Pesticides; tolerances in food, animal feeds, and raw agricultural commodities: Terbacil,

[Federal Register: May 31, 2006 (Volume 71, Number 104)]

[Rules and Regulations]

[Page 30811-30818]

From the Federal Register Online via GPO Access [wais.access.gpo.gov]

[DOCID:fr31my06-10]

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[EPA-HQ-OPP-2005-0215; FRL-8057-9]

Terbacil; Pesticide Tolerance

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

SUMMARY: This regulation establishes a tolerance for combined residues of terbacil in or on watermelon. The Interregional Research Project Number 4 (IR-4), on behalf of the registrant, DuPont Crop Protection, requested this tolerance under the Federal Food, Drug, and Cosmetic Act (FFDCA), as amended by the Food Quality Protection Act of 1996 (FQPA). EPA is also deleting an existing time-limited terbacil tolerance that is no longer needed as a result of this action.

DATES: This regulation is effective May 31, 2006. Objections and requests for hearings must be received on or before July 31, 2006, 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: EPA has established a docket for this action under docket identification (ID) number EPA-HQ-OPP-2005-0215. All documents in the docket are listed in the index for the docket. Although listed in the index, some information is not publicly available, e.g., Confidential Business Information (CBI) or other information

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whose disclosure is restricted by statute. Certain other material, such as copyrighted material, is not placed on the Internet and will be publicly available only in hard copy form. Publicly available docket materials are available in the electronic docket at http://www.regulations.gov , or, if only available in hard copy, at the OPP

Regulatory Public Docket in Rm. S-4400, One Potomac Yard (South Building), 2777 S. Crystal Drive, Arlington, VA. The Docket Facility is open from 8:30 a.m. to 4 p.m., Monday through Friday, excluding legal holidays. The telephone number for the Docket Facility is (703) 305- 5805.

FOR FURTHER INFORMATION CONTACT: Sidney Jackson, Registration Division (7505P), Office of Pesticide Programs, Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone number: (703) 305-7610; e-mail address: jackson.sidney@epa.gov.

SUPPLEMENTARY INFORMATION:

1. General Information

   1. 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:

      Crop production (NAICS 111), e.g., agricultural workers; greenhouse, nursery, and floriculture workers; farmers.

      Animal production (NAICS 112), e.g., cattle ranchers and farmers, dairy cattle farmers, livestock farmers.

      Food manufacturing (NAICS 311), e.g., agricultural workers; farmers; greenhouse, nursery, and floriculture workers; ranchers; pesticide applicators.

      Pesticide manufacturing (NAICS 32532), e.g., agricultural workers; commercial applicators; farmers; greenhouse, nursery, and floriculture workers; residential users.

      This listing is not intended to be exhaustive, but rather provides 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.

   2. How Can I Access Electronic Copies of this Document?

      In addition to accessing an electronic copy of this Federal Register document through the electronic docket at http://www.regulations.gov , you may access this Federal Register document

      electronically through the EPA Internet under the ``Federal Register'' listings at http://www.epa.gov/fedrgstr. You may also access a

      frequently updated electronic version of 40 CFR part 180 through the Government Printing Office's pilot e-CFR site at http://www.gpoaccess.gov/ecfr. To access the OPPTS Harmonized Guidelines

      referenced in this document, go directly to the guidelines at http://www.epa.gov/opptsfrs/home/guidelin.htm .

   3. Can I File an Objection or Hearing Request?

      Under section 408(g) of the FFDCA, as amended by the FQPA, any person may file an objection to any aspect of this regulation and may also request a hearing on those objections. The EPA procedural regulations which govern the submission of objections and requests for hearings appear in 40 CFR part 178. 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-2005-0215 in the subject line on the first page of your submission. All requests must be in writing, and must be mailed or delivered to the Hearing Clerk on or before July 31, 2006.

      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 your copies, identified by docket ID number EPA-HQ-OPP-2005-0215, by one of the following methods:

      Federal eRulemaking Portal: http://www.regulations.gov.

      Follow the on-line instructions for submitting comments.

      Mail: Office of Pesticide Programs (OPP) Regulatory Public Docket (7502P), Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460-0001.

      Delivery: OPP Regulatory Public Docket (7502P), Environmental Protection Agency, Rm. S-4400, One Potomac Yard (South Building), 2777 S. Crystal Drive, Arlington, VA. Deliveries are only accepted during the Docket's normal hours of operation (8:30 a.m. to 4 p.m., Monday through Friday, excluding legal holidays). Special arrangements should be made for deliveries of boxed information. The telephone number for the Docket Facility is (703) 305-5805.

2. Background and Statutory Findings

   In the Federal Register of September 7, 2005 (70 FR 53180) (FRL- 7731-1), 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 3E6640) by IR-4, on behalf of DuPont Crop Protection, P.O. Box 30, Newark, Delaware 19714-0030. The petition requested that 40 CFR 180.209 be amended by establishing a tolerance for combined residues of the herbicide terbacil, (3-tert-butyl-5-chloro-6-methyluracil) and its metabolites [3-tert-butyl-5-chloro-6-hydroxymethyluracil], [6-chloro- 2,3-dihydro-7-hydroxymethyl 3,3-dimethyl-5H-oxazolo(3,2-a) pyrimidin-5- one], and [6-chloro-2,3-dihydro-3,3,7-trimethyl-5H-oxazolo(3,2-a) pyrimidin-5-one], in or on watermelon at 1.0 parts per million (ppm). That notice included a summary of the petition prepared by DuPont Crop Protection, the registrant. There were no comments received in response to the notice of filing.

   EPA is also deleting an established tolerance in section 40 CFR 180.209(b) that is no longer needed, as a result of this action. The tolerance deletion under section 40 CFR 180.209(b) is a time-limited tolerance established under section 18 emergency exemptions that is superceded by the establishment of a general tolerance for terbacil section 40 CFR 180.209(a). The revision to 40 CFR 180.209 is as follow:

   Delete the time-limiting tolerance for watermelon at 0.4 ppm under 40 CFR 180.209(b). Tolerance for watermelon at 1.0 ppm is established by this action under 40 CFR 180.209(a).

   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

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   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 of the FFDCA and a complete description of the risk assessment process, see http://www.epa.gov/fedrgstr/EPA-PEST/ 1997/November/Day-26/p30948.htm.

3. Aggregate Risk Assessment and Determination of Safety

   Consistent with section 408(b)(2)(D) of FFDCA, 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, consistent with section 408(b)(2) of FFDCA, for a tolerance for combined residues of terbacil on watermelon at 1.0 ppm. EPA's assessment of exposures and risks associated with establishing the tolerance follows.

   1. Toxicological Profile

      EPA has evaluated the available toxicity data and considered their 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. Specific information on the studies received and the nature of the toxic effects caused by terbacil as well as the no observed adverse effect level (NOAEL) and the lowest observed adverse effect level (LOAEL) from available toxicity studies as summarized in Table 1 below:

      Table 1: Toxicity Profile for Terbacil -- Subchronic, Chronic and Other Toxicity

      Guideline No.

      Study Type Assessment Results

      870.3100

      90-Day oral

      NOAEL = 500 ppm toxicity rat

      (20 mg/kg/day) Dosage at 0, 8, LOAEL = 5,000 ppm 20, and 200

      (200 mg/kg/day), milligrams/

      based on focal kilogram/day (mg/ necrosis and kg/day).

      triaditis in females (F), vacuolization in males (M) and increased relative liver weight and hypertrophy of hepatocytes in both sexes.

      870.3200

      21-Day dermal NOAEL = 5,000 mg/ rabbit

      kg/day Dosage at 0 and LOAEL was not 5,000 mg/kg/day. established. There were no clinical signs of toxicity, gross or histopathologic changes.

      870.4100

      Chronic oral 2- NOAEL = 250 ppm year dog

      (equivalent to Dosage at 0, 1.0, 5.0 mg/kg/day) 5.0, 50, and 200 LOAEL = 2500 ppm mg/kg/day.

      (equivalent to 50 mg/kg/day), based on increased relative thyroid weights and thymic involution in both sexes.

      870.4200

      Carcinogenicity NOAEL = 162 mg/kg/ mouse

      day Dosage for M/F: 0/ LOAEL = 746 mg/kg/ 0, 6.5/8.0, 162/ day, based on 199, and 746/895 increased liver mg/kg/day.

      weights, hyperplastic nodules, necrosis, and vacuolation in the liver in males. There was no oncogenic potential at the doses tested.

      870.3700

      Developmental Maternal NOAEL was toxicity rat

      not established Dosage at 0, 24, Maternal LOAEL = 104 and 392 mg/kg/ 24 mg/kg/day day.

      based on decreased body weight gain. Developmental NOAEL = 24 mg/kg/ day Developmental LOAEL = 104 mg/kg/ day, based on decreased number of live fetuses/ litter.

      870.3700

      Developmental Maternal NOAEL = Toxicity rabbit 200 mg/kg/day Dosage at 0, 30, Maternal LOAEL = 200, and 600 mg/ 600 mg/kg/day, kg/day.

      based on mortality, clinical findings (anorexia, discharge), decreased body weight and body weight gain. Developmental NOAEL = 200 mg/kg/ day Developmental LOAEL = 600 mg/kg/ day, based on decreased body weight, increased incidence of skeletal malformations (fused ribs) and increase frequency of skeletal variations.

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      870.3800

      3-generation

      Parental NOAEL = reproduction - 50 ppm rat

      (equivalent to2.0 Dosage at 0, 2.0, mg/kg/day) and 10 mg/kg/day. Parental LOAEL = 250 ppm (equivalent to 10 mg/kg/day) based on decreased body weight, Reproductive NOAEL = 250 ppm (equivalent to 10 mg/kg/day) Reproductive LOAEL was not established Offspring NOAEL = 250 ppm (equivalent to 10 mg/kg/day) Offspring LOAEL was not established

      870.4300

      Combined Chronic NOAEL (M/F)= 58/ Toxicity/

      1.4 mg/kg/day Carcinogenicity LOAEL (M/F)= 308/ rat

      83 mg/kg/day, Dosage M/F: 0/0, based on 0.9/1.4, 58/83, decreased body 308/484 mg/kg/day. weight and body weight gain and increased absolute and relative liver weights in males and females. There was no oncogenic potential at the doses tested.

      870.4300

      Combined Chronic Systemic NOAEL = Toxicity/

      250 ppm Carcinogenicity (equivalent to 10 rat

      mg/kg/day) Dosage at 0, 2.0, Systemic LOAEL = 10 and 100/400 mg/ 2,500/10,000 ppm kg/day).

      (equivalent to 100/400 mg/kg/ day) based on increased mean relative liver weights, hepatocyte centrilobular hypertrophy in males and females and vacuolation in females. There was no oncogenic potential at the doses tested.

      870.5300

      Mutagenic- (HGPRT) Did not induce Dosage at 0, 2, 3, mutation in 5 and 6 mM (-S9); chinese hamster 0, 1, 2, 2.5, ovary cells with 2.75, 3.25 and or without 3.50 mM (+S9). metabolic activation.

      870.5375

      In vitro

      Negative for chromosome

      clastogenic aberration assay activity in the CHO cells

      rat bone marrow Dosage at 0, 20, cytogenetic 100 and 500 mg/kg. assay.

      870.5500

      Unscheduled DNA Did not induce synthesis assay unscheduled DNA rat primary

      synthesis in hepatocyte

      primary rat Dosage at 0,

      hepatocytes. 0.010, 0.033, 0.10, 0.33, 1.0, 2.5, 5.0, 7.5, and 10 mM.

      870.5100

      Mutagenicity Did not show the study

      suspected (5- (bacteriophage bromo-uracil assay)

      metabolite) mutagenic action.

      870.7485

      Metabolism study Approximately 57- rat

      82% of the Doseage at single administered dose doses of 6.5 or was absorbed in 500 mg/kg.

      24 hours. Ninety one to 103% of radioactivity was recovered within 5 days; with 70 to 86% in urine and 14-28% in feces. The major metabolites were glucuronide, sulfate and sulfate/N- acetylcysteine conjugates. The primary metabolic pathway is hydroxylation of the 6-methyl group to form the alcohol which is conjugated to form the glucuronide (35% of the dose) and the sulfate derivatives (11%). Terbacil is also metabolized to the 5-hydroxy intermediate, which is further conjugated to form a sulfate derivative (17%). There was no evidence suggestive of bioaccumulation.

   2. Toxicological Endpoints

      For hazards that have a threshold below which there is no appreciable risk, the dose at which the NOAEL from the toxicology study identified as appropriate for use in risk assessment is used to estimate the toxicological level of concern (LOC). However, the LOAEL is sometimes used for risk assessment if no NOAEL was achieved in the toxicology study selected. An uncertainty factor (UF) is applied to reflect uncertainties inherent in the extrapolation from laboratory animal data to humans and in the variations in sensitivity among members of the human population as well as other unknowns.

      The linear default risk methodology (Q*) is the primary method currently used by the Agency to quantify non-threshold hazards such as cancer. The Q* approach assumes that any amount of exposure will lead to some degree of cancer risk, estimates risk in terms of the probability of occurrence of additional cancer cases. More information can be found on the general principles EPA uses in risk

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      characterization at http://www.epa.gov/pesticide/health/human.htm.

      A summary of the toxicological endpoints for terbacil used for human risk assessment is presented in the following Table 2:

      Table 2.--Summary of Toxicological Dose and Endpoints for terbacil for Use in Human Risk Assessment

      Dose Used in Risk Assessment,

      Special FQPA SF and Exposure/Scenario

      Interspecies and Level of Concern for Study and Toxicological Intraspecies and any Risk Assessment

      Effects Traditional UF

      Acute Dietary

      NA

      NA

      An endpoint of concern (General Population and Females 13-50

      attributable to a years of age).

      single dose for the general population or female 13+ was not identified

      Chronic dietary (All populations) NOAEL= 1.4 mg/kg/day Special FQPA SF = 1X Combined Chronic UF = 100X.............. cPAD = cRfD divided by. Toxicity/ Chronic RfD = cRfD= Special FQPA SF........ carcinogenicity - rat 0.014 mg/kg/day.

      = 0.014 mg/kg/day..... LOAEL = 83 mg/kg/day based on decreased body weight and body weight gain in females

      Short (1-30 days) and Intermediate (1- Oral NOAEL = 2.0 mg/kg/ LOC for margin of

      3-Generation 6 months) Term Incidental oral

      day (inhalation

      exposure (MOEs) 6 months) Oral NOAEL= 1.4 mg/kg/ LOC for MOE