[Federal Register Volume 62, Number 239 (Friday, December 12, 1997)]
[Rules and Regulations]
[Pages 65369-65376]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-32548]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
[OPP-300590; FRL-5759-5]
RIN 2070-AB78
Chlorothalonil; Pesticide Tolerances for Emergency Exemptions
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
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SUMMARY: This regulation establishes a time-limited tolerance for
residues of chlorothalonil in or on ginseng. 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 ginseng. This regulation establishes a maximum
permissible level for residues of chlorothalonil and its metabolite 4-
hydroxy-2,5,6-trichloroisophthalonitrile, expressed as chlorothalonil,
in this food commodity pursuant to section 408(l)(6) of the Federal
Food, Drug, and Cosmetic Act, as amended by the Food Quality Protection
Act of 1996. The tolerance will expire and is revoked on December 31,
1998.
DATES: This regulation is effective December 12, 1997. Objections and
requests for hearings must be received by EPA on or before February 10,
1998.
ADDRESSES: Written objections and hearing requests, identified by the
docket control number, [OPP-300590], 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-300590], must also be submitted to: Public
Information and Records Integrity Branch, Information Resources and
Services Division (7502C), Office of Pesticide Programs, Environmental
Protection Agency, 401 M St., SW., Washington, DC 20460. In person,
bring a copy of objections and hearing requests to Rm. 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 5.1/6.1
file format or ASCII file format. All copies of objections and hearing
requests in electronic form must be identified by the docket control
number [OPP-300590]. 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) 308-9363, 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 tolerance for
residues of the fungicide chlorothalonil and its 4-hydroxy-2,5,6-
trichloroisophthalonitrile metabolite, expressed as chlorothalonil, in
or on ginseng at 0.10 parts per million (ppm). This tolerance will
expire and is revoked on December 31, 1998. EPA will publish a document
in the Federal Register to remove the revoked tolerance 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.
[[Page 65370]]
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 Chlorothalonil on Ginseng and FFDCA
Tolerances
The state of Wisconsin availed itself of the authority to declare a
crisis exemption to use chlorothalonil to control the ginseng leaf and
stem blight caused by Alternaria panax. A. panax may cause substantial
losses of ginseng yield if not controlled. Specific emergency
exemptions have been granted for the use of mancozeb for several years
based on loss of efficacy of iprodione due to development of resistance
in the pathogen to the latter fungicide. The state argues that while
mancozeb affords good protection during typical years, during years of
very heavy precipitation, as in 1996 and 1997, mancozeb is inadequate
because it is easily washed off plants by rain. In this respect, the
state claims, chlorothalonil provides superior control during very
rainy summers. EPA has authorized under FIFRA section 18 the use of
chlorothalonil on ginseng for control of leaf and stem blight in
Wisconsin.
As part of its assessment of this emergency exemption, EPA assessed
the potential risks presented by residues of chlorothalonil in or on
ginseng. In doing so, EPA considered the new safety standard in FFDCA
section 408(b)(2), and EPA decided that the necessary tolerance under
FFDCA section 408(l)(6) would be consistent with the 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 this tolerance without notice and opportunity
for public comment under section 408(e), as provided in section
408(l)(6). Although this tolerance will expire and is revoked on
December 31, 1998, under FFDCA section 408(l)(5), residues of the
pesticide not in excess of the amounts specified in the tolerance
remaining in or on ginseng 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 this tolerance earlier if any
experience with, scientific data on, or other relevant information on
this pesticide indicate that the residues are not safe.
Because this tolerance is being approved under emergency conditions
EPA has not made any decisions about whether chlorothalonil meets EPA's
registration requirements for use on ginseng or whether a permanent
tolerance for this use would be appropriate. Under these circumstances,
EPA does not believe that this tolerance serves as a basis for
registration of chlorothalonil by a state for special local needs under
FIFRA section 24(c). Nor does this tolerance serve as the basis for any
state other than Wisconsin 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 chlorothalonil, 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,
[[Page 65371]]
and therefore overlaps with the acute risk assessment. Historically,
this risk assessment was intended to address primarily dermal and
inhalation exposure which could result, for example, from residential
pesticide applications. However, since enaction of FQPA, this
assessment has been expanded to include both dietary and non-dietary
sources of exposure, and will typically consider exposure from food,
water, and residential uses when reliable data are available. In this
assessment, risks from average food and water exposure, and high-end
residential exposure, are aggregated. High-end exposures from all three
sources are not typically added because of the very low probability of
this occurring in most cases, and because the other conservative
assumptions built into the assessment assure adequate protection of
public health. However, for cases in which high-end exposure can
reasonably be expected from multiple sources (e.g., frequent and
widespread homeowner use in a specific geographical area), multiple
high-end risks will be aggregated and presented as part of the
comprehensive risk assessment/characterization. Since the toxicological
endpoint considered in this assessment reflects exposure over a period
of at least 7 days, an additional degree of conservatism is built into
the 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 ground water
or surface water that is consumed as drinking water, and other non-
occupational exposures through pesticide use in gardens, lawns, or
buildings (residential and other indoor uses). Dietary exposure to
residues of a pesticide in a food commodity are estimated by
multiplying the average daily consumption of the food forms of that
commodity by the tolerance level or the anticipated pesticide residue
level. The Theoretical Maximum Residue Contribution (TMRC) is an
estimate of the level of residues consumed daily if each food item
contained pesticide residues equal to the tolerance. In evaluating food
exposures, EPA takes into account varying consumption patterns of major
identifiable subgroups of consumers, including infants and children.The
TMRC is a ``worst case'' estimate since it is based on the assumptions
that food contains pesticide residues at the tolerance level and that
100% of the crop is treated by pesticides that have established
tolerances. If the TMRC exceeds the RfD or poses a lifetime cancer risk
that is greater than approximately one in a million, EPA attempts to
derive a more accurate exposure estimate for the pesticide by
evaluating additional types of information (anticipated residue data
and/or percent of crop treated data) which show, generally, that
pesticide residues in most foods when they are eaten are well below
established tolerances.
Percent of crop treated estimates are derived from Federal and
private market survey data. Typically, a range of estimates are
supplied and the upper end of this range is assumed for the exposure
assessment. By using this upper end estimate of percent of crop
treated, the Agency is reasonably certain that exposure is not
understated for any significant subpopulation group. Further, regional
consumption information is taken into account through EPA's computer-
based model for evaluating the exposure of significant subpopulations
including several regional groups, to pesticide residues. For this
pesticide, the most highly exposed population subgroup (children 1 to 6
years old) was not regionally based.
IV. Aggregate Risk Assessment and Determination of Safety
Consistent with section 408(b)(2)(D), EPA has reviewed the
available scientific data and other relevant information in support of
this action, EPA has sufficient data to assess the hazards of
chlorothalonil and to make a determination on aggregate exposure,
consistent with section 408(b)(2), for a time-limited tolerance for
residues of chlorothalonil and its metabolite 4-hydroxy-2,5,6-
trichloroisophthalonitrile, expressed as chlorothalonil, in or on
ginseng at 0.10 ppm. EPA's assessment of the dietary exposures and
risks associated with establishing the tolerance 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 chlorothalonil are
discussed below. The nature of the toxic effects caused by
hexachlorobenzene (HCB), a contaminant of chlorothalonil, are also
discussed.
1. Acute toxicity. The lowest observed effect level (LOEL) of 175
milligrams/kilogram/day (mg/kg/day) (only dose tested) from a 3-month
rat study was used for evaluating acute dietary risk from
chlorothalonil to all subgroups. The LOEL was based on renal and
gastric lesions observed within 4 days of testing. An uncertainty
factor of 300 was recommended since a LOEL instead of a NOEL was used
for the assessment.
No acute dietary endpoints have been identified for HCB.
2. Short - and intermediate - term toxicity. The NOEL of 600 mg/
kg/day highest dose tested (HDT) from a 21-day dermal toxicity study in
male Fischer 344 rats was recommended to assess risks from short and
intermediate-term exposures to residues of chlorothalonil.
There is no toxicological endpoint identified for short and
intermediate-term exposure to HCB.
3. Chronic toxicity. EPA has established the RfD for chlorothalonil
at 0.018 mg/kg/day. This RfD is based on a 2-year dog feeding study
with a NOEL of 1.8 mg/kg/day and an uncertainty factor of 100 (based on
increased urinary bilirubin levels and kidney vacuolated epithelium at
3.5 mg/kg/day).
The EPA has established the RfD for HCB at 0.0008 mg/kg/day. This
RfD is based on the NOEL of 0.08 mg/kg/day from a 130-week feeding
study in rats. At the LEL of 0.29 mg/kg/day, there was hepatic
centrilobular basophilic chromogenesis. An uncertainty factor of 100
was used to account for inter-species extrapolation and intra-species
variability.
4. Carcinogenicity. The OPP Cancer Peer Review Committee (CPRC)
classified chlorothalonil as a Group B2 (probable human carcinogen)
chemical with a Q1* = 7.66 x 10-3 (mg/kg/
day)-1. The classification was based on
[[Page 65372]]
forestomach tumors in mice and renal tumors in rats. The Q1*
was based upon female rat renal (adenoma and/or carcinoma) tumor rates.
A 3/4 scaling factor was used to determine the Q1* from the
rat data. HCB, an impurity in chlorothalonil, is also classified as a
Group B2 chemical (probable human carcinogen) with a Q1* =
1.02 (mg/kg/day)-1. The classification was based on positive
results in hamsters and rats.
B. Exposures and Risks
1. From food and feed uses. Tolerances have been established (40
CFR 180.275) for residues of chlorothalonil and its metabolite 4-
hydroxy-2,5,6-trichloroisophthalonitrile, expressed as chlorothalonil,
in or on a variety of raw agricultural commodities at levels ranging
from 0.05 ppm in cocoa beans and bananas, edible pulp to 15 ppm in
celery and papayas. There are no established tolerances on meat, milk,
poultry and eggs. Risk assessments were conducted by EPA to assess
dietary exposures and risks from chlorothalonil as presented below.
Ginseng is not presently represented in the Dietary Risk Evaluation
System (DRES) data files because of very low consumption in the U.S.
Thus, the dietary exposure analysis does not include a contribution for
ginseng. The consumption of ginseng is not expected to significantly
alter exposure.
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 1 day or single exposure. The acute dietary (food only) risk
assessment used tolerance level residues ( published and pending
tolerances included). The resulting high-end exposure estimate of 0.2
mg/kg/day results in a dietary (food only) MOE of 1,500 for infants < 1
year old and children 1-6 years old. This should be viewed as a
conservative risk estimate.
ii. Chronic exposure and risk. For the chronic dietary risk
assessment, the Agency used anticipated residue data. The anticipated
residues based on existing chlorothalonil tolerances (published and
pending) result in an anticipated residue contribution (ARC) that is
equivalent to percentages of the RfD that range from 19.8% for non-
nursing infants to 85.8% for children 1 to 6 years old.
Estimates for HCB result in an ARC that is equivalent to
percentages of the RfD that range from 0.01% for non-nursing infants to
0.05% for children 1 to 6 years old. Residues of HCB were estimated to
be present at a level not exceeding 0.05% (the maximum, allowed in
chlorothalonil formulations) of the residues of chlorothalonil.
2. From drinking water. Based on available data used in EPA's
assessment of environmental risk, chlorothalonil is not persistent and
is moderately mobile. Health advisory levels for chlorothalonil in
drinking water have been established as follows: for a 10 kg child, the
one day finalized level and the long term level is 0.2 mg/L; for a 70
kg adult, the long term is 0.5 kg/L. No lifetime health advisory level
has been established for chlorothalonil, but the Office of Drinking
Water estimates that a long term average chlorothalonil concentration
of 150 g/L would correspond to an additional lifetime
carcinogenic risk of 10-4. Consequently, a concentration of 1.5
g/L would correspond to a lifetime carcinogenic risk of
10-6. Chlorothalonil is not currently regulated under the
Safe Drinking Water Act (SDWA), therefore water supply systems are not
required to sample and analyze for it. The intermediate soil/water
partitioning of chlorothalonil should make the primary treatment
processes employed by most surface water source supply systems at least
partially effective in removing it.
Ground water. Degradates (metabolites) of chlorothalonil, not
chlorothalonil itself, have been found in ground water in the states of
New York, Massachusetts, Florida, Maine, and California (U.S. HED,
1993). The reported metabolites (SDS-46851, SDS-47525, SDS-3701, and
SDS-19221) were measured at the highest combined concentration of
approximately 16 ppb in New York's Suffolk County (Long Island) in
1981. It is not clear how the use of chlorothalonil in New York
compares to use in other areas, but it is expected that the levels of
chlorothalonil metabolites detected in the ground water in New York are
unrepresentatively high compared to the country as a whole. A small-
scale ground water monitoring study is underway, and will give the
Agency a more quantitative measure of the ground water contamination
potential.
Surface water. Chlorothalonil can contaminate surface water at
application via spray drift. The intermediate soil/water partitioning
of chlorothalonil indicates that its concentration in suspended and
bottom sediment will be substantially greater than its concentration in
water.
The following surface water label advisory is required for
chlorothalonil:
Chlorothalonil can contaminate surface water through spray
drift. Under some conditions, chlorothalonil may also have a high
potential for runoff into surface water (via both dissolution in
runoff water and adsorption to eroding soil), for several weeks to
months post-application. These include poorly draining or wet soils
with readily visible slopes toward adjacent surface waters,
frequently flooded areas, areas over-laying extremely shallow ground
water, areas with in-field canals or ditches that drain to surface
water, areas not separated from adjacent surface waters with
vegetated filter strips, and highly erodible soils.
The South Florida Water Management District (SFWMD; Miles and
Pfeuffer 1994) summarized chlorothalonil detections in samples
collected every 2 to 3 months from 27 surface water sites within the
SFWMD from November 1988 through November 1993. Approximately 810
samples were collected. Chlorothalonil was detected in 25 samples at
concentrations ranging from 0.003 to 0.035 g/L (0.003 ppb to
0.035 ppb).
Exposures and risks. The Agency does not have sufficient data to
complete a comprehensive drinking water risk assessment for the
potential of chlorothalonil and its degradates to contaminate ground
water. For this drinking water risk assessment the Agency assumed that
the metabolites of chlorothalonil have the same toxicity as the parent
chlorothalonil and used the highest measured concentration levels to
calculate acute and chronic risks from drinking water exposures to
residues of chlorothalonil. The Agency also assumed that adults
weighing 70 kg consume 2 liters of drinking water per day while
children weighing 10 kg drink 1 liter. The acute drinking water risk
was calculated by dividing the LOEL identified for acute dietary risk
assessment by the exposure from drinking water sources. The chronic
risk for drinking water was calculated by comparing exposure from
drinking water sources to the appropriate RfD.
The following risk assessments should be considered as worst case
scenarios. As the necessary data are received, the risk assessments
will be reviewed and evaluated based on the new data.
i. Acute exposure and risk-- Ground water. In order to calculate
acute drinking water risk, the highest concentration detected in ground
water (16 ppb) was compared to the acute dietary exposure LOEL of 175
mg/kg/day. Acute exposures were estimated to be 0.0016 mg/kg/day for
children and 0.00046 mg/kg/day for adults. The corresponding MOEs were
estimated as 109,375 for children and 380,435 for adults.
Surface water. The available surface water monitoring information
was used to perform an exposure assessment of
[[Page 65373]]
surface water as a drinking water source. The highest measured
concentration (0.035 g/L) and the acute dietary LOEL were used
to estimate exposures and risks. Exposures were estimated to be
0.000035 mg/kg/day for children and 0.00001 mg/kg/day for adults. The
corresponding MOEs were estimated as 5,000,000 for children and
17,500,000 for adults.
The large MOEs provide a reasonable certainty of no harm from the
potential exposures associated with chlorothalonil in water.
Acute drinking water risk to HCB was not calculated since no acute
dietary endpoint has been identified for HCB.
ii. Chronic exposure and risk-- Ground water. The highest
concentration detected in ground water (16 ppb) and the RfD for
chlorothalonil were used to estimate exposures and risks. The Agency
estimated that chronic dietary risks from drinking water will utilize
8% of the RfD for children and 2% of the RfD for adults.
Surface water. The highest measured concentration (0.035
g/L) from the available surface water monitoring data and the
RfD for chlorothalonil were used to estimate exposures and risks. The
Agency estimated that chronic dietary risks from surface water
exposures to residues of chlorothalonil will utilize < 1% of the RfD
for both children and adults.
To estimate the chronic dietary risk from exposures to HCB,
concentrations for chlorothalonil were assumed to be contaminated with
0.05% HCB. The resulting concentration was compared to the RfD for HCB
(0.0008 mg/kg/day). The Agency estimated that chronic dietary risks
from surface water exposures to residues of HCB will utilize < 1% of
the RfD for both children and adults.
3. From non-dietary exposure. Chlorothalonil is currently
registered for use on the following residential non-food sites: turf,
lawn, trees, grasses, bulbs, plants, and shrubs. Indoor uses include:
paints, coatings, adhesives, wood treatments, and resin emulsions.
The Agency currently lacks residential-related exposure data to
complete a comprehensive residential risk assessment for many
pesticides, including chlorothalonil.
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).
Chlorothalonil (tetrachloroisophthalonitrile) is a member of the
substituted aromatics class of pesticides (George W. Ware, The
Pesticide Book, 4th edition, page 144, Thomson Publications, 1994).
Other members of this class include pentachloronitrobenzene (PCNB) and
2,6-dichloro-4-nitroaniline (dicloran, DCNA).
EPA does not have, at this time, available data to determine
whether chlorothalonil has a common mechanism of toxicity with other
substances or how to include this pesticide in a cumulative risk
assessment. For the purposes of this tolerance action, therefore, EPA
has not assumed that chlorothalonil 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 overall U.S. population the calculated MOE
value (food) is 2,000 for chlorothalonil. For acute drinking water
risk, the calculated MOE for adults, based on ground water monitoring
data, is 380,435. The acute aggregate risk for general U.S. population
is 1,163 (175 mg/kg/day 0.15046 mg/kg/day). The acute
aggregate risk for chlorothalonil for all population subgroups is below
HED's level of concern.
2. Chronic risk. Using the ARC exposure assumptions described
above, EPA has concluded that aggregate exposure to chlorothalonil from
food and water will utilize 46.5% (44.5% from food +
2% from water) of the RfD for the U.S. population. The
aggregate exposure to HCB from food and water will utilize
1.03% (0.03% from food + 1% from water) of the
RfD for the U.S. population. The major identifiable subgroup with the
highest aggregate exposure is children 1 to 6 year old. EPA generally
has no concern for exposures below 100% of the RfD because the RfD
represents the level at or below which daily aggregate dietary exposure
over a lifetime will not pose appreciable risks to human health. EPA
concludes that there is a reasonable certainty that no harm will result
from aggregate exposure to chlorothalonil and HCB 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.
Based on the registered uses of chlorothalonil short and
intermediate-term exposure scenarios may exist. However, the Agency
currently lacks sufficient residential-related exposure data to
complete a comprehensive residential risk assessment for
chlorothalonil.
D. Aggregate Cancer Risk for U.S. Population
The cancer risk from food uses of chlorothalonil (a B2 carcinogen
with a Q1* of 7.66 x 10-3 (mg/kg/
day)-1) for the general U.S. population was estimated as 1.1
x 10-6 (upper bound). The calculation was based on ARC
estimates. EPA used all the published, pending and new uses for
chlorothalonil
[[Page 65374]]
and substracted the risk figures from consumption of meat and milk
products. Residues of chlorothalonil per se are not expected to
transfer from feed items to meat and milk, but residues of the 4-
hydroxy metabolite (which is not of carcinogenic concern) could occur
in these commodities. Thus, there is no carcinogenic risk attributable
to chlorothalonil from its use on livestock feed items.
The dietary (food) cancer risk from HCB (a B2 carcinogen with a
Q1* of 1.02 (mg/kg/day)-1) for the general U.S.
population was estimated as 3.6 x 10-7 (upper bound). The
concentrations for chlorothalonil were assumed to be contaminated with
0.05% HCB. The calculation was based on ARC estimates and all the
published, pending and new uses for chlorothalonil.
The drinking water cancer risk from exposure to chlorothalonil
residues was estimated as 2 x 10-7 for children and 7 x
10-8 for adults. These estimates are based on the highest
measured concentration from the available surface water monitoring
data. Only metabolites of chlorothalonil have been found in ground
water. These metabolites are not of carcinogenic concern, therefore an
assessment of the cancer risks associated with dietary exposures to
chlorothalonil from ground water sources was not conducted. The
drinking water cancer risk from exposure to HCB residues was estimated
as 1 x 10-7 for children and 5 x 10-9 for adults.
The concentrations for chlorothalonil were assumed to be contaminated
with 0.05% HCB.
For the drinking water risk assessment the Agency assumed that
water comes from the same source containing the same contaminant level
and is consumed throughout a 36-year period. This is extremely
conservative, since it is likely that frequency and amounts of
chlorothalonil used vary widely over this time, and most of the U.S.
population moves at some time and does not live in the same area,
drinking from the same water source for a 36-year period. Therefore,
the risk to both adults and children from drinking water is likely an
over-estimate.
The Agency concludes that the aggregate (food + water) cancer risks
from exposures to chlorothalonil and HCB do not exceed the levels of
concern.
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 chlorothalonil, EPA considered data from
developmental toxicity studies in the rat and rabbit and a 2-generation
reproduction study in the rat. The developmental toxicity studies are
designed to evaluate adverse effects on the developing organism
resulting from maternal pesticide exposure during gestation.
Reproduction studies provide information relating to effects from
exposure to the pesticide on the reproductive capability of mating
animals and data on systemic toxicity.
FFDCA section 408 provides that EPA shall apply an additional
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 data base unless EPA determines that a different
margin of safety will be safe for infants and children. Margins of
safety are incorporated into EPA risk assessments either directly
through use of a MOE analysis or through using uncertainty (safety)
factors in calculating a dose level that poses no appreciable risk to
humans. EPA believes that reliable data support using the standard 100-
fold safety factor (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-- Rats. The maternal (systemic)
NOEL was 100 mg/kg/day, based on increased mortality and reduced weight
gain at the LOEL of 400 mg/kg/day. The developmental (fetal) NOEL was
100 mg/kg/day, based on increase in total resorptions and resorptions
per dam with related increase in postimplantation loss at the LOEL of
400 mg/kg/day.
Rabbits. The maternal (systemic) NOEL was 10 mg/kg/day, based on
reductions in weight gain and food consumption during dosing at the
LOEL of 20 mg/kg/day. The developmental (fetal) NOEL was 20 mg/kg/day
(HDT).
iii. Reproductive toxicity study-- Rats. In the 2-generation
reproductive toxicity study in rats, the maternal (systemic) NOEL was
less than 38 mg/kg/day lowest dose tested (LDT), based on hyperplasia
of renal and forestomach tissues at the LOEL of 38 mg/kg/day. The
reproductive/developmental (pup) NOEL was 115 mg/kg/day, based on
decreased pup weight on day 21 of lactation and a suggestive increase
in the incidence of neonatal renal pelvis dilation in the
F1a generation at the LOEL of 234 mg/kg/day.
iv. Pre- and post-natal sensitivity. The toxicological data base
for evaluating pre- and post-natal toxicity for chlorothalonil 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. In these studies, the fetal
or pup NOELs occur at or above the maternal NOELs indicating that there
is no extra-sensitivity for infants and children.
v. Conclusion. Based on the above, HED concludes that reliable data
support use of the standard uncertainty factor of 100 and that an
additional safety factor is not needed to protect infants and children.
2. Acute risk. The acute dietary MOE (food) was calculated to be
1,500 for infants (<1 year), 1,500 for children (1-6 years), and 3,000
for females 13+ years (accounts for both maternal and fetal exposure).
The acute aggregate MOE (food and water) for the most highly exposed
subpopulation (children 1 - 6 years old) was calculated to be 868.
These MOE calculations were based on the systemic LOEL in rats of 175
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 13+ years provides assurance that there is a
reasonable certainty of no harm for both females 13+ years and the pre
and post-natal development of infants.
3. Chronic risk. Using the conservative exposure assumptions
described above, EPA has concluded that aggregate dietary (food +
water) exposure to chlorothalonil will utilize percentages of the RfD
that range from 27.8% (19.8% for food + 8% for water) for nursing
infants, up to 93.8% (85.8% for food + 8% for water) for children 1-6
years old.
The percentage of the RfD that will be utilized by aggregate
exposure food + water to residues of HCB ranges from 1.01%
for nursing infants, up to 1.05% for children 1-6 years old.
EPA generally has no concern for exposures below 100% of the RfD
because the RfD represents the level at or below which daily aggregate
dietary exposure over a lifetime will not pose appreciable risks to
human health. EPA concludes that there is a reasonable certainty that
no harm will result to infants and children from aggregate exposure to
chlorothalonil residues.
[[Page 65375]]
V. Other Considerations
A. Metabolism In Plants and Animals
The nature of the residue in plants and animals is adequately
understood. The residues of concern are chlorothalonil and its
metabolite 4-hydroxy-2,5,6-trichloroisophthalonitrile is an impurity in
chlorothalonil products.
B. Analytical Enforcement Methodology
Adequate enforcement methodology (gas chromatography-electron
capture detection) is available in PAM II (Method I) to enforce the
tolerance expression.
C. Magnitude of Residues
Residues of chlorothalonil and its metabolite 4-hydroxy-2,5,6-
trichloroisophthalonitrile are not expected to exceed 0.10 ppm in/on
ginseng as a result of this section 18 use. Secondary residues are not
expected in animal commodities as no feed items are associated with
this section 18 use.
D. International Residue Limits
There are no Codex proposals, Canadian limits, or Mexican limits
for chlorothalonil on ginseng.
E. Rotational Crop Restrictions
EPA has determined that rotational crop studies will not be
required for uses of pesticides on ginseng.
VI. Conclusion
Therefore, the tolerance is established for chlorothalonil and its
metabolite 4-hydroxy-2,5,6-trichloroisophthalonitrile (expresed as
chlorothalonil) in ginseng at 0.10 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 February 10, 1998, file written objections to
any aspect of this regulation and may also request a hearing on those
objections. Objections and hearing requests must be filed with the
Hearing Clerk, at the address given above (40 CFR 178.20). A copy of
the objections and/or hearing requests filed with the Hearing Clerk
should be submitted to the OPP docket for this rulemaking. The
objections submitted must specify the provisions of the regulation
deemed objectionable and the grounds for the objections (40 CFR
178.25). Each objection must be accompanied by the fee prescribed by 40
CFR 180.33(i). If a hearing is requested, the objections must include a
statement of the factual issues on which a hearing is requested, the
requestor's contentions on such issues, and a summary of any evidence
relied upon by the requestor (40 CFR 178.27). A request for a hearing
will be granted if the Administrator determines that the material
submitted shows the following: There is genuine and substantial issue
of fact; there is a reasonable possibility that available evidence
identified by the requestor would, if established, resolve one or more
of such issues in favor of the requestor, taking into account
uncontested claims or facts to the contrary; and resolution of the
factual issues in the manner sought by the requestor would be adequate
to justify the action requested (40 CFR 178.32). Information submitted
in connection with an objection or hearing request may be claimed
confidential by marking any part or all of that information as CBI.
Information so marked will not be disclosed except in accordance with
procedures set forth in 40 CFR part 2. A copy of the information that
does not contain CBI must be submitted for inclusion in the public
record. Information not marked confidential may be disclosed publicly
by EPA without prior notice.
VIII. Public Docket
EPA has established a record for this rulemaking under docket
control number [OPP-300590] (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 (7502C),
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 a time-limited tolerance under FFDCA
section 408(l)(d). 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 on the basis of a petition under FFDCA section 408 (l)(6),
such as the tolerance in this final rule, do not require the issuance
of a proposed rule, the requirements of the Regulatory Flexibility Act
(RFA) (5 U.S.C. 601 et seq.) do not apply. 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
[[Page 65376]]
the Agency's generic certification for tolerance acations published on
May 4, 1981 (46 FR 24950), and was provided to the Chief Counsel for
Advocacy of the Small Business Administration.
X. Submission to Congress and the 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: December 1, 1997.
Peter Caulkins,
Acting Director, Registration Division, Office of Pesticide Programs.
Therefore, 40 CFR chapter I is amended as follows:
PART 180--[AMENDED]
1. The authority citation for part 180 continues to read as
follows:
Authority : 21 U.S.C. 346a and 371.
2. In Sec. 180.275, by adding a heading to paragraph (a); by
redesignating paragraph (b) as paragraph (c) and adding a heading; by
adding new paragraph (b); and by adding and reserving paragraph (d)
with a heading to read as follows:
Sec. 180.275 Chlorothalonil; tolerances for residues.
(a) General . * * *
(b) Section 18 emergency exemptions. Time-limited tolerances are
established for chlorothalonil and its metabolite 4-hydroxy-2,5,6-
trichloroisophthalonitrile (expresed as chlorothalonil) in connection
with use of the pesticide under the section 18 emergency exemptions
granted by EPA. The tolerances will expire and are revoked on the dates
specified in the following table:
----------------------------------------------------------------------------------------------------------------
Expiration/revocation
Commodity Parts per million date
----------------------------------------------------------------------------------------------------------------
Ginseng....................................................... 0.10 12/31/98
----------------------------------------------------------------------------------------------------------------
(c) Tolerances with regional registrations. * * *
(d) Indirect or inadvertent residues. [Reserved]
[FR Doc. 97-32548 Filed 12-11-97; 8:45 am]
BILLING CODE 6560-50-F