PMEP Home Page --> Pesticide Active Ingredient Information --> Herbicides, Growth Regulators and Desiccant --> dalapon to ethylene --> ethalfluralin (Curbit, Sonalan) --> ethalfluralin (Curbit, Sonalan) Pesticide Tolerances for Emergency Exemptions 11/97

ethalfluralin (Curbit, Sonalan) Pesticide Tolerances for Emergency Exemptions 11/97

 

[Federal Register: December 17, 1997 (Volume 62, Number 242)]
[Rules and Regulations]               
[Page 66008-66014]
>From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr17de97-10]

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

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[OPP-300585; FRL 5756-4]
RIN 2070-AB78

 
Ethalfluralin; Pesticide Tolerances for Emergency Exemptions

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final Rule.

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

SUMMARY: This regulation establishes a time-limited tolerance for 
residues of ethalfluralin in or on canola seed. This action is in 
response to EPA allowing issuance of crisis emergency exemptions under 
section 18 of the Federal Insecticide, Fungicide, and Rodenticide Act 
authorizing use of the pesticide on canola in Montana and North Dakota. 
This regulation establishes a maximum permissible level for residues of 
ethalfluralin in this food commodity 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 tolerance will expire and is 
revoked on October 31, 1998.

DATES: This regulation is effective December 17, 1997. Objections and 
requests for hearings must be received by EPA on or before February 17, 
1998.

ADDRESSES: Written objections and hearing requests, identified by the 
docket control number, [OPP-300585], 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-300585], 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. 1132, CM #2, 
1921 Jefferson Davis Hwy., Arlington, VA.
    A copy of objections and hearing requests filed with the Hearing 
Clerk may also be submitted electronically by sending electronic mail 
(e-mail) to: opp-docket@epamail.epa.gov. 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 
or ASCII file format. All copies of objections and hearing requests in 
electronic form must be identified by the docket control number [OPP-
300585]. 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: 
beard.andrea@epamail.epa.gov.

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 
residues of the herbicide ethalfluralin, in or on canola seed at 0.05 
part per million (ppm). This tolerance will expire and is revoked on 
October 31, 1998. EPA will publish a document in the Federal Register 
to remove the revoked tolerance 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

[[Page 66009]]

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 Ethalfluralin on Canola and FFDCA 
Tolerances

    The Applicants state that as canola acreage has grown, wild 
buckwheat has become an increasingly significant weed pest, and that 
the only available herbicide, trifluralin, does not provided adequate 
control of this weed. Thus, the Applicants found it necessary to issue 
crisis exemptions for this use of ethalfluralin, to avoid significant 
economic loss. EPA has authorized under FIFRA section 18 (the crisis 
provisions) the use of ethalfluralin on canola for control of wild 
buckwheat in Montana and North Dakota.
    As part of its assessment of this emergency exemption, EPA assessed 
the potential risks presented by residues of ethalfluralin in or on 
canola seed. In doing so, EPA considered the new safety standard in 
FFDCA section 408(b)(2), and EPA decided that the necessary tolerance 
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 this tolerance without notice and opportunity 
for public comment under section 408(e), as provided in section 
408(l)(6). Although this tolerance will expire and is revoked on 
October 31, 1998, under FFDCA section 408(l)(5), residues of the 
pesticide not in excess of the amounts specified in the tolerance 
remaining in or on canola seed after that date will not be unlawful, 
provided the pesticide is applied in a manner that was lawful under 
FIFRA. EPA will take action to revoke this tolerance earlier if any 
experience with, scientific data on, or other relevant information on 
this pesticide indicate that the residues are not safe.
    Because this tolerance is being approved under emergency conditions 
EPA has not made any decisions about whether ethalfluralin meets EPA's 
registration requirements for use on canola or whether a permanent 
tolerance for this use would be appropriate. Under these circumstances, 
EPA does not believe that this tolerance serves as a basis for 
registration of ethalfluralin by a State for special local needs under 
FIFRA section 24(c). Nor does this tolerance serve as the basis for any 
State other than Montana or North Dakota 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 ethalfluralin, 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

[[Page 66010]]

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 3 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 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 subgroup non-nursing 
infants, < 1 year old was 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 
ethalfluralin and to make a determination on aggregate exposure, 
consistent with section 408(b)(2), for a time-limited tolerance for 
residues of ethalfluralin on canola seed at 0.05 ppm. EPA's assessment 
of the dietary exposures and risks associated with establishing the 
tolerance follows.

A. Toxicological Profile

    EPA has evaluated the available toxicity data and considered its 
validity, completeness, and reliability as well as the relationship of 
the results of the studies to human risk. EPA has also considered 
available information concerning the variability of the sensitivities 
of major identifiable subgroups of consumers, including infants and 
children. The nature of the toxic effects caused by ethalfluralin are 
discussed below.
    1. Acute toxicity. For acute dietary risk assessment, EPA 
scientists have determined that the developmental NOEL of 75 mg/kg/day, 
from the rabbit developmental study should be used. The LOEL of 150 mg/
kg/day is based on increased number of resorptions and increased 
sternal and cranial variations. Since the effect of concern is 
reproductive in nature, the acute risk assessment will evaluate acute 
dietary risk to the population subgroup of concern, females 13 + years 
old.
     2. Short - and intermediate - term toxicity. No short- or 
intermediate-term toxicity endpoints have been identified for 
ethalfluralin, and OPP scientists determined that this assessment is 
not necessary.
    3. Chronic toxicity. EPA has established the RfD for ethalfluralin 
at 0.04 milligrams/kilogram/day (mg/kg/day). This RfD is based on a 1-
year feeding study in dogs with a NOEL of 4.0 mg/kg/day, and an 
uncertainty factor of 100. The LOEL of 20 mg/kg/day was based upon 
altered red cell morphology and urinary bilirubin.
    4. Carcinogenicity. Based on mammary gland fibroadenomas and 
combined mammary gland adenomas and/or fibroadenomas in female rats, 
ethalfluralin has been classified in Group C possible human carcinogen, 
according to EPA's Cancer Assessment Guidelines. The OPP Cancer Peer 
Review Committee recommended using the Q* approach for risk assessment, 
and the Q* of 8.9  x  10-2 has been calculated.

B. Exposures and Risks

    1. From food and feed uses. Tolerances have been established (40 
CFR 180.416) for the residues of ethalfluralin, in or on the following 
raw agricultural commodities: dry beans and peas, cucurbit vegetables, 
peanuts, soybeans, and sunflower seeds; and in animal commodities fat, 
meat, and meat byproducts of cattle, goats, hogs, horses, poultry, and 
sheep; and milk and eggs. According to the Ethalfluralin Reregistration 
Eligibility Document (RED), published March 1995, EPA is requiring 
revocation of all animal commodity tolerances, as they are not needed 
there is no expectation of finite residues. In the following risk 
assessments, the animal commodity tolerances are included, and then 
subsequently excluded from the refined cancer risk assessment. Risk 
assessments were conducted by EPA to

[[Page 66011]]

assess dietary exposures and risks from ethalfluralin 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. The acute risk assessment used 
tolerance-level residues for all commodities having ethalfluralin 
tolerances. For the population subgroup of concern, females 13 + years 
old, the Margin of Exposure (MOE) for the high-end consumer was 
calculated to be 25,000 (an MOE of  100 represents a 
negligible risk. Canola seed is processed into canola oil, a commodity 
which is not listed in OPP's dietary risk exposure system (DRES), so a 
standard DRES risk analysis including it cannot be conducted. However, 
canola oil is a very low consumption human food item 0.01% of the RfD, 
see below, and would be expected to contribute only a minor incremental 
increase to the acute dietary exposure. Additionally, the estimate 
given above should be considered extremely conservative, and if it were 
refined, using a Monte Carlo technique and incorporating anticipated 
residues and percent of crop treated figures, the MOEs would likely be 
much higher.
    ii. Chronic exposure and risk. The chronic dietary (food only) risk 
assessment for ethalfluralin was conducted using anticipated residue 
values and percent of crop treated information for some of the crops. 
Based on this, EPA has concluded that dietary exposure to ethalfluralin 
will utilize 2% of the RfD for the Overall US Population 0.01% of this 
attributed to canola oil. The major identifiable subgroup with the 
highest exposure is non-nursing infants < 1 year old, at 9% 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 ethalfluralin in drinking 
water. EPA does not expect the aggregate exposure to exceed 100% of the 
RfD.
    2. From drinking water. According to available data, ethalfluralin 
is moderately persistent and relatively immobile in soil, and is not 
expected to be a groundwater contaminant. Ethalfluralin does appear to 
have some potential to reach surface waters on eroded soil particles, 
but in surface waters, ethalfluralin would be expected to photodegrade 
rapidly. According to EPA's Pesticides in Ground Water Database, a 
total of 188 wells in Texas were monitored for ethalfluralin residues 
in 1987-88, and no detectable residues were reported. There are no 
Maximum Contaminant Levels or Health Advisory Levels established for 
ethalfluralin in drinking water.
    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 (RfDs 
or acute dietary NOELs) 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 ethalfluralin 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 ethalfluralin 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. Ethalfluralin is not currently 
registered for use on any residential non-food sites, and thus, it is 
not expected that non-occupational, non-dietary exposures will occur.
    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 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.
    Although ethalfluralin is a member of the nitroaniline class of 
herbicides, EPA does not have, at this time, available data to 
determine whether ethalfluralin 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, 
ethalfluralin 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 ethalfluralin has a common mechanism of 
toxicity with other substances.

C. Aggregate Risks and Determination of Safety for U.S. Population

    1. Acute risk. For the population subgroup of concern, females 13 + 
years old, the calculated MOE value for dietary exposure from food only 
is

[[Page 66012]]

25,000. Although there is potential for exposure to ethalfluralin in 
drinking water, EPA does not expect that this would result in an 
aggregate MOE food plus water that would exceed the level of concern 
MOE < 100 for acute dietary exposure. Therefore, EPA concludes that 
there is reasonable certainty that no harm will result from aggregate 
acute exposure to ethalfluralin.
    2. Chronic risk. Using the ARC exposure assumptions described 
above, EPA has concluded that aggregate exposure to ethalfluralin from 
food will utilize 2% of the RfD for the U.S. population. The major 
identifiable subgroup with the highest aggregate exposure is non-
nursing infants < 1 year old, at 9% of the RfD, 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 ethalfluralin 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 chronic exposure to ethalfluralin residues.

 D. Aggregate Cancer Risk for U.S. Population

    Based on the Q* of 0.089 (mg/kg/day)-1, and the 
anticipated residue contribution, the upper bound cancer risk estimate 
for the U.S. population is 6.2  x  10-5, contributed through 
all the published tolerances for ethalfluralin. However, as stated 
above, EPA is requiring revocation of the ethalfluralin tolerances for 
meat, milk, poultry, and eggs, due to the presumption that there are 
undetectable residues in these food items. When the cancer risk is 
calculated excluding these animal commodity tolerances, the resulting 
upper bound risk is 5.7  x  10-7, which is considered a 
negligible risk. This cancer risk analysis does not include canola oil, 
which is not covered by the DRES analysis. However, the consumption of 
canola oil has been calculated to comprise only 0.01% of the RfD, and 
thus, in the best scientific judgment of EPA, would not contribute 
appreciably to the dietary cancer risk from food uses of ethalfluralin.

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 ethalfluralin, EPA considered data from 
developmental toxicity studies in the rat and rabbit and a 3-generation 
reproduction study in the rat, and a 7-month multigeneration study in 
rats. 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 10-
fold 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 100-fold safely factor 
usually 100 for combined inter- and intra-species variability and not 
the additional 10-fold safety 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 
safety factor.
    ii. Developmental toxicity studies. In the developmental toxicity 
study in rats, the maternal systemic NOEL was 50 mg/kg/day, based on 
decreased body weight gain and dark urine at the LOEL of 250 mg/kg/day. 
The fetal developmental NOEL was 1000 mg/kg/day, at the highest dose 
tested (no effects observed to the fetuses).
    In the developmental toxicity study in rabbits, the maternal 
systemic NOEL was 75 mg/kg/day, based on abortions and decreased food 
consumption at the LOEL of 150 mg/kg/day. The fetal developmental NOEL 
was also 75 mg/kg/day, based on a slightly increased number of 
resorptions, abnormal cranial development, and increased sternal 
variants, at the LOEL of 150 mg/kg/day.
    iii. Reproductive toxicity study. In a 3-generation reproductive 
toxicity study in rats, the parental systemic NOEL was 12.5 mg/kg/day, 
based on decreased mean body weight gains in males in all generations, 
at the LOEL of 37.5 mg/kg/day. The pup reproductive NOEL was 37.5 mg/
kg/day, the highest dose tested no effects seen on the pups.
    In a 7-month multigeneration study in rats, the parental NOEL of 20 
mg/kg/day was based on increased liver weights at the LOEL of 61 mg/kg/
day. The pup reproductive NOEL was  61 mg/kg/day, the 
highest dose tested no effects seen on the pups.
    iv. Pre- and post-natal sensitivity. The toxicological data base 
for evaluating pre- and post-natal effects is complete for 
ethalfluralin. Based on the results of the developmental and 
reproduction studies outlined above, there are no pre- or post-natal 
toxicity concerns for infants and children, from exposure to 
ethalfluralin.
    v. Conclusion. Since no pre-or post-natal concerns have been 
identified for ethalfluralin, EPA scientists conclude that reliable 
data support use of the standard 100-fold uncertainty factor, and an 
additional uncertainty factor is not needed to protect infants and 
children.
    2. Acute risk. For the population subgroup of concern, females 13 + 
years old, the MOE for ethalfluralin dietary (food only) exposure is 
25,000; this accounts for both maternal and fetal exposure. Although 
there is potential for exposure to ethalfluralin in drinking water, EPA 
does not expect that this would result in an aggregate MOE (food plus 
water) that would exceed the level of concern MOE < 100 for acute 
dietary exposure. Therefore, EPA concludes that there is reasonable 
certainty that no harm will result, for both Females 13+ Years Old, and 
for the pre-natal development of infants, from aggregate acute exposure 
to ethalfluralin.
    3. Chronic risk. Using the conservative exposure assumptions 
described above, EPA has concluded that aggregate exposure to 
ethalfluralin from food will utilize 9% of the RfD for the highest 
exposed subgroup of infants and children, non-nursing infants, < 1 year 
old. EPA generally has no concern for exposures below 100% of the RfD 
because the RfD represents the level at or below which daily aggregate 
dietary exposure over a lifetime will not pose appreciable risks to 
human health. Despite the potential for exposure to ethalfluralin 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 chronic exposure to 
ethalfluralin residues.

[[Page 66013]]

V. Other Considerations

A. Metabolism In Plants and Animals

    The nature of the residue of ethalfluralin in plants and animals is 
adequately understood; the residue of concern is ethalfluralin per se, 
as specified in 40 CFR 180.416.

B. Analytical Enforcement Methodology

    Adequate enforcement methods gas-liquid chromatography with 
electron capture detection are available to enforce the tolerance, in 
both plant and animal tissues, and are listed in the Pesticide 
Analytical Manual, Volume II PAM-II.

C. Magnitude of Residues

    Residues of ethalfluralin are not expected to exceed 0.05 ppm in/on 
canola seed as a result of this section 18 use. Residues are not 
expected to concentrate in the processed commodities meal, refined oil 
of canola, and no tolerances are required for these commodities.

D. International Residue Limits

    There are no Codex, Canadian, or Mexican maximum residue limits 
established for ethalfluralin.

E. Rotational Crop Restrictions

    There are no plantback restrictions needed, and tolerances for 
rotational crop commodities need not be established.

VI. Conclusion

    Therefore, the tolerance is established for residues of 
ethalfluralin in canola seed at 0.05 ppm.

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 February 17, 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 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 Docket

    EPA has established a record for this rulemaking under docket 
control number [OPP--300585] (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 1132 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 Highway, Arlington, VA.
    Electronic comments may be sent directly to EPA at:
    opp-docket@epamail.epa.gov.


    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

    This final rule establishes [a tolerance] under FFDCA section 
408(l)(6). 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.
    In addition, since these tolerances and exemptions that are 
established under FFDCA section 408 (l)(6), such as the tolerance 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

[[Page 66014]]

generic certification for tolerance actions published on May 4, 1981 
(46 FR 24950), and was provided to the Chief Counsel for Advocacy of 
the Small Business Administration.

X. Submission to Congress and the General Accounting Office

    Under 5 U.S.C. 801(a)(1)(A), as added by the Small Business 
Regulatory Enforcement Fairness Act of 1996, the Agency has submitted 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 General Accounting Office prior to publication of this rule in 
today's Federal Register. This 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: November 25, 1997.

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

    Therefore, 40 CFR chapter I is amended as follows:

PART 180 -- [AMENDED]

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

    Authority: 21 U.S.C. 346a and 371.


    2. Section 180.416, is amended as follows:
    i. By designating the existing text as paragraph (a) and adding a 
heading.
    ii. By adding a new paragraph (b).
    iii. By adding and reserving new paragraphs (c) and (d) with 
headings to read as follows.


Sec. 180.416 Ethalfluralin; tolerances for residues.

    (a) General. * * *
    (b) Section 18 emergency exemptions. Time-limited tolerances are 
established for the residues of the herbicide ethalfluralin, in 
connection with use of the pesticide under section 18 emergency 
exemptions granted by EPA. The tolerances will expire on the dates 
specified in the following table.

                                                                        
------------------------------------------------------------------------
                                                          Expiration/   
            Commodity              Parts per million    revocation date 
------------------------------------------------------------------------
Canola, seed....................  0.05                10/31/98          
                                                                        
------------------------------------------------------------------------

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

[FR Doc. 97-32933 Filed 12-16-97; 8:45 am]
BILLING CODE 6560-50-F

/PRE>