Pesticides; tolerances in food, animal feeds, and raw agricultural commodities: S-metolachlor,

[Federal Register: August 30, 2006 (Volume 71, Number 168)]

[Rules and Regulations]

[Page 51505-51510]

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

[DOCID:fr30au06-19]

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[EPA-HQ-OPP-2006-0292; FRL-8090-2]

S-metolachlor; Pesticide Tolerance

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

SUMMARY: This regulation establishes tolerances for combined residues of S-metolachlor in or on pumpkin, and squash, winter. Interregional Research Project Number 4 (IR-4) requested these tolerances under the Federal Food, Drug, and Cosmetic Act (FFDCA), as amended by the Food Quality Protection Act of 1996 (FQPA).

DATES: This regulation is effective August 30, 2006. Objections and requests for hearings must be received on or before October 30, 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-2006-0292. 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 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 Docket telephone number is (703) 305-5805.

FOR FURTHER INFORMATION CONTACT: Shaja R. Brothers, Registration Division (7505P), Office of Pesticide Programs, Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460- 0001; telephone number: (703) 308-3194; e-mail address: brothers.shaja@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.gpo/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-2006-0292 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 October 30, 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

      [[Page 51506]]

      EPA-HQ-OPP-2006-0292, 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 Docket telephone number is (703) 305-5805.

2. Background and Statutory Findings

   In the Federal Register of April 21, 2006 71 FR 20663 FRL-8064-6, 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 5E7015) by IR-4, 681 Highway 1 South, North Brunswick, NJ 08902-3390. The petition requested that 40 CFR 180.368(a)(3) be amended by establishing tolerances for combined residues of the herbicide S-metolachlor, S-2- chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1- methylethyl)acetamide], its R-enantiomer, and its metabolites, determined as the derivatives, 2-[2-ethyl-6-methylphenyl)amino]-1- propanol and 4-(2-ethyl-6-methylphenyl)-2-hydroxy-5-methyl-3- morpholinone, in or on pumpkin and squash, winter at 1.0 part per million (ppm), respectively. The tolerances were subsequently amended to 0.1 ppm for raw agricultural commodities previously mentioned. This notice included a summary of the petition prepared by Syngenta, the registrant. There were no comments received in response to the notice of filing.

   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....''

   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 tolerances for combined residues of S- metolachlor on pumpkin at 0.1 ppm, and squash, winter at 0.1 ppm. EPA's assessment of exposure and risk associated with establishing the tolerances 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. Specific information on the studies received and the nature of the toxic effects caused by metolachlor and S-metolachlor 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 (Docket No. EPA-HQ-OPP- 2006-0292-0003; pages 53-

      64).

   2. Toxicological Endpoints

      For hazards that have a threshold below which there is no appreciable risk, the dose at which no adverse effects are observed (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 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.

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

      A summary of the toxicological endpoints for metolachlor and S- metolachlor used for human risk assessment is discussed at http://www.regulations.gov (Docket No. EPA-HQ-OPP-2006-0292; pages 20-21).

   3. Exposure Assessment

      1. Dietary exposure from food and feed uses. Tolerances have been established (40 CFR 180.368) for the combined residues of S- metolachlor, in or on a variety of raw agricultural commodities. Meat, milk, poultry and egg tolerances have also been established. Risk assessments were conducted by EPA to assess dietary exposures from S- metolachlor in food as follows:

         Both the acute and chronic analyses assume tolerance-level residues on all crops with established, pending, or proposed tolerances for metolachlor and/or S-metolachlor. In cases where separate tolerance listings occur for both metolachlor and S-metolachlor on the same commodity, the higher value of the two is used in the analyses.

         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 one-day or single exposure. In conducting the acute dietary exposure 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 and 1998 Nationwide Continuing Surveys of Food Intake by Individuals (CSFII), and accumulated

         [[Page 51507]]

         exposure to the chemical for each commodity. The following assumptions were made for the acute exposure assessments: An acute dietary analysis for S-metolachlor was conducted using tolerance level residues and 100 % crop treated (CT) for all existing and proposed uses.

         ii. Chronic exposure. In conducting the chronic dietary exposure 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 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 for the chronic exposure assessments: A chronic dietary analysis for S-metolachlor was conducted using tolerance level residues and 100 %CT data for all existing and proposed uses.

         iii. Cancer. Metolachlor has been classified as a Group C, possible human carcinogen based on liver tumors in rats at the highest dose tested (HDT). The chronic NOAEL of 15 mg/kg/day that was established based on tumors in the rat (seen at the HDT of 150 mg/kg/day) is comparable to the NOAEL of 9.7 mg/kg/day selected for establishing the chronic reference dose for metolachlor. EPA has concluded that the chronic dietary PAD is protective for cancer dietary risk. Therefore, a separate cancer aggregate risk assessment was not conducted.

      2. Dietary exposure from drinking water. The Agency lacks sufficient monitoring exposure data to complete a comprehensive dietary exposure analysis and risk assessment for s-metolachlor 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 s-metolachor. 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.

         A drinking water assessment was conducted based on monitoring data from several sources, as well as on Tier 1 FIRST and SCI-GROW modeling results. This assessment is a worst-case scenario and demonstrates high end numbers. The analytical methods used to obtain the monitoring data are not able to distinguish between metolachlor and S-metolachlor; therefore, the estimated environmental concentrations (EECs) presented in this risk assessment are representative of both racemic metolachlor and S-metolachlor.

         EECs for metolachlor and S-metolachlor were calculated for both the parent compound and the ethanesulfonic acid (ESA) and oxanilic acid (OA) degradates. Although it was determined by the EPA that the ESA and OA metabolites appear to be less toxic than parent metolachlor, they are included in the risk assessment since they were found in greater abundance than the parent in water monitoring studies.

         The crops with the highest maximum seasonal application rates are turf (S-metolachlor only) and corn (racemic metolachlor and S- metolachlor) with a maximum seasonal application rate of 4.0 lbs ai/A. Based on PRZM/EXAMS modeling the maximum peak and annual average concentrations of metolachlor/ S-metolachlor in surface water were 199 ug/l and 9.2 ug/l, respectively. Based on FIRST modeling results, the estimate of the drinking water concentration from surface water sources of metolachlor ESA, a major degradate of metolachlor, is not likely to exceed 31.9 ug/L for the annual peak concentration and 22.8 ug/L for the annual average exposure for use on turf/corn at a maximum annual application rate of 4.0 lbs ai/A. Based on FIRST modeling results, the estimate of the drinking water concentration from surface water sources of metolachlor OA, another major degradate of metolachlor, is not likely to exceed 91.4 ug/L for the annual peak concentration and 65.1 ug/L for the annual average exposure for use on turf/corn at a maximum annual application rate of 4.0 lbs ai/A (ground application with no spray drift).

         The SCI-GROW screening model was used to estimate groundwater concentrations. The estimated concentration of metolachlor/ S- metolachlor in drinking water from shallow groundwater sources is 5.5 ug/l for application on corn at a seasonal maximum rate of 4.0 lbs ai/ A. This concentration is appropriate for both the peak and annual average exposures. The EEC for metolachlor degradate ESA based on metolachlor use on turf/corn is not expected to exceed 65.8 ug/l for peak and annual average exposures. The EEC for metolachlor OA from metolachlor use on turf/corn is not expected to exceed 31.7 ug/l for peak and annual average exposures.

         Table 1: Metolachlor EEC's

         Surface Water (peak) Surface Water (average)

         Ground Water

         Parent

         199

         9.2

         5.5

         metolachlor ESA

         31.9

         22.8

         65.8

         metolachlor OA

         91.4

         65.1

         31.7

         Total EECs (ppb)

         322.3

         97.1

         103.0

         Modeled estimates of drinking water concentrations were directly entered into the dietary exposure model (DEEM-FCID\TM\). For acute dietary risk, since the surface water EDWCs are higher than the groundwater EDWC, the peak concentration of 322.3 ppb was used to access the contribution to drinking water. For chronic dietary risk assessment, since the ground water EDWCs are higher than the surface water EDWC the ground water concentration of 103.0 ppb was used to access 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).

         The formulated S-metolachlor end-use product is labeled under the trade name Pennant MAGNUM\TM\ (EPA Reg. No. 100-950) to distinguish the new product from the original metolachlor formulation named Pennant\TM\ (EPA Reg. No. 100-691). Pennant MAGNUM\TM\ (7.62 lbs. active ingredient per gallon) is labeled for use on commercial (sod farm) and residential warm-season turfgrasses and other

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         noncrop land including golf courses, sports fields, and ornamental gardens. Although not labeled as a restricted-use pesticide, Pennant MAGNUM\TM\, as currently marketed, is not intended for homeowner purchase or use (intended for use by professionals). On this basis, with regard to the requirements of FQPA, metolachlor and S-metolachlor are assessed only for post application exposure and risk. Pennant MAGNUM\TM\ and Pennant\TM\ are both emulsifiable concentrates (EC).

         For this risk assessment, small children are the population group of concern. Although the type of site that S-metolachlor may be used on varies from golf courses to ornamental gardens, the scenario chosen for risk assessment (residential turf use) represents what the Agency considers the likely upper-end of possible exposure. Post application exposures from various activities following lawn treatment are considered to be the most common and significant in residential settings. Since toxicity was not observed in a dermal toxicity study, up to a dose level of 1,000 mg/kg/day, the only parameter of risk addressed in this assessment is the possible oral exposure of small children from treated turf, or soil.

         The estimate for hand-to-mouth exposure on the day of treatment is 0.037 mg/kg/day (MOE = 1,400) for S-metolachlor and 0.06 mg/kg/day (MOE = 840) for metolachlor. (MOE estimates are based on the short-term NOAEL of 50 mg/kg/day).

         The estimate for object-to-mouth exposure on the day of treatment is 0.0092 mg/kg/day (MOE = 5,400) for S-metolachlor and 0.015 mg/kg/day (MOE = 3,300) for metolachlor. (MOE estimates are based on the short- term NOAEL of 50 mg/kg/day).

         The estimate for soil ingestion exposure on the day of treatment is 0.00012 mg/kg/day (MOE = 400,000) for S-metolachlor and 0.0002 mg/kg/ day (MOE = 250,000) for metolachlor. (MOE estimates are based on the short-term NOAEL of 50 mg/kg/day).

         The estimate for hand-to-mouth, object-to-mouth, and soil ingestion combined (on the day of treatment) is 0.046 mg/kg/day (MOE = 1,100) for S-metolachlor and 0.075 mg/kg/day (MOE = 670) for metolachlor. (MOE estimates are based on the short-term NOAEL of 50 mg/kg/day).

         The MOE estimates are greater than 100 and indicate that the potential metolachlor/S-metolachlor exposure (to children) associated with residential use is not of concern. Although considered an upper- bound, the exposure estimate for the three scenarios, combined, is recommended for aggregate (residential, food, and drinking water) risk estimates.

      4. Cumulative effects from substances with a common mechanism of toxicity. 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.''

         Unlike other pesticides for which EPA has followed a cumulative risk approach based on a common mechanism of toxicity, EPA has not made a common mechanism of toxicity finding as to S-metolachlor and any other substances and S-metolachlor 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 S-metolachlor 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 policy statements released by EPA's Office of Pesticide Programs concerning common mechanism determinations and procedures for cumulating effects from substances found to have a common mechanism on EPA's website at http://www.epa.gov/pesticides/cumulative .

   4. Safety Factor for Infants and Children

      1. In general. Section 408 of 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 based on reliable data 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. In applying this provision, EPA either retains the default value of 10X when reliable data do not support the choice of a different factor, or, if reliable data are available, EPA uses a different additional safety factor value based on the use of traditional uncertainty factors and/or special FQPA safety factors, as appropriate.

      2. Prenatal and postnatal sensitivity--i. Metolachlor. The prenatal developmental studies in the rat and rabbit revealed no evidence of a qualitative or quantitative susceptibility in fetal animals. In the rabbit prenatal developmental toxicity study, at 360 mg/kg/day, maternal animals had persistent anorexia and decreased body weight gain; the NOAEL was 120 mg/kg/day. In the rat prenatal developmental toxicity study, frank toxicity [death, clinical signs (clonic and/or tonic convulsions, excessive salivation, urine-stained abdominal fur and/or excessive salivation) and decreased body weight gain] was observed at the limit dose of 1,000 mg/kg/day in maternal animals; the NOAEL was 300 mg/kg/day. The developmental effects at 1,000 mg/kg/day included slightly decreased number of implantations per dam, decreased number of live fetuses/dam, increased number of resorptions/dam and significant decrease in mean fetal body weight.

         In the two-generation reproduction study in rats, there was no evidence of parental or reproductive toxicity at approximately 80 mg/ kg/day, the HDT. At this dose, there was a minor decrease in fetal body weight beginning at lactation day 4; the NOAEL was approximately 25 mg/ kg/day. Since a similar body weight decrease was not seen on lactation day zero, the cause of the effect on later lactation days is most likely due to exposure of the pups to metolachlor in the diet and/or milk and therefore is not evidence of an increased quantitative susceptibility in post-natal animals.

         ii. S-metolachlor. There was no evidence of increased quantitative or qualitative fetal susceptibility in the prenatal developmental studies in rats and rabbits. In the rat, maternal toxicity [increased clinical signs of toxicity (pushing head through bedding) and decreased body weights/body weight gains, food consumption and food efficiency was observed at 500 mg/kg/day; the NOAEL was 50 mg/kg/day. There were no developmental effects at 1,000 mg/kg/day, the HDT. In the rabbit, clinical signs of toxicity (little/none/soft stool) were observed at 100 mg/kg/day; the NOAEL was 20 mg/kg/day. No developmental effects were observed at 500 mg/kg/day, the HDT.

      3. Conclusion. There is a complete toxicity data base for S- metolachlor and exposure data are complete or are estimated based on data that reasonably accounts for potential exposures. EPA determined that the 10X SF to protect infants and children should be reduced to 1X for the following reasons:

         i. The toxicology database is complete for the FQPA assessment.

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         ii. There is no indication of quantitative or qualitative increased susceptibility of rats or rabbits to in utero and/or postnatal exposure to metolachlor or S-metolachlor in the available toxicity data.

         iii. A developmental neurotoxicity study is not required for metolachlor or S-metolachlor.

         iv. The dietary (food and drinking water) and non-dietary exposure (residential) assessments will not underestimate the potential exposures for infants and children from the use of metolachlor or S- metolachlor.

   5. Aggregate Risks and Determination of Safety

      1. Acute risk. Using the exposure assumptions discussed in this unit for acute exposure, the acute dietary exposure from food and water to S-metolachlor will occupy