Source: https://www.federalregister.gov/documents/2010/03/17/2010-5692/hexythiazox-pesticide-tolerances
Timestamp: 2017-09-22 12:53:31
Document Index: 17189003

Matched Legal Cases: ['art 178', 'art 180', 'art 178', 'art 178', 'art 2', '§\u2009180']

A Rule by the Environmental Protection Agency on 03/17/2010
This regulation is effective March 17, 2010. Objections and requests for hearings must be received on or before May 17, 2010, and must be filed in accordance with the instructions provided in 40 CFR part 178 (see also Unit I.C. of the SUPPLEMENTARY INFORMATION).
75 FR 12691
12691-12695 (5 pages)
FRL-8813-7
2010-5692
https://www.federalregister.gov/d/2010-5692 https://www.federalregister.gov/d/2010-5692
Start Preamble Start Printed Page 12691
This regulation revises the tolerance for combined residues of hexythiazox in or on grape. Gowan Company requested the tolerance under the Federal Food, Drug, and Cosmetic Act (FFDCA).
Olga Odiott, Registration Division (7505P), Office of Pesticide Programs, Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone number: (703) 308-9369 e-mail address: odiott.olga@epa.gov.
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 cite at http://www.gpoaccess.gov/​ecfr
Under section 408(g) of FFDCA, 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-2009-0325 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 May 17, 2010. 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 that is described in ADDRESSES. Information not marked confidential pursuant to 40 CFR part 2 may be disclosed publicly by EPA without prior notice. Submit this copy, identified by docket ID number EPA-HQ-OPP-2009-0325, by one of the following methods:
In the Federal Register of August 19, 2009 (FR 41898) (FRL-8426-7), EPA issued a notice pursuant to section 408(d)(3) of FFDCA, 21 U.S.C. 346a(d)(3), announcing the filing of a pesticide petition (PP 9F7556) by Gowan Company, 370 South Main Street; Yuma, AZ 85364. The petition requested that 40 CFR 180.448 be amended by revising the established tolerance for combined residues of the insecticide hexythiazox, (trans-5-(4-chlorophenyl)-N-cyclohexyl-4-methyl-2-oxothiazolidine-3-carboxamide) and its metabolites containing the (4-chlorophenyl)-4-methyl-2-oxo-3-thiazolidine moiety, in or on grape from 0.75 to 1.0 part per million (ppm); plum from 0.10 to 1.0 ppm; and plum, prune, dried from 0.40 to 1.0 ppm. That notice referenced a summary of the petition prepared by Gowan Company, the registrant, which is available to the public in the docket, http://www.regulations.gov. There were no comments received in response to the notice of filing.
Based upon review of the data supporting the petition, EPA has determined that there is insufficient residue chemistry data to support the proposed tolerances for the stone fruit use, therefore, this action only addresses the tolerance for grape. The Agency is also revising the tolerance expression for hexythiazox. The reason for these changes are explained in Unit IV.D.
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 Start Printed Page 12692determines 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. . . .”
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. Hexythiazox has a low order of acute toxicity by the oral, dermal and inhalation routes of exposure. It produces mild eye irritation, is not a dermal irritant, and is negative for dermal sensitization.
The target organs of hexythiazox are the liver and adrenal glands in dogs, rats and mice, with the dog being the most sensitive species. The chronic dog study showed increased liver and adrenal weights, along with associated hypertrophy of the liver and adrenal glands. The subchronic toxicity study in rats showed increased liver and adrenal weights, as well as fatty degeneration of the adrenal zona fasciculate. Effects observed in the chronic feeding/carcinogenicity studies in rats and mice included decreased body weight gain and increased liver weights.
Hexythiazox is not a developmental or reproductive toxicant. The toxicology database for hexythiazox provides no indication of increased susceptibility in rats or rabbits from in utero and postnatal exposure to hexythiazox. The database does not show any evidence of treatment-related effects on the nervous system or the immune system.
Hexythiazox is classified as “Likely to be Carcinogenic to Humans” based upon increased incidences of benign and malignant liver tumors in high-dose female mice, and benign mammary gland tumors, observed in high-dose male rats. There was no evidence of carcinogenicity in male mice and female rats. However, EPA determined that a non-quantitative risk assessment approach (i.e., nonlinear, reference dose (RfD) approach) was appropriate for hexythiazox based on the following considerations:
1. The liver tumors in mice are a very common tumor in that species were only observed in high-dose females.
2. The mammary tumors in rats were benign and were only observed in high-dose male rats.
3. Hexythiazox was shown to be non-mutagenic in mammalian somatic cells and germ cells.
Additionally, the chronic no-observed-adverse-effect-level (NOAEL) used for establishing the chronic RfD (2.5 mg/kg/day, from the 1-year toxicity feeding study in the dog), is approximately 65-fold lower than the lowest dose that induced tumors (in female mice at 163 milligrams/kilogram/day (mg/kg/day). Therefore, the chronic RfD of 0.025 mg/kg/day is judged to be protective of all chronic effects including potential carcinogenicity of hexythiazox.
Specific information on the studies received and the nature of the adverse effects caused by hexythiazox as well as the NOAEL and the lowest-observed-adverse-effect-level (LOAEL) from the toxicity studies can be found at http://www.regulations.gov in document “Hexythiazox. Human Health Risk Assessment to Support Amended Use on Grapes Reducing the Preharvest Interval from 28-Days to 7-Days and to Add Uses on Turf, Gardens and Ornamentals,” page 27 in docket ID number EPA-HQ-OPP-2009-0325.
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 NOAEL and the LOAEL of concern are identified. Uncertainty/safety factors are used in conjunction with the POD to calculate a safe exposure level generally referred to as a PAD or a 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 hexythiazox used for human risk assessment can be found at http://www.regulations.gov in document “Hexythiazox.” “Human Health Risk Assessment to Support Amended Use on Grapes Reducing the Preharvest Interval from 28-Days to 7-Days and to Add Uses on Turf, Gardens and Ornamentals,” page 12 in docket ID number EPA-HQ-OPP-2009-0325
ii. Chronic exposure. In conducting the chronic dietary exposure assessment EPA used the food consumption data from the U.S. Department of Agriculture (USDA) 1994-1996 and 1998 Continuing Surveys of Food Intakes by Individuals (CSFII). As to residue levels in food, EPA used tolerance level residues, assumed 100 percent crop treated (PCT), and incorporated default processing factors.
iii. Cancer. As discussed in this unit, EPA has determined that the chronic RfD is sufficient to evaluate all chronic Start Printed Page 12693risks for this chemical, including carcinogenic potential. Cancer risk was quantified using the same estimates as discussed in Unit III.C.1.ii., chronic exposure.
Based on the Pesticide Root Zone Model/Exposure Analysis Modeling System (PRZM/EXAMS) the estimated drinking water concentration (EDWC) of hexythiazox for chronic exposures for non-cancer and cancer assessments is estimated to be 4.1 parts per billion (ppb) for surface water. Since surface water residue values greatly exceed groundwater EDWCs, surface water residues were used in the dietary risk assessment.
The modeled EDWC was directly entered into the dietary exposure model.
Hexythiazox is not currently registered for any specific use patterns that would result in residential exposure. However, the following uses that could result in residential exposures are pending registration in the near future and are included in this risk assessment: Turf, gardens, ornamental landscape plantings, ornamental plants, trees and vines in nurseries, residential fruit trees, nut trees and caneberries, and orchids. Residential handler exposures are expected to be short-term (1 to 30 days) via either the dermal or inhalation routes of exposures. Since a quantitative dermal risk assessment is not required for hexythiazox; MOEs were calculated for the inhalation route of exposure only. Both adults and children may be exposed to hexythiazox residues from contact with treated lawns or treated residential plants. Adult postapplication exposures were not assessed since no quantitative dermal risk assessment is required for hexythiazox and inhalation exposures are typically negligible in outdoor settings. The exposure assessment for children included incidental oral exposure resulting from transfer of residues from the hands or objects to the mouth, and from incidental ingestion of soil. No quantitative dermal risk assessment is required.
Residential handler risks are not of concern as short-term inhalation MOEs range from 40,000,000 to 820,000,000. Postapplication risks for children are not of concern as incidental oral short-term MOEs range from 2,600 to 3,200,000 and intermediate-term MOEs range from 5,600 to 3,200,000 ( MOEs which exceed 100 are not of concern). None of the subject uses are expected to result in long-term residential exposures.
iii. There is no evidence that hexythiazox results in increased susceptibility in in utero rats or rabbits in the prenatal developmental studies or in young rats in the two-generation reproduction study
iv. There are no residual uncertainties identified in the exposure databases. The dietary food exposure assessments were performed based on 100 PCT and tolerance-level residues. The dietary risk assessment is highly conservative and not expected to underestimate risk. EPA made conservative (protective) assumptions in the ground and surface water modeling used to assess exposure to hexythiazox in drinking water. EPA Start Printed Page 12694used similarly conservative assumptions to assess postapplication exposure of children as well as incidental oral exposure of toddlers. These assessments will not underestimate the exposure and risks posed by hexythiazox.
EPA determines whether acute and chronic dietary pesticide exposures are safe by comparing aggregate exposure estimates to the acute population adjusted-dose (aPAD) and chronic population adjusted-dose (cPAD). For linear cancer risks, EPA calculates the lifetime probability of acquiring cancer given the estimated aggregate exposure. Short-term, intermediate-term, 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.
1. Acute risk An acute aggregate risk assessment takes into account acute exposure estimates from dietary consumption of food and drinking water. No adverse effect resulting from a single oral exposure was identified and no acute dietary endpoint was selected. Therefore, hexythiazox is not expected to pose an acute risk.
2. Chronic risk. Using the exposure assumptions described in this unit for chronic exposure, EPA has concluded that chronic exposure to hexythiazox from food and water will utilize 49% 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 hexythiazox is not expected.
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 aggregate MOEs of 16,000 for adults and 1,300 for children. Because EPA's level of concern for hexythiazox is a MOE of 100 or below, these MOEs are not of concern.
Using the exposure assumptions described in this unit for intermediate-term exposures, EPA has concluded that the combined intermediate-term food, water, and residential exposures result in aggregate MOEs of 16,000 for adults and 1,700 for children. Because EPA's level of concern for hexythiazox is a MOE of 100 or below, these MOEs are not of concern.
5. Aggregate cancer risk for U.S. population. EPA has classified hexythiazox as “Likely to be Carcinogenic to Humans,” but has determined that there is insufficient evidence to quantify risk using a cancer slope factor. As discussed in Unit III.A EPA concluded that regulation based on the chronic RfD will be protective for both chronic and carcinogenic risks. As noted in this unit there are no chronic risks of concern.
Adequate enforcement methodology (high performance liquid chromatography with UV detection (HPLC/UV)) is available to enforce the tolerance expression. The method may be requested from: Chief, Analytical Chemistry Branch, Environmental Science Center, 701 Mapes Rd., Ft. Meade, MD 20755-5350; telephone number: (410) 305-2905; e-mail address: residuemethods@epa.gov.
A Codex MRL is established at 1.0 ppm for grape. The Agency has harmonized the residue level, but notes that it is not possible to harmonize the tolerance expression at this time as the Codex maxium residue limit (MRL) includes parent only. There are no currently established Canadian or Mexican MRLs for residues of hexythiazox in/on grape.
The Agency has revised the tolerance expression to clarify 1. that, as provided in FFDCA section 408(a)(3), the tolerance covers metabolites and degradates of hexythiazox not specifically mentioned; and 2. that compliance with the specified tolerance levels is to be determined by measuring only the specific compounds mentioned in the tolerance expression. The Agency determined that there is insufficient residue chemistry data to support the proposed tolerances for the stone fruit use; therefore, this action only addresses the tolerance for grape.
Therefore, the tolerance for residues of hexythiazox, in or on grape is revised from 0.75 ppm to 1.0 ppm.
This final rule directly regulates growers, food processors, food handlers, and food retailers, not States or tribes, nor does this action alter the relationships or distribution of power Start Printed Page 12695and responsibilities established by Congress in the preemption provisions of section 408(n)(4) of FFDCA. As such, the Agency has determined that this action will not have a substantial direct effect on States or tribal governments, on the relationship between the national government and the States or tribal governments, or on the distribution of power and responsibilities among the various levels of government or between the Federal Government and Indian tribes. Thus, the Agency has determined that Executive Order 13132, entitled Federalism (64 FR 43255, August 10, 1999) and Executive Order 13175, entitled Consultation and Coordination with Indian Tribal Governments (65 FR 67249, November 9, 2000) do not apply to this final rule. In addition, this final rule does not impose any enforceable duty or contain any unfunded mandate as described under Title II of the Unfunded Mandates Reform Act of 1995 (UMRA) (Public Law 104-4).
2. § 180.448 revise the introductory text in paragraph (a), and revise the entry “Grape“ in the table in paragraph (a), and revise introductory text in paragraphs (b), and (c) to read as follows:
(a) General. Tolerances are established for residues of hexythiazox, including its metabolites and degradates, in or on the commodities in the table below. Compliance with the tolerance levels specified below is to be determined by measuring only hexythiazox and its metabolites containing the (4-chlorophenyl)-4-methyl-2-oxo-3-thiazolidine moiety, calculated as the stoichiometric equivalent of hexythiazox.
(b) Section 18 emergency exemptions. Time-limited tolerances are established for residues of hexythiazox, including its metabolites and degradates, in connection with use of the pesticide under section 18 emergency exemptions granted by EPA. Compliance with the tolerance levels specified below is to be determined by measuring only hexythiazox and its metabolites containing the (4-chlorophenyl)-4-methyl-2-oxo-3-thiazolidine moiety, calculated as the stoichiometric equivalent of hexythiazox. These tolerances will expire and are revoked on the dates specified in the following table:
(c) Tolerances with regional registrations. Tolerances with regional registrations as defined by 40CFR 180.1(n), are established for residues of hexythiazox, including its metabolites and degradates, in or on the commodities in the table below. Compliance with the tolerance levels specified below is to be determined by measuring only hexythiazox and its metabolites containing the (4-chlorophenyl)-4-methyl-2-oxo-3-thiazolidine moiety, calculated as the stoichiometric equivalent of hexythiazox.
[FR Doc. 2010-5692 Filed 3-16-10; 8:45 am]