[Federal Register Volume 65, Number 165 (Thursday, August 24, 2000)]
[Rules and Regulations]
[Pages 51544-51552]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-21672]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[OPP-301038; FRL-6738-1]
RIN 2070-AB78


Dimethenamid; Pesticide Tolerances for Emergency Exemptions

AGENCY:  Environmental Protection Agency (EPA).

ACTION:  Final rule.

-----------------------------------------------------------------------

SUMMARY:  This regulation establishes time-limited tolerances for 
residues of

[[Page 51545]]

dimethenamid, 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.

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: 
[email protected].

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:

 
------------------------------------------------------------------------
                                                 Examples of Potentially
             Categories                 NAICS       Affected Entities
------------------------------------------------------------------------
Industry                                    111  Crop production
                                            112  Animal production
                                            311  Food manufacturing
                                          32532  Pesticide 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,

[[Page 51546]]

it 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  x  10-6 or one in a million). 
Under certain specific

[[Page 51547]]

circumstances, 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
----------------------------------------------------------------------------------------------------------------
                                                                 FQPA SF* and level of
          Exposure scenario               Dose used in risk         concern for risk     Study and toxicological
                                            assessment, UF             assessment                effects
----------------------------------------------------------------------------------------------------------------
Acute dietary females 13-50 years of   NOAEL = 215 mg/kg/day;   FQPA SF = 10x; aPAD =    Developmental toxicity,
 age                                    UF = 100; Acute RfD =    acute RfD        rat; LOAEL is 425 mg/
                                        2.15 mg/kg/day           FQPA SF = 0.215 mg/kg/   kg/day based on early
                                                                 day                      resorption.
----------------------------------------------------------------------------------------------------------------
Acute Dietary general population       NOAEL = 215 mg/kg/day;   FQPA SF = 10x aPAD =     Developmental toxicity,
 including infants and children         UF = 100; Acute RfD =    acute RfD        rat; LOAEL is 425 mg/
                                        2.15 mg/kg/day           FQPA SF = 0.215 mg/kg/   kg/day based on early
                                                                 day                      resorption.
----------------------------------------------------------------------------------------------------------------
Chronic dietary all populations        NOAEL = 5.1 mg/kg/day;   FQPA SF = 10x; cPAD =    Chronic rat study;
                                        UF = 100; Chronic RfD    chronic RfD      LOAEL is 36 mg/kg/day
                                        = 0.05 mg/kg/day         FQPA SF = 0.005 mg/kg/   (males) based on
                                                                 day                      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)        None                     None                     None
 (residential)
----------------------------------------------------------------------------------------------------------------
intermediate-Term dermal (1 week to    None                     None                     None
 several months) (residential)
----------------------------------------------------------------------------------------------------------------
long-Term dermal (several months to    None                     None                     None
 lifetime) (residential)
----------------------------------------------------------------------------------------------------------------
Short-Term Inhalation (1 to 7 days)    None                     None                     None
 (residential)
----------------------------------------------------------------------------------------------------------------
intermediate-Term Inhalation (1 week   None                     None                     None
 to several months) (residential)
----------------------------------------------------------------------------------------------------------------
long-Term Inhalation (several months   None                     None                     None
 to lifetime) (residential)
----------------------------------------------------------------------------------------------------------------
Cancer (oral, dermal, inhalation)      NOAEL = 5.1 mg/kg/day;   Category ``C''           Chronic rat study;
                                        UF = 100; Chronic RfD    (possible human          increased tumor
                                        = 0.05 mg/kg/day         carcinogen)              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-

[[Page 51548]]

use pesticide if a toxicological study has indicated the possibility of 
an effect of concern occurring as a result of a one day or single 
exposure. 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/

[[Page 51549]]

kg/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
----------------------------------------------------------------------------------------------------------------
                                                                             Surface       Ground
        Population subgroup           aPAD (mg/        % aPAD (Food)        water EEC    water EEC   Acute DWLOC
                                         kg)                                  (ppb)        (ppb)        (ppb)
----------------------------------------------------------------------------------------------------------------
U.S. Population                            0.215             Less than 1%         65.5        0.412        7,500
Females (13-19 years old)                  0.215             Less than 1%         65.5        0.412        6,500
All Infants                                0.215             Less than 1%         65.5        0.412        2,200
----------------------------------------------------------------------------------------------------------------

    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
----------------------------------------------------------------------------------------------------------------
                                                                             Surface       Ground
        Population subgroup          cPAD mg/kg/       % cPAD (Food)        water EEC    Water EEC     Chronic
                                         day                                  (ppb)        (ppb)     DWLOC (ppb)
----------------------------------------------------------------------------------------------------------------
U.S. population                            0.005             Less than 1%           17        0.412          180
Non-Nursing infants                        0.005                       2%           17        0.412           50
Children, 1-6 years old                    0.005                       1%           17        0.412           49
----------------------------------------------------------------------------------------------------------------


[[Page 51550]]

    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: [email protected].

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 [email protected], 
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

[[Page 51551]]

Information 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: [email protected]. 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).

List of Subjects in 40 CFR Part 180

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

    August 15, 2000.
Peter Caulkins,
Acting Director, Registration Division, Office of Pesticide Programs.

    Therefore, 40 CFR chapter I is amended as follows:

PART 180-- [AMENDED]

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

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


    2. Section 180.464 is revised to read as follows:


Sec. 180.464  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:

 
------------------------------------------------------------------------
                                                              Parts per
                         Commodity                             million
------------------------------------------------------------------------
Beans, dry.................................................         0.01
Corn, fodder...............................................         0.01
Corn, forage...............................................         0.01
Corn, grain................................................         0.01
Corn, sweet, fodder (stover)...............................         0.01
Corn, sweet, forage........................................         0.01
Corn, sweet (kernels plus cobs with husks removed).........         0.01
Peanut, hay................................................         0.01
Peanut, nutmeat............................................         0.01
Sorghum, grain, fodder.....................................         0.01
Sorghum, grain, forage.....................................         0.01
Sorghum, grain.............................................         0.01
Soybeans...................................................         0.01
------------------------------------------------------------------------

    (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.

[[Page 51552]]



 
------------------------------------------------------------------------
                                                            Expiration/
                 Commodity                    Parts per     revocation
                                               million         date
------------------------------------------------------------------------
Beet, sugar................................         0.01        12/31/02
Beet, sugar, dried pulp....................         0.05        12/31/02
Beet, sugar, molasses......................         0.05        12/31/02
Beet, sugar, tops..........................         0.01        12/31/02
Onion, dry bulb............................         0.01        12/31/02
------------------------------------------------------------------------

    (c) Tolerances with regional registrations. [Reserved]
    (d) Indirect or inadvertent residues. [Reserved]

[FR Doc. 00-21672 Filed 8-23-00; 8:45 am]
BILLING CODE 6560-50-S