Mesotrione; Pesticide Tolerance, 9222-9226 [E8-3123]

Download as PDF 9222 Federal Register / Vol. 73, No. 34 / Wednesday, February 20, 2008 / Rules and Regulations 40 CFR Part 180 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: Erik Kraft, Registration Division (7505P), Office of Pesticide Programs, Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460–0001; telephone number: (703) 308–9358; e-mail address: kraft.erik @epa.gov. SUPPLEMENTARY INFORMATION: [EPA–HQ–OPP–2007–0030; FRL–8349–7] I. General Information Mesotrione; Pesticide Tolerance A. Does this Action Apply to Me? Environmental Protection Agency (EPA). ACTION: Final rule. 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), e.g., agricultural workers; greenhouse, nursery, and floriculture workers; farmers. • Animal production (NAICS code 112), e.g., cattle ranchers and farmers, dairy cattle farmers, livestock farmers. • Food manufacturing (NAICS code 311), e.g., agricultural workers; farmers; greenhouse, nursery, and floriculture workers; ranchers; pesticide applicators. • Pesticide manufacturing (NAICS code 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 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. Commodity * * Parts per million * * Sorghum, grain ............... * * * * * Soybean, seed ................ * * * * * Sugarcane ...................... * * * * * Wheat, Wheat, Wheat, Wheat, Wheat, * * 0.25 0.10 0.15 bran .................... flour .................... germ ................... middlings ............ shorts ................. * * * 0.80 0.80 0.80 0.80 0.80 * [FR Doc. E8–3111 Filed 2–19–08; 8:45 am] BILLING CODE 6560–50–S ENVIRONMENTAL PROTECTION AGENCY sroberts on PROD1PC70 with RULES AGENCY: SUMMARY: This regulation establishes tolerances for residues of mesotrione in or on asparagus, grass grown for seed, oats, okra, rhubarb, grain sorghum, sweet sorghum, and sugarcane. Syngenta Crop Protection requested this tolerance under the Federal Food, Drug, and Cosmetic Act (FFDCA). DATES: This regulation is effective February 20, 2008. Objections and requests for hearings must be received on or before April 21, 2008, 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–2007–0030. To access the electronic docket, go to http:// www.regulations.gov, select ‘‘Advanced Search,’’ then ‘‘Docket Search.’’ Insert the docket ID number where indicated and select the ‘‘Submit’’ button. Follow the instructions on the regulations.gov website to view the docket index or access available documents. All documents in the docket are listed in the docket index available in regulations.gov. Although listed in the index, some information is not publicly available, e.g., Confidential Business Information (CBI) or other information VerDate Aug<31>2005 15:54 Feb 19, 2008 Jkt 214001 PO 00000 Frm 00052 Fmt 4700 Sfmt 4700 B. 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 EPA’s tolerance regulations at 40 CFR part 180 through the Government Printing Office’s pilot e-CFR site at http://www.gpoaccess.gov/ ecfr. C. Can I File an Objection or Hearing Request? Under section 408(g) of FFDCA, 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–2007–0030 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 as required by 40 CFR part 178 on or before April 21, 2008. In addition to filing an objection or hearing request with the Hearing Clerk as described in 40 CFR part 178, please submit a copy of the filing that does not contain any CBI for inclusion in the public docket that is described in ADDRESSES. Information not marked confidential pursuant to 40 CFR part 2 may be disclosed publicly by EPA without prior notice. Submit this copy, identified by docket ID number EPA– HQ–OPP–2007–0030, 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’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 Facility telephone number is (703) 305–5805. E:\FR\FM\20FER1.SGM 20FER1 Federal Register / Vol. 73, No. 34 / Wednesday, February 20, 2008 / Rules and Regulations II. Petition for Tolerance In the Federal Register of April 25, 2006 (71 FR 24695) (FRL–8063–7), EPA issued a notice pursuant to section 408(d)(3) of FFDCA, 21 U.S.C. 346a(d)(3), announcing the filing of a pesticide petition (PP 6F7023) by Syngenta Crop Protection, P.O. Box 18300, Greensboro, NC. The petition requested that 40 CFR 180.571 be amended by establishing tolerances for residues of the herbicide mesotrione, 2[4- (methylsulfonyl)-2-nitrobenzoyl]-1,3cyclohexanedione, in or on commodity asparagus at 0.01 parts per million (ppm); grass, seed screenings at 0.10 ppm; grass, straw at 0.10 ppm; grass, forage at 0.01 ppm; grass, hay at 0.01 ppm; oats, grain, oats, straw at 0.01 ppm; oats, forage at 0.1 ppm; oats, hay at 0.01 ppm; okra at 0.01 ppm; rhubarb at 0.01 ppm; sorghum, forage at 0.01 ppm; sorghum, stover at 0.01 ppm; sorghum, grain at 0.01 ppm; sorghum, sweet at 0.01 ppm; and sugarcane at 0.01 ppm. That notice referenced a summary of the petition prepared by Syngenta Crop Protection, the registrant, which is available to the public in the docket, http://www.regulations.gov. There were no comments received in response to the notice of filing. Based upon review of the data supporting the petition, to harmonize with the Food and Feed Commodity Vocabulary http://www.epa.gov/ opphed01/foodfeed/index.htm. EPA has amended the commodity listing to read: Asparagus at 0.01 ppm; grass, seed screenings at 0.10 ppm; grass, straw at 0.10 ppm; grass, forage at 0.01 ppm; grass, hay at 0.01 ppm; oat, grain at 0.01 ppm; oat, straw at 0.01 ppm; oat, forage at 0.01 ppm; oat, hay at 0.01 ppm; okra at 0.01 ppm; rhubarb at 0.01 ppm; sorghum, grain, forage at 0.01 ppm; sorghum, grain, grain at 0.01 ppm; sorghum, grain, stover at 0.01 ppm; sorghum, sweet at 0.01 ppm and sugarcane, cane at 0.01 ppm. sroberts on PROD1PC70 with RULES III. 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 VerDate Aug<31>2005 15:54 Feb 19, 2008 Jkt 214001 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.’’ These provisions were added to FFDCA by the Food Quality Protection Act (FQPA) of 1996. Consistent with FFDCA section 408(b)(2)(D), and the factors specified in FFDCA section 408(b)(2)(D), 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 the petitioned-for tolerance for residues of mesotrione on asparagus at 0.01 ppm; grass, seed screenings at 0.10 ppm; grass, straw at 0.10 ppm; grass, forage at 0.01 ppm; grass, hay at 0.01 ppm; oat, grain at 0.01 ppm; oat, straw at 0.01 ppm; oat, forage at 0.01 ppm; oat, hay at 0.01 ppm; okra at 0.01 ppm; rhubarb at 0.01 ppm; sorghum, grain, forage at 0.01 ppm; sorghum, grain, grain at 0.01 ppm; sorghum, grain, stover at 0.01 ppm; sorghum, sweet at 0.01 ppm and sugarcane, cane at 0.01 ppm. EPA’s assessment of exposures and risks associated with establishing the tolerance follows. A. 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. Mesotrione has low acute toxicity via the oral, dermal, and inhalation routes. It is a mild eye irritant, but is not a dermal irritant or a dermal sensitizer. In subchronic and chronic oral studies, ocular lesions, liver and kidney effects, and/or body weight decrements were the major adverse effects seen in the rat, mouse, and dog. Plasma tyrosine levels were increased in the rat, mouse and dog in the chronic and reproduction studies in which levels were measured. The ocular, liver and kidney effects are believed to be mediated by the high tyrosine levels in the blood caused by inhibition of the enzyme HPPD. Even though the rat is the most sensitive species to this effect compared to the dog and the mouse, EPA concluded that the mouse is a more appropriate model PO 00000 Frm 00053 Fmt 4700 Sfmt 4700 9223 for assessing human risk than is the rat. There was no evidence of carcinogenic potential in either the rat chronic toxicity/carcinogenicity or mouse carcinogenicity studies and no concern for mutagenicity. No evidence of neurotoxicity or neuropathology was seen in the acute and subchronic neurotoxicity studies. In the multigeneration mouse reproduction study, one first generation male and one first generation female had retinal detachment with marked cataractous changes at the highest dose tested (>1000 milligrams/kilograms/day (mg/ kg/day). In the subchronic toxicity dog study, the high-dose females had decreased absolute and relative brain weights; however, no microscopic abnormalities were noted in any brain tissues from the high-dose group and effect was not observed in the chronic toxicity dog study. Therefore, there is some concern about the effects of elevated plasma tyrosine levels on the developing nervous system in children due to a report that some patients with tyrosinemia III (an autosomal recessive disorder in which HPPD is deficient) were presented with mental retardation or neurological symptoms. There was evidence of increased susceptibility of rats, mice and rabbits to in utero and/ or post-natal exposure to mesotrione. Specific information on the studies received and the nature of the adverse effects caused by mesotrione as well as the no-observed-adverse-effect-level (NOAEL) and the lowest-observedadverse-effect-level (LOAEL) from the toxicity studies can be found at http:// www.regulations.gov. The referenced document is available in the docket established by this action, which is described under ADDRESSES, and is identified as ‘‘Petition#: 6F7162. Mesotrione: Human Health Risk Assessment for Proposed Section 3 New Uses on Asparagus, Grasses Grown for Seed, Oats, Okra, Rhubarb, Sugarcane, Grain Sorghum, Sweet Sorghum and Turf (Golf Course and Sod Farms)’’ in that docket. Additionally, mesotrione toxicological data are discussed in the final rule published in the Federal Register of June 21, 2001 (66 FR 33187) (FRL–6787–7). B. Toxicological Endpoints For hazards that have a threshold below which there is no appreciable risk, the toxicological level of concern (LOC) is derived from the highest dose at which no adverse effects are observed (the NOAEL) in the toxicology study identified as appropriate for use in risk assessment. However, if a NOAEL cannot be determined, the lowest dose at which adverse effects of concern are E:\FR\FM\20FER1.SGM 20FER1 9224 Federal Register / Vol. 73, No. 34 / Wednesday, February 20, 2008 / Rules and Regulations identified (the LOAEL) is sometimes used for risk assessment. Uncertainty/ safety factors (UFs) are used in conjunction with the LOC to take into account 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. Safety is assessed for acute and chronic risks by comparing aggregate exposure to the pesticide to the acute population adjusted dose (aPAD) and chronic population adjusted dose (cPAD). The aPAD and cPAD are calculated by dividing the LOC by all applicable UFs. Short-, intermediate-, and long-term risks are evaluated by comparing aggregate exposure to the LOC to ensure that the margin of exposure (MOE) called for by the product of all applicable UFs is not exceeded. For non-threshold risks, the Agency assumes that any amount of exposure will lead to some degree of risk and estimates risk in terms of the probability of occurrence of additional adverse cases. Generally, cancer risks are considered non-threshold. 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/fedrgstr/EPA-PEST/1997/ November/Day-26/p30948.htm. A summary of the toxicological endpoints for mesotrione used for human risk assessment can be found at http://www.regulations.gov in document ‘‘Petition#: 6F7162. Mesotrione: Human Health Risk Assessment for Proposed Section 3 New Uses on Asparagus, Grasses Grown for Seed, Oats, Okra, Rhubarb, Sugarcane, Grain Sorghum, Sweet Sorghum and Turf (Golf Course and Sod Farms)’’ at page 15 in docket ID number EPA–HQ–OPP–2007–0030. sroberts on PROD1PC70 with RULES C. Exposure Assessment 1. Dietary exposure from food and feed uses. In evaluating dietary exposure to mesotrione, EPA considered exposure under the petitioned-for tolerances as well as all existing mesotrione tolerances in (40 CFR 180.571). EPA assessed dietary exposures from mesotrione 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 mesotrione; VerDate Aug<31>2005 15:54 Feb 19, 2008 Jkt 214001 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 Nationwide Continuing Surveys of Food Intake by Individuals (CSFII). As to residue levels in food, EPA assumed that all foods were treated for which there are proposed and established tolerances and that all the foods contain tolerance-level residues. iii. Cancer. Mesotrione was negative for carcinogenicity in feeding studies in rats and mice and was classified as ‘‘not likely’’ to be a human carcinogen. Therefore, a quantitative exposure assessment to evaluate cancer risk is unnecessary. 2. Dietary exposure from drinking water.The Agency lacks sufficient monitoring data to complete a comprehensive dietary exposure analysis and risk assessment for mesotrione 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 environmental fate characteristics of mesotrione. 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 First Index Reservoir Screening Tool (FIRST) and Screening Concentration in Ground Water (SCIGROW) models for turf grass (Golf Courses and Sod Farms), the estimated drinking water concentrations (EDWCs) of mesotrione for chronic exposures are estimated to be 4.7 parts per billion (ppb) for surface water and 0.18 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 4.7 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 nonoccupational, non-dietary exposure (e.g., for lawn and garden pest control, indoor pest control, termiticides, and flea and tick control on pets). 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 PO 00000 Frm 00054 Fmt 4700 Sfmt 4700 pesticide’s residues and ‘‘other substances that have a common mechanism of toxicity.’’ Mesotrione, pyrasulfotole, isoxaflutole and topramezone belong to a class of herbicides that inhibit the liver enzyme 4-hydroxyphenylpyruvate dioxygenase (HPPD), which is involved in the catabolism (metabolic breakdown) of tyrosine (an amino acid derived from proteins in the diet). Inhibition of HPPD can result in elevated tyrosine levels in the blood, a condition called tyrosinemia. HPPDinhibiting herbicides have been found to cause a number of toxicities in laboratory animal studies including ocular, developmental, liver and kidney effects. Of these toxicities, it is the ocular effect (corneal opacity) that is highly correlated with the elevated blood tyrosine levels. In fact, rats dosed with tyrosine alone show ocular opacities similar to those seen with HPPD inhibitors. Although the other toxicities may be associated with chemically-induced tyrosinemia, other mechanisms may also be involved. There are marked differences among species in the ocular toxicity associated with inhibition of HPPD. Ocular effects following treatment with HPPD inhibitor herbicides are seen in the rat but not in the mouse. Monkeys also seem to be recalcitrant to the ocular toxicity induced by HPPD inhibition. One explanation of this species-specific response in ocular opacity may be related to the species differences in the clearance of tyrosine. A metabolic pathway exists to remove tyrosine from the blood that involves a liver enzyme called tyrosine aminotransferase (TAT). In contrast to rats where ocular toxicity is observed following exposure to HPPD-inhibiting herbicides, mice and humans are unlikely to achieve the levels of plasma tyrosine necessary to produce ocular opacities because the activity of TAT in these species is much greater compared to rats. HPPD inhibitors (e.g., nitisinone) are used as an effective therapeutic agent to treat patients suffering from rare genetic diseases of tyrosine catabolism. Treatment starts in childhood but is often sustained throughout patient’s lifetime. The human experience indicates that a therapeutic dose (1 mg/ kg/day dose) of nitisinone has an excellent safety record in infants, children and adults and that serious adverse health outcomes have not been observed in a population followed for approximately a decade. Rarely, ocular effects are seen in patients with high plasma tyrosine levels; however, these effects are transient and can be readily reversed upon adherence to a restricted E:\FR\FM\20FER1.SGM 20FER1 Federal Register / Vol. 73, No. 34 / Wednesday, February 20, 2008 / Rules and Regulations sroberts on PROD1PC70 with RULES protein diet. This indicates that an HPPD inhibitor in and of itself cannot easily overwhelm the tyrosine-clearance mechanism in humans. Therefore, exposure to environmental residues of HPPD-inhibiting herbicides are unlikely to result in the high blood levels of tyrosine and ocular toxicity in humans due to an efficient metabolic process to handle excess tyrosine. The Agency continues to study the complex relationships between elevated tyrosine levels and biological effects in various species. Nonetheless, as a worst case scenario, EPA has assessed aggregate exposure to mesotrione based on ocular effects in rats. For similar reasons, a semi-quantitative screening cumulative assessment was conducted using the rat ocular effects and 100% crop treated information. The results of this screening analysis did not indicate a concern. In the future, assessments of HPPD-inhibiting herbicides will consider more appropriate models and cross species extrapolation methods. Therefore, EPA has not conducted cumulative risk assessment with other HPPD inhibitors. 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 website at http:// www.epa.gov/pesticides/cumulative. D. Safety Factor for Infants and Children 1.In general. Section 408 of FFDCA provides that EPA shall apply an additional (‘‘10X’’) 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 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. 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 FQPA safety factor value based on the use of traditional UFs and/or special FQPA safety factors, as appropriate. 2. Pre-natal and post-natal sensitivity. There is quantitative evidence of increased susceptibility of the young in the oral prenatal developmental toxicity studies in rats, mice, and rabbits and in the multi-generation reproduction study in mice and lack of a developmental neurotoxicity study in mice. Quantitative evidence of increased susceptibility was not demonstrated in VerDate Aug<31>2005 15:54 Feb 19, 2008 Jkt 214001 the multi-generation reproduction study in rats. However, no NOAEL was established for parental or offspring systemic toxicity. There is evidence of a qualitative increase in susceptibility since the tyrosinemia observed in the young was much more severe than that observed in the adults. 3. Conclusion. There are two deficiencies in the mesotrione toxicity database. First, a Developmental Neurotoxicity Study has been required to assess the effects on the developing nervous/ocular system from exposed to mesotrione. Second, the mouse twogeneration reproduction study, on which the Reference Dose/ Population Adjusted Dose [RfD/PAD] is based failed to identify a NOAEL. In light of this data gap, the necessity of a reliance on a LOAEL to calculate the RfD/PAD, and the quantitative and qualitative evidence of increased susceptibility of the young discussed above, EPA is raising the 10X FQPA safety factor to the value of 30X. E. Aggregate Risks and Determination of Safety Safety is assessed for acute and chronic risks by comparing aggregate exposure to the pesticide to the aPAD and cPAD. The aPAD and cPAD are calculated by dividing the LOC by all applicable UFs. For linear cancer risks, EPA calculates the probability of additional cancer cases given aggregate exposure. Short-, intermediate-, and long-term risks are evaluated by comparing aggregate exposure to the LOC to ensure that the MOE called for by the product of all applicable UFs is not exceeded. 1. Acute risk. There were no effects observed in oral toxicity studies including developmental toxicity studies in rats and rabbits that could be attributable to a single dose (exposure). Therefore, mesotrione 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 exposure to mesotrione from food and water will utilize 52% of the cPAD for the population group (All Infants (<1 year old)). There are no residential uses for mesotrione that result in chronic residential exposure to mesotrione. 3. Short-term risk. Short-term aggregate exposure takes into account residential exposure plus chronic exposure to food and water (considered to be a background exposure level). Mesotrione is currently registered for use on golf course turf grass that could result in short-term residential exposure and the Agency has determined that it is appropriate to aggregate chronic food PO 00000 Frm 00055 Fmt 4700 Sfmt 4700 9225 and water and short-term exposures for mesotrione. Post-application inhalation exposure is not expected and was not included in the risk estimates. No incidental oral exposure expected to adults or youth from residues on treated golf course grass. A summary of the assumptions for post application dermal exposure to golfers from mesotrione use on turf grass use and the risk assessment can be found at http:// www.regulations.gov in document ‘‘Petition#: 6F7162. Mesotrione: Human Health Risk Assessment for Proposed Section 3 New Uses on Asparagus, Grasses Grown for Seed, Oats, Okra, Rhubarb, Sugarcane, Grain Sorghum, Sweet Sorghum and Turf (Golf Course and Sod Farms)’’ at page 27 in docket ID number EPA–HQ–OPP–2006–0030. EPA has concluded that food, water, and post application golf course turf exposures result in aggregate MOEs of 12,000 for Adults 20-49 years old and 12,000 for Youth 13-19 years old. Both do not exceed the Level of Concern MOE of 3,000 for mesotrione. 4. Intermediate-term risk. Intermediate-term aggregate exposure takes into account residential exposure plus chronic exposure to food and water (considered to be a background exposure level). Though residential exposure could occur application to golf course turf is not expected to result in residential post-application exposure of more than 30 days duration. Therefore, the Agency has determined that it is not appropriate to aggregate chronic food and water and intermediate-term exposures for mesotrione. 5. Aggregate cancer risk for U.S. population. Mesotrione is classified as a ‘‘not likely’’ to be carcinogenic in humans based on the results of a carcinogenicity study in mice and the combined chronic toxicity and carcinogenicity study in the rat. Therefore, mesotrione is not expected to pose a cancer risk to humans. 6. Determination of safety. Based on these risk assessments, EPA concludes that there is a reasonable certainty that no harm will result to the general population or to infants and children from aggregate exposure to mesotrione residues. IV. Other Considerations A. Analytical Enforcement Methodology Adequate enforcement methodology (high-pressure liquid chromatography fluorescence detector [HPLC/FLD]) is available to enforce the tolerance expression. The method may be requested from: Chief, Analytical Chemistry Branch, Environmental E:\FR\FM\20FER1.SGM 20FER1 9226 Federal Register / Vol. 73, No. 34 / Wednesday, February 20, 2008 / Rules and Regulations Science Center, 701 Mapes Rd., Ft. Meade, MD 20755–5350; telephone number: (410) 305–2905; e-mail address: residuemethods@epa.gov. B. International Residue Limits There are no CODEX, Canadian, or Mexican tolerances/Maximum Residue Levels for mesotrione residues for the proposed crops. sroberts on PROD1PC70 with RULES V. Conclusion Therefore, the tolerance is established for residues of mesotrione, 2-[4(methylsulfonyl)-2-nitrobenzoyl]-1,3cyclohexanedione, in or on asparagus at 0.01 ppm; grass, seed screenings at 0.10 ppm; grass, straw at 0.10 ppm; grass, forage at 0.01 ppm; grass, hay at 0.01 ppm; oat, grain at 0.01 ppm; oat, straw at 0.01 ppm; oat, forage at 0.01 ppm; oat, hay at 0.01 ppm; okra at 0.01 ppm; rhubarb at 0.01 ppm; sorghum, grain, forage at 0.01 ppm; sorghum, grain, grain at 0.01 ppm; sorghum, grain, stover at 0.01 ppm; sorghum, sweet at 0.01 ppm and sugarcane, cane at 0.01 ppm. VI. Statutory and Executive Order Reviews This final rule establishes a tolerance under section 408(d) of FFDCA in response to a petition submitted to the Agency. The Office of Management and Budget (OMB) has exempted these types of actions from review under Executive Order 12866, entitled Regulatory Planning and Review (58 FR 51735, October 4, 1993). Because this rule has been exempted from review under Executive Order 12866, this rule is not subject to Executive Order 13211, Actions Concerning Regulations That Significantly Affect Energy Supply, Distribution, or Use (66 FR 28355, May 22, 2001) or Executive Order 13045, entitled Protection of Children from Environmental Health Risks and Safety Risks (62 FR 19885, April 23, 1997). This final rule does not contain any information collections subject to OMB approval under the Paperwork Reduction Act (PRA), 44 U.S.C. 3501 et seq., nor does it require any special considerations under Executive Order 12898, entitled Federal Actions to Address Environmental Justice in Minority Populations and Low-Income Populations (59 FR 7629, February 16, 1994). Since tolerances and exemptions that are established on the basis of a petition under section 408(d) of FFDCA, such as the tolerance in this final rule, do not require the issuance of a proposed rule, the requirements of the Regulatory Flexibility Act (RFA) (5 U.S.C. 601 et seq.) do not apply. VerDate Aug<31>2005 15:54 Feb 19, 2008 Jkt 214001 This final rule directly regulates growers, food processors, food handlers, and food retailers, not States or tribes, nor does this action alter the relationships or distribution of power and responsibilities established by Congress in the preemption provisions of section 408(n)(4) of FFDCA. As such, the Agency has determined that this action will not have a substantial direct effect on States or tribal governments, on the relationship between the national government and the States or tribal governments, or on the distribution of power and responsibilities among the various levels of government or between the Federal Government and Indian tribes. Thus, the Agency has determined that Executive Order 13132, entitled Federalism (64 FR 43255, August 10, 1999) and Executive Order 13175, entitled Consultation and Coordination with Indian Tribal Governments (65 FR 67249, November 6, 2000) do not apply to this rule. In addition, This rule does not impose any enforceable duty or contain any unfunded mandate as described under Title II of the Unfunded Mandates Reform Act of 1995 (UMRA) (Public Law 104–4). This action does not involve any technical standards that would require Agency consideration of voluntary consensus standards pursuant to section 12(d) of the National Technology Transfer and Advancement Act of 1995 (NTTAA), Public Law 104–113, section 12(d) (15 U.S.C. 272 note). Dated: February 7, 2008. Lois Rossi, Director, Registration Division, Office of Pesticide Programs. Therefore, 40 CFR chapter I is amended as follows: I PART 180—[AMENDED] 1. The authority citation for part 180 continues to read as follows: I Authority: 21 U.S.C. 321(q), 346a and 371. 2. Section 180.571 is amended by alphabetically adding the following commodities in the table in paragraph (a) to read as follows: I § 180.571 Mesotrione; tolerances for residues. * * * * * Parts per million Commodity Asparagus ......................... * * * Grass, seed screenings .... 0.01 * * 0.10 Grass, straw ..................... 0.10 Grass, forage .................... 0.01 Grass, hay ........................ 0.01 * * * Oat, grain .......................... * * 0.01 Oat, straw ......................... 0.01 Oat, forage ........................ 0.01 Oat, hay ............................ 0.01 VII. Congressional Review Act Okra .................................. 0.01 The Congressional Review Act, 5 U.S.C. 801 et seq., generally provides that before a rule may take effect, the agency promulgating the rule must submit a rule report to each House of the Congress and to the Comptroller General of the United States. EPA will submit a report containing this rule and other required information to the U.S. Senate, the U.S. House of Representatives, and the Comptroller General of the United States prior to publication of this final rule in the Federal Register. This final rule is not a ‘‘major rule’’ as defined by 5 U.S.C. 804(2). Rhubarb ............................ 0.01 Sorghum, grain, forage ..... 0.01 Sorghum, grain, grain ....... 0.01 Sorghum, grain, stover ..... 0.01 Sorghum, sweet ................ 0.01 Sugarcane, cane .............. 0.01 List of Subjects in 40 CFR Part 180 Environmental protection, Administrative practice and procedure, Agricultural commodities, Pesticides and pests, Reporting and recordkeeping requirements. PO 00000 * * * Fmt 4700 Sfmt 4700 * BILLING CODE 6560–50–S ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 180 [EPA–HQ–OPP–2006–0916; FRL–8343–6] Formetanate Hydrochloride; Pesticide Tolerances for Emergency Exemptions Environmental Protection Agency (EPA). AGENCY: Frm 00056 * [FR Doc. E8–3123 Filed 2–19–08; 8:45 am] E:\FR\FM\20FER1.SGM 20FER1

Agencies

[Federal Register Volume 73, Number 34 (Wednesday, February 20, 2008)]
[Rules and Regulations]
[Pages 9222-9226]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E8-3123]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[EPA-HQ-OPP-2007-0030; FRL-8349-7]


Mesotrione; Pesticide Tolerance

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This regulation establishes tolerances for residues of 
mesotrione in or on asparagus, grass grown for seed, oats, okra, 
rhubarb, grain sorghum, sweet sorghum, and sugarcane. Syngenta Crop 
Protection requested this tolerance under the Federal Food, Drug, and 
Cosmetic Act (FFDCA).

DATES: This regulation is effective February 20, 2008. Objections and 
requests for hearings must be received on or before April 21, 2008, 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-2007-0030. To access the 
electronic docket, go to http://www.regulations.gov, select ``Advanced 
Search,'' then ``Docket Search.'' Insert the docket ID number where 
indicated and select the ``Submit'' button. Follow the instructions on 
the regulations.gov website to view the docket index or access 
available documents. All documents in the docket are listed in the 
docket index available in 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: Erik Kraft, Registration Division 
(7505P), Office of Pesticide Programs, Environmental Protection Agency, 
1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone 
number: (703) 308-9358; e-mail address: kraft.erik @epa.gov.

SUPPLEMENTARY INFORMATION:

I. General Information

A. 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), e.g., agricultural 
workers; greenhouse, nursery, and floriculture workers; farmers.
     Animal production (NAICS code 112), e.g., cattle ranchers 
and farmers, dairy cattle farmers, livestock farmers.
     Food manufacturing (NAICS code 311), e.g., agricultural 
workers; farmers; greenhouse, nursery, and floriculture workers; 
ranchers; pesticide applicators.
     Pesticide manufacturing (NAICS code 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 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.

B. 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 EPA's tolerance regulations at 
40 CFR part 180 through the Government Printing Office's pilot e-CFR 
site at http://www.gpoaccess.gov/ecfr.

C. Can I File an Objection or Hearing Request?

    Under section 408(g) of FFDCA, 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-2007-0030 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 as required by 40 CFR part 178 on or 
before April 21, 2008.
    In addition to filing an objection or hearing request with the 
Hearing Clerk as described in 40 CFR part 178, please submit a copy of 
the filing that does not contain any CBI for inclusion in the public 
docket that is described in ADDRESSES. Information not marked 
confidential pursuant to 40 CFR part 2 may be disclosed publicly by EPA 
without prior notice. Submit this copy, identified by docket ID number 
EPA-HQ-OPP-2007-0030, 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'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 Facility telephone number is (703) 305-5805.

[[Page 9223]]

II. Petition for Tolerance

    In the Federal Register of April 25, 2006 (71 FR 24695) (FRL-8063-
7), EPA issued a notice pursuant to section 408(d)(3) of FFDCA, 21 
U.S.C. 346a(d)(3), announcing the filing of a pesticide petition (PP 
6F7023) by Syngenta Crop Protection, P.O. Box 18300, Greensboro, NC. 
The petition requested that 40 CFR 180.571 be amended by establishing 
tolerances for residues of the herbicide mesotrione, 2-[4- 
(methylsulfonyl)-2-nitrobenzoyl]-1,3-cyclohexanedione, in or on 
commodity asparagus at 0.01 parts per million (ppm); grass, seed 
screenings at 0.10 ppm; grass, straw at 0.10 ppm; grass, forage at 0.01 
ppm; grass, hay at 0.01 ppm; oats, grain, oats, straw at 0.01 ppm; 
oats, forage at 0.1 ppm; oats, hay at 0.01 ppm; okra at 0.01 ppm; 
rhubarb at 0.01 ppm; sorghum, forage at 0.01 ppm; sorghum, stover at 
0.01 ppm; sorghum, grain at 0.01 ppm; sorghum, sweet at 0.01 ppm; and 
sugarcane at 0.01 ppm. That notice referenced a summary of the petition 
prepared by Syngenta Crop Protection, the registrant, which is 
available to the public in the docket, http://www.regulations.gov. 
There were no comments received in response to the notice of filing.
    Based upon review of the data supporting the petition, to harmonize 
with the Food and Feed Commodity Vocabulary http://www.epa.gov/
opphed01/foodfeed/index.htm. EPA has amended the commodity listing to 
read: Asparagus at 0.01 ppm; grass, seed screenings at 0.10 ppm; grass, 
straw at 0.10 ppm; grass, forage at 0.01 ppm; grass, hay at 0.01 ppm; 
oat, grain at 0.01 ppm; oat, straw at 0.01 ppm; oat, forage at 0.01 
ppm; oat, hay at 0.01 ppm; okra at 0.01 ppm; rhubarb at 0.01 ppm; 
sorghum, grain, forage at 0.01 ppm; sorghum, grain, grain at 0.01 ppm; 
sorghum, grain, stover at 0.01 ppm; sorghum, sweet at 0.01 ppm and 
sugarcane, cane at 0.01 ppm.

III. 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.'' 
These provisions were added to FFDCA by the Food Quality Protection Act 
(FQPA) of 1996.
    Consistent with FFDCA section 408(b)(2)(D), and the factors 
specified in FFDCA section 408(b)(2)(D), 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 the petitioned-for tolerance 
for residues of mesotrione on asparagus at 0.01 ppm; grass, seed 
screenings at 0.10 ppm; grass, straw at 0.10 ppm; grass, forage at 0.01 
ppm; grass, hay at 0.01 ppm; oat, grain at 0.01 ppm; oat, straw at 0.01 
ppm; oat, forage at 0.01 ppm; oat, hay at 0.01 ppm; okra at 0.01 ppm; 
rhubarb at 0.01 ppm; sorghum, grain, forage at 0.01 ppm; sorghum, 
grain, grain at 0.01 ppm; sorghum, grain, stover at 0.01 ppm; sorghum, 
sweet at 0.01 ppm and sugarcane, cane at 0.01 ppm. EPA's assessment of 
exposures and risks associated with establishing the tolerance follows.

A. 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. Mesotrione has low acute toxicity via the oral, dermal, and 
inhalation routes. It is a mild eye irritant, but is not a dermal 
irritant or a dermal sensitizer. In subchronic and chronic oral 
studies, ocular lesions, liver and kidney effects, and/or body weight 
decrements were the major adverse effects seen in the rat, mouse, and 
dog. Plasma tyrosine levels were increased in the rat, mouse and dog in 
the chronic and reproduction studies in which levels were measured. The 
ocular, liver and kidney effects are believed to be mediated by the 
high tyrosine levels in the blood caused by inhibition of the enzyme 
HPPD. Even though the rat is the most sensitive species to this effect 
compared to the dog and the mouse, EPA concluded that the mouse is a 
more appropriate model for assessing human risk than is the rat. There 
was no evidence of carcinogenic potential in either the rat chronic 
toxicity/carcinogenicity or mouse carcinogenicity studies and no 
concern for mutagenicity. No evidence of neurotoxicity or 
neuropathology was seen in the acute and subchronic neurotoxicity 
studies. In the multi-generation mouse reproduction study, one first 
generation male and one first generation female had retinal detachment 
with marked cataractous changes at the highest dose tested (>1000 
milligrams/kilograms/day (mg/kg/day). In the subchronic toxicity dog 
study, the high-dose females had decreased absolute and relative brain 
weights; however, no microscopic abnormalities were noted in any brain 
tissues from the high-dose group and effect was not observed in the 
chronic toxicity dog study. Therefore, there is some concern about the 
effects of elevated plasma tyrosine levels on the developing nervous 
system in children due to a report that some patients with tyrosinemia 
III (an autosomal recessive disorder in which HPPD is deficient) were 
presented with mental retardation or neurological symptoms. There was 
evidence of increased susceptibility of rats, mice and rabbits to in 
utero and/or post-natal exposure to mesotrione. Specific information on 
the studies received and the nature of the adverse effects caused by 
mesotrione 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. The referenced 
document is available in the docket established by this action, which 
is described under ADDRESSES, and is identified as ``Petition: 
6F7162. Mesotrione: Human Health Risk Assessment for Proposed Section 3 
New Uses on Asparagus, Grasses Grown for Seed, Oats, Okra, Rhubarb, 
Sugarcane, Grain Sorghum, Sweet Sorghum and Turf (Golf Course and Sod 
Farms)'' in that docket. Additionally, mesotrione toxicological data 
are discussed in the final rule published in the Federal Register of 
June 21, 2001 (66 FR 33187) (FRL-6787-7).

B. Toxicological Endpoints

    For hazards that have a threshold below which there is no 
appreciable risk, the toxicological level of concern (LOC) is derived 
from the highest dose at which no adverse effects are observed (the 
NOAEL) in the toxicology study identified as appropriate for use in 
risk assessment. However, if a NOAEL cannot be determined, the lowest 
dose at which adverse effects of concern are

[[Page 9224]]

identified (the LOAEL) is sometimes used for risk assessment. 
Uncertainty/safety factors (UFs) are used in conjunction with the LOC 
to take into account 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. Safety 
is assessed for acute and chronic risks by comparing aggregate exposure 
to the pesticide to the acute population adjusted dose (aPAD) and 
chronic population adjusted dose (cPAD). The aPAD and cPAD are 
calculated by dividing the LOC by all applicable UFs. Short-, 
intermediate-, and long-term risks are evaluated by comparing aggregate 
exposure to the LOC to ensure that the margin of exposure (MOE) called 
for by the product of all applicable UFs is not exceeded.
    For non-threshold risks, the Agency assumes that any amount of 
exposure will lead to some degree of risk and estimates risk in terms 
of the probability of occurrence of additional adverse cases. 
Generally, cancer risks are considered non-threshold. 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/fedrgstr/EPA-PEST/1997/November/Day-26/p30948.htm.
    A summary of the toxicological endpoints for mesotrione used for 
human risk assessment can be found at http://www.regulations.gov in 
document ``Petition: 6F7162. Mesotrione: Human Health Risk 
Assessment for Proposed Section 3 New Uses on Asparagus, Grasses Grown 
for Seed, Oats, Okra, Rhubarb, Sugarcane, Grain Sorghum, Sweet Sorghum 
and Turf (Golf Course and Sod Farms)'' at page 15 in docket ID number 
EPA-HQ-OPP-2007-0030.

C. Exposure Assessment

    1. Dietary exposure from food and feed uses. In evaluating dietary 
exposure to mesotrione, EPA considered exposure under the petitioned-
for tolerances as well as all existing mesotrione tolerances in (40 CFR 
180.571). EPA assessed dietary exposures from mesotrione 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 
mesotrione; 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 Nationwide Continuing Surveys of Food Intake by Individuals 
(CSFII). As to residue levels in food, EPA assumed that all foods were 
treated for which there are proposed and established tolerances and 
that all the foods contain tolerance-level residues.
    iii. Cancer. Mesotrione was negative for carcinogenicity in feeding 
studies in rats and mice and was classified as ``not likely'' to be a 
human carcinogen. Therefore, a quantitative exposure assessment to 
evaluate cancer risk is unnecessary.
    2. Dietary exposure from drinking water.The Agency lacks sufficient 
monitoring data to complete a comprehensive dietary exposure analysis 
and risk assessment for mesotrione 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 environmental fate characteristics of 
mesotrione. 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 First Index Reservoir Screening Tool (FIRST) and 
Screening Concentration in Ground Water (SCI-GROW) models for turf 
grass (Golf Courses and Sod Farms), the estimated drinking water 
concentrations (EDWCs) of mesotrione for chronic exposures are 
estimated to be 4.7 parts per billion (ppb) for surface water and 0.18 
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 4.7 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).
    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 substances 
that have a common mechanism of toxicity.''
    Mesotrione, pyrasulfotole, isoxaflutole and topramezone belong to a 
class of herbicides that inhibit the liver enzyme 4-
hydroxyphenylpyruvate dioxygenase (HPPD), which is involved in the 
catabolism (metabolic breakdown) of tyrosine (an amino acid derived 
from proteins in the diet). Inhibition of HPPD can result in elevated 
tyrosine levels in the blood, a condition called tyrosinemia. HPPD-
inhibiting herbicides have been found to cause a number of toxicities 
in laboratory animal studies including ocular, developmental, liver and 
kidney effects. Of these toxicities, it is the ocular effect (corneal 
opacity) that is highly correlated with the elevated blood tyrosine 
levels. In fact, rats dosed with tyrosine alone show ocular opacities 
similar to those seen with HPPD inhibitors. Although the other 
toxicities may be associated with chemically-induced tyrosinemia, other 
mechanisms may also be involved.
    There are marked differences among species in the ocular toxicity 
associated with inhibition of HPPD. Ocular effects following treatment 
with HPPD inhibitor herbicides are seen in the rat but not in the 
mouse. Monkeys also seem to be recalcitrant to the ocular toxicity 
induced by HPPD inhibition. One explanation of this species-specific 
response in ocular opacity may be related to the species differences in 
the clearance of tyrosine. A metabolic pathway exists to remove 
tyrosine from the blood that involves a liver enzyme called tyrosine 
aminotransferase (TAT). In contrast to rats where ocular toxicity is 
observed following exposure to HPPD-inhibiting herbicides, mice and 
humans are unlikely to achieve the levels of plasma tyrosine necessary 
to produce ocular opacities because the activity of TAT in these 
species is much greater compared to rats. HPPD inhibitors (e.g., 
nitisinone) are used as an effective therapeutic agent to treat 
patients suffering from rare genetic diseases of tyrosine catabolism. 
Treatment starts in childhood but is often sustained throughout 
patient's lifetime. The human experience indicates that a therapeutic 
dose (1 mg/kg/day dose) of nitisinone has an excellent safety record in 
infants, children and adults and that serious adverse health outcomes 
have not been observed in a population followed for approximately a 
decade. Rarely, ocular effects are seen in patients with high plasma 
tyrosine levels; however, these effects are transient and can be 
readily reversed upon adherence to a restricted

[[Page 9225]]

protein diet. This indicates that an HPPD inhibitor in and of itself 
cannot easily overwhelm the tyrosine-clearance mechanism in humans.
    Therefore, exposure to environmental residues of HPPD-inhibiting 
herbicides are unlikely to result in the high blood levels of tyrosine 
and ocular toxicity in humans due to an efficient metabolic process to 
handle excess tyrosine. The Agency continues to study the complex 
relationships between elevated tyrosine levels and biological effects 
in various species. Nonetheless, as a worst case scenario, EPA has 
assessed aggregate exposure to mesotrione based on ocular effects in 
rats. For similar reasons, a semi-quantitative screening cumulative 
assessment was conducted using the rat ocular effects and 100% crop 
treated information. The results of this screening analysis did not 
indicate a concern. In the future, assessments of HPPD-inhibiting 
herbicides will consider more appropriate models and cross species 
extrapolation methods. Therefore, EPA has not conducted cumulative risk 
assessment with other HPPD inhibitors. 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 website at http://www.epa.gov/pesticides/cumulative.

D. Safety Factor for Infants and Children

    1.In general. Section 408 of FFDCA provides that EPA shall apply an 
additional (``10X'') 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 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. 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 FQPA 
safety factor value based on the use of traditional UFs and/or special 
FQPA safety factors, as appropriate.
    2. Pre-natal and post-natal sensitivity. There is quantitative 
evidence of increased susceptibility of the young in the oral prenatal 
developmental toxicity studies in rats, mice, and rabbits and in the 
multi-generation reproduction study in mice and lack of a developmental 
neurotoxicity study in mice. Quantitative evidence of increased 
susceptibility was not demonstrated in the multi-generation 
reproduction study in rats. However, no NOAEL was established for 
parental or offspring systemic toxicity. There is evidence of a 
qualitative increase in susceptibility since the tyrosinemia observed 
in the young was much more severe than that observed in the adults.
    3. Conclusion. There are two deficiencies in the mesotrione 
toxicity database. First, a Developmental Neurotoxicity Study has been 
required to assess the effects on the developing nervous/ocular system 
from exposed to mesotrione. Second, the mouse two-generation 
reproduction study, on which the Reference Dose/ Population Adjusted 
Dose [RfD/PAD] is based failed to identify a NOAEL. In light of this 
data gap, the necessity of a reliance on a LOAEL to calculate the RfD/
PAD, and the quantitative and qualitative evidence of increased 
susceptibility of the young discussed above, EPA is raising the 10X 
FQPA safety factor to the value of 30X.

E. Aggregate Risks and Determination of Safety

    Safety is assessed for acute and chronic risks by comparing 
aggregate exposure to the pesticide to the aPAD and cPAD. The aPAD and 
cPAD are calculated by dividing the LOC by all applicable UFs. For 
linear cancer risks, EPA calculates the probability of additional 
cancer cases given aggregate exposure. Short-, intermediate-, and long-
term risks are evaluated by comparing aggregate exposure to the LOC to 
ensure that the MOE called for by the product of all applicable UFs is 
not exceeded.
    1. Acute risk. There were no effects observed in oral toxicity 
studies including developmental toxicity studies in rats and rabbits 
that could be attributable to a single dose (exposure). Therefore, 
mesotrione 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 exposure to 
mesotrione from food and water will utilize 52% of the cPAD for the 
population group (All Infants (<1 year old)). There are no residential 
uses for mesotrione that result in chronic residential exposure to 
mesotrione.
    3. Short-term risk. Short-term aggregate exposure takes into 
account residential exposure plus chronic exposure to food and water 
(considered to be a background exposure level). Mesotrione is currently 
registered for use on golf course turf grass that could result in 
short-term residential exposure and the Agency has determined that it 
is appropriate to aggregate chronic food and water and short-term 
exposures for mesotrione. Post-application inhalation exposure is not 
expected and was not included in the risk estimates. No incidental oral 
exposure expected to adults or youth from residues on treated golf 
course grass. A summary of the assumptions for post application dermal 
exposure to golfers from mesotrione use on turf grass use and the risk 
assessment can be found at http://www.regulations.gov in document 
``Petition: 6F7162. Mesotrione: Human Health Risk Assessment 
for Proposed Section 3 New Uses on Asparagus, Grasses Grown for Seed, 
Oats, Okra, Rhubarb, Sugarcane, Grain Sorghum, Sweet Sorghum and Turf 
(Golf Course and Sod Farms)'' at page 27 in docket ID number EPA-HQ-
OPP-2006-0030.
    EPA has concluded that food, water, and post application golf 
course turf exposures result in aggregate MOEs of 12,000 for Adults 20-
49 years old and 12,000 for Youth 13-19 years old. Both do not exceed 
the Level of Concern MOE of 3,000 for mesotrione.
    4. Intermediate-term risk. Intermediate-term aggregate exposure 
takes into account residential exposure plus chronic exposure to food 
and water (considered to be a background exposure level).
    Though residential exposure could occur application to golf course 
turf is not expected to result in residential post-application exposure 
of more than 30 days duration. Therefore, the Agency has determined 
that it is not appropriate to aggregate chronic food and water and 
intermediate-term exposures for mesotrione.
    5. Aggregate cancer risk for U.S. population. Mesotrione is 
classified as a ``not likely'' to be carcinogenic in humans based on 
the results of a carcinogenicity study in mice and the combined chronic 
toxicity and carcinogenicity study in the rat. Therefore, mesotrione is 
not expected to pose a cancer risk to humans.
    6. Determination of safety. Based on these risk assessments, EPA 
concludes that there is a reasonable certainty that no harm will result 
to the general population or to infants and children from aggregate 
exposure to mesotrione residues.

IV. Other Considerations

A. Analytical Enforcement Methodology

    Adequate enforcement methodology (high-pressure liquid 
chromatography fluorescence detector [HPLC/FLD]) is available to 
enforce the tolerance expression. The method may be requested from: 
Chief, Analytical Chemistry Branch, Environmental

[[Page 9226]]

Science Center, 701 Mapes Rd., Ft. Meade, MD 20755-5350; telephone 
number: (410) 305-2905; e-mail address: residuemethods@epa.gov.

B. International Residue Limits

    There are no CODEX, Canadian, or Mexican tolerances/Maximum Residue 
Levels for mesotrione residues for the proposed crops.

V. Conclusion

    Therefore, the tolerance is established for residues of mesotrione, 
2-[4- (methylsulfonyl)-2-nitrobenzoyl]-1,3-cyclohexanedione, in or on 
asparagus at 0.01 ppm; grass, seed screenings at 0.10 ppm; grass, straw 
at 0.10 ppm; grass, forage at 0.01 ppm; grass, hay at 0.01 ppm; oat, 
grain at 0.01 ppm; oat, straw at 0.01 ppm; oat, forage at 0.01 ppm; 
oat, hay at 0.01 ppm; okra at 0.01 ppm; rhubarb at 0.01 ppm; sorghum, 
grain, forage at 0.01 ppm; sorghum, grain, grain at 0.01 ppm; sorghum, 
grain, stover at 0.01 ppm; sorghum, sweet at 0.01 ppm and sugarcane, 
cane at 0.01 ppm.

VI. Statutory and Executive Order Reviews

    This final rule establishes a tolerance under section 408(d) of 
FFDCA in response to a petition submitted to the Agency. The Office of 
Management and Budget (OMB) has exempted these types of actions from 
review under Executive Order 12866, entitled Regulatory Planning and 
Review (58 FR 51735, October 4, 1993). Because this rule has been 
exempted from review under Executive Order 12866, this rule is not 
subject to Executive Order 13211, Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use (66 FR 28355, 
May 22, 2001) or Executive Order 13045, entitled Protection of Children 
from Environmental Health Risks and Safety Risks (62 FR 19885, April 
23, 1997). This final rule does not contain any information collections 
subject to OMB approval under the Paperwork Reduction Act (PRA), 44 
U.S.C. 3501 et seq., nor does it require any special considerations 
under Executive Order 12898, entitled Federal Actions to Address 
Environmental Justice in Minority Populations and Low-Income 
Populations (59 FR 7629, February 16, 1994).
    Since tolerances and exemptions that are established on the basis 
of a petition under section 408(d) of FFDCA, such as the tolerance in 
this final rule, do not require the issuance of a proposed rule, the 
requirements of the Regulatory Flexibility Act (RFA) (5 U.S.C. 601 et 
seq.) do not apply.
    This final rule directly regulates growers, food processors, food 
handlers, and food retailers, not States or tribes, nor does this 
action alter the relationships or distribution of power and 
responsibilities established by Congress in the preemption provisions 
of section 408(n)(4) of FFDCA. As such, the Agency has determined that 
this action will not have a substantial direct effect on States or 
tribal governments, on the relationship between the national government 
and the States or tribal governments, or on the distribution of power 
and responsibilities among the various levels of government or between 
the Federal Government and Indian tribes. Thus, the Agency has 
determined that Executive Order 13132, entitled Federalism (64 FR 
43255, August 10, 1999) and Executive Order 13175, entitled 
Consultation and Coordination with Indian Tribal Governments (65 FR 
67249, November 6, 2000) do not apply to this rule. In addition, This 
rule does not impose any enforceable duty or contain any unfunded 
mandate as described under Title II of the Unfunded Mandates Reform Act 
of 1995 (UMRA) (Public Law 104-4).
    This action does not involve any technical standards that would 
require Agency consideration of voluntary consensus standards pursuant 
to section 12(d) of the National Technology Transfer and Advancement 
Act of 1995 (NTTAA), Public Law 104-113, section 12(d) (15 U.S.C. 272 
note).

VII. Congressional Review Act

    The Congressional Review Act, 5 U.S.C. 801 et seq., generally 
provides that before a rule may take effect, the agency promulgating 
the rule must submit a rule report to each House of the Congress and to 
the Comptroller General of the United States. EPA will submit a report 
containing this rule and other required information to the U.S. Senate, 
the U.S. House of Representatives, and the Comptroller General of the 
United States prior to publication of this final rule in the Federal 
Register. This final rule is not a ``major rule'' as defined by 5 
U.S.C. 804(2).

List of Subjects in 40 CFR Part 180

    Environmental protection, Administrative practice and procedure, 
Agricultural commodities, Pesticides and pests, Reporting and 
recordkeeping requirements.


    Dated: February 7, 2008.
Lois Rossi,
Director, Registration Division, Office of Pesticide Programs.

0
Therefore, 40 CFR chapter I is amended as follows:

PART 180--[AMENDED]

0
1. The authority citation for part 180 continues to read as follows:

    Authority: 21 U.S.C. 321(q), 346a and 371.

0
2. Section 180.571 is amended by alphabetically adding the following 
commodities in the table in paragraph (a) to read as follows:


Sec.  180.571  Mesotrione; tolerances for residues.

* * * * *

------------------------------------------------------------------------
                                                             Parts per
                        Commodity                             million
------------------------------------------------------------------------
Asparagus...............................................            0.01
------------------------------------------------------------------------
                                * * * * *
Grass, seed screenings..................................            0.10
------------------------------------------------------------------------
Grass, straw............................................            0.10
------------------------------------------------------------------------
Grass, forage...........................................            0.01
------------------------------------------------------------------------
Grass, hay..............................................            0.01
------------------------------------------------------------------------
                                * * * * *
Oat, grain..............................................            0.01
------------------------------------------------------------------------
Oat, straw..............................................            0.01
------------------------------------------------------------------------
Oat, forage.............................................            0.01
------------------------------------------------------------------------
Oat, hay................................................            0.01
------------------------------------------------------------------------
Okra....................................................            0.01
------------------------------------------------------------------------
Rhubarb.................................................            0.01
------------------------------------------------------------------------
Sorghum, grain, forage..................................            0.01
------------------------------------------------------------------------
Sorghum, grain, grain...................................            0.01
------------------------------------------------------------------------
Sorghum, grain, stover..................................            0.01
------------------------------------------------------------------------
Sorghum, sweet..........................................            0.01
------------------------------------------------------------------------
Sugarcane, cane.........................................            0.01
------------------------------------------------------------------------

* * * * *
[FR Doc. E8-3123 Filed 2-19-08; 8:45 am]
BILLING CODE 6560-50-S