[Federal Register Volume 64, Number 46 (Wednesday, March 10, 1999)]
[Rules and Regulations]
[Pages 11792-11799]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-5961]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
[OPP-300800; FRL-6065-3]
RIN 2070-AB78
2,4-D; Time-Limited Pesticide Tolerance
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
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SUMMARY: This regulation establishes a time-limited tolerance for
residues of 2,4-dichlorophenoxyacetic acid in or on soybeans. Industry
Task Force II on 2,4-D Research Data requested this tolerance under the
Federal Food, Drug, and Cosmetic Act, as amended by the Food Quality
Protection Act of 1996. The tolerance will expire on December 31, 2001.
DATES: This regulation is effective March 10, 1999. Objections and
requests for hearings must be received by EPA on or before May 10,
1999.
ADDRESSES: Written objections and hearing requests, identified by the
docket control number [OPP-300800], must be submitted to: Hearing Clerk
(1900), Environmental Protection Agency, Rm. M3708, 401 M St., SW.,
Washington, DC 20460. Fees accompanying objections and hearing requests
shall be labeled ``Tolerance Petition Fees'' and forwarded to: EPA
Headquarters Accounting Operations Branch, OPP (Tolerance Fees), P.O.
Box 360277M, Pittsburgh, PA 15251. A copy of any objections and hearing
requests filed with the Hearing Clerk identified by the docket control
number, [OPP-300800], must also be submitted to: Public Information and
Records Integrity Branch, Information Resources and Services Division
(7502C), Office of Pesticide Programs, Environmental Protection Agency,
401 M St., SW., Washington, DC 20460. In person, bring a copy of
objections and hearing requests to Rm. 119, Crystal Mall 2 (CM #2),
1921 Jefferson Davis Hwy., Arlington, VA.
A copy of objections and hearing requests filed with the Hearing
Clerk may also be submitted electronically by sending electronic mail
(e-mail) to: opp-docket@epa.gov. Copies of electronic objections and
hearing requests must be submitted as an ASCII file avoiding the use of
special characters and any form of encryption. Copies of objections and
hearing requests will also be accepted on disks in WordPerfect 5.1/6.1
or ASCII file format. All copies of electronic objections and hearing
requests must be identified by the docket control number [OPP-300800].
No Confidential Business Information (CBI) should be submitted through
e-mail. Copies of electronic objections and hearing requests on this
rule may be filed online at many Federal Depository Libraries.
FOR FURTHER INFORMATION CONTACT: By mail: Joanne I. Miller,
Registration Division (7505C), Office of Pesticide Programs,
Environmental Protection Agency, 401 M St., SW., Washington, DC 20460.
Office location, telephone number, and e-mail address: Rm. 235, CM #2,
1921 Jefferson Davis Hwy., Arlington, VA, 703-305-6224,
miller.joanne@epa.gov.
SUPPLEMENTARY INFORMATION: In the Federal Register of December 11, 1998
(63 FR 68455) (FRL-6043-3), EPA issued a notice pursuant to section 408
of the Federal Food, Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 346a, as
amended by the Food Quality Protection Act of 1996 (FQPA) (Pub. L. 104-
170) announcing the filing of a pesticide petition (PP) for tolerance
by Industry Task Force II on 2,4-D Research Data, McKenna & Cuneo, 1900
K St., NW, Washington, DC 20006-1108. This notice included a summary of
the petition prepared by Industry Task Force II on 2,4-D Research Data,
the registrant. There were no comments received in response to the
notice of filing.
The petition requested that 40 CFR 180.142 be amended by
establishing a time-limited tolerance for residues of the herbicide
2,4-dichlorophenoxyacetic acid, in or on soybeans at 0.02 part per
million (ppm). This tolerance will expire on December 31, 2001.
I. Background and Statutory Findings
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. . . .''
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).
II. Aggregate Risk Assessment and Determination of Safety
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 2,4-D and
to make a determination on aggregate exposure, consistent with section
408(b)(2), for a time-limited tolerance for residues of 2,4-
dichlorophenoxyacetic acid on soybeans at 0.02 ppm. EPA's assessment of
the dietary exposures and risks associated with establishing the
tolerance follows.
A. Toxicological Profile
EPA has evaluated the available toxicity data and considered its
validity, completeness, and reliability as well as the relationship of
the results of the studies to human risk. EPA has also considered
available information concerning the variability of the sensitivities
of major identifiable subgroups of consumers, including infants and
children. The nature of the toxic effects caused by 2,4-D are discussed
in this unit.
An oral LD50 of 2,4-D acid is 699 miligrams/kilograms
(mg/kg) in the rat.
[[Page 11793]]
The dermal LD50 in the rabbit is >2000 mg/kg. The acute
inhalation LC50 in the rat is >1.8 mg/liter. A primary eye
irritation study in the rabbit showed severe irritation. A dermal
irritation study in the rabbit showed moderate irritation. A dermal
sensitization study in the guinea pig showed no skin sensitization. An
acute neurotoxicity study in the rat produced a no observed advers
effect level (NOAEL) of 227 mg/kg for systemic toxicity and a
neurobehavioral NOAEL of 67 mg/kg with a lowest observed effect level
(LOEL) of 227 mg/kg.
Mutagenicity studies including gene mutation, chromosomal
aberrations, and direct DNA damage tests were negative for mutagenic
effects.
A 2-generation reproduction study was conducted in rats with
NOAELs for parental and developmental toxicity of 5 mg/kg/day. The
LOELs for this study are established at 20 mg/kg/day based on
reductions in body weight gain in F0 and F2b
pups, and reduction in pup weight at birth and during lactation. A
teratology study in rabbits given gavage doses at 0, 10, 30, and 90 mg/
kg on days 6 through 18 of gestation was negative for developmental
toxicity at all doses tested. A teratology study in rats given gavage
doses at 0, 8, 25, and 75 mg/kg on days 6 through 15 of gestation was
negative for developmental toxicity at all doses tested. A NOAEL for
fetotoxicity was established at 25 mg/kg/day based on delayed
ossification at the 75 mg/kg dose level. The effects on pups occurred
in the presence of parental toxicity.
A subchronic dietary study was conducted with mice fed diets
containing 0, 1, 15, 100, and 300 mg/kg/day with a NOAEL of 15 mg/kg/
day. The LOEL was established at 100 mg/kg/day based on decreased
glucose and thyroxine levels, increases in absolute and relative kidney
weights, and histopathological lesions in the liver and kidneys. A 90-
day dietary study in rats fed diets containing 0, 1, 15, 100, or 300
mg/kg/day resulted in a NOAEL of 15 mg/kg/day and an LOEL of 100 mg/kg/
day. The LOEL was based on decreases in body weight and food
consumption, alteration in clinical pathology, changes in organ
weights, and histopathological lesions in the kidney, liver, and
adrenal glands of both sexes of rats. A 90-day feeding study was
conducted in dogs fed diets containing 0, 0.3, 1, 3, and 10 mg/kg/day
with a NOAEL of 1 mg/kg/day. The LOEL was established at 3 mg/kg/day
based on histopathological changes in the kidneys of male dogs.
A 1-year dietary study was conducted in the dog using doses of 0,
1, 5, and 7.5 mg/kg/day. The NOAEL was 1 mg/kg/day and the LOEL was 5
mg/kg/day based on clinical chemistry changes and histopathological
lesions in the liver and kidney. A 2-year feeding/carcinogenicity study
was conducted in mice fed diets containing 0, 1, 15, and 45 mg/kg/day
with a NOAEL of 1 mg/kg/day. The systemic LOEL was established at 15
mg/kg/day based on increased kidney and adrenal weights and homogeneity
of renal tubular epithelium due to cytoplasmic vacuoles. No
carcinogenic effects were observed under the conditions of the study at
any dosage level tested. A second 2-year oncogenicity study was
conducted in mice fed diets containing 0, 5, 62.5, and 125 mg/kg/day
(males) and 0, 5, 150, and 300 mg/kg/day (females). No treatment-
related oncogenicity was observed. A 2-year feeding/carcinogenicity
study was conducted in rats fed diets containing 0, 1, 15, and 45 mg/
kg/day with a NOAEL of 1 mg kg/day. Although there appeared to be a
slight treatment-related incidence of benign brain tumors
(astrocytomas) in male rats fed diets containing 45 mg/kg/ day, two
different statistical evaluations found no strong statistical evidence
of carcinogenicity in male rats. There were no carcinogenic effects
observed in female rats. A second 2-year feeding/carcinogenicity study
was conducted in rats fed diets containing 0, 5, 75, and 150 mg/kg/day.
The NOAEL was 5 mg/kg/day and the LOEL was 75 mg/kg/day based on
decreased body weight, body weight gain and food consumption; clinical
chemistry changes; organ weight changes and histopathological lesions.
No treatment-related carcinogenic effects or increased incidences of
astrocytomas were observed.
The metabolism of phenyl ring labeled 14C-2,4-D was
studied in the rat following a single intravenous or oral dose of
approximately 1 mg/kg/day. At 48 hours after treatment, recovery of
radioactivity in urine was in excess of 98%. Parent 2,4-D was the major
metabolite (72.9% to 90.5%) found in the urine.
B. Toxicological Endpoints
1. Acute toxicity. EPA has used an acute neurotoxicity study in
rats for endpoint for acute toxicity. The NOAEL of 67 mg/kg/day was
based on the increased incidence of incoordination, slight gait
abnormalities, and decreased motor activity in both sexes at the lowest
observed adverse effect (LOAEL) of 227 mg/kg/day. This risk assessment
will evaluate acute dietary risk to all population subgroups.
2. Short - and intermediate-term toxicity. For short-term dermal
Margin of Exposure (MOE) calculations, EPA used the maternal NOAEL of
30 mg/kg/day from an oral developmental toxicity study in rabbits. The
MOE is a measure of how close the high end of exposure comes to the
NOAEL (or LOAEL, as the case may be) and is calculated as the ratio of
the NOAEL to the exposure. The LOAEL of 90 mg/kg/day was based on
abortions, clinical signs (ataxia, decreased motor activity, and cold
extremities during gestation), and decreased body weight gain. For
acute toxicity, EPA decided that FQPA factor of 10 should be reduced to
3 for females 13 years old and older (13+) and removed for all other
population subgroups. As the short-term and acute endpoints are based
on the oral developmental toxicity study, this decision is also
applicable to the short-term, nonoccupational assessment. Therefore,
based on this recommendation, the MOE needed for females 13+ is 300.
For intermediate-term dermal MOE calculations, EPA used the NOAEL
of 1.0 mg/kg/day from a 90-day oral toxicity study in dogs. The LOAEL
of 3 mg/kg/day was based on clinical chemistry changes (increased BUN
and creatinine levels) and lesions in the kidneys. An MOE of 100 is
required.
3. Chronic toxicity. EPA has established the RfD for 2,4-D at 0.01
mg/kg/day. This RfD is based on a 1-year oral toxicity study in dogs
with a NOAEL of 1 mg/kg/day and an uncertainty factor (UF) of 100,
based on alterations in serum chemistry with corroborative
histopathological lesions in the liver and kidneys.
4. Carcinogenicity. EPA has classified 2,4-D as a Group D chemical
(``not classifiable as to human carcinogenicity'') on the basis that
``the evidence is inadequate and cannot be interpreted as showing
either the presence or absence of a carcinogenic effect''.
C. Exposures and Risks
1. From food and feed uses. Tolerances have been established (40
CFR 180.142) for the residues of 2,4-dichlorophenoxyacetic acid, in or
on a variety of raw agricultural commodities. A time limited tolerance
of 0.1 ppm was previously established for residues of 2,4-D on soybeans
resulting from the preplant use of 2,4-D ester or amine 40 CFR
180.142(a)(11). In order for EPA to recommend favorably for the
establishment of permanent tolerances on soybeans, additional field
trial data and processing data were required. In response, the Industry
Task Force II on
[[Page 11794]]
2,4-D Research Data (Task Force II) submitted field residue data on
soybeans. EPA reviewed these data and concluded that a tolerance of
0.02 ppm was appropriate for soybean seed. Task Force II has thus
proposed to extend the soybean tolerance to December 31, 2001 at a
level of 0.02 ppm. Risk assessments were conducted by EPA to assessed
dietary exposures from 2,4-D as follows:
i. Acute exposure and risk. Acute dietary risk assessments are
performed for a food-use pesticide if a toxicological study has
indicated the possibility of an effect of concern occurring as a result
of a 1-day or single exposure. The Dietary Exposure Evaluation Model
(DEEM ) analysis evaluated the individual food consumption as reported
by respondents in the USDA 1989-91 Nationwide Continuing Surveys for
Food Intake by Individuals (CSFII) and accumulated exposure to the
chemical for each commodity. Each analysis assumes uniform distribution
of 2,4-D in the commodity supply.
The acute exposure analysis for all subgroup was performed using
anticipated and tolerance-level residues and 100 percent crop treated.
The high end MOE for the subgroup of Females (13+) was 399, and is no
cause for concern given the need of a MOE of 300. The high end MOEs for
the remaining populations ranged from 214 (infants less than one year
old) to 321 (overall U.S. population, 48 states), and demonstrate no
cause for concern given the need of a MOE of 100. Therefore, EPA does
not consider the acute food risk to exceed the level of concern.
ii. Chronic exposure and risk. A chronic dietary risk assessment
was performed for 2,4-D using the RfD for the chronic dietary analysis
of 0.01 mg/kg bwt/day. Chronic dietary exposure estimates (DEEM ) used
mean consumption (3 day average) and anticipated or tolerance-level
residues for all commodities. Exposure estimates used 25.6% of the RfD
for the general U.S. population (48 states) and 49.2% of the RfD for
the most exposed population of non-nursing infants (less than one year
old). Since estimated exposures did not exceed the RfD for any
subgroup, EPA does not consider the chronic food risk to exceed the
level of concern.
2. From drinking water. A Maximum Contaminant Level (MCL) of 0.07
mg/L and Health Advisories (HAs) as follows are established for 2,4-D
in drinking water: for a 10-kg child, a range of 1 mg/L from 1-day
exposure to 0.1 mg/L for longer-term exposure up to 7 years; for a 70-
kg adult, a range of 0.4 mg/L for longer-term exposure to 0.07 mg/L for
lifetime exposure.
Information in the Pesticides in Groundwater Database (EPA 734-12-
92-001, 9/92) indicates that 6,142 wells in 32 States were sampled for
residues of 2,4-D during the period 1979-91. Detectable residues were
reported (0.0079-57.1 g/L) in 2.3% (139) of those sampled wells.
An FQPA water assessment was conducted by the Environmental Fate
and Effects Division (EFED) to support an FQPA tolerance reassessment
for the use of 2,4-D dimethylamine salt (DMA), 2,4-D ethylhexyl ester
(EHE), and 2,4-D (acid) as a soybean burndown product. Since laboratory
environmental fate data indicate that 2,4-D DMA and 2,4-D EHE degrade
rapidly to form 2,4-D, the water assessment is focused on the
environmental fate and transport of the 2,4-D. The strategy assumes
that the 2,4-D DMA and 2,4-EHE are not persistent in the environment,
and the environmental fate of these compounds is dependent on the fate
properties of the degradate 2,4-D.
It is noteworthy that water treatment processes affect the removal
of 2,4-D from raw water (Versar, 1992). These treatments include
granulated activated carbon (70-100% removal), packed tower aeration
(0-29% removal), and ozone oxidation (30-69% removal).
A review of the labels indicate that the highest single application
rate in terrestrial environments (e.g., terrestrial noncrop and
terrestrial crop use patterns) for 2,4-D occur at 3.74 pounds of active
ingredient per acre (lbs ai/A), for 2,4-D EHE occur at 10 lbs ai/A, and
for 2,4-D DMA occur at 2 lbs ai/A. These rates represent seasonal
maximum application rates as part of 2,4-D exposure reduction agreement
to support 2,4-D use on pasture/rangeland, forestry, and residential
and turf (excluding sod farm) sites. It is noteworthy that the 10 lbs
ai/A rate corresponds to a basal bark spot treatment. Since this type
of application cannot be simulated from Tier 1 models, EFED conducted
modeling on the label rate from the 2,4-D label.
For groundwater, SCIGROW modeling indicates that the 2,4-D
concentration in ground water is not likely to exceed 0.014 g/
L for both peak (acute) and annual average (chronic) concentration.
Since this estimation was less than the actual monitoring
concentrations noted above, the actual monitoring concentrations were
used in the risk assessment.
For surface water estimates were made using the generic expected
environmental concentration (GENEEC) model. GENEEC modeling indicates
that 2,4-D concentrations in raw surface water are not likely to exceed
132 g/L for annual peak (acute) and 48 g/L for 56 day
average (chronic) concentrations. Since Office of Pesticide Program
(OPP) policy recommends that the 90/56-day GENEEC value be divided by 3
to obtain a value for chronic risk assessment calculations, the surface
water value for use in the chronic risk assessment would be 16 ppb or
g/L.
A Drinking Water Level of Comparison (DWLOC) is a theoretical upper
limit on a pesticide's concentration in drinking water in light of
total aggregate exposure to a pesticide in food, drinking water, and
through residential uses. A DWLOC will vary depending on the toxic
endpoint, with drinking water consumption, and body weights. Different
populations will have different DWLOCs. OPP uses DWLOCs internally in
the risk assessment process as a surrogate measure of potential
exposure associated with pesticide exposure through drinking water. In
the absence of monitoring data for pesticides, it is used as a point of
comparison against conservative model estimates of a pesticide's
concentration in water. DWLOC values are not regulatory standards for
drinking water. They do have an indirect regulatory impact through
aggregate exposure and risk assessments. Because EPA 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, EPA
will reassess the potential impacts of 2,4-D on drinking water as a
part of the aggregate risk assessment process.
i. Acute exposure and risk. EPA has calculated drinking water
levels of comparison (DWLOCs) for acute exposure to 2,4-D in drinking
water for the females (13+ years old, nursing) to be 1700 ppb. To
calculate the DWLOC for acute exposure relative to an acute toxicity
endpoint, the acute dietary food exposure (from the DEEM analysis) was
subtracted from the RfD to obtain the acceptable acute exposure to 2,4-
D in drinking water. DWLOCs were then calculated using default body
weights and drinking water consumption figures. EPA has determined that
the maximum estimated concentrations of 2,4-D in surface and/or ground
water is not likely to exceed EPA's levels of consideration for 2,4-D
in drinking water as a contribution to acute exposure. EPA concludes
with reasonable certainty that residues of 2,4-D in drinking water
(when considered along with other sources of exposure for which EPA has
reliable data) would not result in unacceptable levels of aggregate
human health risk at this time.
[[Page 11795]]
ii. Chronic exposure and risk. For chronic (non-cancer), the
drinking water levels of concern are 260 and 51 ppb for the U.S.
population and non-nursing infants (less than 1 year old),
respectively. To calculate the DWLOC for chronic (non-cancer, cancer)
exposure relative to a chronic toxicity endpoint, the chronic dietary
food exposure (from DEEM) was subtracted from the RfD to obtain the
acceptable chronic (non-cancer) exposure to 2,4-D in drinking water.
DWLOCs were then calculated using default body weights and drinking
water consumption figures. EPA has determined that the maximum
estimated concentrations of 2,4-D in surface and/or ground water is not
likely to exceed EPA's levels of consideration for 2,4-D in drinking
water as a contribution to chronic aggregate exposure. EPA concludes
with reasonable certainty that residues of 2,4-D in drinking water
(when considered along with other sources of exposure for which EPA has
reliable data) would not result in unacceptable levels of aggregate
human health risk at this time.
Section 408(b)(2)(E) authorizes EPA to use available data and
information on the anticipated residue levels of pesticide residues in
food and the actual levels of pesticide chemicals that have been
measured in food. If EPA relies on such information, EPA must require
that data be provided 5 years after the tolerance is established,
modified, or left in effect, demonstrating that the levels in food are
not above the levels anticipated. Following the initial data
submission, EPA is authorized to require similar data on a time frame
it deems appropriate. As required by section 408(b)(2)(E), EPA will
issue a data call-in for information relating to anticipated residues
to be submitted no later than 5 years from the date of issuance of this
tolerance.
3. From non-dietary exposure. 2,4-D is currently registered for use
on the following residential non-food sites: ornamental turf, lawns,
and grasses, golf course turf, recreational areas, and several other
indoor and outdoor uses. There are chemical-specific and site-specific
data available to determine the potential risks associated with
residential exposures from the registered uses of 2,4-D. Dislodgeable
residues of 2,4-D taken during exposure sessions showed a rapid decline
from 1 hour following application (8%) to 24 hours following
applications (1%). No detectable residues were found in urine samples
supplied by volunteers exposed to sprayed turf 24 hours following
application. Intermediate-term postapplication exposure is thus not
expected. The following assessments are based on the available chemical
specific data.
i. Chronic exposure and risk. Although a chronic endpoint was
chosen, this risk assessment is not required because there is no
chronic exposure scenario for this use.
ii. Short- and intermediate-term exposure and risk. For short-term
dermal MOE calculations, EPA used the maternal NOAEL of 30 mg/kg/day
from the oral developmental toxicity study in rabbits. The LOAEL of 90
mg/kg/day was based on abortions, clinical signs (ataxia, decreased
motor activity, and cold extremities during gestation), and decreased
body weight gain. For acute toxicity, EPA reduce the FQPA factor of 10
to 3 for females 13+ and removed for all other population subgroups. As
the short-term and acute endpoints are based on the oral developmental
toxicity study, this decision is also applicable to the short-term,
nonoccupational assessment. Therefore, based on this recommendation,
the MOE needed for females 13+ is 300.
For intermediate-term dermal MOE calculations, EPA used the NOAEL
of 1.0 mg/kg/day from the 90-day oral toxicity study in dogs. The LOAEL
of 3 mg/kg/day was based on clinical chemistry changes (increased BUN
and creatinine levels) and lesions in the kidneys. An MOE of 100 is
required.
4. Cumulative exposure to substances with 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 2,4-D 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, 2,4-D 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
2,4-D 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
(62 FR 62961, November 26, 1997).
D. Aggregate Risks and Determination of Safety for U.S. Population
1. Acute risk. The acute dietary MOE was calculated to be 321 for
the U.S. population and 399 for females 13+ years/nursing (accounts for
both maternal and fetal exposure). These MOE calculations were based on
the acute neurotoxicity NOAEL of 67 mg/kg/day. This risk assessment
assumed 100% crop-treated with anticipated (blended commodities) or
tolerance-level residues on all treated crops consumed, resulting in a
significant over estimation of dietary exposure. The acute dietary MOE
calculated for the U.S. population and for females 13+ years/nursing
provides assurance that there is a reasonable certainty of no harm for
acute exposure to 2,4-D.
The maximum estimated concentrations of 2,4-D in surface and ground
water are less than EPA's DWLOCs for 2,4-D as a contribution to acute
aggregate exposure. Therefore, EPA concludes with reasonable certainty
that residues of 2,4-D in drinking water do not contribute
significantly to the aggregate acute human health risk at the present
time considering the present uses and uses proposed in this action.
EPA bases this determination on a comparison of estimated
concentrations of 2,4-D in surface waters and ground waters to levels
of comparison for 2,4-D in drinking water. The estimates of 2,4-D in
surface and ground waters are derived from water quality models that
use conservative assumptions regarding the pesticide transport from the
point of application to surface and ground water. Because EPA considers
the aggregate risk resulting from multiple exposure pathways associated
with a pesticide's uses, DWLOCs may vary as those uses change. If new
uses are added in the future, EPA will reassess the potential impacts
of 2,4-D on drinking water as a part of the aggregate acute risk
assessment process.
2. Chronic risk. Using the ARC exposure assumptions described in
this unit, EPA has concluded that aggregate exposure to 2,4-D from food
will utilize 26% of the RfD for the U.S. population. The major
identifiable subgroup with the highest aggregate exposure is discussed
below. EPA generally has no concern for exposures below 100% of the RfD
because the RfD represents the level at or below which daily aggregate
dietary exposure over a lifetime will not pose appreciable risks to
human health. Despite the potential for exposure to 2,4-D in drinking
water and from non-dietary, non-occupational exposure, EPA does not
expect the aggregate
[[Page 11796]]
exposure to exceed 100% of the RfD. EPA concludes that there is a
reasonable certainty that no harm will result from aggregate exposure
to 2,4-D residues.
3. Short- and intermediate-term risk. Short- and intermediate-term
aggregate exposure takes into account chronic dietary food and water
(considered to be a background exposure level) plus indoor and outdoor
residential exposure.
The short-term NOAEL for dermal exposure is based on the maternal
NOAEL of 30 mg/kg/day from the oral developmental toxicity study in
rabbits. After factoring in residential exposure, the high end total
MOE for females 13+ was 750, and does not exceed EPA's level of
concern.
The intermediate-term NOAEL for dermal exposure is based on the
NOAEL of 1.0 mg/kg/day from the 90-day oral toxicity study in dogs. As
homeowner use of 2,4-D is not expected to result in intermediate-term
dermal exposure, only dietary and water exposures need to be considered
in this assessment.
There is a potential for short- and intermediate-term exposure from
drinking water. However, as estimated average concentrations of 2,4-D
in surface and ground water are less than EPA's levels of concern for
drinking water as a contribution to chronic aggregate and acute
aggregate exposures, contribution to short- and intermediate-term
exposure should not exceed EPA's levels of concern.
4. Aggregate cancer risk for U.S. population. EPA has classified
2,4-D as a Group D chemical (``not classifiable as to human
carcinogenicity'') on the basis that ``the evidence is inadequate and
cannot be interpreted as showing either the presence or absence of a
carcinogenic effect.'' Based on these risk assessments, EPA concludes
that there is a reasonable certainty that no harm will result from
aggregate exposure to 2,4-D residues.
5. Determination of safety. Based on these risk assessments, EPA
concludes that there is a reasonable certainity that no harm will
result from aggregate exposure to residues of 2,4-D.
E. Aggregate Risks and Determination of Safety for Infants and Children
1. Safety factor for infants and children-- i. In general. In
assessing the potential for additional sensitivity of infants and
children to residues of 2,4-D, EPA considered data from developmental
toxicity studies in the rat and rabbit and a 2-generation reproduction
study in the rat. The developmental toxicity studies are designed to
evaluate adverse effects on the developing organism resulting from
maternal pesticide exposure gestation. Reproduction studies provide
information relating to effects from exposure to the pesticide on the
reproductive capability of mating animals and data on systemic
toxicity.
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-and post-natal toxicity and the
completeness of the database 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 margin of exposure (MOE) analysis or through using
uncertainty (safety) factors in calculating a dose level that poses no
appreciable risk to humans. EPA believes that reliable data support
using the standard uncertainty factor (usually 100 for combined inter-
and intra-species variability) and not the additional tenfold MOE/
uncertainty factor when EPA has a complete data base under existing
guidelines and when the severity of the effect in infants or children
or the potency or unusual toxic properties of a compound do not raise
concerns regarding the adequacy of the standard MOE/safety factor.
ii. Developmental toxicity studies. In a developmental toxicity
study in rats, the maternal (systemic) NOAEL was >75 mg/kg/day at the
highest dose tested (HDT). The developmental (fetal) NOAEL was 25 mg/
kg/day, based on delayed ossification at the developmental LOAEL of 75
mg/kg/day. In a developmental toxicity study in rabbits, the maternal
(systemic) NOAEL was 30 mg/kg/day, based on ataxia, decreased motor
activity, cold extremities, and decreased body weight gain at the LOAEL
OF 90 mg/kg/day. The developmental (fetal) NOAEL was 90 mg/kg/day
(HDT).
iii. Reproductive toxicity study. In the 2-generation reproductive
toxicity study in rats, the parental (systemic) NOAEL of 5 mg/kg/day
was based on degenerative effects in the kidneys of males and decreased
body weight gain in females at the LOAEL of 20 mg/kg/day. The
reproductive (pup) NOAEL was 5 mg/kg/day, based on decreased pup weight
at the LOAEL of 20 mg/kg/day. The reproductive effects occurred in the
presence of parental toxicity.
iv. Pre- and post-natal sensitivity. The toxicological data base
for evaluating pre- and post-natal toxicity for 2,4-D is complete with
respect to current data requirements. There are pre-natal toxicity
concerns for infants and children, based on the results of the rat
developmental toxicity study in which developmental toxicity occurred
in the absence of maternal toxicity. Based on the developmental and
reproductive toxicity studies discussed above, for 2,4-D there does
appear to be an extra sensitivity for pre-natal effects.
EPA decided that the FQPA factor of 10 should be reduced to 3 for
females 13+ and removed for all other population subgroups. The
recommendation was based on the presence of developmental effects in
the absence of maternal effects for 2,4 D in the rat developmental
study. There was no indication of increased susceptibility in a rabbit
developmental study or a multigeneration reproduction study in rats.
Currently, the acute dietary risk assessment is based on the NOAEL
results of the acute neurotoxicity study and applies to all population
subgroups with an MOE requirement of 100. However, due to the FQPA
concerns discussed above, females 13+ will require an MOE of 300 (100 x
3 for FQPA), in contrast to the other population subgroups which will
continue to require the usual MOE of 100 (FQPA does not apply). In
practical terms, the acute dietary risk assessment will be performed
for all population subgroups using the NOAEL from the acute
neurotoxicity study. However, only females 13+ will require an MOE of
300 and all other population subgroups will require an MOE of 100.
v. Conclusion. There is a complete toxicity database for 2,4-D and
exposure data is complete or is estimated based on data that reasonably
accounts for potential exposures.
2. Acute risk. The acute dietary MOE was calculated to be 214 for
infants (less than 1 year old), and 399 for females 13+ years (accounts
for both maternal and fetal exposure). These MOE calculations were
based on the acute neurotoxicity NOAEL of 67 mg/kg/day. This risk
assessment assumed 100% crop-treated with anticipated or tolerance-
level residues on all treated crops consumed, resulting in a
significant over estimation of dietary exposure. The large acute
dietary MOE calculated for females 13+ years and infants (less than 1
year old) provides assurance that there is a reasonable certainty of no
harm for both females 13+ years and the pre-natal development of
infants or infants and children and post-natal exposure to 2,4-D.
The maximum estimated concentrations of 2,4-D in surface and ground
water are less than EPA's DWLOCs for 2,4-D as a contribution to acute
aggregate exposure. Therefore, EPA concludes with reasonable certainty
that residues of 2,4-D in
[[Page 11797]]
drinking water do not contribute significantly to the aggregate acute
human health risk at the present time considering the present uses and
uses proposed in this action.
EPA bases this determination on a comparison of estimated
concentrations of 2,4-D in surface waters and ground waters to levels
of comparison for 2,4-D in drinking water. The estimates of 2,4-D in
surface and ground waters are derived from water quality models that
use conservative assumptions regarding the pesticide transport from the
point of application to surface and ground water. Because EPA considers
the aggregate risk resulting from multiple exposure pathways associated
with a pesticide's uses, DWLOCs may vary as those uses change. If new
uses are added in the future, EPA will reassess the potential impacts
of 2,4-D on drinking water as a part of the aggregate acute risk
assessment process.
3. Chronic risk. Using the conservative exposure assumptions
described in this unit, EPA has concluded that aggregate exposure to
2,4-D from food will utilize from 11.4% of the RfD for nursing infants
less than one year old up to 49.2% of the RfD for non-nursing infants
less than one year old. EPA generally has no concern for exposures
below 100% of the RfD because the RfD represents the level at or below
which daily aggregate dietary exposure over a lifetime will not pose
appreciable risks to human health. Despite the potential for exposure
to 2,4-D in drinking water and from non-dietary, non-occupational
exposure, EPA does not expect the aggregate exposure to exceed 100% of
the RfD. EPA concludes that there is a reasonable certainty that no
harm will result to infants and children from aggregate exposure to
2,4-D residues.
4. Short- or intermediate-term risk. The short-term NOAEL for
dermal exposure is based on the maternal NOAEL of 30 mg/kg/day from the
oral developmental toxicity study in rabbits. After factoring in for
residential exposure, the calculated MOE or the short-term aggregate
risk of the most highly exposed subgroup (non-nursing infants (<1 year="" old))="" is="" 560,="" and="" does="" not="" exceed="" epa's="" level="" of="" concern.="" the="" intermediate-term="" noael="" for="" dermal="" exposure="" is="" based="" on="" the="" noael="" of="" 1.0="" mg/kg/day="" from="" the="" 90-day="" oral="" toxicity="" study="" in="" dogs.="" as="" homeowner="" use="" of="" 2,4-d="" is="" not="" expected="" to="" result="" in="" intermediate-term="" dermal="" exposure,="" only="" dietary="" and="" water="" exposures="" need="" be="" considered="" in="" this="" assessment.="" there="" is="" a="" potential="" for="" short-="" and="" intermediate-term="" exposure="" from="" drinking="" water.="" however,="" as="" estimated="" average="" concentrations="" of="" 2,4-d="" in="" surface="" and="" ground="" water="" are="" less="" than="" epa's="" levels="" of="" concern="" for="" drinking="" water="" as="" a="" contribution="" to="" chronic="" aggregate="" and="" acute="" aggregate="" exposures,="" contribution="" to="" short-="" and="" intermediate-term="" exposure="" should="" not="" exceed="" epa's="" levels="" of="" concern="" either.="" 5.="" determination="" of="" safety.="" based="" on="" these="" risk="" assessments,="" epa="" concludes="" that="" there="" is="" a="" reasonable="" certainty="" that="" no="" harm="" will="" result="" to="" infants="" and="" children="" from="" aggregate="" exposure="" to="" 2,4-d="" residues.="" iii.="" other="" considerations="" a.="" metabolism="" in="" plants="" and="" animals="" the="" nature="" of="" the="" residue="" in="" plants="" is="" adequately="" understood.="" the="" residue="" of="" concern="" is="" 2,4-d="" per="" se.="" the="" nature="" of="" the="" residue="" in="" animals="" is="" adequately="" understood="" based="" upon="" acceptable="" ruminant="" and="" poultry="" metabolism="" studies.="" the="" residues="" of="" concern="" in="" animals="" is="" 2,4-="" d,="" per="" se.="" b.="" analytical="" enforcement="" methodology="" adequate="" enforcement="" methodology="" is="" available="" (gas="" chromatography="" (gc)="" with="" electron="" capture="" detection="" (ecd),="" en-cas="" method="" enc-2/93.="" this="" gc/ecd="" method="" has="" undergone="" successful="" independent="" laboratory="" validation="" and="" is="" available="" to="" enforce="" the="" time-limited="" tolerance="" on="" soybean="" seed.="" c.="" magnitude="" of="" residues="" residues="" of="" 2,4-d="" are="" not="" expected="" to="" exceed="" 0.02="" ppm="" in/on="" soybean="" seed="" as="" a="" result="" of="" this="" use.="" secondary="" residues="" are="" expected="" in="" animal="" commodities="" as="" associated="" with="" this="" use.="" meat/milk/poultry/egg="" tolerances="" have="" been="" established="" as="" a="" result="" of="" other="" 2,4-d="" uses.="" d.="" international="" residue="" limits="" there="" are="" no="" codex,="" canadian="" or="" mexican="" residue="" limits="" established="" for="" 2,4-d="" on="" soybeans.="" e.="" rotational="" crop="" restrictions="" the="" confined="" rotational="" crop="" data="" indicate="" that="" no="" plant-back="" intervals="" following="" 2,4-d="" application="" are="" needed.="" iv.="" conclusion="" therefore,="" the="" tolerance="" is="" established="" for="" residues="" of="" 2,4-="" dichlorophenoxyacetic="" acid="" in="" soybeans="" at="" 0.02="" ppm.="" v.="" objections="" and="" hearing="" requests="" the="" new="" ffdca="" section="" 408(g)="" provides="" essentially="" the="" same="" process="" for="" persons="" to="" ``object''="" to="" a="" tolerance="" regulation="" as="" was="" provided="" in="" the="" old="" section="" 408="" and="" in="" section="" 409.="" however,="" the="" period="" for="" filing="" objections="" is="" 60="" days,="" rather="" than="" 30="" days.="" epa="" currently="" has="" procedural="" regulations="" which="" govern="" the="" submission="" of="" objections="" and="" hearing="" requests.="" these="" regulations="" will="" require="" some="" modification="" to="" reflect="" the="" new="" law.="" however,="" until="" those="" modifications="" can="" be="" made,="" epa="" will="" continue="" to="" use="" those="" procedural="" regulations="" with="" appropriate="" adjustments="" to="" reflect="" the="" new="" law.="" any="" person="" may,="" by="" may="" 10,="" 1999,="" file="" written="" objections="" to="" any="" aspect="" of="" this="" regulation="" and="" may="" also="" request="" a="" hearing="" on="" those="" objections.="" objections="" and="" hearing="" requests="" must="" be="" filed="" with="" the="" hearing="" clerk,="" at="" the="" address="" given="" under="" ``addresses''="" section="" (40="" cfr="" 178.20).="" a="" copy="" of="" the="" objections="" and/or="" hearing="" requests="" filed="" with="" the="" hearing="" clerk="" should="" be="" submitted="" to="" the="" opp="" docket="" for="" this="" rulemaking.="" the="" objections="" submitted="" must="" specify="" the="" provisions="" of="" the="" regulation="" deemed="" objectionable="" and="" the="" grounds="" for="" the="" objections="" (40="" cfr="" 178.25).="" each="" objection="" must="" be="" accompanied="" by="" the="" fee="" prescribed="" by="" 40="" cfr="" 180.33(i).="" 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="" tolerance="" objection="" fee="" waivers,="" contact="" james="" tompkins,="" registration="" division="" (7505c),="" office="" of="" pesticide="" programs,="" environmental="" protection="" agency,="" 401="" m="" st.,="" sw.,="" washington,="" dc="" 20460.="" office="" location,="" telephone="" number,="" and="" e-mail="" address:="" rm.="" 239,="" cm="" #2,="" 1921="" jefferson="" davis="" hwy.,="" arlington,="" va,="" (703)="" 305-5697,="">tompkins.jim@epa.gov. Requests for waiver of tolerance
objection fees should be sent to James Hollins, Information Resources
and Services Division (7502C), Office of Pesticide Programs,
Environmental Protection Agency, 401 M St., SW., Washington, DC 20460.
If a hearing is requested, the objections must include a statement
of the factual issues on which a hearing is requested, the requestor's
contentions on such issues, and a summary of any evidence relied upon
by the requestor (40 CFR 178.27). A request for a hearing will be
granted if the Administrator determines that the material submitted
shows the following: There is 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 in the
manner sought by the requestor would be adequate to justify
[[Page 11798]]
the action requested (40 CFR 178.32). 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.
VI. Public Record and Electronic Submissions
EPA has established a record for this regulation under docket
control number [OPP-300800] (including any comments and data submitted
electronically). A public version of this record, including printed,
paper versions of electronic comments, which does not include any
information claimed as CBI, is available for inspection from 8:30 a.m.
to 4 p.m., Monday through Friday, excluding legal holidays. The public
record is located in Rm. 119 of the Public Information and Records
Integrity Branch, Information Resources and Services Division (7502C),
Office of Pesticide Programs, Environmental Protection Agency, CM #2,
1921 Jefferson Davis Hwy., Arlington, VA.
Objections and hearing requests may be sent by e-mail directly to
EPA at:
opp-docket@epa.gov.
E-mailed objections and hearing requests must be submitted as an
ASCII file avoiding the use of special characters and any form of
encryption.
The official record for this regulation, as well as the public
version, as described in this unit will be kept in paper form.
Accordingly, EPA will transfer any copies of objections and hearing
requests received electronically into printed, paper form as they are
received and will place the paper copies in the official record which
will also include all comments submitted directly in writing. The
official record is the paper record maintained at the Virginia address
in ``ADDRESSES'' at the beginning of this document.
VII. Regulatory Assessment Requirements
A. Certain Acts and Executive Orders
This final rule establishes a tolerance under section 408(d) of the
FFDCA in response to a petition submitted to the Agency. The Office of
Management and Budget (OMB) has exempted these types of actions from
review under Executive Order 12866, entitled Regulatory Planning and
Review (58 FR 51735, October 4, 1993). 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) (Pub. L. 104-4). Nor does
it require any 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 in accordance with Executive Order
13045, entitled Protection of Children from Environmental Health Risks
and Safety Risks (62 FR 19885, April 23, 1997).
In addition, since tolerances and exemptions that are established
on the basis of a petition under FFDCA section 408(d), such as the
tolerance/exemption 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. Nevertheless, the Agency
previously assessed whether establishing tolerances, exemptions from
tolerances, raising tolerance levels or expanding exemptions might
adversely impact small entities and concluded, as a generic matter,
that there is no adverse economic impact. The factual basis for the
Agency's generic certification for tolerance actions published on May
4, 1981 (46 FR 24950), and was provided to the Chief Counsel for
Advocacy of the Small Business Administration.
B. Executive Order 12875
Under Executive Order 12875, entitled Enhancing the
Intergovernmental Partnership (58 FR 58093, October 28, 1993), EPA may
not issue a regulation that is not required by statute and that creates
a mandate upon a State, local or tribal government, unless the Federal
government provides the funds necessary to pay the direct compliance
costs incurred by those governments. If the mandate is unfunded, EPA
must provide to OMB a description of the extent of EPA's prior
consultation with representatives of affected State, local, and tribal
governments, the nature of their concerns, copies of any written
communications from the governments, and a statement supporting the
need to issue the regulation. In addition, Executive Order 12875
requires EPA to develop an effective process permitting elected
officials and other representatives of State, local, and tribal
governments ``to provide meaningful and timely input in the development
of regulatory proposals containing significant unfunded mandates.''
Today's rule does not create an unfunded Federal mandate on State,
local, or tribal governments. The rule does not impose any enforceable
duties on these entities. Accordingly, the requirements of section 1(a)
of Executive Order 12875 do not apply to this rule.
C. Executive Order 13084
Under Executive Order 13084, entitled Consultation and Coordination
with Indian Tribal Governments (63 FR 27655, May 19, 1998), EPA may not
issue a regulation that is not required by statute, that significantly
or uniquely affects the communities of Indian tribal governments, and
that imposes substantial direct compliance costs on those communities,
unless the Federal government provides the funds necessary to pay the
direct compliance costs incurred by the tribal governments. If the
mandate is unfunded, EPA must provide OMB, in a separately identified
section of the preamble to the rule, a description of the extent of
EPA's prior consultation with representatives of affected tribal
governments, a summary of the nature of their concerns, and a statement
supporting the need to issue the regulation. In addition, Executive
Order 13084 requires EPA to develop an effective process permitting
elected officials and other representatives of Indian tribal
governments ``to provide meaningful and timely input in the development
of regulatory policies on matters that significantly or uniquely affect
their communities.''
Today's rule does not significantly or uniquely affect the
communities of Indian tribal governments. This action does not involve
or impose any requirements that affect Indian tribes. Accordingly, the
requirements of section 3(b) of Executive Order 13084 do not apply to
this rule.
VIII. 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 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
[[Page 11799]]
the Comptroller General of the United States prior to publication of
the rule in the Federal Register. This rule is not a ``major rule'' as
defined by 5 U.S.C. 804(2).
List of Subjects in 40 CFR Part 180
Environmental protection, Administrative practice and procedure,
Agricultural commodities, Pesticides and pests, Reporting and
recordkeeping requirements.
Dated: March 1, 1999.
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. 346a and 371.
2. In Sec. 180.142, by revising paragraph (a)(11) to read as
follows:
Sec. 180.142 2,4-D; tolerances for residues.
(a) General . * * *
(11) A tolerance that expires on December 31, 2001 is established
for residues of the herbicide 2,4-D (2,4-dichlorophenoxyacetic acid)
resulting from the preplant use of 2,4-D ester or amine in or on the
food commodity as follows:
------------------------------------------------------------------------
Commodity Parts per million
------------------------------------------------------------------------
soybean, seed............................. 0.02
------------------------------------------------------------------------
* * * * *
[FR Doc. 99-5961 Filed 3-9-99; 8:45 am]
BILLING CODE 6560-50-F
