Pesticide Tolerances:

Federal Register: April 22, 2011 (Volume 76, Number 78)

Rules and Regulations

Page 22620-22625

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

DOCID:fr22ap11-12

ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 180

EPA-HQ-OPP-2010-0102; FRL-8871-4

Triflusulfuron-Methyl; Pesticide Tolerances

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

SUMMARY: This regulation establishes tolerances for residues of triflusulfuron-methyl in or on beet, garden, roots and beet, garden, tops. Interregional Research Project Number 4 (IR-4) requested these tolerances under the Federal Food, Drug, and Cosmetic Act (FFDCA).

DATES: This regulation is effective April 22, 2011. Objections and requests for hearings must be received on or before June 21, 2011, 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-2010-0102. All documents in the docket are listed in the docket index available at http:// www.regulations.gov. Although listed in the index, some information is not publicly available, e.g., Confidential Business Information (CBI) or other information 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 Bldg.), 2777 S. Crystal Dr., Arlington, VA. The Docket

Facility is open from 8:30 a.m. to 4 p.m., Monday through Friday, excluding legal holidays. The Docket Facility telephone number is (703) 305-5805.

FOR FURTHER INFORMATION CONTACT: Laura Nollen, Registration Division

(7505P), Office of Pesticide Programs, Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone number: (703) 305-7390; e-mail address: nollen.laura@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 those engaged in the following activities:

      Crop production (NAICS code 111).

      Animal production (NAICS code 112).

      Food manufacturing (NAICS code 311).

      Pesticide manufacturing (NAICS code 32532).

      This listing is not intended to be exhaustive, but rather to provide a guide for readers regarding entities likely to be affected by this action. Other types of entities not listed in this unit could also be affected. The North American Industrial Classification System

      (NAICS) codes have been provided to assist you and others in determining whether this action might apply to certain entities. If you have any questions regarding the applicability of this action to a particular entity, consult the person listed under FOR FURTHER

      INFORMATION CONTACT.

   2. How can I get electronic access to other related information?

      You may access a frequently updated electronic version of EPA's tolerance regulations at 40 CFR part 180 through the Government

      Printing Office's e-CFR site at http://www.gpoaccess.gov/ecfr.

   3. How can I file an objection or hearing request?

      Under FFDCA section 408(g), 21 U.S.C. 346a, any person may file an objection to any aspect of this regulation and may also request a hearing on those objections. You must file your objection or request a hearing on this regulation in accordance with the instructions provided in 40 CFR part 178. To ensure proper receipt by EPA, you must identify docket ID number EPA-HQ-OPP-2010-0102 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

      June 21, 2011. Addresses for mail and hand delivery of objections and hearing requests are provided in 40 CFR 178.25(b).

      In addition to filing an objection or hearing request with the

      Hearing Clerk as described in 40 CFR part 178, please submit a copy of the filing that does not contain any CBI for inclusion in the public docket. Information not marked confidential pursuant to 40 CFR part 2 may be disclosed publicly by EPA without prior notice. Submit a copy of your non-CBI objection or hearing request, identified by docket ID number EPA-HQ-OPP-2010-0102, 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

      Bldg.), 2777 S. Crystal Dr., Arlington, VA. Deliveries are only accepted during the Docket Facility'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

      Page 22621

      Docket Facility telephone number is (703) 305-5805.

2. Summary of Petitioned-For Tolerances

   In the Federal Register of March 19, 2010 (75 FR 13277) (FRL-8813- 2), 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 9E7669) by IR-4, 500 College Road East, Suite 201 W., Princeton, NJ 08540. The petition requested that 40 CFR 180.492 be amended by establishing tolerances for residues of the herbicide triflusulfuron- methyl, 2-[4-(dimethylamino)-6-(2,2,2-trifluoroethoxy)-1,3,5- triazin-2-yl]amino]carbonyl]amino]sulfonyl]-3-methylbenzoate, in or on beet, garden, roots at 0.01 parts per million (ppm); and beet, garden, tops at 0.02 ppm. That notice referenced a summary of the petition prepared on behalf of IR-4 by DuPont Crop Protection, the registrant, which is available in the docket, http://www.regulations.gov. Comments were received on the notice of filing. EPA's response to these comments is discussed in Unit IV.C.

   EPA has revised the tolerance expression for all established commodities to be consistent with current Agency policy and has made a technical correction to the chemical name. The reasons for these changes are explained in Unit IV.D.

3. Aggregate Risk Assessment and Determination of Safety

   Section 408(b)(2)(A)(i) of FFDCA allows EPA to establish a tolerance (the legal limit for a pesticide chemical residue in or on a food) only if EPA determines that the tolerance is ``safe.'' Section 408(b)(2)(A)(ii) of FFDCA defines ``safe'' to mean that ``there is a reasonable certainty that no harm will result from aggregate exposure to the pesticide chemical residue, including all anticipated dietary exposures and all other exposures for which there is reliable information.'' This includes exposure through drinking water and in residential settings, but does not include occupational exposure.

   Section 408(b)(2)(C) of FFDCA requires EPA to give special consideration to exposure of infants and children to the pesticide chemical residue in establishing a tolerance and to ``ensure that there is a reasonable certainty that no harm will result to infants and children from aggregate exposure to the pesticide chemical residue. * *

   *''

   Consistent with section 408(b)(2)(D) of FFDCA, and the factors specified in 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 for triflusulfuron-methyl, including exposure resulting from the tolerances established by this action. EPA's assessment of exposures and risks associated with triflusulfuron-methyl follows.

   1. 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.

      Triflusulfuron-methyl is of low acute toxicity when administered orally, dermally, or via inhalation. It is not a dermal sensitizer or irritant, and causes only minor transient irritation to the eye. The primary target organs identified for triflusulfuron-methyl are the liver, testes, and red blood cells. Hematological and histopathological changes consistent with mild hemolytic anemia were observed in the rat and the dog. Following subchronic and/or chronic dietary exposure, increased incidence of testicular interstitial hyperplasia was observed in the rat, and testicular atrophy and reduced size were observed in the dog. Liver effects including histopathology and increased weight were observed in the dog and mouse, but not in the rat.

      No evidence of neurotoxicity was observed except for a statistically significant increase in sciatic nerve myelin/axon degeneration in female rats at the highest dose tested in the rat combined chronic toxicity/carcinogenicity study. However, the incidence was high in all dose groups, no increases were seen in the interim sacrifice groups or in shorter-term studies, and it is commonly observed in older rats.

      In the rat developmental toxicity study, no developmental effects were noted, whereas maternal toxicity was observed (decreased body weight gain, food consumption and feed efficiency). Abortions occurred in the rabbit developmental toxicity study at a dose that also caused significant maternal toxicity, including mortality, clinical signs, sharply reduced food consumption and decreased weight gain. In the rat reproductive toxicity study, decreased parental body weight/weight gain and offspring weight during lactation were observed at the mid and high doses. No reproductive effects were observed.

      Triflusulfuron-methyl is classified as a possible human carcinogen

      (Group C) under the 1986 Cancer Guidelines, based on an increased incidence of benign testicular interstitial cell adenomas in male rats in the combined chronic/carcinogenicity toxicity study and evidence of clastogenicity in some in vitro genotoxicity studies. A special mechanistic study that evaluated hormonal changes in male rats provided insufficient information to establish a nonlinear mode of action for the formation of these tumors. Additionally, although a statistically significant incidence of hepatocellular adenomas was noted in a carcinogenicity study in mice, it was within the historical control range and not considered as part of the weight-of-evidence for determination of cancer classification. Because the observed tumors were benign and found in only one species, and only at significantly higher dose levels than the dose selected for the point of departure, the chronic reference dose (RfD) is considered protective of potential carcinogenicity for risk assessment purposes.

      Specific information on the studies received and the nature of the adverse effects caused by triflusulfuron-methyl as well as the no- observed-adverse-effect-level (NOAEL) and the lowest-observed-adverse- effect-level (LOAEL) from the toxicity studies can be found at http:// www.regulations.gov in document ``Triflusulfuron-methyl: Revised Human

      Health Risk Assessment for Use in Garden Beet.'' at pages 34-38 in docket ID number EPA-HQ-OPP-2010-0102.

   2. Toxicological Points of Departure/Levels of Concern

      Once a pesticide's toxicological profile is determined, EPA identifies toxicological points of departure (POD) and levels of concern to use in evaluating the risk posed by human exposure to the pesticide. For hazards that have a threshold below which there is no appreciable risk, the toxicological POD is used as the basis for derivation of reference values for risk assessment. PODs are developed based on a careful analysis of the doses in each toxicological study to determine the dose at which no adverse effects are observed (the NOAEL) and the lowest dose at which adverse effects of concern are identified

      (the LOAEL). Uncertainty/safety factors are used in conjunction with the POD to calculate a safe exposure level--generally referred to as a population-adjusted dose (PAD) or a RfD--and a safe margin of exposure

      Page 22622

      (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 triflusulfuron-methyl used for human risk assessment is shown in Table 1 of this unit.

      Table 1--Summary of Toxicological Doses and Endpoints for Triflusulfuron-Methyl for Use in Human Health Risk

      Assessment

      Point of departure and

      Exposure/scenario

      uncertainty/safety

      RfD, PAD, LOC for risk

      Study and toxicological factors

      assessment

      effects

      Acute dietary (Females 13-49 years

      Not required. An appropriate endpoint for this risk assessment was not of age and General population,

      identified. including infants and children).

      Chronic dietary (All populations).. NOAEL= 2.44 mg/kg/day. Chronic RfD = 0.0244

      Chronic oral toxicity/

      UFA = 10x

      mg/kg/day.

      carcinogenicity in the

      UFH = 10x

      cPAD = 0.0244 mg/kg/

      rat LOAEL = 30.6 mg/kg/

      FQPA SF = 1x

      day.

      day based on decreased body weight/weight gain, hematological changes

      (primarily males) and increased interstitial cell hyperplasia (males).

      Cancer (Oral, dermal, inhalation)..

      Classification: Possible Human Carcinogen (Group C, 1986 Cancer

      Guidelines), based on increased incidence of testicular interstitial cell adenomas in rats. The RfD is considered adequately protective of these effects.

      FQPA SF = Food Quality Protection Act Safety Factor.

      PAD = population adjusted dose (a = acute, c = chronic).

      UFA = extrapolation from animal to human (interspecies).

      UFH = potential variation in sensitivity among members of the human population (intraspecies).

   3. Exposure Assessment 1. Dietary exposure from food and feed uses. In evaluating dietary exposure to triflusulfuron-methyl, EPA considered exposure under the petitioned-for tolerances as well as all existing triflusulfuron-methyl tolerances in 40 CFR 180.492. EPA assessed dietary exposures from triflusulfuron-methyl in food as follows: i. Acute exposure. Quantitative acute dietary exposure and risk assessments are performed for a food-use pesticide, if a toxicological study has indicated the possibility of an effect of concern occurring as a result of a 1-day or single exposure. No such effects were identified in the toxicological studies for triflusulfuron-methyl; therefore, a quantitative acute dietary exposure assessment is unnecessary. ii. Chronic exposure. In conducting the chronic dietary exposure assessment, EPA used the food consumption data from the USDA 1994-1996 and 1998 Continuing Surveys of Food Intakes by Individuals (CSFII). As to residue levels in food, EPA utilized tolerance-level residues and 100 percent crop treated (PCT) for all commodities. iii. Cancer. EPA determines whether quantitative cancer exposure and risk assessments are appropriate for a food-use pesticide based on the weight of the evidence from cancer studies and other relevant data.

      Cancer risk is quantified using a linear or nonlinear approach. If sufficient information on the carcinogenic mode of action is available, a threshold or non-linear approach is used and a cancer RfD is calculated based on an earlier noncancer key event. If carcinogenic mode of action data are not available, or if the mode of action data determines a mutagenic mode of action, a default linear cancer slope factor approach is utilized. Based on the data summarized in Unit

      III.A., EPA has concluded that the use of the chronic RfD is considered protective of potential carcinogenicity for risk assessment purposes. iv. Anticipated residue and PCT information. EPA did not use anticipated residue and/or PCT information in the dietary assessment for triflusulfuron-methyl. Tolerance level residues and/or 100 PCT were assumed for all food commodities. 2. Dietary exposure from drinking water. The Agency used screening level water exposure models in the dietary exposure analysis and risk assessment for triflusulfuron-methyl in drinking water. These simulation models take into account data on the physical, chemical, and fate/transport characteristics of triflusulfuron-methyl. Further information regarding EPA drinking water models used in pesticide exposure assessment can be found at http://www.epa.gov/oppefed1/models/ water/index.htm.

      Based on the Pesticide Root Zone Model/Exposure Analysis Modeling

      System (PRZM/EXAMS) and Screening Concentration in Ground Water (SCI-

      GROW) models, the estimated drinking water concentrations (EDWCs) of triflusulfuron-methyl for chronic exposures for non-cancer assessments are estimated to be 0.005 parts per billion (ppb) for surface water and 0.50 ppb for ground water.

      Modeled estimates of drinking water concentrations were directly entered into the dietary exposure model. For chronic dietary risk assessment, the water concentration of value 0.50 ppb was used to assess the contribution to drinking water. 3. From non-dietary exposure. The term ``residential exposure'' is used in this document to refer to non-occupational, non-dietary exposure (e.g., for lawn and garden pest control, indoor pest control, termiticides, and flea and tick control on pets). Triflusulfuron-methyl is not registered for any specific use patterns that would result in residential exposure. 4. Cumulative effects from substances with a common mechanism of toxicity. Section 408(b)(2)(D)(v) of FFDCA requires that, when considering whether to establish, modify, or revoke a tolerance, the

      Agency consider ``available information'' concerning the cumulative effects of a particular pesticide's residues and ``other

      Page 22623

      substances that have a common mechanism of toxicity.'' EPA has not found triflusulfuron-methyl to share a common mechanism of toxicity with any other substances, and triflusulfuron-methyl does not appear to produce a toxic metabolite produced by other substances. For the purposes of this tolerance action, therefore, EPA has assumed that triflusulfuron-methyl does not have a common mechanism of toxicity with other substances. For information regarding EPA's efforts to determine which chemicals have a common mechanism of toxicity and to evaluate the cumulative effects of such chemicals, see EPA's Web site at http:// www.epa.gov/pesticides/cumulative.

   4. Safety Factor for Infants and Children 1. In general. Section 408(b)(2)(C) of FFDCA provides that EPA shall apply an additional tenfold (10X) margin of safety for infants and children in the case of threshold effects to account for prenatal and postnatal toxicity and the completeness of the database on toxicity and exposure unless EPA determines based on reliable data that a different margin of safety will be safe for infants and children. This additional margin of safety is commonly referred to as the FQPA Safety

      Factor (SF). In applying this provision, EPA either retains the default value of 10X, or uses a different additional safety factor when reliable data available to EPA support the choice of a different factor. 2. Prenatal and postnatal sensitivity. The triflusulfuron-methyl toxicity database is adequate to evaluate potential increased susceptibility of infants and children, and includes developmental toxicity studies in rat and rabbit and a 2-generation toxicity study in rat. No developmental effects were seen in the rat developmental toxicity study. In the rabbit developmental toxicity study, abortions were observed at a dose that also caused significant maternal toxicity, including mortality, clinical signs, sharply reduced food consumption and decreased weight gain. In the rat 2-generation reproductive toxicity study, decreased parental body weight/weight gain and F1 pup weight during lactation were observed at the mid and high doses. No reproductive effects were observed. 3. Conclusion. EPA has determined that reliable data show the safety of infants and children would be adequately protected if the

      FQPA SF were reduced to 1X. That decision is based on the following findings: i. The toxicity database for triflusulfuron-methyl is complete except for immunotoxicity testing. Recent changes to 40 CFR part 158 require immunotoxicity testing (OPPTS Guideline 870.7800) for pesticide registration. However, the existing data are sufficient for endpoint selection for exposure/risk assessment scenarios, and for evaluation of the requirements under the FQPA. There was no evidence of direct immunotoxicity in the available studies. Hemolytic anemia, an effect associated with exposure to some sulfonylurea compounds, was observed for triflusulfuron-methyl. Immune-mediated hemolysis following binding to red blood cells has been reported for sulfonylurea drugs such as chlorpromamide, although it is not clear that the hemolytic anemia observed with triflusulfuron-methyl is related to the immune system.

      However, the hemolytic effects seen in the studies were of low concern because the effects were sporadic and marginal (= 100-fold above the selected PODs. Effects in the dog were seen at doses >= 15- fold higher. The Agency does not believe that an immunotoxicity study will provide a POD lower than that currently used for risk assessment; therefore, an additional UF is not needed to account for the lack of this study. ii. Although a statistically significant increase in sciatic nerve myelin/axon degeneration in high dose female rats was observed in the triflusulfuron-methyl rat combined chronic toxicity/carcinogenicity study, the incidence was high in all dose groups, no increases were seen in the interim sacrifice groups or in shorter-term studies, and the lesion is commonly observed in older rats. Therefore, EPA did not consider this finding to be evidence of frank neurotoxicity, and there is no need for a developmental neurotoxicity study or additional UFs to account for neurotoxicity. iii. There is no evidence that triflusulfuron-methyl results in increased susceptibility in in utero rats or rabbits in the prenatal developmental studies or in young rats in the 2-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. EPA made conservative

      (protective) assumptions in the ground water and surface water modeling used to assess exposure to triflusulfuron-methyl in drinking water.

      These assessments will not underestimate the exposure and risks posed by triflusulfuron-methyl.

   5. Aggregate Risks and Determination of Safety

      EPA determines whether acute and chronic dietary pesticide exposures are safe by comparing aggregate exposure estimates to the acute PAD (aPAD) and chronic PAD (cPAD). For linear cancer risks, EPA calculates the lifetime probability of acquiring cancer given the estimated aggregate exposure. Short-, intermediate-, and chronic-term risks are evaluated by comparing the estimated aggregate food, water, and residential exposure to the appropriate PODs to ensure that an adequate MOE exists. 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, triflusulfuron-methyl 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 triflusulfuron-methyl from food and water will utilize