[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

[[Page 48592]]

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