FLUORIDE ACTION NETWORK PESTICIDE PROJECT
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Cyfluthrin (Bayer). September 25, 1997. Filing of Pesticide Petition. Federal Register.
Note from FAN:
This Notice includes petitions for the insecticides
(1.) Deltamethrin and Tralomethrin; (2.) Cyfluthrin; (3.) Fenvalerate;
(4) Zeta-cypermethrin; (5.) Cypermethrin; (6.) Bifenthrin; (7.) Prallethrin; (8.) Fenpropathrin; (9.) Tefluthrin; (10.) Lambda-cyhalothrin.
We have only included the fluorinated pesticides: 2, 6, 9, 10.
http://www.epa.gov/fedrgstr/EPA-PEST/1997/September/Day-25/p25499.htm
[Federal Register: September 25, 1997 (Volume 62, Number 186)] [Notices] [Page 50337-50367] From the Federal Register Online via GPO Access [wais.access.gpo.gov] [DOCID:fr25se97-68] ----------------------------------------------------------------------- ENVIRONMENTAL PROTECTION AGENCY [PF-767; FRL-5748-2] Notice of Filing of Pesticide Petitions AGENCY: Environmental Protection Agency (EPA). ACTION: Notice. ----------------------------------------------------------------------- SUMMARY: This notice announces the initial filing of pesticide petitions proposing the establishment of regulations for residues of certain pesticide chemicals in or on various food commodities. DATES: Comments, identified by the docket control number PF-767, must be received on or before October 27, 1997. ADDRESSES: By mail submit written comments to: Public Information and Records Integrity Branch, Information Resources and Services Division (7506C), Office of Pesticides Programs, Environmental Protection Agency, 401 M St., SW., Washington, DC 20460. In person bring comments to: Rm. 1132, CM #2, 1921 Jefferson Davis Highway, Arlington, VA. Comments and data may also be submitted electronically to: opp- docket@epamail.epa.gov. Follow the instructions under ``SUPPLEMENTARY INFORMATION.'' No confidential business information should be submitted through e-mail. Information submitted as a comment concerning this document may be claimed confidential by marking any part or all of that information as ``Confidential Business Information'' (CBI). CBI should not be submitted through e-mail. Information marked as CBI will not be disclosed except in accordance with procedures set forth in 40 CFR part 2. A copy of the comment 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. All written comments will be available for public inspection in Rm. 1132 at the address given above, from 8:30 a.m. to 4 p.m., Monday through Friday, excluding legal holidays. FOR FURTHER INFORMATION CONTACT:By mail: George LaRocca, Registration Division [PM-13], Office of Pesticide Programs, 401 M St., SW., Washington, DC 20460. Office location, telephone number and e-mail address: Rm. 204, Crystal Mall #2, 1921 Jefferson Davis Hwy., Arlington, VA, (703) 305-6100, e-mail: larocca.george@epamail.epa.gov. SUPPLEMENTARY INFORMATION: EPA has received pesticide petitions as follows proposing the establishment and/or amendment of regulations for residues of certain pesticide chemicals in or on various food commodities under section 408 of the Federal Food, Drug, and Comestic Act (FFDCA), 21 U.S.C. 346a. EPA has determined that these petitions contain 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 supports granting of the petition. Additional data may be needed before EPA rules on the petition. The official record for this notice of filing, as well as the public version, has been established for this notice of filing under docket control number [PF-767] (including comments and data submitted electronically as described below). 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 official record is located at the address in ``ADDRESSES'' at the beginning of this document. Electronic comments can 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. Comment and data will also be accepted on disks in Wordperfect 5.1 file format or ASCII file format. All comments and data in electronic form must be identified by the docket controlnumber [PF-767] and appropriate petition number. Electronic comments on this notice may be filed online at many Federal Depository Libraries. List of Subjects Environmental protection, Agricultural commodities, Food additives, Feed additives, Pesticides and pests, Reporting and recordkeeping requirements. Dated: September 19, 1997. James Jones, Acting Director, Registration Division, Office of Pesticide Programs. Summaries of Petitions Petitioner summaries of the pesticide petitions are printed below as required by section 408(d)(3) of the FFDCA. The summaries of the petitions were prepared by the petitioners and represent the views of the petitioners. EPA is publishing the petition summaries verbatim without editing them in any way. 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. 2. Bayer Corporation PP 4F3046, 9F3731, 3F4204, 4F4309, 4F4313, 2F4137, 4H5427, 9H5574, 3H5670, 4H5686, 4H5687 EPA has received a request regarding pesticide petitions (PP 4F3046, 9F3731, 3F4204, 4F4309, 4F4313, 2F4137, 4H5427, 9H5574, 3H5670, 4H5686, 4H5687) from Bayer Corporation, 8400 Hawthorn Road, P.O. Box 4913, Kansas City, MO 64210 to remove the time limitations on the established tolerances at 40 CFR Sec. 180.436, Sec. 185.1250 and Sec. 186.1250 for the insecticide cyfluthrin, [cyano[4-fluoro-3- phenoxyphenyl]-methyl-3-[2,2-dicloroethenyl]-2,2-dimethyl- cyclopropanecarboxylate] in or on the raw agricultural commodities alfalfa, forage, at 5.0 ppm; alfalfa, hay, at 10.0 ppm; aspirated grain fractions at 300 ppm; carrots at 0.2 ppm; cattle, fat, at 1.0 ppm; cattle, meat, at 0.4 ppm; cattle, meat by-products (mbyp) at 0.4 ppm; corn, forage (sweet), at 15.0 ppm; corn, fodder (sweet), at 30 ppm; corn (sweet, K+CWHR), at 0.05 ppm; cottonseed at 1.0 ppm; cottonseed, oil, at 2.0 ppm; cottonseed, hulls, at 2.0 ppm; citrus, whole fruit, at 0.2 ppm; citrus oil, at 0.3 ppm; citrus dried pulp, at 0.3 ppm; eggs at 0.01 ppm; goats, fat, at 1.0 ppm; goats, meat, at 0.4 ppm; goats, meat by-products (mbyp) at 0.4 ppm; hogs, fat, at 1.0 ppm; hogs, meat, at 0.4 ppm; hogs, meat by-products (mbyp) at 0.4 ppm; horses, fat, at 1.0 ppm; horses, meat, at 0.4 ppm; horses, meat by-products (mbyp) at 0.4 ppm; milkfat, at 15.0 ppm (representing 0.5 ppm in whole milk); peppers, at 0.5 ppm; poultry, fat, at 0.01 ppm; poultry, meat, at 0.01 ppm; poultry, meat by-products (mbyp) at 0.01 ppm; radishes at 1.0 ppm; sheep, fat, at 1.0 ppm; sheep, meat, at 0.4 ppm; sheep, meat by- products (mbyp) at 0.4 ppm; sorghum, fodder, at 5.0 ppm; sorghum, forage, at 2.0 ppm; sorghum, grain at 4.0 ppm, sunflower, forage, at 1.0 ppm; sunflower, seed, at 0.02 ppm; sugarcane, at 0.05 ppm; sugarcane, molasses, at 0.2 ppm; tomatoes, at 0.2 ppm; tomato, concentrated products, at 0.5 ppm; and tomato, pomace (wet and dry) at 5.0 ppm. All data requested by EPA have been submitted. Therefore, a request for unconditional registration and removal of the time limitations on established tolerances is being made. Consistent with section 408(d) of FFDCA, as recently amended by the Food Quality Protection Act, Bayer submitted a summary and authorization for the summary to be published in the Federal Register in a notice of receipt of the request. The summary represents the views of Bayer; EPA is in the process of evaluating the request. Consistent with section 408(d)(3), EPA is including the summary as a part of this notice of filing. EPA has not fully evaluated the sufficiency of the submitted data at this time or whether the data support granting the request. A. Residue Chemistry 1. Plant metabolism. The metabolism of cyfluthrin in plants is adequately understood. Studies have been conducted to delineate the metabolism of radio labeled cyfluthrin in various crops all showing similar results. The residue of concern is cyfluthrin. 2. Analytical method. Adequate analytical methodology (gas/liquid chromatography with an electron capture detector) is available for enforcement purposes. 3. Magnitude of residues. Cyfluthrin is the active ingredient in the registered end-use product Baythroid 2 Emulsifiable Pyrethroid Insecticide, EPA Reg. No. 3125-351. Baythroid 2 is registered for use on alfalfa, carrots, [[Page 50342]] citrus, cotton, peppers, radishes, sorghum, sugarcane, sweet corn, sunflowers and tomatoes. Tolerances to support these uses were proposed in pesticide petitions 4F3046, 9F3731, 3F4204, 4F4309, 4F4313, 2F4137, and 4F4313 and food/feed additive petitions 4H5427, 9H5574, 3H5670, 4H5686, and 4H5687. Residue data covering all the uses associated with these petitions have been previously submitted to EPA for review and have been found by EPA to support the establishment of the tolerances. Consequently, regulations establishing these tolerances were promulgated in response to these petitions. See [53 FR 30676] (cottonseed), [60 FR 28353] (carrots, radishes, peppers and tomatoes), [60 FR 28353] (sugarcane), [61 FR 10678] (alfalfa, sunflowers, and sweet corn), [61 FR 39883] (sorghum), and [62 FR 25518] (citrus). B. Toxicological Profile The database for cyfluthrin is current and complete. Toxicology data cited in support of these tolerances include: 1. Acute toxicity. There is a battery of acute toxicity studies for cyfluthrin supporting an overall toxicity Category II. 2. Genotoxicty. Mutagenicity tests were conducted, including several gene mutation assays (reverse mutation and recombination assays in bacteria and a Chinese hamster ovary (CHO)/HGPRT assay); a structural chromosome aberration assay (CHO/sister chromatid exchange assay); and an unscheduled DNA synthesis assay in rat hepatocytes. All tests were negative for genotoxicity. 3. Reproductive and developmental toxicity. An oral developmental toxicity study in rats with a maternal and fetal NOEL of 10 milligrams/ kilogram of body weight/day (mg/kg bw/day) (highest dose tested). An oral developmental toxicity study in rabbits with a maternal NOEL of 20 mg/kg bw/day and a maternal Lowest Effect Level (LEL) of 60 mg/kg bw/day, based on decreased body weight gain and decreased food consumption during the dosing period. A fetal NOEL of 20 mg/kg bw/day and a fetal LEL of 60 mg/kg bw/day were also observed in this study. The LEL was based on increased resorptions and increased postimplantation loss. A three-generation reproduction study in rats with systemic toxicity NOELs of 7.5 and 2.5 mg/kg bw/day for parental animals and their offspring, respectively. At higher dose levels, the body weights of parental animals and their offspring were reduced. 4. Subchronic toxicity. A subchronic toxicity feeding study using rats demonstrated a NOEL of 22.5 mg/kg bw/day, the highest dose tested. A 6-month toxicity feeding study in dogs established a NOEL of 5 mg/kg bw/day. The LEL was 15 mg/kg bw/day based on clinical signs and reduced thymus weights. 5. Chronic toxicity. A 12-month chronic feeding study in dogs established a NOEL of 4 mg/kg bw/day. The lowest effect level (LEL) for this study is established at 16 mg/kg bw/day, based on slight ataxia, increased vomiting, diarrhea and decreased body weight. A 24-month chronic feeding/ carcinogenicity study in rats demonstrated a NOEL of 2.5 mg/kg bw/day and LEL of 6.2 mg/kg bw/day, based on decreased body weights in males, decreased food consumption in males, and inflammatory foci in the kidneys in females. A 24-month carcinogenicity study in mice was conducted. Under the conditions of the study there were no carcinogenic effects observed. A 24-month chronic feeding/carcinogenicity study in rats was conducted. There were no carcinogenic effects observed under the conditions of the study. 6. Animal metabolism. A metabolism study in rats showed that cyfluthrin is rapidly absorbed and excreted, mostly as conjugated metabolites in the urine, within 48 hours. An enterohepatic circulation was observed. 7. Metabolite toxicology. No toxicology data have been required for cyfluthrin metabolites. The residue of concern is cyfluthrin. 8. Endocrine effects. There is no evidence of endocrine effects in any of the studies conducted with cyfluthrin, thus, there is no indication at this time that cyfluthrin causes endocrine effects. C. Aggregate Exposure 1. Dietary exposure-- Food. Dietary exposure was estimated using Novigen's Dietary Exposure Evaluation Model (DEEMa) software; results from field trial and processing studies; consumption data from the USDA Continuing Surveys of Food Intake by Individuals (CSFIIs), conducted from 1989 through 1992; and information on the percentages of the crop treated with Cyfluthrin. Cyfluthrin is registered for use in alfalfa, citrus, sweet corn, cotton, sorghum, sunflower, sugarcane, carrots, peppers, radishes and tomatoes. In addition, it has an import tolerance for hops. Various formulations are registered for use in food handling establishments and in combination with another active ingredient, for use in field corn, pop corn and sweet corn. Chronic dietary exposure estimates for the overall U.S. population were 0.5% of the Reference dose (RfD) (0.008 mg/kg bw/day). For the most highly exposed population subgroup, children 1 to 6 years of age, the exposure was estimated to be 0.000062 mg/kg bw/day, or 0.8% of the RfD. Acute dietary exposures were estimated for the overall US population, females 13 years and older, children, ages 1-6 and 7-12 years, infants, non-nursing and nursing. The exposure was compared to the NOEL of 20 mg/kg bw/day to estimate the Margins of Exposures (MOEs). For the overall U.S. population the 95th, 99th and 99.9th percentile of exposure the MOEs were calculated as 29,981; 9,519; and 3,658 respectively. For women aged 13 years and older the 95th, 99th and 99.9th percentile of exposure the MOEs were calculcated as 45,996; 20,103 and 10,011 respectively. Lastly, for the potentially highest exposed population subgroup, non-nursing infants, the 95th, 99th and 99.9th percentile of exposure to the MOEs were calculated at 16,107; 3,072; and 1,343, respectively. 2. Drinking water. Cyfluthrin is immobile in soil, therefore, will not leach into groundwater. Additionally, due the insolubility and lipophilic nature of cyfluthrin, any residues in surface water will rapidly and tightly bind to soil particles and remain with sediment, therefore not contributing to potential dietary exposure from drinking water. A screening evaluation of leaching potential of a typical pyrethroid was conducted using EPA's Pesticide Root Zone Model (PRZM3). Based on this screening assessment, the potential concentrations of a pyrethroid in ground water at 2 meters are essentially zero (much less than 0.001 parts per billion (ppb)). Surface water concentrations for pyrethroids were estimated using PRZM3 and Exposure Analysis Modeling System (EXAMS) using Standard EPA cotton runoff and Mississippi pond scenarios. The maximum concentration predicted in the simulated pond was 52 parts per trillion. Concentration in actual drinking water would be much lower. Based on these analyses, the contribution of water to the dietary risk estimate is negligible. 3. Non-dietary exposure. Non-occupational exposure to cyfluthrin may occur as a result of inhalation or contact from indoor residential, indoor commercial, and outdoor residential uses. Pursuant to the requirements of FIFRA as amended by the Food Quality Protection Act of 1996, non-dietary and aggregate risk analyses for cyfluthrin [[Page 50343]] were conducted. The analyses include evaluation of potential non- dietary acute application and post-application exposures. Non- occupational, non-dietary exposure was assessed based on the assumption that a flea infestation control scenario represents a ``worst case'' scenario. For the flea control infestation scenario indoor fogger, and professional residential turf same day treatments were included for cyfluthrin. Deterministic (point values) were used to present a worse case upper-bound estimate of non-dietary exposure. The non-dietary exposure estimates were expressed as systemic absorbed doses for a summation of inhalation, dermal, and incidental ingestion exposures. These worst-case non-dietary exposures were aggregated with chronic dietary exposures to evaluate potential health risks that might be associated with cyfluthrin products. The chronic dietary exposures were expressed as an oral absorbed dose to combine with the non-dietary systemic absorbed doses for comparison to a systemic absorbed dose (NOEL). Results for each potential exposed subpopulation (of adults, children 1-6 years, and infants <1 year) were compared to the systemic absorbed dose NOEL for cyfluthrin to provide estimates of MOE. The large MOEs for cyfluthrin clearly demonstrate a substantial degree of safety. The total non-dietary MOEs are 3,800, 2,700, and 2,500 for adults, children (1-6 years), and infants (<1 year), respectively. The aggregate MOE for adults is approximately 3,800 and the MOEs for infants and children exceed 2,500. The non-dietary methods used in the analyses can be characterized as highly conservative. This is due to the conservatism inherent in the calculation procedures and input assumptions. An example of this is the conservatism inherent in the jazzercise over representation of residential post-application exposures. It is important to acknowledge that these MOEs are likely to significantly underestimate actual MOEs due to a variety of conservative assumptions and biases inherent in the derivatization of exposure by this method. Therefore, it can be concluded that large MOEs associated with potential non-dietary and aggregate exposures to cyfluthrin will result in little or no health risks to exposed persons. The aggregate risk analysis demonstrates compliance with the health-based requirements of the Food Quality Protection Act of 1996 and supports the continued registration and use of residential, commercial, and agricultural products containing cyfluthrin. D. Cumulative Effects Further, Bayer does not have, at this time, available data to determine whether cyfluthrin has a common mechanism of toxicity with other substances. For the purposes of this tolerance action, therefore, no assumption has been made that cyfluthrin has a common mechanism of toxicity with other substances. Bayer will submit information for EPA to consider concerning potential cumulative effects of cyfluthrin consistent with the schedule established by EPA in the Federal Register of August 4, 1997, (62 FR 42020) and other EPA publications pursuant to the Food Quality Protection Act. E. Safety Determination 1. U.S. population. Based on the exposure assessments described above and on the completeness and reliability of the toxicity data, it can be concluded that total aggregate exposure to cyfluthrin from all uses will utilize less than 1% percent of the RfD for chronic dietary exposures and that MOEs in excess of 1,000 exist for aggregate exposure to cyfluthrin for non-occupational exposure. EPA generally has no concerns for exposures below 100 percent of the RfD, because the RfD represents the level at or below which daily aggregate exposure over a lifetime will not pose appreciable risks to human health. Margins of exposure of 100 or more (300 for infants and children) also indicate an adequate degree of safety. Thus, it can be concluded that there is a reasonable certainty that no harm will result from aggregate exposure to cyfluthrin residues. 2. Infants and children. In assessing the potential for additional sensitivity of infants and children to residues of cyfluthrin, the data from developmental studies in both rat and rabbit and a two-generation reproduction study in the rat can be considered. The developmental toxicity studies evaluate any potential adverse effects on the developing animal resulting from pesticide exposure of the mother during prenatal development. The reproduction study evaluates any effects from exposure to the pesticide on the reproductive capability of mating animals through two generations, as well as any observed systemic toxicity. The toxicology data which support these tolerances include: An oral developmental toxicity study in rats with a maternal and fetal NOEL of 10 mg/kg bw/day (HDT). An oral developmental toxicity study in rabbits with a maternal NOEL of 20 mg/kg bw/day and a maternal LEL of 60 mg/kg bw/day, based on decreased body weight gain and decreased food consumption during the dosing period. A fetal NOEL of 20 mg/kg bw/day and a fetal LEL of 60 mg/kg bw/day were also observed in this study. The LEL was based on increased resorptions and increased postimplantation loss. An oral developmental toxicity study performed with beta- cyfluthrin, the resolved isomer mixture of cyfluthrin, has been submitted to the Agency and is currently under review. A developmental toxicity study in rats exposed via inhalation to liquid aerosols of cyfluthrin revealed developmental toxicity, but only in the presence of maternal toxicity. The developmental NOEL was 0.46 mg/m3 on the basis of reduced placental and fetal weights, and delayed ossification. The NOEL for overt maternal toxicity was < 0.46 mg/m3, the lowest dose tested (LDT). A three-generation reproduction study in rats with systemic toxicity NOELs of 7.5 and 2.5 mg/kg bw/day for parental animals and their offspring, respectively. At higher dose levels, the body weights of parental animals and their offspring were reduced. Another multiple- generation reproduction study in rats has been submitted to the Agency and is currently under review. The Agency used the rabbit developmental toxicity study with a maternal NOEL of 20 mg/kg bw/day to assess acute dietary exposure and determine a MOE for the overall U.S. population and certain subgroups. Since this toxicological endpoint pertains to developmental toxicity the population group of concern for this analysis was women aged 13 and above, the subgroup which most closely approximates women of child- bearing age. The MOE is calculated as the ratio of the NOEL to the exposure. The Agency calculated the MOE to be over 600. Generally, MOE's greater than 100 for data derived from animal studies are regarded as showing no appreciable risk. FFDCA section 408 provides that EPA may apply an additional safety factor for infants and children in the case of threshold effects to account for pre- and post-natal effects and the completeness of the toxicity database. The results of the three-generation study in rats provided evidence suggesting that, with respect to effects of cyfluthrin on body weight, pups were more sensitive than adult rats. Thus, the Agency determined that an additional 3-fold uncertainty factor (UF) should be used in risk assessments to ensure adequate protection of infants and children. [[Page 50344]] Generally, EPA considers MOEs of at least 100 to indicate an adequate degree of safety. With an additional 3 x uncertainty factor, this would be 300 for infants and children. Using the exposure assessments described above and based on the described toxicity data aggregate exposure to infants and children indicate a MOE in excess of 2,500. Thus, it can be concluded that there is a reasonable certainty that no harm will result to infants and children from aggregate exposure to cyfluthrin residues. 3. Conclusions. The available data indicate that there is reasonable certainty of no harm from the aggregate exposure from all currently registered uses of cyfluthrin. Thus, consistent with the provisions of the FFDCA as amended August 3, 1996, the time limitations on established cyfluthrin tolerance should be removed. F. International Tolerances Codex maximum residue levels (MRLs) are established for residues of cyfluthrin on milk (0.01 mg/kg); cottonseed (0.05 mg/kg); peppers, sweet (0.2 mg/kg); and tomatoes (0.5 mg/kg). (Stephanie Willett) ... 6. FMC Corporation, Agricultural Products Group PP 6F3453, 7F3546, 5F4484, and 0E3921 EPA has received a request to remove the time limitations on established tolerances from FMC Corporation, Agricultural Products Group, 1735 Market Street, Philadelphia, Pennsylvania 19103 and from the Interregional Research Project No. 4 (IR-4), New Jersey Agricultural Experiment Station, P.O. Box 231, Rutgers University, New Brunswick, NJ 08903. The request proposes to remove the time limitations on established tolerances for residues of the insecticide bifenthrin ((2-methyl [1,1'-biphenyl]-3-yl) methyl-3-(2-chloro-3,3,3,- trifluoro-1-propenyl)-2,2-dimethylcyclopropanecarboxylate), in or on the raw agricultural commodities cottonseed at 0.5 parts per million (ppm); corn, grain (field, seed, and pop) at 0.05 ppm; hops, dried at 10.0 ppm; and strawberries at 3.0 ppm (established at 40 CFR 180.442). These tolerances were established under [PP] 6F3453, 7F3546, 5F4484, and 0E3921. EPA has determined that the request 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 requests. Additional data may be needed before EPA rules on the requests. A. Residue Chemistry 1. Plant metabolism. The metabolism of bifenthrin in plants is adequately understood. Studies have been conducted to delineate the metabolism of radiolabeled bifenthrin in various crops all showing similar results. The residue of concern is the parent compound only. 2. Analytical method. There is a practical analytical method for detecting and measuring levels of bifenthrin in or on food with a limit of detection that allows monitoring of food with residues at or above the levels set in these tolerances (Gas Chromatography with Electron Capture Detection (GC/ECD) analytical method P-2132M. 3. Magnitude of residues. Crop field trial residue data from studies conducted at the maximum label rates for cotton; corn (field, seed, pop); strawberries, and hops show that the established bifenthrin tolerances on cottonseed of 0.5 ppm; corn, grain (field, seed, and pop) of 0.05 ppm; corn, fodder of 5.0 ppm; corn, forage of 2.0 ppm; strawberries of 3.0 ppm, and hops, dried of 10.0 ppm will not be exceeded when the bifenthrin products labeled for these uses are used as directed. B. Toxicological Profile 1. Acute toxicity. For the purposes of assessing acute dietary risk, FMC has used the maternal NOEL of 1.0 mg/kg/day from the oral developmental toxicity study in rats. The maternal LEL of this study of 2.0 mg/kg/day was based on tremors from day 7-17 of dosing. This acute dietary endpoint is used to determine acute dietary risks to all population subgroups. 2. Genotoxicty. The following genotoxicity tests were all negative: gene mutation in Salmonella (Ames); chromosomal aberrations in Chinese hamster ovary and rat bone marrow cells; HGPRT locus mutation in mouse lymphoma cells; and unscheduled DNA synthesis in rat hepatocytes. 3. Reproductive and developmental toxicity-- a. Parental toxicity. In the rat reproduction study, parental toxicity occurred as decreased body weight at 5.0 mg/kg/day with a NOEL of 3.0 mg/kg/day. There were no developmental (pup) or reproductive effects up to 5.0 mg/kg/day (highest dose tested). b. Post-natal sensitivity. Based on the absence of pup toxicity up to dose levels which produced toxicity in the parental animals, there is no evidence of special post-natal sensitivity to infants and children in the rat reproduction study. 4. Subchronic toxicity. Short- and intermediate-term toxicity. The maternal NOEL of 1.0 mg/ kg/day from the oral developmental toxicity study in rats is also used for short- and intermediate-term margins of exposure (MOE) calculations (as well as acute, discussed in (1) above). The maternal lowest effect level (LEL) of this study of 2.0 mg/kg/day was based on tremors from day 7-17 of dosing. 5. Chronic toxicity--a. The reference dose (RfD) has been established at 0.015 mg/kg/day. This RfD is based on a 1 year oral feeding study in dogs with a NOEL of 1.5 mg/kg/day, based on intermittent tremors observed at the Lowest Observed Effect Level (LOEL) of 3.0 mg/kg/day; an uncertainty factor of 100 is used. b. Bifenthrin is classified as a Group C chemical (possible human carcinogen) based upon urinary bladder tumors in mice; assignment of a Q* has not been recommended. 6. Animal metabolism. The metabolism of bifenthrin in animals is adequately understood. Metabolism studies in rats with single doses demonstrated that about 90% of the [[Page 50353]] parent compound and its hydroxylated metabolites are excreted. 7. Metabolite toxicology. The Agency has previously determined that the metabolites of bifenthrin are not of toxicological concern and need not be included in the tolerance expression. 8. Endocrine disruption. No special studies investigating potential estrogenic or other endocrine effects of bifenthrin have been conducted. However, no evidence of such effects were reported in the standard battery of required toxicology studies which have been completed and found acceptable. Based on these studies, there is no evidence to suggest that bifenthrin has an adverse effect on the endocrine system. C. Aggregate Exposure 1. Dietary exposure-- Food. Tolerances have been established for the residues of bifenthrin, in or on a variety of raw agricultural commodities. Tolerances, in support of registrations, currently exist for residues of bifenthrin on hops; strawberries; corn grain, forage, and fodder; cottonseed; and livestock commodities of cattle, goats, hogs, horses, sheep, and poultry. Additionally, time-limited tolerances associated with emergency exemptions were recently established for broccoli, cauliflower, raspberries, cucurbits, and canola. A pending tolerance for artichokes also exists. For the purposes of assessing the potential dietary exposure for these existing and pending tolerances as well as the existing time-limited tolerances under FIFRA section 18 emergency exemptions, FMC has utilized available information on anticipated residues, monitoring data and percent crop treated as follows: i. Acute exposure and risk. Acute dietary exposure 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 1 day or single exposure. For the purposes of assessing acute dietary risk for bifenthrin, the maternal NOEL of 1.0 mg/kg/day from the oral developmental toxicity study in rats was used. The maternal LEL of this study of 2.0 mg/kg/day was based on tremors from day 7-17 of dosing. This acute dietary endpoint was used to determine acute dietary risks to all population subgroups. Available information on anticipated residues, monitoring data and percent crop treated was incorporated into a Tier 3 analysis, using Monte Carlo modeling for commodities that may be consumed in a single serving. These assessments show that the MOE are significantly greater than the EPA standard of 100 for all subpopulations. The 95th percentile of exposure for the overall U.S. population was estimated to be 0.000362 mg/kg/day (MOE of 2,762); 99th percentile 0.000732 mg/kg/day (MOE of 1,367); and 99.9th percentile 0.002282 mg/kg/day (MOE of 438). The 95th percentile of exposure for all infants < 1 year old was estimated to be 0.000652 mg/ kg/day (MOE of 1,534); 99th percentile 0.001138 mg/kg/day (MOE of 879); and 99.9th percentile 0.001852 mg/kg/day (MOE of 540). The 95th percentile of exposure for nursing infants < 1 year old was estimated to be 0.000193 mg/kg/day (MOE of 5,180); 99th percentile 0.000456 mg/ kg/day (MOE of 2,192); and 99.9th percentile 0.000475 mg/kg/day (MOE of 2,107). The 95th percentile of exposure for non-nursing infants < 1 year old was estimated to be 0.000766 mg/kg/day (MOE of 1,306 ); 99th percentile 0.001203 mg/kg/day (MOE of 832); and 99.9th percentile 0.001977 mg/kg/day (MOE of 506). The 95th percentile of exposure for children 1 to 6 years old (the most highly exposed population subgroup) was estimated to be 0.000632 mg/kg/day (MOE of 1,583); 99th percentile 0.001196 mg/kg/day (MOE of 836); and 99.9th percentile 0.005277 mg/kg/ day (MOE of 190). Therefore, FMC concludes that the acute dietary risk of bifenthrin, as estimated by the dietary risk assessment, does not appear to be of concern. ii. Chronic exposure and risk. The acceptable RfD is based on a NOEL of 1.5 mg/kg/day from the chronic dog study and an uncertainty factor of 100 is 0.015 mg/kg/day. The endpoint effect of concern were tremors in both sexes of dogs at the LEL of 3.0 mg/kg/day. A chronic dietary exposure/risk assessment has been performed for bifenthrin using the above RfD. Available information on anticipated residues, monitoring data, and percent crop treated was incorporated into the analysis to estimate the anticipated residue contribution (ARC). The ARC is generally considered a more realistic estimate than an estimate based on tolerance level residues. The ARC are estimated to be 0.00002 mg/kg body weight (bwt)/day and utilize 0.1% of the RfD for the overall U.S. population. The ARC for non-nursing infants (< 1 year) and children 1-6 years old (subgroups most highly exposed) are estimated to be 0.000042 mg/kg bwt/day and 0.000032 mg/kg bwt/day and utilizes 0.3% and 0.2% of the RfD, respectively. Generally speaking, the EPA has no cause for concern if the total dietary exposure from residues for uses for which there are published and proposed tolerances is less than 100% of the RfD. Therefore, FMC concludes that the chronic dietary risk of bifenthrin, as estimated by the dietary risk assessment, does not appear to be of concern. 2. Drinking water. Laboratory and field data have demonstrated that bifenthrin is immobile in soil and will not leach into groundwater. Other data show that bifenthrin is virtually insoluble in water and extremely lipophilic. As a result, FMC concludes that residues reaching surface waters from field runoff will quickly adsorb to sediment particles and be partitioned from the water column. Further, a screening evaluation of leaching potential of a typical pyrethroid was conducted using EPA's Pesticide Root Zone Model (PRZM3). Based on this screening assessment, the potential concentrations of a pyrethroid in groundwater at depths of 1 and 2 meters are essentially zero (much less than 0.001 parts per billion (ppb)). Surface water concentrations for pyrethroids were estimated using PRZM3 and Exposure Analysis Modeling System (EXAMS) using standard EPA cotton runoff and Mississippi pond scenarios. The maximum concentration predicted in the simulated pond was 0.052 ppb. Concentrations in actual drinking water would be much lower than the levels predicted in the hypothetical, small, stagnant farm pond model since drinking water derived from surface water would normally be treated before consumption. Based on these analyses, the contribution of water to the dietary risk estimate is negligible. Therefore, FMC concludes that together these data indicate that residues are not expected to occur in drinking water. 3. Non-dietary exposure. Analyses were conducted which included an evaluation of potential non-dietary (residential) applicator, post- application and chronic dietary aggregate exposures associated with bifenthrin products used for residential flea infestation control and agricultural/commercial applications. The aggregate analysis conservatively assumes that a person is concurrently exposed to the same active ingredient via the use of consumer or professional flea infestation control products and to chronic level residues in the diet. In the case of potential non-dietary health risks, conservative point estimates of non-dietary exposures, expressed as total systemic absorbed dose (summed across inhalation and incidental ingestion routes) for each relevant product use category (i.e., lawn care) and receptor subpopulation (i.e., adults, children 1-6 years and infants < 1 year) are compared to the systemic [[Page 50354]] absorbed dose NOEL for bifenthrin to provide estimates of the MOEs. Based on the toxicity endpoints selected by EPA for bifenthrin, inhalation and incidental oral ingestion absorbed doses were combined and compared to the relevant systemic NOEL for estimating MOEs. In the case of potential aggregate health risks, the above-mentioned conservative point estimates of inhalation and incidental ingestion non-dietary exposure (expressed as systemic absorbed dose) are combined with estimates (arithmetic mean values) of chronic average dietary (oral) absorbed doses. These aggregate absorbed dose estimates are also provided for adults, children 1-6 years and infants < 1 year. The combined or aggregated absorbed dose estimates (summed across non- dietary and chronic dietary) are then compared with the systemic absorbed dose NOEL to provide estimates of aggregate MOEs. The non- dietary and aggregate (non-dietary + chronic dietary) MOEs for bifenthrin indicate a substantial degree of safety. The total non- dietary (inhalation + incidental ingestion) MOEs for post-application exposure for the lawn care product evaluated was estimated to be > 51,000 for adults, 1,900 for children 1-6 years old and 1,800 for infants < 1 year. The aggregate MOE (inhalation + incidental oral + chronic dietary, summed across all product use categories) was estimated to be 25,000 for adults, 1,800 for children 1-6 years old and 1,600 for infants (< 1 year). It can be concluded that the potential non-dietary and aggregate (non-dietary + chronic dietary) exposures for bifenthrin are associated with substantial margins of safety. D. Cumulative Effects In consideration of potential cumulative effects of bifenthrin and other substances that may have a common mechanism of toxicity, to our knowledge there are currently no available data or other reliable information indicating that any toxic effects produced by bifenthrin would be cumulative with those of other chemical compounds; thus only the potential risks of bifenthrin have been considered in this assessment of its aggregate exposure. FMC intends to submit information for the EPA to consider concerning potential cumulative effects of bifenthrin consistent with the schedule established by EPA in the Federal Register of August 4, 1997 (62 FR 42020) (FRL-5734-6), and other EPA publications pursuant to the FQPA. E. Safety Determination 1. U.S. population. Based on a complete and reliable toxicology data base, the acceptable reference dose (RfD) is 0.015 mg/kg/day, based on a NOEL of 1.5 mg/kg/day from the chronic dog study and an uncertainty factor of 100. Available information on anticipated residues, monitoring data and percent crop treated was incorporated into an analysis to estimate the Anticipated Residue Contribution (ARC) for 26 population subgroups. The ARC is generally considered a more realistic estimate than an estimate based on tolerance level residues. The ARC are estimated to be 0.00002 mg/kg body weight (bwt)/day and utilize 0.1% of the RfD for the overall U.S. population. The ARC for non-nursing infants (< 1 year) and children 1-6 years old (subgroups most highly exposed) are estimated to be 0.000042 mg/kg bwt/day and 0.000032 mg/kg bwt/day and utilizes 0.3% and 0.2% of the RfD, respectively. Generally speaking, the EPA has no cause for concern if the total dietary exposure from residues for uses for which there are published and proposed tolerances is less than 100% of the RfD. Therefore, FMC concludes that the chronic dietary risk of bifenthrin, as estimated by the aggregate risk assessment, does not appear to be of concern. For the overall U.S. population, the calculated MOE at the 95th percentile was estimated to be 2,762; 1,367 at the 99th percentile; and 438 at the 99.9th percentile. For all infants < 1 year old, the calculated MOE at the 95th percentile was estimated to be 1,534; 879 at the 99th percentile; and 540 at the 99.9th percentile. For nursing infants < 1 year old, the calculated MOE at the 95th percentile was estimated to be 5,180; 2,192 at the 99th percentile; and 2,107 at the 99.9th percentile. For non-nursing infants < 1 year old, the calculated MOE at the 95th percentile was estimated to be 1,306; 832 at the 99th percentile; and 506 at the 99.9th percentile. For the most highly exposed population subgroup, children 1-6 years old, the calculated MOE at the 95th percentile was estimated to be 1,583; 836 at the 99th percentile; and 190 at the 99.9th percentile. Therefore, FMC concludes that there is reasonable certainty that no harm will result from acute exposure to bifenthrin. 2. Infants and children-- a. General. In assessing the potential for additional sensitivity of infants and children to residues of bifenthrin, FMC considered data from developmental toxicity studies in the rat and rabbit, and a two-generation reproductive study in the rat. The developmental toxicity studies are designed to evaluate adverse effects on the developing organism resulting from pesticide exposure during prenatal development to one or both parents. Reproduction studies provide information relating to effects from exposure to the pesticide on the reproductive capability of mating animals and data on systemic toxicity. FFDCA section 408 provides that EPA may apply an additional 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 data base. b. Developmental toxicity studies. In the rabbit developmental study, there were no developmental effects observed in the fetuses exposed to bifenthrin. The maternal NOEL was 2.67 mg/kg/day based on head and forelimb twitching at the LOEL of 4 mg/kg/day. In the rat developmental study, the maternal NOEL was 1 mg/kg/day, based on tremors at the LOEL of 2 mg/kg/day. The developmental (pup) NOEL was also 1 mg/kg/day, based upon increased incidence of hydroureter at the LOEL 2 mg/kg/day. There were 5/23 (22%) litters affected (5/141 fetuses since each litter only had one affected fetus) in the 2 mg/kg/day group, compared with zero in the control, 1, and 0.5 mg/kg/day groups. According to recent historical data (1992-1994) for this strain of rat, incidence of distended ureter averaged 11% with a maximum incidence of 90%. c. Reproductive toxicity study. In the rat reproduction study, parental toxicity occurred as decreased body weight at 5.0 mg/kg/day with a NOEL of 3.0 mg/kg/day. There were no developmental (pup) or reproductive effects up to 5.0 mg/kg/day (highest dose tested). d. Pre- and post-natal sensitivity-- i. Pre-natal. Since there was not a dose-related finding of hydroureter in the rat developmental study and in the presence of similar incidences in the recent historical control data, the marginal finding of hydroureter in rat fetuses at 2 mg/kg/day (in the presence of maternal toxicity) is not considered a significant developmental finding. Nor does it provide sufficient evidence of a special dietary risk (either acute or chronic) for infants and children which would require an additional safety factor. ii. Post-natal. Based on the absence of pup toxicity up to dose levels which produced toxicity in the parental animals, there is no evidence of special post-natal sensitivity to infants and children in the rat reproduction study. e. Conclusion. Based on the above, FMC concludes that reliable data support use of the standard 100-fold uncertainty factor, and that an additional uncertainty factor is not needed to protect the safety of infants [[Page 50355]] and children. As stated above, aggregate exposure assessments utilized significantly less than 1% of the RfD for either the entire U.S. population or any of the 26 population subgroups including infants and children. Therefore, it may be concluded that there is reasonable certainty that no harm will result to infants and children from aggregate exposure to bifenthrin residues. F. International Tolerances There are no Codex, Canadian, or Mexican residue limits for residues of bifenthrin in or on cotton; corn, field, seed, pop; strawberries; or hops. (Adam Heyward) ... 9. Zeneca Ag Products PP 7G3518, 7F3521, 4F4406 EPA has received a request from Zeneca Ag Products, P. O. Box 15458, Wilmington, DE, 19850-5458 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 removing the time limitation for tolerances established for residues of the insecticide and pyrethriod Tefluthrin in or on the raw agricultural commodities corn, grain, field and pop; corn, forage and fodder, field, pop and sweet; and corn, fresh (including sweet K and corn with huskremoved (CWHR)) at 0.06 ppm. The International Union of Pure and Applied Chemist (IUPAC) name for tefluthrin is (2,3,5,6-tetrafluro-4-methylphenyl)methyl-(1 alpha, 3 alpha)-(Z)-(+/-)-3(2-chloro-3,3,3-trifluoro-1-propenyl)-2,2- dimethylcyclopropanecarboxylate) and its metabolite (Z)-3-(2-chloro- 3,3,3-trifluroro-1-propenyl)-2,2-dimethylcyclopropanecarboxylic acid. The tolerances were originally requested in Pesticide Petition Numbers 7G3518, 7F3521, and 4F4406. EPA has determined that the petition contains data or information regarding the elements set forth in section 408(d)(2) of the FFDCA; however, EPA has not fully evaluated the sufficiency of the submitted data at this time or whether the data supports granting of the petition. Additional data may be needed before EPA rules on the petition. A. Residue Chemistry 1. Plant metabolism. The nature of tefluthrin residues in plants and animals for corn use is adequately understood. The residue of concern is tefluthrin and its metabolite. There is no reasonable expectation of secondary residues in animal tissues and milk from the use as delineated in 40 CFR 180.6(a)(3). 2. Analytical method. An adequate analytical method, gas liquid chromatography with an electron capture detector, is available for enforcement purposes. The enforcement methodology has been submitted to the Food and Drug Administration, and is published in the Pesticide Analytical Manual Vol. II (PAM II). 3. Magnitude of residues. Tefluthrin (also know as FORCEInsecticide) is an effective granular soil insecticide registered for use against a number of soil corn pest; the most economically significant being soil dwelling pest, such as corn rootworm, wireworm, cutworm, and white grubs. Residue data covering all the uses associated with the permanent tolerances requested by this petition have been previously submitted to EPA for review and have been found by EPA to support the requested tolerances. See February 1, 1989 (54 FR 5080); and May 3, 1996 (61 FR 19852) (FRL-5358-5). B. Toxicological Profile 1. Acute toxicity. Acute toxicity studies with the technical grade of the active ingredient tefluthrin: Oral LD 50 in the rat is 22 mg/kg) for (males) and 35 mg/kg for (females); dermal LD50 in the rat is 316 mg/kg in (males) and 177 mg/kg in (females); acute inhalation LC50 in the rat is 0.04 milligram/liter (mg/l) and 0.05 mg/l in female and male rats, respectively; primary eye irritation in the rabbit study showed slight irritation; primary dermal irritation in the rabbit study showed none to slight irritation, and the dermal sensitization in the guinea pig study showed no skin sensitization. 2. Genotoxicty. The following genotoxicity test were all negative: A gene mutation assay (Ames), dominant lethal (mouse in vivo), mouse micronucleus (in vivo), acute cytogenetic study in the rat, unscheduled DNA synthesis and a mouse lymphoma cells test. 3. Reproductive and developmental toxicity. In a rat developmental study, [[Page 50363]] delayed ossification was noted in the highest dose group (5 mg/kg/day), along with significant maternal toxicity (decreased body weight (bwt)). The developmental no observed effect level (NOEL) for this study was established at 3 mg/kg/day. However, the effects observed were most likely a secondary effect resulting from maternal stress. In a developmental toxicity study in rabbits given gavage doses of 0, 3, 6, and 12 mg/kg/day, the maternal NOEL is 3 mg/kg/day and the developmental NOEL is > 12 mg/kg/day. No developmental effects were observed under the conditions of the study. In a rat multi-generation reproduction study, conducted at 0, 15, 50, and 250 ppm with tefluthrin in the diet, a reproductive NOEL was established at 50 ppm (3.4 mg/kg/day) based on reduced pup weight and litter size observed at 250 ppm (12.5 mg/kg/day). Parental toxicity (in the form of abnormal, sprayed, or high-stepping gait) was also observed at 250 ppm. Thus, the effects observed in offspring at 250 ppm is considered to be secondary to maternal toxicity. 4. Subchronic toxicity. A 90-day feeding study in which rats were fed doses of 0, 50, 150, and 350 ppm with a NOEL of 50 ppm and a lowest observed effect level (LOEL) of 150 ppm based on mild dose changes in hemoglobin, cholesterol, and liver weight. A 90-day feeding study in which dogs were fed doses of 0, 0.1, 0.5, and 1.5 mg/kg with a NOEL of 0.5 mg/kg and a LOEL of 1.5 mg/kg based on increased triglycerides and AST. A 21-day dermal study in which rats were exposed dermally to doses of 1, 5, and 50 mg/kg/day, 6 hours/day with a toxicological NOEL of 1mg/kg. 5. Chronic toxicity. A 12-month feeding study in dogs was conducted with a NOEL of 0.5 mg/kg/day. The LOEL for this study is established at 2 mg/kg/day based upon ataxia. A 24-month rat and mouse chronic feeding/oncogenicity studies were conducted with systemic NOEL's of 1.1mg/kg/day and 3.4 mg/kg/day with no oncogenic effects observed at dose levels up to and including 18.2 mg/kg/day and 54.4 mg/kg/day, the highest dose levels tested for rats and mice, respectively. 6. Animal metabolism. A metabolism study in the rat demonstrated that distribution patterns and excretion rates in multiple oral dosing periods are similar to single-dose studies. The metabolism of tefluthrin in livestock has been studied in the goat and chicken. The nature of tefluthrin residue in animals for corn use is adequately understood. The residue of concern is tefluthrin and its metabolite. There is no reasonable expectation of secondary residues in animal tissues and milk from the use as delineated in 40 CFR 180.6(a)(3). 7. Metabolite toxicology. The nature of tefluthrin residue in plants and animals for corn use is adequately understood. The residue of concern is tefluthrin and its metabolite. There is no reasonable expectation of secondary residues in animal tissues and milk from the use as delineated in 40 CFR 180.6(a)(3). An adequate analytical method, gas liquid chromatography with an electron capture detector, is available for enforcement purposes. The enforcement methodology has been submitted to the Food and Drug Administration, and is published in the Pesticide Analytical Manual Vol. II (PAM II). 8. Endocrine disruption. EPA is required to develop a screening program to determine whether certain substances (including all pesticides and inerts) ``may have an effect produced by a naturally occurring estrogen, or such other endocrine effect... .'' The Agency is currently working with interested stakeholders, including other government agencies, public interest groups, industry and research scientists, in developing a screening and testing program and a priority setting scheme to implement this program. Congress has allowed 3 years from passage of the Food Quality Protection Act (FQPA) (August 3, 1999) to implement this program. At that time, EPA may require further testing of this active ingredient and end use products for endocrine disrupter effects. C. Aggregate Exposure The primary source of human exposure to tefluthrin will be from ingestion of raw and processed food commodities which have been treated with tefluthrin. These commodities include corn, grain, field and pop; corn, forage and fodder, field, pop and sweet; and corn, fresh (including sweet K and CWHR) as listed in 40 CFR 180.440. There is no reasonable expectation of secondary residues in animal tissues, milk, or eggs from use as delineated in 40 CFR 180.6(a)(3). 1. Dietary exposure. For purposes of assessing the potential dietary exposure under these tolerances, aggregate exposure is estimated based on the Theoretical Maximum Residue Contribution (TMRC) from the existing tolerances for tefluthrin in food crops. The TMRC is obtained by multiplying the tolerance level residues by the consumption data which estimates the amount of those food products eaten by various population subgroups. The following assumptions were used in conducting this exposure assessment: 100 percent of the crops were treated, and the raw agricultural commodities (RAC) residues would be at the level of the tolerance. This results in an overestimate of human exposure and a conservative assessment of risk. 2. Food. The acute dietary risk assessment used tolerance level residues and assumed that 100 percent of all crops were treated. Thus, this acute dietary exposure estimate is considered ``worst-case'' and severely overestimates potential exposure. The acute dietary Margin of Exposure (MOE) for the most highly exposed population subgroup was children ages one to six. The MOE's were 2,436 at the 95th percentile, 1,342 at the 99th percentile, and 738 at the 99.9th percentile. EPA concludes that there is a reasonable certainty of no harm for MOE of 100 or greater. Therefore, the acute dietary risk assessment for tefluthrin clearly indicates a reasonable certainty of no harm. For the chronic dietary assessment Zeneca used the standard EPA conservative exposure assumptions (i.e. tolerance level residues and 100 percent market share), and based on the completeness and reliability of the toxicity data Zeneca has concluded that the aggregate exposure to this chemical will utilize less than one percent (0.40 percent) of the reference dose (RfD) for the U. S. population. The most highly exposed population subgroup was children ages one to six with a total dietary exposure of 0.000049 mg/kg bwt/day (1.0 percent of the RfD). Since EPA generally has no concern for exposures below 100 percent of the RfD, there is a reasonable certainty that no harm will result from aggregate exposure to residues. 3. Drinking water. Tefluthrin is immobile in soil and, therefore, will not leach into ground water. Additionally, due to the insolubility and lipophilic nature of tefluthrin, any residues in surface water will rapidly and tightly bind to soil particles and remain with sediment, therefore not contributing to potential dietary exposure from drinking water. A screening evaluation of leaching potential of a typical synthetic pyrethroid was conducted using EPA's Pesticide Root Zone Model (PRZM3). Based on this screening assessment, potential concentrations of a pyrethroid in ground water at depths of 1 to 2 meters are essentially zero (<0.001 ppb). Surface water concentrations for pyrethroids were estimated using PRZM3 and Exposure Analysis [[Page 50364]] Modeling Systems (EXAMS) using standard EPA cotton runoff and Mississippi pond scenarios. The maximum concentration predicted in the simulated pond was 0.052 ppb. Concentrations in actual drinking water would be much lower than the levels predicted in the hypothetical, small, stagnant farm pond model since drinking water derived from surface water would normally be treated before consumption. Based on these analyses, the contribution of water to the dietary risk estimate is negligible. 4. Non-dietary exposure. The potential for non-occupational exposure to the general population is expected to be essentially zero. Tefluthrin is not registered for aquatic and/or domestic outdoor or indoor uses. The major use (corn) is applied only once per year at planting as a granular formulation. The other use is limited to commercial seed treatment of field corn, popcorn, seedcorn, and sweet corn seed. There is a commercial use in liquid slurry seed treaters and seed coating equipment, which is not for use on agricultural establishments in hopper-box, planter-box, slurry-box, or other seed treatment applications. The other minor use is for the treatment of fire ants for containerized and balled nursery stock under the USDA/ APHIS Imported Fire Ant Quarantine Program (Department of Agriculture- Animal and Plant Health Inspection Service-7 CFR part 301). D. Cumulative Effects Zeneca will submit information for EPA to consider concerning potential cumulative effects of tefluthrin consistent with the schedule established by EPA on August 4, 1997 (62 FR 42020) (FRL-5734-6) and other EPA publications pursuant to the FQPA. At this time, Zeneca cannot make a determination, based on available and reliable information, that tefluthrin and other substances that may have a common mechanism of toxicity would have cumulative effects. Therefore, for purposes of this request it is appropriate only to consider the potential risks of tefluthrin in an aggregate exposure assessment. E. Safety Determination 1. U.S. population. EPA recently reviewed all of the toxicity end points for the synthetic pyrethroids. Based on this review EPA concluded that the chronic RfD is 0.005 mg/kg/day. This RfD is based on a 1-year dog feeding study with a NOEL of 0.5 mg/kg/day for ataxia, and a 100-fold uncertainty factor. In addition, EPA derived an acute NOEL of 0.5 mg/kg/day for use in acute dietary risk assessment. This NOEL is based on the 1-year dog feeding study in which increased incidence of tremors in both sexes of dogs was observed on the first day of dosing. Using these RfD's and EPA's standard default assumptions (i.e. tolerance level residues and 100 percent market share), Zeneca assessed the potential acute and chronic dietary risk to the general U.S. population and 22 subpopulations. These analyses are considered ``worst-case'', and the results concluded that for the U.S. population, uses were 0.000021 mg/kg/day (0.4 of the RfD). The acute MOE's at the 95th, 99th, and 99.9th percentile were 5.195, 2,449, and 1,091 respectively. The most highly exposed population subgroup (children ages one to six), utilizes 1.0 percent of the chronic RfD, and the acute dietary MOE's at the 95th, 99th, and 99.9th percentiles were 2,436, 1,342, and 738, respectively. These assessments indicate a reasonable certainty that no harm will result from aggregate exposure to residues. 2. Infants and children. Section 408 of the FFDCA provides that EPA shall apply an additional 10-fold 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. EPA generally defines the level of appreciable risk as exposure that is greater than \1/100\ of the NOEL in the animal study appropriate to the particular risk assessment. This 100-fold uncertainty (safety) factor/margin of exposure is designed to account for combined inter- and intra-species variability. EPA believes that reliable data support using the standard 100-fold margin/factor, not the additional 10-fold margin/factor, when EPA has a complete database under existing guidelines and when the severity of the effect in infants and children or the potency or unusual toxic properties of a compound do not raise concerns regarding the adequacy of the standard margin/factor. In assessing the potential for additional sensitivity of infants and children to residues of tefluthrin, EPA considered the data from oral developmental toxicity studies in the rat and rabbit, as well as data from a multi-generation reproduction study in the rat. The developmental toxicity studies are designed to evaluate adverse effects in the developing organism resulting from pesticide exposure during prenatal development in the mothers. Reproduction studies provide information relating to effects from exposure to the pesticide on the reproductive capability of mating animals and data on systemic toxicity. 3. Pre-natal effects. In a rat developmental study delayed ossification was noted in the highest dose group (5 mg/kg/day), along with significant maternal toxicity (decreased bwt). The developmental NOEL for this study was established at 3 mg/kg/day. However, the effects observed were most likely a secondary effect resulting from maternal stress. In a developmental toxicity study in rabbits given gavage doses of 0, 3, 6, and 12 mg/kg/day the maternal NOEL is 3 mg/kg/day, and the developmental NOEL is > 12 mg/kg/day. No developmental effects were observed under the conditions of the study. 4. Post-natal effects. In a rat multi-generation reproduction study conducted at 0, 15, 50, and 250 ppm with tefluthrin in the diet, a reproductive NOEL was established at 50 ppm (3.4 mg/kg/day), based on reduced pup weight and litter size observed at 250 ppm (12.5 mg/kg/ day). Parental toxicity (in the form of abnormal, sprayed, or high- stepping gait) was also observed at 250 ppm. Thus, the effects observed in offspring at 250 ppm is considered to be secondary to maternal toxicity. In EPA's review of the toxicity endpoints for tefluthrin they concluded that the data on developmental and reproductive toxicity tests do not indicate any increased pre- or post-natal sensitivity. Therefore, EPA concluded that reliable data support use of a 100-fold safety factor, and additional 10-fold safety factor is not needed. This aggregate assessment of tefluthrin clearly demonstrates that there is no harm for all population groups. F. International Tolerances There are no Codex Maximum Residue Levels (MRL's) established for tefluthrin. (John Hebert) 10. Zeneca Ag Products PPs 7F3560, 7H5543, 7F3488, 1F3952, 1H5607, 1F3992, 2F4109, 2F4100, 2F4114, 1F3985, and 6F4769 EPA has received a request from Zeneca Ag Products, 1800 Concord Pike, P.O. Box 15458, Wilmington, Delaware 19850-5458, 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 180.438 by removing the time limitation for tolerances established for residues of lambda- cyhalothrin and its epimer in or on the following crops and commodities: broccoli at 0.4 ppm; [[Page 50365]] cabbage at 0.4 ppm; cattle, fat at 3.0 ppm; cattle, meat at 0.2 ppm; cattle, meat and meat by-products (mbyp) at 0.2 ppm; corn, grain (field and pop) at 0.05 ppm; corn, fodder at 1.0 ppm; corn, forage at 6.0 ppm; corn, sweet (k+kwhr) at 0.05 ppm; cottonseed at 0.05 ppm; dry bulb onion at 0.1 ppm; eggs at 0.01 ppm; garlic at 0.1 ppm; goats, fat at 3.0 ppm; goats, meat at 0.2 ppm; goats, mbyp at 0.2 ppm, hogs, fat at 3.0 ppm; hogs, meat at 0.2 ppm; hogs, mbyp at 0.2 ppm; horses, fat at 3.0 ppm; horses, meat at 0.2 ppm; horses, mbyp at 0.2 ppm; lettuce, head at 2.0 ppm; milk, fat (reflecting 0.2 ppm in whole milk) at 5.0 ppm; peanuts at 0.05 ppm; peanuts, hulls at 0.05 ppm; poultry, fat at 0.01 ppm; poultry, meat at 0.01 ppm; poultry, mbyp at 0.01 ppm; rice, grain at 1.0 ppm; rice, hulls at 5.0 ppm; rice, straw at 1.8 ppm; sheep, fat at 3.0 ppm; sheep, meat at 0.2 ppm; sheep, mbyp at 0.2 ppm; soybeans at 0.01 ppm; sorghum, grain at 0.02 ppm; sorghum, grain dust at 1.5 ppm; sunflower, seeds at 0.2 ppm; sunflower, forage at 0.2 ppm; tomatoes at 0.1 ppm; wheat, grain at 0.05 ppm; wheat, forage at 2.0 ppm; wheat, hay at 2.0 ppm; wheat, straw at 2.0 ppm; wheat, grain dust at 2.0 ppm; corn, grain flour at 0.15 ppm; sunflower, oil at 0.30 ppm; sunflower, hulls at 0.50 ppm; tomato pomace (dry or wet) at 6.0 ppm; and wheat, bran at 0.2 ppm. The IUPAC name for lambda-cyhalothrin is a 1:1 mixture of (S)-alpha-cyano-3-phenoxybenzyl-(Z)-(1R,3R)-3-(2-chloro- 3,3,3-trifluoroprop-1-enyl)-2,2-dimethylcyclopropanecarboxylate and (R)-alpha-cyano-3-phenoxybenzyl-(Z)-(1S,3S)-3-(2-chloro-3,3,3- trifluoroprop-1-enyl)-2,2-dimethylcyclopropanecarboxylate and the epimer of lambda-cyhalothrin is a 1:1 mixture of (S)-alpha-cyano-3- phenoxybenzyl-(Z)-(1S,3S)-3-(2-chloro-3,3,3-trifluoroprop-1-enyl)-2,2- dimethylcyclopropanecarboxylate and (R)-alpha-cyano-3-phenoxybenzyl- (Z)-(1R,3R)-3-(2-chloro-3,3,3-trifluoroprop-1-enyl)-2,2- dimethylcyclopropanecarboxylate. These tolerances were originally requested in Pesticide Petition Numbers 7F3560, 7H5543, 7F3488, 1F3952, 1H5607, 1F3992, 2F4109, 2F4100, 2F4114, 1F3985, and 6F4769. EPA has determined that the petitions 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 the request. Additional data may be needed before EPA rules on the request. A. Residue Chemistry 1. Plant metabolism.The metabolism of lambda-cyhalothrin has been studied in cotton, soybean, cabbage and wheat plants. The studies show that the metabolism generally follows that of other pyrethroid insecticides. The ester linkage is cleaved to form cyclopropanecarboxylic acids and the corresponding phenoxybenzyl alcohol. Overall the studies show that unchanged lambda-cyhalothrin is the principal constituent of the residue on edible portions of these crops. 2. Analytical method. An adequate analytical method (gas liquid chromatography with an electron capture detector) is available for enforcement purposes. 3. Magnitude of residues. Field residue trials, meeting EPA study requirements, have been conducted for each crop in this petition. These data have previously been reviewed and classified by the Agency as supportive of these tolerances. B. Toxicological Profile The following toxicity studies have been conducted to support this request. 1. Acute toxicity. Acute toxicity studies with the technical grade of the active ingredient lambda-cyahothrin: oral LD50 in the rat of 79 millgrams/kilogram (mg/kg) (males) and 56 mg/kg (females), dermal LD50 in the rat of 632 mg/kg (males) and 696 mg/kg females, primary eye irritation study showed mild irritation and primary dermal irritation study showed no irritation. 2. Genotoxicty. The following genotoxicity tests were all negative: a gene mutation assay (Ames), a mouse micronucleus assay, an in-vitro cytogenetics assay, and a gene mutation study in mouse lymphoma cells. 3. Reproductive and developmental toxicity. A three-generation reproduction study in rats fed diets containing 0, 10, 30, and 100 ppm with no developmental toxicity observed at 100 ppm, the highest dose tested. The maternal NOEL and LOEL for the study are established at 30 (1.5 mg/kg/day) and 100 ppm (5 mg/kg/day), respectively, based upon decreased parental body weight gain. The reproductive NOEL and LOEL are established at 30 (1.5 mg/kg/day) and 100 ppm (5 mg/kg/day), respectively, based on decreased pup weight gain during weaning. A developmental toxicity study was conducted in rats given gavage doses of 0, 5, 10, and 15 mg/kg/day with no developmental toxicity observed under the conditions of the study. The developmental NOEL is greater than 15 mg/kg/day, the highest dose tested. The maternal NOEL and LOEL are established at 10 and 15 mg/kg/day, respectively, based on reduced body weight gain. A developmental toxicity study was conducted in rabbits given gavage doses of 0, 3, 10, and 30 mg/kg/day with no developmental toxicity observed under the conditions of the study. The maternal NOEL and LOEL are established at 10 and 30 mg/kg/day, respectively based on decreased body weight gain. The developmental NOEL is greater than 30 mg/kg/day, the highest dose tested. 4. Subchronic toxicity. A 90-day feeding study in rats fed doses of 0, 10, 50 and 250 ppm with a NOEL of 50 ppm and a LOEL of 250 ppm based on body weight gain reduction. A study where lambda-cyhalothrin in olive oil was applied to the skin of rats for 21 successive days at dose rates of 1, 10, or 100 (reduced to 50 after 2-3 applications) mg/kg/day. A NOEL of 10 mg/kg/ day is based on clinical signs of slight general toxicity at 50 mg/kg/ day. 5. Chronic toxicity. A 12-month feeding study was conducted in dogs fed dose (by capsule) levels of 0, 0.1, 0.5, 3.5 mg/kg/day with a NOEL of 0.1 mg/kg/day. The LOEL for this study is established at 0.5 mg/kg/ day based upon clinical signs of neurotoxicity. A 24-month chronic feeding/carcinogenicity study was conducted with rats fed diets containing 0, 10, 50, and 250 ppm. The NOEL was established at 50 ppm and LOEL at 250 ppm based on reduced body weight gain. There were no carcinogenic effects observed under the conditions of the study. A carcinogenicity study was conducted in mice fed dose levels of 0, 20, 100, or 500 ppm (0, 3, 15, or 75 mg/kg/day) in the diet for 2 years. A systemic NOEL was established at 100 ppm and systemic LOEL at 500 ppm based on decreased body weight gain in males throughout the study at 500 ppm. The Agency has classified lambda-cyhalothrin as a Group D carcinogen (not classifiable due to an equivocal finding in this study). It is Zeneca's position that no treatment-related carcinogenic effects were observed under the conditions of the study. 6. Animal metabolism. Metabolism studies in rats demonstrated that distribution patterns and excretion rates in multiple oral dose studies are similar to single-dose studies. Accumulation of unchanged compound in fat upon chronic administration shows slow elimination. Otherwise, lambda-cyhalothrin was rapidly metabolized and excreted. The metabolism of [[Page 50366]] lambda-cyhalothrin in livestock has been studied in the goat, chicken, and cow. Unchanged lambda-cyhalothrin is the major residue component of toxicological concern in meat and milk. Human metabolism of lambda-cyhalothrin was assessed by administering 5 mg lambda-cyhalothrin orally to six male volunteers (average dose was 0.06 mg/kg) and dermally at 20 mg/800 cm2 to five volunteers. No adverse effects were noted in the individuals given an oral dose, and only mild signs of parasthesia were noted in individuals receiving a dermal dose. Absorption by these two routes of exposure were determined by analysis of urinary metabolites. An average amount of 59% of the oral dose was absorbed. Dermal absorption was extremely low, and estimated to be 0.12% (range 0.04-0.19%). 7. Metabolite toxicology. The Agency has previously determined that the metabolites of lambda-cyhalothrin are not of toxicological concern and need not be included in the tolerance expression. Given this determination, it is concluded that there is no need to discuss metabolite toxicity. 8. Endocrine disruption. EPA is required to develop a screening program to determine whether certain substances (including all pesticides and inerts) ``may have an effect in humans that is similar to an effect produced by a naturally occurring estrogen, or such other endocrine effect***.'' The Agency is currently working with interested stakeholders, including other government agencies, public interest groups, industry and research scientists in developing a screening and testing program and a priority setting scheme to implement this program. Congress has allowed 3 years from the passage of FQPA (August 3, 1999) to implement this program. At that time, EPA may require further testing of this active ingredient and end use products for endocrine disrupter effects. C. Aggregate Exposure Zeneca has conducted an aggregate exposure assessment for lambda- cyhalothrin. This assessment included exposures resulting from agricultural crop use and non-dietary residential use. 1. Dietary exposure. For the purposes of assessing the potential chronic dietary exposure for all existing and pending tolerances for lambda-cyhalothrin, Zeneca has utilized available information on anticipated residues (FDA monitoring data, average field trial residues and processing data) and percent crop treated. For the acute dietary assessment, a Monte Carlo modeling was used to estimate exposure. 2. Food. The Agency has stated that the acute dietary risk assessment for lambda-cyhalothrin should be based on a toxicological NOEL from a 1-year dog study. Zeneca disagrees with EPA's selection of a multiple-dose toxicological endpoint (0.5 mg/kg) for the acute dietary risk assessment, and have requested the Agency to base the acute dietary NOEL on single-dose effects. Acute risk, by EPA definition, results from 1-day consumption of food and water, and reflects toxicity which could be expressed following a single oral exposure to pesticide residues. Therefore, an appropriate NOEL must be based on effects noted after a single dose, even if the endpoint is selected from a repeat dose study, such as a 1-year dog. Nonetheless, sufficient margins of exposure are achieved at percentiles of exposure up to and including the 99.9th percentile based on the Agency's NOEL of 0.5 mg/kg. Based on the Agency's selected acute toxicity endpoint of 0.5 mg/kg bw day, the acute dietary MOE for the most highly exposed population subgroup was children 1-6 years old. The MOEs were 658 at the 95th percentile, 248 at the 99th percentile, and 132 at the 99.9th percentile. EPA concludes that there is a reasonable certainty of no harm for a MOE of 100 or greater. Therefore, the acute dietary risk assessment for lambda-cyhalothrin clearly indicates a reasonable certainty of no harm. The assessment of chronic dietary exposure was estimated to be 5.0% of the chronic reference dose (RfD) for the overall U.S. population. The RfD for lambda-cyhalothrin, 0.001 mg/kg bw /day, is based on the NOEL of 0.1 mg/kg from the 1-year dog study and an Uncertainty Factor of 100. For the most exposed subgroup, children 1-6 years old, the exposure was estimated to be 0.000159 mg/kg bw/day, or 15.9% of the RfD. Since EPA generally has no concern for exposures below 100 percent of the RfD, there is a reasonable certainty that no harm will result from chronic dietary exposure to lambda-cyhalothrin residues. 3. Drinking water. Laboratory and field data have demonstrated that lambda-cyhalothrin and its degradates are immobile in soil and will not leach into ground water. Other data show that lambda-cyhalothrin is virtually insoluble in water and extremely lipophilic. As a result, residues reaching surface waters from field runoff will quickly adsorb to sediment particles and be partitioned from the water column. Together these data indicate that residues are not expected in drinking water. A screening evaluation of leaching potential of a typical pyrethroid was conducted using EPA's Pesticide Root Zone Model (PRZM3). Based on this screening assessment, the potential concentrations of a pyrethorid in ground water at depths of 1 and 2 meters are essentially zero (< 0.001 parts per billion (ppb)). Surface water concentrations for pyrethroids were estimated using PRZM3 and Exposure Analysis Modeling System (EXAMS) using standard EPA cotton runoff and Mississippi pond scenarios. The maximum concentration predicted in the simulated pond was 0.052 ppb. Concentrations in actual drinking water would be much lower than the levels predicted in the hypothetical, small, stagnant farm pond model since drinking water derived from surface water would normally be treated before consumption. Based on these analyses, the contribution of water to the dietary risk estimate is negligible. 4. Non-dietary exposure. Other potential sources of exposure are from non-occupational sources such as structural pest control and ornamental plant and lawn use of lambda-cyhalothrin. In its review of toxicity endpoints for assessing risks for lambda-cyhalothrin, the Agency concluded that the most appropriate endpoint for non-dietary risk assessment is 10 mg/kg bw/day based on the NOEL from the 21-day dermal toxicity study. Exposure was estimated using available market use information and surrogate indoor exposure data. The resulting MOEs were 15,000 for the U.S. population, 7,000 for non-nursing infants and 7,200 for children 1-6 years old. The aggregate risk assessment of combined exposures from chronic dietary, drinking water and non-dietary residential sources has been conducted. The resulting MOEs are 14,000 for the U.S. Population, 6,500 for non-nursing infants and 6,500 for children 1-6 years old. EPA concludes that there is a reasonable certainty of no harm for MOE of 100 or greater. Therefore, the non- dietary and overall aggregate risk assessments for lambda-cyhalothrin clearly indicates a reasonable certainty of no harm. D. Cumulative Effects Zeneca Ag Products will submit information for EPA to consider concerning potential cumulative effects of lambda-cyhalothrin consistent with the schedule established by EPA at 62 FR 42020 (August 4, 1997)(FRL-5734-6) and other EPA publications pursuant to the FQPA. At this time, Zeneca cannot make a determination based on [[Page 50367]] available and reliable information that lambda-cyhalothrin and other substances that may have a common mechanism of toxicity would have cumulative effects. Therefore for purposes of this request it is appropriate only to consider the potential risks of lambda-cyhalothrin in an aggregate exposure assessment. E. Safety Determination The acceptable RfD based on a NOEL of 0.1 mg/kg bw/day from the chronic dog study and a safety factor of 100 is 0.001 mg/kg bw/day. A chronic dietary exposure/risk assessment has been performed for lambda- cyhalothrin using the above RfD. Available information on anticipated residues, monitoring data and percent crop treated was incorporated into the analysis to estimate the Anticipated Residue Contribution (ARC). The ARC is generally considered a more realistic estimate than an estimate based on tolerance level residues. 1. U.S. population. The ARC from established tolerances and the current and pending actions are estimated to be 0.00005 mg/kg bw/day and utilize 5.0 per cent of the RfD for the U.S. population. For the acute dietary assessment the MOEs at the 95th, 99th, and 99.9th percentiles are 2074, 742, and 237, respectively. 2. Infants and children. FFDCA 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. EPA generally defines the level of appreciable risk as exposure that is greater than 1/100 of the NOEL in the animal study appropriate to the particular risk assessment. This hundredfold uncertainty (safety) factor/margin of exposure is designed to account for combined inter and intraspecies variability. EPA believes that reliable data support using the standard hundredfold margin/factor and not the additional tenfold margin/factor when EPA has a complete database under existing guidelines and when the severity of the effect in infants and children or the potency or unusual toxic properties of a compound do not raise concerns regarding the adequacy of the standard margin/factor. In assessing the potential for additional sensitivity of infants and children to residues of lambda-cyhalothrin, EPA considered the data from oral developmental toxicity studies in the rat and rabbit, as well as data from a multi-generation reproduction study in the rat. The developmental toxicity studies are designed to evaluate adverse effects in the developing organism resulting from pesticide exposure during prenatal development in the mothers. Reproduction studies provide information relating to effects from exposure to the pesticide on the reproductive capability of mating animals and data on systemic toxicity. i. Pre-natal effects. A developmental toxicity study in rats given gavage doses of 0, 5, 10, and 15 mg/kg/day with no developmental toxicity observed under the conditions of the study. The developmental NOEL is greater than 15 mg/kg/day, the highest dose tested. The maternal NOEL and LOEL are established at 10 and 15 mg/kg/day, respectively, based on reduced body weight gain. A developmental toxicity study in rabbits given gavage doses of 0, 3, 10, and 30 mg/kg/day with no developmental toxicity observed under the conditions of the study. The maternal NOEL and LOEL are established at 10 and 30 mg/kg/day, respectively based on decreased body weight gain. The developmental NOEL is greater than 30 mg/kg/day, the highest dose tested. ii. Post-natal effects. A three-generation reproduction study in rats fed diets containing 0, 10, 30, and 100 ppm with no developmental toxicity observed at 100 ppm, the highest dose tested. The maternal NOEL and LOEL for the study are established at 30 (1.5 mg/kg/day) and 100 ppm (5 mg/kg/day), respectively, based upon decreased parental body weight gain. The reproductive NOEL and LOEL are established at 30 (1.5 mg/kg/day) and 100 ppm (5 mg/kg/day), respectively, based on decreased pup weight gain during weaning. In EPA's review of the toxicity endpoints for lambda-cyhalothrin they concluded that the data on developmental and reproductive toxicity tests do not indicate any increased pre- or post-natal sensitivity. Therefore, EPA concluded that reliable data support use of a hundredfold safety factor and that an additional tenfold safety factor is not needed. Based on this information the ARC for children 1-6 years old, and non-nursing infants (subgroups most highly exposed) utilizes 0.000159 mg/kg bw/day (15.9% of the RfD) and 0.000101 mg/kg bw/day (10.1% of the RfD), respectively. Generally speaking, the Agency has no cause for concern if anticipated residues contribution for all published and proposed tolerances is less than the RfD. For the acute dietary assessment the MOEs at the 95th, 99th, and 99.9th percentiles are 658, 248, and 132, respectively for children 1-6 years old. For non-nursing infants the MOEs at the 95th, 99th and 99.9th percentiles are 710, 316, and 152, respectively. F. International Tolerances There are Codex maximum residue levels established for residues of cyhalothrin, as the sum of all isomers, in or on the following crops and commodities: pome fruits at 0.2 ppm; cabbage, head at 0.2 ppm; potatoes at 0.02 ppm; cotton seed at 0.02 ppm; cotton seed oil, crude at 0.02 ppm; and cotton seed oil, edible at 0.02 ppm. (Adam Heyward) [FR Doc. 97-25499 Filed 9-22-97; 3:06 pm] BILLING CODE 6560-50-F