Fludioxonil; Pesticide Tolerances
Federal Register, Volume 77 Issue 158 (Wednesday, August 15, 2012)
Federal Register Volume 77, Number 158 (Wednesday, August 15, 2012)
Rules and Regulations
Pages 48907-48915
From the Federal Register Online via the Government Printing Office www.gpo.gov
FR Doc No: 2012-19988
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ENVIRONMENTAL PROTECTION AGENCY
EPA-HQ-OPP-2011-0395; FRL-9357-5
Fludioxonil; Pesticide Tolerances
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
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SUMMARY: This regulation establishes tolerances for residues of fludioxonil in or on multiple commodities which are identified and discussed later in this document, associated with pesticide petition (PP) 1E7853 and PP 1E7870. This regulation additionally revises several established tolerances, and removes several established permanent and time-limited tolerances. Interregional Research Project Number 4 (IR-4) and Syngenta Crop Protection, LLC, requested the tolerances associated with PP 1E7853 and PP 1E7870, respectively, under the Federal Food, Drug, and Cosmetic Act (FFDCA).
DATES: This regulation is effective August 15, 2012. Objections and requests for hearings must be received on or before October 15, 2012, and must be filed in accordance with the instructions provided in 40 CFR part 178 (see also Unit I.C. of the SUPPLEMENTARY INFORMATION).
ADDRESSES: The docket for this action, identified by docket identification (ID) number EPA-HQ-OPP-2011-0395, is available either electronically through http://www.regulations.gov or in hard copy at the OPP Docket in the Environmental Protection Agency Docket Center (EPA/DC), located in EPA West, Rm. 3334, 1301 Constitution Ave. NW., Washington, DC 20460-0001. The Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. The telephone number for the Public Reading Room is (202) 566-1744, and the telephone number for the OPP Docket is (703) 305-5805. Please review the visitor instructions and additional information about the docket available at http://www.epa.gov/dockets.
FOR FURTHER INFORMATION CONTACT: Laura Nollen, Registration Division (7505P), Office of Pesticide Programs, Environmental Protection Agency, 1200 Pennsylvania Ave. NW., Washington, DC 20460-0001; telephone number: (703) 305-7390; email address: nollen.laura@epa.gov.
SUPPLEMENTARY INFORMATION:
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General Information
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Does this Action apply to me?
You may be potentially affected by this action if you are an agricultural producer, food manufacturer, or pesticide manufacturer. Potentially affected entities may include, but are not limited to those engaged in the following activities:
Crop production (NAICS code 111).
Animal production (NAICS code 112).
Food manufacturing (NAICS code 311).
Pesticide manufacturing (NAICS code 32532).
This listing is not intended to be exhaustive, but rather to provide a guide for readers regarding entities likely to be affected by this action. Other types of entities not listed in this unit could also be affected. The North American Industrial Classification System (NAICS) codes have been provided to assist you and others in determining whether this action might apply to certain entities. If you have any questions regarding the applicability of this action to a particular entity, consult the person listed under FOR FURTHER INFORMATION CONTACT.
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How can I get electronic access to other related information?
You may access a frequently updated electronic version of EPA's tolerance regulations at 40 CFR part 180 through the Government Printing Office's e-CFR site at http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?&c=ecfr&tpl=/ecfrbrowse/Title40/40tab_02.tpl.
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How can I file an objection or hearing request?
Under FFDCA section 408(g), 21 U.S.C. 346a, any person may file an objection to any aspect of this regulation and may also request a hearing on those objections. You must file your objection or request a hearing on this regulation in accordance with the instructions provided in 40 CFR part 178. To ensure proper receipt by EPA, you must identify docket ID number EPA-HQ-OPP-2011-0395 in the subject line on the first page of your submission. All objections and requests for a hearing must be in writing, and must be received by the Hearing Clerk on or before October 15, 2012. Addresses for mail and hand delivery of objections and hearing requests are provided in 40 CFR 178.25(b).
In addition to filing an objection or hearing request with the Hearing Clerk as described in 40 CFR part 178, please submit a copy of the filing that does not contain any CBI for inclusion in the public docket. Information not marked confidential pursuant to 40 CFR part 2 may be disclosed publicly by EPA without prior notice. Submit a copy of your non-CBI objection or hearing request, identified by docket ID number EPA-HQ-OPP-2011-0395, by one of the following methods:
ADDRESSES: Submit your comments, identified by docket identification (ID) number EPA-HQ-OPP-2011-0395 by one of the following methods:
Federal eRulemaking Portal: http://www.regulations.gov. Follow the online instructions for submitting comments. Do not submit electronically any information you consider to be Confidential Business Information (CBI) or other information whose disclosure is restricted by statute.
Mail: OPP Docket, Environmental Protection Agency Docket Center (EPA/DC), Mail Code: 28221T, 1200 Pennsylvania Ave. NW., Washington, DC 20460-0001.
Hand Delivery: To make special arrangements for hand delivery or delivery of boxed information, please follow the instructions at http://www.epa.gov/dockets/contacts.htm.
Additional instructions on commenting or visiting the docket, along with more information about dockets generally, is available at http://www.epa.gov/dockets.
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Summary of Petitioned-For Tolerances
In the Federal Register of July 20, 2011 (76 FR 43231) (FRL-8880-
1), EPA issued a notice pursuant to FFDCA section 408(d)(3), 21 U.S.C. 346a(d)(3), announcing the filing of a pesticide petition, PP 1E7853, by IR-4, 500 College Road East, Suite 201W, Princeton, NJ 08540. The petition requested that 40 CFR 180.516 be amended by establishing tolerances for residues of the fungicide fludioxonil, (4-(2,2-difluoro-
1,3-benzodioxol-4-yl)-1-H -pyrrole-3-carbonitrile), in or on acerola at 5.0 parts per million (ppm); atemoya at 20 ppm; biriba at 20 ppm; cherimoya at 20 ppm; custard apple at 20 ppm; feijoa at 5.0 ppm; guava at 5.0 ppm; ilama at 20 ppm; jaboticaba at 5.0 ppm; passionfruit at 5.0 ppm; soursop at 20 ppm; starfruit at 5.0 ppm; sugar apple at
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20 ppm; wax jambu at 5.0 ppm; ginseng at 3.0 ppm; onion, bulb subgroup 3-07A at 0.2 ppm; onion, green subgroup 3-07B at 7.0 ppm; caneberry subgroup 13-07A at 5.0 ppm; bushberry subgroup 13-07B at 2.0 ppm; fruit, small vine climbing, except fuzzy kiwifruit, subgroup 13-07F at 1.0 ppm; berry, low growing, subgroup 13-07G, except cranberry at 2.0 ppm; vegetable, fruiting, group 8-10, except tomato at 0.7 ppm; fruit, citrus, group 10-10 at 10 ppm; fruit, pome, group 11-10 at 5.0 ppm; leafy greens subgroup 4A at 30 ppm; potato at 6.0 ppm; pineapple at 8.0 ppm; and dragon fruit at 1.0 ppm.
That notice additionally requested to amend established tolerances of fludioxonil in or on avocado from 0.45 ppm to 5.0 ppm; sapote, black from 0.45 ppm to 5.0 ppm; canistel from 0.45 ppm to 5.0 ppm; sapote, mamey from 0.45 ppm to 5.0 ppm; mango from 0.45 ppm to 5.0 ppm; papaya from 0.45 ppm to 5.0 ppm; sapodilla from 0.45 ppm to 5.0 ppm; star apple from 0.45 ppm to 5.0 ppm; longan from 1.0 ppm to 20 ppm; lychee from 1.0 ppm to 20 ppm; pulasan from 1.0 ppm to 20 ppm; rambutan from 1.0 ppm to 20 ppm; Spanish lime from 1.0 ppm to 20 ppm; and tomato from 0.50 ppm to 3.0 ppm. Upon approval of the aforementioned tolerances, the petition finally requested to amend 40 CFR 180.516 by removing the established tolerances for residues of fludioxonil in or on the following raw agricultural commodities: Onion, bulb at 0.2 ppm; onion, green at 7.0 ppm; caneberry subgroup 13A at 5.0 ppm; bushberry subgroup 13B at 2.0 ppm; Juneberry at 2.0 ppm; lingonberry at 2.0 ppm; salal at 2.0 ppm; grape at 1.0 ppm; strawberry at 2.0 ppm; vegetable, fruiting, group 8 at 0.01 ppm; tomatillo at 0.50 ppm; fruit, citrus, group 10 at 10 ppm; fruit, pome, group 11 at 5.0 ppm; and leafy greens subgroup 4A, except spinach at 30 ppm. That notice referenced a summary of the petition prepared on behalf of IR-4 by Syngenta Crop Protection, LLC, the registrant, which is available in the docket, http://www.regulations.gov. There were no comments received in response to the notice of filing.
In the Federal Register of May 2, 2012 (77 FR 25954) (FRL-9346-1), EPA issued a notice pursuant to FFDCA section 408(d)(3), 21 U.S.C. 346a(d)(3), announcing the filing of a pesticide petition (PP 1E7853) by IR-4, that requested that 40 CFR 180.516 be amended by establishing tolerances for residues of the fungicide fludioxonil, (4-(2,2-difluoro-
1,3-benzodioxol-4-yl)-1-H -pyrrole-3-carbonitrile), in or on the commodities requested in the Federal Register of July 20, 2011, with one change. This petition requested to establish a tolerance for residues of fludioxonil in or on vegetable, tuberous and corm, subgroup 1C at 6.0 ppm. This request superseded the previous request to establish a tolerance in or on potato at 6.0 ppm, as potato is the representative commodity of crop subgroup 1C. The May 2, 2012 petition additionally requested that EPA remove the established tolerance in or on vegetable, tuberous and corm, subgroup 1D at 3.5 ppm, as the tolerance will be superseded by the vegetable, tuberous and corm, subgroup 1C tolerance. That notice referenced a summary of the petition prepared on behalf of IR-4 by Syngenta Crop Protection, LLC, the registrant, which is available in the docket, http://www.regulations.gov. One comment was received to this notice of filing. EPA's response to this comment is discussed in Unit IV.C.
Additionally, in the Federal Register of April 4, 2012 (77 FR 20334) (FRL-9340-4), EPA issued a notice pursuant to FFDCA section 408(d)(3), 21 U.S.C. 346(d)(3), announcing the filing of PP 1E7870 by Syngenta Crop Protection, LLC, P.O. Box 18300, Greensboro, NC 27409. The petition requested that 40 CFR 180.516 be amended by establishing a tolerance for residues of the fungicide fludioxonil in or on leafy petioles subgroup 04B at 14 ppm. That notice referenced a summary of the petition prepared by Syngenta Crop Protection, LLC, the registrant, which is available in the docket, http://www.regulations.gov. One comment was received to this notice of filing. EPA's response to this comment is discussed in Unit IV.C.
Based upon review of the data supporting the petitions, EPA has revised the proposed tolerance levels and/or has revised the commodity definitions for several commodities. Additionally, EPA has removed several established tolerances and has determined that tolerances should be established in or on several livestock commodities. Finally, the Agency has revised the tolerance expression for all established commodities to be consistent with current Agency policy. The reasons for these changes are explained in Unit IV.D.
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Aggregate Risk Assessment and Determination of Safety
Section 408(b)(2)(A)(i) of FFDCA allows EPA to establish a tolerance (the legal limit for a pesticide chemical residue in or on a food) only if EPA determines that the tolerance is ``safe.'' Section 408(b)(2)(A)(ii) of FFDCA defines ``safe'' to mean that ``there is a reasonable certainty that no harm will result from aggregate exposure to the pesticide chemical residue, including all anticipated dietary exposures and all other exposures for which there is reliable information.'' This includes exposure through drinking water and in residential settings, but does not include occupational exposure. Section 408(b)(2)(C) of FFDCA requires EPA to give special consideration to exposure of infants and children to the pesticide chemical residue in establishing a tolerance and to ``ensure that there is a reasonable certainty that no harm will result to infants and children from aggregate exposure to the pesticide chemical residue * * *.''
Consistent with FFDCA section 408(b)(2)(D), and the factors specified in FFDCA section 408(b)(2)(D), EPA has reviewed the available scientific data and other relevant information in support of this action. EPA has sufficient data to assess the hazards of and to make a determination on aggregate exposure for fludioxonil including exposure resulting from the tolerances established by this action. EPA's assessment of exposures and risks associated with fludioxonil follows.
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Toxicological Profile
EPA has evaluated the available toxicity data and considered its validity, completeness, and reliability as well as the relationship of the results of the studies to human risk. EPA has also considered available information concerning the variability of the sensitivities of major identifiable subgroups of consumers, including infants and children.
Fludioxonil is of low acute toxicity and is not a dermal sensitizer. For subchronic and chronic toxicity, the primary effects in the mouse and rat were similar and included decreased body weight and food consumption associated with clinical pathological and histopathological effects in the liver and kidney. In the subchronic dog study, diarrhea was the most sensitive indicator of toxicity. In contrast, in the chronic toxicity study in dogs, decreased body-weight gain in females was the most sensitive indicator of toxicity. Liver toxicity was observed in both dog studies at higher doses.
Fludioxonil is not developmentally toxic in rabbits. In a rat developmental toxicity study at the highest dose tested (HDT), fludioxonil caused an increase in fetal incidence and litter incidence of dilated renal pelvis in the presence of maternal toxicity. There was no quantitative or qualitative evidence of increased susceptibility to rats and rabbits following in utero exposure. There was also no quantitative or
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qualitative evidence of increased susceptibility to rats following postnatal exposure and there was no evidence of immunotoxicity when tested up to including the limit dose.
EPA determined that fludioxonil poses a negligible cancer risk. This conclusion was based on the fact that cancer studies with fludioxonil only showed marginal evidence of cancer in one sex of one species. There was no evidence of carcinogenicity in mice when tested up to the limited dose 7,000 ppm. There was no evidence of carcinogenicity in male rats, but there was a statistically significant increase, both trend and pairwise, of combined hepatocellular tumors in female rats. The pairwise increase for combined tumors was significant at p = 0.03, which is not a strong indication of a positive effect. Further, statistical significance was only found when liver adenomas were combined with liver carcinomas. Finally, the increase in these tumors was within, but at the high end, of the historical controls. Fludioxonil was not mutagenic in the tests for gene mutations. However, based on the induction of polyploidy in the in vitro Chinese hamster ovary cell cytogenetic assay and the suggestive evidence of micronuclei induction in rat hepatocytes in vivo, additional mutagenicity testing was performed in three studies specifically designed to address the concerns regarding aneuploidy. The results of these assays were negative for aneuploidy activity.
Specific information on the studies received and the nature of the adverse effects caused by fludioxonil as well as the no-observed-
adverse-effect-level (NOAEL) and the lowest-observed-adverse-effect-
level (LOAEL) from the toxicity studies can be found at http://www.regulations.gov in document: ``Fludioxonil. Tolerance Petitions for Residues in/on Ginseng, Leafy Petioles Crop Subgroup 4B, Pineapple (post-harvest treatment), Tuberous and Corm Vegetable Subgroup 1C, Tropical Fruit (post-harvest treatment), Bulb Onion Subgroup 3-07A, Green Onion subgroup 3-07B, Caneberry Subgroup 13-07A, Bushberry Subgroup 13-07B, Small Fruit Vine Climbing Subgroup 13-07F (except fuzzy kiwifruit), Low-Growing Berry Subgroup 13-07G (except cranberry), Fruiting Vegetable Group 8-10 (except tomato), Citrus Fruit Group 10-
10, Pome Fruit Group 11-10, Leafy Vegetable (except Brassica) Subgroup 04A, Dragon Fruit, and Tomato (post-harvest treatment). Human-Health Risk Assessment.'' pp. 40-42 in docket ID number EPA-HQ-OPP-2011-0395.
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Toxicological Points of Departure/Levels of Concern
Once a pesticide's toxicological profile is determined, EPA identifies toxicological points of departure (POD) and levels of concern to use in evaluating the risk posed by human exposure to the pesticide. For hazards that have a threshold below which there is no appreciable risk, the toxicological POD is used as the basis for derivation of reference values for risk assessment. PODs are developed based on a careful analysis of the doses in each toxicological study to determine the dose at which no adverse effects are observed (the NOAEL) and the lowest dose at which adverse effects of concern are identified (the LOAEL). Uncertainty/safety factors are used in conjunction with the POD to calculate a safe exposure level--generally referred to as a population-adjusted dose (PAD) or a reference dose (RfD)--and a safe margin of exposure (MOE). For non-threshold risks, the Agency assumes that any amount of exposure will lead to some degree of risk. Thus, the Agency estimates risk in terms of the probability of an occurrence of the adverse effect expected in a lifetime. For more information on the general principles EPA uses in risk characterization and a complete description of the risk assessment process, see http://www.epa.gov/pesticides/factsheets/riskassess.htm. A summary of the toxicological endpoints for fludioxonil used for human risk assessment is shown in the Table of this unit.
Table--Summary of Toxicological Doses and Endpoints for Fludioxonil for Use in Human Health Risk Assessment
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Point of departure
Exposure/scenario and uncertainty/ RfD, PAD, LOC for Study and toxicological effects
safety factors risk assessment
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Acute dietary (Females 13-49 NOAEL = 100 mg/kg/ Acute RfD = 1 mg/kg/ Prenatal developmental toxicity in
years of age). day. day. rats
UFA = 10X........... aPAD = 1 mg/kg/day. LOAEL = 1,000 mg/kg/day based on
UFH = 10X........... the increased incidence of
FQPA SF = 1X........ fetuses and litters with dilated
renal pelvis and dilated ureter
in rat developmental study.
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Acute dietary (General population There were no appropriate toxicological effects attributable to a single
including infants and children). exposure (dose) observed in available oral toxicity studies, including
maternal toxicity in the developmental toxicity studies. Therefore, a dose
and endpoint were not identified for this risk assessment.
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Chronic dietary (All populations) NOAEL= 3.3 mg/kg/day Chronic RfD = 0.033 Chronic toxicity in dogs
UFA = 10X........... mg/kg/day. LOAEL = 35.5 mg/kg/day based on
UFH = 10X........... cPAD = 0.033 mg/kg/ decreased weight gain in female
FQPA SF = 1X........ day. dogs during weeks 1-52 of one-
year dog feeding study.
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Incidental oral short-term (1 to NOAEL= 10 mg/kg/day. LOC for MOE = 100.. Rabbit developmental study
30 days). UFA = 10X........... LOAEL = 100 mg/kg/day based on
UFH = 10X........... decreased weight gain during
FQPA SF = 1X........ dosing period.
Incidental oral intermediate-term NOAEL= 3.3 mg/kg/day LOC for MOE = 100.. Chronic toxicity in dogs
(1 to 6 months). UFA= 10X............ LOAEL = 35.5 mg/kg/day based on
UFH= 10X............ decreased weight gain in female
FQPA SF = 1X........ dogs during weeks 1-52 of one-
year dog feeding study.
Inhalation short-term (1 to 30 Inhalation (or oral) LOC for MOE = 1000. Rabbit developmental study
days). study NOAEL = 10 mg/ LOAEL = 100 mg/kg/day based on
kg/day (inhalation decreased weight gain during
absorption rate = dosing period.
100%).
UFA = 10X...........
UFH = 10X...........
FQPA SF = 10X.......
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Cancer (Oral, dermal, inhalation) Poses no greater than a negligible cancer risk.
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FQPA SF = Food Quality Protection Act Safety Factor. LOAEL = lowest-observed-adverse-effect-level. LOC = level
of concern. mg/kg/day = milligram/kilogram/day. MOE = margin of exposure. NOAEL = no-observed-adverse-effect-
level. PAD = population adjusted dose (a = acute, c = chronic). RfD = reference dose. UF = uncertainty factor.
UFA = extrapolation from animal to human (interspecies). UFDB = to account for the absence of data or other
data deficiency. UFH = potential variation in sensitivity among members of the human population
(intraspecies).
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Exposure Assessment
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Dietary exposure from food and feed uses. In evaluating dietary exposure to fludioxonil, EPA considered exposure under the petitioned-
for tolerances as well as all existing fludioxonil tolerances in 40 CFR 180.516. EPA assessed dietary exposures from fludioxonil in food as follows:
i. Acute exposure. Quantitative acute dietary exposure and 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. Such effects were identified for fludioxonil for females 13-49 years old (i.e., females of child-
bearing age). In estimating acute dietary exposure, EPA used food consumption information from the United States Department of Agriculture (USDA) 1994-1996 and 1998 Nationwide Continuing Surveys of Food Intake by Individuals (CSFII). As to residue levels in food, EPA assumed tolerance-level residues, 100 percent crop treated (PCT) estimates, and DEEMTM ver. 7.81 default processing factors. There were no appropriate toxicological effects attributable to a single exposure for the general population; therefore, these population subgroups were not included in this assessment.
ii. Chronic exposure. In conducting the chronic dietary exposure assessment EPA used the food consumption data from the USDA 1994-1996 and 1998 CSFII. As to residue levels in food, EPA assumed tolerance-
level residues for most commodities, with the exception of the following commodities for which anticipated residues were used: Celery, pineapple, potato, spinach, apple, grapefruit, lemon, lime, orange, pear, tomato, head lettuce, leaf lettuce, fresh parsley, brassica leafy vegetables group 5, grape, cherry, peach, and plum. The anticipated residues were estimated from field trial and processing study data for the chronic analysis. The chronic dietary exposure assessment also incorporated 100 PCT estimates and DEEMTM ver. 7.81 default processing factors, with the exception of citrus fruit juice (1X), apple juice (1X), grape juice (0.42X), raisin (1.65X), potato commodities (1X), and tomato commodities (1X), except dried tomato (14.3X). These processing factors are based upon crop-specific processing study data.
iii. Cancer. Based on the data summarized in Unit III.A., EPA has concluded that fludioxonil poses a negligible cancer risk to humans. Therefore, a dietary exposure assessment for the purpose of assessing cancer risk is unnecessary.
iv. Anticipated residue information. Section 408(b)(2)(E) of FFDCA authorizes EPA to use available data and information on the anticipated residue levels of pesticide residues in food and the actual levels of pesticide residues that have been measured in food. If EPA relies on such information, EPA must require pursuant to FFDCA section 408(f)(1) that data be provided 5 years after the tolerance is established, modified, or left in effect, demonstrating that the levels in food are not above the levels anticipated. For the present action, EPA will issue such data call-ins as are required by FFDCA section 408(b)(2)(E) and authorized under FFDCA section 408(f)(1). Data will be required to be submitted no later than 5 years from the date of issuance of these tolerances.
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Dietary exposure from drinking water. The Agency used screening level water exposure models in the dietary exposure analysis and risk assessment for fludioxonil in drinking water. These simulation models take into account data on the physical, chemical, and fate/transport characteristics of fludioxonil. Further information regarding EPA drinking water models used in pesticide exposure assessment can be found at http://www.epa.gov/oppefed1/models/water/index.htm.
Based on the Pesticide Root Zone Model/Exposure Analysis Modeling System (PRZM/EXAMS) and Screening Concentration in Ground Water (SCI-
GROW) models, the estimated drinking water concentrations (EDWCs) of fludioxonil for surface water are expected to be 83.8 parts per billion (ppb) for acute exposures and 38.5 ppb for chronic exposures. The EDWCs of fludioxonil for ground water are expected to be 0.2 ppb for acute and chronic exposures.
Modeled estimates of drinking water concentrations were directly entered into the dietary exposure model. For acute dietary risk assessment, the water concentration value of 83.8 ppb was used to assess the contribution to drinking water. For chronic dietary risk assessment, the water concentration of value 38.5 ppb was used to assess the contribution to drinking water.
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From non-dietary exposure. The term ``residential exposure'' is used in this document to refer to non-occupational, non-dietary exposure (e.g., for lawn and garden pest control, indoor pest control, termiticides, and flea and tick control on pets). Fludioxonil is currently registered for the following uses that could result in residential exposures: Parks, golf courses, athletic fields, residential lawns, ornamentals, and greenhouses. In addition to the conventional uses of fludioxonil in residential areas, there are also antimicrobial uses. However, residential turf uses of fludioxonil are expected to result in the highest potential exposure of all registered residential uses of fludioxonil and, therefore, were assessed.
EPA assessed residential exposure using the following assumptions: Short-term inhalation for residential handler exposure scenarios, including mixing/loading/applying fludioxonil. Residential handler exposures were considered to be short-term only due to the infrequent use patterns associated with homeowner products. Additionally, EPA assessed potential short- and intermediate-term postapplication exposures to toddlers (children 1-2 years old) resulting from physical activities on turf. These included incidental oral exposures from hand-
to-mouth, object-to-mouth, and incidental soil ingestion. Further information regarding EPA standard assumptions and generic inputs for residential exposures may be found at http://www.epa.gov/pesticides/trac/science/trac6a05.pdf.
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Cumulative effects from substances with a common mechanism of toxicity. Section 408(b)(2)(D)(v) of FFDCA requires that, when considering whether to establish, modify, or revoke a tolerance, the Agency consider ``available information'' concerning the cumulative effects of a particular pesticide's residues and ``other substances that have a common mechanism of toxicity.'' EPA has not found fludioxonil to share a common mechanism of toxicity with any other substances, and fludioxonil does not appear to produce a toxic metabolite produced by other substances. For the purposes of this tolerance action, therefore, EPA has assumed that fludioxonil does not have a common mechanism of toxicity with other substances. For information regarding EPA's efforts to determine which chemicals have a common mechanism of toxicity and to evaluate the cumulative effects of such chemicals, see EPA's Web site at http://www.epa.gov/pesticides/cumulative.
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Safety Factor for Infants and Children
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In general. Section 408(b)(2)(C) of FFDCA provides that EPA shall apply an additional tenfold (10X) margin of safety for infants and children in the case of threshold effects to account for prenatal and postnatal toxicity and the completeness of the database on toxicity and exposure unless EPA determines based on reliable data that a different margin of safety will be safe for infants and children. This additional margin of safety is commonly referred to as the FQPA Safety Factor (SF). In applying this provision, EPA either retains the default value of 10X, or uses a different additional safety factor when reliable data available to EPA support the choice of a different factor.
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Prenatal and postnatal sensitivity. The fludioxonil toxicity database includes developmental toxicity studies in rats and rabbits and a 2-generation reproduction study in rats. In the rat developmental study, there was an increase in the number of fetuses and litters with dilated renal pelvis and dilated ureter at the limit dose (1,000 mg/kg/
day); maternal toxicity occurred at the same dose and was manifested as a reduction in corrected body-weight gain, indicating that there is no quantitative susceptibility for these fetal effects. In the rabbit developmental study, no developmental toxicity was seen up to the HDT. Maternal toxicity was demonstrated at that dose. In the 2-generation rat reproduction study, offspring toxicity was seen at the same dose that produced parental toxicity. The parental toxicity was manifested as increased clinical signs, decreased body weight, body weight gain and food consumption. Offspring toxicity was manifested as decreased weight gain in pups. Parental and offspring toxicity were comparable; therefore, it was concluded that there is no increased susceptibility in the 2-generation reproduction study.
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Conclusion. EPA has determined that reliable data show the safety of infants and children would be adequately protected if the FQPA SF were reduced to 1X for risks other than those related to inhalation exposure. EPA is retaining the 10X FQPA safety factor for risks from inhalation exposure. That decision is based on the following findings:
i. The toxicity database for fludioxonil is complete except for a 90-day inhalation study. The point of departure for assessing risk from inhalation exposure is being extrapolated from an oral study. The uncertainty associated with this extrapolation requires the retention of the 10X FQPA SF for these exposures.
ii. The only potential indicator of neurotoxicity in the fludioxonil toxicity database was convulsions noted in mice following handling at high doses. The convulsions were considered to be agonal in nature. Therefore, EPA has determined that there is no need for a developmental neurotoxicity study or an additional safety factor to account for neurotoxicity.
iii. There is no evidence that fludioxonil results in increased susceptibility in in utero rabbits in the prenatal developmental study or in young rats in the 2-generation reproduction study. In the rat developmental toxicity study, fetal effects were noted at the limit dose in the presence of maternal toxicity. However, EPA determined that the degree of concern is low for the noted fetal effects because the effects were observed at the same doses as maternal effects, and there is a clear NOAEL established which was used in endpoint selection.
iv. There are no residual uncertainties identified in the exposure databases. The acute dietary assessment for females 13-49 years old was unrefined, assuming 100 PCT and tolerance-level
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residues, and the chronic dietary exposure assessment assumed 100 PCT and used tolerance-level residues or made use of average residues derived from crop field trial studies. The chronic assessment also assumed DEEM default or other processing factors based on reliable processing data. EPA made conservative (protective) assumptions in the ground and surface water modeling used to assess exposure to fludioxonil in drinking water. EPA used similarly conservative assumptions to assess short- and intermediate-term postapplication exposure resulting from incidental oral exposure of toddlers. These assessments will not underestimate the exposure and risks posed by fludioxonil.
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Aggregate Risks and Determination of Safety
EPA determines whether acute and chronic dietary pesticide exposures are safe by comparing aggregate exposure estimates to the acute PAD (aPAD) and chronic PAD (cPAD). For linear cancer risks, EPA calculates the lifetime probability of acquiring cancer given the estimated aggregate exposure. Short-, intermediate-, and chronic-term risks are evaluated by comparing the estimated aggregate food, water, and residential exposure to the appropriate PODs to ensure that an adequate MOE exists.
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Acute risk. An acute aggregate risk assessment takes into account acute exposure estimates from dietary consumption of food and drinking water. Using the exposure assumptions discussed in this unit for acute exposure, the acute dietary exposure from food and water to fludioxonil will occupy 16% of the aPAD for females 13-49 years old, the population group identified as having a potential acute exposure to fludioxonil.
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Chronic risk. Using the exposure assumptions described in this unit for chronic exposure, EPA has concluded that chronic exposure to fludioxonil from food and water will utilize 68% of the cPAD for children 1 to 2 years old, the population group receiving the greatest exposure. Based on the explanation in Unit III.C.3., regarding residential use patterns, chronic residential exposure to residues of fludioxonil is not expected.
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Short-term risk. Short-term aggregate exposure takes into account short-term residential exposure plus chronic exposure to food and water (considered to be a background exposure level). Fludioxonil is currently registered for uses that could result in short-term residential exposure, and the Agency has determined that it is appropriate to aggregate chronic exposure through food and water with short-term residential exposures to fludioxonil.
Using the exposure assumptions described in this unit for short-
term exposures, EPA has concluded the combined short-term food, water, and residential exposures result in an aggregate MOE of 310 for children 1-2 years old. Because EPA's level of concern for fludioxonil is a MOE of 100 or below, this MOE is not of concern.
Because the short-term oral and inhalation risks were estimated using the same oral POD, these routes of exposure could be combined for the adult short-term exposure assessment. However, because the level of concern for oral and inhalation routes of exposure are not the same (an MOE of
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