Daily Rules, Proposed Rules, and Notices of the Federal Government
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 code 111).
• Animal production (NAICS code 112).
• Food manufacturing (NAICS code 311).
• Pesticide manufacturing (NAICS code 32532).
This listing is not intended to be exhaustive, but rather 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
In addition to accessing electronically available documents at
Under section 408(g) of FFDCA, 21 U.S.C. 346a, any person may file an objection to any aspect of this regulation and may also request a hearing on those objections. 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-2007-0672 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 February 9, 2009.
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
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
Consistent with section 408(b)(2)(D) of FFDCA, and the factors specified in section 408(b)(2)(D) of FFDCA, EPA has reviewed the available scientific data and other relevant information in support of this action. EPA has sufficient data to assess the hazards of and to make a determination on aggregate exposure for the petitioned-for tolerances for residues of the herbicide safener, mefenpyr-diethyl, in or on soybean seed at 0.02 ppm, soybean forage at 0.1 ppm, soybean hay at 0.1 ppm, and canola seed at 0.02 ppm; as well as the petitioned-for request to increase the maxium allowable seasonal use rate from 0.026 lb safener/A to 0.053 lb safener/A. EPA's assessment of exposures and risks associated with establishing tolerances follows.
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.
Mefenpyr-diethyl has low acute toxicity by the oral, dermal, and inhalation routes of exposure. It is not a dermal irritant but is a slight dermal sensitizer and ocular irritant. Metabolism studies indicate that mefenpyr-diethyl is rapidly metabolized, widely distributed, and primarily excreted via the urine. Repeat exposure via the dermal route did not induce any treatment-related effects at dose levels up to and including the limit dose. Repeated exposure studies via the oral route demonstrated that the target organs are the liver and hematopoietic system in dogs, mice, and rats. Mefenpyr-diethyl was negative for carcinogenicity in rats and mice, and classified as “not likely to be carcinogenic to humans.” Mefenpyr-diethyl did not show any genotoxic potential. Developmental toxicity was not observed in the rat at the limit dose (1,000 milligrams/kilogram/day (mg/kg/day)) but was observed in the rabbit (abortions) at the same dose level producing maternal toxicity. Mefenpyr-diethyl did not induce any signs of reproductive toxicity or neurotoxic potential. The developmental toxicity studies in rats and rabbits, as well as the reproductive toxicity study in rats, did not demonstrate any prenatal or postnatal sensitivity. There is a lack of evidence of neurotoxicity in any study on mefenpyr-diethyl and therefore there is no concern for neurotoxicity resulting from exposure to mefenpyr-diethyl.
For hazards that have a threshold below which there is no appreciable risk, a toxicological point of departure (POD) is identified as the basis for derivation of reference values for risk assessment. The POD may be defined as 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 identified (the LOAEL) or a Benchmark Dose (BMD) approach is sometimes used for risk assessment. Uncertainty/safety factors (UFs) are used in conjunction with the POD 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 dietary risks by comparing aggregate food and water 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 POD by all applicable UFs. Aggregate short-, intermediate-, and chronic-term risks are evaluated by comparing food, water, and residential exposure to the POD to ensure that the margin of exposure (MOE) called for by the product of all applicable UFs is not exceeded. This latter value is referred to as the Level of Concern (LOC).
For non-threshold risks, the Agency assumes that any amount of exposure will lead to some degree of risk. Thus, the Agency estimates risk in terms of the probability of an occurrence of the adverse effect greater than that expected in a lifetime. For more information on the general principles EPA uses in risk characterization and a complete description of the risk assessment process, see
A summary of the toxicological endpoints for mefenpyr-diethyl for human risk assessment is shown in Table 1 of this unit.
No new magnitude of the residue data, reflecting the new proposed seasonal rate of 0.053 lb safener/A, were submitted for the primary crop commodities. It is, however, noted that the field trial data that were previously submitted in support of the petition to establish tolerances for primary crops were conducted at an exaggerated rate of 0.089 lb/safener/A. Therefore, the Agency has determine that the established tolerances for primary crop commodities remain adequate to support the proposed higher application rate.
Based on the First Index Reservoir Screening Tool (FIRST) and Screening Concentration in Ground Water (SCI-GROW) models, the estimated drinking water concentrations (EDWCs) of mefenpyr-diethyl and its transformation products for chronic exposures for non-cancer assessments are estimated to be 3 parts per billion (ppb) for surface water and 4 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 ppb was used to assess the contribution to drinking water.
Developmental toxicity was not observed in the rat at the limit dose (1,000 mg/kg/day). The only effects observed in the rat developmental toxicity study were decreased body-weight gain and food efficiency during the first week of dosing and increased spleen weights in the maternal animal and a marginal decrease in fetal body weight/body-weight gain during lactation (postnatal study). In the rabbit developmental toxicity study, developmental toxicity (abortion) was observed at the same dose level producing maternal toxicity (250 mg/kg/day).
In the reproduction study, parental toxicity consisted of decreased body weight and body-weight gain, and an increase in spleen weight and in the severity (not incidence) of splenic extramedullary hematopoiesis in females. In the pups, decreased body weight and body-weight gains were observed at the same dose levels as the parental animals. The NOAEL is 82 mg/kg/day (1,000 ppm) for both the parental animal and offspring.
i. The toxicity database for mefenpyr-diethyl is complete, with the exception of immunotoxicity studies which are new data requirements under the revised Part 158 Toxicology Data Requirements (40 CFR part 158). In the absence of these studies, EPA has evaluated the available toxicity data for mefenpyr-diethyl and determined that an additional database uncertainty factor is not needed, based on the following conclusions:
No acute and subchronic Neurotoxcity studies are available, however there is no evidence of neurotoxicity in the toxicology database on mefenpyr-diethyl, which includes subchronic, chronic, developmental toxicity, and reproduction studies performed at dose of 250 mg/kg/day and above. Therefore, based on the above considerations, the Agency does not believe that conducting acute and subchronic neurotoxicity studies will result in a NOAEL less than the NOAEL of 51 mg/kg/day already set for mefenpyr-diethyl; therefore additional neurotoxicity studies are not necessary and the 10x safety factor can be reduced to 1x.
Considering that the application of mefenpyr-diethyl will be by either aerial application or spray boom equipment, the 28-day inhalation study is required as confirmatory data. However, the additional uncertainty factor for database uncertainties does not need to be applied since the MOE is 1,000 and significant inhalation exposures of concern are not anticipated.
EPA considered the entire toxicity database for mefenpyr-diethyl for potential adverse effects on the thymus and spleen as indications of potential immunotoxicity and noted enlarged spleens; more severe hematopoiesis and hemosiderin deposits and increased spleen weights were observed in mice at doses greater than the limit dose. However, these were determined to be non-specific changes not indicative of immunotoxicity. Therefore, based on the above considerations, EPA does not believe that conducting a special series (Harmonized Guideline 870.7800), immunotoxicity study will result in a NOAEL less than the NOAEL of 51 mg/kg/day already set for mefenpyr-diethyl and an additional uncertainty factor for database uncertainties does not need to be applied.
ii. There is no indication that mefenpyr-diethyl is a neurotoxic chemical and there is no need for a developmental neurotoxicity study or additional UFs to account for neurotoxicity.
iii. There is no evidence that mefenpyr-diethyl results in increased susceptibility in
iv. There are no residual uncertainties identified in the exposure databases. The dietary food exposure assessments were performed assuming 100 PCT and tolerance-level residues. EPA made conservative (protective) assumptions in the ground and surface water modeling used to assess exposure to mefenpyr-diethyl in drinking water. These assessments will not underestimate the exposure and risks posed by mefenpyr-diethyl.
EPA determines whether acute and chronic pesticide exposures are safe by comparing aggregate exposure estimates to the aPAD and cPAD. The aPAD and cPAD represent the highest safe exposures, taking into account all appropriate SFs. EPA calculates the aPAD and cPAD by dividing the POD by all applicable UFs. For linear cancer risks, EPA calculates the probability of additional cancer cases given the estimated aggregate exposure. Short-, intermediate-, and chronic-term risks are evaluated by comparing the estimated aggregate food, water, and residential exposure to the POD to ensure that the MOE called for by the product of all applicable UFs is not exceeded.
There are no residential uses for mefenpyr-diethyl, therefore the aggregate risk assessments include the contribution of risk from dietary (food and water) sources only.
An enforcement method for plants entitled “An Analytical Method for Determination of Residues of AE F107892 (mefenpyr-diethyl) and its Metabolites in Wheat and Barley by Gas Chromatography using Mass Selective Detection (Report Supplement to EPA MRID 45457401)” is available. Radiovalidation and independent laboratory validation (ILV) data have been submitted for the plant method. The Agency analytical lab has concluded that this method is suitable for food tolerance enforcement of mefenpyr-diethyl and its 2,4-dichlorophenyl-pyrazoline metabolites. The method may be requested from: Chief, Analytical Chemistry Branch, Environmental Science Center, 701 Mapes Rd., Ft. Meade, MD 20755-5350; telephone number: (410) 305-2905; e-mail address: firstname.lastname@example.org.
No Codex, Canadian, or Mexican maximum residue limits are established for residues of mefenpyr-diethyl and its metabolites in crop or livestock commodities; therefore, there are no issues with international harmonization raised by this action.
Therefore, 40 CFR 180.509 is amended for the herbicide safener, mefenpyr-diethyl, 1-(2,4-dichlorophenyl)-4,5-dihydro-5-methyl-1H-pyrazole-3,5-dicarboxylic acid, diethyl ester and its 2,4-dichlorophenyl-pyrazoline metabolites by increasing the maximum allowable seasonal use rate to 0.053 lb safener/A, as well as rotation crop tolerances are established for residues of the herbicide safener, mefenpyr-diethyl, 1-(2,4-dichlorophenyl)-4,5-dihydro-5-methyl-1H-pyrazole-3,5-dicarboxylic acid, diethyl ester and its 2,4-dichlorophenyl-pyrazoline metabolites in or on soybean seed at 0.02 ppm; soybean forage at 0.1 ppm; soybean hay at 0.1 ppm; and canola seed at 0.02 ppm.
It should be noted that no new magnitude of the residue data, reflecting the new proposed seasonal rate of 0.053 lb safener/A, were submitted for the primary crop commodities. However, field trail data that were previously submitted in support of the petition to establish tolerances for primary crops were conducted at an exaggerated rate of 0.089 lb safener/A. Therefore, the Agency determined that the established tolerances for primary crop commodities remain adequate to support the proposed higher application rate.
This final rule establishes tolerances 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
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
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
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).
The Congressional Review Act, 5 U.S.C. 801
Environmental protection, Administrative practice and procedure, Agricultural commodities, Pesticides and pests, Reporting and recordkeeping requirements.
21 U.S.C. 321(q), 346a and 371.