Pesticides; tolerances in food, animal feeds, and raw agricultural commodities: Sethoxydim,
[Federal Register: October 8, 1998 (Volume 63, Number 195)]
[Rules and Regulations]
[Page 54066-54073]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr08oc98-11]
ENVIRONMENTAL PROTECTION AGENCY
[OPP-300739; FRL-6034-1]
RIN 2070-AB78
Sethoxydim; Pesticide Tolerance
AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule.
SUMMARY: This regulation establishes a tolerance for combined residues of sethoxydim (2-[1-(ethoxyimino]butyl)-5-[2-(ethylthio)propyl]-3- hydroxy-2-cyclohexen-1-one) and its metabolites containing the 2- cyclohexen-1-one moiety(calculated as the herbicide) in or on apricots, cherries (sweet and sour), nectarines, peaches, succulent beans, bean forage, soybeans, grapes, raisins, cilantro, leafy vegetable (except Brassica) crop group, tuberous and corm vegetable subgroup, garden beets, caneberry crop sub group, and globe artichoke. This regulation also deletes the established tolerances for raisin waste, grape pomace, celery, head lettuce, leaf lettuce, spinach, endive(escarole), potato, sweet potato, and raspberry. BASF Corporation and Interregional Research Project Number (IR-4) requested these tolerances under the Federal Food, Drug and Cosmetic Act (FFDCA), as amended by the Food Quality Protection Act of 1996 (Pub. L. 104-170).
DATES: This regulation is effective October 8, 1998. Objections and requests for hearings must be received by EPA on or before December 7, 1998.
ADDRESSES: Written objections and hearing requests, identified by the docket control number, [OPP-300739], must be submitted to: Hearing Clerk (1900), Environmental Protection Agency, Rm. M3708, 401 M St., SW., Washington, DC 20460. Fees accompanying objections and hearing requests shall be labeled ``Tolerance Petition Fees'' and forwarded to: EPA Headquarters Accounting Operations Branch, OPP (Tolerance Fees), P.O. Box 360277M, Pittsburgh, PA 15251. A copy of any objections and hearing requests filedwith the Hearing Clerk identified by the docket control number, [OPP-300739], must also be submitted to: Public Information and Records Integrity Branch, Information Resources and Services Division (7502C), Office of Pesticide Programs, Environmental Protection Agency, 401 M St., SW., Washington, DC 20460. In person, bring a copy of objections and hearing requests to Rm. 119, Crystal Mall #2, 1921 Jefferson Davis Hwy., Arlington, VA.
A copy of objections and hearing requests filedwith the Hearing Clerk may also be submitted electronically by sending electronic mail (e-mail) to: opp-docket@epamail.epa.gov. Copies of objections and hearing requests must be submitted as an ASCII file avoiding the use of special characters and any form of encryption. Copies of objections and hearing requests will also be accepted on disks in WordPerfect 5.1/6.1 file format or ASCII file format. All copies of objections and hearing requests in electronic form must be identified by the docket control number [OPP-300739]. No Confidential Business Information (CBI) should be submitted through e-mail. Electronic copies of objections and hearing requests on this rule may be filedonline at many Federal Depository Libraries.
FOR FURTHER INFORMATION CONTACT: By mail: Jim Tompkins or Hoyt Jamerson, Registration Division [7505C], Office of Pesticide Programs, Environmental Protection Agency, 401 M St., SW., Washington, DC 20460. Office location, telephone number, and e-mail address: Crystal Mall #2, 1921 Jefferson Davis Hwy., Arlington, VA, Jim Tompkins (703) 305 5697, Hoyt Jamerson (703) 308 9368, e-mail: Tompkins.jim or Jamerson,hoyt]@epamail.epa.gov.
SUPPLEMENTARY INFORMATION: In the Federal Register of May 16, 1997 (62 FR 27028)(FRL-5717-6) and August 5, 1998(63 FR 41829)(FRL-5799-6), EPA issued a notice pursuant to section 408 of the Federal Food, Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 346a(e) announcing the filing of a pesticide petition (PP) for tolerance by BASF Corporation, P.O. Box 13528, Research Triangle Park, NC 27709, and Interregional Research Project Number 4 (IR-4), New Jersey Agricultural Experimental Station, Rutgers University, New Brunswick, New Jersey 08903. These notices included a summary of the petitions prepared by BASF Corporation, the registrants, and IR-4. There were no comments received in response to the notice of filing.
The petition requested that 40 CFR 180.412 be amended by establishing tolerances for combined residues of the herbicide sethoxydim (2-[1-ethoxyimino]butyl]-5-[2-(ethylthio)propyl]-3-hydroxy- 2-cyclohexen-1-one and its metabolites containing the 2-cyclohexen moiety (calculated as the herbicide), in or on 9F3408 (62 FR 27028) apricots at 0.2 part per million (ppm), cherries (sweet and sour) at 0.2 ppm, nectarine at 0.2 ppm, and peaches at 0.2 ppm; 6F4695 (63 FR 41829) grapes at 1.0 ppm, succulent beans at 15.0 ppm; bean forage at 15.0 ppm, soybeans at 16.0 ppm, and raisins at 2.0 ppm; 6E4953 (63 FR 41829) leafy vegetable (except Brassica) crop group at 4.0 ppm and cilantro at 4.0 ppm; 6E4725 (63 FR 41829)--tuberous and corm vegetable subgroup at 4.0 ppm and garden beet at 1.0 ppm; 6E4698 (63 FR 41829) artichokes at 5.0 ppm; and 6E4697(63 FR 41829) caneberry crop subgroup at 5.0 ppm.
The notice issued August 5, 1998 (63 FR 41829) for 6F4695 proposed deleting the established tolerances for raisin waste at 1.0 ppm and grape pomace at 6.0 ppm since they are considered insignificant animal feed commodities and are no longer of regulatory concern.
The August 5, 1998 notice also proposed to remove or delete the established tolerances for celery at 1.0 ppm, head lettuce at 1.0 ppm, leaf lettuce at 2.0 ppm, spinach at 4.0 ppm, endive(escarole) at 2.0 ppm (6E4753); potato at 4.0 ppm, and sweet potato at
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4.0 ppm (6E4725); and raspberry at 5.0 ppm (6E4797) since these commodities are members of the crop groups or subgroups for which tolerances are being established.
The correct terminology for artichoke is globe artichoke. The Agency is correcting the terminology in this rule.
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Risk Assessment and Statutory Findings
Section 408(b)(2)(A)(i) of the 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) 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) 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....''
EPA performs a number of analyses to determine the risks from aggregate exposure to pesticide residues. For further discussion of the regulatory requirements of section 408 and a complete description of the risk assessment process, see the Final Rule on Bifenthrin Pesticide Tolerances (62 FR 62961, November 26, 1997) (FRL-5754-7).
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Aggregate Risk Assessment and Determination of Safety
Consistent with 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 sethoxydim and to make a determination on aggregate exposure, consistent with section 408(b)(2), for a tolerance for combined residues of 2-[1-ethoxyimino)butyl]-5-[2-(ethiothio)propyl]-3-hydroxy- 2-cyclohexen-1-one and its metabolites containing the 2-cyclohexen-1- one moiety(calculated as the herbicide) on [apricots at 0.2 ppm, cherries (sweet and sour) at 0.2 ppm, nectarines at 0.2 ppm, peaches at 0.2 ppm, grapes at 1.0 ppm, succulent beans at 15.0 ppm, bean forage at 15.0 ppm, soybeans at 16.0 ppm, raisins at 2.0 ppm, leafy vegetable (except Brassica) crop group at 4.0 ppm., cilantro at 4.0 ppm, tuberous and corm vegetable subgroup at 4.0 ppm, garden beet at 1.0 ppm, globe artichoke at 5.0 ppm, and caneberry crop subgroup at 5.0 ppm. ppm. EPA's assessment of the dietary exposures and risks associated with establishing the tolerance 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. The nature of the toxic effects caused by sethoxydim are discussed below.
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Acute toxicity. Based on the available acute toxicity data, sethoxydim does not pose any acute dietary risks. A summary of the acute toxicity studies follows.
i. Acute oral toxicity, rat. Toxicity Category III; LD‹INF›50‹/INF›=3,125 millgrams/kilogram (mg/kg) (male), 2,676 mg/kg (female)
ii. Acute dermal toxicity, rat. Toxicity Category III; LD‹INF›50‹/INF› › 5,000 mg/kg (male and female)
iii. Acute inhalation toxicity, rat. Toxicity Category III; LC‹INF›50‹/INF› (4-hour)=6.03 mg/L (male), 6.28 mg/L (female)
iv. Primary eye irritation, rabbit. Toxicity Category IV; no irritation.
v. Primary dermal irritation, rabbit. Toxicity Category IV; no irritation.
vi. Dermal sensitization, guinea pig. Waived because no sensitization was seen in guinea pigs dosed with the end-use product Poast (18% active ingredient).
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Genotoxicity. Ames assays were negative for gene mutation in Salmonella typhimurium strains TA98, TA100, TA1535, and TA 1537, with and without metabolic activity. A Chinese hamster bone marrow cytogenetic assay was negative for structural chromosomal aberrations at doses up to 5,000 mg/kg in Chinese hamster bone marrow cells in vivo. Recombinant assays and forward mutations tests in Bacillus subtilis, Escherichia coli, and S. typhimurium were all negative for genotoxic effects at concentrations of greater than or equal to 100%.
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Reproductive and developmental toxicity. A 2-generation reproduction study with rats fed diets containing 0, 150, 600, and 3,000 ppm (approximately 0, 7.5, 30, and 150 mg/kg/day) with no reproductive effects observed under the conditions of the study.
A developmental toxicity study in rats fed dosages of 0, 50, 180, 650, and 1,000 mg/kg/day with a maternal NOAEL of 180 mg/kg/day and a maternal LEL of 650 mg/kg/day (irregular gait, decreased activity, excessive salivation, and anogenital staining); and a developmental NOAEL of 180 mg/kg/day, and a developmental LEL of 650 mg/kg/day (21 to 22% decrease in fetal weights, filamentous tail, and lack of tail due to the absence of sacral and/or caudal vertebrae, and delayed ossification in the hyoids, vertebral centrum and/or transverse processes, sternebrae and/or metatarsal, and pubes).
A developmental toxicity study in rabbits fed doses of 0, 80, 160, 320, and 400 mg/kg/day with a maternal NOAEL of 320 mg/kg/day and a maternal LOEL of 400 mg/kg/day (37% reduction in body weight gain without significant differences in group mean body weights and decreased food consumption during dosing); and a developmental NOAEL greater than 400 mg/kg/day (highest dose tested).
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Subchronic toxicity. A 21-day dermal study in rabbits with a No- Observed-Adverse-Effect-Level (NOAEL) of › 1,000 mg/kg/day (limit dose). The only dose-related finding was slight epidermal hyperplasia at the dosing site in nearly all males and females dosed at 1,000 mg/ kg/day. This was probably an adaptive response.
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Chronic toxicity. A 1-year feeding study with dogs fed diets containing 0, 8.86/9.41, 17.5/19.9, and 110/129 mg/kg/day (males/ females) with a No-Observed-Adverse-Effect-Level (NOAEL) of 8.86/9.41 mg/kg/day (males/females) based on equivocal anemia in male dogs at the 17.5-mg/kg/day dose level.
A 2-year chronic feeding/carcinogenicity study with mice fed diets containing 0, 40, 120, 360, and 1,080 ppm (equivalent to 0, 6, 18, 54, and 162 mg/kg/day) with a systemic NOAEL of 120 ppm (18 mg/kg/day) based on non-neoplastic liver lesions in male mice at the 360-ppm (54 mg/kg/day) dose level. There were no carcinogenic effects observed under the conditions of the study. The maximum tolerated dose (MTD) was not achieved in female mice. The need for a new study will be based on the adequacy of the rat study currently under review.
A 2-year chronic feeding/carcinogenic study with rats fed diets containing 0, 2, 6, and 18 mg/kg/day with a systemic NOAEL greater than or equal to 18 mg/kg/day (highest dose tested). There were no carcinogenic
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effects observed under the conditions of the study. This study was reviewed under current guidelines and was found to be unacceptable because the doses used were insufficient to induce a toxic response and an MTD was not achieved. A second chronic feeding/carcinogenic study with rats fed diets containing 0, 360, and 1,080 ppm (equivalent to 18.2/23.0, and 55.9/ 71.8 mg/kg/day (males/females). The dose levels were too low to elicit a toxic response in the test animals and failed to achieve an MTD or define a lowest effect level (LEL). Slight decreases in body weight in rats at the 1,080-ppm dose level, although not biologically significant, support a free-standing NOAEL of 1,080 ppm (55.9/71.8 mg/ kg/day (males/females)). There were no carcinogenic effects observed under the conditions of the study.
A third chronic feeding/carcinogenicity study has been submitted. Male and female rats were dosed at nominal concentrations of 0, 300, 1,000, and 3,000 ppm. Clinical findings at the high-dose included changes in food consumption, food efficiency, and body weight; and liver pathology. Upon initial review, it appears that the dose selection was adequate, and that there was no evidence of carcinogenicity. 6. Animal metabolism. In a rat metabolism study, excretion was extremely rapid and tissue accumulation was negligible.
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Toxicological Endpoints
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Acute toxicity. In a rat developmental study rats received doses of 0, 50, 180, 650, and 1,000 mg/kg/day. The maternal toxicity NOAEL was 180 mg/kg/day and the LOEL was 650 mg/kg/day based on irregular gait, decreased activity, excessive salivation, and ano-genital staining. For developmental toxicity the NOAEL was 180 mg/kg/day and the LOEL was 650 mg/kg/day based on 21-22% decrease in fetal weights, filamentous tail and lack of tail due to the absence of accral and/or caudal vertebrae, and delayed oss ification in the hyoids, vertebral centrum and/or transverse processes, sternebrae and/or metatarsal, and pubes. The endpoint for use in the risk assessment is the maternal NOAEL of 180 mg/kg/day. The endpoint is set on maternal effects because the NOAEL for developmental effects is also 180 mg/kg/day. 2. Short- and intermediate-term toxicity. No short or intermediate dermal or inhalation endpoints were identified. In a 21-day dermal study with rabbits dosed at 0, 40, 200, and 1,000 mg/kg/day, there was no evidence of compound related toxicity on clinical signs, body weights, food consumption, food efficiency, eye health, clinical pathology, organ weights, or gross pathology. The NOAEL was greater than 1,000 mg/kg/day (limit dose). In the acute inhalation study with rats the LC‹INF›50‹/INF› was 6.03 mg/l (males) and 6.28 mg/l (females placing sethoxydim in Category IV. 3. Chronic toxicity. EPA has established the Reference dose (RfD) for sethoxydim at 0.09 mg/kg/day. This RfD is based on a finding of equivocal anemia in the 1-year dog study. The NOAEL was 8.86 mg/kg in males and 9.41 mg/kg in females.
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Carcinogenicity. Sethoxydim is not classified. Avialable studies show no evidence of carcinogenicity in rats or mice.
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Exposures and Risks
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From food and feed uses. Tolerances have been established (40 CFR 180.412) for the combined residues of 2-[1-(ethoxyimino]butyl)-5-
[2-(ethylthio)propyl] -3-hydroxy-2-cyclohexen-1-one and its metabolites containing the 2-cyclohexen-1-one moiety (calculated as the herbicide), in or on a variety of raw agricultural commodities. Tolerances are established on cattle, goats, horses, and sheep meat, fat, and meat by products at 0.2 ppm, eggs at 2.0 ppm, poultry meat and fat at 0.2 ppm and poultry meat by products at 2.0 ppm. Risk assessments were conducted by EPA to assessed dietary exposures from sethoxydim as follows:
i. Acute exposure and risk. Acute dietary 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. The acute dietary endpoint is 180 mg/kg/ day based on NOAELs of 180 mg/kg/day for maternal and developmental effects in the rabbit developmental study. The FQPA safety factor of 3x was applied to females 13+ years old only because the endpoint (based on decrease in fetal weights, filamentous tail and lack of tail due to absence of sacral and/or caudal vertebrae, delayed ossification in the hyoids, vertebral centrum and/or transverse processes, sternebrae and/ or metatarsal) occurs only during in utero exposure and is not a postnatal effect. Since the effects occur during in utero exposure, it is not an appropriate endpoint for acute dietary risk assessment of infants and children.
In conducting this acute dietary risk assessment, the Agency made very conservative assumptions 100% of all commodities having sethoxydim tolerances will contain sethoxydim regulable residues and those residues will be at the level of the tolerance which result in an over estimation of human dietary exposure.
From the acute dietary (food only) risk assessment, a high-end exposure estimate of 0.2 mg/kg/day was calculated. This exposure yielded dietary (food only) MOEs ranging from 420 for childern (1-6 years old) to 622 for female 13+ years old and greater than 500 for all other subgroups.
ii. Chronic exposure and risk. The FQPA Safety Factor will not be applied for chronic dietary risk assessment because the endpoint is based on anemia in male dogs. The endpoint for which the FQPA safety factor is based is an in utero effect and can not result from postnatal exposure. There was no indication of increased susceptibility in the prenatal developmental study in rabbits following in utero exposure. In the 2-generation reproduction study in rats, effects in offspring were observed only at above treatment levels which resulted in evidence of appreciable parental toxicity. No incresed susceptibility was demonstrated in the developmental toxicity study with rats when the maternal and developmnetal NOAEL/LOELs were compared.
In conducting this chronic dietary risk assessment, The Agency has made very conservative assumptions no percent crop-treated data were used and all commodities having sethoxydim tolerances will contain sethoxydim residues ans those residues will be at the level of the tolerance which will result in an overestimate of human dietary exposure.
The sethoxydim tolerances (published and pending) result in a Theoretical Maximum Residue Contribution (TMRC) that is equivalent to the following percentages of the RfD:
Percent Subgroup
TMRC RFD
U.S. Population.................................... 0.039187
44 Nursing Infants.................................... 0.018957
21 Non-Nursing Infants (‹ 1 year old)................. 0.072949
81 Children (1-6 years old)........................... 0.085308
95 Children (7-12 years old).......................... 0.058101
65 Female (13+, nursing).............................. 0.040144
45 Males (13-19 years old)............................ 0.040429
45 U.S Population (Summer Season)..................... 0.039408
44 Hispanics.......................................... 0.039428
44 Non-Hispanic Others................................ 0.040452
45 Non-Hispanic Whites................................ 0.039238
44
The subgroups listed above are (1) the U.S. population (48 states); (2) those for infants, children, females, 13+ nursing;
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and other subgroups for which the percentage of RfD occupied is greater than occupied by the subgroup U.S. population
iii. Chronic, carcinogenic risk. Sethoxydim has not been classified. At the present time, studies do not show evidence of carcinogenitcy in rats or mice.
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From drinking water. Limited monitoring data of ground water and surface water are available for sethoxydim. The modeling data found maximun concentrations in ground wate of 0.84 micrograms/liter (‹greek-m›g/L) and in surface water 59.4 ‹greek-m›g/L and 56-day EECs of 37.3 ‹greek-m›g/L. The modeling data were compared to the results of the following equations used to calculate acute and chronic drinking water level of concern (DWLOC) for sethoxydim in ground and surface water (SOP for Drinking Water Exposure and Risk Assessments, 11/20/97). Models used were SCI-GROW and GENEC to provide estimates of ground and surface water contamination respectively from sethoxydim, but did not consider the behavior of degradates. Agency default weights and water consumption used in the calculations were 70kg(2L) for adult males, 60 kg(2L) for adult females, and 10 kg (1L) for child.
i. Acute exposure and risk. Based on acute dietary exposure and using default body weights and water consumption values stated above, acute DWLOC were calculated using the following equation. DWLOC (acute)=(NOAEL divided by uncertainty factor)- (Acute food + residential exposure(mg/kg/day) x (body weight)divided by consumption(L) x 10‹SUP›-3‹/SUP› mg/‹greek-m›g
Acute dietary water levels of concern were calculated to be 525,000 ‹greek-m›g/L for the U.S. population, 56,000 ‹greek-m›g/L for adult males 13+ years old, 12,000 ‹greek-m›g/L for adult females 13+ years old (including 3x safety factor) and 14,000 ‹greek-m›g/L for child ( infant ‹ 1 year old).
ii. Chronic exposure and risk. Based on chronic dietary (food) exposure and using default body weights and water consumption values above the chronic DWLOC for drinking water were calculated using the following equation:
DWLOC (chronic) = RfD - (chronic food + residential exposure (mg/kg/day 0 x (body weight) divided by consumption (L) x 105-3 mg/ ‹greek-m›g
Chronic DWLOCs were calculated to be 1,760 ‹greek-m›g/L for the U.S. population, 1,780 ‹greek-m›g/L for adult males 13-19 years old, 1,700 for adult female 13+ years old, nursing and 135 for child (1-6 years old).
The above calculations indicate that the exposure to sethoxydim in drinking water using the modeling data are below the calculated drinking water level of concern for all populations.
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From non-dietary exposure. sethoxydim is currently registered for use on the following residential non-food sites: ornamentals and flowering plants, recreational areas, and buildings/structures (non- agricultural-outdoor). These residential uses compromise a short- and intermediate-term exposure scenario, but does not comprise a chronic exposure scenario.
i. Acute exposure and risk. There is a potential for exposure to sethoxydim by homeowner mixers/applicators. However, since endpoints for dermal or inhalation were selected, therefore the use on residential non-food sites is not expected to pose an unaccpetable acute risk.
ii. Chronic exposure and risk. The registered uses for sethoxydim do not comprise a chronic exposure scenario. A chronic non-dietary endpoint was not selected, therefore the use on residental non-food sites is not expected to pose an unacceptable chronic risk.
iii. Short- and intermediate-term exposure and risk. Short term or intermediate term endpoints were not identified. However, the following scenarios may result if herbicides containing sethoxydim are applied to residential turf, and/or ornamental plants: incidental non-dietary ingestion of residues on lawns from hand-to-mouth transfer, ingestion of pesticide-treated turfgrass, and incidental ingestion of soil from treated lawns. A residential exposure estimate and risk assessment was co#nducted for post application exposure following the application of sethoxydim on turf and ornamental gardens. The acute dietary endpoint was used for this risk assessment because the acute dietary endpoint provides the worst case estimate of risk and exposure for these use patterns. The assessment was performed using Draft SOPs for Residential Exposure Assessments (12/18/98). The proposed post-application aggregate exposure assessment takes into account chronic dietary exposure plus outdoor residential exposures. These exposure assessments assume that 20 % of the application rated is available from the turf grass as dislodgeable residue and 2 hours as the duration of exposure. These assumptions are considered conservative and protective.
Exposures and margins of exposures ( MOEs) were calculated to be 0.053 mg/kg/day (MOE of 3,400) for hand-to-mouth transfer for treated lawns (toddlers), 0.0012 mg/kg/day (MOE of 150,000 ) for ingestion of treated turf grass (toddler), and 0.000025 (MOE of 7 million) for incidental ingestion of soil (toddlers). MOEs exceeded 100 for all three scenarios. MOEs greater or equal to 100 do not exceed the Agencys level of concern.
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Cumulative exposure to substances with common mechanism of toxicity. Section 408(b)(2)(D)(v) 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 does not have, at this time, available data to determine whether sethoxydim 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, sethoxydim 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 sethoxydim has 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 the Final Rule for Bifenthrin Pesticide Tolerances (62 FR 62961, November 26, 1997).
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Aggregate Risks and Determination of Safety for U.S. Population
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Acute risk. Using the published and pending tolerances, the dietary (food only) acute MOEs range from 420 for childern (1-6 years old) to 622 tor females 13+ years old. The level of concern for females 13 + years old is 300 for acute sethoxydim exposure (3X safety factor) and 100 for all other population subgroups. This risk estimate should be viewed as highly conservative; refinement using anticipated residue values and percent crop treated data in conjunction with Monte Carlo analysis will result in a lower acute dietary exposure estimate. The dietary exposure does not exceed the Agency's level of concern.
Sethoxydim is a non persistent, but highly mobile compound in soil and water environments. The modeling data for sethoxydim in drinking water indicate levels less than OPP`s DWLOC for acute exposure. Since a refined acute risk for food only would not exceed EPAs levles of concern for acute dietary exposures and the monitoring and modeling levels in water are less than the acute DWLOC, EPA does not expect
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aggregate acute exposure to sethoxydim will pose an unacceptable risk to human health.
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Chronic risk. Using the TMRC exposure assumptions described in this preamble, EPA has concluded that aggregate exposure to sethoxydim from food will utilize 44% of the RfD for the U.S. population. The major identifiable subgroup with the highest aggregate exposure is 95% for childern 1-6 years old; discussed below. EPA generally has no concern 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 sethoxydim in drinking water and from non- dietary, non-occupational exposure, EPA does not expect the aggregate exposure to exceed 100% of the RfD. EPA concludes that there is a reasonable certainty that no harm will result from aggregate exposure to sethoxydim residues.
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Short- and intermediate-term risk. Short- and intermediate-term aggregate exposure takes into account chronic dietary food and water (considered to be a background exposure level) plus indoor and outdoor residential exposure. Endpoints for short- or intermediate-term were not selected. An aggregate exposure estimate and risk assessment was conducted for post-application exposure to sethoxydim on turf and ornamental plants taking into account chronic exposure form food and the acute dietary NOAEL. The resulting MOEs (1,390-2,350) are not of concern to the Agency.
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Aggregate cancer risk for U.S. population. Sethoxydim has not been classified. Available studies do not show evidence of carcinogenicity in rats or mice.
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Determination of safety. Based on these risk assessments, EPA concludes that there is a reasonable certainty that no harm will result from aggregate exposure to sethoxydim residues.
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Aggregate Risks and Determination of Safety for Infants and Children
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Safety factor for infants and children-- i. In general. In assessing the potential for additional sensitivity of infants and children to residues of sethoxydim, EPA considered data from developmental toxicity studies in the rat and rabbit and a 2-generation reproduction study in the rat. The developmental toxicity studies are designed to evaluate adverse effects on the developing organism resulting from maternal pesticide exposure and gestation. 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 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 data base unless EPA determines that a different margin of safety will be safe for infants and children. Margins of safety are incorporated into EPA risk assessments either directly through use of a margin of exposure (MOE) analysis or through using uncertainty (safety) factors in calculating a dose level that poses no appreciable risk to humans. EPA believes that reliable data support using the standard uncertainty factor (usually 100 for combined inter- and intra-species variability)) and not the additional tenfold MOE/ uncertainty factor when EPA has a complete data base under existing guidelines and when the severity of the effect in infants or children or the potency or unusual toxic properties of a compound do not raise concerns regarding the adequacy of the standard MOE/safety factor.
ii. Pre- and post-natal sensitivity. There was no indication of increased susceptibility in the prenatal developmental toxicity study in rabbits following in utero exposure. In the 2-generation reproduction study in rats, effects in the offspring were observed only at or above treatment levels which resulted in evidence of appreciable parental toxicity. No increased susceptibility was demonstrated in the developmental toxicity study with rats when the maternal and developmental NOAELs/LOELs were compared; developmental toxic effects, however, were observed at the highest dose tested (LOEL).
Acceptable developmental toxicity studies have been performed in rats and rabbits; an acceptable 2-generaton reproduction study has also been performed in rats. A chronic feeding/carcinogenicity guideline study in rats has been submitted and is currently undergoing review. An initial examination of the study supports the current findings of no evidence of carcinogenicity. There is a complete toxicity data base for sethoxydim and exposure data is complete or is estimated based on data that reasonaby accounts for potential exposures.
The FQPA safety factor is to be retianed in case of developmental toxicity in the absence of maternal toxicity. Since malformations were seen in the rat study at levels that produced minimal maternal toxicity, the Agency concluded that an FQPA factor is needed. However, it was determined that the 10X factor need not be retained, instead should be reduced to 3X based on the following weight of evidence considerations:
a. Developmental toxicity was seen in only one species, in the presence of maternal toxicity, and at a very high dose (650 mg/kg/day) that approached the Limit-Dose of 1,000 mg/kg/day.
b. No developmental toxicity was observed in the rabbit study at the highest dose tested (400 mg/kg/day).
c. There was no increased susceptibility seen in the 2-generation reproduction study in rats at doses up to 150 mg/kg/day(highest dose tested).
d. Lack of concern for structure activity relationship (i.e. no significant developmental or reproductive toxicity was seen with the structural analog, Clethodim.) Exposure assessments do not indicate a concern for potential risk to infants and children based on; (1) the dietary exposure assessments use field study data and assume 100% crop treated which results in an overestimate of dietary exposure; (2) limited monitoring data is used for ground and surface source drinking water exposure assessments, resulting in estimates considered to be reasonable upper-bound concentrations; (3) there is a potential for post-application hand-to- mouth exposure to toddlers associated with lawn use, however, the use of conservative models and/or assumptions in the residential exposure assessment provide adequate protection of infants and children.
The FQPA safety factor is applicable for acute dietary risk assessment for females 13+ years old because the endpoint occurs only during in utero exposure and is not a postnatal effect. Since the effects occur during in utero exposure, it is not an appropriate endpoint for acute dietary risk assessment of infants and children. The FQPA safety factor is not applied for chronic risk assessment because the endpoint is an in utero effect and can not result from postnatal exposure. The FQPA safety factor is not applicable to the post- application hand-to-mouth exposure associated with the lawn use since this exposure scenario would only be expected for toddlers and not for females 13+ years old.
iii. Conclusion. Acceptable developmental toxicity studies have been performed in rats and rabbits; an acceptable 2-generation reproduction study has also been performed in rats. A chronic feeding/ carcinogenicity guideline study in rats has been submitted and is currently undergoing review. An initial examination of the
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study supports the current findings of no evidence of carcinogenicity. There is a complete toxicity data base for sethoxydim and exposure data is complete or is estimated based on data that reasonably accounts for potential exposures.
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Acute risk. Using the conservative exposure assumptions that 100% of the commodities having sethoxydim tolerances will contain sethoxydim regulable residues and that those residues will be at the level of the tolerance, EPA calculated from the acute dietary (food only) MOEs ranging from 420 for childern (1-6 years old) to 622 for females 13+ years old. The level of concern is 300 (3x safety factor x 100 ) for females 13+ years old and 100 for all other subgroups.
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Chronic risk. Using the exposure assumptions described above, EPA has concluded that aggregate exposure to sethoxydim from food will utilize 21% for nursing infants, 81% for non-nursing infants (‹ 1 years old), 95% for children (1-6 years old), and 65 % for children (7-12 years old) of the RfD. EPA generally has no concern 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 sethoxydim in drinking water and from non-dietary, non-occupational exposure, EPA does not expect the aggregate exposure to exceed 100% of the RfD.
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Short- or intermediate-term risk. An aggregate exposure estimate and risk assessment was conducted for post-application exposure to sethoxydim on turf and ornamental plants taking into account chronic exposure from food and the acute dietary NOAEL. The resulting MOEs (1,390-2,350) are not of concern to EPA.
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Determination of safety. Based on these risk assessments, EPA concludes that there is a reasonable certainty that no harm will result to infants and children from aggregate exposure to sethoxydim residues.
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Other Considerations
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Metabolism in Plants and Animals
In the rat metabolism study, tissue accumulation was neglible and excretion was extremely rapid. Elimination was 78.5% in the urine and 20.2% in the feces.
The metabolism of sethoxydim in plants and animals is understood, The tolerances for plant and animal commodities are expressed as the combined residues of sethoxydim and its metabolites containing the 2- cyclohexen-1-one moiety (calculated as the herbicide).
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Analytical Enforcement Methodology
BASF Method 30 as published in PAM,Vol II is adequate for tolerance enforcement in all raw agricultural commodities. Quantitation is accomplished by gas chromatography with flame photometric detection in the sulfur mode. sethoxydim and its metabolites are not recovered or not likely to be recovered by FDA multi-residue methods.
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Magnitude of Residues
The available crop field trial data support the establishment of tolerances in globe artichoke at 5.0 ppm; apricots at 0.2 ppm; beans, forage at 15.0 ppm; beans, succulent at 15.0 ppm; beets, garden at 1.0 ppm; caneberries, crop subgroup at 5.0 ppm; cherries (sweet and sour) at 0.2 ppm; cilantro at 4.0 ppm; grapes at 1.0 ppm; leafy vegetable (except Brassica) at 4.0 ppm; nectarines at 0.2 ppm; peaches at 0.2 ppm; raisins at 2.0 ppm; soybeans at 16.0 ppm; and tuberous and corm vegetables at 4.0 ppm.
The available data support the deletion of the established tolerances for grape pomace (wet and dry at 6.0 ppm and raisin waste at 1.0 ppm because they are considered insignificant animal feed commodities and are no longer of regulatory concern.
The available data support deletion of the existing tolerances for celery at 1.0 ppm; lettuce, leaf at 1.0 ppm; lettuce, leaf at 2.0 ppm; spinach at 4.0 ppm; endive at 2.0 ppm; potato at 4.0 ppm; sweet potato at 4.0 ppm; and raspberry at 5.0 ppm; since these commodities are members of crop groups or subgroups for which tolerances are being established.
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International Residue Limits
There are no Codex maximum Residue Levels (MRLs) in effect for sethoxydim. However, there are Canadian MRLs based on the cyclohex-1- one moiety calculated as sethoxydim: beans, peas, soybeans, and lentils at 0.5. 0.5, 5.0 and 4.0 ppm, respectively. There are also Mexican MRLs based on sethoxydim: grapes, soybeans, lettuce, potatoes, celery, lentils, spinach, beans, and peas(green) at 1.0, 10.0, 1.0, 4.0, 1.0, 30.0, 4.0, 20.0, and 10.0 ppm, respectively. The Canadian tolerances on various legume vegetables are significantly less than needed to cover residues in the United States. Many of the Mexican MRLs are the same as the United States. EPA is increasing the grape tolerance to 1.0 ppm to match Mexico`s MRL.
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Rotational Crop Restrictions
Tolerances on rotational crops are not necessary for crops planted greater than 30 days after the primary crop is treated with sethoxydim.
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Conclusion
Therefore, tolerances are established for combined residues of 2-
[1-(ethoxyimino)butyl] -5-[2-(ethylthio)propyl]-3-hydroxy-2-cyclohexen- 1-one and its metabolites containing the 2-cyclohexen-1-one moiety (calculated as the herbicide) in apricot at 0.2 ppm; globe artichoke at 5.0 ppm; beans, forage at 15.0 ppm; bean, succulent at 15.0 ppm; beet, garden at 1.0 ppm; caneberries crop subgroup at 5.0 ppm; cherries (sweet and sour) at 0.2 ppm; cilantro at 4.0 ppm; grapes at 1.0 ppm; leafy vegetable (except Brassica) at 4.0 ppm; nectarines at 0.2 ppm; peaches at 0.2 ppm; raisin at 2.0 ppm; soybean at 16.0 ppm; and tuberous and corm vegetable crop subgroup at 4.0 ppm. The current listing for artichoke is being corrected to read as globe artichoke to reflect current terminology. Established tolerances for celery at 1.0 ppm; endive at 2.0 ppm; grape pomace (wet and dry) at 6.0 ppm; lettuce, head at 1.0 ppm; lettuce, leaf at 2.0 ppm; potato at 4.0; raisin waste at 1.0 ppm; raspberry at 6.0 ppm; spinach at 4.0 ppm; and sweet potato at 4.0 ppm are being revoked.
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Objections and Hearing Requests
The new FFDCA section 408(g) provides essentially the same process for persons to ``object'' to a tolerance regulation issued by EPA under new section 408(e) and (l)(6) as was provided in the old section 408 and in section 409. However, the period for filing objections is 60 days, rather than 30 days. EPA currently has procedural regulations which govern the submission of objections and hearing requests. These regulations will require some modification to reflect the new law. However, until those modifications can be made, EPA will continue to use those procedural regulations with appropriate adjustments to reflect the new law.
Any person may, by December 7, 1998, file written objections to any aspect of this regulation and may also request a hearing on those objections. Objections and hearing requests must be filedwith the Hearing Clerk, at the address given above (40 CFR 178.20). A copy of the objections and/or hearing requests filedwith the Hearing Clerk should be submitted to the OPP docket for this rulemaking. The objections submitted must specify the provisions
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of the regulation deemed objectionable and the grounds for the objections (40 CFR 178.25). Each objection must be accompanied by the fee or a request for a fee wavier as prescribed by 40 CFR 180.33. If a hearing is requested, the objections must include a statement of the factual issues on which a hearing is requested, the requestor's contentions on such issues, and a summary of any evidence relied upon by the requestor (40 CFR 178.27). A request for a hearing will be granted if the Administrator determines that the material submitted shows the following: There is genuine and substantial issue of fact; there is a reasonable possibility that available evidence identified by the requestor would, if established, resolve one or more of such issues in favor of the requestor, taking into account uncontested claims or facts to the contrary; and resolution of the factual issues in the manner sought by the requestor would be adequate to justify the action requested (40 CFR 178.32). Information submitted in connection with an objection or hearing request may be claimed confidential by marking any part or all of that information as Confidential Business Information (CBI). Information so marked will not be disclosed except in accordance with procedures set forth in 40 CFR part 2. A copy of the information 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.
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Public Record and Electronic Submissions
EPA has established a record for this rulemaking under docket control number [OPP-300739] (including any comments and data submitted electronically). 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 public record is located in Room 119 of the Public Information and Records Integrity Branch, Information Resources and Services Division (7502C), Office of Pesticide Programs, Environmental Protection Agency, Crystal Mall #2, 1921 Jefferson Davis Highway, Arlington, VA.
Electronic comments may 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.
The official record for this rulemaking, as well as the public version, as described above will be kept in paper form. Accordingly, EPA will transfer any copies of objections and hearing requests received electronically into printed, paper form as they are received and will place the paper copies in the official rulemaking record which will also include all comments submitted directly in writing. The official rulemaking record is the paper record maintained at the Virginia address in ``ADDRESSES'' at the beginning of this document.
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Regulatory Assessment Requirements
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Certain Acts and Executive Orders
This final rule establishes tolerances under FFDCA section 408(d) in response to a petition submitted to the Agency. The Office of Management and Budget (OMB) has exempted these types of actions from review under Executive Order 12866, entitled Regulatory Planning and Review (58 FR 51735, October 4, 1993). This final rule does not contain any information collections subject to OMB approval under the Paperwork Reduction Act (PRA), 44 U.S.C. 3501 et seq., or impose any enforceable duty or contain any unfunded mandate as described under Title II of the Unfunded Mandates Reform Act of 1995 (UMRA) (Pub. L. 104-4). Nor does it require any prior consultation as specified by Executive Order 12875, entitled Enhancing the Intergovernmental Partnership (58 FR 58093, October 28, 1993), or special considerations as required by Executive Order 12898, entitled Federal Actions to Address Environmental Justice in Minority Populations and Low-Income Populations (59 FR 7629, February 16, 1994), or require OMB review in accordance with Executive Order 13045, entitled Protection of Children from Environmental Health Risks and Safety Risks (62 FR 19885, April 23, 1997).
In addition, since tolerances and exemptions that are established on the basis of a petition under FFDCA section 408(d), such as the tolerances in this final rule, do not require the issuance of a proposed rule, the requirements of the Regulatory Flexibility Act (RFA) (5 U.S.C. 601 et seq.) do not apply. Nevertheless, the Agency has previously assessed whether establishing tolerances, exemptions from tolerances, raising tolerance levels or expanding exemptions might adversely impact small entities and concluded, as a generic matter, that there is no adverse economic impact. The factual basis for the Agency's generic certification for tolerance actions published on May 4, 1981 (46 FR 24950) and was provided to the Chief Counsel for Advocacy of the Small Business Administration.
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Executive Order 12875
Under Executive Order 12875, entitled Enhancing the Intergovernmental Partnership (58 FR 58093, October 28, 1993), EPA may not issue a regulation that is not required by statute and that creates a mandate upon a State, local, or tribal government, unless the Federal government provides the funds necessary to pay the direct compliance costs incurred by those governments. If the mandate is unfunded, EPA must provide to OMB a description of the extent of EPA's prior consultation with representatives of affected State, local, and tribal governments, the nature of their concerns, copies of any written communications from the governments, and a statement supporting the need to issue the regulation. In addition, Executive Order 12875 requires EPA to develop an effective process permitting elected officials and other representatives of State, local, and tribal governments ``to provide meaningful and timely input in the development of regulatory proposals containing significant unfunded mandates.''
Today's rule does not create an unfunded Federal mandate on State, local, or tribal governments. The rule does not impose any enforceable duties on these entities. Accordingly, the requirements of section 1(a) of Executive Order 12875 do not apply to this rule.
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Executive Order 13084
Under Executive Order 13084, entitled Consultation and Coordination with Indian Tribal Governments (63 FR 27655, May 19,1998), EPA may not issue a regulation that is not required by statute, that significantly or uniquely affects the communities of Indian tribal governments, and that imposes substantial direct compliance costs on those communities, unless the Federal government provides the funds necessary to pay the direct compliance costs incurred by the tribal governments. If the mandate is unfunded, EPA must provide to OMB, in a separately identified section of the preamble to the rule, a description of the extent of EPA's prior consultation with representatives of affected tribal governments, a summary of the nature of their concerns, and a statement supporting the need to issue the regulation. In addition, Executive Order 13084 requires EPA to develop an effective process permitting elected
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officials and other representatives of Indian tribal governments ``to provide meaningful and timely input in the development of regulatory policies on matters that significantly or uniquely affect their communities.''
Today's rule does not significantly or uniquely affect the communities of Indian tribal governments. This action does not involve or impose any requirements that affect Indian tribes. Accordingly, the requirements of section 3(b) of Executive Order 13084 do not apply to this rule.
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Submission to Congress and the Comptroller General
The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the Small Business Regulatory Enforcement Fairness Act of 1996, generally provides that before a rule may take effect, the agency promulgating the rule must submit a rule report, which includes a copy of the rule, to each House of the Congress and to the Comptroller General of the United States. EPA will submit a report containing this rule and other required information to the U.S. Senate, the U.S. House of Representatives, and the Comptroller General of the United States prior to publication of the rule in the Federal Register. This rule is not a ``major rule'' as defined by 5 U.S.C. 804(2).
List of Subjects in 40 CFR Part 180
Environmental protection, Administrative practice and procedure, Agricultural commodities, Pesticides and pests, Reporting and recordkeeping requirements.
Dated: September 29, 1998.
James Jones,
Director, Registration Division, Office of Pesticide Programs.
Therefore, 40 CFR chapter I is amended as follows:
PART 180-- AMENDED]
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The authority citation for part 180 continues to read as follows:
Authority: 21 U.S.C. 346a and 371.
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Section 180.412 is amended as follows:
a. In the table to paragraph (a):
i. By removing the entries for celery; grape pomace (wet and dry); lettuce, head; lettuce, leaf; potatoes; raisin waste; raspberries; spinach; and sweet potato.
ii. By revising the entries for beans, forage; beans, succulent; grapes; raisins; and soybeans.
iii. By adding entries for apricots; beet, garden; caneberries crop subgroup; cherries (sweet and sour); cilantro; leafy vegetable (except Brassica) crop group; nectarines; peaches; and tuberous and corm vegetables crop subgroup.
b. In the table to paragraph (c) by removing the entry for endive, and by revising the entry for artichokes.
The added and revised portions read as follows:
Sec. 180.412 Sethoxydim; tolerances for residues.
(a) General. ***
Parts Expiration/ Commodity
Per Revocation Million date
* * * * * Apricots.......................................... 0.2
None * * * * * Beans, forage.................................... 15.0
None Beans, succulent.................................. 15.0
None Beet, garden...................................... 1.0
None * * * * * Caneberries crop subgroup......................... 5.0
None * * * * * Cherries (sweet and sour)......................... 0.2
None Cilantro.......................................... 4.0
None * * * * * Grapes............................................ 1.0
None * * * * * Leafy vegetable (except Brassica) crop group...... 4.0
None * * * * * Nectarines........................................ 0.2
None Peaches........................................... 0.2
None * * * * * Raisins........................................... 2.0
None * * * * * Soybeans.......................................... 16.0
None * * * * * Tuberous and corm vegetable crop subgroup......... 4.0
None
* * * * *
(c) Tolerances with regional registrations. ***
Parts Expiration/ Commodity
Per Revocation Million date
Globe artichoke................................... 5.0
None * * * * *
* * * * *
FR Doc. 98-26905Filed10-7-98; 8:45 am] BILLING CODE 6560-50-F
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