[Federal Register Volume 62, Number 153 (Friday, August 8, 1997)]
[Rules and Regulations]
[Pages 42678-42684]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-20844]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[OPP-300517; FRL-5731-7]
RIN 2070-AB78


Herbicide Safener HOE-107892; 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 the 
inert ingredient, herbicide safener HOE-107892 (mefenpyr-diethyl) and 
its 2,4-dichlorophenyl-pyrazoline metabolites HOE-094270 and HOE-113225 
in or on wheat grain and wheat straw. 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 herbicide safener on wheat grain and wheat straw in North Dakota 
and Montana. This regulation establishes a maximum permissible level 
for residues of the Herbicide safener HOE-107892 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 
tolerances will expire and are revoked on August 1, 1998.

DATES: This regulation is effective August 8, 1997. Objections and 
requests for hearings must be received by EPA on or before October 7, 
1997.
ADDRESSES: Written objections and hearing requests, identified by the 
docket control number, [OPP-300517], 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-300517], must also be submitted to: Public 
Information and Records Integrity Branch, Information Resources and 
Services Division (7506C), 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: <a href="/cdn-cgi/l/email-protection#660916164b0209050d0312260316070b070f0a4803160748010910"><span class="__cf_email__" data-cfemail="a3ccd3d38ec7ccc0c8c6d7e3c6d3c2cec2cacf8dc6d3c28dc4ccd5">[email protected]</span></a>. 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 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-300517]. 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: Pat Cimino, 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) 308-9357, e-mail: 
<a href="/cdn-cgi/l/email-protection#72111b1f1b1c1d5c021306321702131f131b1e5c1702135c151d04"><span class="__cf_email__" data-cfemail="d1b2b8bcb8bfbeffa1b0a591b4a1b0bcb0b8bdffb4a1b0ffb6bea7">[email protected]</span></a>.

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 tolerances for 
the inert ingredient herbicide safener HOE-107892 (mefenpyr-diethyl) 
and its 2,4-dichlorophenyl-pyrazoline metabolites HOE-094270 and HOE-
113225 in or on wheat grain and wheat straw at 0.01 and 0.05 ppm 
respectively. These tolerances will expire and are revoked on August 1, 
1998. 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.

[[Page 42679]]

II. Emergency Exemption for Herbicide Safener HOE-107892 (mefenpyr-
diethyl) on Wheat Grain and Wheat Straw and FFDCA Tolerances

    The North Dakota and Montana State Departments of Agriculture 
requested the use of PUMA 1EC Herbicide for control of green and yellow 
foxtail (pigeon grass) in durum wheat in North Dakota and Montana. The 
active ingredient in PUMA 1EC is fenoxaprop-ethyl which has tolerances 
established for uses on wheat. However, fenoxaprop-ethyl is phytotoxic 
to durum wheat without the addition of an inert ingredient safener. The 
herbicide safener HOE-107892 allows the active ingredient, fenoxaprop-
ethyl, to control yellow and green foxtail without harming the durum 
wheat. Although HOE-107892 (mefenpyr-diethyl) is an inert ingredient, 
tolerances for residues from its use on foods/feeds are required by the 
FFDCA. EPA has authorized under FIFRA section 18 the use of the 
Herbicide safener HOE-107892 on wheat grain and wheat straw for control 
of green and yellow foxtail (pigeon grass) in North Dakota and Montana. 
After having reviewed the submissions, EPA concurs that emergency 
conditions exist for these States.
    As part of its assessment of this emergency exemption, EPA assessed 
the potential risks presented by residues of the Herbicide safener HOE-
107892 in or on wheat grain and wheat straw. 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 August 1, 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 wheat grain and wheat straw 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 Herbicide safener HOE-
107892 meets EPA's registration requirements for use on wheat grain and 
wheat straw 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 Herbicide safener HOE-
107892 by a State for special local needs under FIFRA section 24(c). 
Nor do these tolerances serve as the basis for any States other than 
North Dakota and Montana 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 Herbicide safener HOE-107892, 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

[[Page 42680]]

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 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 children 1-6 
years 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 the 
Herbicide safener HOE-107892 and to make a determination on aggregate 
exposure, consistent with section 408(b)(2), for a time-limited 
tolerance for HOE-107892 and its 2,4-dichlorophenyl-pyrazoline 
metabolites HOE-094270 and HOE-113225 on wheat grain and wheat straw at 
0.01 and 0.05 ppm respectively. 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 Herbicide safener 
HOE-107892 are discussed below.
    1. Acute toxicity. The Agency recommended using the NOEL of 100 
milligrams per kilogram per day (mg/kg/day) based on abortions and 
fetal intrauterine deaths without morphological developmental effects, 
at the lowest effect level (LEL) of 250 mg/kg/day from the rabbit 
developmental study. This NOEL is used to evaluate the Margin of 
Exposure (MOE) from the acute dietary risk to pregnant women 13+ years 
or older.
     2. Short - and intermediate - term toxicity. No short- or 
intermediate-term non-dietary, non-occupational exposure scenario 
exists for HOE-107892 because no uses currently exist for the safener 
and only agricultural uses are requested for these section 18s.
    3. Chronic toxicity. For purposes of this section 18 request use 
only, EPA has established the RfD for Herbicide safener HOE-107892 at 
0.01 mg/kg/day. The temporary RfD is based on the chronic toxicity/
carcinogenicity study in mice with a NOEL of 3.0 mg/kg/day (20 ppm) and 
an uncertainty factor of 300 (due to the absence of full evaluation of 
the toxicology data base). At the LEL of 1.5 mg/kg/day (100 ppm), dose-
related hepatocellular hypertrophy was present in male mice.
    4. Carcinogenicity. The mouse and rat cancer studies with the 
safener have not been reviewed and classified by the Agency. Perusal of 
the cancer studies by the Agency indicates no identifiable cancer 
concern in the mouse study. However, a possible concern regarding the 
increased incidence of thyroid follicular cell adenomas and carcinomas 
combined at the highest dose tested of 5,000 ppm in the rat 
carcinogenicity study was identified. This study requires an in-depth 
review by the Agency. Until that time, it is not known if a cancer risk 
assessment is required or what method of quantification would be 
appropriate. Therefore, for purposes of these Section 18s, a cancer 
risk assessment will not be conducted.

[[Page 42681]]

B. Exposures and Risks

    1. From food and feed uses. No permanent tolerances have been 
established for the inert ingredient herbicide safener HOE-107892. 
There are no indoor or outdoor residential uses registered for the 
safener. Risk assessments were conducted by EPA to assess dietary 
exposures and risks from Herbicide safener HOE-107892 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 dietary exposure endpoints 
of concern for the herbicide safener HOE-107892 are abortions and fetal 
intrauterine deaths without morphological developmental effects, which 
were observed in the rabbit developmental study. The population 
subgroup of concern is pregnant females 13+ years old. Acute dietary 
exposure (food only) was calculated using the high end exposure value 
and TMRC (worst case) assumptions. Therefore, this risk assessment is 
considered conservative. Despite the potential for acute exposure to 
the herbicide safener HOE-107892 in drinking water, EPA does not expect 
the aggregate acute exposure to exceed the Agency's level of concern.
    ii. Chronic exposure and risk. In conducting exposure assessments 
for these section 18 requests, EPA used tolerance level residues and 
assumed that 100% of the crop would be treated with the pesticide (TMRC 
worst-case analysis assumptions) as described above.
    2. From drinking water. The Agency's Environmental Fate data base 
indicates that HOE-107892 is persistent in the environment and has 
little potential for soil mobility or leaching.
    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 Herbicide safener HOE-107892 
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 Herbicide safener HOE-107892 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. 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).
    EPA does not have, at this time, available data to determine 
whether Herbicide safener HOE-107892 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, 
Herbicide safener HOE-107892 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 Herbicide safener 
HOE-107892 has a common mechanism of toxicity with other substances.

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

    1. Acute risk. As discussed above, the acute dietary exposure 
endpoint of concern for HOE-107892 is abortions and fetal intrauterine 
deaths which were observed in the rabbit developmental toxicology 
study. For the U.S. populations subgroup of concern, females of 
childbearing age (13+ years old) , an MOE value of 10,000 was 
calculated using the high end human exposure value of 0.00006 mg/kg/
day. The Agency generally considers MOEs over 100 acceptable. This 
acute dietary (food only) risk assessment used tolerance level residues 
and assumed 100% crop-treated (TMRC worst-case analysis, described 
above). Despite the potential for risk from acute exposure to HOE-
107892 in drinking water, the Agency does not expect acute aggregate 
exposure to exceed its level of concern. EPA concludes that there is 
reasonable certainty that no harm will result from acute aggregate 
exposure to HOE-107892.
    2. Chronic risk. Using the conservative TMRC exposure assumptions 
described above, EPA has concluded that aggregate exposure to Herbicide 
safener HOE-107892 from food will utilize less than 0.01% of the RfD 
for the U.S. population and all population subgroups, including infants 
and children. EPA generally has no concern for exposures below 100% of 
the RfD because the RfD represents the

[[Page 42682]]

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 Herbicide safener HOE-107892 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 Herbicide safener HOE-107892 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.
    Because no short- or intermediate-term non-dietary, non-
occupational exposure scenario exists for HOE-107892, a short- or 
intermediate-term aggregate risk assessment is not required.

D. Aggregate Risks and Determination of Safety for Infants and Children

    1. Safety factor for infants and children--a. In general. In 
assessing the potential for additional sensitivity of infants and 
children to residues of Herbicide safener HOE-107892, 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 pesticide exposure during prenatal 
development to one or both parents. 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.
    b. Developmental toxicity studies. In the rat developmental 
toxicity study, the maternal (systemic) NOEL was 1,000 mg/kg/day 
(highest dose tested). The developmental (pup) NOEL was 1,000 mg/kg/day 
(highest dose tested).
    In the rabbit developmental toxicity study, the maternal (systemic) 
NOEL of 100 mg/kg/day, was based on decreased body weight gain and food 
consumption, and abortions in the does at the LOEL of 250 mg/kg/day. 
The developmental (pup) NOEL was 100 mg/kg/day, based on intrauterine 
deaths of fetuses without morphological developmental effects at 250 
mg/kg/day.
    c. Reproductive toxicity study. In the rat reproduction study, the 
parental (systemic) NOEL was 75 mg/kg/day, based on decreased food 
consumption, body weight, increased spleen weights and increased 
splenic hematopoiesis at the LOEL of 396 mg/kg/day. The reproductive/
developmental (pup) NOEL was 75 mg/kg/day, based on decreased body 
weight at the LEL of 396 mg/kg/day.
    d. Pre- and post-natal sensitivity. The rabbit developmental study 
indicates a concern for pre-natal sensitivity for infants and children 
and an acute dietary risk assessment was required (discussed below, 
under acute risk) for pregnant females 13+ years of age. The results of 
the rat developmental study do not indicate any concerns for pre-natal 
sensitivity for infants and children. Both the maternal and 
developmental NOELs were 1,000 mg/kg/day (highest dose tested).
    The results of the rat reproduction study did not demonstrate any 
concerns for post-natal sensitivity for infants and children. The 
parental and pup NOELs were both 75 mg/kg/day and at the LOELs of 396 
mg/kg/day, the decrease in body weight in the pups was also seen in the 
parental animals.
    e. Conclusion. Based on current toxicological data requirements, 
the data base for developmental and reproductive studies for HOE-107892 
is complete. The Agency concluded that the developmental and 
reproductive findings in rats did not demonstrate any pre-natal or 
post-natal acute risk concerns for infants and children. The Agency 
concluded that the observed developmental effects in the rabbit study 
present a pre-natal acute risk concern for infants and children and 
that an acute risk assessment was required to evaluate a margin of 
exposure . The acute risk assessment is described in detail below.
    2. Acute risk. The Agency concluded that the observed developmental 
effects in the rabbit study, abortions and fetal intrauterine death, 
present a pre-natal acute risk concern for infants and children. An 
acute dietary risk assessment evaluating margin of exposure (MOE) for 
women of childbearing age (13+ years old) is required when the Agency 
determines that there is a pre- or post- natal acute risk effect of 
concern. The acute dietary MOE for women of childbearing age is 10,000 
based on the rabbit developmental NOEL of 100 mg/kg/day and the high 
end human exposure value of 0.00006 mg/kg/day. This MOE is much higher 
than the minimal acceptable MOE of 100 for acute exposure to food. 
Despite the potential for acute exposure to HOE-107892 in drinking 
water, the Agency does not expect acute aggregate exposure to exceed it 
level of concern. EPA concludes that there is a reasonable certainty 
that no harm will result to infants and children from aggregate 
exposure to HOE-107892.
    3. Chronic risk. Using the conservative exposure assumptions 
described above, EPA has concluded that aggregate exposure to Herbicide 
safener HOE-107892 from food will utilize less than 0.01% of the RfD 
for infants and children. 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 Herbicide safener HOE-107892 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 Herbicide safener HOE-107892 residues.
    4. Short- or intermediate-term risk. Because no short- or 
intermediate-term non-dietary, non-occupational exposure scenario 
exists for HOE-107892, a short- or intermediate-term aggregate risk 
assessment is not required.

V. Other Considerations

A. Metabolism In Plants and Animals

    For purposes of the Section 18 use only, the nature of the residue 
for HOE-107892 in wheat is adequately understood. HOE-094270 was the 
major residue identified in grain, and HOE-094270 and HOE-113225 were 
the

[[Page 42683]]

major residues identified in straw. The residues of concern are HOE-
107892 and its metabolites HOE-094270 and HOE-113225.
    Because of the lack of quantifiable residues in wheat grain and 
straw, even at exaggerated treatment rates (up to 6.4x), and 
considering that this use is only for durum wheat, for purposes of this 
section 18 use only, the Agency will assume that there will be no 
quantifiable residues of the safener HOE-107892 or its metabolites in 
milk, meat, poultry or eggs resulting from this use.
    The maximum theoretical concentration factors for wheat bran and 
shorts are 7.7 and 8.4x respectively. Because residues in wheat grain 
treated at the 6.4x rate were nondetectable (less than 0.01 ppm), for 
purposes of this section 18 use only, the Agency will assume that 
residues in processed wheat commodities will also be nondetectable 
(less than 0.01 ppm).

B. Analytical Enforcement Methodology

    For purposes of this Section 18 use only, adequate enforcement 
methodology is available to quantify HOE-107892 and major metabolites 
in wheat grain and straw.

C. Magnitude of Residues

    Combined residues of HOE-107892 , HOE-094270 and HOE-113225 are not 
expected to exceed 0.01 ppm in wheat grain and 0.05 ppm in wheat straw 
as a result of this Section 18 use. Secondary residues of HOE-107892 
are not expected in animal commodities associated with this Section 18 
use.

D. International Residue Limits

    Italy has established a maximum residue limit (MRL) of 0.05 ppm in 
or on wheat grain for residues of HOE-109782.

VI. Conclusion

    Therefore, tolerances are established for HOE-107892 (mefenpyr-
diethyl) and its 2,4-dichlorophenyl-pyrazoline metabolites HOE-094270 
and HOE-113225 in wheat grain and wheat straw at 0.01 and 0.05 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 October 7, 1997, 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 
Confidential Business Information (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-300517] (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 (7506C), 
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:
    <a href="/cdn-cgi/l/email-protection#177867673a7378747c7263577267767a767e7b3972677639707861"><span class="__cf_email__" data-cfemail="ddb2adadf0b9b2beb6b8a99db8adbcb0bcb4b1f3b8adbcf3bab2ab">[email protected]</span></a>.


    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(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).

[[Page 42684]]

    In addition, since these tolerances and exemptions that are 
established on the basis of a petition under FFDCA section 408 (d), 
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 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: July 24, 1997.
James Jones,
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 180.509 is added to read as follows :


Sec. 180.509  HOE-107892 (mefenpyr-diethyl); tolerance for residues.

    (a) General. [Reserved]
    (b) Section 18 emergency exemptions. Time-limited tolerances are 
established for residues of the herbicide safener HOE-107892 (mefenpyr-
diethyl) and its 2,4-dichlorophenyl-pyrazoline metabolites HOE-094270 
and HOE-113225 in connection with use of the herbicide safener under 
Section 18 emergency exemptions granted by the EPA. The tolerances will 
expire and are revoked on the dates specified in the following table:

                                                                        
------------------------------------------------------------------------
                                                          Expiration/   
            Commodity              Parts per million    revocation date 
------------------------------------------------------------------------
Wheat grain.....................  0.01                August 1, 1998    
Wheat straw.....................  0.05                August 1, 1998    
------------------------------------------------------------------------

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

[FR Doc. 97-20844 Filed 8-7-97; 8:45 am]
BILLING CODE 6560-50-F


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