[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: [email protected]. Copies of objections and
hearing requests must be submitted as an ASCII file avoiding the use of
special characters and any form of encryption. Copies of objections and
hearing requests will also be accepted on disks in WordPerfect 5.1 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:
[email protected].
SUPPLEMENTARY INFORMATION: EPA, on its own initiative, pursuant to
section 408(e) and (l)(6) of the Federal Food, Drug, and Cosmetic Act
(FFDCA), 21 U.S.C. 346a(e) and (l)(6), is establishing 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:
[email protected].
Electronic comments must be submitted as an ASCII file avoiding the
use of special characters and any form of encryption.
The official record for this rulemaking, as well as the public
version, as described above will be kept in paper form. Accordingly,
EPA will transfer any copies of objections and hearing requests
received electronically into printed, paper form as they are received
and will place the paper copies in the official rulemaking record which
will also include all comments submitted directly in writing. The
official rulemaking record is the paper record maintained at the
Virginia address in ``ADDRESSES'' at the beginning of this document.
IX. Regulatory Assessment Requirements
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