[Federal Register Volume 63, Number 150 (Wednesday, August 5, 1998)]
[Rules and Regulations]
[Pages 41720-41727]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-20906]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
[OPP-300689; FRL-6018-5]
RIN 2070-AB78
Buprofezin; Pesticide Tolerances for Emergency Exemptions
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
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SUMMARY: This regulation establishes time-limited tolerances for
residues of buprofezin in or on cucurbits, tomatoes and tomato paste.
This action is in response to EPA's granting of emergency exemptions
under section 18 of the Federal Insecticide, Fungicide, and Rodenticide
Act authorizing use of the pesticide on cucurbits and tomatoes. This
regulation establishes a maximum permissible level for residues of
buprofezin in these food commodities pursuant to section 408(l)(6) of
the Federal Food, Drug, and Cosmetic Act, as amended by the Food
Quality Protection Act of 1996. These tolerances will expire and are
revoked on December 31, 1999.
DATES: This regulation is effective August 5, 1998. Objections and
requests for hearings must be received by EPA on or before October 5,
1998.
ADDRESSES: Written objections and hearing requests, identified by the
docket control number, [OPP-300689], 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-300689], must also be submitted to: Public
Information and Records Integrity Branch, Information Resources and
Services Division (7502C), Office of Pesticide Programs, Environmental
Protection Agency, 401 M St., SW., Washington, DC 20460. In person,
bring a copy of objections and hearing requests to Rm. 119, CM #2, 1921
Jefferson Davis Hwy., Arlington, VA.
A copy of objections and hearing requests filed with the Hearing
Clerk may also be submitted electronically by sending electronic mail
(e-mail) to: opp-docket@epamail.epa.gov. Copies of objections and
hearing requests must be submitted as an ASCII file avoiding the use of
special characters and any form of encryption. Copies of objections and
hearing requests will also be accepted on disks in WordPerfect 5.1/6.1
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-300689]. 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: Andrew Ertman, 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) 308-9367, e-mail:
ertman.andrew@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 tolerances for
residues of the insecticide buprofezin, in or on cucurbits at 0.5 parts
per million (ppm), tomatoes at 0.7 ppm, and tomato paste at 1.0 ppm.
These tolerances will expire and are revoked on December 31, 1999. EPA
will publish a document in the Federal Register to remove the revoked
tolerances from the Code of Federal Regulations.
I. Background and Statutory Authority
The Food Quality Protection Act of 1996 (FQPA) (Pub. L. 104-170)
was signed into law August 3, 1996. FQPA amends both the Federal Food,
Drug, and Cosmetic Act (FFDCA), 21 U.S.C.
[[Page 41721]]
301 et seq., and the Federal Insecticide, Fungicide, and Rodenticide
Act (FIFRA), 7 U.S.C. 136 et seq. The FQPA amendments went into effect
immediately. Among other things, FQPA amends FFDCA to bring all EPA
pesticide tolerance-setting activities under a new section 408 with a
new safety standard and new procedures. These activities are described
below and discussed in greater detail in the final rule establishing
the time-limited tolerance associated with the emergency exemption for
use of propiconazole on sorghum (61 FR 58135, November 13, 1996)(FRL-
5572-9).
New section 408(b)(2)(A)(i) of the FFDCA allows EPA to establish a
tolerance (the legal limit for a pesticide chemical residue in or on a
food) only if EPA determines that the tolerance is ``safe.'' Section
408(b)(2)(A)(ii) defines ``safe'' to mean that ``there is a reasonable
certainty that no harm will result from aggregate exposure to the
pesticide chemical residue, including all anticipated dietary exposures
and all other exposures for which there is reliable information.'' This
includes exposure through drinking water and in residential settings,
but does not include occupational exposure. Section 408(b)(2)(C)
requires EPA to give special consideration to exposure of infants and
children to the pesticide chemical residue in establishing a tolerance
and to ``ensure that there is a reasonable certainty that no harm will
result to infants and children from aggregate exposure to the pesticide
chemical residue. . . .''
Section 18 of FIFRA authorizes EPA to exempt any Federal or State
agency from any provision of FIFRA, if EPA determines that ``emergency
conditions exist which require such exemption.'' This provision was not
amended by FQPA. EPA has established regulations governing such
emergency exemptions in 40 CFR part 166.
Section 408(l)(6) of the FFDCA requires EPA to establish a time-
limited tolerance or exemption from the requirement for a tolerance for
pesticide chemical residues in food that will result from the use of a
pesticide under an emergency exemption granted by EPA under section 18
of FIFRA. Such tolerances can be established without providing notice
or period for public comment.
Because decisions on section 18-related tolerances must proceed
before EPA reaches closure on several policy issues relating to
interpretation and implementation of the FQPA, EPA does not intend for
its actions on such tolerance to set binding precedents for the
application of section 408 and the new safety standard to other
tolerances and exemptions.
II. Emergency Exemption for Buprofezin on Cucurbits and FFDCA
Tolerances
Buprofezin was requested for use on cucurbits in Arizona to control
whiteflies. The applicant states that the whitefly has been a major
pest in Arizona since the late 1980's and has caused significant
economic loss in a host of crops throughout the region. In Arizona,
without efficacious control of whitefly, losses top $30 million
annually to the watermelon and cantaloupe industries.
The host range for whitefly is broad and includes such commercial
crops as cotton, melons and other cucurbit crops, cole crops, tomatoes,
leafy vegetables, alfalfa and citrus. Urban ornamental plantings (such
as lantana, hibiscus, brittlebush, rose, mints, etc.) and native
vegetation (cheeseweed, mallows, etc.) are also host crops for the
whitefly. The year round availability of hosts provides the foundation
for an endemic population of whitefly, given the right environmental
conditions and a lack of effective registered pesticides to suppress or
control populations. What makes Arizona an excellent area for the
commercial production of a variety of agricultural crops also makes it
ideal for the annual survival of the whitefly.
Feeding whiteflies extract critical crop nutrients causing
defoliation, stunting and yield losses. In addition, quality losses are
common in commercial crops as the feeding whitefly excretes a ``sticky
honeydew'' that promotes the development of black sooty mold. Both the
mold development and the ``stickiness'' result in quality (economic)
losses in addition to the economic loss inherent in reduced yields.
Whiteflies are also vectors of disease, cause physiological disorders,
and exacerbate a host of other production problems including increased
plant stress leading to increased water and nutrient needs. The
constant use of broad-spectrum insecticides for the control of this
pest can lead to further damage by secondary pests such as aphids and
mites. Finally, the continued and repeated use of the same or similar
classes of insecticides has lead rapidly to the development of
resistance in whiteflies.
Buprofezin was also requested for use on tomatoes in Florida to
control the silverleaf whitefly. Tomatoes are produced and harvested
year-round in Florida. Tomato seedlings are grown in planthouses and
transplanted to fields. Silverleaf whitefly is a key pest on tomatoes
from the seedling stage through harvest in Florida year-round in all
production regions. High populations feeding on plants cause irregular
ripening, reducing fruit value. Whiteflies may also transmit tomato
mottle geminivirus (TMV) and tomato yellow leaf curl virus (TYLCV)
during feeding. TYLCV was discovered in tomatoes in Florida in the
summer of 1997 and is, therefore, a new pest-related problem. Because
whitefly is such a good vector of the virus and the virus is so
prevalent, only minimal infestations of whitefly are required to
transmit TYLCV to tomato plants.
Alternative control practices include cultural control methods,
natural enemies, and resistant varieties. Removal of alternate and
overwintering host plants, use of trap crops, use of reflective
mulches, and planting of windbreaks have not resulted in adequate
whitefly control. Natural enemies suppress whitefly but, alone, do not
provide adequate control. Buprofezin and pyriproxifen, because they are
IGRs that only affect immature insect development or development of
eggs, are less detrimental to natural enemies than are broad-spectrum
insecticides. Resistant tomato varieties adapted to the Florida climate
have not been developed.
No effective registered insecticides are available in Florida to
manage Silverleaf Whitefly. In order to prevent spread of TYLCV,
whitefly populations must be kept at a minimal level from transplanted
seedling stage through harvest (up to 110 days). Systemic imidacloprid
was very effective for controlling irregular ripening and TMV caused by
whitefly before TYLCV became a problem in Florida. Because imidacloprid
is only applied once and does not protect plants for the first two
weeks after transplanting or for the last several weeks before harvest,
it does not provide whitefly control required to prevent TYLCV
infection of plants. Up to two applications each of both buprofezin and
pyriproxifen will be required for protection of plants for the entire
growing season. Field testing in Florida has demonstrated that whitefly
has developed an unacceptable level of resistance to recommended foliar
pyrethroids, methamidophos, and other registered products. EPA has
authorized under FIFRA section 18 the use of buprofezin on cucurbits
for control of whiteflies in Arizona and tomatoes for control of the
silverleaf whitefly in Florida. 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
[[Page 41722]]
potential risks presented by residues of buprofezin in or on cucurbits
and tomatoes. In doing so, EPA considered the new safety standard in
FFDCA section 408(b)(2), and EPA decided that the necessary tolerances
under FFDCA section 408(l)(6) would be consistent with the new safety
standard and with FIFRA section 18. Consistent with the need to move
quickly on the emergency exemptions in order to address an urgent non-
routine situation and to ensure that the resulting food is safe and
lawful, EPA is issuing these tolerances without notice and opportunity
for public comment under section 408(e), as provided in section
408(l)(6). Although these tolerances will expire and are revoked on
December 31, 1999, under FFDCA section 408(l)(5), residues of the
pesticide not in excess of the amounts specified in the tolerances
remaining in or on cucurbits, tomatoes, and tomato paste after that
date will not be unlawful, provided the pesticide is applied in a
manner that was lawful under FIFRA, and the residues do not exceed a
level that was authorized by these tolerances at the time of that
application. EPA will take action to revoke these tolerances earlier if
any experience with, scientific data on, or other relevant information
on this pesticide indicate that the residues are not safe.
Because these tolerances are being approved under emergency
conditions EPA has not made any decisions about whether buprofezin
meets EPA's registration requirements for use on cucurbits or tomatoes
or whether permanent tolerances for these uses would be appropriate.
Under these circumstances, EPA does not believe that these tolerances
serve as a basis for registration of buprofezin by a State for special
local needs under FIFRA section 24(c). Nor do these tolerances serve as
the basis for any State other than Arizona and Florida to use this
pesticide on these crops 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
buprofezin, contact the Agency's Registration Division at the address
provided above.
III. Risk Assessment and Statutory Findings
EPA performs a number of analyses to determine the risks from
aggregate exposure to pesticide residues. First, EPA determines the
toxicity of pesticides based primarily on toxicological studies using
laboratory animals. These studies address many adverse health effects,
including (but not limited to) reproductive effects, developmental
toxicity, toxicity to the nervous system, and carcinogenicity. Second,
EPA examines exposure to the pesticide through the diet (e.g., food and
drinking water) and through exposures that occur as a result of
pesticide use in residential settings.
A. Toxicity
1. Threshold and non-threshold effects. For many animal studies, a
dose response relationship can be determined, which provides a dose
that causes adverse effects (threshold effects) and doses causing no
observed effects (the ``no-observed effect level'' or ``NOEL'').
Once a study has been evaluated and the observed effects have been
determined to be threshold effects, EPA generally divides the NOEL from
the study with the lowest NOEL by an uncertainty factor (usually 100 or
more) to determine the Reference Dose (RfD). The RfD is a level at or
below which daily aggregate exposure over a lifetime will not pose
appreciable risks to human health. An uncertainty factor (sometimes
called a ``safety factor'') of 100 is commonly used since it is assumed
that people may be up to 10 times more sensitive to pesticides than the
test animals, and that one person or subgroup of the population (such
as infants and children) could be up to 10 times more sensitive to a
pesticide than another. In addition, EPA assesses the potential risks
to infants and children based on the weight of the evidence of the
toxicology studies and determines whether an additional uncertainty
factor is warranted. Thus, an aggregate daily exposure to a pesticide
residue at or below the RfD (expressed as 100% or less of the RfD) is
generally considered acceptable by EPA. EPA generally uses the RfD to
evaluate the chronic risks posed by pesticide exposure. For shorter
term risks, EPA calculates a margin of exposure (MOE) by dividing the
estimated human exposure into the NOEL from the appropriate animal
study. Commonly, EPA finds MOEs lower than 100 to be unacceptable. This
100-fold MOE is based on the same rationale as the 100-fold uncertainty
factor.
Lifetime feeding studies in two species of laboratory animals are
conducted to screen pesticides for cancer effects. When evidence of
increased cancer is noted in these studies, the Agency conducts a
weight of the evidence review of all relevant toxicological data
including short-term and mutagenicity studies and structure activity
relationship. Once a pesticide has been classified as a potential human
carcinogen, different types of risk assessments (e.g., linear low dose
extrapolations or MOE calculation based on the appropriate NOEL) will
be carried out based on the nature of the carcinogenic response and the
Agency's knowledge of its mode of action.
2. Differences in toxic effect due to exposure duration. The
toxicological effects of a pesticide can vary with different exposure
durations. EPA considers the entire toxicity data base, and based on
the effects seen for different durations and routes of exposure,
determines which risk assessments should be done to assure that the
public is adequately protected from any pesticide exposure scenario.
Both short and long durations of exposure are always considered.
Typically, risk assessments include ``acute,'' ``short-term,''
``intermediate term,'' and ``chronic'' risks. These assessments are
defined by the Agency as follows.
Acute risk, by the Agency's definition, results from 1-day
consumption of food and water, and reflects toxicity which could be
expressed following a single oral exposure to the pesticide residues.
High end exposure to food and water residues are typically assumed.
Short-term risk results from exposure to the pesticide for a period
of 1-7 days, and therefore overlaps with the acute risk assessment.
Historically, this risk assessment was intended to address primarily
dermal and inhalation exposure which could result, for example, from
residential pesticide applications. However, since enaction of FQPA,
this assessment has been expanded to include both dietary and non-
dietary sources of exposure, and will typically consider exposure from
food, water, and residential uses when reliable data are available. In
this assessment, risks from average food and water exposure, and high-
end residential exposure, are aggregated. High-end exposures from all
three sources are not typically added because of the very low
probability of this occurring in most cases, and because the other
conservative assumptions built into the assessment assure adequate
protection of public health. However, for cases in which high-end
exposure can reasonably be expected from multiple sources (e.g.
frequent and widespread homeowner use in a specific geographical area),
multiple high-end risks will be aggregated and presented as part of the
comprehensive risk assessment/characterization. Since the toxicological
endpoint considered in this assessment reflects exposure over a period
of at least 7 days, an additional degree of conservatism is built into
the
[[Page 41723]]
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
buprofezin and to make a determination on aggregate exposure,
consistent with section 408(b)(2), for time-limited tolerances for
residues of buprofezin on cucurbits at 0.5 ppm, tomatoes at 0.7 ppm,
and tomato paste at 1.0 ppm. EPA's assessment of the dietary exposures
and risks associated with establishing the tolerances follows.
A. Toxicological Profile
EPA has evaluated the available toxicity data and considered its
validity, completeness, and reliability as well as the relationship of
the results of the studies to human risk. EPA has also considered
available information concerning the variability of the sensitivities
of major identifiable subgroups of consumers, including infants and
children. The nature of the toxic effects caused by buprofezin are
discussed below.
1. Acute toxicity. Acute RfD = 0.67 mg/kg/day; NOEL = 200 mg/kg/
day. For acute dietary risk assessment, the Agency determined that the
rat developmental NOEL of 200 milligrams/kilogram/day (mg/kg/day),
based on decreased fetal body weight and delayed ossification, at the
LOEL of 800 mg/kg/day, from the rat developmental study should be used
for the acute dietary risk assessment. This risk assessment will
evaluate developmental risks to females 13+ years of age. An MOE of 300
is required (a factor of 3 for FQPA considerations plus a factor of 100
to account for inter-species extrapolation and intra-species
variability).
2. Short - and intermediate - term toxicity. The Agency determined
that the maternal NOEL of 50 mg/kg/day in the rabbit developmental
study based on decreases in body weight and food consumption at the
LOEL of 250 mg/kg/day should be used for short and intermediate-term
exposure scenarios for both dermal and inhalation exposure. MOEs of 100
are required.
3. Chronic toxicity. EPA has established the RfD for buprofezin at
0.006 mg/kg/day. This RfD is based on a 2-year feeding study in dogs
with a NOEL of 2.0 mg/kg/day and an uncertainty factor of 300 a factor
of 3 for FQPA considerations, due to inadequate reproduction study, and
a factor of 100 to account for inter-species extrapolation and intra-
species variability based on a increased liver weight, increased liver
enzymes, and bile duct hyperplasia at the LOEL of 20.0 mg/kg/day.
4. Carcinogenicity. Buprofezin has not been evaluated by the OPP's
Hazard ID Committee. However, buprofezin will be likely be evaluated by
the OPP Cancer Peer Review Committee based on lung and liver tumors in
the mouse carcinogenicity study. For the purposes of these section 18
requests, the Agency calculated the cancer risk for buprofezin. The
male mouse Q2* based on combined lung tumors is 2.747 x
10-3. The female mouse Q1* on combined tumors is
2.488 x 10-3.
B. Exposures and Risks
1. From food and feed uses. Section 18 time limited tolerances (40
CFR 180.511) have been established for the residues of buprofezin at
1.0 ppm in or on cotton seed; 2 ppm in citrus fruit; 10 ppm in dried
citrus pulp; 20 ppm in cotton gin byproducts; 0.5 ppm in meat
byproducts of cattle, goats, hogs, horse, and sheep; 0.02 ppm in the
meat and fat of cattle, goats, hogs, horse, and sheep; and 0.03 ppm in
milk. No permanent tolerances have been established. Risk assessments
were conducted by EPA to assess dietary exposures and risks from
buprofezin 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 (food only) risk
assessment used the TMRC. Since for acute dietary risk assessment, the
acute effect is based on decreased fetal body weight and delayed
ossification, the population subgroup of concern is females 13+ years
of age. For this subgroup, an MOE value of 20,000 (equivalent to 1.5%
of the acute RfD) was calculated using the high-end exposure value of
0.01 mg/kg/day. This result should be viewed as a conservative risk
estimate.
[[Page 41724]]
ii. Chronic exposure and risk. In conducting this chronic dietary
risk assessment, EPA has made very conservative assumptions -- 100% of
cucurbits and tomatoes having buprofezin tolerances will contain
buprofezin residues and those residues would be at the level of the
tolerance -- which result in an overestimation of human dietary
exposure. Thus, in making a safety determination for this tolerance,
HED is taking into account this conservative exposure assessment. The
existing buprofezin tolerances (published, pending, and section 18
tolerances) include anticipated residues for citrus commodities, and
thus result in an Anticipated Residue Contribution (ARC) that is
equivalent to the following percentages of the RfD:
------------------------------------------------------------------------
Population subgroup %RfD
------------------------------------------------------------------------
U.S. Population (48 States)................................ 23.1%
U.S. Population - Summer Season............................ 26.0%
Nursing Infants (<1 year="" old)..............................="" 12.4%="" non-nursing="" infants=""><1 year="" old)..........................="" 47.4%="" children="" (1-6="" years="" old)...................................="" 48.2%="" children="" (7-12="" years="" old)..................................="" 34.6%="" northeast="" region...........................................="" 24.7%="" north="" central="" region.......................................="" 23.2%="" western="" region.............................................="" 25.4%="" hispanics..................................................="" 25.4%="" non-hispanic="" whites........................................="" 23.7%="" non-hispanic="" others........................................="" 23.3%="" males="" (13-19="" years="" old)....................................="" 23.5%="" ------------------------------------------------------------------------="" the="" subgroups="" listed="" above="" are:="" (1)="" the="" u.s.="" population="" (48="" states);="" (2)="" those="" for="" infants="" and="" children;="" and,="" (3)="" the="" other="" subgroups="" for="" which="" the="" percentage="" of="" the="" rfd="" occupied="" is="" greater="" than="" that="" occupied="" by="" the="" subgroup="" u.s.="" population="" (48="" states).="" 2.="" from="" drinking="" water.="" a="" tier="" i="" drinking="" water="" assessment="" of="" buprofezin="" was="" conducted.="" this="" assessment="" utilized="" geneec="" and="" sci-grow="" screening="" models="" to="" provide="" estimates="" of="" surface="" and="" ground="" water="" contamination="" resulting="" from="" applications="" of="" buprofezin.="" the="" estimated="" environmental="" concentrations="" (eecs)="" using="" the="" geneec="" model="" ranged="" from="" a="" peak="" concentration="" of="" 2.82="" parts="" per="" billion="" (ppb)="" to="" a="" 21-day="" average="" of="" 1.31="" ppb="" for="" aerial="" application.="" for="" calculation="" of="" chronic="" dwlocs,="" the="" higher="" 21-day="" average="" value="" (i.e.,="" aerial)="" was="" used.="" based="" on="" these="" screening="" models,="" maximum="" concentrations="" are="" not="" expected="" to="" exceed="" 3="" ppb="" in="" surface="" water="" and="" 0.013="" ppb="" in="" ground="" water.="" there="" are="" no="" established="" maximum="" contaminant="" level="" for="" residues="" of="" buprofezin="" in="" drinking="" water.="" no="" health="" advisory="" levels="" for="" buprofezin="" in="" drinking="" water="" have="" been="" established.="" acute="" and="" chronic="" exposure="" and="" risk.="" the="" ``interim="" guidance="" for="" conducting="" drinking="" water="" exposure="" and="" risk="" assessments''="" issued="" on="" 24-="" nov-1997="" using="" the="" geneec="" and="" the="" sci-grow="" models="" was="" used="" to="" produce="" estimates="" of="" buprofezin="" concentrations="" in="" surface="" and="" ground="" water="" respectively.="" the="" primary="" use="" of="" these="" models="" is="" to="" provide="" a="" coarse="" screen="" for="" sorting="" out="" pesticides="" for="" which="" opp="" has="" a="" high="" degree="" of="" confidence="" that="" the="" true="" levels="" of="" the="" pesticide="" in="" drinking="" water="" will="" be="" less="" than="" the="" human="" health="" drinking="" water="" levels="" of="" concern="" (dwlocs).="" the="" dwloc="" is="" an="" upper="" limit="" above="" which="" residues="" in="" drinking="" water="" would="" result="" in="" an="" unacceptable="" aggregate="" risk.="" the="">acute is the concentration in drinking water as
part of the acute aggregate exposure that occupies no more than 100% of
the RfD acute. The DWLOCchronic is the
concentration in drinking water as part of the aggregate chronic
exposure that occupies no more than 100% of the RfDchronic.
The Agency's default body weights and consumption values used to
calculate DWLOCs are as follows: 70 kg/2L (adult male), 60 kg/2L (adult
female), and 10 kg/1L (child).
For chronic (non-cancer) exposure to buprofezin in surface and
ground water, the drinking water levels of concern are 23,000
g/L for the U.S. Population, 19800 for females (13+ years),
and 6,400 g/L for children (1-6 yrs). To calculate the DWLOC
for acute exposure relative to a acute toxicity endpoint, the acute
dietary food exposure (from DRES) was subtracted from the acute RfD to
obtain the acceptable acute exposure to buprofezin in drinking water.
To calculate the DWLOC for chronic (non-cancer) exposure relative to a
chronic toxicity endpoint, the chronic dietary food exposure (from
DRES) was subtracted from the chronic RfD to obtain the acceptable
chronic (non-cancer) exposure to buprofezin in drinking water. DWLOCs
were then calculated using default body weights and drinking
consumption figures.
Estimated average concentrations of buprofezin in surface and
ground water are 0.013 ppb and 1.31 ppb, respectively. The estimated
average concentrations of buprofezin in surface and ground water are
less than OPP's level of concern for buprofezin in drinking water as a
contribution to chronic aggregate exposure. Therefore, taking into
account present uses and uses proposed in this action, OPP concludes
with reasonable certainty that residues of buprofezin in drinking water
(when considered along with other sources of exposure for which OPP has
reliable data) would not result in unacceptable levels of aggregate
human health risk at this time.
3. From non-dietary exposure. Buprofezin is an unregistered active
ingredient. Section 18 emergency exemptions have been approved for use
on cotton, citrus, and tomatoes. An experimental use permit (EUP) has
been granted for use on greenhouse ornamental plants. There are no
registered residential uses for this chemical.
4. Cumulative exposure to substances with common mechanism of
toxicity. Section 408(b)(2)(D)(v) requires that, when considering
whether to establish, modify, or revoke a tolerance, the Agency
consider ``available information'' concerning the cumulative effects of
a particular pesticide's residues and ``other substances that have a
common mechanism of toxicity.'' The Agency believes that ``available
information'' in this context might include not only toxicity,
chemistry, and exposure data, but also scientific policies and
methodologies for understanding common mechanisms of toxicity and
conducting cumulative risk assessments. For most pesticides, although
the Agency has some information in its files that may turn out to be
helpful in eventually determining whether a pesticide shares a common
mechanism of toxicity with any other substances, EPA does not at this
time have the methodologies to resolve the complex scientific issues
concerning common mechanism of toxicity in a meaningful way. EPA has
begun a pilot process to study this issue further through the
examination of particular classes of pesticides. The Agency hopes that
the results of this pilot process will increase the Agency's scientific
understanding of this question such that EPA will be able to develop
and apply scientific principles for better determining which chemicals
have a common mechanism of toxicity and evaluating the cumulative
effects of such chemicals. The Agency anticipates, however, that even
as its understanding of the science of common mechanisms increases,
decisions on specific classes of chemicals will be heavily dependent on
chemical specific data, much of which may not be presently available.
Although at present the Agency does not know how to apply the
information in its files concerning common mechanism issues to most
risk assessments, there are pesticides as to which the common mechanism
issues can be resolved. These pesticides include pesticides that are
toxicologically dissimilar to existing chemical substances (in which
case the Agency can conclude that it is unlikely
[[Page 41725]]
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 buprofezin 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,
buprofezin 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 buprofezin 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 subpopulation group of concern, females 13+
years, the acute dietary exposure to buprofezin from food will utilize
1.5 % of the acute RfD (calculated MOE is 20,000). The maximum
concentrations of buprofezin in surface and ground water are less than
OPP's levels of concern for buprofezin in surface and ground water as a
contribution to acute aggregate risk. Therefore, the aggregate acute
risk (food + water) is not expected to exceed the Agency's level of
concern for acute dietary exposure.
2. Chronic risk. Using the ARC exposure assumptions described
above, EPA has concluded that aggregate exposure to buprofezin from
food will utilize 23.1% of the RfD for the U.S. population. The major
identifiable subgroup with the highest aggregate exposure is 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 buprofezin 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 buprofezin 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. There are no registered residential uses for
buprofezin, therefore, the potential short and intermediate-term
aggregate risks are adequately addressed by the chronic aggregate
dietary (food + water) assessment.
D. Aggregate Cancer Risk for U.S. Population
Based on the buprofezin Q2*, the dietary cancer risk for
the U.S. population is 2.7 x 10 -7.
E. Aggregate Risks and Determination of Safety for Infants and Children
1. Safety factor for infants and children-- i. In general. In
assessing the potential for additional sensitivity of infants and
children to residues of buprofezin, EPA considered data from
developmental toxicity studies in the rat and rabbit and a 2-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 10-
fold margin of safety for infants and children in the case of threshold
effects to account for pre-and post-natal toxicity and the completeness
of the data base 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. In
either case, EPA generally defines the level of appreciable risk as
exposure that is greater than 1/100 of the no observed effect level in
the animal study appropriate to the particular risk assessment. This
100-fold uncertainty (safety) factor/MOE (safety) is designed to
account for inter-species extrapolation and intra-species variability.
HED believes that reliable data support using the 100-fold margin/
factor, rather than the 1,000-fold margin/factor, when EPA has a
complete data base under existing guidelines, and when the severity of
the effect in infants or children, the potency or unusual toxic
properties of a compound, or the quality of the exposure data do not
raise concerns regarding the adequacy of the standard margin/factor.
ii. Developmental toxicity studies. In a developmental study in
rats, the maternal (systemic) NOEL was 200 mg/kg/day, based on
mortality, decreased pregnancy rates, and increased resorptions at the
LOEL of 800 mg/kg/day. The developmental (fetal) NOEL was 200 mg/kg/
day, based on increased incidence of delayed ossifications and
decreased pup weight at the LOEL of 800 mg/kg/day.
In a developmental toxicity study in rabbits, the maternal
(systemic) NOEL was 50 mg/kg/day, based on body weight and food
consumption and possibly increased fetal loss at the LOEL of 250 mg/kg/
day. The developmental (pup) NOEL was 250 mg/kg/day (highest dose
tested).
iii. Reproductive toxicity study. The 2-generation reproductive
toxicity in rats does not satisfy guideline requirements for a
reproduction study and is considered a data gap.
iv. Pre- and post-natal sensitivity. The toxicological data base
for evaluating pre- and post-natal toxicity for buprofezin is not
complete with respect to current data requirements, since there is no
adequate reproduction study. There are no pre- or post-natal toxicity
concerns for infants and children, based on the results of the rat and
rabbit developmental toxicity studies, but the Agency recommends an
additional FQPA factor of 3 due to the absence of the reproduction
study and the possible incomplete assessment of extra-sensitivity to
infants and children.
v. Conclusion. Based on the above, the Agency concludes that
reliable data support use of a 300-fold margin of exposure/uncertainty
factor, rather than the standard 1,000-fold margin/factor, to protect
infants and children for acute dietary MOE requirements and the
determination of the RfD.
2. Acute risk. For females 13+ years, the acute dietary exposure
(maternal and fetal) to buprofezin from food will utilize 1.5% of the
acute RfD (calculated MOE is 20,000). These calculations are based on a
developmental NOEL in rats of 200 mg/kg/day. This risk assessment
assumed 100% crop treated with tolerance level residues on all treated
crops consumed, resulting in a significant overestimate of dietary
exposure. The maximum concentrations of buprofezin in surface and
ground water are less than OPP's levels of concern for buprofezin in
surface and ground water as a contribution to acute aggregate risk.
Therefore, the aggregate acute risk (food + water) is not expected to
exceed OPP's level of concern for acute dietary exposure.
3. Chronic risk. Using the conservative exposure assumptions
described above, EPA has concluded that aggregate exposure to
buprofezin from food ranges from 12.4% of the RfD
[[Page 41726]]
for nursing infants less than 1 years old, up to 48.2% of the RfD for
children 1-6 years old. EPA generally has no concern for exposures
below 100% of the RfD because the RfD represents the level at or below
which daily aggregate dietary exposure over a lifetime will not pose
appreciable risks to human health. The estimated average concentrations
of buprofezin in surface and ground water are less than OPP's levels of
concern for buprofezin in surface and ground water as a contribution to
chronic aggregate risk. Under current HED guidelines, the non-dietary
uses of buprofezin do not constitute a chronic exposure scenario.
4. Short- or intermediate-term risk. Short- and intermediate-term
aggregate exposure takes into account chronic dietary food and water
(considered to be a background exposure level) plus indoor and outdoor
residential uses. There are no registered residential uses for
buprofezin, therefore the potential short and intermediate-term
aggregate risks are adequately addressed by the chronic aggregate
dietary (food + water) risk assessment.
V. Other Considerations
A. Metabolism In Plants and Animals
The nature of the residue in plants is adequately understood for
purposes of this section 18 only. Studies conducted in tomatoes,
lettuce, cotton, and citrus indicate that the residue of concern is the
parent buprofezin (BF1, 2-tert-butylimino-3-isopropyl-5-phenylperhydro-
1,3,5-thiadizinan-4-one) only. The nature of the residue in animals
(rats and fish) is consistent with that determined for crops.
B. Analytical Enforcement Methodology
Adequate enforcement methodology (gas chromatography using a
nitrogen-phosphorous detector) is available to enforce the proposed
tolerance on cucurbits and tomatoes. The method was validated by an
independent laboratory using lettuce, tomato, and cucumber as the test
matrices. Samples of the test matrices were fortified with buprofezin
at 0.1 ppm, 0.5 ppm, and 1.0 ppm. Recoveries were reported as 90%, 94%,
and 82% for lettuce, tomato, and cucumber respectively. In addition,
methodology for buprofezin and its metabolites in cottonseed and gin
trash is summarized in the report ``Determination of Buprofezin and BF
12 residues in Cottonseed and Gin Trash,'' Method BF-96-01, AgrEvo
Corporation, Wilmington, Delaware. The limit of detection for
buprofezin is 0.01 ppm and the limit of quantitation is 0.02 ppm.
C. Magnitude of Residues
Residues of buprofezin are not expected to exceed 0.5 ppm in/on
cucurbits or 0.7 ppm in/on tomatoes and 1.0 ppm in tomato paste as a
result of these section 18 uses.
D. International Residue Limits
A temporary Codex MRL of 1.0 mg/kg has been established for
buprofezin on tomatoes (pending additional data submission). There are
no Canadian or Mexican MRLs for buprofezin on tomatoes. Therefore,
compatibility problems may exist (i.e., the Codex MRL is higher than
the U.S. tolerance) which will need to be addressed when a permanent
section 3 tolerance for buprofezin on tomatoes is granted.
E. Rotational Crop Restrictions
The following plant-back restrictions are required: - 30 days for
brassica and non-brassica leafy vegetables, small grains, and radishes
- 120 days for all other crops.
VI. Conclusion
Therefore, the tolerance is established for residues of buprofezin
in cucurbits at 0.5 ppm, tomatoes at 0.7 ppm, and tomato paste at 1.0
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 October 5, 1998, file written objections to any
aspect of this regulation and may also request a hearing on those
objections. Objections and hearing requests must be filed with the
Hearing Clerk, at the address given above (40 CFR 178.20). A copy of
the objections and/or hearing requests filed with the Hearing Clerk
should be submitted to the OPP docket for this rulemaking. The
objections submitted must specify the provisions of the regulation
deemed objectionable and the grounds for the objections (40 CFR
178.25). Each objection must be accompanied by the fee prescribed by 40
CFR 180.33(i). If a hearing is requested, the objections must include a
statement of the factual issues on which a hearing is requested, the
requestor's contentions on such issues, and a summary of any evidence
relied upon by the requestor (40 CFR 178.27). A request for a hearing
will be granted if the Administrator determines that the material
submitted shows the following: There is genuine and substantial issue
of fact; there is a reasonable possibility that available evidence
identified by the requestor would, if established, resolve one or more
of such issues in favor of the requestor, taking into account
uncontested claims or facts to the contrary; and resolution of the
factual issues in the manner sought by the requestor would be adequate
to justify the action requested (40 CFR 178.32). Information submitted
in connection with an objection or hearing request may be claimed
confidential by marking any part or all of that information as CBI.
Information so marked will not be disclosed except in accordance with
procedures set forth in 40 CFR part 2. A copy of the information that
does not contain CBI must be submitted for inclusion in the public
record. Information not marked confidential may be disclosed publicly
by EPA without prior notice.
VIII. Public Record and Electronic Submissions
EPA has established a record for this rulemaking under docket
control number [OPP-300689] (including any comments and data submitted
electronically). A public version of this record, including printed,
paper versions of electronic comments, which does not include any
information claimed as CBI, is available for inspection from 8:30 a.m.
to 4 p.m., Monday through Friday, excluding legal holidays. The public
record is located in Room 119 of the Public Information and Records
Integrity Branch, Information Resources and Services Division (7502C),
Office of Pesticide Programs, Environmental Protection Agency, Crystal
Mall #2, 1921 Jefferson Davis 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
[[Page 41727]]
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 tolerances under FFDCA section
408(l)(6). The Office of Management and Budget (OMB) has exempted these
types of actions from review under Executive Order 12866, entitled
Regulatory Planning and Review (58 FR 51735, October 4, 1993). This
final rule does not contain any information collections subject to OMB
approval under the Paperwork Reduction Act (PRA), 44 U.S.C. 3501 et
seq., or impose any enforceable duty or contain any unfunded mandate as
described under Title II of the Unfunded Mandates Reform Act of 1995
(UMRA) (Pub. L. 104-4). Nor does it require any prior consultation as
specified by Executive Order 12875, entitled Enhancing the
Intergovernmental Partnership (58 FR 58093, October 28, 1993), or
special considerations as required by Executive Order 12898, entitled
Federal Actions to Address Environmental Justice in Minority
Populations and Low-Income Populations (59 FR 7629, February 16, 1994),
or require OMB review in accordance with Executive Order 13045,
entitled Protection of Children from Environmental Health Risks and
Safety Risks (62 FR 19885, April 23, 1997).
In addition, since these tolerances and exemptions that are
established under FFDCA section 408 (l)(6), such as the tolerances in
this final rule, do not require the issuance of a proposed rule, the
requirements of the Regulatory Flexibility Act (RFA) (5 U.S.C. 601 et
seq.) do not apply. Nevertheless, the Agency has previously assessed
whether establishing tolerances, exemptions from tolerances, raising
tolerance levels or expanding exemptions might adversely impact small
entities and concluded, as a generic matter, that there is no adverse
economic impact. The factual basis for the Agency's generic
certification for tolerance acations 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 Comptroller General
The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the
Small Business Regulatory Enforcement Fairness Act of 1996, generally
provides that before a rule may take effect, the agency promulgating
the rule must submit a rule report, which includes a copy of the rule,
to each House of the Congress and to the Comptroller General of the
United States. EPA will submit a report containing this rule and other
required information to the U.S. Senate, the U.S. House of
Representatives, and the Comptroller General of the United States prior
to publication of the rule in the Federal Register. This rule is not a
``major rule'' as defined by 5 U.S.C. 804(2).
List of Subjects in 40 CFR Part 180
Environmental protection, Administrative practice and procedure,
Agricultural commodities, Pesticides and pests, Reporting and
recordkeeping requirements.
Dated: July 16, 1998.
James Jones,
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 180.511 is amending paragraph (b) by alphabetically
adding the following entries to the table to read as follows:
Sec. 180.511 Buprofezin; tolerances for residues
* * * * *
(b) * * *
------------------------------------------------------------------------
Expiration/
Commodity Parts per Revocation
million Date
------------------------------------------------------------------------
* * * * *
Cucurbits..................................... 0.5 12/31/99
* * * * *
Tomatoes...................................... 0.7 12/31/99
Tomato paste.................................. 1.0 12/31/99
------------------------------------------------------------------------
* * * * *
[FR Doc. 98-20906 Filed 8-4-98; 8:45 am]
BILLING CODE 6560-50-F
