) had residues of 0.11 ppm, 0.06 ppm, and 0.11 ppm.

iii. 2,6-DIPN Determination of residues in/on whole potatoes and potato fractions (flesh and peel). A study was conducted to determine the residues in/on whole potatoes and the potato fractions (flesh and peel). Use of the small chamber system produces worst-case residue values compared to a full-scale commercial operation characterized by use conditions and practices that would tend to reduce residues to a greater extent than the chamber system. A liquid chromatograph (HPLC) method was used to analyze residues of 2,6-DIPN.

2,6-DIPN residues for whole potatoes were as follows: Whole potatoes treated once (20 ppm) at 0 DAT had residues of 0.12 ppm, 0.16 ppm, and 0.11 ppm. Potato peels treated once (20 ppm) at 0 DAT had residues of 1.76 ppm, 1.56 ppm, and 1.46 ppm. Potato flesh samples treated once (20 ppm) at 0 DAT had no detectable residues above the limit of quantification (LOQ) of 0.02 ppm. Peeled potato samples from 0, 30, and 90 DAT were analyzed for residues; however, no residues above the LOQ of 0.02 ppm were detected.

iv. Platte Chemical conducted research on 2,6-DIPN applied to potatoes in storage sheds under an Experimental Use Permit (EUP) during the 1999-2000 use season. This report is a brief summary of the residue data that were collected as part of this research.

2,6-DIPN (Amplify® Sprout Inhibitor; Amplify®) was applied to potatoes in commercial sheds using commercial application equipment at 14 locations during the 1999-2000 use season. The application rates and the days post-treatment (number of days that the potatoes were held prior to release from the shed) varied. The application rates ranged from 11 ppm to 20 ppm, while the days post-treatment ranged from 0 to 215 days. Of the 14 locations examined under the EUP, only one location studied potatoes released 30 days post-treatment. The 30-day holding period is the requirement on the label for the section 3 registration of Amplify®. However, 30 days is quite short for a holding period and would likely only be used if growing conditions were unusual, such as a particularly wet growing season. Hence, most locations studied under the EUP used longer holding periods.

The potatoes at the one location that examined the 30-day holding period were treated at 11.0 ppm. These residue data have been adjusted so that they were on the basis as the application rate used in the magnitude of the residue study. The average residue in whole potatoes as tested under the EUP were 0.032 ppm (at 11 ppm) and 0.058 ppm (adjusted to 20 ppm).

v. Summary. Residues on whole potatoes, especially peeled potatoes, are expected to be quite low. Further, residues are expected to decline from the time potatoes are removed from storage to the time of consumption. In addition, processing studies demonstrate that washing and cooking substantially reduce residues. Results from peeling studies show that quantifiable residues are not expected in the potato flesh. Because of the relatively low residues observed and the impact of processing, dietary exposure to 2,6-DIPN is expected to be minimal.

3. Analytical method. An analytical method for residues is not applicable, as this petition proposes an exemption from the requirement of a tolerance for 2,6-DIPN based on the submitted residue data.

C. Mammalian Toxicological Profile

1. Acute toxicity. Technical 2,6-DIPN exhibits low acute toxicity and is classified as toxicity category IV. The rat oral LD50 is greater than 5,000 milligrams/kilograms (mg/kg) (toxicity category IV), the rabbit dermal LD50 is greater than 5,000 mg/kg (toxicity category IV), and the rat inhalation LC50 is greater than 2.60 mg/L (maximum attainable concentration) (toxicity category IV). In addition, 2,6-DIPN is not a skin sensitizer in guinea pigs, shows slight dermal irritation with reversal at 48 hours in rabbits (toxicity Start Printed Page 48680category IV), and minimal ocular irritation (either redness, discharge or both) clearing by 48 hours (toxicity category IV) in rabbits. The end use formulation is the same as the technical formulation, it contains no intentionally added inert ingredients.

2. Genotoxicity. Short-term assays for genotoxicity consisting of a bacterial reverse mutation assay (Ames test), an in vivo/in vitro unscheduled DNA synthesis in rat primary hepatocytes at two time points, and an in vivo mouse micronucleus assay were conducted with 2,6-DIPN and were negative. A mouse lymphoma study conducted with 2,6-DIPN was weakly positive in the absence of metabolic activation and equivocal in the presence of metabolic activation, in both cases at concentrations showing marked cytotoxicity. Based on a weight of evidence evaluation of mutagenicity data for 2,6-DIPN there is not any concern for genotoxicity of 2,6-DIPN.

3. 90-Day subchronic toxicity study in rats. 2,6-DIPN was administered in the diet to rats (10 animals/sex/group) at doses of 0, 750, 1,500, or 3,000 ppm (or approximately 0, 53.9, 104, and 208 mg/kg/day for males and 0, 61.8, 121, and 245 mg/kg/day for females) for 13 weeks. The no observed adverse effect level (NOAEL) for this study was 1,500 ppm (104 and 121 mg/kg/day for males and females, respectively) in male and female rats and was based on decreased body weight gains and food consumption, and adrenal and kidney toxicity at the lowest observed adverse effect level (LOAEL) of 3,000 ppm (208 and 245 mg/kg/day for males and females, respectively).

4. Developmental toxicity in rats. 2,6-DIPN was administered by gavage to pregnant rats at doses of 0, 50, 150, and 500 mg/kg/day from days 6-19 of gestation. The maternal toxicity NOAEL was 50 mg/kg/day based on decreased body weight and feed consumption at the maternal LOAEL of 150 mg/kg/day. The NOAEL for prenatal developmental toxicity was 150 mg/kg/day based on decreased fetal body weight and a possible treatment-related cartilage anomaly at the developmental LOAEL of 500 mg/kg/day. There is no evidence of teratogenicity or of increased fetal susceptibility to 2,6-DIPN.

5. Metabolism. The metabolism of 2,6-DIPN and di-isopropylnaphthalenes have been investigated, and several references to this work have been found in the published literature. In one study, rats were given a single dose or a daily oral dose for 1 month of 0.1 g/kg bwt. Tissues were evaluated from animals sacrificed 0, 2, 4, 24, and 48 hours following the single dose, and 2, 4, 24 hours, and 7 and 30 days following the repeated dose administration. DIPNs were found predominantly in body fat and subcutaneous fat 2 hours after the dose, with amounts increasing to 24 hours after the dose, and only slightly dropping at 48 hours. Significant distribution of DIPNs to liver, heart, kidney, and brain were seen at 2 hours; material in these compartments was eliminated by 48 hours following the single dose. Following repeated doses, the amount of DIPNs distributed in tissues 2 hours after the last dose was lower than or equivalent to that seen following a single dose. The amount in body and subcutaneous fat 2 hours following the last dose, although approximately two-fold higher than that seen following a single dose, diminished markedly by 30 days post-exposure. The half-life in fat was approximately 7 days. Thus, DIPNs showed a relatively low potential for persistent bioaccumulation.

Another study investigated the urinary metabolites of 2,6-DIPN following a single oral dose. Approximately 23% of the dose was excreted in the urine by 24 hours post-dosing.

6. Other tests. Naphthalene is associated with pulmonary necrosis (following intraperitoneal administration) and carcinogenesis in mice. A study has been reported in the public literature that compared the potential of napthalene, 2-methylnapthalene, 2-isopropylnaphthalene, and 2,6-DIPN to produce pulmonary damage in mice. The study's data suggest that 2,6-DIPN is very unlikely to share either the pulmonary toxicity or the carcinogenicity potential characteristic of napthalene.

No data have been found in the literature that would indicate 2,6-DIPN has any adverse effect on mammalian endocrine or immune systems. No incidents of hypersensitivity or any other adverse effects have been observed in individuals handling the material.

D. Aggregate Exposure

1. Dietary exposure—i. Food—a. Acute dietary exposure. Exposure to chemicals that have the potential to elicit a toxic response after a relatively short period of exposure (acute toxicant) is calculated using a distribution of exposure estimated from the entire consumption data base. The exposure algorithm uses the basic relationship, that exposure is the product of the amount of food consumed and the magnitude of the residue in/on that food.

Residues that are observed in/on crops are found to occur as a distribution. Likewise, food consumption patterns are best described by a consumption distribution. The most realistic calculation of acute dietary exposure, therefore, is to multiply the distribution of residues and the distribution of consumption using the Monte Carlo approach.

For the acute analysis presented here, the Monte Carlo approach was used to estimate dietary exposure from potential residues of 2,6-DIPN in all potatoes. In the Monte Carlo model, the distribution of the residue data for whole raw unwashed potatoes (0.22 ppm to 0.41 ppm) was used in conjunction with individual consumption data for each food. The residue distribution was multiplied by the processing factors (PF) determined from 2,6-DIPN processing studies on baked (PF = 0.10), boiled (PF = 0.078), fried (PF = 0.032), and washed potatoes (PF = 0.15). In addition, it was assumed that 100% of the potatoes consumed would be treated with 2,6-DIPN at the proposed label use rate. That is, no adjustments were made for the percentage of all potatoes that would be stored and treated with 2,6-DIPN, nor potatoes intended for fresh versus processing markets.

The acute exposure estimate at the 99.9th percentile of exposure for the overall U.S. population is 0.000465 mg/kg bw/day. When compared to a maternal toxicity NOAEL of 50 mg/kg bw/day from a developmental toxicity study in rats, the Margin of Exposure (MOE) at the 99.9th percentile of exposure is 107437. For women of child-bearing age, the acute exposure estimate at the 99.9th percentile of exposure is 0.000142 mg/kg bw/day (MOE = 351939). The population subgroup with the highest predicted level of acute exposure was children 1 to 6 years of age. Acute exposures for children 1 to 6 years of age were 0.000682 mg/kg bw/day (MOE = 73309). Because the predicted exposures, expressed as MOEs, are well above 100, there is reasonable certainty that no acute effects would result from dietary exposure to 2,6-DIPN.

b. Chronic dietary exposure. Chronic exposure estimates were calculated for potential residues of 2,6-DIPN in/on all potatoes, including those destined for processing (e.g., frozen, canned). Generally, exposure to chemicals that have the potential to elicit a toxic response after an extended period of exposure (chronic toxicant) is calculated using per-capita mean consumption estimates and an average residue value. As a conservative estimate of potential long-term dietary exposure, it was Start Printed Page 48681assumed that 100% of the potatoes consumed would contain 2,6-DIPN residues at 0.30 ppm (average residue). This residue value was multiplied by the processing factors (PF) determined from 2,6-DIPN processing studies on baked (PF = 0.10), boiled (PF = 0.078), fried (PF = 0.032), and washed potatoes (PF = 0.15).

A risk assessment was performed for 2,6-DIPN using the subchronic toxicity study in rats NOAEL of 104 or 121 mg/kg/day (males and females, respectively). Although the developmental toxicity study indicates a lower NOAEL for the same toxicity (reduced body weight, weight gain, and food consumption), the maternal LOAEL of 150 mg/kg/day is between the subchronic NOAEL of 104-121 mg/kg/day and the LOAEL of 208-245 mg/kg/day. However, the maternal toxicity NOAEL of 50 mg/kg/day is appropriate for use in characterization of risks for the subpopulation of women of childbearing age.

Because of its status as a biopesticide, chronic toxicity studies would not normally be required for 2,6-DIPN; however, a reference dose (RfD) of 1 mg/kg/day can be established for purposes of chronic dietary risk assessment if necessary. The RfD value is based on the NOAEL from the subchronic rat study and use of a 100-fold uncertainty factor (10X for interspecies extrapolation and 10X for intraspecies variability, RfD = 104/100 = 1 mg/kg/day). Retention of an FQPA safety factor is not necessary for 2,6-DIPN. Developmental data in rats showed no unique susceptibility to DIPN.

For the overall U.S. population, chronic exposure was estimated to be 0.000033 mg/kg bwt/day or <0.1 % of the RfD. Chronic exposure also was calculated for women of child-bearing age. Exposure estimates were 0.000019 mg/kg bwt/dw (<0.1 % of the RfD). For the most highly exposed population subgroup, children 1 to 6 years of age, chronic exposure was estimated to be 0.000119 mg/kg bw/day or <0.1 % of the RfD.

ii. Drinking water. There is no established maximum concentration level for 2,6-DIPN in water. Based on the low use rate and an indoor use pattern that is not widespread, residues of 2,6-DIPN in drinking water and exposure from this route is unlikely.

2. Non-dietary exposure. 2,6-DIPN is not registered for any use that could result in non-occupational, non-dietary exposure to the general population.

E. Cumulative Exposure

There is no evidence to indicate or suggest that 2,6-DIPN shares any mechanism of toxicity in common with those of any other pesticides. Therefore, cumulative exposure concerns are not anticipated.

F. Safety Determination

1. U.S. population. The acute exposure estimate at the 99.9th percentile of exposure for the overall U.S. population was 0.000465 mg/kg bwt/day. When compared to a maternal toxicity NOAEL of 50 mg/kg bwt/day from a developmental toxicity study in rats, the MOE at the 99.9th percentile of exposure is 107437. For women of child-bearing age, the acute exposure estimate at the 99.9th percentile of exposure was 0.000142 mg/kg bwt/day (MOE = 351939). For the overall U.S. population, chronic exposure was estimated to be 0.000033 mg/kg bwt/day or <0.1% of the RfD. Chronic exposure also was calculated for women of child-bearing age. Exposure estimates were 0.000019 mg/kg bwt/day (<0.1% of the RfD) for women of child-bearing age.

2. Infants and children. Acute exposures for infants and children 1 to 6 years of age were 0.000682 mg/kg bwt/day (MOE = 73309). For the most highly exposed population subgroup, children 1 to 6 years of age, chronic exposure was estimated to be 0.000119 mg/kg bwt/day or <0.1% of the RfD.

G. Effects on the Immune and Endocrine Systems

Platte has no information to suggest that 2,6-DIPN will adversely affect the immune or endocrine systems. The Agency is not requiring information on endocrine effects of this biochemical pesticide at this time.

H. Existing Tolerances

No codex maximum residue levels are established for residues of 2,6-DIPN in/on any food or feed crop.

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[FR Doc. 01-23482 File 9-20-01; 8:45 am]

BILLING CODE 6560-50-S