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Bifenthrin. September 5, 1997. Pesticide Tolerances for Emergency Exemptions. Final Rule. Federal Register.
http://www.epa.gov/fedrgstr/EPA-PEST/1997/September/Day-05/p23720.htm
[Federal Register: September 5, 1997 (Volume 62, Number 172)]
[Rules and Regulations]
[Page 46894-46900]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr05se97-17]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
[OPP-300543; FRL-5740-6]
RIN 2070-AB78
Bifenthrin; 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
residues of bifenthrin in or on canola seed. This action is in response
to EPA's granting of an emergency exemption under section 18 of the
Federal Insecticide, Fungicide, and Rodenticide Act authorizing use of
the pesticide on canola in Idaho, Oregon, and Washington. This
regulation establishes a maximum permissible level for residues of
bifenthrin in this food commodity pursuant to section 408(l)(6) of the
Federal Food, Drug, and Cosmetic Act, as amended by the Food Quality
Protection Act of 1996. The tolerance will expire and is revoked on
September 30, 1998.
DATES: This regulation is effective September 5, 1997. Objections and
requests for hearings must be received by EPA on or before November 4,
1997.
ADDRESSES: Written objections and hearing requests, identified by the
docket control number, [OPP-300543], 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-300543], 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: opp-docket@epamail.epa.gov. Copies of objections and
hearing requests must be submitted as an ASCII file avoiding the use of
special characters and any form of encryption. Copies of objections and
hearing requests will also be accepted on disks in WordPerfect 5.1 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-300543]. No Confidential Business Information (CBI) should
be submitted through e-mail. Electronic copies of objections and
hearing requests on this rule may be filed online at many Federal
Depository Libraries.
FOR FURTHER INFORMATION CONTACT: By mail: Andrea Beard, Registration
Division 7505C, Office of Pesticide Programs, Environmental Protection
Agency, 401 M St., SW., Washington, DC 20460. Office location,
telephone number, and e-mail address: Crystal Mall #2, 1921 Jefferson
Davis Hwy., Arlington, VA, (703) 308-9356, e-mail:
beard.andrea@epamail.epa.gov.
SUPPLEMENTARY INFORMATION: EPA, on its own initiative, pursuant to
section 408(e) and (l)(6) of the Federal Food, Drug, and Cosmetic Act
(FFDCA), 21 U.S.C. 346a(e) and (l)(6), is establishing a tolerance for
residues of the insecticide bifenthrin, in or on canola seed at 0.5
part per million (ppm). This tolerance will expire and is revoked on
September 30, 1998. EPA will publish a document in the Federal Register
to remove the revoked tolerance from the Code of Federal Regulations.
I. Background and Statutory Authority
The Food Quality Protection Act of 1996 (FQPA) (Pub. L. 104-170)
was signed into law August 3, 1996. FQPA amends both the Federal Food,
Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 301 et seq., and the Federal
Insecticide, Fungicide, and Rodenticide Act (FIFRA), 7 U.S.C. 136 et
seq. The FQPA amendments went into effect immediately. Among other
things, FQPA amends FFDCA to bring all EPA pesticide tolerance-setting
activities under a new section 408 with a new
[[Page 46895]]
safety standard and new procedures. These activities are described
below and discussed in greater detail in the final rule establishing
the time-limited tolerance associated with the emergency exemption for
use of propiconazole on sorghum (61 FR 58135, November 13, 1996)(FRL-
5572-9).
New section 408(b)(2)(A)(i) of the FFDCA allows EPA to establish a
tolerance (the legal limit for a pesticide chemical residue in or on a
food) only if EPA determines that the tolerance is ``safe.'' Section
408(b)(2)(A)(ii) defines ``safe'' to mean that ``there is a reasonable
certainty that no harm will result from aggregate exposure to the
pesticide chemical residue, including all anticipated dietary exposures
and all other exposures for which there is reliable information.'' This
includes exposure through drinking water and in residential settings,
but does not include occupational exposure. Section 408(b)(2)(C)
requires EPA to give special consideration to exposure of infants and
children to the pesticide chemical residue in establishing a tolerance
and to ``ensure that there is a reasonable certainty that no harm will
result to infants and children from aggregate exposure to the pesticide
chemical residue....''
Section 18 of FIFRA authorizes EPA to exempt any Federal or State
agency from any provision of FIFRA, if EPA determines that ``emergency
conditions exist which require such exemption.'' This provision was not
amended by FQPA. EPA has established regulations governing such
emergency exemptions in 40 CFR part 166.
Section 408(l)(6) of the FFDCA requires EPA to establish a time-
limited tolerance or exemption from the requirement for a tolerance for
pesticide chemical residues in food that will result from the use of a
pesticide under an emergency exemption granted by EPA under section 18
of FIFRA. Such tolerances can be established without providing notice
or period for public comment.
Because decisions on section 18-related tolerances must proceed
before EPA reaches closure on several policy issues relating to
interpretation and implementation of the FQPA, EPA does not intend for
its actions on such tolerance to set binding precedents for the
application of section 408 and the new safety standard to other
tolerances and exemptions.
II. Emergency Exemption for Bifenthrin on Canola and FFDCA
Tolerances
The Applicants state that the events which brought about this
emergency situation started in 1992, when significant numbers of
cabbage aphid were first noted on the canola crop. Since then, numbers
of this pest have continued to build to where economic damage has
occurred in affected areas where bifenthrin was not applied. Registered
materials do not adequately control aphids in canola, and several have
the additional disadvantage of toxicity to beneficials. This situation
has been especially severe during the years with mild wet winters,
which allow high aphid carryover from the previous year, and delay
planting so that flowering of the canola occurs when aphid populations
are at their peak. EPA has authorized use of bifenthrin on canola for
this situation for the past 2 years. EPA has authorized under FIFRA
section 18 the use of bifenthrin on canola for control of aphids in
Idaho, Oregon, and Washington. After having reviewed the submission,
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 bifenthrin in or on
canola. 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
September 30, 1998, under FFDCA section 408(l)(5), residues of the
pesticide not in excess of the amounts specified in the tolerance
remaining in or on canola seed after that date will not be unlawful,
provided the pesticide is applied in a manner that was lawful under
FIFRA. EPA will take action to revoke this tolerance earlier if any
experience with, scientific data on, or other relevant information on
this pesticide indicate that the residues are not safe.
Because this tolerance is being approved under emergency conditions
EPA has not made any decisions about whether bifenthrin meets EPA's
registration requirements for use on canola or whether a permanent
tolerance for this use would be appropriate. Under these circumstances,
EPA does not believe that this tolerance serves as a basis for
registration of bifenthrin by a State for special local needs under
FIFRA section 24(c). Nor does this tolerance serve as the basis for any
State other than Idaho, Oregon, and Washington 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 bifenthrin, 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 percent or less of the
RfD) is generally considered acceptable by EPA. EPA generally uses the
RfD to evaluate the
[[Page 46896]]
chronic risks posed by pesticide exposure. For shorter term risks, EPA
calculates a margin of exposure (MOE) by dividing the estimated human
exposure into the NOEL from the appropriate animal study. Commonly, EPA
finds MOEs lower than 100 to be unacceptable. This 100-fold MOE is
based on the same rationale as the 100-fold uncertainty factor.
Lifetime feeding studies in two species of laboratory animals are
conducted to screen pesticides for cancer effects. When evidence of
increased cancer is noted in these studies, the Agency conducts a
weight of the evidence review of all relevant toxicological data
including short-term and mutagenicity studies and structure activity
relationship. Once a pesticide has been classified as a potential human
carcinogen, different types of risk assessments (e.g., linear low dose
extrapolations or MOE calculation based on the appropriate NOEL) will
be carried out based on the nature of the carcinogenic response and the
Agency's knowledge of its mode of action.
2. Differences in toxic effect due to exposure duration. The
toxicological effects of a pesticide can vary with different exposure
durations. EPA considers the entire toxicity data base, and based on
the effects seen for different durations and routes of exposure,
determines which risk assessments should be done to assure that the
public is adequately protected from any pesticide exposure scenario.
Both short and long durations of exposure are always considered.
Typically, risk assessments include ``acute'', ``short-term'',
``intermediate term'', and ``chronic'' risks. These assessments are
defined by the Agency as follows.
Acute risk, by the Agency's definition, results from 1-day
consumption of food and water, and reflects toxicity which could be
expressed following a single oral exposure to the pesticide residues.
High end exposure to food and water residues are typically assumed.
Short-term risk results from exposure to the pesticide for a period
of 1-7 days, and therefore overlaps with the acute risk assessment.
Historically, this risk assessment was intended to address primarily
dermal and inhalation exposure which could result, for example, from
residential pesticide applications. However, since enaction of FQPA,
this assessment has been expanded to include both dietary and non-
dietary sources of exposure, and will typically consider exposure from
food, water, and residential uses when reliable data are available. In
this assessment, risks from average food and water exposure, and high-
end residential exposure, are aggregated. High-end exposures from all 3
sources are not typically added because of the very low probability of
this occurring in most cases, and because the other conservative
assumptions built into the assessment assure adequate protection of
public health. However, for cases in which high-end exposure can
reasonably be expected from multiple sources (e.g. frequent and
widespread homeowner use in a specific geographical area), multiple
high-end risks will be aggregated and presented as part of the
comprehensive risk assessment/characterization. Since the toxicological
endpoint considered in this assessment reflects exposure over a period
of at least 7 days, an additional degree of conservatism is built into
the assessment; i.e., the risk assessment nominally covers 1-7 days
exposure, and the toxicological endpoint/NOEL is selected to be
adequate for at least 7 days of exposure. (Toxicity results at lower
levels when the dosing duration is increased.)
Intermediate-term risk results from exposure for 7 days to several
months. This assessment is handled in a manner similar to the short-
term risk assessment.
Chronic risk assessment describes risk which could result from
several months to a lifetime of exposure. For this assessment, risks
are aggregated considering average exposure from all sources for
representative population subgroups including infants and children.
B. Aggregate Exposure
In examining aggregate exposure, FFDCA section 408 requires that
EPA take into account available and reliable information concerning
exposure from the pesticide residue in the food in question, residues
in other foods for which there are tolerances, residues in groundwater
or surface water that is consumed as drinking water, and other non-
occupational exposures through pesticide use in gardens, lawns, or
buildings (residential and other indoor uses). Dietary exposure to
residues of a pesticide in a food commodity are estimated by
multiplying the average daily consumption of the food forms of that
commodity by the tolerance level or the anticipated pesticide residue
level. The Theoretical Maximum Residue Contribution (TMRC) is an
estimate of the level of residues consumed daily if each food item
contained pesticide residues equal to the tolerance. In evaluating food
exposures, EPA takes into account varying consumption patterns of major
identifiable subgroups of consumers, including infants and children.
The TMRC is a ``worst case'' estimate since it is based on the
assumptions that food contains pesticide residues at the tolerance
level and that 100% of the crop is treated by pesticides that have
established tolerances. If the TMRC exceeds the RfD or poses a lifetime
cancer risk that is greater than approximately one in a million, EPA
attempts to derive a more accurate exposure estimate for the pesticide
by evaluating additional types of information (anticipated residue data
and/or percent of crop treated data) which show, generally, that
pesticide residues in most foods when they are eaten are well below
established tolerances.
Percent of crop treated estimates are derived from Federal and
private market survey data. Typically, a range of estimates are
supplied and the upper end of this range is assumed for the exposure
assessment. By using this upper end estimate of percent of crop
treated, the Agency is reasonably certain that exposure is not
understated for any significant subpopulation group. Further, regional
consumption information is taken into account through EPA's computer-
based model for evaluating the exposure of significant subpopulations
including several regional groups, to pesticide residues. For this
pesticide, the most highly exposed population subgroup (Non-Nursing
Infants, less than 1 year old) was not regionally based.
IV. Aggregate Risk Assessment and Determination of Safety
Consistent with section 408(b)(2)(D), EPA has reviewed the
available scientific data and other relevant information in support of
this action, EPA has sufficient data to assess the hazards of
bifenthrin and to make a determination on aggregate exposure,
consistent with section 408(b)(2), for a time-limited tolerance for
residues of bifenthrin on canola seed at 0.5 ppm. EPA's assessment of
the dietary exposures and risks associated with establishing the
tolerance follows.
A. Toxicological Profile
EPA has evaluated the available toxicity data and considered its
validity, completeness, and reliability as well as the relationship of
the results of the studies to human risk. EPA has also considered
available information concerning the variability of the sensitivities
of major identifiable subgroups of consumers, including infants and
children. The nature of the toxic effects caused by bifenthrin are
discussed below.
[[Page 46897]]
1. Acute toxicity. The maternal NOEL of 1 mg/kg/day from the oral
developmental toxicity study in rats is used for acute dietary risk
assessments. The maternal LOEL of this study of 2 mg/kg/day was based
on tremors from day 7-17 of dosing. This acute dietary endpoint is used
to estimate dietary risks to all population subgroups.
2. Short - and intermediate - term toxicity. The maternal NOEL of
1 mg/kg/day from the oral developmental toxicity study in rats is also
used for short- and intermediate-term MOE calculations (as well as
acute, discussed in Unit IV.A.1. above).
3. Chronic toxicity. EPA has established the RfD for bifenthrin at
0.015 milligrams/kilogram/day (mg/kg/day). This RfD is based on a 1-
year oral feeding study in dogs with a NOEL of 1.5 mg/kg/day, based on
intermittent tremors at the LOEL of 3 mg/kg/day; an uncertainty factor
of 100 is used.
4. Carcinogenicity. OPP has classified bifenthrin as a Group C
chemical (possible human carcinogen) based upon urinary bladder tumors
in mice, but did not recommend assignment of a Q*.
B. Exposures and Risks
1. From food and feed uses. Tolerances have been established (40
CFR 180.442) for the residues of bifenthrin, in or on a variety of raw
agricultural commodities. Tolerances, in support of registrations,
currently exist for residues of bifenthrin on hops; strawberries; corn
grain, forage, and fodder; cotton seed; and livestock commodities of
cattle, goats, hogs, horses, sheep, and poultry. Additionally, time-
limited tolerances associated with emergency exemptions were recently
established for broccoli, cauliflower, raspberries, and cucurbits. Risk
assessments were conducted by EPA to assess dietary exposures and risks
from bifenthrin as follows:
i. Acute exposure and risk. Acute dietary risk assessments are
performed for a food-use pesticide if a toxicological study has
indicated the possibility of an effect of concern occurring as a result
of a one day or single exposure. [The acute risk assessment used
anticipated residues for all commodities having bifenthrin tolerances,
except for cucurbits and raspberries, for which tolerance level
residues were used. For the most highly exposed population subgroup,
children 1-6 years old, the resulting high-end exposure results in a
dietary (food only) MOE of 33; at the 97th percentile the MOE is 111.
For infants < 1 year old, the high-end exposure MOE is 50; at the 98th
percentile it is 111. For the overall U.S. population, the high-end
exposure MOE is 50; at the 99th percentile it is 111. The major portion
of the estimated dietary exposure from bifenthrin is contributed
through the tolerances for field corn and secondary residues in animal
commodities resulting from feeding of the treated field corn. This
assessment used the extremely conservative assumption that 100% of the
field corn and livestock commodities would contain residues of
bifenthrin. However, available data show that of the total field corn
crop grown in the United States, only about 0.45 percent was actually
treated with bifenthrin in 1994-96 (3-year average); it is expected
that a similar percentage will be treated for the current year (1997),
since this figure has generally remained consistent for the past 3
years. Therefore, it is likely that the actual exposure is considerably
less than the conservative estimates given here; if these estimates
were refined using the Monte Carlo technique and incorporating actual
percent of crop treated figures, EPA scientists believe that the MOEs
would be increased to acceptable levels for the high-end consumer.
ii. Short- and intermediate-term risk. The short- and intermediate-
term risk assessment used maximum anticipated residue levels for
cotton, extrapolated residue levels for meat/milk/poultry/eggs, and air
monitoring data collected from 15 homes in four states. Based on this
data, the MOEs for children are calculated to be 280 for the average
consumer and 250 for the high-end consumer. The MOEs for adults are
calculated to be 450 for the average consumer and 390 for the high-end
consumer. EPA generally has no concern for MOEs greater than 100, and
thus these do not exceed EPA's level of concern.
iii. Chronic exposure and risk. The chronic dietary (food only)
risk assessment for bifenthrin was conducted using the extremely
conservative TMRC exposure assumptions that 100% of canola commodities
and all other commodities having bifenthrin tolerances will contain
bifenthrin residues at tolerance levels. Based on this, EPA has
concluded that dietary exposure to bifenthrin will utilize 29 percent
of the RfD for the Overall US Population (4 percent of this attributed
to canola). The major identifiable subgroup with the highest exposure
is Non-Nursing Infants < 1 year old, at 62 percent of the RfD. This is
further discussed below in the section on infants and children. EPA
generally has no concern for exposure below 100 percent 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 bifenthrin in
drinking water, EPA does not expect the aggregate exposure to exceed
100 percent of the RfD. EPA concludes that there is a reasonable
certainty that no harm will result from chronic aggregate exposure to
bifenthrin residues.
2. From drinking water. Because the Agency lacks sufficient water-
related exposure data to complete a comprehensive drinking water risk
assessment for many pesticides, EPA has commenced and nearly completed
a process to identify a reasonable yet conservative bounding figure for
the potential contribution of water-related exposure to the aggregate
risk posed by a pesticide. In developing the bounding figure, EPA
estimated residue levels in water for a number of specific pesticides
using various data sources. The Agency then applied the estimated
residue levels, in conjunction with appropriate toxicological endpoints
(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 bifenthrin 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 bifenthrin in water, even at the higher levels the Agency is
considering as a conservative upper bound, would not prevent the Agency
from determining that there is a reasonable certainty of no harm if the
tolerance is granted.
3. From non-dietary exposure. Bifenthrin is currently only
registered for residential non-food use as a termiticide. Based on
information referred to above regarding short- and intermediate-term
exposure, this use is not expected to result in risks that exceed
levels of concern. Therefore, reasonable certainty of no harm is
expected from exposure through non-dietary, non-occupational routes.
4. Cumulative exposure to substances with common mechanism of
toxicity. Section 408(b)(2)(D)(v) requires that, when considering
whether to establish, modify, or revoke a tolerance, the Agency
consider ``available information'' concerning the cumulative effects of
a particular pesticide's residues and ``other substances that
[[Page 46898]]
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 bifenthrin 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,
bifenthrin 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 bifenthrin has a common mechanism of toxicity
with other substances.
C. Aggregate Risks and Determination of Safety for U.S. Population
1. Acute risk. For the overall U.S. population, the calculated MOE
value (for food only) is 50. For the most highly exposed subgroup,
children 1 - 6 years old, the MOE for food is 33. As stated above, EPA
believes that with percent of crop treated (particularly for field
corn, the major contributor) incorporated in a Monte Carlo analysis,
MOEs for all population subgroups will be acceptable. Although
theoretically there is the potential for exposure to bifenthrin in
drinking water, EPA does not expect that exposure would result in
aggregate MOEs (food plus water) that would exceed the levels of
concern for acute dietary exposure. Therefore, EPA concludes that there
is reasonable certainty that no harm will result from acute exposure to
bifenthrin.
2. Chronic risk. Using the TMRC exposure assumptions described
above, EPA has concluded that aggregate exposure to bifenthrin from
food will utilize 29 of the RfD for the U.S. population. The major
identifiable subgroup with the highest aggregate exposure is non-
nursing infants < 1 year old, discussed below. EPA generally has no
concern for exposures below 100% of the RfD because the RfD represents
the level at or below which daily aggregate dietary exposure over a
lifetime will not pose appreciable risks to human health. Despite the
potential for exposure to bifenthrin 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 chronic aggregate
exposure to bifenthrin residues.
3. Short- and intermediate-term risk. Short- and intermediate-term
aggregate exposure takes into account chronic dietary food and water
(considered to be a background exposure level) plus indoor and outdoor
residential exposure. Based on bifenthrin not being registered for
indoor residential or pet uses, EPA concludes that the aggregate short-
and intermediate-term risks do not exceed levels of concern, and that
there is reasonable certainty that no harm will result.
D. Aggregate Risks and Determination of Safety for Infants and Children
1. Safety factor for infants and children--i. In general. In
assessing the potential for additional sensitivity of infants and
children to residues of bifenthrin, EPA considered data from
developmental toxicity studies in the rat and rabbit and a two-
generation reproduction study in the rat. The developmental toxicity
studies are designed to evaluate adverse effects on the developing
organism resulting from maternal pesticide exposure during gestation.
Reproduction studies provide information relating to effects from
exposure to the pesticide on the reproductive capability of mating
animals and data on systemic toxicity.
FFDCA section 408 provides that EPA shall apply an additional
tenfold margin of safety for infants and children in the case of
threshold effects to account for pre-and post-natal toxicity and the
completeness of the database unless EPA determines that a different
margin of safety will be safe for infants and children. Margins of
safety are incorporated into EPA risk assessments either directly
through use of a MOE analysis or through using uncertainty (safety)
factors in calculating a dose level that poses no appreciable risk to
humans. EPA believes that reliable data support using the standard 100-
fold safety factor (usually 100 for combined inter- and intra-species
variability)) and not the additional tenfold safety factor when EPA has
a complete data base under existing guidelines and when the severity of
the effect in infants or children or the potency or unusual toxic
properties of a compound do not raise concerns regarding the adequacy
of the standard MOE/safety factor.
ii. Developmental toxicity studies. In the rabbit developmental
study, there were no developmental effects observed in the fetuses
exposed to bifenthrin. The maternal NOEL was 2.67 mg/kg/day based on
head and forelimb twitching at the LOEL of 4 mg/kg/day. In the rat
developmental study, the maternal NOEL was 1 mg/kg/day, based on
tremors at the LOEL of 2 mg/kg/day. The developmental (pup) NOEL was
also 1 mg/kg/day, based upon increased incidence of hydroureter at the
LOEL of 2 mg/kg/day. There were 5/23 (22%) of the litters affected (5/
141 fetuses since each litter only had one affected fetus) in the 2 mg/
kg/day group, compared with zero in the control, 1, and 0.5 mg/kg/day
groups. According to recent historical data (1992-1994) for this strain
of rat, background incidence of distended ureter averaged 11% with a
maximum incidence of 90%.
iii. Reproductive toxicity study. In the rat reproduction study,
parental toxicity occurred as decreased body weight at 5.0 mg/kg/day
with a NOEL of 3.0 mg/kg/day. There were no developmental (pup) or
reproductive effects up to 5.0 mg/kg/day (highest dose tested).
[[Page 46899]]
iv. Pre- and post-natal sensitivity--a. Pre-natal. Since there was
not a dose-related finding of hydroureter in the rat developmental
study and in the presence of similar incidences in the recent
historical control data, the marginal finding of hydroureter in rat
fetuses at 2 mg/kg/day (in the presence of maternal toxicity) is not
considered a significant developmental finding. Nor does it provide
sufficient evidence of a special dietary risk (either acute or chronic)
for infants and children which would require an additional safety
factor.
b. Post-natal. Based on the absence of pup toxicity up to dose
levels which produced toxicity in the parental animals, there is no
evidence of special post-natal sensitivity to infants and children in
the rat reproduction study.
v. Conclusion. Based on the above, EPA concludes that reliable data
support use of the standard 100-fold uncertainty factor, and that an
additional uncertainty factor is not needed to protect the safety of
infants and children.
2. Acute risk. EPA believes that residential exposures are more
appropriately included in the short-term exposure scenario, and thus
estimates acute risk from dietary exposure only. EPA concluded that
aggregate dietary acute risk (food plus water) would not exceed levels
of concern. This is discussed in greater detail above.
3. Chronic risk. Using the conservative exposure assumptions
described above, EPA has concluded that aggregate exposure to
bifenthrin from food will utilize from 20 to 62 percent 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 bifenthrin 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
bifenthrin residues.
4. Short- or intermediate-term risk. The estimated short- and
intermediate-term risks do not exceed EPA's levels of concern for
children. MOEs for children are calculated to be 280 for the average
consumer and 250 for the high-end consumer, discussed in greater detail
above.
V. Other Considerations
A. Metabolism In Plants and Animals
The metabolism of bifenthrin in canola is adequately understood for
the purposes of these tolerances. The residue of concern is the parent
compound only.
B. Analytical Enforcement Methodology
There is a practical analytical method for detecting and measuring
levels of bifenthrin in or on food with a limit of detection that
allows monitoring of food with residues at or above the levels set in
this tolerance document (Gas chromatography with Electron Capture
Detection, analytical method P-2132M, PP#0E3921; MRID#41658601). EPA
has provided information on this method to Food and Drug
Administration. The method is available to anyone who is interested
from OPP's Health Effects Division, 7509C Office of Pesticide Programs,
Environmental Protection Agency, 401 M St., SW., Washington, DC 20460.
C. Magnitude of Residues
Residues of bifenthrin are not likely to exceed 0.5 ppm in or on
canola seed, meal , and refined oil as a result of the proposed use.
Secondary residues in animal commodities are not expected to exceed
already established tolerances.
D. International Residue Limits
There are no Codex, Canadian, or Mexican residue limits for
residues of bifenthrin in or on canola seed, meal, or refined oil.
E. Rotational Crop Restrictions
The confined rotational crop data requirements for bifenthrin have
been satisfied. The following rotation instructions are required: (1)
Leafy vegetables and root crops may be rotated 30 days following the
final application of bifenthrin; (2) Crops for which bifenthrin
tolerances exist may be rotated at any time; and (3) All other crops
may be rotated 7 months following the final application of bifenthrin .
VI. Conclusion
Therefore, the tolerance is established for residues of bifenthrin
in canola seed at 0.5 ppm.
VII. Objections and Hearing Requests
The new FFDCA section 408(g) provides essentially the same process
for persons to ``object'' to a tolerance regulation issued by EPA under
new section 408(e) and (l)(6) as was provided in the old section 408
and in section 409. However, the period for filing objections is 60
days, rather than 30 days. EPA currently has procedural regulations
which govern the submission of objections and hearing requests. These
regulations will require some modification to reflect the new law.
However, until those modifications can be made, EPA will continue to
use those procedural regulations with appropriate adjustments to
reflect the new law.
Any person may, by November 4, 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 Record
EPA has established a record for this rulemaking under docket
control number [OPP-300543] (including any comments and data submitted
electronically). A public version of this
[[Page 46900]]
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 Highway,
Arlington, VA.
Electronic comments may be sent directly to EPA at:
opp-docket@epamail.epa.gov.
Electronic comments must be submitted as an ASCII file avoiding the
use of special characters and any form of encryption.
The official record for this rulemaking, as well as the public
version, as described above will be kept in paper form. Accordingly,
EPA will transfer any copies of objections and hearing requests
received electronically into printed, paper form as they are received
and will place the paper copies in the official rulemaking record which
will also include all comments submitted directly in writing. The
official rulemaking record is the paper record maintained at the
Virginia address in ``ADDRESSES'' at the beginning of this document.
IX. Regulatory Assessment Requirements
This final rule establishes a time-limited tolerance under FFDCA
section 408(d). The Office of Management and Budget (OMB) has exempted
these types of actions from review under Executive Order 12866,
entitled Regulatory Planning and Review (58 FR 51735, October 4, 1993).
This final rule does not contain any information collections subject to
OMB approval under the Paperwork Reduction Act (PRA), 44 U.S.C. 3501 et
seq., or impose any enforceable duty or contain any unfunded mandate as
described under Title II of the Unfunded Mandates Reform Act of 1995
(UMRA) (Pub. L. 104-4). Nor does it require any prior consultation as
specified by Executive Order 12875, entitled Enhancing the
Intergovernmental Partnership (58 FR 58093, October 28, 1993), or
special considerations as required by Executive Order 12898, entitled
Federal Actions to Address Environmental Justice in Minority
Populations and Low-Income Populations (59 FR 7629, February 16, 1994),
or require OMB review in accordance with Executive Order 13045,
entitled Protection of Children from Environmental Health Risks and
Safety Risks (62 FR 19885, April 23, 1997).
In addition, since these tolerances and exemptions that are
established under FFDCA section 408 (l)(6), such as the tolerance in
this final rule, do not require the issuance of a proposed rule, the
requirements of the Regulatory Flexibility Act (RFA) (5 U.S.C. 601 et
seq.) do not apply. Nevertheless, the Agency has previously assessed
whether establishing tolerances, exemptions from tolerances, raising
tolerance levels or expanding exemptions might adversely impact small
entities and concluded, as a generic matter, that there is no adverse
economic impact. The factual basis for the Agency's 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: August 26, 1997.
Peter Caulkins,
Acting Director, Registration Division, Office of Pesticide Programs.
Therefore, 40 CFR chapter I is amended as follows:
PART 180--[AMENDED]
1. The authority citation for part 180 continues to read as
follows:
Authority : 21 U.S.C. 346a and 371.
2. In Sec. 180.442, by alphabetically inserting the following item
into the table in paragraph (b) to read as follows:
Sec. 180.442 Bifenthrin; tolerances for residues.
* * * * *
(b) * * *
------------------------------------------------------------------------
Expiration/
Commodity Parts per million Revocation Date
------------------------------------------------------------------------
Canola, Seed.................... 0.5 9/30/98
* * * * * * *
------------------------------------------------------------------------
* * * * *
[FR Doc. 97-23720 Filed 9-4-97; 8:45 am]
BILLING CODE 6560-50-F