[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