[Federal Register Volume 62, Number 172 (Friday, September 5, 1997)]
[Rules and Regulations]
[Pages 46888-46894]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-23683]


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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.

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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: [email protected]. Copies of objections and 
hearing requests must be submitted as an ASCII file avoiding the use of 
special characters and any form of encryption. Copies of objections and 
hearing requests will also be accepted on disks in WordPerfect 5.1 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: 
[email protected].

SUPPLEMENTARY INFORMATION: EPA, on its own initiative, pursuant to 
section 408(e) and (l)(6) of the Federal Food, Drug, and Cosmetic Act 
(FFDCA), 21 U.S.C. 346a(e) and (l)(6), is establishing 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:
    [email protected].


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