[Federal Register Volume 63, Number 176 (Friday, September 11, 1998)]
[Rules and Regulations]
[Pages 48586-48594]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-24471]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
[OPP-300685; FRL-6017-9]
RIN 2070-AB78
Metolachlor; Pesticide Tolerances for Emergency Exemptions
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
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SUMMARY: This regulation establishes a time-limited tolerance for
combined residues of metolachlor and its metabolites determined as the
derivatives, 2-[(2-ethyl-6- methylphenyl)amino]-1-propanol and 4-(2-
ethyl-6-methylphenyl)-2-hydroxy-5-methyl-3- morpholinone, each
expressed as the parent compound in or on grass forage and grass hay.
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 grass grown for seed in Oregon.
This
[[Page 48587]]
regulation establishes maximum permissible levels for residues of
metolachlor in these feed commodities pursuant to section 408(l)(6) of
the Federal Food, Drug, and Cosmetic Act, as amended by the Food
Quality Protection Act of 1996. The tolerances will expire and are
revoked on December 31, 1999.
DATES: This regulation is effective September 11, 1998. Objections and
requests for hearings must be received by EPA on or before November 10,
1998.
ADDRESSES: Written objections and hearing requests, identified by the
docket control number, [OPP-300685], 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-300685], 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, 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: [email protected]. Copies of 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
file format or ASCII file format. All copies of objections and hearing
requests in electronic form must be identified by the docket control
number [OPP-300685]. No Confidential Business Information (CBI) should
be submitted through e-mail. Electronic copies of objections and
hearing requests on this rule may be filed online at many Federal
Depository Libraries.
FOR FURTHER INFORMATION CONTACT: By mail: Andrea Beard, 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: Crystal Mall #2, 1921
Jefferson Davis Hwy., Arlington, VA, (703) 308-9356, e-mail:
[email protected].
SUPPLEMENTARY INFORMATION: EPA, on its own initiative, pursuant to
section 408(e) and (l)(6) of the Federal Food, Drug, and Cosmetic Act
(FFDCA), 21 U.S.C. 346a(e) and (l)(6), is establishing a tolerance for
combined residues of the herbicide metolachlor and its metabolites
determined as the derivatives, 2-[(2-ethyl-6-methylphenyl)amino]-1-
propanol and 4-(2-ethyl-6-methylphenyl)-2-hydroxy-5-methyl-3-
morpholinone, each expressed as the parent compound, in or on grass
forage at 10 part per million (ppm), and grass hay at 0.2 ppm. These
tolerances will expire and are revoked on December 31, 1999. EPA will
publish a document in the Federal Register to remove the revoked
tolerances from the Code of Federal Regulations.
I. Background and Statutory Authority
The Food Quality Protection Act of 1996 (FQPA) (Pub. L. 104-170)
was signed into law August 3, 1996. FQPA amends both the Federal Food,
Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 301 et seq., and the Federal
Insecticide, Fungicide, and Rodenticide Act (FIFRA), 7 U.S.C. 136 et
seq . The FQPA amendments went into effect immediately. Among other
things, FQPA amends FFDCA to bring all EPA pesticide tolerance-setting
activities under a new section 408 with a new safety standard and new
procedures. These activities are described below and discussed in
greater detail in the final rule establishing the time-limited
tolerance associated with the emergency exemption for use of
propiconazole on sorghum (61 FR 58135, November 13, 1996)(FRL-5572-9).
New 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 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 FQPA. EPA has established regulations governing such
emergency exemptions in 40 CFR part 166.
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.
Because decisions on section 18-related tolerances must proceed
before EPA reaches closure on several policy issues relating to
interpretation and implementation of the FQPA, EPA does not intend for
its actions on such tolerance to set binding precedents for the
application of section 408 and the new safety standard to other
tolerances and exemptions.
II. Emergency Exemption for Metolachlor on Grass Grown for Seed and
FFDCA Tolerances
Because of cancellation of several herbicide uses in recent years,
a shift in weed populations and the development of resistance, plus
restrictions imposed on open field burning, grass growers are no longer
able to control weeds adequately with registered materials and cultural
methods. The Applicants claim that if weeds are not adequately
controlled, growers will incur significant economic losses due to
reduced yields, and from losses due to contaminated seed, and
replanting of fields that do not meet certification requirements. The
Applicant proposed use of metolachlor, in conjunction with several
other herbicides, to comprise a comprehensive management system to
solve the current weed control problems in grass seed production. EPA
has authorized under FIFRA section 18 the use of metolachlor on grass
grown for seed for control of weeds in Oregon. After having reviewed
the submission, EPA concurs that emergency conditions exist for this
State.
As part of its assessment of this emergency exemption, EPA assessed
the potential risks presented by residues of metolachlor in or on grass
hay and forage. In doing so, EPA considered the new safety standard in
FFDCA section
[[Page 48588]]
408(b)(2), and EPA decided that the necessary tolerances under FFDCA
section 408(l)(6) would be consistent with the new 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 under section 408(e), as provided in section 408(l)(6).
Although these tolerances will expire and are revoked on December 31,
1999, under FFDCA section 408(l)(5), residues of the pesticide not in
excess of the amounts specified in the tolerances remaining in or on
grass hay or forage 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 metolachlor
meets EPA's registration requirements for use on grass grown for seed
or whether permanent tolerances for this use would be appropriate.
Under these circumstances, EPA does not believe that these tolerances
serve as a basis for registration of metolachlor 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 Oregon to use this pesticide on this
crop under section 18 of FIFRA without following all provisions of
section 18 as identified in 40 CFR part 166. For additional information
regarding the emergency exemption for metolachlor, contact the Agency's
Registration Division at the address provided above.
III. Risk Assessment and Statutory Findings
EPA performs a number of analyses to determine the risks from
aggregate exposure to pesticide residues. First, EPA determines the
toxicity of pesticides based primarily on toxicological studies using
laboratory animals. These studies address many adverse health effects,
including (but not limited to) reproductive effects, developmental
toxicity, toxicity to the nervous system, and carcinogenicity. Second,
EPA examines exposure to the pesticide through the diet (e.g., food and
drinking water) and through exposures that occur as a result of
pesticide use in residential settings.
A. Toxicity
1. Threshold and non-threshold effects. For many animal studies, a
dose response relationship can be determined, which provides a dose
that causes adverse effects (threshold effects) and doses causing no
observed effects (the ``no-observed effect level'' or ``NOEL'').
Once a study has been evaluated and the observed effects have been
determined to be threshold effects, EPA generally divides the NOEL from
the study with the lowest NOEL by an uncertainty factor (usually 100 or
more) to determine the Reference Dose (RfD). The RfD is a level at or
below which daily aggregate exposure over a lifetime will not pose
appreciable risks to human health. An uncertainty factor (sometimes
called a ``safety factor'') of 100 is commonly used since it is assumed
that people may be up to 10 times more sensitive to pesticides than the
test animals, and that one person or subgroup of the population (such
as infants and children) could be up to 10 times more sensitive to a
pesticide than another. In addition, EPA assesses the potential risks
to infants and children based on the weight of the evidence of the
toxicology studies and determines whether an additional uncertainty
factor is warranted. Thus, an aggregate daily exposure to a pesticide
residue at or below the RfD (expressed as 100 % or less of the RfD) is
generally considered acceptable by EPA. EPA generally uses the RfD to
evaluate the chronic risks posed by pesticide exposure. For shorter
term risks, EPA calculates a margin of exposure (MOE) by dividing the
estimated human exposure into the NOEL from the appropriate animal
study. Commonly, EPA finds MOEs lower than 100 to be unacceptable. This
100-fold MOE is based on the same rationale as the 100-fold uncertainty
factor.
Lifetime feeding studies in two species of laboratory animals are
conducted to screen pesticides for cancer effects. When evidence of
increased cancer is noted in these studies, the Agency conducts a
weight of the evidence review of all relevant toxicological data
including short-term and mutagenicity studies and structure activity
relationship. Once a pesticide has been classified as a potential human
carcinogen, different types of risk assessments (e.g., linear low dose
extrapolations or MOE calculation based on the appropriate NOEL) will
be carried out based on the nature of the carcinogenic response and the
Agency's knowledge of its mode of action.
2. Differences in toxic effect due to exposure duration. The
toxicological effects of a pesticide can vary with different exposure
durations. EPA considers the entire toxicity data base, and based on
the effects seen for different durations and routes of exposure,
determines which risk assessments should be done to assure that the
public is adequately protected from any pesticide exposure scenario.
Both short and long durations of exposure are always considered.
Typically, risk assessments include ``acute,'' ``short-term,''
``intermediate term,'' and ``chronic'' risks. These assessments are
defined by the Agency as follows.
Acute risk, by the Agency's definition, results from 1-day
consumption of food and water, and reflects toxicity which could be
expressed following a single oral exposure to the pesticide residues.
High end exposure to food and water residues are typically assumed.
Short-term risk results from exposure to the pesticide for a period
of 1-7 days, and therefore overlaps with the acute risk assessment.
Historically, this risk assessment was intended to address primarily
dermal and inhalation exposure which could result, for example, from
residential pesticide applications. However, since enaction of FQPA,
this assessment has been expanded to include both dietary and non-
dietary sources of exposure, and will typically consider exposure from
food, water, and residential uses when reliable data are available. In
this assessment, risks from average food and water exposure, and high-
end residential exposure, are aggregated. High-end exposures from all
three sources are not typically added because of the very low
probability of this occurring in most cases, and because the other
conservative assumptions built into the assessment assure adequate
protection of public health. However, for cases in which high-end
exposure can reasonably be expected from multiple sources (e.g.
frequent and widespread homeowner use in a specific geographical area),
multiple high-end risks will be aggregated and presented as part of the
comprehensive risk assessment/characterization. Since the toxicological
endpoint considered in this assessment reflects exposure over a period
of at least 7 days, an additional degree of conservatism is built into
the assessment; i.e., the risk assessment nominally covers 1-7 days
exposure, and the toxicological endpoint/NOEL is selected to be
adequate for at least 7 days of exposure. (Toxicity results at
[[Page 48589]]
lower levels when the dosing duration is increased.)
Intermediate-term risk results from exposure for 7 days to several
months. This assessment is handled in a manner similar to the short-
term risk assessment.
Chronic risk assessment describes risk which could result from
several months to a lifetime of exposure. For this assessment, risks
are aggregated considering average exposure from all sources for
representative population subgroups including infants and children.
B. Aggregate Exposure
In examining aggregate exposure, FFDCA section 408 requires that
EPA take into account available and reliable information concerning
exposure from the pesticide residue in the food in question, residues
in other foods for which there are tolerances, residues in groundwater
or surface water that is consumed as drinking water, and other non-
occupational exposures through pesticide use in gardens, lawns, or
buildings (residential and other indoor uses). Dietary exposure to
residues of a pesticide in a food commodity are estimated by
multiplying the average daily consumption of the food forms of that
commodity by the tolerance level or the anticipated pesticide residue
level. The Theoretical Maximum Residue Contribution (TMRC) is an
estimate of the level of residues consumed daily if each food item
contained pesticide residues equal to the tolerance. In evaluating food
exposures, EPA takes into account varying consumption patterns of major
identifiable subgroups of consumers, including infants and children.
The TMRC is a ``worst case'' estimate since it is based on the
assumptions that food contains pesticide residues at the tolerance
level and that 100% of the crop is treated by pesticides that have
established tolerances. If the TMRC exceeds the RfD or poses a lifetime
cancer risk that is greater than approximately one in a million, EPA
attempts to derive a more accurate exposure estimate for the pesticide
by evaluating additional types of information (anticipated residue data
and/or percent of crop treated data) which show, generally, that
pesticide residues in most foods when they are eaten are well below
established tolerances.
Percent of crop treated estimates are derived from federal and
private market survey data. Typically, a range of estimates are
supplied and the upper end of this range is assumed for the exposure
assessment. By using this upper end estimate of percent of crop
treated, the Agency is reasonably certain that exposure is not
understated for any significant subpopulation group. Further, regional
consumption information is taken into account through EPA's computer-
based model for evaluating the exposure of significant subpopulations
including several regional groups, to pesticide residues. For this
pesticide, the most highly exposed population subgroups (non-nursing
infants <1 year old, and children 1 to 6 years old) were not regionally
based.
IV. 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
metolachlor and to make a determination on aggregate exposure,
consistent with section 408(b)(2), for time-limited tolerances for
combined residues of metolachlor and its metabolites in/on grass forage
at 10 ppm, and grass hay at 0.2 ppm. EPA's assessment of the dietary
exposures and risks associated with establishing the tolerances
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 metolachlor are
discussed below.
1. Acute toxicity. EPA scientists have determined that available
data do not indicate that there is potential for adverse effects after
a single dietary exposure. Therefore, acute risk assessments were not
conducted.
2. Short - and intermediate - term toxicity. For intermediate-term
dermal risk assessment, the NOEL of 100 milligrams/kilogram/day ( mg/
kg/day) from the 21-day dermal toxicity study in rats is to be used. At
the lowest effect level (LEL) of 1,000 mg/kg/day, there were dose-
related increases in minor histopathological alterations of the skin,
in total bilirubin (females), in absolute and relative liver weights
(males), and in relative kidney weights (females). An inhalation
exposure intermediate-term hazard was not identified. The EPA has
determined that the available data do not indicate the potential for
adverse effects from short-term dermal or inhalation exposures.
3. Chronic toxicity. EPA has established the RfD for metolachlor at
0.10 mg/kg bodyweight/day (bwt/day). This RfD is based on the results
from the 1-year feeding study in dogs, with a NOEL of 9.7 mg/kg/day,
and an uncertainty factor of 100, based on decreased body weight gain
at the LOEL of 33 mg/kg/day.
4. Carcinogenicity. Under the EPA Guidelines for Carcinogen Risk
Assessment, metolachlor has been classified as a Group C Chemical
(possible human carcinogen), based on increased incidence of adenomas
and combined adenomas/carcinomas in female rats. The structural
relationship of metolachlor to acetochlor and alachlor was of concern
to the OPP Carcinogenicity Peer Review Committee (CPRC). However, in
light of new information on the relative metabolism of these chemicals,
and since there was no supportable mutagenicity concern, the CPRC
recommended the MOE approach for estimation of risk, using the NOEL of
15.7 mg/kg/day from the 2-year rat feeding study.
B. Exposures and Risks
1. From food and feed uses. Tolerances have been established (40
CFR 180.368) for the combined residues of metolachlor and its
metabolites, in or on a variety of raw agricultural commodities ranging
from 0.02 ppm in various animal commodities, to 30 ppm in peanut forage
and hay. Risk assessments were conducted by EPA to assess dietary
exposures and risks from metolachlor 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 one day or single exposure. EPA scientists have determined that
available data do not indicate that there is potential for adverse
effects after a single dietary exposure. Therefore, acute risk
assessment is not required.
ii. Chronic exposure and risk. In conducting this chronic dietary
(food only) risk assessment, OPP used percent of crop treated data for
selected crops, and assumed tolerance level residues in all commodities
having metolachlor tolerances. These assumptions result in an
overestimate of human dietary exposure, and thus this risk estimate
should be viewed as conservative; further refinement using anticipated
residue levels and additional percent crop treated values would result
in lower exposure estimates. Based on the given assumptions, EPA has
calculated
[[Page 48590]]
that dietary exposure to metolachlor will utilize 1.1 % of the RfD for
the overall U.S. population. The major identifiable subgroups with the
highest exposure are non-nursing infants <1 year old and children 1 to
6 years old, both at 2.3 % of the RfD. This is further discussed below
in the section on infants and children. EPA generally has no concern
for exposure 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 metolachlor in drinking water, EPA does not expect the
aggregate exposure to exceed 100% of the RfD. EPA concludes that there
is reasonable certainty that no harm will result from chronic aggregate
exposure to metolachlor residues.
2. From drinking water. Environmental fate studies indicate that
metolachlor appears to be moderately persistent and ranges from being
mobile to highly mobile in different soils. Data collected from around
the US provides evidence that metolachlor leaches into ground water,
occasionally at levels that exceed the Lifetime Health Advisory (HA)
level of 100 ppb. Metolachlor is not yet formally regulated under the
Safe Drinking Water Act; therefore, no enforcement Maximum Contaminant
Level (MCL) has been established for it. Metolachlor also has
relatively high health advisory levels (1-10 day HA level of 2,000 ppb
and lifetime HA level of 100 ppb). Based on available data, it appears
highly unlikely that maximum or short-term average metolachlor
concentrations will exceed the 1-10 day HA levels of 2,000 ppb, or that
annual average metolachlor concentrations will exceed the lifetime HA
of 100 ppb anywhere. Additionally, to mitigate risk, additional label
restrictions are being required under the Reregistration process,
designed to minimize ground and surface water contamination.
Because the Agency lacks sufficient water-related exposure data to
complete a comprehensive drinking water risk assessment for many
pesticides, EPA has commenced and nearly completed a process to
identify a reasonable yet conservative bounding figure for the
potential contribution of water-related exposure to the aggregate risk
posed by a pesticide. In developing the bounding figure, EPA estimated
residue levels in water for a number of specific pesticides using
various data sources. The Agency then applied the estimated residue
levels, in conjunction with appropriate toxicological endpoints (RfD's
or acute dietary NOEL's) and assumptions about body weight and
consumption, to calculate, for each pesticide, the increment of
aggregate risk contributed by consumption of contaminated water. While
EPA has not yet pinpointed the appropriate bounding figure for exposure
from contaminated water, the ranges the Agency is continuing to examine
are all below the level that would cause metolachlor to exceed the RfD
if the tolerance being considered in this document were granted. The
Agency has therefore concluded that the potential exposures associated
with metolachlor in water, even at the higher levels the Agency is
considering as a conservative upper bound, would not prevent the Agency
from determining that there is a reasonable certainty of no harm if the
tolerance is granted.
3. From non-dietary exposure. Metolachlor is currently registered
for use on a number of residential non-food sites including ornamental
plants and grasses, highway rights of way, and recreational areas. No
indoor uses are registered.
i. Acute exposure and risk. EPA generally will not include
residential or other non-dietary exposures as a component of the acute
exposure assessment. Theoretically, it is also possible that a
residential, or other non-dietary, exposure could be combined with the
acute total dietary exposure from food and water. However, the Agency
does not believe that aggregate multiple exposure to large amounts of
pesticide residues in the residential environment via multiple products
and routes for a one day exposure is a reasonably probable event. It is
highly unlikely that, in one day, an individual would have multiple
high-end exposures to the same pesticide by treating their lawn and
garden, treating their house via crack and crevice application,
swimming in a pool, and be maximally exposed by the food and water
consumed. Additionally, the concept of an acute exposure as a single
exposure does not allow for including post-application exposures, in
which residues decline over a period of days after application.
Therefore, the Agency believes that residential exposures are more
appropriately included in the short-term exposure scenario discussed
below.
ii. Short- and intermediate-term exposure and risk. There are
residential uses of metolachlor and EPA acknowledges that there may be
short and intermediate-term non-occupational exposure scenarios. The
EPA has identified a toxicity endpoint for intermediate-term
residential risks. However, no acceptable reliable exposure data to
assess the potential risks are available at this time. Based on the
high level of the intermediate-term toxicity endpoint (NOEL of 100 mg/
kg/day, and LOEL of 1,000 mg/kg/day), the Agency does not expect the
intermediate-term aggregate risk to exceed the level of concern. A
short-term non-dietary toxicity endpoint was not identified for
metolachlor.
iii. Chronic exposure and risk. The Agency has concluded that a
chronic residential exposure scenario does not exist for non-
occupational uses of metolachlor.
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.'' The Agency believes that ``available
information'' in this context might include not only toxicity,
chemistry, and exposure data, but also scientific policies and
methodologies for understanding common mechanisms of toxicity and
conducting cumulative risk assessments. For most pesticides, although
the Agency has some information in its files that may turn out to be
helpful in eventually determining whether a pesticide shares a common
mechanism of toxicity with any other substances, EPA does not at this
time have the methodologies to resolve the complex scientific issues
concerning common mechanism of toxicity in a meaningful way. EPA has
begun a pilot process to study this issue further through the
examination of particular classes of pesticides. The Agency hopes that
the results of this pilot process will increase the Agency's scientific
understanding of this question such that EPA will be able to develop
and apply scientific principles for better determining which chemicals
have a common mechanism of toxicity and evaluating the cumulative
effects of such chemicals. The Agency anticipates, however, that even
as its understanding of the science of common mechanisms increases,
decisions on specific classes of chemicals will be heavily dependent on
chemical specific data, much of which may not be presently available.
Although at present the Agency does not know how to apply the
information in its files concerning common mechanism issues to most
risk assessments, there are pesticides as to which the common mechanism
issues can be resolved. These pesticides include pesticides that are
toxicologically dissimilar to existing chemical substances (in which
case the
[[Page 48591]]
Agency can conclude that it is unlikely that a pesticide shares a
common mechanism of activity with other substances) and pesticides that
produce a common toxic metabolite (in which case common mechanism of
activity will be assumed).
EPA does not have, at this time, available data to determine
whether metolachlor 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,
metolachlor 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 metolachlor has a common mechanism of toxicity
with other substances.
C. Aggregate Risks and Determination of Safety for U.S. Population
1. Acute risk. The available data for metolachlor do not indicate
the potential for adverse effects from acute dietary exposures.
Therefore, an acute aggregate risk assessment was not conducted.
2. Chronic risk. Using the conservative exposure assumptions
described above, EPA has concluded that aggregate exposure to
metolachlor from food will utilize 1.1 % of the RfD for the U.S.
population. The major identifiable subgroup with the highest aggregate
exposure is non-nursing infants <1 year old, and children 1 to 6 years
old, both at 2.3 % of the RfD; this is further 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 metolachlor 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 from
aggregate exposure to metolachlor 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. Based on the low percentage of the RfD occupied
by the chronic dietary exposure (<3% for all population subgroups) and
the high level of the intermediate-term toxicity endpoint (NOEL and
LOEL of 100 and 1,000 mg/kg/day, respectively), in the best scientific
judgment of EPA, the intermediate-term aggregate risk will not exceed
the Agency's level of concern. Despite the potential for exposure to
metolachlor in drinking water, EPA does not expect the aggregate
exposure to exceed 100% of the RfD. Since a short-term toxicity
endpoint was not identified for metolachlor, a short-term aggregate
risk assessment was not conducted.
D. Aggregate Cancer Risk for U.S. Population
Based on the CPRC recommendation that the MOE approach be used to
assess cancer risk, a quantitative cancer risk assessment was not
performed. Based on the aggregate chronic dietary analysis (food only),
the calculated MOEs for the U.S. population and infants/children are
15,000 and 6,800, respectively. Other than dietary exposure, no chronic
exposure scenarios have been identified from registered uses of
metolachlor. The EPA believes that the potential additional exposure in
drinking water would not significantly lower the chronic dietary MOEs.
The EPA has not yet estabalished what an adequate MOE should be for
chemicals having a non-linear mechanism for carcinogenicity. At this
time, and for the purpose of this action only, the Agency concludes
that the MOEs given above are adequate to ensure that there is a
reasonable certainty that no harm to the U.S. population or to infants
and children, will result from aggregate exposure to residues of
metolachlor. When the Agency reaches a conclusion on the science policy
issue of adequate MOEs for non-linear carcinogens, it is possible that
the risk assessment for metolachlor may need to be revised.
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 metolachlor, EPA considered data from
developmental toxicity studies in the rat and rabbit and a two-
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 during 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 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 MOE
and 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 the rat developmental study,
the maternal NOEL was 300 mg/kg/day; mortality, increased salivation,
lacrimation, convulsions, reduced body weight gain, and reduced food
consumption were observed at the LEL of 1,000 mg/kg/day. The
developmental NOEL was also 300 mg/kg/day, with reduced mean fetal body
weight, reduced number of implantations, and a slight increase in
resorptions, seen at the LEL of 1,000 mg/kg/day. In the rabbit
developmental study, the maternal NOEL was 120 mg/kg/day, with
lacrimation, miosis, reduced food consumption, and decreased body
weight gain seen at the LEL of 360 mg/kg/day. No developmental effects
were observed at the levels tested, and therefore the developmental
NOEL was greater than 360 mg/kg/day (the highest dose tested (HDT)).
iii. Reproductive toxicity study. In the two-generation rat
reproductive study, the reproductive/developmental toxicity NOEL of 23
mg/kg/day was less than the parental (systemic) toxicity NOEL of >76
mg/kg/day (HDT). The reproductive/developmental NOEL was based on
decreased pup body weight during late lactation.
iv. Pre- and post-natal sensitivity. Based on current toxicological
data requirements, the database for metolachlor relative to pre- and
post-natal toxicity is complete. The developmental toxicity NOELs of
300 mg/kg/day ( in rats) and >360 mg/kg/day (HDT tested in rabbits)
demonstrate that there is not increased sensitivity to metolachlor by
the developing fetus (pre-natal) in the presence of maternal toxicity.
There was developmental toxicity in rats at 1,000 mg/kg/day (but
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not in rabbits). The developmental NOELs are more than 30- and 37-fold
higher in the rats and rabbits, respectively, than the NOEL of 9.7 mg/
kg/day from the 1-year feeding study in dogs, which is the basis of the
RfD. In the two-generation reproductive toxicity study in rats, the
reproductive/developmental toxicity NOEL of 23 mg/kg/day was less than
the parental (systemic) toxicity NOEL of >76 mg/kg/day. The
reproductive/developmental NOEL was based on decreased pup body weight
during late lactation and the NOEL occurred at a level which is below
the NOEL for parental toxicity (>76 mg/kg/day). This finding suggests
that pups are more sensitive to metolachlor than adult animals. For
purposes of this Section 18 only, an additional 3-fold uncertainty
factor was added to the RfD for infants and children.
v. Conclusion. The TMRC value for the most highly exposed infant
and children subgroups (non-nursing infants <1 year old, and children 1
to 6 years old) occupies 6.9% of the RfD for both groups (with the
additional 3-fold safety factor). This estimate should be viewed as
conservative, since it is based on percent of crop treated data for
selected crops and tolerance level residues for all commodities.
Refinement of the dietary risk assessment by using additional percent
crop treated and anticipated residue data would reduce dietary exposure
estimates. Therefore, this risk assessment is an over-estimate of
dietary risk.
2. Acute risk. The available data for metolachlor do not indicate
the potential for adverse effects from acute dietary exposures.
Therefore, no acute risk assessment was conducted.
3. Chronic risk. Using the conservative exposure assumptions
described above, EPA has concluded that aggregate exposure to
metolachlor from food ranges from 6.9 % for non-nursing infants <1 year
old, down to 1.8 % for nursing infants <1 year old (using an additional
three-fold safety factor). 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 metolachlor 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
metolachlor residues.
4. Short- or 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. A short-term non-dietary toxicity endpoint was
not identified for metolachlor. Using the conservative exposure
assumptions described above, EPA has concluded that the percent of the
RfD that will be utilized by aggregate exposure to residues of
metolachlor is 6.9 % (using an additional 3 fold safety factor) for
non-nursing infants <1 year old and children 1 to 6 years old (the most
highly exposed population subgroups). Based on the low percentage of
the RfD occupied by the chronic dietary exposure and the high level of
the intermediate-term toxicity endpoint (NOEL = 100 mg/kg/day and LOEL
= 1,000 mg/kg/day), in the best scientific judgment of EPA, the
intermediate-term aggregate risk will not exceed the Agency's level of
concern. Despite the potential for exposure to metolachlor in drinking
water, EPA does not expect the aggregate exposure to exceed 100% of the
RfD.
V. Other Considerations
A. Metabolism In Plants and Animals
The nature of the residue in plants and animals is adequately
understood. Tolerances for residues of metolachlor in or on food/feed
commodities are currently expressed in terms of the combined residues
(free and bound) of the herbicide metolachlor ([2-chloro-N-(2-ethyl-6-
methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide]) and its
metabolites, determined as the derivatives, 2-[(2-ethyl-6-
methylphenyl)amino]-1-propanol and 4-(2-ethyl-6-methylphenyl)-2-
hydroxy-5-methyl-3-morpholinone, each expressed as the parent compound
(40 CFR 180.368)] .
B. Analytical Enforcement Methodology
Adequate methods for purposes of data collection and enforcement of
tolerances for metolachlor residues are available. Methods for
determining the combined residues of metolachlor and its metabolites,
as the derivatives CGA-37913 and CGA-49751, are described in PAM, Vol.
II, as Method I (plants; Gas Chromatograpy (GC) with Nitrogen
Phosphorus Detection(NPD)) and Method II (animals; GC-Mass
Spectroscopy).
C. Magnitude of Residues
Residues of metolachlor are not expected to exceed 10 ppm in/on
forage and 0.2 ppm in/on the hay of grass grown for seed, as a result
of this section 18 use. Secondary residues in animal commodities are
not expected to exceed existing tolerances as a result of this section
18 use.
D. International Residue Limits
There are no established CODEX, Canadian, or Mexican residue limits
for metolachlor on grass commodities.
E. Rotational Crop Restrictions
Fields in which certified grass seed is grown are not normally
rotated to other crops; rotational crop restrictions are not required
for this use.
VI. Conclusion
Therefore, the tolerance is established for combined residues of
metolachlor and its metabolites, each expressed as the parent compound
in grass forage and grass hay at 10 ppm and 0.2 ppm, respectively.
VII. Objections and Hearing Requests
The new FFDCA section 408(g) provides essentially the same process
for persons to ``object'' to a tolerance regulation issued by EPA under
new section 408(e) and (l)(6) 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 November 10, 1998, 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 above (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). 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
[[Page 48593]]
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 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.
VIII. Public Record and Electronic Submissions
EPA has established a record for this rulemaking under docket
control number [OPP-300685] (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 Room 119 of the Public Information and Records
Integrity Branch, Information Resources and Services Division (7502C),
Office of Pesticide Programs, Environmental Protection Agency, Crystal
Mall #2, 1921 Jefferson Davis Hwy., Arlington, VA.
Electronic comments may be sent directly to EPA at:
[email protected].
Electronic comments must be submitted as an ASCII file avoiding the
use of special characters and any form of encryption.
The official record for this rulemaking, as well as the public
version, as described above 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 rulemaking record which
will also include all comments submitted directly in writing. The
official rulemaking record is the paper record maintained at the
Virginia address in ``ADDRESSES'' at the beginning of this document.
IX. Regulatory Assessment Requirements
A. Certain Acts and Executive Orders
This final rule establishes tolerances under FFDCA section 408(d)
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 prior consultation as specified by Executive Order
12875, entitled Enhancing the Intergovernmental Partnership (58 FR
58093, October 28, 1993), or 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).
B. Executive Order 12875
Under Executive Order 12875, entitled Enhancing Intergovernmental
Partnerships (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 the Office of Management and Budget (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 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.
In addition, since these tolerances and exemptions that are
established under FFDCA section 408 (l)(6), 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. Nevertheless, the Agency has 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
[[Page 48594]]
Chief Counsel for Advocacy of the Small Business Administration.
X. 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 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: August 14, 1998.
Arnold E. Layne,
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. 180.368, in paragraph (b), by alphabetically adding the
following commodities to the table to read as follows:
Sec. 180.368 Metolachlor; tolerances for residues.
* * * * *
(b) * * *
------------------------------------------------------------------------
Expiration/
Commodity Parts per million revocation date
------------------------------------------------------------------------
Grass forage.................... 10 12/31/99
Grass hay....................... 0.2 12/31/99
* * * * * * *
------------------------------------------------------------------------
* * * * *
[FR Doc. 98-24471 Filed 9-10-98; 8:45 am]
BILLING CODE 6560-50-F