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Oxyfluorfen (Rohm & Haas). January 9, 1998. Pesticide Tolerance Petition. Federal Register.
http://www.epa.gov/fedrgstr/EPA-PEST/1998/January/Day-09/p557.htm
[Federal Register: January 9, 1998 (Volume 63, Number 6)] [Notices] [Page 1456-1464] From the Federal Register Online via GPO Access [wais.access.gpo.gov] [DOCID:fr09ja98-67] ----------------------------------------------------------------------- ENVIRONMENTAL PROTECTION AGENCY [PF-786; FRL-5762-6] Notice of Filing of Pesticide Petitions AGENCY: Environmental Protection Agency (EPA). [[Page 1457]] 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-786, must be received on or before February 9, 1998. ADDRESSES: By mail submit written comments to: Public Information and Records Integrity Branch (7502C), Information Resources and Services Division, 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: The product manager listed in the table below: ------------------------------------------------------------------------ Office location/ Product Manager telephone number Address ------------------------------------------------------------------------ Joanne Miller (PM 23)......... Rm. 237, CM #2, 703- 1921 Jefferson 305-6224, e-mail: Davis Hwy, miller.joanne@epamail Arlington, VA .epa.gov. Marion Johnson (PM 10)........ Rm. 217, CM #2, 703- Do. 305-6788, e-mail: johnson.marion@epamai l.epa.gov. Cynthia Giles-Parker (PM 22).. Rm. 229, CM #2, 703- Do. 305-7740, e-mail: giles- parker.cynthia@epamai l.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-786] (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 5.1/6.1 or ASCII file format. All comments and data in electronic form must be identified by the docket control number [PF-786] 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: December 17, 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. 3. Rohm & Haas Company PP 3F4229 EPA has received a pesticide petition (PP 3F4229) from Rohm & Haas Company, Philadelphia, PA, proposing pursuant to section 408(d) of the Federal Food, Drug and Cosmetic Act, 21 U.S.C. 346a(d), to amend 40 CFR part 180 by establishing a tolerance for residues of oxyfluorfen in or on the raw agricultural commodities peanut meat, meal, vine, hay, crude oil, soap stock, and refined oil at 0.05 ppm and peanut hulls at 0.10 ppm. The proposed analytical method involves extraction from the raw agricultural commodity with methanol or acetonitrite. Extracts are refluxed in presence of NaOH and Al to reduce and or hydrolyze residues to 4-(2-chloro-4-(trifluoromethyl)-phenoxy)-2-ethoxybenzenenamine. The derivatives are partitioned into hexane and heptafluorobutyryl derivatives prepared. Following Florisel cleanup, residues are determined by electron capture GLC. 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 and animal metabolism. The chemical identities of potential plant residues resulting from the use of oxyfluorfen have been elucidated. The principal residue in plants is parent oxyflurofen. The chemical identities of potential animal residues resulting from consumption of oxyfluorfen-treated crops have been elucidated. Parent oxyfluorfen is the principal residue in animal tissues. Oxyfluorfen residues do not transfer to milk (concentration <0.01 ppm at 10x dose). Residues also do not appreciably transfer to cow muscle, liver and kidney (highest level 0.011 ppm at 10x dose). Residues are present in cow fat at low levels (less than 0.01 at 1x dose). Residues in eggs and hen liver are 0.02 ppm or less on average at a 1x dose, and less than 0.01 ppm in muscle at the 1x dose. Residues approach 0.2 ppm in hen fat at the 1x dose. 2. Analytical method. There is a practical analytical method for detecting and measuring levels of oxyfluorfen in or on food with a limit of detection that allows monitoring of food with residues at or above the levels in these proposed tolerances. EPA has provided information on this method to FDA. The method is available to anyone who is interested in pesticide residue enforcement from: By mail, Calvin Furlow, Public Response and Program Resources Branch, Field Operations Division (7502C), Office of Pesticide Programs, Environmental Protection Agency, 401 M St., SW., Washington, DC 20460. Office location and telephone number: Crystal Mall #2, Rm. 1132, 1921 Jefferson Davis Highway, Arlington, Virginia, 703-305-5805. 3. Magnitude of the residues. Residue studies have been conducted in accordance with the geographic distribution mandated by the EPA for peanuts. Oxyfluorfen residues were not detectable in nutmeat [NDR <LOQ = 0.01 mg/kg] or peanut hay [NDR<LOQ = 0.03 mg/kg]. Tolerances of 0.05 ppm in [[Page 1462]] nutmeat and hay are proposed based on these data. Residues were not measured in processed fractions of peanuts and tolerances are not proposed because residues are not likely to exceed the proposed 0.05 ppm tolerance level for nutmeat since the maximum theoretical concentration factor for process fractions is 2x. B. Toxicological Profile 1. Acute toxicity. Oxyfluorfen is practically nontoxic by the oral, dermal, and respiratory routes of exposure, is nonirritating to the skin and moderately irritating to the eye. 2. Genotoxicity. In vitro tests in salmonella and mouse lymphoma cells have indicated the potential for genotoxicity. In vivo tests do not show a potential for adverse chromosal effects. 3. Reproductive and developmental toxicity. Maternal and developmental toxicity were noted at an oxyfluorfen dose of 183 mg/kg/ day (NOEL of 18 mg/kg/day) in rats and at a dose of 30 mg/kg/day (NOEL of 10 mg/kg/day) in rabbits. Reductions in body weight of offspring and histopathologic alteration of the kidneys of parents were observed with a dose of oxyfluorfen of <difference>80 mg/kg/day (NOEL <difference>20 mg/kg/ day) in a rat 2-generation reproduction study. 4. Subchronic and chronic toxicity. Adverse effects on the liver marked the LOEL in all three chronic toxicity studies with NOELs of 2.5, 2.0, and 0.3 mg/kg/day seen in the dog, rat, and mouse studies respectively. A statistically significant positive dose-related trend for liver adenomas and carcinomas was observed in the chronic mouse study and oxyfluorfen is classified as a Group C chemical by EPA. A reference dose of 0.003 mg/kg/day and a Q1<SUP>*</SUP> of 0.128 (mg/kg/ day) <SUP>-1</SUP> has been set by the Agency. 5. Animal metabolism. Animal metabolism studies have been conducted on farm animals using laying hens and lactating goats and in a laboratory animal (rat). These studies were reviewed and accepted by the Agency. EPA has concluded that the metabolism of oxyfluorfen in animals is adequately understood. C. Aggregate Exposure 1. Food. To determine chronic (using the RfD) and cancer (using the Q1<SUP>*</SUP> approach) risks, refined dietary exposure estimates using percent of crop treated and anticipated residues were utilized for registered uses of oxyfluorfen with established tolerances on the following food and/or animal feed items: dates, figs, guava, loquats, olives, papaya, persimmon, pomegranate, plantains, kiwi, cocoa butter, coffee, artichokes, taro-roots and greens, garlic, shallots, cauliflower, bok-choy, and other Chinese variety cole crops, dry beans, crabapples, quince, blackberry, raspberry, Brazil nut, cashew, chestnuts, hazelnuts, hickory nuts, macadamias, pecans, horseradish, peppermint, spearmint, pistachio nuts, cotton, cherries, nectarines, plums, prunes, almonds, walnuts, bananas, broccoli, cabbage, apricots, nutmeat, milk, onions, soybeans, apples, pears, peaches, grapes, and corn. Actual residues are expected to be quite low because the majority of the use patterns direct sprays onto weeds or soil and away from the crop. There are long preharvest intervals for sprays which are directly applied to crops. Acute dietary exposure (food only) was calculated using the TMRC (worst case) assumptions. 2. Drinking water. The Agency has reviewed environmental fate data which indicate that oxyfluorfen is persistent but nonmobile. There is no established Maximum Concentration Level (MCL) for residues of oxyfluorfen in drinking water. No health advisory levels for oxyfluorfen in drinking water have been established. As noted in ``Pesticides in Groundwater Database'' EPA 734-12-92-001, September 1992, 188 wells were monitored in Texas in 1987 and 1988. No detectable residues of oxyfluorfen were found in any of the samples. While EPA has not yet pinpointed the appropriate bounding figure for consumption of contaminated water, the ranges the Agency is continuing to examine are all below the level that would cause oxyfluorfen to exceed the RfD if the tolerance being considered in this document were granted. In addition, chronic exposure to oxyfluorfen residues resulting from potential water exposure would not increase the total cancer risk so that it exceeds the Agency's level of concern. The potential exposures associated with oxyfluorfen in water, even at the higher levels the Agency is considering as a conservative upper bound for RfD exposure considerations, would not prevent the Agency from determining that there is a reasonable certainty of no harm if the tolerance is granted. Despite the potential for acute exposure to oxyfluorfen in drinking water, it is not expected that the aggregate acute exposure will exceed the Agency's level of concern if the tolerance being considered in this document were granted. The potential acute term exposures associated with oxyfluorfen in water, even at the higher levels the Agency is considering as a conservative upper bound, would not prevent the Agency from determining that there is a reasonable certainty of no harm if the tolerance is granted. 3. Non-dietary exposure. Oxyfluorfen is registered for outdoor residential use. Acceptable, reliable data are not currently available with which to assess acute risk. However, based on the available residential exposure data and the best professional judgment of scientists who have worked with the available occupational exposure data, 5% of the risk for outdoor residential uses is a reasonable, protective default assumption for this pesticide. Chronic exposure to oxyfluorfen residues resulting from potential outdoor residential exposure would not increase the total chronic or cancer risks so that they exceed the Agency's level of concern. Theoretically, it is also possible that a residential, or other non-dietary, exposure could be combined with the acute total dietary exposure from food and water. However, the Agency does not believe that aggregating multiple exposure to large amounts of pesticide residues in the residential environment via multiple products and routes for a one- day exposure is a reasonably probable event. It is highly unlikely that, in one day, an individual would have multiple high-end exposures to the same pesticide by treating their lawn and garden, treating their house via crack and crevice application, swimming in a pool, and be maximally exposed in the food and water consumed. D. Cumulative Effects EPA does not have, at this time, available data to determine whether oxyfluorfen has a common mechanism of toxicity with other substances or how to include this pesticide in a cumulative risk assessment. Unlike other pesticides for which EPA has followed a cumulative risk approach based on a common mechanism of toxicity, oxyfluorfen does not appear to produce a toxic metabolite produced by other substances. For the purposes of this tolerance action, therefore, EPA has not assumed that oxyfluorfen has a common mechanism of toxicity with other substances. E. Endocrine Effects The toxicity studies required by EPA for the registration of pesticides measure numerous endpoints with sufficient sensitivity to detect potential endocrine-modulating activity. No effects have been identified in subchronic, chronic, reproductive, or developmental toxicity studies to indicate any endocrine-modulating activity by oxyfluorfen. [[Page 1463]] More importantly, the multi-generation reproduction study in rodents is a complex study design which measures a broad range of endpoints in the reproductive system and in developing offspring that are sensitive to alterations by chemical agents. Oxyfluorfen has been tested in two separate multi-generation studies and each time the results demonstrated that oxyfluorfen is not a reproductive toxin. F. Safety Determination 1. U.S. population-- i. Chronic RfD and cancer risk. Using the refined dietary exposure assumptions described above and taking into account the completeness and reliability of the toxicity data, it is concluded that aggregate dietary exposure (food only) to oxyfluorfen will utilize 0.04% of the RfD for the general United States population. EPA has no concern generally for exposures below 100% of the RfD because the RfD represents the level at or below which daily aggregate dietary exposure over a lifetime will not pose appreciable risks to human health. Despite the potential for exposure to oxyfluorfen in drinking water and from the 5% default-level contribution from non- dietary, nonoccupational exposure, it is not expected the aggregate exposure will exceed 100% of the RfD. As noted above, oxyfluorfen has been classified as a Group C chemical by the Agency based on liver adenomas and carcinomas in the 20-month mouse feeding study. The Agency recommends using the Q1<SUP>*</SUP> approach to assess cancer risk. A value of 0.067 (mg/kg/day)<SUP>-1</SUP> is recommended. The refined dietary assumptions for existing oxyfluorfen tolerances plus those proposed for peanuts result in an Anticipated Residue Contribution (ARC) that is equivalent to a risk of 8.0 x 10<SUP>-8</SUP> (food only). Actual residues are expected to be quite low because the majority of the use patterns direct sprays onto weeds and away from the crop and there are long preharvest intervals for sprays which are directly applied to crops. Environmental fate data indicate that oxyfluorfen strongly adheres to soil, does not leach into groundwater and has not been detected in sampled groundwater. Based on this information, occurrence of oxyfluorfen in drinking water is unlikely. Outdoor residential uses of oxyfluorfen are limited and exposure is expected to be low. Oxyfluorfen is toxic to lawn grasses and certain ornamental plants, and use is generally limited to spot treatments for nonselective weed control. Chronic exposure to oxyfluorfen residues resulting from potential residential and/or water exposure would not increase the total cancer risk so that it exceeds the Agency's level of concern. There is a reasonable certainty that no harm will result from chronic aggregate exposure to oxyfluorfen residues. ii. Acute risk. The acute dietary exposure endpoint of concern for oxyfluorfen is fused sternebrae in developing pups which was observed in the rabbit developmental study. The population subgroup of concern is females 13+ years old (women of childbearing age). For this subgroup, the calculated MOE at the high end exposure is greater than 5,000. The Agency considers dietary (food) MOEs of greater than 100 to be acceptable for oxyfluorfen. Acute dietary exposure (food only) was calculated using the TMRC (worst case) assumptions. In the absence of data for drinking water exposure, the ranges of exposure being considered by the Agency for consumption of contaminated water will be reserved for drinking water. The aggregate MOE level of concern for dietary plus the addition of upperbound estimates for drinking water is not likely to raise the MOE level of concern above 150. Despite the potential for acute exposure to oxyfluorfen in drinking water, it is not expected that the aggregate exposure will exceed the Agency's level of concern if the tolerance being considered in this document were granted. It is therefore concluded that the potential acute exposure associated with oxyfluorfen in water, even at the higher levels the Agency is considering as a conservative upper bound, would not prevent the Agency from determining that there is a reasonable certainty of no harm if the tolerance is granted. 2. Infants and Children. The toxicology database is complete for oxyfluorfen relative to prenatal and postnatal toxicity. In the developmental toxicity study in rabbits, at the maternally toxic dose of 30 mg/kg/day, there were developmental anomalies (fused sternebrae) in the fetuses which demonstrated that prenatal toxicity should be evaluated by an acute dietary risk estimate. The acute dietary MOE for pregnant women 13+ years old is greater than 5,000 based on a developmental NOEL of 10 mg/kg/day. This MOE is much higher than the minimal acceptable MOE (100 for dietary-food only) and suggests that prenatal developmental risks to infants and children from exposure to oxyfluorfen dietary residues is not a concern. Additionally, the rabbit developmental NOEL of 10 mg/kg/day is 33 times greater than the NOEL of 0.3 mg/kg/day used to calculate the RfD. In the developmental toxicity study in rats, both the developmental and maternal NOEL and LOEL of 18 and 183 mg/kg/day, respectively, occurred at the same dose levels and demonstrates that there is no special sensitivity in infants and children exposed to oxyfluorfen. Although the developmental findings in the rat were severe effects, the developmental NOEL of 18 mg/kg/day is greater than the rabbit developmental NOEL of 10 mg/kg/day used to calculate acute dietary MOEs. Therefore, the acute dietary risk estimates calculated from the rabbit developmental NOEL are lower than acute dietary MOEs which could be calculated for the more severe effects occurring in rats above the NOEL of 18 mg/kg/day. By basing the acute dietary MOEs on the NOEL in the most sensitive species (rabbit), pregnant women are protected against both types of prenatal toxicity effects as seen in the rat and rabbit developmental toxicity studies. Therefore, there are no significant prenatal toxicity concerns for infants and children due to the high MOE for pregnant women 13+ years old. In the 2-generation reproductive toxicity study in rats used to assess the postnatal toxicity potential of infants and children, the NOEL and LOEL of 20 mg/kg/day and 80 mg/kg/day, respectively, for developmental/reproductive and systemic toxicity demonstrated that there are no pup toxicity effects in the absence of parental toxicity (NOEL and LOEL are the same for pups and parental animals). Therefore, there are no special postnatal sensitivities in infants and children which can be attributed to the findings of the 2-generation reproductive toxicity study in rats. Additionally, the developmental/ reproductive NOEL of 20/mg/kg/day [which is the NOEL for decreased litter size at birth as well as decreased pup body weight] and the parental systemic NOEL of 20 mg/kg/day is 66 times greater than the NOEL of 0.3 mg/kg/day used to calculate the RfD. Based on the above, EPA concludes that reliable data support use of the standard hundredfold margin of exposure/uncertainty factor and that an additional margin/factor is not needed to protect the safety of infants and children. i. Chronic risk. Using the refined exposure assumptions described above and taking into account the completeness and reliability of the toxicity data, it is concluded that aggregate dietary exposure to oxyfluorfen will utilize 0.05% of the RfD for infants and 0.08% of the RfD for children. EPA generally has no concern for exposures below 100% of the RfD because the RfD represents the level at [[Page 1464]] or below which daily aggregate dietary exposure over a lifetime will not pose appreciable risks to human health. Despite the potential for exposure to oxyfluorfen in drinking water and from non-dietary, nonoccupational exposure, the chronic aggregate exposure is not expected to exceed 100% of the RfD. There is a reasonable certainty that no harm will result to infants and children from chronic aggregate exposure to oxyfluorfen residues. ii. Acute risk. As mentioned above, the acute dietary exposure endpoint of concern for oxyfluorfen is fused sternebrae in developing pups which was observed in the rabbit developmental study. The population subgroup of concern is females 13+ years old (women of childbearing age). For this subgroup, the calculated MOE at the high end exposure is greater than 5,000. The Agency considers dietary (food) MOEs of greater than 100 to be acceptable for oxyfluorfen. Acute dietary exposure (food only) was calculated using the TMRC (worst case) assumptions. In the absence of data for drinking water exposure, the ranges of exposure being considered by the Agency for consumption of contaminated water will be reserved for drinking water. Based on the ranges under consideration, the aggregate MOE level of concern for dietary plus the addition of drinking water is not likely to raise the MOE above the Agency's level of concern. The large MOE calculated for this use of oxyfluorfen provides assurance that there is a reasonable certainty of no harm for infants and children. G. International Tolerances There are no Codex Alimentarius Commission (CODEX) maximum residue levels (MRL's) established for residue of oxyfluorfen in or on raw agricultural commodities. (PM 23) [FR Doc. 98-557 Filed 1-8-98; 8:45 am] BILLING CODE 6560-50-F