![[logo] US EPA](http://www.epa.gov/epafiles/images/logo_epaseal.gif){kind=logo}
Triclopyr; 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 5, 1997 (Volume 62, Number 172)]
[Rules and Regulations]
[Page 46888-46894]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr05se97-16]
-----------------------------------------------------------------------
ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
[OPP-300535; FRL-5738-8]
RIN 2070-AB78
Triclopyr; Pesticide Tolerances for Emergency Exemptions
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: This regulation establishes time-limited tolerances for
residues of triclopyr and its 3,5,6-trichloro-2-pyridinol metabolite in
or on fish at 0.2 ppm and shellfish at 5.0 ppm. This action is in
response to EPA's granting of an emergency exemption under section 18
of the Federal Insecticide, Fungicide, and Rodenticide Act authorizing
use of the pesticide on aquatic sites. This regulation establishes a
maximum permissible level for residues of triclopyr in these
commodities pursuant to section 408(l)(6) of the Federal Food, Drug,
and Cosmetic Act, as amended by the Food Quality Protection Act of
1996. These tolerances will expire and are revoked on December 31, 1998.
DATES: This regulation is effective September 5, 1997. Objections and
requests for hearings must be received by EPA on or before November 4,
1997.
ADDRESSES: Written objections and hearing requests, identified by the
docket control number, [OPP-300535], must be submitted to: Hearing
Clerk (1900), Environmental Protection Agency, Rm. M3708, 401 M St.,
SW., Washington, DC 20460. Fees accompanying objections and hearing
requests shall be labeled ``Tolerance Petition Fees'' and forwarded to:
EPA Headquarters Accounting Operations Branch, OPP (Tolerance Fees),
P.O. Box 360277M, Pittsburgh, PA 15251. A copy of any objections and
hearing requests filed with the Hearing Clerk identified by the docket
control number, [OPP-300535], must also be submitted to: Public
Information and Records Integrity Branch, Information Resources and
Services Division (7506C), Office of Pesticide Programs, Environmental
Protection Agency, 401 M St., SW., Washington, DC 20460. In person,
bring a copy of objections and hearing requests to Rm. 1132, CM #2,
1921 Jefferson Davis Hwy., Arlington, VA.
A copy of objections and hearing requests filed with the Hearing
Clerk may also be submitted electronically by sending electronic mail
(e-mail) to: opp-docket@epamail.epa.gov. Copies of objections and
hearing requests must be submitted as an ASCII file avoiding the use of
special characters and any form of encryption. Copies of objections and
hearing requests will also be accepted on disks in WordPerfect 5.1 file
format or ASCII file format. All copies of objections and hearing
requests in electronic form must be identified by the docket control
number [OPP-300535]. 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: Olga Odiott, Registration
Division 7505C, Office of Pesticide Programs, Environmental Protection
Agency, 401 M St., SW., Washington, DC 20460. Office location,
telephone number, and e-mail address: Crystal Mall #2, 1921 Jefferson
Davis Hwy., Arlington, VA, (703) 308-308-9363, e-mail:
odiott.olga@epamail.epa.gov.
SUPPLEMENTARY INFORMATION: EPA, on its own initiative, pursuant to
section 408(e) and (l)(6) of the Federal Food, Drug, and Cosmetic Act
(FFDCA), 21 U.S.C. 346a(e) and (l)(6), is establishing a time-limited
tolerances for residues of the herbicide triclopyr and its metabolite
3,5,6-trichloro-2-pyridinol, in or on fish at 0.2 part per million
(ppm) and shellfish at 5.0 ppm. These tolerances will expire and are
revoked on December 31, 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 FR 58135, November 13, 1996)(FRL-5572-9).
New section 408(b)(2)(A)(i) of the FFDCA allows EPA to establish a
tolerance (the legal limit for a pesticide chemical residue in or on a
food) only if EPA determines that the tolerance is ``safe.'' Section
408(b)(2)(A)(ii) defines ``safe'' to mean that ``there is a reasonable
certainty that no harm will result from aggregate exposure to the
pesticide chemical residue, including all anticipated dietary exposures
and all other exposures for which there is reliable information.'' This
includes exposure through drinking water and in residential settings,
but does not include occupational exposure. Section 408(b)(2)(C)
requires EPA to give special consideration to exposure of infants and
children to the pesticide chemical residue in establishing a tolerance
and to ``ensure that there is a reasonable certainty that no harm will
result to infants and children from aggregate exposure to the pesticide
chemical residue. . . .''
Section 18 of FIFRA authorizes EPA to exempt any Federal or State
agency from any provision of FIFRA, if EPA determines that ``emergency
conditions exist which require such exemption.'' This provision was not
amended by FQPA. EPA has established regulations governing such
emergency exemptions in 40 CFR part 166.
Section 408(l)(6) of the FFDCA requires EPA to establish a time-
limited tolerance or exemption from the requirement for a tolerance for
pesticide chemical residues in food that will result from the use of a
pesticide under an emergency exemption granted by EPA under section 18
of FIFRA. Such tolerances can be established without providing notice
or period for public comment.
Because decisions on section 18-related tolerances must proceed
before EPA reaches closure on several policy issues relating to
interpretation and implementation of the FQPA, EPA does not intend for
its actions on such tolerance to set binding precedents for the
application of section 408 and the new safety standard to other
tolerances and exemptions.
II. Emergency Exemption for Triclopyr on Aquatic Sites and FFDCA
Tolerances
The Applicants stated that the Purple loosestrife (Lythrum
salicaria), an exotic herbaceous perennial, if not controlled, will
have significant deleterious effects on the States' wetlands and
wildlife. The Purple loosestrife rapidly replaces native vegetation and
once established
[[Page 46889]]
is very difficult to control. As plant diversity diminishes, wildlife
species are displaced from the wetlands due to the loss of food sources
and nesting areas. The Purple loosestrife could render the wildlife
areas useless for the intended purposes, and the millions of dollars
that have been invested by the state and federal goverments would be
lost. Use of triclopyr will allow the States to selectively remove the
Purple loosestrife without harming desirable species. EPA has
authorized under FIFRA section 18 the use of triclopyr on aquatic sites
for control of the Purple loosestrife in North Dakota and Minnesota.
After having reviewed their submission, EPA concurs that emergency
conditions exist for these States.
As part of its assessment of this emergency exemption, EPA assessed
the potential risks presented by residues of triclopyr in or on fish
and shellfish. In doing so, EPA considered the new safety standard in
FFDCA section 408(b)(2), and EPA decided that the necessary tolerances
under FFDCA section 408(l)(6) would be consistent with the new safety
standard and with FIFRA section 18. Consistent with the need to move
quickly on the emergency 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 under section 408(e), as provided in section
408(l)(6). Although these tolerances will expire and are revoked on
December 31, 1998, under FFDCA section 408(l)(5), residues of the
pesticide not in excess of the amounts specified in the tolerances
remaining in or on fish and shellfish after that date will not be
unlawful, provided the pesticide is applied in a manner that was lawful
under FIFRA. EPA will take action to revoke these tolerances earlier if
any experience with, scientific data on, or other relevant information
on this pesticide indicate that the residues are not safe.
Because these tolerances are being approved under emergency
conditions EPA has not made any decisions about whether triclopyr meets
EPA's registration requirements for use on aquatic sites 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 triclopyr by a State for special local needs
under FIFRA section 24(c). Nor do these tolerances serve as the basis
for any State other than North Dakota and Minnesota to use this
pesticide on this crop under section 18 of FIFRA without following all
provisions of section 18 as identified in 40 CFR part 166. For
additional information regarding the emergency exemption for triclopyr,
contact the Agency's Registration Division at the address provided above.
III. Risk Assessment and Statutory Findings
EPA performs a number of analyses to determine the risks from
aggregate exposure to pesticide residues. First, EPA determines the
toxicity of pesticides based primarily on toxicological studies using
laboratory animals. These studies address many adverse health effects,
including (but not limited to) reproductive effects, developmental
toxicity, toxicity to the nervous system, and carcinogenicity. Second,
EPA examines exposure to the pesticide through the diet (e.g., food and
drinking water) and through exposures that occur as a result of
pesticide use in residential settings.
A. Toxicity
1. Threshold and non-threshold effects. For many animal studies, a
dose response relationship can be determined, which provides a dose
that causes adverse effects (threshold effects) and doses causing no
observed effects (the ``no-observed effect level'' or ``NOEL'').
Once a study has been evaluated and the observed effects have been
determined to be threshold effects, EPA generally divides the NOEL from
the study with the lowest NOEL by an uncertainty factor (usually 100 or
more) to determine the Reference Dose (RfD). The RfD is a level at or
below which daily aggregate exposure over a lifetime will not pose
appreciable risks to human health. An uncertainty factor (sometimes
called a ``safety factor'') of 100 is commonly used since it is assumed
that people may be up to 10 times more sensitive to pesticides than the
test animals, and that one person or subgroup of the population (such
as infants and children) could be up to 10 times more sensitive to a
pesticide than another. In addition, EPA assesses the potential risks
to infants and children based on the weight of the evidence of the
toxicology studies and determines whether an additional uncertainty
factor is warranted. Thus, an aggregate daily exposure to a pesticide
residue at or below the RfD (expressed as 100% or less of the RfD) is
generally considered acceptable by EPA. EPA generally uses the RfD to
evaluate the chronic risks posed by pesticide exposure. For shorter
term risks, EPA calculates a margin of exposure (MOE) by dividing the
estimated human exposure into the NOEL from the appropriate animal
study. Commonly, EPA finds MOEs lower than 100 to be unacceptable. This
100-fold MOE is based on the same rationale as the 100-fold uncertainty
factor.
Lifetime feeding studies in two species of laboratory animals are
conducted to screen pesticides for cancer effects. When evidence of
increased cancer is noted in these studies, the Agency conducts a
weight of the evidence review of all relevant toxicological data
including short-term and mutagenicity studies and structure activity
relationship. Once a pesticide has been classified as a potential human
carcinogen, different types of risk assessments (e.g., linear low dose
extrapolations or MOE calculation based on the appropriate NOEL) will
be carried out based on the nature of the carcinogenic response and the
Agency's knowledge of its mode of action.
2. Differences in toxic effect due to exposure duration. The
toxicological effects of a pesticide can vary with different exposure
durations. EPA considers the entire toxicity data base, and based on
the effects seen for different durations and routes of exposure,
determines which risk assessments should be done to assure that the
public is adequately protected from any pesticide exposure scenario.
Both short and long durations of exposure are always considered.
Typically, risk assessments include ``acute'', ``short-term'',
``intermediate term'', and ``chronic'' risks. These assessments are
defined by the Agency as follows.
Acute risk, by the Agency's definition, results from 1-day
consumption of food and water, and reflects toxicity which could be
expressed following a single oral exposure to the pesticide residues.
High end exposure to food and water residues are typically assumed.
Short-term risk results from exposure to the pesticide for a period
of 1-7 days, and therefore overlaps with the acute risk assessment.
Historically, this risk assessment was intended to address primarily
dermal and inhalation exposure which could result, for example, from
residential pesticide applications. However, since enaction of FQPA,
this assessment has been expanded to include both dietary and non-
dietary sources of exposure, and will typically consider exposure from
food, water, and residential uses when reliable data are available. In
this assessment, risks from average food and water exposure, and high-
end residential exposure, are aggregated. High-end exposures from all 3
sources
[[Page 46890]]
are not typically added because of the very low probability of this
occurring in most cases, and because the other conservative assumptions
built into the assessment assure adequate protection of public health.
However, for cases in which high-end exposure can reasonably be
expected from multiple sources (e.g. frequent and widespread homeowner
use in a specific geographical area), multiple high-end risks will be
aggregated and presented as part of the comprehensive risk assessment/
characterization. Since the toxicological endpoint considered in this
assessment reflects exposure over a period of at least 7 days, an
additional degree of conservatism is built into the assessment; i.e.,
the risk assessment nominally covers 1-7 days exposure, and the
toxicological endpoint/NOEL is selected to be adequate for at least 7
days of exposure. (Toxicity results at lower levels when the dosing
duration is increased.)
Intermediate-term risk results from exposure for 7 days to several
months. This assessment is handled in a manner similar to the short-
term risk assessment.
Chronic risk assessment describes risk which could result from
several months to a lifetime of exposure. For this assessment, risks
are aggregated considering average exposure from all sources for
representative population subgroups including infants and children.
B. Aggregate Exposure
In examining aggregate exposure, FFDCA section 408 requires that
EPA take into account available and reliable information concerning
exposure from the pesticide residue in the food in question, residues
in other foods for which there are tolerances, residues in groundwater
or surface water that is consumed as drinking water, and other non-
occupational exposures through pesticide use in gardens, lawns, or
buildings (residential and other indoor uses). Dietary exposure to
residues of a pesticide in a food commodity are estimated by
multiplying the average daily consumption of the food forms of that
commodity by the tolerance level or the anticipated pesticide residue
level. The Theoretical Maximum Residue Contribution (TMRC) is an
estimate of the level of residues consumed daily if each food item
contained pesticide residues equal to the tolerance. In evaluating food
exposures, EPA takes into account varying consumption patterns of major
identifiable subgroups of consumers, including infants and children.The
TMRC is a ``worst case'' estimate since it is based on the assumptions
that food contains pesticide residues at the tolerance level and that
100% of the crop is treated by pesticides that have established
tolerances. If the TMRC exceeds the RfD or poses a lifetime cancer risk
that is greater than approximately one in a million, EPA attempts to
derive a more accurate exposure estimate for the pesticide by
evaluating additional types of information (anticipated residue data
and/or percent of crop treated data) which show, generally, that
pesticide residues in most foods when they are eaten are well below
established tolerances.
Percent of crop treated estimates are derived from federal and
private market survey data. Typically, a range of estimates are
supplied and the upper end of this range is assumed for the exposure
assessment. By using this upper end estimate of percent of crop
treated, the Agency is reasonably certain that exposure is not
understated for any significant subpopulation group. Further, regional
consumption information is taken into account through EPA's computer-
based model for evaluating this pesticide, the most highly exposed
population subgroup (non-nursing infants < 1 year old) was not
regionally based.
IV. Aggregate Risk Assessment and Determination of Safety
Consistent with section 408(b)(2)(D), EPA has reviewed the
available scientific data and other relevant information in support of
this action, EPA has sufficient data to assess the hazards of triclopyr
and to make a determination on aggregate exposure, consistent with
section 408(b)(2), for a time-limited tolerances for residues of
triclopyr and its metabolite 3,5,6-trichloro-2-pyridinol in or on fish
at 0.2 ppm and shellfish at 5.0 ppm. EPA's assessment of the dietary
exposures and risks associated with establishing these tolerances
follows.
A. Toxicological Profile
EPA has evaluated the available toxicity data and considered its
validity, completeness, and reliability as well as the relationship of
the results of the studies to human risk. EPA has also considered
available information concerning the variability of the sensitivities
of major identifiable subgroups of consumers, including infants and
children. The nature of the toxic effects caused by triclopyr are
discussed below.
1. Acute toxicity. The developmental NOEL of 30 mg/kg/day from a
rabbit developmental study was recommended for the acute dietary risk
assessment. At the lowest effect level (LEL) of 100 mg/kg/day, there
were decreased number of live fetuses, increased fetal deaths, reduced
ossification of sternebrae and digital bones, and increased percentage
of fetuses with 13 ribs. This risk assessment will evaluate acute
dietary risk to pregnant females age 13 and older.
2. Short - and intermediate - term toxicity. Based on the
available data, the Agency has determined that short- and intermediate-
term dermal and inhalation risk assessments are not required. A
systemic NOEL of 1,000 mg/kg/day, the highest dose tested, (HDT) was
determined in a 21-day dermal toxicity study in rabbits. The LC50 from
the acute inhalation study was determined to be £ 2.6 mg/L
(Toxicity Category IV).
3. Chronic toxicity. EPA has established the RfD for triclopyr at
0.05 milligrams/kilogram/day (mg/kg/day). This RfD is based on a
reproductive toxicity study in rats with a NOEL of 5 mg/kg/day using an
Uncertainty Factor of 100. At the next higher dose level (HDL) of 25
mg/kg/day, an increased incidence of degeneration of the proximal
tubules of the kidney was observed in P1 and P2 parents of both sexes.
On this basis, the RfD was calculated to be 0.05 mg/kg/day.
4. Carcinogenicity. The Agency's Cancer Peer Review Committee
(CPRC) concluded that triclopyr should be classified as ``Group D
chemical'' - not classifiable as to human carcinogenicity. A cancer
risk assessment is not required.
B. Exposures and Risks
1. From food and feed uses. Tolerances have been established (40
CFR 180.417) for the residues of triclopyr in or on a variety of raw
agricultural commodities. and its metabolites 3,5,6-trichloro-2-
pyridinol and 2-methoxy-3,5,6-trichloropyridine, expressed as
triclopyr, in or on rice grain (0.3 ppm), rice straw (10.0 ppm), grass
forage (500 ppm), and grass hay (500 ppm). Tolerances for triclopyr and
the two metabolites have been established for poultry meat, fat, and
meat byproducts (except kidney) at 0.1 ppm and eggs at 0.05 ppm.
Tolerances for triclopyr and the metabolite 3,5,6-trichloro-2-pyridinol
have been established for meat, fat, and meat byproducts (except liver
and kidney) of cattle, goats, hogs, horses, and sheep at 0.05 ppm;
liver and kidney of cattle, goats, hogs, horses, and sheep at 0.5 ppm;
and milk at 0.01 ppm. Risk assessments were conducted by EPA to assess
dietary exposures and risks from triclopyr as follows:
[[Page 46891]]
i. Acute exposure and risk. Acute dietary risk assessments are
performed for a food-use pesticide if a toxicological study has
indicated the possibility of an effect of concern occurring as a result
of a one day or single exposure. The acute dietary (food only) risk
assessment assumed tolerance level residues and 100% crop treated
values. For pregnant females age 13 years and older, the dietary (food
only) MOE was estimated as 2500. This estimate should be viewed as a
conservative risk estimate. Refinement of the risk assessment using
anticipated residue values and percent crop-treated data would result
in a lower acute dietary exposure estimate.
ii. Chronic exposure and risk. The chronic dietary risk assessment
assumed that 100% of fish and shellfish and all other commodities
having triclopyr tolerances will contain triclopyr residues and those
residues would be at the level of the tolerance, which result in an
overestimate of human dietary exposure. Thus, in making a safety
determination for these tolerances, EPA is taking into account this
conservative exposure assessment. The existing triclopyr tolerances
(published, pending, and including the necessary Section 18 tolerances)
result in a TMRC that is equivalent to percentages of the RfD that
range from 0. 9% for nursing infants < 1 year old, to 2.6% for non-
nursing infants < 1 year old.
2. From drinking water. Based on available data used in EPA's
assessment of environmental risk, triclopyr is not persistent in water.
The degradation product 3,5,6-trichloro-2-pyridinol (TCP) is mobile.
There are no established Maximum Contaminant Levels for residues of
triclopyr in drinking water. No health advisory levels for triclopyr in
drinking water have been established. Triclopyr has been detected in 5
wells out of 379 wells tested in four states. The concentrations ranged
from 0.006 to 0.58 ppb. For surface water, at the maximum application
rate of 12.12 lbs. a.i./A, the maximum concentration was 364 ppb and
the 56-day concentration was 233 ppb.
The drinking water risk assessment was based on surface water
exposure, which is considered to represent the worst case scenario in
comparison to ground water. The maximum concentration of triclopyr
residues (364 ppb) was used to calculate the acute exposures for adult
females and children. The 56-day concentration (233 ppb) was used to
calculate the chronic exposures for adult females and children. It was
assumed that adult females consume 2 liters of water a day and children
consume 1 liter of water a day.
i. Acute exposure and risk. The exposure for adult females was
estimated as 1.2 x 10-2 mg/kg/day. The exposure for children
was estimated as 3.6 x 10-2 mg/kg/day. The corresponding MOE
values were 2500 for pregnant females and 825 for children. These
values do not exceed the Agency's level of concern.
ii. Chronic exposure and risk. The chronic exposure was estimated
as 7.7 x 10-3 mg/kg/day for adult females and 2.3 x
10-2 mg/kg/day for children. These chronic exposures to
triclopyr from drinking water will utilize 15% of the RfD for adult
females and 46% of the RfD for children. The Agency concludes that that
there is a reasonable certainty that no harm will result from drinking
water exposures to triclopyr.
3. From non-dietary exposure. Triclopyr is currently registered for
use on outdoor non-food sites such as turf and ornamentals. These uses
may result in non-occupational exposures. However, the available data
indicate no evidence of significant toxicity and a reasonable certainty
that no harm will result from non-occupational exposures to triclopyr
residues.
4. Cumulative exposure to substances with common mechanism of
toxicity. Section 408(b)(2)(D)(v) requires that, when considering
whether to establish, modify, or revoke a tolerance, the Agency
consider ``available information'' concerning the cumulative effects of
a particular pesticide's residues and ``other substances that have a
common mechanism of toxicity.'' The Agency believes that ``available
information'' in this context might include not only toxicity,
chemistry, and exposure data, but also scientific policies and
methodologies for understanding common mechanisms of toxicity and
conducting cumulative risk assessments. For most pesticides, although
the Agency has some information in its files that may turn out to be
helpful in eventually determining whether a pesticide shares a common
mechanism of toxicity with any other substances, EPA does not at this
time have the methodologies to resolve the complex scientific issues
concerning common mechanism of toxicity in a meaningful way. EPA has
begun a pilot process to study this issue further through the
examination of particular classes of pesticides. The Agency hopes that
the results of this pilot process will increase the Agency's scientific
understanding of this question such that EPA will be able to develop
and apply scientific principles for better determining which chemicals
have a common mechanism of toxicity and evaluating the cumulative
effects of such chemicals. The Agency anticipates, however, that even
as its understanding of the science of common mechanisms increases,
decisions on specific classes of chemicals will be heavily dependent on
chemical specific data, much of which may not be presently available.
Although at present the Agency does not know how to apply the
information in its files concerning common mechanism issues to most
risk assessments, there are pesticides as to which the common mechanism
issues can be resolved. These pesticides include pesticides that are
toxicologically dissimilar to existing chemical substances (in which
case the Agency can conclude that it is unlikely 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 triclopyr 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,
triclopyr 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 triclopyr has a common mechanism of toxicity
with other substances.
C. Aggregate Risks and Determination of Safety for U.S. Population
1. Acute risk. For the population subgroup of concern, pregnant
females age 13 and older, the Agency estimated an MOE of 1250 for the
acute aggregate dietary risk (food + water) from exposures to triclopyr
residues. Residential exposure was considered to be negligible.
Therefore, the aggregate exposure is not expected to exceed the
Agency's level of concern.
2. Chronic risk. Using the TMRC exposure assumptions described
above, EPA has concluded that the percentage of the RfD that will be
utilized by aggregate exposures [food + water] to residues of triclopyr
ranges from 16% [1% for food and 15% for water] to 48% [46% for water
and 2% for food] for the U.S. population. The major identifiable
subgroup with the highest aggregate exposure is non-nursing infants <1
year old (discussed below). There are no chronic exposure scenarios for
non-dietary uses of triclopyr which would
[[Page 46892]]
contribute to the aggregate risk. EPA generally has no concern for
exposures below 100% of the RfD because the RfD represents the level at
or below which daily aggregate dietary exposure over a lifetime will
not pose appreciable risks to human health. EPA concludes that there is
a reasonable certainty that no harm will result from aggregate exposure
to triclopyr residues.
3. Short- and intermediate-term risk. Short- and intermediate-term
aggregate exposure takes into account chronic dietary food and water
(considered to be a background exposure level) plus indoor and outdoor
residential exposure. Although there is potential for outdoor
residential exposures, the Agency has determined that short- and
intermediate-term risk assessments are not required. The available data
indicate no evidence of significant toxicity and a reasonable certainty
that no harm will result from these exposures to triclopyr residues.
D. Aggregate Cancer Risk for U.S. Population
The Agency's CPRC concluded that triclopyr should be classified as
``Group D chemical'' - not classifiable as to human carcinogenicity.
E. Aggregate Risks and Determination of Safety for Infants and Children
1. Safety factor for infants and children-- i. In general. In
assessing the potential for additional sensitivity of infants and
children to residues of triclopyr, EPA considered data from
developmental toxicity studies in the rat and rabbit and a two-
generation reproduction study in the rat. The developmental toxicity
studies are designed to evaluate adverse effects on the developing
organism resulting from maternal pesticide exposure during gestation.
Reproduction studies provide information relating to effects from
exposure to the pesticide on the reproductive capability of mating
animals and data on systemic toxicity.
FFDCA section 408 provides that EPA shall apply an additional
tenfold margin of safety for infants and children in the case of
threshold effects to account for pre-and post-natal toxicity and the
completeness of the database unless EPA determines that a different
margin of safety will be safe for infants and children. Margins of
safety are incorporated into EPA risk assessments either directly
through use of a MOE analysis or through using uncertainty (safety)
factors in calculating a dose level that poses no appreciable risk to
humans. EPA believes that reliable data support using the standard 100-
fold safety factor (usually 100 for combined inter- and intra-species
variability) and not the additional tenfold safety factor when EPA has
a complete data base under existing guidelines and when the severity of
the effect in infants or children or the potency or unusual toxic
properties of a compound do not raise concerns regarding the adequacy
of the standard safety factor.
ii. Developmental toxicity studies-- a. Rats: The maternal
(systemic) NOEL was 100 mg/kg/day, based on increased salivation and
mortality at the lowest observed effect level (LOEL) of 300 mg/kg/day.
The developmental (fetal) NOEL was 100 mg/kg/day, based on skeletal
anomalies at the LOEL of 300 mg/kg/day.
b. Rabbits. The maternal (systemic) NOEL was 30 mg/kg/day, based on
increased mortality and cesearean section observations at the LOEL of
100 mg/kg/day. The developmental (fetal) NOEL was 30 mg/kg/day, based
on skeletal anomalies and variants at the LOEL of 100 mg/kg/day.
iii. Reproductive toxicity study-- Rats. In the 2-generation
reproductive toxicity study in rats, the parental (systemic) NOEL was
2.5 mg/kg/day, based on an increased incidence of degeneration of the
proximal tubules of the kidney, observed in P1 and P2 parents of both
sexes at the LOEL of 25 mg/kg/day. The developmental (pup) NOEL was 25
mg/kg/day based on decreased litter size, decreased body weight, and
decreased survival at the LOEL of 250 mg/kg/day.
iv. Pre- and post-natal sensitivity. The toxicological data base
for evaluating pre- and post-natal toxicity for triclopyr is complete
with respect to current data requirements. There are no pre- or post-
natal toxicity concerns for infants and children, based on the results
of the rat and rabbit developmental toxicity studies and the 2-
generation rat reproductive toxicity study. The developmental studies
in rats and rabbits both have the maternal NOELs and LOELs at the same
doses as the developmental NOELs and LOELs, respectively, and
demonstrate that no pre-natal extra sensitivity is present. However,
based on the developmental effects observed in rabbits, an acute
dietary risk assessment was performed for women age 13 and older. The
MOE was estimated as 2500.
The 2-generation rat reproduction study did not demonstrate any
pre- or post natal extra sensivity for infants and children, since the
developmental/reproductive (pup) findings occurred at 250 mg/kg/day in
the presence of severe maternal toxicity.
v. Conclusion. The EPA concludes that reliable data support use of
the standard 100-fold margin of exposure/uncertainty factor and that an
additional margin/factor is not needed to protect infants and children.
2. Acute risk. The acute aggregate dietary MOE (food + water) was
calculated to be 1250 for females age 13 and older (accounts for both
maternal and fetal exposure), the population subgroup of concern. The
MOE calculations were based on the developmental NOEL in rabbits of 30
mg/kg/day. This risk assessment assumed 100% crop-treated with
tolerance level residues on all treated crops consumed, resulting in a
significant over-estimate of dietary exposure. The large acute dietary
MOE calculated for females age 13 and older provides assurance that
there is a reasonable certainty of no harm for infants and children
from exposures to triclopyr.
3. Chronic risk. Using the conservative exposure assumptions
described above, EPA has concluded that the chronic aggregate (food +
water) exposure to triclopyr for infants and children occupies 48% of
the RfD. EPA generally has no concern for exposures below 100% of the
RfD because the RfD represents the level at or below which daily
aggregate dietary exposure over a lifetime will not pose appreciable
risks to human health. There are no chronic exposure scenarios for non-
dietary uses of triclopyr which would contribute to the aggregate risk.
Taking into account the completeness and reliability of the toxicity
data and this conservative exposure assessment, EPA concludes that
there is a reasonable certainty that no harm will result to infants and
children from aggregate exposure to triclopyr residues.
V. Other Considerations
A. Metabolism In Plants and Animals
The nature of the residue in fish and shellfish is adequately
understood. The residues of concern in fish and shellfish are the
parent triclopyr and its metabolite 3,5,6-trichloro-2-pyridinol. The
residues specified in 40 CFR 180.417 for fish and shellfish are the
parent compound triclopyr and its two metabolites 3,5,6-trichloro-2-
pyridinol and 2-methoxy-3,5,6-trichloropyridine. However, the Agency's
Metabolism Committee determined that the residue to be regulated in
plants, milk, poultry, and eggs is parent triclopyr only. The residues
to be regulated in meat and meat byproducts are triclopyr and 3,5,6-
trichloro-2-pyridinol .
[[Page 46893]]
B. Analytical Enforcement Methodology
Adequate enforcement methodologies (gas chromatography with ECD)
are available in PAM, Vol. II, Methods I and II for plant and animal
commodities to enforce the tolerance expression.
C. Magnitude of Residues
Residues of triclopyr and its regulated metabolites are not
expected to exceed 0.2 ppm in fish and 5.0 ppm in shellfish as a result
of this Section 18 use. Provided irrigation with treated water is
restricted for two weeks (product label restriction), measurable
residues in irrigated crops are unlikely. Secondary residues in animal
commodities are not expected to exceed existing tolerances as a result
of this Section 18 use.
D. International Residue Limits
There are no Codex proposals (step 6 or above), Canadian limits, or
Mexican limits for triclopyr on fish and shellfish.
E. Rotational Crop Restrictions.
Residues in rotational crops are not a concern for this use of
triclopyr on aquatic sites since crops will not be rotated into the
treated aquatic sites.
VI. Conclusion
Therefore, time-limited tolerances are established for residues of
triclopyr and its metabolite 3,5,6-trichloro-2-pyridinol in /on fish at
0.2 ppm and shellfish at 5.0 ppm.
VII. Objections and Hearing Requests
The new FFDCA section 408(g) provides essentially the same process
for persons to ``object'' to a tolerance regulation issued by EPA under
new section 408(e) and (l)(6) as was provided in the old section 408
and in section 409. However, the period for filing objections is 60
days, rather than 30 days. EPA currently has procedural regulations
which govern the submission of objections and hearing requests. These
regulations will require some modification to reflect the new law.
However, until those modifications can be made, EPA will continue to
use those procedural regulations with appropriate adjustments to
reflect the new law.
Any person may, by November 4, 1997, file written objections to any
aspect of this regulation and may also request a hearing on those
objections. Objections and hearing requests must be filed with the
Hearing Clerk, at the address given above (40 CFR 178.20). A copy of
the objections and/or hearing requests filed with the Hearing Clerk
should be submitted to the OPP docket for this rulemaking. The
objections submitted must specify the provisions of the regulation
deemed objectionable and the grounds for the objections (40 CFR
178.25). Each objection must be accompanied by the fee prescribed by 40
CFR 180.33(i). If a hearing is requested, the objections must include a
statement of the factual issues on which a hearing is requested, the
requestor's contentions on such issues, and a summary of any evidence
relied upon by the requestor (40 CFR 178.27). A request for a hearing
will be granted if the Administrator determines that the material
submitted shows the following: There is genuine and substantial issue
of fact; there is a reasonable possibility that available evidence
identified by the requestor would, if established, resolve one or more
of such issues in favor of the requestor, taking into account
uncontested claims or facts to the contrary; and resolution of the
factual issues in the manner sought by the requestor would be adequate
to justify the action requested (40 CFR 178.32). Information submitted
in connection with an objection or hearing request may be claimed
confidential by marking any part or all of that information as
Confidential Business Information (CBI). Information so marked will not
be disclosed except in accordance with procedures set forth in 40 CFR
part 2. A copy of the information that does not contain CBI must be
submitted for inclusion in the public record. Information not marked
confidential may be disclosed publicly by EPA without prior notice.
VIII. Public Record
EPA has established a record for this rulemaking under docket
control number [OPP-300535] (including any comments and data submitted
electronically). A public version of this record, including printed,
paper versions of electronic comments, which does not include any
information claimed as CBI, is available for inspection from 8:30 a.m.
to 4 p.m., Monday through Friday, excluding legal holidays. The public
record is located in Room 1132 of the Public Information and Records
Integrity Branch, Information Resources and Services Division (7506C),
Office of Pesticide Programs, Environmental Protection Agency, Crystal
Mall #2, 1921 Jefferson Davis Hwy., Arlington, VA.
Electronic comments may be sent directly to EPA at:
opp-docket@epamail.epa.gov.
Electronic comments must be submitted as an ASCII file avoiding the
use of special characters and any form of encryption.
The official record for this rulemaking, as well as the public
version, as described above will be kept in paper form. Accordingly,
EPA will transfer any copies of objections and hearing requests
received electronically into printed, paper form as they are received
and will place the paper copies in the official rulemaking record which
will also include all comments submitted directly in writing. The
official rulemaking record is the paper record maintained at the
Virginia address in ``ADDRESSES'' at the beginning of this document.
IX. Regulatory Assessment Requirements
This final rule establishes time-limited tolerances under FFDCA
section 408(l)(6). The Office of Management and Budget (OMB) has
exempted these types of actions from review under Executive Order
12866, entitled Regulatory Planning and Review (58 FR 51735, October 4,
1993). This final rule does not contain any information collections
subject to OMB approval under the Paperwork Reduction Act (PRA), 44
U.S.C. 3501 et seq., or impose any enforceable duty or contain any
unfunded mandate as described under Title II of the Unfunded Mandates
Reform Act of 1995 (UMRA) (Pub. L. 104-4). Nor does it require any
prior consultation as specified by Executive Order 12875, entitled
Enhancing the Intergovernmental Partnership (58 FR 58093, October 28,
1993), or special considerations as required by Executive Order 12898,
entitled Federal Actions to Address Environmental Justice in Minority
Populations and Low-Income Populations (59 FR 7629, February 16, 1994),
or require OMB review in accordance with Executive Order 13045,
entitled Protection of Children from Environmental Health Risks and
Safety Risks (62 FR 19885, April 23, 1997).
In addition, since these tolerances and exemptions that are
established under FFDCA section 408 (l)(6), such as the tolerances in
this final rule, do not require the issuance of a proposed rule, the
requirements of the Regulatory Flexibility Act (RFA) (5 U.S.C. 601 et
seq.) do not apply. Nevertheless, the Agency has previously assessed
whether establishing tolerances, exemptions from tolerances, raising
tolerance levels or expanding exemptions might adversely impact small
entities and concluded, as a generic matter, that there is no adverse
economic impact. The factual basis for the Agency's generic
certification for tolerance acations published on May 4, 1981 (46 FR
24950), and was provided to the
[[Page 46894]]
Chief Counsel for Advocacy of the Small Business Administration.
X. Submission to Congress and the General Accounting Office
Under 5 U.S.C. 801(a)(1)(A), as added by the Small Business
Regulatory Enforcement Fairness Act of 1996, the Agency has submitted a
report containing this rule and other required information to the U.S.
Senate, the U.S. House of Representatives, and the Comptroller General
of the General Accounting Office prior to publication of this rule in
today's Federal Register. This is not a ``major rule'' as defined by 5
U.S.C. 804(2).
List of Subjects in 40 CFR Part 180
Environmental protection, Administrative practice and procedure,
Agricultural commodities, Pesticides and pests, Reporting and
recordkeeping requirements.
Dated: August 22, 1997.
James Jones,
Acting Director, Registration Division, Office of Pesticide Programs.
Therefore, 40 CFR chapter I is amended as follows:
PART 180--[AMENDED]
1. The authority citation for part 180 continues to read as follows:
Authority: 21 U.S.C. 346a and 371.
2. Section 180.417 is amended as follows:
a. By adding a heading to paragraph (a) and redesignating the text
of paragraph (a) as paragraph (a)(1).
b. By redesignating paragraph (b) as paragraph (a)(2).
c. By adding a new paragraph (b).
d. By adding headings and reserving paragraphs (c) and (d).
Section 180.417, as amended, reads as follows:
Sec. 180.417 Triclopyr; tolerances for residues.
(a) General. * * *
(b) Section 18 emergency exemptions. Time-limited tolerances are
established for the combined residues of the herbicide triclopyr
((3,5,6-trichloro-2-pyridinyl)oxy)acetic acid and its metabolite 3,5,6-
trichloro-2-pyridinol in connection with use of the pesticide under
section 18 emergency exemptions granted by EPA. The tolerance is
specified in the following table. The tolerances will expire and are
revoked on the dates specified in the following table:
------------------------------------------------------------------------
Expiration/
Commodity Parts per revocation
million date
------------------------------------------------------------------------
Fish.......................................... 0.2 12/31/98
Shellfish..................................... 5.0 12/31/98
------------------------------------------------------------------------
(c) Tolerances with regional registrations. [Reserved]
(d) Indirect or inadvertent residues. [Reserved]
[FR Doc. 97-23683 Filed 9-4-97; 8:45 am]
BILLING CODE 6560-50-F