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

[Federal Register: January 28, 2005 (Volume 70, Number 18)]

[Rules and Regulations]

[Page 4026-4032]

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

[DOCID:fr28ja05-14]

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[OPP-2005-0009; FRL-7695-3]

Quinoxyfen; Pesticide Tolerances for Emergency Exemptions

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

SUMMARY: This regulation establishes time-limited tolerances for residues of quinoxyfen in or on vegetable, cucurbit, subgroup 9A; pumpkin; and squash, winter. This action is in response to EPA's granting of an emergency exemption under section 18 of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) authorizing use of the pesticide on melons, winter squash, and pumpkins. This regulation establishes a maximum permissible level for residues of quinoxyfen in these food commodities. These tolerances will expire and are revoked on December 31, 2007.

DATES: This regulation is effective January 28, 2005. Objections and requests for hearings must be received on or before March 29, 2005.

ADDRESSES: To submit a written objection or hearing request follow the detailed instructions as provided in Unit VII. of the SUPPLEMENTARY INFORMATION. EPA has established a docket for this action under Docket identification (ID) number OPP-2005-0009. All documents in the docket are listed in the EDOCKET index at http://www.epa.gov/edocket. Although

listed in the index, some information is not publicly available, i.e., 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 either electronically in EDOCKET or in hard copy at the Public Information and Records Integrity Branch (PIRIB), Rm. 119, Crystal Mall 2, 1801 S. Bell St., Arlington, VA. This docket facility is open from 8:30 a.m. to 4 p.m., Monday through Friday, excluding legal holidays. The docket telephone number is (703) 305-5805.

FOR FURTHER INFORMATION CONTACT: Barbara Madden, Registration Division (7505C), Office of Pesticide Programs, Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone number: (703) 305-6463; e-mail address: madden.barbara@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)

      Animal production (NAICS 112)

      Food manufacturing (NAICS 311)

      Pesticide manufacturing (NAICS 32532)

      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 and Other Related Information?

      In addition to using EDOCKET (http://www.epa.gov/edocket/), you may

      access this Federal Register document electronically through the EPA Internet under the ``Federal Register'' listings at http://www.epa.gov/fedrgstr/. A frequently updated electronic version of 40 CFR part 180

      is available at E-CFR Beta Site Two at http://www.gpoaccess.gov/ecfr/.

2. Background and Statutory Findings

   EPA, on its own initiative, in accordance with sections 408(e) and 408 (l)(6) of the Federal Food, Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 346a,

   [[Page 4027]]

   is establishing tolerances for residues of the fungicide quinoxyfen, 5,7-dichloro-4-(4-fluorophenoxy)quinoline, in or on vegetable, cucurbit, subgroup 9A; pumpkin; and squash, winter at 0.30 parts per million (ppm). These tolerances will expire and are revoked on December 31, 2007. EPA will publish a document in the Federal Register to remove the revoked tolerance from the Code of Federal Regulations.

   Section 408(l)(6) of the FFDCA requires EPA to establish a time- limited tolerance or exemption from the requirement for a tolerance for pesticide chemical residues in food that will result from the use of a pesticide under an emergency exemption granted by EPA under section 18 of FIFRA. Such tolerances can be established without providing notice or period for public comment. EPA does not intend for its actions on section 18 related tolerances to set binding precedents for the application of section 408 of the FFDCA and the new safety standard to other tolerances and exemptions. Section 408(e) of the FFDCA allows EPA to establish a tolerance or an exemption from the requirement of a tolerance on its own initiative, i.e., without having received any petition from an outside party.

   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) of the 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 the 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. . . .''

   Section 18 of the FIFRA authorizes EPA to exempt any Federal or State agency from any provision of FIFRA, if EPA determines that ``emergency conditions exist which require such exemption.'' This provision was not amended by the Food Quality Protection Act of 1996 (FQPA). EPA has established regulations governing such emergency exemptions in 40 CFR part 166.

3. Emergency Exemption for Quinoxyfen on Melons, Winter Squash, and Pumpkins and FFDCA Tolerances

   There are protectant fungicides registered that are effective in controlling powdery mildew on the upper leaf surfaces of melons, winter squash and pumpkins when the fungicide is in direct contact with the pathogen. However, these fungicides do not provide protection against the pathogen growing on the undersides of the leaves. During the 2003 growing season, resistance of powdery mildew control from the systemic registered alternatives (strobilurins and myclobutanil) was confirmed. The registered strobilurins and myclobutanil proved to be ineffective in controlling powdery mildew in melons, winter squash and pumpkins. The Agency believes that under high disease pressure and disease favorable weather conditions 20-30 percent yield losses are likely without the use of quinoxyfen. EPA has authorized under FIFRA section 18 the use of quinoxyfen on melons, winter squash, and pumpkins for control of powdery mildew in New York. After having reviewed the submission, EPA concurs that emergency conditions exist for this State.

   As part of its assessment of this emergency exemption, EPA assessed the potential risks presented by residues of quinoxyfen in or on cantaloupe, muskmelon, watermelon, watermelon juice, winter squash, pumpkin and pumpkin seed. In doing so, EPA considered the safety standard in section 408(b)(2) of the FFDCA, and EPA decided that the necessary tolerance under section 408(l)(6) of the FFDCA would be consistent with the safety standard and with FIFRA section 18. Consistent with the need to move quickly on the emergency exemption in order to address an urgent non-routine situation and to ensure that the resulting food is safe and lawful, EPA is issuing this tolerance without notice and opportunity for public comment as provided in section 408(l)(6) of the FFDCA. Although this tolerance will expire and is revoked on December 31, 2007, under section 408(l)(5) of the FFDCA, residues of the pesticide not in excess of the amounts specified in the tolerance remaining in or on melon subgroup 9A, pumpkin and winter squash after that date will not be unlawful, provided the pesticide is applied in a manner that was lawful under FIFRA, and the residues do not exceed a level that was authorized by this tolerance at the time of that application. EPA will take action to revoke this tolerance earlier if any experience with, scientific data on, or other relevant information on this pesticide indicate that the residues are not safe.

   Because this tolerance is being approved under emergency conditions, EPA has not made any decisions about whether quinoxyfen meets EPA's registration requirements for use on melons, winter squash, and pumpkins or whether a permanent tolerance for these uses would be appropriate. Under these circumstances, EPA does not believe that these tolerances serve as a basis for registration of quinoxyfen by a State for special local needs under FIFRA section 24(c). Nor do these tolerances serve as the basis for any State other than New York to use this pesticide on these crops under section 18 of FIFRA without following all provisions of EPA's regulations implementing FIFRA section 18 as identified in 40 CFR part 166. For additional information regarding the emergency exemption for quinoxyfen, contact the Agency's Registration Division at the address provided under FOR FURTHER INFORMATION CONTACT.

4. Aggregate Risk Assessment and Determination of Safety

   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 the final rule on Bifenthrin Pesticide Tolerances (62 FR 62961, November 26, 1997) (FRL- 5754-7).

   Consistent with section 408(b)(2)(D) of the 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 quinoxyfen and to make a determination on aggregate exposure, consistent with section 408(b)(2) of the FFDCA, for a time-limited tolerance for residues of quinoxyfen in or on vegetable, cucurbit, subgroup 9A; pumpkin; and squash, winter at 0.30 ppm. EPA's assessment of the dietary exposures and risks associated with establishing the tolerance follows.

   1. Toxicological Endpoints

      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. The toxicology database for quinoxyfen is complete. EPA has considered available information concerning the variability of the sensitivities of major identifiable

      [[Page 4028]]

      subgroups of consumers, including infants and children. The nature of the toxic effects caused by quinoxyfen are fully discussed in a Federal Register Notice published on September 29, 2003 (68 FR 55849) that established tolerances for residues of quinoxyfen on cherries, grapes and hops. Please refer to that document for a complete discussion of the no observed adverse effect level (NOAEL) and the lowest observed adverse effect level (LOAEL) from the toxicity studies reviewed.

      The dose, typically the NOAEL, from the toxicology study identified as appropriate for use in risk assessment is used to estimate the toxicological endpoint. However, the lowest dose at which adverse effects of concern are identified 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. An UF of 100 is routinely used, 10X to account for interspecies differences and 10X for intraspecies differences.

      For dietary risk assessment (other than cancer) the Agency uses the UF to calculate an acute or chronic reference dose (acute RfD or chronic RfD) where the RfD is equal to the NOAEL divided by the appropriate UF (RfD = NOAEL/UF). Where an additional safety factor (SF) is retained due to concerns unique to the FQPA, this additional factor is applied to the RfD by dividing the RfD by such additional factor. The acute or chronic Population Adjusted Dose (aPAD or cPAD) is a modification of the RfD to accommodate this type of FQPA SF.

      For non-dietary risk assessments (other than cancer) the UF is used to determine the level of concern (LOC). For example, when 100 is the appropriate UF (10X to account for interspecies differences and 10X for intraspecies differences) the LOC is 100. To estimate risk, a ratio of the NOAEL to exposures (margin of exposure (MOE) = NOAEL/exposure) is calculated and compared to the LOC.

      The linear default risk methodology (Q*) is the primary method currently used by the Agency to quantify carcinogenic risk. The Q* approach assumes that any amount of exposure will lead to some degree of cancer risk. A Q* is calculated and used to estimate risk which represents a probability of occurrence of additional cancer cases (e.g., risk is expressed as 1 x10-6or one in a million). Under certain specific circumstances, MOE calculations will be used for the carcinogenic risk assessment. In thisnon-linear approach, a ``point of departure'' is identified below which carcinogenic effects are not expected. The point of departure is typically a NOAEL based on an endpoint related to cancer effects though it may be a different value derived from the dose response curve. To estimate risk, a ratio of the point of departure to exposure (MOEcancer= point of departure/exposures) is calculated. A summary of the toxicological endpoints for Quinoxyfen used for human risk assessment is shown in the following Table 1:

      Table 1.--Summary of Toxicological Dose and Endpoints for Quinoxyfen for Use in Human Risk Assessment

      FQPA SF* and Level of Exposure Scenario

      Dose Used in Risk Concern for Risk Study and Toxicological Assessment, UF

      Assessment

      Effects

      Acute dietary (females 13-50 years Not applicable

      Not applicable

      There were no toxic effects of age) and Acute dietary (general

      attributable to a single population including infants and

      dose.Therefore, an endpoint children)

      of concern was not identified to quantitateacute-dietary risk to the general population or to the subpopulationfemales 13-50 years old

      Chronic Dietary (All populations) NOAEL = 20 milligram/ FQPA SF = 1cPAD =

      Combined chronic toxicity/ kilogram/day (mg/kg/ chronic RfD/FQPA SF = carcinogenicity study in rat day)UF = 100

      0.20 mg/kg/day.

      LOAEL = 80 mg/kg/day, based Chronic RfD = 0.20 mg/

      upon increases in severity kg/day.

      ofchronic progressive glomerulonephropathy in the males and minimal decreasesin body weight and body weightgain in both sexes

      Cancer (oral, dermal, inhalation) classified as not Not applicable

      No evidence of likely to be

      carcinogenicity in rats and carcinogenic to

      mice humans

      \*\The reference to the FQPA SF refers to any additional SF retained due to concerns unique to the FQPA.

   2. Exposure Assessment

      1. Dietary exposure from food and feed uses. Tolerances have been established (40 CFR 180.588) for the residues of quinoxyfen, in or on a variety of raw agricultural commodities including sweet and tart cherries, hops and grapes. Risk assessments were conducted by EPA to assess dietary exposures from quinoxyfen in food as follows:

         i. Acute exposure. Quantitative 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 one day or single exposure. There were no toxic effects attributable to a single dose. Therefore, an endpoint of concern was not identified to quantitate acute-dietary risk to the general population or to the subpopulation females 13-50 years old. As a result, no acute risk is expected from exposure to quinoxyfen and hence no quantitative acute dietary risk assessment was performed.

         ii. Chronic exposure. In conducting this chronic dietary risk assessment EPA used the Dietary Exposure Evaluation Model software with the Food Commodity Intake Database (DEEM-FCID\TM\ ) which incorporates food consumption data as reported by respondents in the USDA 1994-1996

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         and 1998 nationwide Continuing Surveys of Food Intake by Individuals (CSFII) and accumulated exposure to the chemical for each commodity. The following assumptions were made: An unrefined, Tier 1 chronic- dietary exposure assessment using tolerance-level residues and assuming 100% CT for all proposed commodities, and default DEEM Version 7.76 processing factors for all commodities.

         iii. Cancer. Quinoxyfen has been classified as not likely to be carcinogenic to humans. Therefore, a quantitative exposure assessment was not conducted to assess cancer risk.

      2. Dietary exposure from drinking water. The Agency lacks sufficient monitoring exposure data to complete a comprehensive dietary exposure analysis and risk assessment for quinoxyfen in drinking water. Because the Agency does not have comprehensive monitoring data, drinking water concentration estimates are made by reliance on simulation or modeling taking into account data on the physical characteristics of quinoxyfen.

         The Agency uses the First Index Reservoir Screening Tool (FIRST) or the Pesticide Root Zone/Exposure Analysis Modeling System (PRZM/EXAMS) to produce estimates of pesticide concentrations in an index reservoir. The Screening Concentrations in Groundwater (SCI-GROW) model is used to predict pesticide concentrations in shallow ground water. For a screening-level assessment for surface water EPA will generally use FIRST (a Tier 1 model) before using PRZM/EXAMS (a Tier 2 model). The FIRST model is a subset of the PRZM/EXAMS model that uses a specific high-end runoff scenario for pesticides. While both FIRST and PRZM/ EXAMS incorporate an index reservoir environment, the PRZM/EXAMS model includes a percent crop area factor as an adjustment to account for the maximum percent crop coverage within a watershed or drainage basin.

         None of these models include consideration of the impact processing (mixing, dilution, or treatment) of raw water for distribution as drinking water would likely have on the removal of pesticides from the source water. The primary use of these models by the Agency at this stage is to provide a coarse screen for sorting out pesticides for which it is highly unlikely that drinking water concentrations would ever exceed human health levels of concern.

         Since the models used are considered to be screening tools in the risk assessment process, the Agency does not use estimated environmental concentrations (EECs) from these models to quantify drinking water exposure and risk as a %RfD or %PAD. Instead drinking water levels of comparison (DWLOCs) are calculated and used as a point of comparison against the model estimates of a pesticide's concentration in water. DWLOCs are theoretical upper limits on a pesticide's concentration in drinking water in light of total aggregate exposure to a pesticide in food, and from residential uses. Since DWLOCs address total aggregate exposure to quinoxyfen they are further discussed in the aggregate risk sections below.

         Based on the FIRST and SCI-GROW models the EECs of quinoxyfen for chronic exposures are estimated to be 0.8 parts per billion (ppb) for surface water and 0.006 ppb for ground 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). Quinoxyfen is not registered for use on any sites that would result in residential exposure.

      4. Cumulative exposure to substances with a common mechanism oftoxicity. Section 408(b)(2)(D)(v) of the FFDCA requires that, when considering whether to establish, modify, or revoke a tolerance, the Agency consider ``available information'' concerning the cumulative effects of a particular pesticide's residues and ``other substances that have a common mechanism of toxicity.''

         EPA does not have, at this time, available data to determine whether quinoxyfen 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, quinoxyfen 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 quinoxyfen 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).

   3. Safety Factor for Infants and Children

      1. In general. Section 408 of the FFDCA provides that EPA shall apply an additional tenfold 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 data base on toxicity and exposure 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 MOE analysis or through using uncertainty (safety) factors in calculating a dose level that poses no appreciable risk to humans.

      2. Developmental toxicity studies. In a prenatal developmental study in rats the Maternal and Developmental NOAELs were 1,000 mg/kg/ day and no LOAELs were identified. In a prenatal developmental study in rabbits the Maternal NOAEL was 80 mg/kg/day and the LOAEL was 200 mg/ kg/day based on inanition, clinical signs, decreased body weights, body weight gains, and food consumption and on increased incidences of abortion. The Developmental NOAEL is 80 mg/kg/day and the LOAEL is 200 mg/kg/day based on increased incidences of abortion.

      3. Reproductive toxicity study. In a reproduction toxicity study in rats the Parental/Systemic NOAEL was 100 mg/kg/day and no LOAEL was identified. The Reproductive NOAEL was 100 mg/kg/day and no LOAEL was identified. The Offspring NOAEL was 20 mg/kg/day and the LOAEL was 100 mg/kg/day based on a minimal decrease in F1apup weights.

      4. Prenatal and postnatal sensitivity. There is no quantitative or qualitative evidence of increased susceptibility of rat and rabbit fetuses to in utero exposure in developmental studies. There is evidence of increased quantitative susceptibility (minimal decrease in F1apup weights) in the rat multi-generation reproduction study, but the concern is low since: (1) The effects in pups are well- characterized with a clear NOAEL; (2) the pup effects are minimal at the LOAEL and only noted in the first-generation offspring; and, (3) the doses and endpoints selected for regulatory purposes would address the concerns of the pup effects noted in the rat reproduction study. Therefore, there are no residual uncertainties for prenatal/postnatal toxicity in this study.

      5. Conclusion. There is a complete toxicity data base for quinoxyfen and exposure data are complete or are estimated based on data that reasonably

      [[Page 4030]]

      accounts for potential exposures. There are no residual uncertainties for prenatal/postnatal toxicity. No additional safety factor is needed for database uncertainties. No clinical sign of neurotoxicity or neuropathology was seen in the data base. A developmental neurotoxicity study is not required. Therefore, EPA determined that the 10X SF to protect infants and children should be reduced to 1X.

   4. Aggregate Risks and Determination of Safety

      To estimate total aggregate exposure to a pesticide from food, drinking water, and residential uses, the Agency calculates DWLOCs which are used as a point of comparison against the model estimates of a pesticide's concentration in water (EECs). DWLOC values are not regulatory standards for drinking water. DWLOCs are theoretical upper limits on a pesticide's concentration in drinking water in light of total aggregate exposure to a pesticide in food and residential uses. In calculating a DWLOC, the Agency determines how much of the acceptable exposure (i.e., the PAD) is available for exposure through drinking water e.g., allowable chronic water exposure (mg/kg/day) = cPAD - (average food + chronic non-dietary, non-occupational exposure). This allowable exposure through drinking water is used to calculate a DWLOC.

      A DWLOC will vary depending on the toxic endpoint, drinking water consumption, and body weights. Default body weights and consumption values as used by the USEPA Office of Water are used to calculate DWLOCs: 2 liter (L)/70 kg (adult male), 2L/60 kg (adult female), and 1L/10 kg (child). Default body weights and drinking water consumption values vary on an individual basis. This variation will be taken into account in more refined screening-level and quantitative drinking water exposure assessments. Different populations will have different DWLOCs. Generally, a DWLOC is calculated for each type of risk assessment used: Acute, short-term, intermediate-term, chronic, and cancer.

      When EECs for surface water and groundwater are less than the calculated DWLOCs, OPP concludes with reasonable certainty that exposures to quinoxyfen in drinking water (when considered along with other sources of exposure for which OPP has reliable data) would not result in unacceptable levels of aggregate human health risk at this time. Because OPP considers the aggregate risk resulting from multiple exposure pathways associated with a pesticide's uses, levels of comparison in drinking water may vary as those uses change. If new uses are added in the future, OPP will reassess the potential impacts of quinoxyfen on drinking water as a part of the aggregate risk assessment process.

      1. Acute risk. An endpoint of concern was not identified to quantitate acute-dietary risk to the general population or to the subpopulation females 13-50 years old. As a result, no acute risk is expected from exposure to quinoxyfen.

      2. Chronic risk. Using the exposure assumptions described in this unit for chronic exposure, EPA has concluded that exposure to quinoxyfen from food will utilize less than 1% of the cPAD for the U.S. population, 1% of the cPAD for all infants (