Bromoxynil; Pesticide Tolerances for Emergency Exemptions

Note: EPA no longer updates this information, but it may be useful as a reference or resource.

[Federal Register: September 12, 2001 (Volume 66, Number 177)]
[Rules and Regulations]
[Page 47394-47403]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr12se01-10]

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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
[OPP-301163; FRL-6798-2]
RIN 2070-AB70

AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.

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SUMMARY: This regulation establishes a time-limited tolerance for
residues of bromoxynil in or on timothy, hay and timothy, forage. This
action is in response to EPA's granting of an emergency exemption under
section 18 of the Federal Insecticide, Fungicide, and Rodenticide Act
(FIFRA) authorizing use of the pesticide on timothy. This regulation
establishes a maximum permissible level for residues of bromoxynil in
these commodities. These tolerances will expire and are revoked on June
30, 2003.

DATES: This regulation is effective September 12, 2001. Objections and
requests for hearings, identified by docket control number OPP-301163,
must be received by EPA on or before November 13, 2001.

ADDRESSES: Written objections and hearing requests may be submitted by
mail, in person, or by courier. Please follow the detailed instructions
for each method as provided in Unit VII. of the SUPPLEMENTARY
INFORMATION. To ensure proper receipt by EPA, your objections and
hearing requests must identify docket control number OPP-301163 in the
subject line on the first page of your response.

FOR FURTHER INFORMATION CONTACT: By mail: Barbara Madden, Registration
Division (7505C), Office of Pesticide Programs, Environmental
Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460;
telephone number: (703) 305-6463; and e-mail address:
madden.barbara@epa.gov.

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this Action Apply to Me?

You may be potentially affected by this action if you are an
agricultural producer, food manufacturer, or pesticide manufacturer.
Potentially affected categories and entities may include, but are not
limited to:

[[Page 47395]]

------------------------------------------------------------------------
Examples of
Categories NAICS codes Potentially
Affected Entities
------------------------------------------------------------------------
Industry 111 Crop production
112 Animal production
311 Food manufacturing
32532 Pesticide
manufacturing
------------------------------------------------------------------------

This listing is not intended to be exhaustive, but rather provides
a guide for readers regarding entities likely to be affected by this
action. Other types of entities not listed in the table could also be
affected. The North American Industrial Classification System (NAICS)
codes have been provided to assist you and others in determining
whether or not this action might apply to certain entities. If you have
questions regarding the applicability of this action to a particular
entity, consult the person listed under FOR FURTHER INFORMATION
CONTACT.

B. How Can I Get Additional Information, Including Copies of This
Document and Other Related Documents?

1. Electronically. You may obtain electronic copies of this
document, and certain other related documents that might be available
electronically, from the EPA Internet Home Page at http://www.epa.gov/.
To access this document, on the Home Page select ``Laws and
Regulations,'' ``Regulations and Proposed Rules,'' and then look up the
entry for this document under the ``Federal Register--Environmental
Documents.'' You can also go directly to the Federal Register listings
at http://www.epa.gov/fedrgstr/. A frequently updated electronic
version of 40 CFR part 180 is available at http://www.access.gpo.gov/
nara/cfr/cfrhtml_180/Title_40/40cfr180_00.html, a beta site currently
under development.
2. In person. The Agency has established an official record for
this action under docket control number OPP-301163. The official record
consists of the documents specifically referenced in this action, and
other information related to this action, including any information
claimed as Confidential Business Information (CBI). This official
record includes the documents that are physically located in the
docket, as well as the documents that are referenced in those
documents. The public version of the official record does not include
any information claimed as CBI. The public version of the official
record, which includes printed, paper versions of any electronic
comments submitted during an applicable comment period is available for
inspection in the Public Information and Records Integrity Branch
(PIRIB), Rm. 119, Mall #2, 1921 Jefferson Davis Hwy., Arlington, VA,
from 8:30 a.m. to 4 p.m., Monday through Friday, excluding legal
holidays. The PIRIB telephone number is (703) 305-5805.

II. Background and Statutory Findings

EPA, on its own initiative, in accordance with sections 408(e) and
408(l)(6) of the Federal Food, Drug, and Cosmetic Act (FFDCA), 21
U.S.C. 346a, is establishing tolerances for residues of the insecticide
bromoxynil, 3,5-dibromo-4-hydroxybenzonitrile, in or on timothy, hay at
0.50 part per million (ppm) and timothy, forage at 0.10 ppm. These
tolerances will expire and are revoked on June 30, 2003. EPA will
publish a document in the Federal Register to remove the revoked
tolerance from the Code of Federal Regulations.
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. EPA does not intend for its actions on
section 18 related tolerances to set binding precedents for the
application of section 408 and the new safety standard to other
tolerances and exemptions. Section 408(e) of the FFDCA allows EPA to
establish a tolerance or an exemption from the requirement of a
tolerance on its own initiative, i.e., without having received any
petition from an outside party.
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 the Food Quality Protection Act (FQPA). EPA has established
regulations governing such emergency exemptions in 40 CFR part 166.

III. Emergency Exemption for Bromoxynil on Timothy and FFDCA
Tolerances

On May 4, 2001, the Nevada Department of Agriculture availed
themselves of the authority to declare a crisis exemption for use of
bromoxynil in fields planted with both timothy and alfalfa to control
weeds. Very recent overplanting of aging alfalfa fields with timothy
revealed a problem with weed control in that no registered herbicides
are available for use on alfalfa and timothy that do not damage the
other crop. Bromoxynil, which is registered for use on alfalfa, does
not damage timothy. The crisis declaration was made because alfalfa
growth had reached a point where applications would be ineffective if
done any later in the season. EPA has authorized under FIFRA section 18
the use of bromoxynil on timothy for control of weeds in Nevada.
As part of its assessment of this emergency exemption, EPA assessed
the potential risks presented by residues of bromoxynil in or on
timothy, hay and timothy, forage. In doing so, EPA considered the
safety standard in FFDCA section 408(b)(2), and EPA decided that the
necessary tolerance under FFDCA section 408(l)(6) would be consistent
with the safety standard and with FIFRA section 18. Consistent with the
need to move quickly on the emergency exemption in order to address an
urgent non-routine situation and to ensure that the resulting food is
safe and lawful, EPA is issuing these tolerances without notice and
opportunity for public comment as provided in section 408(l)(6).
Although these tolerances will expire and are revoked on June 30, 2003,
under FFDCA section 408(l)(5), residues of the pesticide not in excess
of the amounts specified in the tolerance remaining in or on timothy,
hay and timothy, forage 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 this
tolerance at the time of that application. EPA will take action to
revoke this tolerance

[[Page 47396]]

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 bromoxynil
meets EPA's registration requirements for use on timothy or whether
permanent tolerances for this use would be appropriate. Under these
circumstances, EPA does not believe that these tolerances serve as a
basis for registration of bromoxynil by a State for special local needs
under FIFRA section 24(c). Nor does this tolerance serve as the basis
for any State other than Nevada to use this pesticide on this crop
under section 18 of FIFRA without following all provisions of EPA's
regulations implementing section 18 as identified in 40 CFR part 166.
For additional information regarding the emergency exemption for
bromoxynil, contact the Agency's Registration Division at the address
provided under FOR FURTHER INFORMATION CONTACT.

IV. Aggregate Risk Assessment and Determination of Safety

EPA performs a number of analyses to determine the risks from
aggregate exposure to pesticide residues. For further discussion of the
regulatory requirements of section 408 and a complete description of
the risk assessment process, see the final rule on Bifenthrin Pesticide
Tolerances (62 FR 62961, November 26, 1997) (FRL-5754-7).
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
bromoxynil and to make a determination on aggregate exposure,
consistent with section 408(b)(2), for time-limited tolerances for
residues of bromoxynil in or on timothy, hay at 0.50 ppm and timothy,
forage at 0.10 ppm. EPA's assessment of the dietary exposures and risks
associated with establishing the tolerance follows.

A. Toxicological Endpoints

The dose at which no adverse effects are observed (the NOAEL) from
the toxicology study identified as appropriate for use in risk
assessment is used to estimate the toxicological endpoint. However, the
lowest dose at which adverse effects of concern are identified (the
LOAEL) is sometimes used for risk assessment if no NOAEL was achieved
in the toxicology study selected. An uncertainty factor (UF) is applied
to reflect uncertainties inherent in the extrapolation from laboratory
animal data to humans and in the variations in sensitivity among
members of the human population as well as other unknowns. An UF of 100
is routinely used, 10X to account for interspecies differences and 10X
for intraspecies differences.
For dietary risk assessment (other than cancer) the Agency uses the
UF to calculate an acute or chronic reference dose (acute RfD or
chronic RfD) where the RfD is equal to the NOAEL divided by the
appropriate UF (RfD = NOAEL/UF). Where an additional safety factor is
retained due to concerns unique to the FQPA, this additional factor is
applied to the RfD by dividing the RfD by such additional factor. The
acute or chronic Population Adjusted Dose (aPAD or cPAD) is a
modification of the RfD to accommodate this type of FQPA Safety Factor.
For non-dietary risk assessments (other than cancer) the UF is used
to determine the level of concern (LOC). For example, when 100 is the
appropriate UF (10X to account for interspecies differences and 10X for
intraspecies differences) the LOC is 100. To estimate risk, a ratio of
the NOAEL to exposures (margin of exposure (MOE) = NOAEL/exposure) is
calculated and compared to the LOC.
The linear default risk methodology (Q*) is the primary method
currently used by the Agency to quantify carcinogenic risk. The Q*
approach assumes that any amount of exposure will lead to some degree
of cancer risk. A Q* is calculated and used to estimate risk which
represents a probability of occurrence of additional cancer cases
(e.g., risk is expressed as 1 x 10-\6\ or one in a million).
Under certain specific circumstances, MOE calculations will be used for
the carcinogenic risk assessment. In this non-linear approach, a
``point of departure'' is identified below which carcinogenic effects
are not expected. The point of departure is typically a NOAEL based on
an endpoint related to cancer effects though it may be a different
value derived from the dose response curve. To estimate risk, a ratio
of the point of departure to exposure (MOE_cancer = point of
departure/exposures) is calculated. A summary of the toxicological
endpoints for bromoxynil used for human risk assessment is shown in the
following Table 1:

Table 1.--Summary of Toxicological Dose and Endpoints for Bromoxynil for Use in Human Risk Assessment
----------------------------------------------------------------------------------------------------------------
FQPA SF* and Level of
Exposure Scenario Dose Used in Risk Concern for Study and Toxicological
Assessment, UF RiskAssessment Effects
----------------------------------------------------------------------------------------------------------------
Acute Dietary females 13-50 years of NOAEL = 4 mg/kg/day FQPA SF = 10 Developmental toxicity
age UF = 100............... aPAD = acute RfD study where bromoxynil
Acute RfD = 0.04 mg/kg/ FQPA SF. phenol was
day. = 0.004 mg/kg/day...... administered to rats.
LOAEL = 5 mg/kg/day
based on an increased
incidence of
supernumerary ribs in
rats from a
developmental toxicity
study.
----------------------------------------------------------------------------------------------------------------
Acute Dietary general population NOAEL = 8 mg/kg/day FQPA SF = 1 13-Week range-finding
including infants and children UF =100................ aPAD = acute RfD study in which
Acute RfD = 0.08 mg/kg/ FQPA SF. bromoxynil phenol was
day. = 0.08 mg/kg/day....... administered orally to
dogs.
LOAEL = 12 mg/kg/day
based on increased
incidence of panting
on day 1, suggestive
of a compensatory
reaction to the
effects of the test
material, which at
higher doses is
expressed as elevated
body temperature.
----------------------------------------------------------------------------------------------------------------

[[Page 47397]]

Chronic Dietary all populations NOAEL= 1.5 mg/kg/day FQPA SF = 1 12-Month chronic oral
UF = 100.............. cPAD = chronic RfD toxicity study in dogs
Chronic RfD = 0.015 mg/ FQPA SF. using bromoxynil
kg/day. = 0.015 mg/kg/day...... phenol as the test
material. Threshold
NOAEL/LOAEL of 1.5 mg/
kg/day based on
slightly decreased
body weight gain in
males. At the next
higher dose level (7.5
mg/kg/day), the
following effects were
observed in both males
and females: decreased
body weight gain;
increased salivation,
panting, liquid feces,
and pale gums;
decreased
erythrocytes,
hemoglobin, and packed
cell volume; increased
urea nitrogen; and
increased liver
weights.
----------------------------------------------------------------------------------------------------------------
Cancer (oral, dermal, inhalation) Bromoxynil phenol has 10-\6\ The weight-of-the-
been classified as a evidence determination
Group C, possible was based primarily on
human carcinogen. A results in two mouse
low dose extrapolation carcinogenicity
model (Q1*) is applied studies.
for quantification of
human risk. Q1* = 1.03
x 10-\1\ (mg/kg/day)-
\1\
----------------------------------------------------------------------------------------------------------------
* The reference to the FQPA Safety Factor refers to any additional safety factor retained due to concerns unique
to the FQPA.

B. Exposure Assessment

1. Dietary exposure from food and feed uses. Tolerances have been
established (40 CFR 180.324) for the residues of bromoxynil, in or on a
variety of raw agricultural commodities including alfalfa, barley,
corn, flax, garlic, mint, oats, onions, rye, sorghum, wheat, and
cotton. Tolerances have also been established on fat, meat, and meat-
by-products of cattle, goats, hogs, horses, poultry, and sheep as well
as eggs and milk. Risk assessments were conducted by EPA to assess
dietary exposures from bromoxynil in food as follows.
Bromoxynil is currently registered for use on alfalfa. The
aggregate risks associated with the use of bromoxynil on alfalfa have
been assessed previously (Reregistration Eligibility Decision (RED)
document, Decmeber 1998). No residue data are available for bromoxynil
on timothy. As the use directions for timothy-alfalfa stands are the
same as for alfalfa alone, the state has proposed to translate the
existing residue data for alfalfa (a member of Crop Group 18, Nongrass
Animal Feeds) to timothy (a member of Crop Group 17; Grass Forage,
Fodder and Hay). This translation would generally not be possible as
the timothy, forage tolerance would be based on 0-day preharvest
interval (PHI) data whereas the PHI for alfalfa, forage is 30 days.
However, as the cultural practices for timothy-alfalfa stands is the
same as that for alfalfa alone, for the emergency exemption only, the
Agency is willing to translate the existing alfalfa residue data to
timothy. Based upon the alfalfa residue data, the following tolerances
are thus appropriate for timothy, hay at 0.50 ppm and timothy, forage
at 0.10 ppm.
There are no human food items associated with timothy and
therefore, the use of bromoxynil on timothy will not increase the
potential for secondary residues in livestock (since the residues in
timothy will not exceed those on alfalfa, a more significant feed
item), the dietary risk associated with bromoxynil will not be effected
by this use. The potential for residues in drinking water will not be
effected as the use rate for timothy-alfalfa stands is the same as for
alfalfa alone. Thus, revised risk assessments were not conducted for
this action. The information discussed below was previously discussed
in the December 1998 RED document.
i. 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. In 1998, an acute (probabilistic) dietary analysis
including the cotton use was performed by Novigen Sciences, Inc. for
Rhone Poulenc. The assessment used the consumption data from the USDA
1989-1992 nationwide Continuing Survey of Food Intakes by Individuals
(CSFII).
The acute dietary risk assessment was conducted as a probabilistic
risk assessment, assuming single day exposure. In the assessment, each
person-day of food consumption was matched with randomly selected
residue values for this assessment from field trails submitted in
support of the chemical. Percent crop treated data were included in the
assessment as zeroes to account for portions of the crop to which
bromoxynil was not applied. This process was repeated one thousand
times for each person-day in consumption data base. The assessment
assumed that the treated commodities were evenly distributed in the
food supply. Secondary residues in meat and milk from consumption of
treated feed items were included in the form of a probabilistic
assessment, varying residues in the diet in accordance with the data
from the field trials. The assumptions for the dietary exposure were
reviewed and found to be acceptable. The assessments assumed that 10%
of the cotton crop would be treated.
Anticipated residues in blended commodities (such as grains,
cottonseed and mint oil) were used, without an adjustment for percent
crop treated; however, tolerance level residues were used for onions,
garlic, fat, meat by-products, and meat of cattle, goats, hogs, horses,
sheep, and poultry, and eggs. Milk is a blended commodity, and
therefore an anticipated residue was used.
ii. Chronic/cancer exposure. In conducting this chronic dietary
risk

[[Page 47398]]

assessment the Dietary Risk Evaluation System (DRES) analysis evaluated
the individual food consumption as reported by respondents in the USDA
1989-1992 nationwide CSFII and accumulated exposure to the chemical for
each commodity. The following assumptions were made for the chronic
exposure assessments: Field trial residues in raw agricultural
commodities (RACs) consumed by people were nondetectable; anticipated
residues were based on 1/2 the limit of quantitation (LOQ), and were
further refined by percent crop treated data. Field trial residues from
all forages (i.e., sorghum, wheat, oat, corn, alfalfa), and all hays
were averaged, and the additional refinement for percent crop treated
was applied. Although forages and hays contained detectable bromoxynil
residues, the averages used were significantly lower than tolerance-
level residues.
The contribution of cotton gin products (gin trash) to the dietary
burden for ruminants was assumed to be 5% of the diet for beef cattle
and 1% for dairy cattle. It was assumed that 10% of cotton was treated.
The only commodities which contribute significantly to exposure to
bromoxynil and/or DBHA in the diet for the general U.S. population (or
any subpopulation) are meat, milk, poultry, and eggs, based on
secondary residues resulting from consumption of livestock feed items.
iii. Anticipated residue and percent crop treated information.
Section 408(b)(2)(E) authorizes EPA to use available data and
information on the anticipated residue levels of pesticide residues in
food and the actual levels of pesticide chemicals that have been
measured in food. If EPA relies on such information, EPA must require
that data be provided 5 years after the tolerance is established,
modified, or left in effect, demonstrating that the levels in food are
not above the levels anticipated. Following the initial data
submission, EPA is authorized to require similar data on a time frame
it deems appropriate. As required by section 408(b)(2)(E), EPA will
issue a Data Call-In for information relating to anticipated residues
to be submitted no later than 5 years from the date of issuance of this
tolerance.
Section 408(b)(2)(F) states that the Agency may use data on the
actual percent of food treated for assessing chronic dietary risk only
if the Agency can make the following findings:
Condition 1, that the data used are reliable and provide a
valid basis to show what percentage of the food derived from such crop
is likely to contain such pesticide residue.
Condition 2, that the exposure estimate does not
underestimate exposure for any significant subpopulation group.
Condition 3, if data are available on pesticide use and
food consumption in a particular area, the exposure estimate does not
understate exposure for the population in such area. In addition, the
Agency must provide for periodic evaluation of any estimates used. To
provide for the periodic evaluation of the estimate of PCT as required
by section 408(b)(2)(F), EPA may require registrants to submit data on
PCT.
The Agency used PCT information as follows: 10% of the cereal
grains (wheat, corn, oats, barley, rye, sorghum, including processed
commodities) treated; 62% of onions treated; 100% garlic treated; 71%
of the peppermint and spearmint treated, and 10% of the cotton treated.
Refer to the December 1998 RED docucment for additional information.
The Agency believes that the three conditions listed above have
been met. With respect to Condition 1, PCT estimates are derived from
Federal and private market survey data, which are reliable and have a
valid basis. EPA uses a weighted average PCT for chronic dietary
exposure estimates. This weighted average PCT figure is derived by
averaging State-level data for a period of up to 10 years, and
weighting for the more robust and recent data. A weighted average of
the PCT reasonably represents a person's dietary exposure over a
lifetime, and is unlikely to underestimate exposure to an individual
because of the fact that pesticide use patterns (both regionally and
nationally) tend to change continuously over time, such that an
individual is unlikely to be exposed to more than the average PCT over
a lifetime. For acute dietary exposure estimates, EPA uses an estimated
maximum PCT. The exposure estimates resulting from this approach
reasonably represent the highest levels to which an individual could be
exposed, and are unlikely to underestimate an individual's acute
dietary exposure. The Agency is reasonably certain that the percentage
of the food treated is not likely to be an underestimation. As to
Conditions 2 and 3, regional consumption information and consumption
information for significant subpopulations is taken into account
through EPA's computer-based model for evaluating the exposure of
significant subpopulations including several regional groups. Use of
this consumption information in EPA's risk assessment process ensures
that EPA's exposure estimate does not understate exposure for any
significant subpopulation group and allows the Agency to be reasonably
certain that no regional population is exposed to residue levels higher
than those estimated by the Agency. Other than the data available
through national food consumption surveys, EPA does not have available
information on the regional consumption of food to which bromoxynil may
be applied in a particular area.
2. Dietary exposure from drinking water--i. Ground water.
Bromoxynil octanoate does not exhibit the mobility or persistence
characteristics of pesticides that are normally found in ground water.
Bromoxynil phenol (which bromoxynil octanoate readily degrades to) has
the potential to leach to ground water under certain conditions;
however, it rapidly degrades under aerobic and anaerobic conditions
reducing the likelihood of ground water contamination. Limited
monitoring information for bromoxynil in ground water is available. The
``Pesticides in Ground Water Database'' (EPA 1992) reports sampling for
bromoxynil in 107 wells in four counties in Oregon between 1985 and
1987. The well samples in each area (public water supply and domestic)
were selected based on suspected vulnerability, susceptibility to
contamination, and availability of information on well construction and
depth. No additional information on the details of the monitoring was
available. No detections of bromoxynil were reported.
Additional monitoring data from the United States Geological Survey
(USGS) National Water Quality Program (NAQWA) represent the highest
quality data and most recent data available (1993-1994). The program
was carefully designed to obtain monitoring data for surface and ground
waters from diffuse (non-point) sources. For ground water, one
detection of bromoxynil (concentration not specified) was reported from
a total of 2,245 samples. Clearly, these compounds (bromoxynil phenol
and octanoate) are not considered candidates for restricted use due to
ground water concerns and the potential for ground water contamination
(and exposure) from bromoxynil is extremely low.
DBHA, a cotton metabolite, is not expected to be found in ground
water.
ii. Surface water. Environmental fate studies indicate that
bromoxynil (phenol and octanoate) should not persist in surface waters,
although water monitoring data from the USGS NAWQA program show that
bromoxynil has been detected in 1.1% of surface water samples. Modeled
estimated environmental concentrations (EECs)

[[Page 47399]]

were based on the cotton use and not the small grains, corn or other
uses of bromoxynil because, it has been the Agency's experience, that
using cotton as opposed to these crops results in a higher estimated
surface water exposure. Cotton represents the most conservative use for
surface water exposure (i.e., the highest possible exposure scenario).
A Tier II analysis based on the PRZM-EXAMS model (Pesticide Root
Zone Model Version 2.3 plus Exposure Analysis Modeling System Version
2.94) was conducted for the cotton use. PRZM-EXAMS uses data on the
physical-chemical properties of the pesticide plus soil and topographic
characteristics, weather data, and water quality parameters for the
modeled site. The model uses this information to estimate runoff from a
10 hectare agricultural field into an immediately adjacent 1 hectare by
2 meter deep pond. PRZM-EXAMS considers reduction in dissolved
pesticide concentrations due to adsorption of pesticide to soil or
sediment, incorporation, degradation in soil before wash off to a water
body, direct deposition of spray drift into the water body, and
degradation of the pesticide within the water body.
Water monitoring data from the USGS NAWQA Program were reported
during the 1993-1995 period from 7 of 20 river basins throughout the
U.S. The NAWQA Program examined drainage basins that were primarily
agricultural use. The percentage of detections was 1.1% from a total of
1,925 surface water samples. Analysis of the 20 detections >0.03 parts
per billion (ppb) yielded a median value of 0.105 ppb with a mean of
0.53 ppb. The maximum concentration was one data point at 6.1 ppb (12.2
ppb when accounting for 50% recovery) measured in the South Platte
River Study Unit, CO. For urban land use, bromoxynil was not detected
in surface waters. It is important to note the laboratory recoveries
were approximately 50%. Apparently the laboratory recoveries did not
vary considerably from the 50% level.
Based on model estimates (using PRZM-EXAMS), the maximum or peak
estimated concentration for bromoxynil was 12.3 ppb and the maximum
estimated long-term mean was 0.24 ppb (using 36 years of weather data).
These values represent what might be expected in a small water body
near a cotton field highly prone to runoff. The maximum peak estimated
concentration for bromoxynil from the model correlates with the highest
value detected in the USGS monitoring data, when this measured value
has been corrected for an analytical recovery rate of 50%.
To estimate a reasonable high end exposure for the human health
risk assessment, EPA focused on the calculated time-weighted annual
mean concentrations of bromoxynil at each of 11 USGS monitoring sites,
which the EPA views as located in watersheds likely to have bromoxynil
use. (These values were not corrected for the analytical recovery rate
of 50%.) These time-weighted annual mean concentrations ranged from
0.011 ppb to 0.18 ppb, with 10 out of the 11 sites with time-weighted
annual mean concentrations below 0.05 ppb. Six of the 10 sites had time
weighted annual mean concentrations at or below 0.014 ppb. The highest
annual time-weighted mean (0.18 ppb) was located in a relatively small
watershed (approximately 100 square miles) in a relatively small water
body, and the calculated annual mean value at this site was
significantly influenced by the presence of a single high value (the
highest value found in all of the available monitoring data). Based on
this information, EPA believes that 0.05 ppb is a reasonable high end
estimate for purposes of estimating drinking water exposure.
3. From non-dietary exposure. The term ``residential exposure'' is
used in this document to refer to non-occupational, non-dietary
exposure (e.g., for lawn and garden pest control, indoor pest control,
termiticides, and flea and tick control on pets). Bromoxynil is not
registered for use on any sites that would result in residential
exposure.
4. Cumulative exposure to substances with a 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.''
EPA does not have, at this time, available data to determine
whether bromoxynil 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,
bromoxynil 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 bromoxynil has a common mechanism of toxicity
with other substances. For information regarding EPA's efforts to
determine which chemicals have a common mechanism of toxicity and to
evaluate the cumulative effects of such chemicals, see the final rule
for Bifenthrin Pesticide Tolerances (62 FR 62961, November 26, 1997).

C. Safety Factor for Infants and Children

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 prenatal and postnatal toxicity and
the completeness of the data base on toxicity and exposure 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 (MOE)
analysis or through using uncertainty (safety) factors in calculating a
dose level that poses no appreciable risk to humans.
The bromoxynil data submitted to the Agency for review are
sufficient for the assessment of hazard to the developing organism. A
total of 11 developmental and 3 reproductive toxicity studies were
available for review. These include oral prenatal developmental
toxicity studies (three in rats, two in rabbits, and one in mice with
the phenol; one in rats with the octanoate), dermal prenatal
developmental toxicity studies (one each in rats and rabbits with both
the phenol and the octanoate), and two dietary two-generation
reproduction studies in rats (one with the phenol; one with the
octanoate) and one dermal reproduction study. Developmental toxicity
was observed, following in utero exposure to bromoxynil, in multiple
studies, by two routes of exposure, and in three species. The induction
of supernumerary ribs was shown to be the most sensitive indicator of
developmental toxicity in fetal rats, mice, and (in certain studies)
rabbits. Upon consideration of the data base in its entirety, the
Agency determined that the developmental NOAEL, for the induction of
supernumerary ribs, resulting from prenatal exposure to bromoxynil
(phenol) is 4 mg/kg/day via the oral route and 10 mg/kg/day via the
dermal route. The developmental LOAELs for bromoxynil phenol were 5 mg/
kg/day by the oral route and 50 mg/kg/day by the dermal route. Other
forms of developmental toxicity, including resorptions and
malformations, were routinely observed in bromoxynil studies at higher
dose levels.
It was determined that the FQPA safety factor should be retained
for the subpopulation consisting of females 13+ for acute dietary
exposures. This

[[Page 47400]]

decision was based upon concerns emanating from the toxicological
profile, including evidence of increased susceptibility of fetuses to
bromoxynil exposure, the steep dose response curve, and the
demonstrated severe developmental effects at doses above the LOAEL.
The population of concern is the developing fetus and the endpoint
of concern is supernumerary ribs. This endpoint, a developmental
anomaly, results from in utero exposure; therefore the population
subgroup of concern is females 13+ years old. Although some systems in
infants and children continue developing, it is unlikely that
supernumerary ribs, even though observed across multiple species, would
result from postnatal exposure. A 10-fold safety factor, as required by
FQPA, will provide additional protection for infants and children and
ensure a reasonable certainty of no harm to this sensitive
subpopulation.

D. Aggregate Risks and Determination of Safety

1. Acute risk. Using the exposure assumptions discussed in this
unit for acute exposure and dietary exposure from drinking water, the
acute aggregate exposure from food and water to bromoxynil will occupy
<1% of the aPAD for the U.S. population, 11% of the aPAD for females 13
years and older, 2% of the aPAD for all infants and 2% of the aPAD for
children 1-6 years old. Therefore, EPA does not expect the aggregate
exposure to exceed 100% of the aPAD, as shown in the following Table 2:

Table 2.--Aggregate Risk Assessment for Acute Exposure to Bromoxynil
----------------------------------------------------------------------------------------------------------------
Estimated Exposure Estimated Exposure
Population Subgroup aPAD (mg/kg) from Food (mg/kg from Water (mg/kg/ % aPAD (Food and
bw/day) day) Water)
----------------------------------------------------------------------------------------------------------------
U.S. population 0.08 0.000137 0.00035 <1%
----------------------------------------------------------------------------------------------------------------
Females 13+ years 0.004 0.000082 0.00035 11%
----------------------------------------------------------------------------------------------------------------
Children (1-6 years old) 0.08 0.000288 0.0012 2%
----------------------------------------------------------------------------------------------------------------
All infants 0.08 0.000219 0.0012 2%
----------------------------------------------------------------------------------------------------------------

2. Chronic risk. Using the exposure assumptions described in this
unit for chronic exposure and dietary exposure from drinking water, EPA
has concluded that exposure to bromoxynil from food and water will
utilize <1% of the cPAD for the U.S. population, <1% of the cPAD for
all infants, and <1% of the cPAD for children 1-6 years old. There are
no residential uses for bromoxynil that result in chronic residential
exposure to bromoxynil. Therefore, EPA does not expect the aggregate
exposure to exceed 100% of the cPAD, as shown in the following Table 3:

Table 3.-- Aggregate Risk Assessment for Chronic (Non-Cancer) Exposure to Bromoxynil
----------------------------------------------------------------------------------------------------------------
Estimated Exposure Estimated Exposure
Population Subgroup cPAD (mg/kg) from Food (mg/kg from Water (mg/kg/ % cPAD (Food and
bw/day) day) Water)
----------------------------------------------------------------------------------------------------------------
U.S. population 0.015 0.000015 0.0000014 <1%
----------------------------------------------------------------------------------------------------------------
Females 13+ years 0.015 0.000012 0.0000016 <1%
----------------------------------------------------------------------------------------------------------------
Children (1-6 years old) 0.015 0.000032 0.000005 <1%
----------------------------------------------------------------------------------------------------------------
All Infants 0.015 0.000036 0.000005 <1%
----------------------------------------------------------------------------------------------------------------

3. Short-term risk. Short-term aggregate exposure takes into
account residential exposure plus chronic exposure to food and water
(considered to be a background exposure level). Bromoxynil is not
registered for use on any sites that would result in residential
exposure. Therefore, the aggregate risk is the sum of the risk from
food and water, which were previously addressed.
4. Intermediate-term risk. Intermediate-term aggregate exposure
takes into account non-dietary, non-occupational exposure plus chronic
exposure to food and water (considered to be a background exposure
level). Bromoxynil is not registered for use on any sites that would
result in residential exposure. Therefore, the aggregate risk is the
sum of the risk from food and water, which were previously addressed.
5. Aggregate cancer risk for U.S. population. Using the exposure
assumptions described in this unit for chronic/cancer exposure and
dietary exposure from drinking water, EPA has concluded that exposure
to bromoxynil from food and water resulted in an estimated aggregate
cancer risk to the U.S. population of 1.7 x 10-\6\.
Bromoxynil is not registered for use on any sites that would result in
residential exposure. Therefore, the aggregate cancer risk is the sum
of the risk from food and water only.
6. Determination of safety. Based on these risk assessments, EPA
concludes that there is a reasonable certainty that no harm will result
to the general population, and to infants and children from aggregate
exposure to bromoxynil residues.

V. Other Considerations

A. Analytical Enforcement Methodology

Adequate analytical methodology is available for data collection
and tolerance enforcement for bromoxynil per se in plants. Method I in
PAM, Vol. II, is a GLC/MCD that has undergone a successful EPA method
validation on

[[Page 47401]]

wheat grain. This method involves alkaline hydrolysis in methanolic KOH
to convert residues to bromoxynil, cleanup by liquid-liquid
partitioning, methylation using diazomethane, further cleanup on a
Florisil column, and determination by GLC/MCD. Method Ia is the same
method, but uses GC/ECD for determination of methylated bromoxynil.
Method A is a GC/MCD or ECD method for the analysis of bromoxynil
residues in livestock tissues and is essentially the same as Method I.
Method B is a GC/ECD method that is also similar to Method I, with
modifications to the cleanup procedures.

B. International Residue Limits

There are no established or proposed Codex maximum residue levels
for bromoxynil residues; no compatibility questions exist with respect
to U.S. tolerances and Codex.

VI. Conclusion

Therefore, the tolerance is established for residues of bromoxynil,
3,5-dibromo-4-hydroxybenzonitrile, in or on timothy, hay at 0.50 ppm
and timothy, forage at 0.10 ppm.

VII. Objections and Hearing Requests

Under section 408(g) of the FFDCA, as amended by the FQPA, any
person may file an objection to any aspect of this regulation and may
also request a hearing on those objections. The EPA procedural
regulations which govern the submission of objections and requests for
hearings appear in 40 CFR part 178. Although the procedures in those
regulations require some modification to reflect the amendments made to
the FFDCA by the FQPA of 1996, EPA will continue to use those
procedures, with appropriate adjustments, until the necessary
modifications can be made. The new section 408(g) provides essentially
the same process for persons to ``object'' to a regulation for an
exemption from the requirement of a tolerance issued by EPA under new
section 408(d), as was provided in the old FFDCA sections 408 and 409.
However, the period for filing objections is now 60 days, rather than
30 days.

A. What Do I Need to Do to File an Objection or Request a Hearing?

You must file your objection or request a hearing on this
regulation in accordance with the instructions provided in this unit
and in 40 CFR part 178. To ensure proper receipt by EPA, you must
identify docket control number OPP-301163 in the subject line on the
first page of your submission. All requests must be in writing, and
must be mailed or delivered to the Hearing Clerk on or before November
13, 2001.
1. Filing the request. Your objection must specify the specific
provisions in the regulation that you object to, and the grounds for
the objections (40 CFR 178.25). If a hearing is requested, the
objections must include a statement of the factual issues(s) on which a
hearing is requested, the requestor's contentions on such issues, and a
summary of any evidence relied upon by the objector (40 CFR 178.27).
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.
Mail your written request to: Office of the Hearing Clerk (1900),
Environmental Protection Agency, 1200 Pennsylvania Ave., NW.,
Washington, DC 20460. You may also deliver your request to the Office
of the Hearing Clerk in Rm. C400, Waterside Mall, 401 M St., SW.,
Washington, DC 20460. The Office of the Hearing Clerk is open from 8
a.m. to 4 p.m., Monday through Friday, excluding legal holidays. The
telephone number for the Office of the Hearing Clerk is (202) 260-4865.
2. Tolerance fee payment. If you file an objection or request a
hearing, you must also pay the fee prescribed by 40 CFR 180.33(i) or
request a waiver of that fee pursuant to 40 CFR 180.33(m). You must
mail the fee to: EPA Headquarters Accounting Operations Branch, Office
of Pesticide Programs, P.O. Box 360277M, Pittsburgh, PA 15251. Please
identify the fee submission by labeling it ``Tolerance Petition Fees.''
EPA is authorized to waive any fee requirement ``when in the
judgement of the Administrator such a waiver or refund is equitable and
not contrary to the purpose of this subsection.'' For additional
information regarding the waiver of these fees, you may contact James
Tompkins by phone at (703) 305-5697, by e-mail at tompkins.jim@epa.gov,
or by mailing a request for information to Mr. Tompkins at Registration
Division (7505C), Office of Pesticide Programs, Environmental
Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460.
If you would like to request a waiver of the tolerance objection
fees, you must mail your request for such a waiver to: James Hollins,
Information Resources and Services Division (7502C), Office of
Pesticide Programs, Environmental Protection Agency, 1200 Pennsylvania
Ave., NW., Washington, DC 20460.
3. Copies for the docket. In addition to filing an objection or
hearing request with the Hearing Clerk as described in Unit VII.A., you
should also send a copy of your request to the PIRIB for its inclusion
in the official record that is described in Unit I.B.2. Mail your
copies, identified by the docket control number OPP-301163, to: Public
Information and Records Integrity Branch, Information Resources and
Services Division (7502C), Office of Pesticide Programs, Environmental
Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460.
In person or by courier, bring a copy to the location of the PIRIB
described in Unit I.B.2. You may also send an electronic copy of your
request via e-mail to: opp-docket@epa.gov. Please use an ASCII file
format and avoid the use of special characters and any form of
encryption. Copies of electronic objections and hearing requests will
also be accepted on disks in WordPerfect 6.1/8.0 or ASCII file format.
Do not include any CBI in your electronic copy. You may also submit an
electronic copy of your request at many Federal Depository Libraries.

B. When Will the Agency Grant a Request for a Hearing?

A request for a hearing will be granted if the Administrator
determines that the material submitted shows the following: There is a
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(s) in the manner sought
by the requestor would be adequate to justify the action requested (40
CFR 178.32).

VIII. Regulatory Assessment Requirements

This final rule establishes a time-limited tolerance under FFDCA
section 408. 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

[[Page 47402]]

Reform Act of 1995 (UMRA) (Public Law 104-4). Nor does it require any
special considerations under Executive Order 12898, entitled Federal
Actions to Address Environmental Justice in Minority Populations and
Low-Income Populations (59 FR 7629, February 16, 1994); or OMB review
or any other Agency action under Executive Order 13045, entitled
Protection of Children from Environmental Health Risks and Safety Risks
(62 FR 19885, April 23, 1997). This action does not involve any
technical standards that would require Agency consideration of
voluntary consensus standards pursuant to section 12(d) of the National
Technology Transfer and Advancement Act of 1995 (NTTAA), Public Law
104-113, section 12(d) (15 U.S.C. 272 note). Since tolerances and
exemptions that are established on the basis of a FIFRA section 18
exemption under FFDCA section 408, such as the tolerance in this final
rule, do not require the issuance of a proposed rule, the requirements
of the Regulatory Flexibility Act (RFA) (5 U.S.C. 601 et seq.) do not
apply. In addition, the Agency has determined that this action will not
have a substantial direct effect on States, on the relationship between
the national government and the States, or on the distribution of power
and responsibilities among the various levels of government, as
specified in Executive Order 13132, entitled Federalism (64 FR 43255,
August 10, 1999). Executive Order 13132 requires EPA to develop an
accountable process to ensure ``meaningful and timely input by State
and local officials in the development of regulatory policies that have
federalism implications.'' ``Policies that have federalism
implications'' is defined in the Executive Order to include regulations
that have ``substantial direct effects on the States, on the
relationship between the national government and the States, or on the
distribution of power and responsibilities among the various levels of
government.'' This final rule directly regulates growers, food
processors, food handlers and food retailers, not States. This action
does not alter the relationships or distribution of power and
responsibilities established by Congress in the preemption provisions
of FFDCA section 408(n)(4).
For these same reasons, the Agency has determined that this rule
does not have any ``tribal implications'' as described in Executive
Order 13175, entitled Consultation and Coordination with Indian Tribal
Governments (65 FR 67249, November 6, 2000). Executive Order 13175,
requires EPA to develop an accountable process to ensure ``meaningful
and timely input by tribal officials in the development of regulatory
policies that have tribal implications.'' ``Policies that have tribal
implications'' is defined in the Executive Order to include regulations
that have ``substantial direct effects on one or more Indian tribes, on
the relationship between the Federal government and the Indian tribes,
or on the distribution of power and responsibilities between the
Federal government and Indian tribes.'' This rule will not have
substantial direct effects on tribal governments, on the relationship
between the Federal government and Indian tribes, or on the
distribution of power and responsibilities between the Federal
government and Indian tribes, as specified in Executive Order 13175.
Thus, Executive Order 13175 does not apply to this rule.
Because this rule has been exempted from review under Executive
Order 11866 due to its lack of significance, this rule is not subject
to Executive Order 13211, Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use (66 FR 28355,
May 22, 2001).

IX. 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 this final rule in the Federal Register. This final
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: August 28, 2001.
Peter Caulkins,
Acting Director, Registration Division, Office of Pesticide Programs.

Therefore, 40 CFR chapter I is amended as follows:

PART 180--[AMENDED]

1. The authority citation for part 180 continues to read as
follows:

Authority: 21 U.S.C. 321(q), 346(a) and 371.

2. Section 180.324 is amended by adding text to paragraph (b) to
read as follows:

Sec. 180.324 Bromoxynil, tolerances for residues.

* * * * *
(b) Section 18 emergency exemptions. Time-limited tolerances are
established for residues of the insecticide bromoxynil, 3,5-dibromo-4-
hydroxybenzonitrile in connection with use of the pesticide under
section 18 emergency exemptions granted by EPA. The tolerances will
expire and are revoked on the date specified in the following table:

------------------------------------------------------------------------
Expiration/
Commodity Parts per million revocation date
------------------------------------------------------------------------
Timothy, hay...................... 0.50 ppm 6/30/03
Timothy, forage................... 0.10 ppm 6/30/03
------------------------------------------------------------------------

[[Page 47403]]

* * * * *
[FR Doc. 01-22526 Filed 9-11-01; 8:45 am]
BILLING CODE 6560-50-S

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