Pesticide, food, and feed additive petitions: Valent U.S.A. Corp.,

[Federal Register: December 22, 2004 (Volume 69, Number 245)]

[Notices]

[Page 76724-76729]

From the Federal Register Online via GPO Access [wais.access.gpo.gov]

[DOCID:fr22de04-45]

ENVIRONMENTAL PROTECTION AGENCY

[OPP-2004-0403; FRL-7689-6]

Pyriproxyfen: 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- 2004-0403, must be received on or before January 21, 2005.

ADDRESSES: Comments may be submitted electronically, by mail, or through hand delivery/courier. Follow the detailed instructions as provided in Unit I. of the SUPPLEMENTARY INFORMATION.

FOR FURTHER INFORMATION CONTACT: Joseph Tavano, Registration Division (7505C), Office of Pesticide Programs, Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone number: (703) 305-6411; e-mail address: tavano.joseph@epa.gov.

SUPPLEMENTARY INFORMATION:

1. General Information

   1. Does this Action Apply to Me?

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

      Crop production (NAICS 111)

      Animal production (NAICS 112)

      Food manufacturing (NAICS 311)

      Pesticide manufacturing (NAICS 32532)

      This listing is not intended to be exhaustive, but rather provides a guide for readers regarding entities likely to be affected by this action. Other types of entities not listed in this unit could also be affected. The North American Industrial Classification System (NAICS) codes have been provided to assist you and others in determining whether this action might apply to certain entities. If you have any questions regarding the applicability of this action to a particular entity, consult the person listed under FOR FURTHER INFORMATION CONTACT.

   2. 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-2004-0403. The official public docket consists of the documents specifically referenced in this action, any public comments received, and other information related to this action. Although a part of the official docket, the public docket does not include Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. The official public docket is the collection of materials that is available for public viewing at the Public Information and Records Integrity Branch (PIRIB), Rm. 119, Crystal Mall 2, 1801 S. Bell St., Arlington, VA. This docket facility is open from 8:30 a.m. to 4 p.m., Monday through Friday, excluding legal holidays. The docket telephone number is (703) 305- 5805.

      2. Electronic access. You may access this Federal Register document electronically through the EPA Internet under the ``Federal Register'' listings at http://www.epa.gov/fedrgstr/.

      An electronic version of the public docket is available through EPA's electronic public docket and comment system, EPA Dockets. You may use EPA Dockets at http://www.epa.gov/edocket/ to submit or view public

      comments, access the index listing of the contents of the official public docket, and to access those documents in the public docket that are available electronically. Although not all docket materials may be available electronically, you may still access any of the publicly available docket materials through the docket facility identified in Unit I.B.1. Once in the system, select ``search,'' then key in the appropriate docket ID number.

      Certain types of information will not be placed in the EPA Dockets. Information claimed as CBI and other information whose disclosure is restricted by statute, which is not included in the official public docket, will not be available for public viewing in EPA's electronic public docket. EPA's policy is that copyrighted material will not be placed in EPA's electronic public docket but will be available only in printed, paper form in the official public docket. To the extent feasible, publicly available docket materials will be made available in EPA's electronic public docket. When a document is selected from the index list in EPA Dockets, the system will identify whether the document is available for viewing in EPA's electronic public docket. Although not all docket materials may be available electronically, you may still access any of the publicly available docket materials through the docket facility identified in Unit I.B. EPA intends to work towards providing electronic access to all of the publicly available docket materials through EPA's electronic public docket.

      For public commenters, it is important to note that EPA's policy is that public comments, whether submitted electronically or in paper, 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.

   3. 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

      [[Page 76725]]

      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-2004-0403. 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-2004-0403. 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-2004-0403.

      3. By hand delivery or courier. Deliver your comments to: Public Information and Records Integrity Branch (PIRIB), Office of Pesticide Programs (OPP), Environmental Protection Agency, Rm. 119, Crystal Mall 2, 1801 S. Bell St., Arlington, VA, Attention: Docket ID number OPP-2004-0403. Such deliveries are only accepted during the docket's normal hours of operation as identified in Unit I.B.1.

   4. How Should I Submit CBI to the Agency?

      Do not submit information that you consider to be CBI electronically through EPA's electronic public docket or by e-mail. You may claim information that you submit to EPA as CBI by marking any part or all of that information as CBI (if you submit CBI on disk or CD ROM, mark the outside of the disk or CD ROM as CBI and then identify electronically within the disk or CD ROM the specific information that is CBI). Information so marked will not be disclosed except in accordance with procedures set forth in 40 CFR part 2.

      In addition to one complete version of the comment that includes any information claimed as CBI, a copy of the comment that does not contain the information claimed as CBI must be submitted for inclusion in the public docket and EPA's electronic public docket. If you submit the copy that does not contain CBI on disk or CD ROM, mark the outside of the disk or CD ROM clearly that it does not contain CBI. Information not marked as CBI will be included in the public docket and EPA's electronic public docket without prior notice. If you have any questions about CBI or the procedures for claiming CBI, please consult the person listed under FOR FURTHER INFORMATION CONTACT.

   5. 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 as signed 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.

2. 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: December 9, 2004. Lois Rossi, Director, Registration Division, Office of Pesticide Programs.

   Summary of Petition

   The petitioner 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.

   Valent U.S.A. Corporation

   PP 4F6847

   EPA has received a pesticide petition 4F6847 from Valent U.S.A. Corporation, 1600 Riviera Ave., Suite 200, Walnut

   [[Page 76726]]

   Creek, California 94596-8025 proposing, pursuant to section 408(d) of the Federal Food, Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 346a(d), to amend 40 CFR part 180 by establishing tolerances for residues of pyriproxyfen, 2-[1-methyl-2-(4-phenoxyphenoxy)ethoxy]pyridine (CA), in or on the raw agricultural commodities (RAC) grass forage and hay (crop group 17). EPA has determined that the petition contains data or information regarding the elements set forth in section 408(d)(2) of the FFDCA; however, EPA has not fully evaluated the sufficiency of the submitted data at this time or whether the data supports granting of the petition. Additional data may be needed before EPA rules on the petition.

   1. Residue Chemistry

      1. Plant metabolism. Metabolism of 14C-pyriproxyfen labeled in the phenoxyphenyl ring and in the pyridyl ring has been studied in cotton, apples, tomatoes, lactating goats, and laying hens (and rats). The major metabolic pathways in plants is aryl hydroxylation and cleavage of the ether linkage, followed by further metabolism into more polar products by further oxidation and/or conjugation reactions. However, the bulk of the radio-chemical residue on RAC samples remained as parent. Comparing metabolites detected and quantified from cotton, apple, tomato, goat and hen (and rat) shows that there are no significant metabolites in plants which are not also present in the excreta or tissues of animals. Therefore, the residue of concern is best defined as the parent, pyriproxyfen.

         Ruminant and poultry metabolism studies demonstrated that transfer of administered 14C-residues to tissues was low. Total 14C-residues in goat milk, muscle and tissues accounted for less than 2% of the administered dose, and were less than 1 part per million (ppm) in all cases. In poultry, total 14C-residues in eggs, muscle and tissues accounted for about 2.7% of the administered dose, and were less than 1 ppm in all cases except for gizzard.

      2. Analytical method. Practical analytical methods for detecting and measuring levels of pyriproxyfen (and relevant metabolites) have been developed and validated in/on all appropriate agricultural commodities, respective processing fractions, milk, animal tissues, and environmental samples. The extraction methodology has been validated using aged radio-chemical residue samples from metabolism studies. The methods have been validated in cotton seed, apples, soil, and oranges at independent laboratories. EPA has successfully validated the analytical methods for analysis of cotton seed, pome fruit, nutmeats, almond hulls, and fruiting vegetables. The limit of detection of pyriproxyfen in the methods is 0.01 ppm which will allow monitoring of food with residues at the levels proposed for the tolerances.

      3. Magnitude of residues--i. Grass, forage, fodder, and hay. Twelve field trials in grass were conducted in 2002 and 2003. The analytical data show that the average measured residue in/on grass forage samples was 0.05 ppm (n = 24, [sigma]n-1 = 0.10 ppm) pyriproxyfen. Similarly, the analytical data show that the average measured residue in/on grass hay samples was 0.10 ppm (n = 24, [sigma]n-1 = 0.19 ppm). These data support a proposed tolerance for pyriproxyfen in/on grass forage of 0.5 ppm and grass hay of 1.0 ppm.

         ii. Secondary residues. The proposed new use on grass represents an additional feed commodity. Using established and proposed tolerances to calculate the maximum feed exposure to feed animals, and using the very low potential for residue transfer demonstrated in the milk cow feeding residue study, detectable secondary residues in animal tissues, milk, and eggs are not expected. Therefore, no tolerances are required for these commodities.

         iii. Rotational crops. The results of a confined rotational crops accumulation study indicate that no rotational crop planting restrictions or rotational crop tolerances are required.

   2. Toxicological Profile

      1. Acute toxicity. The acute toxicity of technical grade pyriproxyfen is low by all routes. The compound is classified as Category III for acute dermal and inhalation toxicity, and Category IV for acute oral toxicity, and skin/eye irritation. Pyriproxyfen is not a skin sensitizing agent.

      2. Genotoxicity. Pyriproxyfen does not present a genetic hazard. Pyriproxyfen was negative in the following tests for mutagenicity: Ames assay with and without S9, in vitro unscheduled DNA synthesis in HeLa S3 cells, in vitro gene mutation in V79 Chinese hamster cells, and in vitro chromosomal aberration with and without S9 in Chinese hamster ovary cells.

      3. Reproductive and developmental toxicity. Pyriproxyfen is not a developmental or reproductive toxicant. Developmental toxicity studies have been performed in rats and rabbits, and multigenerational effects on reproduction were tested in rats. These studies have been reviewed and found to be acceptable to the Agency.

         In the developmental toxicity study conducted with rats, technical pyriproxyfen was administered by gavage at levels of 0, 100, 300, and 1,000 milligrams/kilogram/bodyweight day (mg/kg/bwt day) during gestation days 7-17. Maternal toxicity (mortality, decreased bwt gain and food consumption, and clinical signs of toxicity) was observed at doses of 300 mg/kg/bwt day and greater. The maternal no observed adverse effect level (NOAEL) was 100 mg/kg/bwt day. A transient increase in skeletal variations was observed in rat fetuses from females exposed to 300 mg/kg/bwt day and greater. These effects were not present in animals examined at the end of the postnatal period, therefore, the NOAEL for prenatal developmental toxicity was 100 mg/kg/ bwt day. An increased incidence of visceral and skeletal variations was observed postnatally at 1,000 mg/kg/bwt day. The NOAEL for postnatal developmental toxicity was 300 mg/kg/bwt day.

         In the developmental toxicity study conducted with rabbits, technical pyriproxyfen was administered by gavage at levels of 0, 100, 300, and 1,000 mg/kg/bwt day during gestation days 6-18. Maternal toxicity (clinical signs of toxicity including one death, decreased bwt gain and food consumption, and abortions or premature deliveries) was observed at oral doses of 300 mg/kg/bwt day or higher. The maternal NOAEL was 100 mg/kg/bwt day. No developmental effects were observed in the rabbit fetuses. The NOAEL for developmental toxicity in rabbits was 1,000 mg/kg/bwt day.

         In the rat reproduction study, pyriproxyfen was administered in the diet at levels of 0, 200, 1,000, and 5,000 ppm through two generations of rats. Adult systemic toxicity (reduced bwts, liver and kidney histopathology, and increased liver weight) was produced at the 5,000 ppm dose (453 mg/kg/bwt day in males, 498 mg/kg/bwt day in females) during the pre-mating period. The systemic NOAEL was 1,000 ppm (87 mg/ kg/bwt day in males, 96 mg/kg/bwt day in females). No effects on reproduction were produced at 5,000 ppm, the higest dose tested (HDT).

      4. Subchronic toxicity. Subchronic oral toxicity studies conducted with pyriproxyfen technical in the rat, mouse, and dog indicate a low level of toxicity. Effects observed at high dose levels consisted primarily of decreased bwt gain; increased liver weights; histopathological changes in the liver and kidney; decreased red blood cell counts, hemoglobin and hematocrit;

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         altered blood chemistry parameters; and, at 5,000 and 10,000 ppm in mice, adecrease in survival rates. The NOAELs from these studies were 400 ppm (23.5 mg/kg/bwt day for males, 27.7 mg/kg/bwt day for females) in rats, 1,000 ppm (149.4 mg/kg/bwt day for males, 196.5 mg/kg/bwt day for females) in mice, and 100 mg/kg/bwt day in dogs. In a four week inhalation study of pyriproxyfen technical in rats, decreased bwt and increased water consumption were observed at 1,000 mg/m3. The NOAEL in this study was 482 mg/m3.

         A 21-day dermal toxicity study in rats with pyriproxyfen technical did not produce any signs of dermal or systemic toxicity at 1,000 mg/ kg/bwt day, the HDT. In a 21-day dermal study conducted with KNACK[reg]. Insect Growth Regulator, the test material produced a NOAEL of 1,000 mg/kg/bwt day HDT for systemic effects, and a NOAEL for skin irritation of 100 mg/kg/bwt day.

      5. Chronic toxicity. Pyriproxyfen technical has been tested in chronic studies with dogs, rats, and mice. EPA has established a reference dose (RfD) for pyriproxyfen of 0.35 mg/kg/bwt day, based on the NOAEL in female rats from the 2-year chronic/oncogenicity study. Effects cited by EPA in the RfD Tracking Report include negative trend in mean red blood cell volume, increased hepatocyte cytoplasm and cytoplasm: Nucleus ratios, and decreased sinusoidal spaces.

         Pyriproxyfen is not a carcinogen. Studies with pyriproxyfen have shown that repeated high dose exposures produced changes in the liver, kidney, and red blood cells, but did not produce cancerin test animals. No oncogenic response was observed in a rat 2-year chronic feeding/ oncogenicity study or in a seventy-eight week study on mice. The oncogenicity classification of pyriproxyfen is ``E'' (no evidence of carcinogenicity for humans).

         Pyriproxyfen technical was administered to dogs in capsules at doses of 0, 30, 100, 300, and 1,000 mg/kg/bwt day for 1-year. Dogs exposed to dose levels of 300 mg/kg/bwt day or higher showed overt clinical signs of toxicity, elevated levels of blood enzymes and liver damage. The NOAEL in this study was 100 mg/kg/bwt day.

         Pyriproxyfen technical was administered to mice at doses of 0, 120, 600, and 3,000 ppm in diet for 78-weeks. The NOAEL for systemic effects in this study was 600 ppm (84 mg/kg/bwt day in males, 109.5 mg/kg/bwt day in females), and a LOAEL of 3,000 ppm (420 mg/kg/bwt day in males, 547 mg/kg/bwt day in females) was established based on an increase in kidney lesions.

         In a 2-year study in rats, pyriproxyfen technical was administered in the diet at levels of 0, 120, 600, and 3,000 ppm. The NOAEL for systemic effects in this study was 600 ppm (27.31 mg/kg/bwt day in males, 35.1 mg/kg/bwt day in females). A lowest observed adverse effect level (LOAEL) of 3,000 ppm (138 mg/kg/bwt day inmales, 182.7 mg/kg/bwt day in females) was established based on a depression in bwt gain in females.

      6. Animal metabolism. The absorption, tissue distribution, metabolism and excretion of 14C-labeled pyriproxyfen were studied in rats after single oral doses of 2 or 1,000 mg/kg/bwt (phenoxyphenyl and pyridyl label), and after a single oral dose of 2 mg/kg/bwt (phenoxyphenyl label only) following 14 daily oral doses at 2 mg/kg/bwt of unlabelled material. For all dose groups, most (88-96%) of the administered radio-label was excreted in the urine and feces within 2-days after radio- labeled test material dosing, and 92-98% of the administered dose was excreted within 7-days. Seven-days after dosing, tissue residues were generally low, accounting for no more than 0.3% of the dosed 14C. Radio-carbon concentrations in fat were the higher than in other tissues analyzed. Recovery in tissues over time indicates that the potential for bioaccumulation is minimal. There were no significant sex or dose-related differences in excretion or metabolism.

      7. Metabolite toxicology. Metabolism studies of pyriproxyfen in rats, goats, and hens, as well as the fish bioaccumulation study demonstrate that the parent is very rapidly metabolized and eliminated. In the rat, most (88-96%) of the administered radiolabel was excreted in the urine and feces within 2-days of dosing, and 92-98% of the administered dose was excreted within 7-days. Tissue residues were low 7-days after dosing, accounting for no more than 0.3% of the dosed 14C. Because parent and metabolites are not retained in the body, the potentil for acute toxicity from in situ formed metabolites is low. The potential for chronic toxicity is adequately tested by chronic exposure to the parent at the maximum tolerance dose and consequent chronic exposure to the internally formed metabolites.

         Seven metabolites of pyriproxyfen, 4'-OH-pyriproxyfen, 5'3'-OH- pyriproxyfen, desphenyl-pyriproxyfen, POPA, PYPAC, 2-OH-pyridine and 2,5-diOH-pyridine, have been tested for mutagenicity (Ames) and acute oral toxicity to mice. All seven metabolites were tested in the Ames assay with and without S9 at doses up to 5,000 micro-grams per plate or up to the growth inhibitory dose. The metabolites did not induce any significant increases in revertant colonies in any of the test strains. Positive control chemicals showed marked increases in revertant colonies. The acute toxicity to mice of 4'-OH-pyriproxyfen, 5'3'-OH- pyriproxyfen, desphenyl-pyriproxyfen, POPA, and PYPAC did not appear to markedly differ from pyriproxyfen, with all metabolites having acute oral LD50values greater than 2,000 mg/kg/bwt. The two pyridines, 2-OH-pyridine and 2,5-diOH-pyridine, gave acute oral LD50values of 124 (male), and 166 (female) mg/kg/bwt, and 1,105 (male) and 1,000 (female) mg/kg/bwt, respectively.

      8. Endocrine disruption. Pyriproxyfen is specifically designed to be an insect growth regulator and is known to produce juvenoid effects on arthropod development. However, this mechanism-of-action in target insects and other some arthropods has no relevance to any mammalian endocrine system. While specific tests, uniquely designed to evaluate the potential effects of pyriproxyfen on mammalian endocrine systems have not been conducted, the toxicology of pyriproxyfen has been extensively evaluated in acute, sub-chronic, chronic, developmental, and reproductive toxicology studies including detailed histopathology of numerous tissues. The results of these studies show no evidence of any endocrine-mediated effects and no pathology of the endocrine organs. Consequently, it is concluded that pyriproxyfen does not possess estrogenic or endocrine disrupting properties applicable to mammals.

   3. Aggregate Exposure

      1. Dietary exposure. An evaluation of chronic dietary exposure to including both food and drinking water has been performed for the U.S. population and various sub-populations including infants and children. No acute dietary endpoint and dose was identified in the toxicology data base for pyriproxyfen, therefore, the Agency has concluded that there is a reasonable certainty of no harm from acute dietary exposure.

      i. Food. Chronic dietary exposure to pyriproxyfen residues was calculated for the U.S.population and 16 population subgroups assuming tolerance level residues, processing factors from residue studies, and 100 percent of the crop treated (PCT). The analyses included residue data for all existing uses, pending uses, and proposed new uses. The results from

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      several representative subgroups are listed below. Chronic exposure to the overall U.S. population is estimated to be 0.0008 mg/kg/bwt day, representing 0.24% of the RfD. For the most highly exposed sub- population, children 1 to 2 years of age, exposure is calculated to be 0.0009 mg/kg/bwt day, or 0.26% of the RfD in the following Table 1. Generally speaking, the Agency has no cause for concern if total residue contribution for established and proposed tolerances is less than 100% of the RfD.

      Table 1.--Calculated Chronic Dietary Exposures to the Total U.S. Population and Selected Sub-Populations to Pyriproxyfen Residues in Food

      Population Subgroup

      Exposure (mg/kg/bwt day)

      Percent of RfD

      Total U.S. population

      0.00083

      0.24

      Children (1-2 years)

      0.00091

      0.26

      Non-nursing infants(