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cryolite (Kryocide) Time-Limited Pesticide Tolerance 11/97



ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[OPP-300586; FRL-5756-5]
RIN 2070-AB78

 
Fluorine Compounds; Time-Limited Pesticide Tolerance

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This regulation establishes a time-limited tolerance for 
residues of the insecticidal fluorine compounds cryolite and/or 
synthetic cryolite (sodium aluminum fluoride) in or on the raw 
agricultural commodity (RAC) potatoes and in the processed animal feed 
commodity, potato waste. A petition requesting these tolerances was 
submitted by The Cryolite Task Force under the Federal Food Drug and 
Cosmetic Act (FFDCA) as amended by the Food Quality Protection Act of 
1996 (Pub. L. 104-170). The tolerance will expire on November 21, 2001.

DATES: This regulation is effective December 5, 1997. Objections and 
requests for hearings must be received by EPA on or before February 3, 
1998.

ADDRESSES: Written objections and hearing requests, identified by the 
document control number, OPP-300586, 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 
document control number, [OPP-300586], must 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, Crystal 
Mall #2, 1921 Jefferson Davis Hwy., Arlington, VA 22202.
    A copy of objections and hearing requests filed with the Hearing 
Clerk may also be submitted electronically by sending electronic mail 
(e-mail) to: OPP-docket@epamail.epa.gov. Copies of objections and 
hearing requests must be submitted as an ASCII file avoiding the use of 
special characters and any form of encryption. Copies of objections and 
hearing requests will also be accepted on disks in WordPerfect 5.1 file 
format or ASCII file format. All copies of objections and hearing 
requests in electronic form must be identified by the docket number 
[OPP-300586]. 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: Jacqueline Mosby, 
Environmental Scientist, 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) 305-6792, e-mail: mosby-romney.jackie2epamail.epa.gov.

SUPPLEMENTARY INFORMATION: EPA issued notices as follows regarding 
petitions for pesticide tolerances for insecticidal fluorine compounds 
in or on potatoes and in the processed animal feed, potato waste.
    1. March 23, 1989 (54 FR 12009); PP 9F3739; filing notice;
    2. April 3, 1991 (56 FR 13643); PP 1F3959 and FAP 1H5604; filing 
notice.
    3. May 5, 1993 (58 FR 26687); PP 9F3739 and FAP 1H5604; final rule 
for time-limited tolerances.
    4. May 8, 1996 (61 FR 20781) (FRL-5362-6); PP 9F3739 and FAP 
1H5604); proposed rule for permanent tolerances.
    The Agency did not publish a final rule establishing permanent 
tolerances prior to the enactment of the Food Quality and Protection 
Act (FQPA) of 1996. Because of new procedures under FQPA, The Cryolite 
Task Force, c/o Gowan Company, P.O. Box 5569, Yuma, AZ 85336 was 
required to submit a notice of filing requesting issuance of these 
tolerances in compliance with FQPA.
    In the Federal Register of March 12, 1997 (62 FR 11437) EPA issued 
a notice of filing pursuant to section 408 of the Federal Food, Drug 
and Cosmetic Act (FFDCA), 21 U.S.C. 346a(e) announcing the filing of a 
pesticide petition (PP) for tolerance by The Cryolite Task Force. This 
notice contained a summary of the petition prepared by The Cryolite 
Task Force.
    The petition requested that 40 CFR 180.145 be amended by 
establishing tolerances for residues of the insecticidal fluorine 
compounds cryolite and synthetic cryolite in or on potatoes at 2.0 
parts per million (ppm) and processed potato waste at 22.0 ppm. These 
tolerances will expire on November 21, 2001.

I. Risk Assessment and Statutory Findings

    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

[[Page 64295]]

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. . . .''
    EPA performs a number of analyses to determine the risks from 
aggregate exposure to pesticide residues. First, EPA determines the 
toxicity of pesticides based primarily on toxicological studies using 
laboratory animals. These studies address many adverse health effects, 
including (but not limited to) reproductive effects, developmental 
toxicity, toxicity to the nervous system, and carcinogenicity. Second, 
EPA examines exposure to the pesticide through the diet (e.g., food and 
drinking water) and through exposures that occur as a result of 
pesticide use in residential settings.

A. Toxicity

    1. Threshold and non-threshold effects. For many animal studies, a 
dose response relationship can be determined, which provides a dose 
that causes adverse effects (threshold effects) and doses causing no 
observed effects (the ``no-observed effect level'' or ``NOEL'').
    Once a study has been evaluated and the observed effects have been 
determined to be threshold effects, EPA generally divides the NOEL from 
the study with the lowest NOEL by an uncertainty factor (usually 100 or 
more) to determine the Reference Dose (RfD). The RfD is a level at or 
below which daily aggregate exposure over a lifetime will not pose 
appreciable risks to human health. An uncertainty factor (sometimes 
called a ``safety factor'') of 100 is commonly used since it is assumed 
that people may be up to 10 times more sensitive to pesticides than the 
test animals, and that one person or subgroup of the population (such 
as infants and children) could be up to 10 times more sensitive to a 
pesticide than another. In addition, EPA assesses the potential risks 
to infants and children based on the weight of the evidence of the 
toxicology studies and determines whether an additional uncertainty 
factor is warranted. Thus, an aggregate daily exposure to a pesticide 
residue at or below the RfD (expressed as 100% or less of the RfD) is 
generally considered acceptable by EPA. EPA generally uses the RfD to 
evaluate the chronic risks posed by pesticide exposure. For shorter 
term risks, EPA calculates a margin of exposure (MOE) by dividing the 
estimated human exposure into the NOEL from the appropriate animal 
study. Commonly, EPA finds MOEs lower than 100 to be unacceptable. This 
100-fold MOE is based on the same rationale as the 100-fold uncertainty 
factor.
    Lifetime feeding studies in two species of laboratory animals are 
conducted to screen pesticides for cancer effects. When evidence of 
increased cancer is noted in these studies, the Agency conducts a 
weight of the evidence review of all relevant toxicological data 
including short-term and mutagenicity studies and structure activity 
relationship. Once a pesticide has been classified as a potential human 
carcinogen, different types of risk assessments (e.g., linear low dose 
extrapolations or MOE calculation based on the appropriate NOEL) will 
be carried out based on the nature of the carcinogenic response and the 
Agency's knowledge of its mode of action.
    2. Differences in toxic effect due to exposure duration. The 
toxicological effects of a pesticide can vary with different exposure 
durations. EPA considers the entire toxicity data base, and based on 
the effects seen for different durations and routes of exposure, 
determines which risk assessments should be done to assure that the 
public is adequately protected from any pesticide exposure scenario. 
Both short and long durations of exposure are always considered. 
Typically, risk assessments include ``acute,'' ``short-term,'' 
``intermediate term,'' and ``chronic'' risks. These assessments are 
defined by the Agency as follows.
    Acute risk, by the Agency's definition, results from 1-day 
consumption of food and water, and reflects toxicity which could be 
expressed following a single oral exposure to the pesticide residues. 
High end exposure to food and water residues are typically assumed.
    Short-term risk results from exposure to the pesticide for a period 
of 1-7 days, and therefore overlaps with the acute risk assessment. 
Historically, this risk assessment was intended to address primarily 
dermal and inhalation exposure which could result, for example, from 
residential pesticide applications. However, since enaction of FQPA, 
this assessment has been expanded to include both dietary and non-
dietary sources of exposure, and will typically consider exposure from 
food, water, and residential uses when reliable data are available. In 
this assessment, risks from average food and water exposure, and high-
end residential exposure, are aggregated. High-end exposures from all 3 
sources are not typically added because of the very low probability of 
this occurring in most cases, and because the other conservative 
assumptions built into the assessment assure adequate protection of 
public health. However, for cases in which high-end exposure can 
reasonably be expected from multiple sources (e.g. frequent and 
widespread homeowner use in a specific geographical area), multiple 
high-end risks will be aggregated and presented as part of the 
comprehensive risk assessment/characterization. Since the toxicological 
endpoint considered in this assessment reflects exposure over a period 
of at least 7 days, an additional degree of conservatism is built into 
the assessment; i.e., the risk assessment nominally covers 1-7 days 
exposure, and the toxicological endpoint/NOEL is selected to be 
adequate for at least 7 days of exposure. (Toxicity results at lower 
levels when the dosing duration is increased.)
    Intermediate-term risk results from exposure for 7 days to several 
months. This assessment is handled in a manner similar to the short-
term risk assessment.
    Chronic risk assessment describes risk which could result from 
several months to a lifetime of exposure. For this assessment, risks 
are aggregated considering average exposure from all sources for 
representative population subgroups including infants and children.

B. Aggregate Exposure

    In examining aggregate exposure, FFDCA section 408 requires that 
EPA take into account available and reliable information concerning 
exposure from the pesticide residue in the food in question, residues 
in other foods for which there are tolerances, residues in groundwater 
or surface water that is consumed as drinking water, and other non-
occupational exposures through pesticide use in gardens, lawns, or 
buildings (residential and other indoor uses). Dietary exposure to 
residues of a pesticide in a food commodity are estimated by 
multiplying the average daily consumption of the food forms of that 
commodity by the tolerance level or the anticipated pesticide residue 
level. The Theoretical Maximum Residue Contribution (TMRC) is an 
estimate of the level of residues consumed daily if each food item 
contained pesticide residues equal to the tolerance. In evaluating food 
exposures, EPA takes into account varying consumption patterns of major 
identifiable subgroups of consumers, including infants and children. 
The TMRC is a ``worst case'' estimate since it is based on the 
assumptions that food contains pesticide residues at the tolerance 
level and that 100% of the crop is treated by pesticides that have 
established

[[Page 64296]]

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.

II. 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 cryolite 
and to make a determination on aggregate exposure, consistent with 
section 408(b)(2), for a time-limited tolerance for residues of 
cryolite on potatoes at 2.0 ppm, and processed potato waste at 22.0 
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 cryolite are 
discussed below.
    1.  Acute toxicity studies. Oral, dermal, and inhalation studies 
place cryolite in toxicity category III, for acute dermal and in 
category IV for acute oral, and inhalation. No effects are observed in 
a skin irritation study, the eye irritation study shows it to be a 
moderate irritant to the eyes; and results of the dermal sensitization 
study shows it to be a non-sensitizer.
    2. Subchronic toxicity studies. i. A 28-day range-finding feeding 
study conducted with cryolite in rats at dose levels of 0, 250, 500, 
1,000, 2,000, 4,000, 10,000, 25,000 and 50,000 ppm in the diet 
(representing approximately 0, 25, 50, 100, 200, 400, 1,000, 2,500 and 
5,000 milligrams/kilograms/day) (mg/kg/day) with the only compound 
related effect being a change in coloration and physical property of 
the teeth.
    The NOEL was not determined. The LOEL is 250 ppm (25 mg/kg/day) 
based on dental fluorosis.
    ii. A 90-day rat feeding study conducted with cryolite at dose 
levels of 0, 50, 5,000, and 50,000 ppm (corresponding to 0, 3.8, 399.2 
and 4172.3 mg/kg/day in males and 0, 4.5, 455.9 and 4758.1 mg/kg/day in 
females).
    The NOEL is 50 ppm (3.8 mg/kg/day) for effects other than fluoride 
accumulation. The LOEL is 5,000 ppm (399.2 mg/kg/day) based on lesions 
observed in the stomach. Fluoride accumulated at all dose levels.
    iii. A 90-day dog feeding study conducted with cryolite at dose 
levels of 0, 500, 10,000, and 50,000 ppm (corresponding to 0, 17, 368 
and 1692 mg/kg/day).
    The NOEL is 10,000 ppm (368 mg/kg/day). The LOEL is 50,000 ppm 
(1,692 mg/kg/day) for effects other than fluoride accumulation. 
Fluoride accumulation occurred at all dose levels.
    3. Chronic/carcinogenicity studies.  i. A 2-year rat bioassay 
conducted by the National Toxicology Program (NTP) using sodium 
fluoride as the test material at dose levels of 0, 25, 100, and 175 
ppm, in water, representing 0, 1.3, 5.2 and 8.6 mg/kg/day in males and 
0, 1.3, 5.5 and 9.5 mg/kg/day in females.
    Osteosarcoma of the bone was only observed in one male in the 100 
ppm group and in three males in the 175 ppm group. NTP considers this 
to be equivocal evidence of carcinogenicity in male F344/N rats. The 
NOEL is less than 25 ppm (1.3 mg/kg/day). The LOEL is 25 ppm (1.3 mg/
kg/day) based on mottling of teeth, dentine incisor dysplasia, 
increased serum, urine and bone fluoride levels in males and females 
and incisor odontoblast and incisor ameloblast degeneration in males. 
There was ``equivocal evidence'' of carcinogenic activity in male rats 
and ``no evidence'' of carcinogenic activity in female rats.
    The NTP study utilizing sodium fluoride as the test material in 
lieu of cryolite or synthetic cryolite satisfies the guideline study 
requirement for both the rodent chronic feeding study and the rat 
carcinogenicity study. Fluoride has been identified as the residue of 
toxicological concern in cryolite and synthetic cryolite and the 
available data show that these compounds act as free fluoride.
    ii. A 2-year mouse bioassay conducted by the NTP utilizing sodium 
fluoride as the test material at dose levels of 0, 25, 100, and 175 
ppm, in water, representing 0, 2.4, 9.6 and 16.7 mg/kg/day in males and 
0, 2.8, 11.3 and 18.8 mg/kg/day in females.
    The NOEL is less than 25 ppm (2.4 mg/kg/day). The LOEL is 25 ppm 
(2.4 mg/kg/day) based on attrition of the teeth in males, discoloration 
and mottling of the teeth in males and females and increased bone 
fluoride in both sexes. There was ``no evidence'' of carcinogenic 
activity in male and female mice.
    This study utilizing sodium fluoride in lieu of cryolite or 
synthetic cryolite as the test material satisfies the guideline study 
requirement for a mouse carcinogenicity study for the reason described 
above under item 3.i.
    iii. A 1-year chronic dog feeding study conducted with Cryolite at 
dose levels of 0, 3,000, 10,000 and 30,000 ppm, representing 0, 95, 366 
and 1,137 mg/kg/day in males and 0, 105, 387 and 1,139 mg/kg/day in 
females (in terms of fluoride the doses are 0, 51, 198, and 614 mg F/
kg/day for males and 0, 57, 209 and 615 mg F/kg/day for females).
    The NOEL (in terms of Cryolite) is less than 3,000 ppm (95 mg/kg/
day in males and 105 mg/kg/day in females). The LOEL is 3,000 ppm (95 
mg/kg/day) based on increases in emesis, nucleated cells in males, 
renal lesions and a decrease in urine specific gravity in females.
    4. Other studies/documents. i. Mutagenicity studies including an 
Ames test (negative) at dose levels of 167, 500, 1670, 5,000, 7,500 and 
10,000 ug/plate; an in vitro assay in human lymphocytes (negative) at 
100, 500, and 1,000 g/ml; and an unscheduled DNA synthesis 
study in rat hepatocytes (negative) at dose levels up to and including 
50 g/ml.
    ii. Drinking water Criteria Document on Fluoride. Fluoride has been 
identified as the residue of toxicological concern in cryolite and 
synthetic cryolite and the available data show that these compounds 
which are approximately 52.8% fluoride, act as free fluoride.
    The EPA Office of Drinking Water issued a Drinking Water Criteria 
Document on Fluoride (October 21, 1985) which presents summaries of 
experimental and clinical data on the health effects of fluoride in 
animals and humans. In general, the health effects of fluoride (F) 
include dental fluorosis and skeletal fluorosis.

B. Toxicological Endpoints

    1. Acute toxicity. Based on the available toxicity data, EPA has 
determined that cryolite does not exhibit any adverse health effects 
occurring as a result of a one day or single dietary or non-dietary 
exposure.
    2. Short and intermediate-term toxicity. Based on the available 
data, EPA has determined that cryolite does not exhibit any adverse 
heath effects occurring as a result of short- or intermediate-term 
dietary and non-dietary exposure.

[[Page 64297]]

    3. Chronic toxicity. Rather than the establishment of the 
traditional Reference Dose (RfD), a weight-of-the-evidence risk 
assessment was determined by the Agency to be a more appropriate 
approach for the assessment of the dietary exposure to fluoride 
residues as a result of agricultural uses of cryolite for the following 
reasons:
    i. National and international regulatory organizations (U.S. EPA 
Office of Water, U.S. DHHS, the Canadian Government, and the World 
Health Organization) have assessed potential health risks from exposure 
to fluoride. The endpoints and estimated effect levels documented by 
these organizations are similar.
    ii. The U.S. Surgeon General (Koop, 1984 and Elders, 1994) has 
recommended a guideline level of exposure that should provide an 
adequate ``margin of safety'' based on a large amount of human data, 
including epidemiology studies.
    iii. Animal data considered in evaluating the proposed regulations 
are consistent with human data with respect to dose related skeletal 
effects.
    4.  Carcinogenicity.  Fluoride has been the subject of a 
comprehensive review by the National Research Council (National Academy 
of Sciences Subcommittee of Health Effects of Ingested Fluoride) who 
concluded that ``... the available laboratory data are insufficient to 
demonstrate a carcinogenic effect of fluoride in animals.'' and that 
``... the weight of evidence from more than 50 epidemiological studies 
does not support the hypothesis of an association between fluoride 
exposure and increased cancer risk in humans.'' EPA is in agreement 
with the conclusions reached by the National Academy of Science (NAS).
    The available information does not support the regulation of 
cryolite as a carcinogen and it has been classified as a Group D 
chemical (not classifiable as to human carcinogenicity).

C. Exposures and Risks

    1. From food and feed uses.  Tolerances have been established (40 
CFR 180.145) for the residues of cryolite In or on a variety of raw 
agricultural commodities. Risk assessments were conducted by EPA to 
assess dietary exposures and risks from cryolite as follows:
    i. Acute exposure and risk. Based on the available acute toxicity 
data, EPA has determined that cryolite does not pose any acute dietary 
risk.
    ii. Chronic exposure and risk. The weight-of-the-evidence dietary 
risk assessment was conducted utilizing the following factors. All 
calculations are based on 2 L/day water consumption and 70 kg adult.
    a. There exists no directly applicable scientific documentation of 
adverse medical effects at levels of fluoride below 8 mg/L 0.23 mg/kg/
day. (U.S. EPA. 1985. National Primary Drinking Water Regulations; 
Fluoride. Proposed Rulemaking. May 14, 1985, 50 FR 20166).
    b. Less than 0.4% of the U.S. population (on public water supplies) 
is exposed to greater than 2 mg/L fluoride 0.057 mg/kg/day in the 
public water supply. (U.S. EPA. 1985. drinking Water Criteria Document 
on fluoride. U.S. EPA Office of Drinking Water, Washington, DC TR-832-
5. pg. IV-3, Table IV-1.)
    The dietary exposure estimates used reassessed tolerances and 
percent of crop treated. These exposure estimates are conservative 
since average residues were not calculated and monitoring data were not 
used to refine residue estimates.
    Section 408(b)(2)(F) allows the Agency to use data n the actual 
percent of crop treated when establishing a tolerance only where the 
Agency can make the following findings:
    (a) That data used are reliable and provided a valid basis for 
showing the percentage of food derived from a crop that is likely 
contain residues.
    (b) That the exposure estimate does not underestimate the exposure 
for any significant subpopulation.
    (c) Where data on regional pesticide use and food consumption are 
available, that the exposure estimate does not understate exposure for 
any regional population. In addition, the Agency must provide for 
periodic evaluation of any estimates used.
    Percent of crop treated estimates are derived from federal and 
market survey data. EPA considers these data reliable. Typically a 
range of estimates are supplied and the upper end of this range is used 
for the exposure assessment. By using this upper end estimate of 
percent crop treated, EPA is reasonably certain that exposure is not 
underestimated for any significant subpopulation. 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. Review of this regional data allows 
EPA to be reasonably certain that no regional population is exposed to 
residue levels higher than those estimated by EPA. EPA has made these 
findings when appropriate with respect to the proposed tolerance. EPA 
has not provided for periodic reevaluation of the data on percent crop 
treated because this tolerance has a time-limitation.
    2. From drinking water-- i. Acute exposure and risk. Based on the 
available acute toxicity data, EPA has determined that fluoride does 
not pose any acute dietary risk.
    ii. Chronic exposure and risk. Fluoride levels in public drinking 
water are regulated under the Safe Drinking Water Act. EPA has 
established a Maximum Concentration Limit (MCL) at 4.0 mg/L 0.114 mg/
kg/day to protect against crippling skeletal fluorosis (April 2, 1986) 
(51 FR 11396). The MCL established on April 2, 1986 finalizes interim 
regulations set in the Federal Register of November 14, 1985 (50 FR 
47142), and proposed in the Federal Register of May 14, 1985 (50 FR 
20164). In addition, these Federal Register notices established a 
Secondary Maximum Contaminant Level (SMCL) at 2.0 mg/L 0.057 mg/kg/day 
for cosmetic effects (objectionable dental fluorosis) which are not 
considered to be adverse health effects by the Surgeon General.
    As described above, less than 0.4% of the U.S. population (on 
public water supplies) is exposed to greater than 2 mg/L fluoride 0.057 
mg/kg/day in the public water supply.
    3. From non-dietary exposure.  Cryolite is registered for use on 
ornamentals, a use which could result in residential, non-occupational 
exposure. It is not registered for indoor use. EPA has not estimated 
non-dietary or residential exposure from registered ornamental uses of 
cryolite because
    i. There are no toxicological endpoints identified for cryolite.
    ii. Fluoride occurs naturally in the environmental background and 
there would not be significant exposure to fluoride from the use of 
cryolite.
    iii. It would not be appropriate since the available information 
regarding solubility and degradation indicates that there would likely 
be no appreciable dermal absorption. The Agency does not anticipate 
significant non-dietary exposure from the use of cryolite.
    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

[[Page 64298]]

toxicity and conducting cumulative risk assessments. For most 
pesticides, although the Agency has some information in its files that 
may turn out to be helpful in eventually determining whether a 
pesticide shares a common mechanism of toxicity with any other 
substances, EPA does not at this time have the methodologies to resolve 
the complex scientific issues concerning common mechanism of toxicity 
in a meaningful way. EPA has begun a pilot process to study this issue 
further through the examination of particular classes of pesticides. 
The Agency hopes that the results of this pilot process will increase 
the Agency's scientific understanding of this question such that EPA 
will be able to develop and apply scientific principles for better 
determining which chemicals have a common mechanism of toxicity and 
evaluating the cumulative effects of such chemicals. The Agency 
anticipates, however, that even as its understanding of the science of 
common mechanisms increases, decisions on specific classes of chemicals 
will be heavily dependent on chemical specific data, much of which may 
not be presently available.
    Although at present the Agency does not know how to apply the 
information in its files concerning common mechanism issues to most 
risk assessments, there are pesticides as to which the common mechanism 
issues can be resolved. These pesticides include pesticides that are 
toxicologically dissimilar to existing chemical substances (in which 
case the Agency can conclude that it is unlikely that a pesticide 
shares a common mechanism of activity with other substances) and 
pesticides that produce a common toxic metabolite (in which case common 
mechanism of activity will be assumed).
    EPA does not have, at this time, available data to determine 
whether cryolite has a common mechanism of toxicity with other 
substances or how to include this pesticide in a cumulative risk 
assessment. Unlike other pesticides for which EPA has followed a 
cumulative risk approach based on a common mechanism of toxicity, 
cryolite does not appear to produce a toxic metabolite produced by 
other substances. For the purposes of this tolerance action, therefore, 
EPA has not assumed that cryolite has a common mechanism of toxicity 
with other substances. For the purpose of this time-limited tolerance, 
the Agency has considered risks from cryolite and from fluoride in 
intentionally fluoridated water.

D. Aggregate Risks and Determination of Safety for U.S. Population

    1. Acute risk.  Based on the available acute toxicity data, EPA has 
determined that cryolite does not pose any acute dietary risk.
    2. Chronic risk.  Fluoride is ubiquitous and may be present at low 
levels in air, soils and in foodstuffs that have not been treated with 
cryolite and/or synthetic cryolite as well as in drinking water. The 
atmospheric levels of fluoride and incidental dietary exposures to 
fluoride as a toothpaste additive or as a dental treatment contribute 
relatively little to the average level of dietary fluoride exposure and 
are not further considered in the exposure estimate.
    Dietary exposure estimates using reassessed tolerance/including the 
subject tolerance for potatoes ( which is estimated as approximately 
0.00016 mg/kg/day) and percent of crops treated are approximately 0.020 
mg/kg/day for the U.S. population and 0.028 mg/kg/day for the highest 
exposed subgroup (females 13 years old and over, nursing). These 
exposure estimates are conservative since average residues were not 
calculated and monitoring data were not used to refine residue 
estimates.
    Therefore, it can be concluded that levels of fluoride in/on food 
from the agricultural use of Cryolite plus fluoride levels in U.S. 
drinking water supplies (0.057 mg/kg/day) results in a high-end daily 
dietary intake of fluoride of approximately 0.085 mg/kg/day. This is 
less than the Maximum Concentration Limit (MCL) of 4.0 mg/L 0.114 mg/
kg/day, a level which provides no known or anticipated adverse health 
effect as determined by the Surgeon General.
    Due to the fact that fluoride naturally occurs at low levels in 
food and air as well as drinking water, there is a low percentage of 
the population (0.4%) exposed to levels above the secondary Maximum 
Contaminant Level (2 mg/L) and below the MCL, dietary exposure from 
agricultural uses is low (typically much less than ca. 66% of the 
levels found in intentionally fluoridated water), and aggregate high-
end exposure is estimated to be below the MCL, EPA concludes there is a 
reasonable certainty that no harm will result from aggregate exposure 
to fluoride residues.
    3. Short-and intermediate -term risk.  Short-and intermediate-term 
risk aggregate exposure takes into account chronic dietary food and 
water (considered to be a background exposure level) plus indoor and 
outdoor residential exposure. As explained above, EPA does not 
anticipate significant non-dietary (residential) exposure from the use 
of cryolite.

E. Aggregate Cancer Risk for U.S. Population

    As described above, the available information does not support the 
regulation of cryolite as a carcinogen and it has been classified as a 
Group D chemical (not classifiable as to human carcinogenicity).

F. 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 cryolite, EPA considered data from oral 
developmental toxicity studies in the rat and mouse; and a range-
finding study in the rabbit as well as data from a 2-generation 
reproduction study in the rat. The developmental toxicity studies are 
designed to evaluate adverse effects on the developing organism 
resulting from pesticide exposure during prenatal development to one or 
both parents. Reproduction studies provide information relating to 
effects from exposure to the pesticide on the reproductive capability 
of mating animals and data on systemic toxicity.
    FFDCA section 408 provides that EPA shall apply an additional 
tenfold margin of safety for infants and children in the case of 
threshold effects to account for pre-and post-natal toxicity and the 
completeness of the database unless EPA determines that a different 
margin of safety will be safe for infants and children. Margins of 
safety are incorporated into EPA risk assessments either directly 
through use of a margin of exposure 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 MOE and uncertainty factor (usually 100 for combined 
inter- and intra-species variability) and not the additional tenfold 
MOE/uncertainty 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 MOE/safety factor.
    ii. Developmental toxicity studies.  A developmental toxicity study 
conducted with cryolite in rats at dose levels of 0, 750, 1,500, and 
3,000 mg/kg/day (gavage) in which the NOEL for both developmental and 
maternal toxicity was 3,000 mg/kg/day. At this dose level, the only 
observation was whitening of the teeth of dams.

[[Page 64299]]

    A developmental toxicity study conducted in female mice with 
Cryolite at dose levels of 0, 30, 100 and 300 mg/kg/day (gavage) in 
which the NOEL for maternal toxicity was 30 mg/kg/day and the LOEL was 
100 mg/kg/day based on the occurrence of dark red contents of the 
stomach. Fetuses at the highest dose tested, 300 mg/kg/day exhibited 
bent ribs and bent limb bones.
    A range-finding developmental toxicity study conducted in female 
rabbits with Cryolite at dose levels of 0, 10, 30, 100, 300 and 1,000 
mg/kg/day (gavage) which showed only severe maternal effects at all 
doses. There were no developmental findings in the fetuses up to 30 mg/
kg/day. At doses greater than 30 mg/kg/day, developmental findings were 
not observed due to the severe maternal toxicity.
    A new rabbit developmental study is not required at this time since 
there are two acceptable rodent developmental studies (rat and mouse) 
showing no specific adverse developmental effects. In addition, the 
National Academy of Sciences (NAS) report supports this decision. It is 
unlikely that an additional rabbit developmental study would alter the 
risk evaluation for cryolite.
    The rabbit range-finding study suggested that severe maternal 
toxicity occurred at lower doses than external developmental toxicity. 
However, following an extensive literature evaluation, the National 
Research Council (National Academy of Sciences Subcommittee of Health 
Effects of Ingested Fluoride) (NAS) determined that:
    There have been reports of adverse effects on reproductive 
outcomes associated with high levels of fluoride intake in many 
animal species. In most of the studies, however, the fluoride 
concentrations associated with adverse effects were far higher than 
those encountered in drinking water. ...
    Based on these findings, the subcommittee concludes that the 
fluoride concentrations associated with adverse reproductive effects 
in animals are far higher than those to which human populations are 
exposed. Consequently, ingestion of fluoride at current 
concentrations should have no adverse effects on human reproduction.

    iii. Reproductive toxicity study.  A 2-generation reproduction 
study conducted with Cryolite in the diet of rats at dose levels of 0, 
200, 600, and 1,800 ppm (representing 0, 14, 42, and 128 mg/kg/day for 
males and 0, 16, 49, and 149 mg/kg/day for females, respectively, 
during premating) in which the LOEL for systemic toxicity was 200 ppm 
(15 mg/kg/day) based on dental fluorosis. The NOEL for decreased pup 
body weight was 46 mg/kg/day and, at the lowest dose tested (8 mg/kg/
day) there was parental toxicity. Therefore, there was pup toxicity 
only in the presence of parental toxicity.
    iv. Pre- and post-natal sensitivity.  Based on current data 
requirements, the database relative to pre- and post-natal toxicity is 
complete. These data taken together suggest minimal concern for 
developmental or reproductive toxicity and do not indicate any 
increased pre- or post-natal sensitivity.
    v. Conclusion.  Therefore, EPA concludes that reliable data support 
use of the weight-of-the-evidence risk assessment approach for the 
assessment of risks to infants and children associated with the use of 
cryolite and that an additional safety factor is not needed.
    2. Acute risk.  As described above, based on available acute 
toxicity data, EPA has determined that cryolite does not pose any acute 
dietary risk.
    3. Chronic risk.  The high end dietary exposure estimate for 
infants and children using reassessed tolerances and percent of crops 
treated is 0.024 mg/kg/day. This is lower than the exposure estimate of 
0.028 mg/kg/day which was used in the Agency's determination of safety 
for the U.S. population described above.
    EPA concludes that there is a reasonable certainty that no harm 
will result to infants and children from aggregate exposure to fluoride 
residues.
    4. Short- or intermediate- term risk.  As described above, EPA has 
determined that cryolite does not exhibit any adverse health effects 
occurring as a result of short- or intermediate-term dietary and non-
dietary exposure.

III. Other Considerations

A. Metabolism In Plants and Animals

    The metabolism of the subject insecticides in plants and animals is 
adequately understood.
    Open literature studies show that human and animal metabolism of 
cryolite and/or synthetic cryolite manifests itself as normal free 
fluoride metabolism. That is, dissociation occurs, producing free 
fluoride ions which are assimilated into bone. The residue of concern 
in animals is total fluoride.
    Plant residues are inorganic surface residues of cryolite which are 
measured as total fluoride. Uptake and translocation of cryolite 
residues from soil is unlikely due to the low water solubility of 
cryolite.

B. Analytical Enforcement Methodology

    An adequate analytical method (fluoride specific electrode) is 
available for enforcement purposes for plant and animal residues. The 
limit of quantitation is 0.05 ppm. Because cryolite is an inorganic 
ionic compound, the requirement for data using the multi-residue 
protocols in the Pesticide Analytical Manual (PAM) Vol. I is not 
applicable.
    Because of the long lead time from establishing these tolerances, 
to publication of the enforcement methodology in the PAM Vol. II, the 
analytical methodology is being made available in the interim to anyone 
interested in pesticide enforcement when requested from; Calvin Furlow, 
Public Information Branch, Field Operations Division (H7506C), Office 
of Pesticide Programs, Environmental Protection Agency, 401 M St., 
SW.,Washington, DC 20460. Office location and telephone number; Rm. 
1128, CM #2, 1921 Jefferson Davis Hwy., VA 22202, (703)-305-5232.

C. Magnitude of Residues

    It has been determined that residues of cryolite are not expected 
to exceed 2.0 ppm in potatoes and 22.0 ppm in processed potato waste.
    Data submitted in support of the subject petition show background 
levels of fluoride in untreated potatoes ranged from 0.14 ppm to 0.31 
ppm and are consistent with the ranges reported in the open literature. 
Levels of fluoride found in the treated potatoes ranged from 0.18 ppm 
to 0.94 ppm. The residue analytical method used for enforcing the 
subject tolerance and regulation cannot distinguish between the 
naturally occurring fluoride and the fluoride resulting from use of 
cryolite and/or synthetic cryolite.
    A potato processing study showed that cryolite residues did not 
concentrate in potato chips, flakes or granules. Therefore, tolerances 
on these commodities are not required.
    There is no reasonable expectation of finite fluoride residues in 
ruminant or poultry tissues as a result of livestock ingestion of 
cryolite and this situation falls under 40 CFR 180.6 (a)(3). Therefore, 
tolerances for cryolite residues in meat, milk, poultry, and eggs are 
not required.

D. International Residue Limits

    No Codex Maximum Residue Limits (MRLs) for fluorine compounds 
(cryolite) exist. Therefore, there are no questions of compatibility 
with respect to Codex MRLs and U. S. tolerances.

E. Rotational Crop Restrictions

    The residue available to rotational crops is expected to be 
negligible with

[[Page 64300]]

respect to the amount of free fluorine occurring naturally in soil.

F. Endocrine Effects

    No evidence of such effects were reported in the toxicology studies 
described above. There is no evidence at this time that cryolite causes 
endocrine effects.

IV. Conclusion

    Therefore, the tolerance is established for residues of cryolite in 
or on potatoes at 2.0 ppm and in potato waste from processing at 22.0 
ppm.

V. 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 3, 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.

VI. Public Docket

    A record has been established for this rulemaking under docket 
control number [OPP-300586] (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.
    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.

VII. Regulatory Assessment Requirements

    This final rule establishes a tolerance under FFDCA section 408(d) 
in response to a petition submitted to the Agency. 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(d), 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 the 
Agency's generic certification for tolerance actions published on May 
4, 1981 (46 FR 24950) and was provided to the Chief Counsel for 
Advocacy of the Small Business Administration.

VIII. 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: November 21, 1997.
Linda A. Travers,
Acting Director, Office of Pesticide Programs.
    Therefore, 40 CFR chapter I is amended as follows:

[[Page 64301]]

PART 180--[AMENDED]

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

    Authority : 21 U.S.C. 346a and 371.

    b. In Sec. 180.145:
    i. By designating paragraph (a) as paragraph (a)(1), by adding 
paragraph (a)(2), and by adding a heading to paragraph (a).
    ii. By removing paragraph (c) and redesignating paragraph (b) as 
new paragraph (c) and adding a heading.
    iii. By adding and reserving new paragraphs (b) and (d) with 
headings.
    The amendments to Sec. 180.145 read as follows:


Sec. 180.145  Fluorine compounds: tolerances for residues.

    (a) General. *        *        *
    (2) Time-limited tolerances are established for residues of the 
insecticidal fluorine compounds cryolite and synthetic cryolite (sodium 
aluminum fluoride) in or on the commodities as follows:

                                                                                                                                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------
                         Commodity                                        Parts per million                          Expiration/revocation date         
--------------------------------------------------------------------------------------------------------------------------------------------------------
Potatoes..................................................                                            2.0                                     11/21/2001
Potatoes, waste from processing...........................                                           22.0                                     11/21/2001
--------------------------------------------------------------------------------------------------------------------------------------------------------

    (b) Section 18 emergency exemptions. [Reserved]
    (c) Tolerances with regional registrations. *        *        *
    (d) Indirect or inadvertent residues. [Reserved]

[FR Doc. 97-31920 Filed 12-4-97; 8:45 am]
BILLING CODE 6560-50F