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Dimethenamid; Pesticide Tolerances for Emergency Exemptions

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Information about this document as published in the Federal Register.

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Start Preamble

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Final rule.

SUMMARY:

This regulation establishes time-limited tolerances for residues of Start Printed Page 51545dimethenamid, 2-chloro-N-[(1-methyl-2-methoxy)ethyl]-N- (2,4-dimethylthien-3-yl)-acetamide in or on dry bulb onions, sugar beets roots, tops, pulp and molasses. This action is in response to EPA's granting of an emergency exemption under section 18 of the Federal Insecticide, Fungicide, and Rodenticide Act authorizing use of the pesticide on dry bulb onions and sugar beets. This regulation establishes a maximum permissible level for residues of dimethenamid in these food commodities. The tolerances will expire and are revoked on December 31, 2002.

DATES:

This regulation is effective August 24, 2000. Objections and requests for hearings, identified by docket control number OPP-301038, must be received by EPA on or before October 23, 2000.

ADDRESSES:

Written objections and hearing requests may be submitted by mail, in person, or by courier. Please follow the detailed instructions for each method as provided in Unit VII. of the SUPPLEMENTARY INFORMATION. To ensure proper receipt by EPA, your objections and hearing requests must identify docket control number OPP-301038 in the subject line on the first page of your response.

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FOR FURTHER INFORMATION CONTACT:

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

End Further Info End Preamble Start Supplemental Information

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 categories and entities may include, but are not limited to:

CategoriesNAICSExamples of Potentially Affected Entities
Industry111Crop production
112Animal production
311Food manufacturing
32532Pesticide manufacturing

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 the table could also be affected. The North American Industrial Classification System (NAICS) codes have been provided to assist you and others in determining whether or not this action might apply to certain entities. If you have questions regarding the applicability of this action to a particular entity, consult the person listed under FOR FURTHER INFORMATION CONTACT.

B. How Can I Get Additional Information, Including Copies of This Document and Other Related Documents?

1. Electronically. You may obtain electronic copies of this document, and certain other related documents that might be available electronically, from the EPA Internet Home Page at http://www.epa.gov/​. To access this document, on the Home Page select “Laws and Regulations,” “Regulations and Proposed Rules,” and then look up the entry for this document under the “Federal Register—Environmental Documents.” You can also go directly to the Federal Register listings at http://www.epa.gov/​fedrgstr/​.

2. In person. The Agency has established an official record for this action under docket control number OPP-301038. The official record consists of the documents specifically referenced in this action, and other information related to this action, including any information claimed as Confidential Business Information (CBI). This official record includes the documents that are physically located in the docket, as well as the documents that are referenced in those documents. The public version of the official record does not include any information claimed as CBI. The public version of the official record, which includes printed, paper versions of any electronic comments submitted during an applicable comment period is available for inspection in the Public Information and Records Integrity Branch (PIRIB), Rm. 119, Crystal Mall #2, 1921 Jefferson Davis Hwy., Arlington, VA, from 8:30 a.m. to 4 p.m., Monday through Friday, excluding legal holidays. The PIRIB telephone number is (703) 305-5805.

II. Background and Statutory Findings

EPA, on its own initiative, in accordance with sections 408(e) and 408 (l)(6) of the Federal Food, Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 346a, is establishing tolerances for residues of the herbicide dimethenamid, 2-chloro-N-[(1-methyl-2-methoxy)ethyl]-N- (2,4-dimethylthien-3-yl)-acetamide, in or on dry bulb onions at 0.01 part per million (ppm), sugar beets roots and tops at 0.01 ppm and sugar beet dry pulp and molasses at 0.05 ppm. These tolerances will expire and are revoked on December 31, 2002. EPA will publish a document in the Federal Register to remove the revoked tolerances from the Code of Federal Regulations.

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

Section 408(b)(2)(A)(i) of the FFDCA allows EPA to establish a tolerance (the legal limit for a pesticide chemical residue in or on a food) only if EPA determines that the tolerance is “safe.” Section 408(b)(2)(A)(ii) 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) requires EPA to give special consideration to exposure of infants and children to the pesticide chemical residue in establishing a tolerance and to “ensure that there is a reasonable certainty that no harm will result to infants and children from aggregate exposure to the pesticide chemical residue. . . .”

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

III. Emergency Exemption for Dimethenamid on Onions and Sugar Beets and FFDCA Tolerances

1. Onions. Onions in New York are seeded in early spring in cool soils and, therefore, grow very slowly during the first weeks of the season, thus, onions can quickly be overrun by early germinating weeds. Because of the manner in which an onion plant grows, Start Printed Page 51546it never develops a leaf canopy that shades the soil as effectively as do most crops. Consequently, an onion crop remains subject to weed competition throughout the growing season. Any weeds not controlled during the first 6-8 weeks usually must be removed by hand, as they are no longer susceptible to most postemergence herbicides and cannot be removed by mechanical cultivation. For weeds within the onion row, even hand weeding becomes impractical as weeds get large because they cannot be pulled out of the soil without uprooting adjacent onion plants.

Until the mid 1980's, New York onion growers relied on the herbicide, Randox, for effective broad spectrum weed control. After Randox was discontinued, it was replaced primarily by Prowl. However, Prowl has no activity on yellow nutsedge and in the last 10 to 15 years almost all of muck soil onion fields have been infested with yellow nutsedge. Prowl also fails to control a number of other broad leaf weeds that Randox once controlled. Dual, a herbicide registered for use to control yellow nutsedge, only provides limited control because it can not be used until the onions are in the 2-leaf stage and in most cases yellow nutsedge infestations are out of control by that time.

2. Sugar Beets. Historically, one application of Ro-Neet applied alone or sequentially with one application of Eptam, followed by one or two cultivations provided acceptable season-long control of weeds for many Washington sugar beet growers. By 1998, growers began to question whether products that had once provided effective control in sugar beets were still providing acceptable levels of control. By the 1999 growing season, growers felt that currently registered herbicides were no longer sufficient to allow cost effective sugar beet production.

EPA has authorized under FIFRA section 18 the use of dimethenamid on dry bulb onions in New York and sugar beets in Washington for control of weeds. After having reviewed the submission, EPA concurs that emergency conditions exist for these States.

As part of its assessment of this emergency exemption, EPA assessed the potential risks presented by residues of dimethenamid in or on dry bulb onions and sugar beets. In doing so, EPA considered the safety standard in FFDCA section 408(b)(2), and EPA decided that the necessary tolerances under FFDCA section 408(l)(6) would be consistent with the safety standard and with FIFRA section 18. Consistent with the need to move quickly on the emergency exemption in order to address an urgent non-routine situation and to ensure that the resulting food is safe and lawful, EPA is issuing these tolerances without notice and opportunity for public comment as provided in section 408(l)(6). Although these tolerances will expire and are revoked on December 31, 2002, under FFDCA section 408(l)(5), residues of the pesticide not in excess of the amounts specified in the tolerance remaining in or on dry bulb onions and sugar beets after that date will not be unlawful, provided the pesticide is applied in a manner that was lawful under FIFRA, and the residues do not exceed a level that was authorized by these tolerances at the time of that application. EPA will take action to revoke these tolerances earlier if any experience with, scientific data on, or other relevant information on this pesticide indicate that the residues are not safe.

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

IV. Aggregate Risk Assessment and Determination of Safety

EPA performs a number of analyses to determine the risks from aggregate exposure to pesticide residues. For further discussion of the regulatory requirements of section 408 and a complete description of the risk assessment process, see the final rule on Bifenthrin Pesticide Tolerances (62 FR 62961, November 26, 1997) (FRL-5754-7).

Consistent with section 408(b)(2)(D), 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 dimethenamid and to make a determination on aggregate exposure, consistent with section 408(b)(2), for time-limited tolerances for residues of dimethenamid in or on dry bulb onions at 0.01 ppm, sugar beets roots and tops at 0.01 ppm and sugar beet dry pulp and molasses at 0.05 ppm. EPA's assessment of the dietary exposures and risks associated with establishing the tolerances follows.

A. Toxicological Endpoints

The dose at which no adverse effects are observed (NOAEL) from the toxicology study identified as appropriate for use in risk assessment is used to estimate the toxicological endpoint. However, the lowest dose at which adverse effects of concern are identified (LOAEL) is sometimes used for risk assessment if no NOAEL was achieved in the toxicology study selected. An uncertainty factor (UF) is applied to reflect uncertainties inherent in the extrapolation from laboratory animal data to humans and in the variations in sensitivity among members of the human population as well as other unknowns. An UF of 100 is routinely used, 10X to account for interspecies differences and 10x for intraspecies differences.

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

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

The linear default risk methodology (Q*) is the primary method currently used by the Agency to quantify carcinogenic risk. The Q* approach assumes that any amount of exposure will lead to some degree of cancer risk. A Q* is calculated and used to estimate risk which represents a probability of occurrence of additional cancer cases (e.g., risk is expressed as 1 × 10−6 or one in a million). Under certain specific Start Printed Page 51547circumstances, MOE calculations will be used for the carcinogenic risk assessment. In this non-linear approach, a “point of departure” is identified below which carcinogenic effects are not expected. The point of departure is typically a NOAEL based on an endpoint related to cancer effects though it may be a different value derived from the dose response curve. To estimate risk, a ratio of the point of departure to exposure (MOEcancer = point of departure/exposures) is calculated. The RfD approach is used when the chronic dietary risk assessment using the RfD will be adequately protective for cancer risk as well as other chronic effects. Therefore, with the RfD approach no separate carcinogenic risk assessment is necessary. The doses and toxicological endpoints selected and the LOC for margins of exposure for various exposures scenarios are summarized in the following Table 1:

Table 1.—Summary of Toxicological Dose and Endpoints for Dimethenamid for Use in Human Risk Assessment

Exposure scenarioDose used in risk assessment, UFFQPA SF* and level of concern for risk assessmentStudy and toxicological effects
Acute dietary females 13-50 years of ageNOAEL = 215 mg/kg/day; UF = 100; Acute RfD = 2.15 mg/kg/dayFQPA SF = 10x; aPAD = acute RfD ÷ FQPA SF = 0.215 mg/kg/dayDevelopmental toxicity, rat; LOAEL is 425 mg/kg/day based on early resorption.
Acute Dietary general population including infants and childrenNOAEL = 215 mg/kg/day; UF = 100; Acute RfD = 2.15 mg/kg/dayFQPA SF = 10x aPAD = acute RfD ÷ FQPA SF = 0.215 mg/kg/dayDevelopmental toxicity, rat; LOAEL is 425 mg/kg/day based on early resorption.
Chronic dietary all populationsNOAEL = 5.1 mg/kg/day; UF = 100; Chronic RfD = 0.05 mg/kg/dayFQPA SF = 10x; cPAD = chronic RfD ÷ FQPA SF = 0.005 mg/kg/dayChronic rat study; LOAEL is 36 mg/kg/day (males) based on increased incidences of non-neoplastic alterations in liver, parathyroid and stomach of males and ovary of females, as well as decreased food efficiency in females.
Short-Term dermal (1 to 7 days) (residential)NoneNoneNone
intermediate-Term dermal (1 week to several months) (residential)NoneNoneNone
long-Term dermal (several months to lifetime) (residential)NoneNoneNone
Short-Term Inhalation (1 to 7 days) (residential)NoneNoneNone
intermediate-Term Inhalation (1 week to several months) (residential)NoneNoneNone
long-Term Inhalation (several months to lifetime) (residential)NoneNoneNone
Cancer (oral, dermal, inhalation)NOAEL = 5.1 mg/kg/day; UF = 100; Chronic RfD = 0.05 mg/kg/dayCategory “C” (possible human carcinogen)Chronic rat study; increased tumor incidence only in rats (not mice). Significant increasing dose-related trend in combined benign and/or malignant liver tumor rates in males (not significant pair-wise comparison). In females, significantly increasing dose-related trend in ovarian adenomas (not significant pair-wise comparison). Incidence at 80 mg/kg/day (HDT) about twice the average of historical incidence. Quantitative cancer risk assessment not required.
* The reference to the FQPA Safety Factor refers to any additional safety factor retained due to concerns unique to the FQPA.

B. Exposure Assessment

1. Dietary exposure from food and feed uses. Dimethenamid is registered for use on various agricultural commodities. Tolerances have been established (40 CFR 180.464) for the residues of dimethenamid, in or on dry beans, corn, sweet corn, peanuts, sorghum and soybeans. Currently, dimethenamid is not registered on any use sites which would result in non-dietary, non-occupational exposure. Therefore, EPA expects only dietary and occupational exposure will result from the use of dimethenamid. Risk assessments were conducted by EPA to assess dietary exposures from dimethenamid in food as follows:

i. Acute exposure. Acute dietary risk assessments are performed for a food-Start Printed Page 51548use 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. The Dietary Exposure Evaluation Model (DEEM®) analysis evaluated the individual food consumption as reported by respondents in the USDA 1989-1992 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 acute exposure assessments: all residues occurred at tolerance levels and 100%% of crops with dimethenamid tolerances were treated.

ii. Chronic exposure. In conducting this chronic dietary risk assessment the DEEM® analysis evaluated the individual food consumption as reported by respondents in the USDA 1989-1992 nationwide CSFII and accumulated exposure to the chemical for each commodity. The following assumptions were made for the chronic exposure assessments: all residues occurred at tolerance levels and that 100%% of crops with dimethenamid tolerances were treated.

iii. Cancer. Dimethenamid has been classified as a Category “C” (possible human carcinogen), based on increased tumor incidence only in rats (not mice). The Agency determined that a quantitative cancer risk assessment is not required. The RfD approach was used to estimate cancer risk. Therefore the chronic (non-cancer) risk assessment is adequate estimate of cancer risk as well as other chronic effects.

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

The Agency uses the Generic Estimated Environmental Concentration (GENEEC) or the Pesticide Root Zone/Exposure Analysis Modeling System (PRZM/EXAMS) to estimate pesticide concentrations in surface water and SCI-GROW, which predicts pesticide concentrations in groundwater. In general, EPA will use GENEEC (a tier 1 model) before using PRZM/EXAMS (a tier 2 model) for a screening-level assessment for surface water. The GENEEC model is a subset of the PRZM/EXAMS model that uses a specific high-end runoff scenario for pesticides. GENEEC incorporates a farm pond scenario, while PRZM/EXAMS incorporate an index reservoir environment in place of the previous pond scenario. The PRZM/EXAMS model includes a percent crop area factor as an adjustment to account for the maximum percent crop coverage within a watershed or drainage basin.

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

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

Based on the GENEEC and SCI-GROW models the estimated environmental concentrations (EECs) of dimethenamid in surface water and ground water, for acute exposures are estimated to be 63.5 parts per billion (ppb) for surface water and 0.412 ppb for ground water. The EECs for chronic exposures are estimated to be 17 ppb for surface water and 0.412 ppb for ground water.

3. From non-dietary exposure. The term “residential exposure” is used in this document to refer to non-occupational, non-dietary exposure (e.g., for lawn and garden pest control, indoor pest control, termiticides, and flea and tick control on pets). Dimethenamid is not registered for use on any sites that would result in residential exposure.

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

EPA does not have, at this time, available data to determine whether dimethenamid has a common mechanism of toxicity with other substances or how to include this pesticide in a cumulative risk assessment. Unlike other pesticides for which EPA has followed a cumulative risk approach based on a common mechanism of toxicity, dimethenamid 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 dimethenamid has a common mechanism of toxicity with other substances. For information regarding EPA's efforts to determine which chemicals have a common mechanism of toxicity and to evaluate the cumulative effects of such chemicals, see the final rule for Bifenthrin Pesticide Tolerances November 26, 1997, (62 FR 62961) (FRL-5754-7).

C. Safety Factor for Infants and Children

1. Safety factor for infants and children—i. In general. FFDCA section 408 provides that EPA shall apply an additional tenfold margin of safety for infants and children in the case of threshold effects to account for pre-natal and post-natal toxicity and the completeness of the data base on toxicity and exposure unless EPA determines that a different margin of safety will be safe for infants and children. Margins of safety are incorporated into EPA risk assessments either directly through use of a MOE analysis or through using uncertainty (safety) factors in calculating a dose level that poses no appreciable risk to humans.

ii. Developmental toxicity studies. In a developmental toxicity study in rats, maternal toxicity was evidenced by excessive salivation, increased liver weight and reduced body weight gain and food consumption at 215 and 425 milligrams per kilogram per day (mg/kg/day). Developmental toxicity was evidenced by an increased incidence of resorption in the 425 mg/kg/day rats. The maternal NOAEL is 50 mg/kg/day and the maternal LOAEL is 215 mg/kg/day. The developmental NOAEL is 215 mg/kg/day and the developmental LOAEL is 425 mg/kg/day.

In a developmental toxicity study in rabbits, maternal toxicity was evidenced by decreased body weight, food consumption and increased abortion/premature delivery at 75 and 150 mg/Start Printed Page 51549kg/day. Developmental toxicity was evidenced by increased abortion/premature delivery and hyoid alae angulated changes in the 150 mg/kg group. The maternal NOAEL is 37.5 mg/kg/day and the maternal LOAEL is 75 mg/kg/day. The developmental NOAEL is 75 mg/kg/day and the developmental LOAEL is 150 mg/kg/day.

iii. Reproductive toxicity study. In a 2-generation reproductive study in rats, parental toxicity was evidenced by significant reductions in body weight and food consumption in males and significant increases in absolute and relative liver weights in both sexes. Significant reductions in pup weight during lactation occurred at 150 mg/kg/day. The parental NOAEL is 36 mg/kg/day and the parental LOAEL is 150 mg/kg/day. The reproduction NOAEL is 36 mg/kg/day and the reproduction LOAEL is 150 mg/kg/day.

iv. Conclusion. Based on the rat and rabbit developmental toxicity studies as well as the rat reproduction study, there did not appear to be an increase in the sensitivity of fetuses or offspring in relation to either maternal or parental toxicity. However, for purposes of these section 18 uses, the additional FQPA 10x safety factor was retained since the Agency's FQPA Safety Factor Committee has not assessed dimethnamid at this time.

D. Aggregate Risks and Determination of Safety

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

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

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

1. Acute risk. Using the exposure assumptions discussed in this unit for acute exposure, the acute dietary exposure from food to dimethenamid will occupy less than 1%% of the aPAD for the U.S. population, less than 1%% of the aPAD for females 13 years and older, less than 1%% of the aPAD for all infants and less than 1%% of the aPAD for all children. In addition, despite the potential for acute dietary exposure to dimethenamid in drinking water, after calculating DWLOCs and comparing them to conservative model estimated environmental concentrations of dimethenamid in surface and ground water. EPA does not expect the aggregate exposure to exceed 100%% of the aPAD, as shown in the following Table 2:

Table 2.— Aggregate Risk Assessment for Acute Exposure to Dimethenamid

Population subgroupaPAD (mg/kg)%% aPAD (Food)Surface water EEC (ppb)Ground water EEC (ppb)Acute DWLOC (ppb)
U.S. Population0.215Less than 1%%65.50.4127,500
Females (13-19 years old)0.215Less than 1%%65.50.4126,500
All Infants0.215Less than 1%%65.50.4122,200

2. Chronic risk. Using the exposure assumptions described in this unit for chronic exposure, EPA has concluded that exposure to dimethenamid from food will utilize less than 1%% of the cPAD for the U.S. population, 2%% of the cPAD for non-nursing infants (the most highly exposed infant subpopulation) and 1%% of the cPAD for children 1-6 years old (the most highly exposed children subpopulation). There are no registered residential uses for dimethenamid. In addition, despite the potential for chronic dietary exposure to dimethenamid in drinking water, after calculating the DWLOCs and comparing them to conservative model estimated environmental concentrations of dimethenamid in surface and ground water. EPA does not expect the aggregate exposure to exceed 100%% of the cPAD, as shown in the following Table 3.

Table 3.— Aggregate Risk Assessment for Chronic (non-Cancer) Exposure to Dimethenamid

Population subgroupcPAD mg/kg/day%% cPAD (Food)Surface water EEC (ppb)Ground Water EEC (ppb)Chronic DWLOC (ppb)
U.S. population0.005Less than 1%%170.412180
Non-Nursing infants0.0052%%170.41250
Children, 1-6 years old0.0051%%170.41249
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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). Dimethenamid is not registered for use on any sites that would result in residential exposure. Therefore, the aggregate risk is the sum of the risk from food and water, which were previously addressed.

4. Intermediate-term risk. intermediate-term aggregate exposure takes into account non-dietary, non-occupational exposure plus chronic exposure to food and water (considered to be a background exposure level). Dimethenamid is not registered for use on any sites that would result in residential exposure. Therefore, the aggregate risk is the sum of the risk from food and water, which were previously addressed.

5. Aggregate cancer risk for U.S. population. Dimethenamid has been classified as a Category “C” (possible human carcinogen). Based on increased tumor incidence only in rats (not mice). The Agency determined that a quantitative cancer risk assessment is not required. The RfD approach was used to estimate cancer risk. Therefore, the chronic (non-cancer) risk assessment, which was previously addressed, is adequately protective for cancer risk as well as other chronic effects.

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,and to infants and children from aggregate exposure to dimethenamid residues.

V. Other Considerations

A. Analytical Enforcement Methodology

Adequate analytical methodology is available to enforce the tolerance expression. Nitrogen Phosphorus Detection-Gas Liquid Chromatography (NPD-GLC) method (AM-0884-0193-1) has been submitted (7/89) for publication in the Pesticide Analytical Manual, Volume II, to enforce tolerances for residues of dimethenamid in/on plant and soil samples. The method may be requested from: Calvin Furlow, PRRIB, IRSD (7502C), Office of Pesticide Programs, Environmental Protection Agency, 1200 Pennsylvania Ave., NW, Washington, DC 20460; telephone number: (703) 305-5229; e-mail address: furlow.calvin@epa.gov.

B. International Residue Limits

There are no established Codex, Mexican, or Canadian maximum residue limits for dimethenamid in/on onions, dry bulb and sugar beet, tops and sugar beet, roots.

C. Conditions

A 30-day pre-harvest interval will be observed for dry bulb onions. No pre-harvest interval is required for sugar beets due to the timing of the applications.

VI. Conclusion

Therefore, the tolerance is established for residues of dimethenamid, 2-chloro-N-[(1-methyl-2-methoxy)ethyl]-N- (2,4-dimethylthien-3-yl)-acetamide, in or on dry bulb onions at 0.01 ppm, sugar beets roots and tops at 0.01 ppm and sugar beet dry pulp and molasses at 0.05 ppm.

VII. Objections and Hearing Requests

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. Although the procedures in those regulations require some modification to reflect the amendments made to the FFDCA by the FQPA of 1996, EPA will continue to use those procedures, with appropriate adjustments, until the necessary modifications can be made. The new section 408(g) provides essentially the same process for persons to “object” to a regulation for an exemption from the requirementof a tolerance issued by EPA under new section 408(d), as was provided in the old FFDCA sections 408 and 409. However, the period for filing objections is now 60 days, rather than 30 days.

A. What Do I Need to Do to File an Objection or Request a Hearing?

You must file your objection or request a hearing on this regulation in accordance with the instructions provided in this unit and in 40 CFR part 178. To ensure proper receipt by EPA, you must identify docket control number OPP-301038 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 23, 2000.

1. Filing the request. Your objection must specify the specific provisions in the regulation that you object to, and the grounds for the objections (40 CFR 178.25). If a hearing is requested, the objections must include a statement of the factual issues(s) on which a hearing is requested, the requestor's contentions on such issues, and a summary of any evidence relied upon by the objector (40 CFR 178.27). Information submitted in connection with an objection or hearing request may be claimed confidential by marking any part or all of that information as CBI. Information so marked will not be disclosed except in accordance with procedures set forth in 40 CFR part 2. A copy of the information that does not contain CBI must be submitted for inclusion in the public record. Information not marked confidential may be disclosed publicly by EPA without prior notice.

Mail your written request to: Office of the Hearing Clerk (1900), Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460. You may also deliver your request to the Office of the Hearing Clerk in Rm. C400, Waterside Mall, 401 M St.,SW., Washington, DC 20460. The Office of the Hearing Clerk is open from 8 a.m. to 4 p.m., Monday through Friday, excluding legal holidays. The telephone number for the Office of the Hearing Clerk is (202) 260-4865.

2. Tolerance fee payment. If you file an objection or request a hearing, you must also pay the fee prescribed by 40 CFR 180.33(i) or request a waiver of that fee pursuant to 40 CFR 180.33(m). You must mail the fee to: EPA Headquarters Accounting Operations Branch, Office of Pesticide Programs, P.O. Box 360277M, Pittsburgh, PA 15251. Please identify the fee submission by labeling it “Tolerance Petition Fees.”

EPA is authorized to waive any fee requirement “when in the judgement of the Administrator such a waiver or refund is equitable and not contrary to the purpose of this subsection.” For additional information regarding the waiver of these fees, you may contact James Tompkins by phone at (703) 305-5697, by e-mail at tompkins.jim@epa.gov, or by mailing a request for information to Mr. Tompkins at Registration Division (7505C), Office of Pesticide Programs, Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460.

If you would like to request a waiver of the tolerance objection fees, you must mail your request for such a waiver to: James Hollins, Information Resources and Services Division (7502C), Office of Pesticide Programs, Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460.

3. Copies for the Docket. In addition to filing an objection or hearing request with the Hearing Clerk as described in Unit VII.A., you should also send a copy of your request to the PIRIB for its inclusion in the official record that is described in Unit I.B.2. Mail your copies, identified by the docket control number OPP-301038, to: Public Start Printed Page 51551Information and Records Integrity Branch, Information Resources and Services Division (7502C), Office of Pesticide Programs, Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460. In person or by courier, bring a copy to the location of the PIRIB described in Unit I.B.2. You may also send an electronic copy of your request via e-mail to: opp-docket@epa.gov. Please use an ASCII file format and avoid the use of special characters and any form of encryption. Copies of electronic objections and hearing requests will also be accepted on disks in WordPerfect 6.1/8.0 file format or ASCII file format. Do not include any CBI in your electronic copy. You may also submit an electronic copy of your request at many Federal Depository Libraries.

B. When Will the Agency Grant a Request for a Hearing?

A request for a hearing will be granted if the Administrator determines that the material submitted shows the following: There is a genuine and substantial issue of fact; there is a reasonable possibility that available evidence identified by the requestor would, if established resolve one or more of such issues in favor of the requestor, taking into account uncontested claims or facts to the contrary; and resolution of the factual issues(s) in the manner sought by the requestor would be adequate to justify the action requested (40 CFR 178.32).

VIII. Regulatory Assessment Requirements

This final rule establishes time limited tolerances under FFDCA section 408. 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). 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., or 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). Nor does it require any prior consultation as specified by Executive Order 13084, entitled Consultation and Coordination with Indian Tribal Governments (63 FR 27655, May 19, 1998); special considerations as required by Executive Order 12898, entitled Federal Actions to Address Environmental Justice in Minority Populations and Low-Income Populations (59 FR 7629, February 16, 1994); or require OMB review or any Agency action under Executive Order 13045, entitled Protection of Children from Environmental Health Risks and Safety Risks (62 FR 19885, April 23, 1997). 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). Since tolerances and exemptions that are established on the basis of a FIFRA section 18 exemption under FFDCA section 408, such as the tolerances 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. In addition, the Agency has determined that this action will not have a substantial direct effect on States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government, as specified in Executive Order 13132, entitled Federalism, August 10, 1999 (64 FR 43255). Executive Order 13132 requires EPA to develop an accountable process to ensure “meaningful and timely input by State and local officials in the development of regulatory policies that have federalism implications.” “Policies that have federalism implications” is defined in the Executive Order to include regulations that have “substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government.” This final rule directly regulates growers, food processors, food handlers and food retailers, not States. This action does not alter the relationships or distribution of power and responsibilities established by Congress in the preemption provisions of FFDCA section 408(n)(4).

IX. Submission to Congress and the Comptroller General

The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the Small Business Regulatory Enforcement Fairness Act of 1996, generally provides that before a rule may take effect, the agency promulgating the rule must submit a rule report, which includes a copy of the rule, 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).

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List of Subjects in 40 CFR Part 180

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August 15, 2000.

Peter Caulkins,

Acting Director, Registration Division, Office of Pesticide Programs.

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Therefore, 40 CFR chapter I is amended as follows:

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PART 180— [AMENDED]

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

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

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2. Section 180.464 is revised to read as follows:

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Dimethenamid, 2-chloro-N-[(1-methyl-2-methoxy)ethyl]-N-(2,4-dimethylthien-3-yl)-acetamide

(a) General. Tolerances are established for residues of the herbicide dimethenamid, 1(R,S)-2-chloro-N-[(1-methyl-2-methoxy)ethyl]-N-(2,4-dimethylthien-3-yl)-acetamide in or on the following food commodities:

CommodityParts per million
Beans, dry0.01
Corn, fodder0.01
Corn, forage0.01
Corn, grain0.01
Corn, sweet, fodder (stover)0.01
Corn, sweet, forage0.01
Corn, sweet (kernels plus cobs with husks removed)0.01
Peanut, hay0.01
Peanut, nutmeat0.01
Sorghum, grain, fodder0.01
Sorghum, grain, forage0.01
Sorghum, grain0.01
Soybeans0.01

(b) Section 18 emergency exemptions. Time-limited tolerances are established for residues of the herbicide dimethenamid in connection with the use of the pesticide under section 18 emergency exemptions granted by EPA. These tolerances will expire and are revoked on the dates specified in the following table. Start Printed Page 51552

CommodityParts per millionExpiration/revocation date
Beet, sugar0.0112/31/02
Beet, sugar, dried pulp0.0512/31/02
Beet, sugar, molasses0.0512/31/02
Beet, sugar, tops0.0112/31/02
Onion, dry bulb0.0112/31/02

(c) Tolerances with regional registrations. [Reserved]

(d) Indirect or inadvertent residues. [Reserved]

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[FR Doc. 00-21672 Filed 8-23-00; 8:45 am]

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