[Federal Register Volume 62, Number 80 (Friday, April 25, 1997)]
[Rules and Regulations]
[Pages 20104-20111]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-10724]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[OPP-300478; FRL-5713-1]
RIN 2070-AB78


Oxyfluorfen; Pesticide Tolerance for Emergency Exemption

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This regulation establishes a time-limited tolerance for 
residues of the herbicide Oxyfluorfen in or on the food commodity 
strawberry in connection with EPA's granting of emergency exemptions 
under the Federal Insecticide, Fungicide, and Rodenticide Act 
authorizing use of Oxyfluorfen on strawberries in Massachusetts, New 
Hampshire, Connecticut, Maine, Washington and Oregon. This regulation 
establishes maximum permissible levels for residues of Oxyfluorfen in 
this food pursuant to the Federal Food, Drug, and Cosmetic Act, as 
amended by the Food Quality Protection Act of 1996. The tolerance will 
expire and is revoked on April 15, 1998.
DATES: This regulation becomes effective April 25, 1997. Objections and 
requests for hearings must be received by EPA on or before June 24, 
1997.

ADDRESSES: Written objections and hearing requests, identified by the 
docket control number, [OPP-300478], 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

[[Page 20105]]

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-300478], must also 
be submitted to: Public Response and Program Resources Branch, Field 
Operations Division (7506C), Office of Pesticide Programs, 
Environmental Protection Agency, 401 M St., SW., Washington, DC 20460. 
In person, bring a copy of objections and hearing requests to Rm. 1132, 
CM #2, 1921 Jefferson Davis Highway, 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]. Such copies of objections and 
hearing requests must be submitted as an ASCII file avoiding the use of 
special characters and any form of encryption. Copies of objections and 
hearing requests will also be accepted on disks in WordPerfect 5.1 file 
format or ASCII file format. All copies of objections and hearing 
requests in electronic form must be identified by the docket number 
[OPP-300478]. No Confidential Business Information (CBI) should be 
submitted through e-mail. Electronic copies of objections and hearing 
requests on this rule may be filed online at many Federal Depository 
Libraries.

FOR FURTHER INFORMATION CONTACT: By mail: Pat Cimino, Registration 
Division (7505W), Environmental Protection Agency, 401 M St., SW., 
Washington, DC 20460. Office location, telephone number, and e-mail: 
Sixth Floor, Crystal Station #1, 2800 Jefferson Davis Highway, 
Arlington, VA, (703) 308-8328, e-mail: [email protected].
SUPPLEMENTARY INFORMATION: EPA, pursuant to section 408(e) and (l)(6) 
of the Federal Food, Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 346a(e) 
and (l)(6), is establishing a tolerance for residues of the herbicide 
oxyfluorfen, [2-chloro-1-(3-ethoxy-4-nitrophenoxy)-4-
(trifluoromethyl)benzene] in or on strawberries, at 0.05 part per 
million (ppm). The residue requiring regulation is parent oxyfluorfen 
only. This tolerance will expire and be revoked by EPA on April 15, 
1998. After April 15, 1998, EPA will publish a document in the Federal 
Register to remove the revoked tolerances from the Code of Federal 
Regulations.

I. Background and Statutory Authority

    The Food Quality Protection Act of 1996 (FQPA) (Pub. L. 104-170) 
was signed into law August 3, 1996. FQPA amends both the Federal Food, 
Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 301 et seq., and the Federal 
Insecticide, Fungicide, and Rodenticide Act (FIFRA), 7 U.S.C. 136 et 
seq. The FQPA amendments went into effect immediately. Among other 
things, FQPA amends FFDCA to bring all EPA pesticide tolerance-setting 
activities under a new section 408 with a new safety standard and new 
procedures. These activities are described below and discussed in 
greater detail in the final rule establishing the time-limited 
tolerance associated with the emergency exemption for use of 
propiconazole on sorghum (61 CFR 58135, November 13, 1996) (FRL-5572-
9).
    New section 408(b)(2)(A)(i) 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, 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) 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. Section 408(l)(6) also requires EPA to promulgate regulations 
by August 3, 1997, governing the establishment of tolerances and 
exemptions under section 408(l)(6) and requires that the regulations be 
consistent with section 408(b)(2) and (c)(2) and FIFRA section 18.
    Section 408(l)(6) allows EPA to establish tolerances or exemptions 
from the requirement for a tolerance, in connection with EPA's granting 
of FIFRA section 18 emergency exemptions, without providing notice or a 
period for public comment. Thus, consistent with the need to act 
expeditiously on requests for emergency exemptions under FIFRA, EPA can 
establish such tolerances or exemptions under the authority of section 
408(e) and (l)(6) without notice and comment rulemaking.
    In establishing section 18-related tolerances and exemptions during 
this interim period before EPA issues the section 408(l)(6) procedural 
regulation and before EPA makes its broad policy decisions concerning 
the interpretation and implementation of the new section 408, EPA does 
not intend to set precedents for the application of section 408 and the 
new safety standard to other tolerances and exemptions. Rather, these 
early section 18 tolerance and exemption decisions will be made on a 
case-by-case basis and will not bind EPA as it proceeds with further 
rulemaking and policy development. EPA intends to act on section 18-
related tolerances and exemptions that clearly qualify under the new 
law.

II. Emergency Exemption for Oxyfluorfen on Strawberries and FFDCA 
Tolerances

    The Massachusetts Department of Food and Agriculture; Maine 
Department of Agriculture, Food and Rural Resources; Connecticut 
Department of Environmental Protection; and New Hampshire, Oregon and 
Washington Departments of Agriculture requested specific exemptions 
under FIFRA section 18 for the use of oxyfluorfen on strawberries to 
control wood sorrel (Oxalis sp.), and field pansy (Viola tricolor) in 
Massachusetts, Maine, Connecticut and New Hampshire and common 
groundsel (Senecia vulgaris), common lambsquarter (Chenopodium album), 
redroot pigweed (Amaranthus retroflexus), prostate knotweed, (Polygonum 
aviculare), smartweed (Polygonum persicaria), corn spurry (Spergula 
arvensis), wild buckwheat (Polygonum convolvulus), mayweed (Anthemis 
cotula), and pineappleweed (Capsella bursa-pastoris) in Oregon and 
Washington. The states indicated that an emergency situation is present 
due to lack of registered, effective alternatives to control these 
broadleaf weeds. The voluntary cancellations of chloroxuron (Tenoran) 
and dipenamid (Enide), depletion of the existing stocks of these 
materials, and recent label changes, varietal sensitivity and plant-
back restrictions for terbacil (Sinbar) have resulted in a lack of 
effective materials

[[Page 20106]]

for control of the above weeds. The states indicate that they will 
suffer significant losses without an effective control for these weeds. 
After reviewing the applicants' submissions, the Agency concurs that 
emergency conditions exist for these states.
    As part of its assessment of these crisis declarations, EPA 
assessed the potential risks presented by residues of oxyfluorfen in or 
on strawberries. In doing so, EPA considered the new safety standard in 
FFDCA section 408(b)(2), and EPA decided to grant the section 18 
exemptions only after concluding that the necessary tolerance under 
FFDCA section 408(l)(6) would clearly be consistent with the new safety 
standard and with FIFRA section 18. This tolerance for oxyfluorfen will 
permit the marketing of strawberries treated in accordance with the 
provisions of the section 18 emergency exemptions. Consistent with the 
need to move quickly on the emergency exemptions and to ensure that the 
resulting food is safe and lawful, EPA is issuing this tolerance 
without notice and opportunity for public comment under section 408(e) 
as provided for in section 408(l)(6). Although this tolerance will 
expire and is revoked on April 15, 1998, under FFDCA section 408(l)(5), 
residues of oxyfluorfen not in excess of the amount specified in the 
tolerance remaining in or on strawberries after that date will not be 
unlawful, provided the pesticide is applied during the term of, and in 
accordance with all the conditions of, section 18 of FIFRA. EPA will 
take action to revoke this tolerance earlier if any experience with, 
scientific data on, or other relevant information on this pesticide 
indicate that the residues are not safe.
    EPA has not made any decisions about whether oxyfluorfen meets the 
requirements for registration under FIFRA section 3 for use on 
strawberries, or whether a permanent tolerance for oxyfluorfen in or on 
strawberries would be appropriate. This action by EPA does not serve as 
a basis for registration of oxyfluorfen by a State for special local 
needs under FIFRA section 24(c). Nor does this action serve as the 
basis for any State other than Massachusetts, Maine, New Hampshire, 
Connecticut, Oregon and Washington to use this product on this crop 
under section 18 of FIFRA without following all provisions of section 
18 as identified in 40 CFR part 166. For additional information 
regarding the emergency exemptions for oxyfluorfen, 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. For many 
of these studies, a dose-response relationship can be determined, which 
provides a dose that causes adverse effects (threshold effects) and 
doses causing no observed effects (the ``no-observed effect level'' or 
``NOEL'').
    Once a study has been evaluated and the observed effects have been 
determined to be threshold effects, EPA generally divides the NOEL from 
the study with the lowest NOEL by an uncertainty factor (usually 100 or 
more) to determine the Reference Dose (RfD). The RfD is a level at or 
below which daily aggregate exposure over a lifetime will not pose 
appreciable risks to human health. An uncertainty factor (sometimes 
called a ``safety factor'') of 100 is commonly used since it is assumed 
that people may be up to 10 times more sensitive to pesticides than the 
test animals, and that one person or subgroup of the population (such 
as infants and children) could be up to 10 times more sensitive to a 
pesticide than another. In addition, EPA assesses the potential risks 
to infants and children based on the weight of the evidence of the 
toxicology studies and determines whether an additional uncertainty 
factor is warranted. Thus, an aggregate daily exposure to a pesticide 
residue at or below the RfD (expressed as 100 percent or less of the 
RfD) is generally considered by EPA to pose a reasonable certainty of 
no harm.
    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 
relationships. Once a pesticide has been classified as a potential 
human carcinogen, different types of risk assessments [e.g., linear 
low-dose extrapolations or margin of exposure (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.
    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, and other non-
occupational exposures, such as where residues leach into groundwater 
or surface water that is consumed as drinking water. 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. 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 percent 
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.

IV. Aggregate Risk Assessments, Cumulative Risk Discussion, 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. Oxyfluorfen is registered by EPA for outdoor residential 
uses.
    Tolerances have been established (40 CFR 180.381) for the combined 
residues of oxyfluorfen, [2-chloro-1-(3-ethoxy-4-nitrophenoxy)-4-
(trifluoromethyl)benzene] and its metabolites containing the diphenyl 
ether linkage expressed in or on certain food commodities ranging from 
0.05 ppm in stone fruits to 0.25 ppm in mint oil. There are no 
livestock feed items associated with these section 18 requests and 
secondary residues are not expected to occur in meat, milk, poultry or 
eggs as a result of these section 18 uses. Based on information 
submitted to the Agency, EPA has sufficient data to assess the hazards 
of oxyfluorfen and to

[[Page 20107]]

make a determination on aggregate exposure, consistent with section 
408(b)(2), for the time-limited tolerance for residues of oxyfluorfen 
on strawberries at 0.05 ppm. EPA's assessment of the dietary exposures 
and risks associated with establishing this tolerance follows.

A. Toxicological Profile

    1. Acute risk. For the acute dietary risk assessment, the Agency 
recommended use of the NOEL of 10 mg/kg/day, based on fused sternebrae 
observed in pups at the Lowest Effect Level (LEL) of 30 mg/kg/day, from 
the developmental toxicity study in rabbits. This NOEL is used to 
evaluate the Margin of Exposure (MOE) from the acute dietary risk to 
pregnant women 13+ years or older.
    2. Chronic risk. The RfD of 0.003 mg/kg/day was established by the 
Agency on April 14, 1986, based on a 20-month feeding study in mice 
with a NOEL of 0.3 mg/kg/day and an uncertainty factor of 100. The 
effects observed at the LEL of 3.0 mg/kg/day were necrosis, 
hyperplastic nodules, and absolute liver weight.
    3. Cancer risk. Oxyfluorfen has been classified as a Group C 
chemical by the Agency based on liver adenomas and carcinomas in the 
20-month feeding study in mice. The Agency recommended using the 
Q1* approach to assess cancer risk. The Q1* is 0.128 (mg/kg/
day)-1.
    4. Developmental toxicity risk. From the developmental toxicity 
study in rats, the maternal NOEL was 18 mg/kg/day and the maternal LEL 
was 183 mg/kg/day, based on decreased weight gain and food consumption, 
increased incidences of soft or scant feces, increased alkaline 
phosphatase and SGOT and mortality at high-dose. The developmental 
(pup) NOEL was 18 mg/kg/day and the developmental LEL was 183 mg/kg/day 
based on decreased fetal body weight, increased resorptions, and an 
increase in the incidences of left carotid artery arising from the 
innominate, bent bones of the forelimbs, and other ossification 
irregularities; these effects were confined to the mid-dose level, 
since there was 100% litter loss in the high-dose group [848 mg/kg/day] 
as the result of maternal mortality and resorptions. From the 
developmental toxicity study in rabbits, the maternal (systemic) NOEL 
was 10 mg/kg/day and the maternal LEL was 30 mg/kg/day based on 
anorexia and decreased body weight gain. The developmental (pup) NOEL 
was 10 mg/kg/day and the developmental LEL was 30 mg/kg/day based on 
fused sternebrae.
    5. Reproductive toxicity risk. In the 2-generation reproduction 
study in rats, the reproductive (pup) NOEL was 400 ppm [20 mg/kg/day] 
and the reproductive LEL was 1,600 ppm [80 mg/kg/day] based on 
decreased pup body weight during lactation in both the F1a and F2a 
litters and also a decreased litter size at birth in F1a and F2a 
litters. The systemic (parents) NOEL was 400 ppm and LEL was 1,600 ppm 
based on pelvic mineralization of P1 males, P2 males and females, and 
pelvic papillary hyperplasia in P1 and P2 males and P2 females. Also at 
1,600 ppm, there were additional kidney effects, consisting of 
dilatation of collecting ductules in both P2 sexes. Other high-dose 
histological findings consisted of hepatocellular hypertrophy in both 
sexes of P1 and P2 animals. Additional high-dose effects were alopecia 
in both sexes of P1 and P2 animals during growth, and decreased weight 
gain during growth and gestation of P1 and P2 parental animals.

B. Aggregate Exposure

    In examining aggregate exposure, FQPA directs EPA to consider 
available information concerning exposures from the pesticide residue 
in food and all other non-occupational exposures. The primary non-food 
sources of exposure the Agency looks at include drinking water (whether 
from groundwater or surface water), and exposure through pesticide use 
in gardens, lawns, or buildings (residential and other indoor uses).
    Permanent oxyfluorfen food tolerances have been established and 
there are no livestock feed items associated with these section 18 
requests. Oxyfluorfen is registered for outdoor residential uses.
    1. Chronic exposure-- i. Dietary risk assessment considerations. In 
conducting exposure assessments for these section 18 requests, EPA 
partially refined the chronic RfD and cancer risk assessments by using 
a combination of the TMRC (worst-case) and dietary exposure assumptions 
based on anticipated residues and/or percent of crop treated. Percent 
of crop treated estimates are derived from reliable 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 crop treated, the Agency is 
reasonably certain that exposure is not understated for any significant 
subpopulation group. In addition, actual residues are expected to be 
quite low because the majority of the use patterns direct sprays onto 
weeds and away from the crop and there are long pre-harvest intervals 
for sprays which are directly applied to crops.
    To determine chronic (using the RfD) and cancer (using the Q1* 
approach) risks, the Agency has utilized the TMRC to estimate dietary 
exposure from proposed uses of oxyfluorfen on strawberries and peanuts, 
and from registered uses of oxyfluorfen with tolerances established for 
the following food items: dates, figs, guava, loquats, olives and olive 
oil, papaya, persimmon, pomegranate, plantains, kiwi, cocoa butter, 
coffee, artichokes, taro-roots and greens, garlic, shallots, 
cauliflower, bok-choy and other chinese variety cole crops, dry beans, 
crabapples, quince, blackberry, raspberry, brazil nut, cashew, 
chestnuts, hazelnuts, hickory nuts, macadamias, pecans, horseradish and 
peppermint and spearmint oils. The TMRC is obtained by multiplying the 
tolerance level residue for these foods by the average consumption data 
(estimates of the amount of the foods eaten by various population 
subgroups). The risk assessment using TMRC assumptions is considered to 
be overestimated.
    Refined dietary exposure estimates using percent of crop treated 
were used to assess chronic dietary risk for registered uses of 
oxyfluorfen with established tolerances for the following foods and/or 
animal feed items: pistachio nuts, cottonseed meal, cherries, 
nectarines, plums, prunes, almonds and walnuts. Refined dietary 
exposure estimates using anticipated residues were used to assess 
chronic dietary risk for registered uses of oxyfluorfen with 
established tolerances on the following food items: bananas, broccoli, 
cabbage, apricots, meat and milk. Refined dietary exposure estimates 
using percent of crop treated and anticipated residues were used to 
assess chronic dietary risk for registered uses of oxyfluorfen with 
established tolerances on the following food and/or animal feed items: 
cottonseed oil, onions, soybeans, soybean oil, apples, pears, peaches, 
grapes and corn.
    The Agency considers the partially refined estimates for chronic 
RfD and cancer risks to be conservative.
    ii. Drinking water considerations. The Agency has reviewed 
environmental fate data which indicate that oxyfluorfen is persistent 
but non-mobile. There is no established Maximum Concentration Level 
(MCL) for residues of oxyfluorfen in drinking water. No health advisory 
levels for oxyfluorfen in drinking water have been established. As 
noted in ``Pesticides in Groundwater Database'' EPA 734-12-92-001, Sept 
1992, 188 wells were

[[Page 20108]]

monitored in Texas in 1987 and 1988. No detectable residues of 
oxyfluorfen were found in any of the samples.
    Because the Agency lacks sufficient water-related exposure data to 
complete a comprehensive drinking water risk assessment for many 
pesticides, EPA has commenced and nearly completed a process to 
identify a reasonable yet conservative bounding figure for the 
potential contribution of water related exposure to the aggregate risk 
posed by a pesticide. In developing the bounding figure, EPA estimated 
residue levels in water for a number of specific pesticides using 
various data sources. The Agency then applied the estimated residue 
levels, in conjunction with appropriate toxicological endpoints (RfD's 
or acute dietary NOEL's) and assumptions about body weight and 
consumption, to calculate, for each pesticide, the increment of 
aggregate risk contributed by consumption of contaminated water. While 
EPA has not yet pinpointed the appropriate bounding figure for 
consumption of contaminated water, the ranges the Agency is continuing 
to examine are all below the level that would cause oxyfluorfen to 
exceed the RfD if the tolerance being considered in this document were 
granted. In addition, chronic exposure to oxyfluorfen residues 
resulting from potential water exposure would not increase the total 
cancer risk so that it exceeds the Agency's level of concern. The 
Agency has therefore concluded that the potential exposures associated 
with oxyfluorfen in water, even at the higher levels the Agency is 
considering as a conservative upper bound for RfD exposure 
considerations, would not prevent the Agency from determining that 
there is a reasonable certainty of no harm if the tolerance is granted.
    iii. Non-dietary, non-occupational considerations. Oxyfluorfen is 
registered for outdoor residential use. Acceptable, reliable data are 
not currently available with which to assess acute risk. However, based 
on the available residential exposure data and the best professional 
judgment of scientists who have worked with the available occupational 
exposure data, 5% of the risk for outdoor residential uses is a 
reasonable, protective default assumption for this pesticide. In the 
best scientific judgment of the Agency, chronic exposure to oxyfluorfen 
residues resulting from potential outdoor residential exposure would 
not increase the total chronic or cancer risks so that they exceed the 
Agency's level of concern.
    2. Acute exposure. 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 1 day or 
single exposure. Under FQPA, drinking water is also considered a 
component of the acute dietary exposure.
    Theoretically, it is also possible that a residential, or other 
non-dietary, exposure could be combined with the acute total dietary 
exposure from food and water. However, the Agency does not believe that 
aggregating multiple exposure to large amounts of pesticide residues in 
the residential environment via multiple products and routes for a 1-
day exposure is a reasonably probable event. It is highly unlikely 
that, in 1 day, an individual would have multiple high-end exposures to 
the same pesticide by treating their lawn and garden, treating their 
house via crack and crevice application, swimming in a pool, and be 
maximally exposed in the food and water consumed.
    The acute dietary exposure endpoint of concern for oxyfluorfen is 
fused sternebrae in developing pups which was observed in the rabbit 
developmental study. The population subgroup of concern is females 13+ 
years old (women of childbearing age). Acute dietary exposure (food 
only) was calculated using the TMRC (worst case) assumptions. An MOE of 
100 (food only) or greater is acceptable for these section 18 requests.
    Despite the potential for acute exposure to oxyfluorfen in drinking 
water, EPA does not expect the aggregate acute exposure to exceed the 
Agency's level of concern if the tolerance being considered in this 
document were granted. The Agency has therefore concluded that the 
potential acute term exposures associated with oxyfluorfen in water, 
even at the higher levels the Agency is considering as a conservative 
upper bound, would not prevent the Agency from determining that there 
is a reasonable certainty of no harm if the tolerance is granted.

C. Cumulative Exposure to Substances with Common Mechanism of Toxicity

    Section 408(b)(2)(D)(v) requires that, when considering whether to 
establish, modify, or revoke a tolerance, the Agency consider 
``available information'' concerning the cumulative effects of a 
particular pesticide's residues and ``other substances that have a 
common mechanism of toxicity.'' The Agency believes that ``available 
information'' in this context might include not only toxicity, 
chemistry, and exposure data, but also scientific policies and 
methodologies for understanding common mechanisms of toxicity and 
conducting cumulative risk assessments. For most pesticides, although 
the Agency has some information in its files that may turn out to be 
helpful in eventually determining whether a pesticide shares a common 
mechanism of toxicity with any other substances, EPA does not at this 
time have the methodologies to resolve the complex scientific issues 
concerning common mechanism of toxicity in a meaningful way. EPA has 
begun a pilot process to study this issue further through the 
examination of particular classes of pesticides. The Agency hopes that 
the results of this pilot process will increase the Agency's scientific 
understanding of this question such that EPA will be able to develop 
and apply scientific principles for better determining which chemicals 
have a common mechanism of toxicity and evaluating the cumulative 
effects of such chemicals. The Agency anticipates, however, that even 
as its understanding of the science of common mechanisms increases, 
decisions on specific classes of chemicals will be heavily dependent on 
chemical specific data, much of which may not be presently available.
    Although at present the Agency does not know how to apply the 
information in its files concerning common mechanism issues to most 
risk assessments, there are pesticides as to which the common mechanism 
issues can be resolved. These pesticides include pesticides that are 
toxicologically dissimilar to existing chemical substances (in which 
case the Agency can conclude that it is unlikely that a pesticide 
shares a common mechanism of activity with other substances) and 
pesticides that produce a common toxic metabolite (in which case common 
mechanism of activity will be assumed).
    EPA does not have, at this time, available data to determine 
whether oxyfluorfen 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, 
oxyfluorfen 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 oxyfluorfen has a common mechanism of toxicity 
with other substances.

D. Determination of Safety for U.S. Population

    1. Chronic RfD and cancer risk. Using the partially refined dietary 
exposure assumptions described above and taking

[[Page 20109]]

into account the completeness and reliability of the toxicity data, EPA 
has concluded that aggregate dietary exposure (food only) to 
oxyfluorfen will utilize <1% of the RfD for the U.S. population. EPA 
generally has no concern for exposures below 100 percent of the RfD 
because the RfD represents the level at or below which daily aggregate 
dietary exposure over a lifetime will not pose appreciable risks to 
human health. Despite the potential for exposure to oxyfluorfen in 
drinking water and from the 5% default-level contribution from non-
dietary, non-occupational exposure, EPA does not expect the aggregate 
exposure to exceed 100% of the RfD.
    As noted above, oxyfluorfen has been classified as a Group C 
chemical by the Agency based on liver adenomas and carcinomas in the 
20-month mouse feeding study. The Agency recommended using the Q1* 
approach to assess cancer risk, with a value of 0.128 (mg/kg/day)-
1. The partially refined dietary assumptions for existing oxyfluorfen 
tolerances plus amortized section 18 strawberry use (adjusted for a 6 
year duration of exposure to this section 18 use over a 70 year 
lifetime) result in a Anticipated Residue Contribution (ARC) that is 
equivalent to 1.8  x  10-6 (food only). Although this number is 
partially refined, it is still considered conservative by the Agency. 
Actual residues are expected to be quite low because the majority of 
the use patterns direct sprays onto weeds and away from the crop and 
there are long pre-harvest intervals for sprays which are directly 
applied to crops. Environmental fate data indicate that oxyfluorfen 
strongly adheres to soil, does not leach into groundwater and has not 
been detected in sampled groundwater. Based on this information, 
occurrence of oxyfluorfen in drinking water is unlikely. Outdoor 
residential uses of oxyfluorfen are limited and exposure is expected to 
be low. Oxyfluorfen is toxic to lawn grasses and certain ornamental 
plants, and use is generally limited to spot treatments for non-
selective weed control. In the best scientific judgment of the Agency, 
chronic exposure to oxyfluorfen residues resulting from potential 
residential and/or water exposure would not increase the total cancer 
risk so that it exceeds the Agency's level of concern. EPA concludes 
that there is a reasonable certainty that no harm will result from 
chronic aggregate exposure to oxyfluorfen residues.
    2. Acute risk. The acute dietary exposure endpoint of concern for 
oxyfluorfen is fused sternebrae in developing pups which was observed 
in the rabbit developmental study. The population subgroup of concern 
is females 13+ years old (women of childbearing age). For this 
subgroup, the calculated MOE at the high end exposure is 5,000. The 
Agency considers dietary (food) MOEs of greater than 100 to be 
acceptable for oxyfluorfen. Acute dietary exposure (food only) was 
calculated using the TMRC (worst case) assumptions.
    In the absence of data for drinking water exposure, the ranges of 
exposure being considered by the Agency for consumption of contaminated 
water will be reserved for drinking water. The aggregate MOE level of 
concern for dietary plus the addition of upperbound estimates for 
drinking water is not likely to raise the MOE level of concern above 
150. Despite the potential for acute exposure to oxyfluorfen in 
drinking water, EPA does not expect the aggregate exposure to exceed 
the Agency's level of concern if the tolerance being considered in this 
document were granted. The Agency has therefore concluded that the 
potential acute exposure associated with oxyfluorfen in water, even at 
the higher levels the Agency is considering as a conservative upper 
bound, would not prevent the Agency from determining that there is a 
reasonable certainty of no harm if the tolerance is granted.

E. Determination of Safety for Infants and Children

    In assessing the potential for additional sensitivity of infants 
and children to residues of oxyfluorfen, 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 pesticide exposure during prenatal development to one or 
both parents. Reproduction studies provide information relating to 
effects from exposure to the pesticide on the reproductive capability 
of mating animals and data on systemic toxicity.
    FFDCA section 408 provides that EPA shall apply an additional 
tenfold margin of safety for infants and children in the case of 
threshold effects to account for pre- and post-natal toxicity and the 
completeness of the database unless EPA determines that a different 
margin of safety will be safe for infants and children. Margins of 
safety are incorporated into EPA risk assessments either directly 
through use of a margin of exposure 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 hundredfold uncertainty (safety) 
factor/margin of exposure (safety) is designed to account for combined 
inter- and intra-species variability. EPA believes that reliable data 
support using the standard hundredfold margin/actor not the additional 
tenfold margin/factor when EPA has a complete database under existing 
guidelines and when the severity of the effect in infants or children 
or the potency or unusual toxic properties of a compound do not raise 
concerns regarding the adequacy of the standard margin/factor.
    The toxicology data base is complete for oxyfluorfen relative to 
pre- and post-natal toxicity. In the developmental toxicity study in 
rabbits, at the maternally toxic dose of 30 mg/kg/day, there were 
developmental anomalies (fused sternebrae) in the fetuses which 
demonstrated that pre-natal toxicity should be evaluated by an acute 
dietary risk estimate. As described above, the acute dietary MOE for 
pregnant women 13+ years old was 5,000 based on the developmental NOEL 
of 10 mg/kg/day. This MOE is much higher than the minimal acceptable 
MOE (100 for dietary-food only) and suggests that pre-natal 
developmental risks to infants and children from exposure to 
oxyfluorfen dietary residues is not a concern. Additionally, the rabbit 
developmental NOEL of 10 mg/kg/day is 33 times greater than the NOEL of 
0.3 mg/kg/day used to calculate the RfD. In the developmental toxicity 
study in rats, both the developmental and maternal NOEL and LOEL of 18 
and 183 mg/kg/day, respectively, occurred at the same dose levels and 
demonstrates that there is no special sensitivity in infants and 
children exposed to oxyfluorfen. Although the developmental findings in 
the rat were severe effects, the developmental NOEL of 18 mg/kg/day is 
greater than the rabbit developmental NOEL of 10 mg/kg/day used to 
calculate acute dietary MOEs. Therefore, the acute dietary risk 
estimates calculated from the rabbit developmental NOEL are lower than 
acute dietary MOEs which could be calculated for the more severe 
effects occurring in rats above the NOEL of 18 mg/kg/day. By basing the 
acute dietary MOEs on the NOEL in the most sensitive species (rabbit), 
pregnant women are protected against both types of pre-natal toxicity 
effects as seen in the rat and rabbit developmental toxicity studies. 
Therefore, there are no

[[Page 20110]]

significant pre-natal toxicity concerns for infants and children due to 
the high MOE for pregnant women 13+ years old. In the 2-generation 
reproductive toxicity study in rats used to assess the post-natal 
toxicity potential of infants and children, the NOEL and LOEL of 20 mg/
kg/day and 80 mg/kg/day, respectively, for developmental/reproductive 
and systemic toxicity demonstrated that there are no pup toxicity 
effects in the absence of parental toxicity (NOEL and LOEL are the same 
for pups and parental animals). Therefore, there are no special post-
natal sensitivities in infants and children which can be attributed to 
the findings of the 2-generation reproductive toxicity study in rats. 
Additionally, the developmental/reproductive NOEL of 20 mg/kg/day 
[which is the NOEL for decreased litter size at birth as well as 
decreased pup body weight] and the parental systemic NOEL of 20 mg/kg/
day is 66 times greater than the NOEL of 0.3 mg/kg/day used to 
calculate the RfD.
    Based on the above, EPA concludes that reliable data support use of 
the standard hundredfold margin of exposure/uncertainty factor and that 
an additional margin/factor is not needed to protect the safety of 
infants and children.
    1. Chronic risk. Using the partially refined, conservative exposure 
assumptions described above and taking into account the completeness 
and reliability of the toxicity data, EPA has concluded that aggregate 
dietary exposure to oxyfluorfen will utilize 1% of the RfD for infants 
and 1.4% of the RfD for children. EPA generally has no concern for 
exposures below 100 percent of the RfD because the RfD represents the 
level at or below which daily aggregate dietary exposure over a 
lifetime will not pose appreciable risks to human health. Despite the 
potential for exposure to oxyfluorfen in drinking water and from non-
dietary, non-occupational exposure, EPA does not expect the chronic 
aggregate exposure to exceed 100% of the RfD. EPA concludes that there 
is a reasonable certainty that no harm will result to infants and 
children from chronic aggregate exposure to oxyfluorfen residues.
    2. Acute risk. As mentioned above, the acute dietary exposure 
endpoint of concern for oxyfluorfen is fused sternebrae in developing 
pups which was observed in the rabbit developmental study. The 
population subgroup of concern is females 13+ years old (women of 
childbearing age). For this subgroup, the calculated MOE at the high 
end exposure is 5,000. The Agency considers dietary (food) MOEs of 
greater than 100 to be acceptable for oxyfluorfen. Acute dietary 
exposure (food only) was calculated using the TMRC (worst case) 
assumptions.
    In the absence of data for drinking water exposure, the ranges of 
exposure being considered by the Agency for consumption of contaminated 
water will be reserved for drinking water. Based on the ranges under 
consideration, the aggregate MOE level of concern for dietary plus the 
addition of drinking water is not likely to raise the MOE above the 
Agency's level of concern. The large MOE calculated for this use of 
oxyfluorfen provides assurance that there is a reasonable certainty of 
no harm for infants and children.

V. Other Considerations

    There is a practical analytical method for detecting and measuring 
levels of oxyfluorfen in or on food with a limit of detection that 
allows monitoring of food with residues at or above the levels set in 
these tolerances. EPA has provided information on this method to FDA. 
The method is available to anyone who is interested in pesticide 
residue enforcement from: By mail, Calvin Furlow, Public Response and 
Program Resources Branch, Field Operations Division (7506C), Office of 
Pesticide Programs, Environmental Protection Agency, 401 M St., SW., 
Washington, DC 20460. Office location and telephone number: Crystal 
Mall #2, Rm. 1128, 1921 Jefferson Davis Highway, Arlington, VA, 703-
305-5805.

VI. Conclusion

    Therefore, a tolerance in connection with the FIFRA section 18 
emergency exemptions is established for residues of oxyfluorfen in/on 
strawberries at 0.05 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 June 24, 1997, file written objections to any 
aspect of this regulation and may also request a hearing on those 
objections. Objections and hearing requests must be filed with the 
Hearing Clerk, at the address given above (40 CFR 178.20). A copy of 
the objections and/or hearing requests filed with the Hearing Clerk 
should be submitted to the OPP docket for this rulemaking. The 
objections submitted must specify the provisions of the regulation 
deemed objectionable and the grounds for the objections (40 CFR 
178.25). Each objection must be accompanied by the fee prescribed by 40 
CFR 180.33(i). If a hearing is requested, the objections must include a 
statement of the factual issues on which a hearing is requested, the 
requestor's contentions on such issues, and a summary of any evidence 
relied upon by the requestor (40 CFR 178.27). A request for a hearing 
will be granted if the Administrator determines that the material 
submitted shows the following: There is genuine and substantial issue 
of fact; there is a reasonable possibility that available evidence 
identified by the requestor would, if established, resolve one or more 
of such issues in favor of the requestor, taking into account 
uncontested claims or facts to the contrary; and resolution of the 
factual issues in the manner sought by the requestor would be adequate 
to justify the action requested (40 CFR 178.32). Information submitted 
in connection with an objection or hearing request may be claimed 
confidential by marking any part or all of that information as 
Confidential Business Information (CBI). Information so marked will not 
be disclosed except in accordance with procedures set forth in 40 CFR 
part 2. A copy of the information that does not contain CBI must be 
submitted for inclusion in the public record. Information not marked 
confidential may be disclosed publicly by EPA without prior notice.

VIII. Public Docket

    A record has been established for this rulemaking under docket 
number [OPP-300478]. A public version of this record, which does not 
include any information claimed as CBI, is available for inspection 
from 8:30 a.m. to 4 p.m., Monday through Friday, excluding legal 
holidays. The public record is located in Room 1132 of the Public 
Response and Program Resources Branch, Field Operations Division 
(7506C), Office of Pesticide Programs, Environmental Protection Agency, 
Crystal Mall #2, 1921 Jefferson Davis Highway, Arlington, VA.
    Electronic comments may be sent directly to EPA at:
    [email protected].


[[Page 20111]]


    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, is kept in paper form. Accordingly, in the 
event there are objections and hearing requests, EPA will transfer any 
copies of objections and hearing requests received electronically into 
printed, paper form as they are received and will place the paper 
copies in the official rulemaking record. The official rulemaking 
record is the paper record maintained at the address in ``ADDRESSES'' 
at the beginning of this document.

IX. Regulatory Assessment Requirements

    Under Executive Order 12866 (58 FR 51735, October 4, 1993), this 
action is not a ``significant regulatory action'' and, since this 
action does not impose any information collection requirements as 
defined by the Paperwork Reduction Act, 44 U.S.C. 3501 et seq., it is 
not subject to review by the Office of Management and Budget. This 
action does not impose any enforceable duty, or contain any ``unfunded 
mandates'' as described in Title II of the Unfunded Mandates Reform Act 
of 1995 (Pub. L. 104-4), or require prior consultation as specified by 
Executive Order 12875 (58 FR 58093, October 28, 1993), entitled 
Enhancing the Intergovernmental Partnership, or special consideration 
as required by Executive Order 12898 (59 FR 7629, February 16, 1994).
    Because FFDCA section 408(l)(6) permits establishment of this 
regulation without a notice of proposed rulemaking, the regulatory 
flexibility analysis requirements of the Regulatory Flexibility Act, 5 
U.S.C. 604(a), do not apply. Nonetheless, the Agency has previously 
assessed whether establishing tolerances or exemptions from tolerance, 
raising tolerance levels, or expanding exemptions adversely impact 
small entities and concluded, as a generic matter, that there is no 
adverse impact. (46 FR 24950, May 4, 1981).
    Under 5 U.S.C. 801(a)(1)(A) of the Small Business Regulatory 
Enforcement Fairness Act of 1996 (Title II of Pub. L. 104-121, 110 
Stat. 847), EPA submitted a report containing this rule and other 
required information to the U.S. Senate, the U.S. House of 
Representatives and the Comptroller General of the General Accounting 
Office prior to publication of the rule in today's Federal Register. 
This rule is not a ``major rule'' as defined by 5 U.S.C. 804(2) of the 
APA as amended.

List of Subjects in 40 CFR Part 180

    Environmental protection, Administrative practice and procedure, 
Agricultural commodities, Pesticides and pests, Reporting and 
recordkeeping requirements.

    Dated: April 16, 1997.

Stephen L. Johnson,
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 180.381 is amended as follows:
    i. In paragraph (a) by adding the heading ``General.''
    ii. By redesignating paragraph (b) as paragraph (c), and adding a 
new paragraph (b).
    iii. In newly designated paragraph (c) by adding a paragraph 
heading ``Tolerances with regional registrations.''
    iv. By adding and reserving new paragraph (d) with the heading 
``Indirect or inadvertent residues.''
    v. By revising the phrase ``raw agricultural'', to read ``food'' 
throughout the section.


Sec. 180.381  Oxyfluorfen; tolerances for residues.

    (a)  General. *  *  *
    (b) Section 18 emergency exemptions. Tolerances are established for 
residues of the herbicide oxyfluorfen [2-chloro-1-(3-ethoxy-4-
nitrophenoxy)-4-(trifluoromethyl)benzene] in or on the following food 
commodities:

------------------------------------------------------------------------
                                                             Expiration/
                   Commodity                     Parts per    Revocation
                                                  million        Date   
------------------------------------------------------------------------
Strawberries..................................         0.05    April 15,
                                                                    1998
------------------------------------------------------------------------

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

[FR Doc. 97-10724 Filed 4-24-97; 8:45 am]
BILLING CODE 6560-50-F