[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: [email protected]. Copies of objections and 
hearing requests must be submitted as an ASCII file avoiding the use of 
special characters and any form of encryption. Copies of objections and 
hearing requests will also be accepted on disks in WordPerfect 5.1/6.1 
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: 
[email protected].
SUPPLEMENTARY INFORMATION: EPA, on its own initiative, pursuant to 
section 408(e) and (l)(6) of the Federal Food, Drug, and Cosmetic Act 
(FFDCA), 21 U.S.C. 346a(e) and (l)(6), is establishing tolerances for 
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 DWLOCacute 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:
    [email protected].


    Electronic comments must be submitted as an ASCII file avoiding the 
use of special characters and any form of encryption.
    The official record for this rulemaking, as well as the public 
version, as described above will be kept in paper form. Accordingly, 
EPA will transfer any copies of objections and hearing requests 
received electronically

[[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