[Federal Register Volume 62, Number 156 (Wednesday, August 13, 1997)]
[Rules and Regulations]
[Pages 43284-43291]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-21145]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[OPP-300525; FRL-5735-2]
RIN 2070-AB78


Propiconazole; Pesticide Tolerances for Emergency Exemptions

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This regulation establishes time-limited tolerances for 
combined residues of propiconazole and its metabolites determined as 
2,4-dichlorobenzoic acid (DCBA) in or on grain sorghum, grain; grain 
sorghum, stover; and sorghum aspirated grain fractions . This action is 
in response to EPA's granting of emergency exemptions under section 18 
of the Federal Insecticide, Fungicide, and Rodenticide Act authorizing 
use of the pesticide on grain sorghum. This regulation establishes 
maximum permissible levels for residues of propiconazole 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 tolerances will expire and are revoked on July 31, 1998.

DATES: This regulation is effective August 13, 1997. Objections and 
requests for hearings must be received by EPA on or before October 14, 
1997.

ADDRESSES: Written objections and hearing requests, identified by the 
docket control number, [OPP-300525], 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-300525], must also be submitted to: Public 
Information and Records Integrity Branch, Information Resources and 
Services Division (7506C), Office of

[[Page 43285]]

Pesticide Programs, Environmental Protection Agency, 401 M St., SW., 
Washington, DC 20460. In person, bring a copy of objections and hearing 
requests to Rm. 1132, CM #2, 1921 Jefferson Davis Hwy., Arlington, VA.
    A copy of objections and hearing requests filed with the Hearing 
Clerk may also be submitted electronically by sending electronic mail 
(e-mail) to: [email protected]. Copies of objections and 
hearing requests must be submitted as an ASCII file avoiding the use of 
special characters and any form of encryption. Copies of objections and 
hearing requests will also be accepted on disks in WordPerfect 5.1 file 
format or ASCII file format. All copies of objections and hearing 
requests in electronic form must be identified by the docket control 
number [OPP-300525]. 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: Stephen Schaible, 
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) 308-9362, 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 tolerances for 
combined residues of the fungicide propiconazole, 1-[[2-(2,4-
dichlorophenyl)-4-propyl-1,3-dioxolan-2-yl]methyl]-1H-1,2,4-triazole 
and its metabolites determined as 2,4-dichlorobenzoic acid (DCBA), in 
or on grain sorghum, grain at 0.2 parts per million (ppm); grain 
sorghum, stover at 1.5 ppm; and sorghum aspirated grain fractions at 20 
ppm . These tolerances will expire and are revoked on July 31, 1998. 
After July 31, 1998, EPA will publish a document in the Federal 
Register to remove the revoked tolerances from the Code of Federal 
Regulations.

I. Background and Statutory Authority

    The Food Quality Protection Act of 1996 (FQPA) (Pub. L. 104-170) 
was signed into law August 3, 1996. FQPA amends both the Federal Food, 
Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 301 et seq., and the Federal 
Insecticide, Fungicide, and Rodenticide Act (FIFRA), 7 U.S.C. 136 et 
seq. The FQPA amendments went into effect immediately. Among other 
things, FQPA amends FFDCA to bring all EPA pesticide tolerance-setting 
activities under a new section 408 with a new safety standard and new 
procedures. These activities are described below and discussed in 
greater detail in the final rule establishing the time-limited 
tolerance associated with the emergency exemption for use of 
propiconazole on sorghum (61 FR 58135, November 13, 1996)(FRL-5572-9).
    New section 408(b)(2)(A)(i) of the FFDCA allows EPA to establish a 
tolerance (the legal limit for a pesticide chemical residue in or on a 
food) only if EPA determines that the tolerance is ``safe.'' Section 
408(b)(2)(A)(ii) defines ``safe'' to mean that ``there is a reasonable 
certainty that no harm will result from aggregate exposure to the 
pesticide chemical residue, including all anticipated dietary exposures 
and all other exposures for which there is reliable information.'' This 
includes exposure through drinking water and in residential settings, 
but does not include occupational exposure. Section 408(b)(2)(C) 
requires EPA to give special consideration to exposure of infants and 
children to the pesticide chemical residue in establishing a tolerance 
and to ``ensure that there is a reasonable certainty that no harm will 
result to infants and children from aggregate exposure to the pesticide 
chemical residue***.''
    Section 18 of FIFRA authorizes EPA to exempt any Federal or State 
agency from any provision of FIFRA, if EPA determines that ``emergency 
conditions exist which require such exemption.'' This provision was not 
amended by FQPA. EPA has established regulations governing such 
emergency exemptions in 40 CFR part 166.
    Section 408(l)(6) of the FFDCA requires EPA to establish a time-
limited tolerance or exemption from the requirement for a tolerance for 
pesticide chemical residues in food that will result from the use of a 
pesticide under an emergency exemption granted by EPA under section 18 
of FIFRA. Such tolerances can be established without providing notice 
or period for public comment.
    Because decisions on section 18-related tolerances must proceed 
before EPA reaches closure on several policy issues relating to 
interpretation and implementation of the FQPA, EPA does not intend for 
its actions on such tolerance to set binding precedents for the 
application of section 408 and the new safety standard to other 
tolerances and exemptions.

II. Emergency Exemption for Propiconazole on Grain Sorghum and 
FFDCA Tolerances

    Sorghum ergot (Claviceps africana) is a new disease to grain 
sorghum in the United States. It was detected on sorghum in the Rio 
Grande Valley of Texas in February and March of 1997. The fungus 
infects unfertilized flower ovaries, with the resulting fungal growth 
eventually producing a sticky fluid known as honeydew. In sorghum grown 
for hybrid seed production, the disease reduces seed yield by 
decreasing the availability of viable pollen. In sorghum grown for 
grain, the disease lowers grain yield and quality, makes threshing 
difficult, and reduces seed germination. Currently there are no 
products registered for sorghum which are effective in controlling 
ergot, nor are there feasible alternative control practices. Efficacy 
data from Brazil show that the triazole group of fungicides was most 
successful at controlling the disease; based on limited data submitted 
by the registrant, propiconazole appears effective against sorghum 
ergot. EPA has authorized under FIFRA section 18 the use of 
propiconazole on grain sorghum for control of sorghum ergot in 
Illinois, Kansas, Nebraska, New Mexico, Oklahoma, and Texas. After 
having reviewed these submissions, EPA concurs that emergency 
conditions exist for these states.
    As part of its assessment of these emergency exemptions, EPA 
assessed the potential risks presented by residues of propiconazole in 
or on grain sorghum commodities. In doing so, EPA considered the new 
safety standard in FFDCA section 408(b)(2), and EPA decided that the 
necessary tolerances under FFDCA section 408(l)(6) would be consistent 
with the new safety standard and with FIFRA section 18. Consistent with 
the need to move quickly on the emergency exemptions in order to 
address an urgent non-routine situation and to ensure that the 
resulting food is safe and lawful, EPA is issuing these tolerances 
without notice and opportunity for public comment under section 408(e), 
as provided in section 408(l)(6). Although these tolerance will expire 
and are revoked on July 31, 1998, under FFDCA section 408(l)(5), 
residues of the pesticide not in excess of the amounts specified in the 
tolerances remaining in or on grain sorghum, grain; grain sorghum, 
stover; and sorghum aspirated grain fractions after that date will not 
be unlawful, provided the pesticide is applied in a manner that was 
lawful under FIFRA. EPA will take action to revoke these tolerances 
earlier

[[Page 43286]]

if any experience with, scientific data on, or other relevant 
information on this pesticide indicate that the residues are not safe.
    Because these tolerances are being approved under emergency 
conditions EPA has not made any decisions about whether propiconazole 
meets EPA's registration requirements for use on grain sorghum or 
whether permanent tolerances for this use would be appropriate. Under 
these circumstances, EPA does not believe that these tolerances serve 
as a basis for registration of propiconazole by a State for special 
local needs under FIFRA section 24(c). Nor do these tolerances serve as 
the basis for any State other than Illinois, Kansas, Nebraska, New 
Mexico, Oklahoma, and Texas 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 exemptions for propiconazole, 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 percent 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 hundredfold MOE is based on the same rationale as 
the hundredfold 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 
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 groundwater 
or surface water that is

[[Page 43287]]

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 (non-nursing 
infants less than 1 year old) was not regionally based.

IV. Aggregate Risk Assessment and Determination of Safety

    Consistent with section 408(b)(2)(D), EPA has reviewed the 
available scientific data and other relevant information in support of 
this action, EPA has sufficient data to assess the hazards of 
propiconazole and to make a determination on aggregate exposure, 
consistent with section 408(b)(2), for time-limited tolerances for 
combined residues of propiconazole, 1-[[2-(2,4-dichlorophenyl)-4-
propyl-1,3-dioxolan-2-yl]methyl]-1H-1,2,4-triazole and its metabolites 
determined as 2,4-dichlorobenzoic acid (DCBA) on grain sorghum, grain 
at 0.2 ppm; grain sorghum, stover at 1.5 ppm; and sorghum aspirated 
grain fractions at 20 ppm. EPA's assessment of the dietary exposures 
and risks associated with establishing the tolerances follows.

A. Toxicological Profile

    EPA has evaluated the available toxicity data and considered its 
validity, completeness, and reliability as well as the relationship of 
the results of the studies to human risk. EPA has also considered 
available information concerning the variability of the sensitivities 
of major identifiable subgroups of consumers, including infants and 
children. The nature of the toxic effects caused by propiconazole are 
discussed below.
    1. Acute toxicity. For acute dietary risk assessment, EPA 
recommends use of the developmental NOEL of 30 mg/kg/day from a 
developmental toxicity study in rats. The LEL of 90 mg/kg/day was based 
on the increased incidence of unossified sternebrae, rudimentary ribs, 
and shortened or absent renal papillae. This risk assessment will 
evaluate acute dietary risk to the population of concern, females 13 
years and older.
     2. Short - and intermediate - term toxicity. For short- and 
intermediate-term dermal MOE calculations, EPA recommends use of the 
developmental NOEL of 30 mg/kg/day from the developmental toxicity 
study in rats. For short- and intermediate-term inhalation MOE 
calculations, EPA recommends use of the NOEL of 92.8 mg/kg/day, the 
highest dose tested (HDT) from the 5-day inhalation toxicity study in 
rats.
    3. Chronic toxicity. EPA has established the RfD for propiconazole 
at 0.013 milligrams/kilogram/day (mg/kg/day). This RfD is based on a 
NOEL of 1.25 mg/kg/day taken from a 1-year feeding study in dogs. The 
effect seen at the LEL of 6.25 mg/kg/day is mild irritation of the 
gastric mucosa. An uncertainty factor of 100 was added to take into 
account interspecies and intraspecies variation.
    4. Carcinogenicity. Propiconazole has been classified as a Group C, 
``possible human carcinogen,'' chemical by the Agency. EPA recommends 
using the RfD approach for quantitation of human risk. Therefore, the 
RfD is deemed protective of all chronic human health effects, including 
cancer.

B. Exposures and Risks

    1. From food and feed uses. Tolerances have been established (40 
CFR 180.434) for the combined residues of propiconazole, 1-[[2-(2,4-
dichlorophenyl)-4-propyl-1,3-dioxolan-2-yl]methyl]-1H-1,2,4-triazole 
and its metabolites determined as 2,4-dichlorobenzoic acid (DCBA), in 
or on a variety of raw agricultural commodities. Secondary residues in 
animal commodities are not expected to exceed existing tolerances as a 
result of the proposed use. Risk assessments were conducted by EPA to 
assess dietary exposures and risks from propiconazole as follows:
    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 assumed tolerance level residues and 100% crop treated. The 
resulting high-end exposure estimate of 0.01 mg/kg/day, which results 
in a dietary (food only) MOE of 3,000 for females 13+ years old, should 
be viewed as conservative; refinement using anticipated residue values 
and percent crop-treated data in conjunction with Monte Carlo analysis 
would result in a lower acute dietary exposure estimate.
    ii. Chronic exposure and risk. For the purpose of assessing chronic 
dietary exposure from propiconazole, EPA assumed anticipated residues 
and percent of crop treated refinements for many of the existing uses 
to estimate the Anticipated Residue Contribution (ARC) from existing 
and proposed uses. While more refined than TMRC exposure estimates, the 
assumptions of tolerance level residues and 100% of crop treated for 
the proposed use and numerous existing uses still result in 
overestimation of exposure. Based on the above assumptions, chronic 
dietary exposure to the U.S. population represents 7% of the RfD. 
Dietary exposure to the subgroup most highly exposed, non-nursing 
infants less than 1 year, utilizes 20% of the RfD.
    2. From drinking water. Review of terrestrial field dissipation 
data indicates that propiconazole is persistent and leaches into 
groundwater. There is no established Maximum Contaminant Level (MCL) 
for residues of propiconazole in drinking water. No drinking water 
health advisory levels have been established for propiconazole.
    Because the Agency lacks sufficient water-related exposure data to 
complete a comprehensive drinking water risk

[[Page 43288]]

assessment for many pesticides, EPA has commenced and nearly completed 
a process to identify a reasonable yet conservative bounding figure for 
the potential contribution of water-related exposure to the aggregate 
risk posed by a pesticide. In developing the bounding figure, EPA 
estimated residue levels in water for a number of specific pesticides 
using various data sources. The Agency then applied the estimated 
residue levels, in conjunction with appropriate toxicological endpoints 
(RfD's or acute dietary NOEL's) and assumptions about body weight and 
consumption, to calculate, for each pesticide, the increment of 
aggregate risk contributed by consumption of contaminated water. While 
EPA has not yet pinpointed the appropriate bounding figure for exposure 
from contaminated water, the ranges the Agency is continuing to examine 
are all below the level that would cause propiconazole to exceed the 
RfD if the tolerance being considered in this document were granted. 
The Agency has therefore concluded that the potential exposures 
associated with propiconazole in water, even at the higher levels the 
Agency is considering as a conservative upper bound, would not prevent 
the Agency from determining that there is a reasonable certainty of no 
harm if the tolerance is granted.
    3. From non-dietary exposure. Propiconazole is currently registered 
for use on the following residential non-food sites: a preservative 
treatment for finished wood (window moldings, fences, etc.), and for 
ornamental turf and lawns. While EPA does not consider that these types 
of outdoor residential uses constitute a chronic residential exposure 
scenario, EPA acknowledges that there may be short- and intermediate-
term, non-occupational exposure scenarios. Toxicological endpoints have 
been identified for short- and intermediate-term risk assessment. 
However, no acceptable, reliable data to assess these potential risks 
are available at this time. Given the time-limited nature of this 
request, the need to make emergency exemption decisions quickly, and 
the significant scientific uncertainty at this time about how to 
aggregate non-occupational exposure with dietary exposure, the Agency 
will make the safety determination for these tolerances based on those 
factors which it can reasonably integrate into a risk assessment. What 
limited data are available to the Agency suggest that residential use 
of propiconazole by homeowners is quite limited.
    4. Cumulative exposure to substances with common mechanism of 
toxicity. Propiconazole is a member of the triazole class of 
pesticides. Other triazoles include bitertanol, cyproconazole, 
diclobutrazole, difenoconazole, diniconazole, fenbuconazole, 
flusilazole, hexaconazole, myclobutanil, penconazole, tebuconazole, 
tetraconazole, triadimefon, and triadimenol. 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 commonmechanism 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 propiconazole 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, 
propiconazole 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 propiconazole has a common mechanism of 
toxicity with other substances.

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

    1. Acute risk. For the population subgroup of concern, females 13+ 
years and older, the calculated MOE is 3,000. The Agency acknowledges 
the potential for exposure to propiconazole in drinking water, but does 
not expect that exposure would result in an aggregate MOE (food plus 
water) that would exceed the Agency's level of concern for acute 
dietary exposure.
    2. Chronic risk. Using the ARC exposure assumptions described 
above, EPA has concluded that aggregate exposure to propiconazole from 
food will utilize 7% of the RfD for the U.S. population. The major 
identifiable subgroup with the highest aggregate exposure is non-
nursing infants less than 1 year (discussed below). 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. 
Despite the potential for exposure to propiconazole in drinking water 
and from non-dietary, non-occupational exposure, EPA does not expect 
the aggregate exposure to exceed 100% of the RfD. EPA concludes that 
there is a reasonable certainty that no harm will result from aggregate 
exposure to propiconazole residues.
    3. Short- and intermediate-term risk. Short- and intermediate-term 
aggregate risk estimates take into account exposure from chronic 
dietary food and water (considered to be a background exposure level) 
plus potential indoor and outdoor residential exposures. Based on the 
large acute dietary MOE for the subgroup of concern (3,000 for females 
13+), the small percentage of the RfD occupied for the U.S. population 
(7%), and the minimal non-dietary exposure, in our best scientific

[[Page 43289]]

judgment, the short- and intermediate-term aggregate risk from exposure 
to propiconazole will not exceed the Agency's level of concern.

D. Aggregate Cancer Risk for U.S. Population

     Propiconazole has been classified as a Group C, ``possible human 
carcinogen,'' chemical by the Agency. EPA recommends using the RfD 
approach for quantification of human risk. Human health risk concerns 
due to long-term exposure to propiconazole residues are adequately 
addressed by the aggregate chronic exposure analysis using the RfD.

E. Aggregate Risks and Determination of Safety for Infants and Children

    1. Safety factor for infants and children-- a. In general. In 
assessing the potential for additional sensitivity of infants and 
children to residues of propiconazole, EPA considered data from 
developmental toxicity studies in the rat and rabbit and a two-
generation reproduction study in the rat. The developmental toxicity 
studies are designed to evaluate adverse effects on the developing 
organism resulting from maternal pesticide exposure during gestation. 
Reproduction studies provide information relating to effects from 
exposure to the pesticide on the reproductive capability of mating 
animals and data on systemic toxicity.
    FFDCA section 408 provides that EPA shall apply an additional 
tenfold margin of safety for infants and children in the case of 
threshold effects to account for pre-and post-natal toxicity and the 
completeness of the database unless EPA determines that a different 
margin of safety will be safe for infants and children. Margins of 
safety are incorporated into EPA risk assessments either directly 
through use of a MOE analysis or through using uncertainty (safety) 
factors in calculating a dose level that poses no appreciable risk to 
humans. EPA believes that reliable data support using the standard 
hundredfold safety factor (usually 100 for combined inter- and intra-
species variability)) and not the additional tenfold safety factor when 
EPA has a complete data base under existing guidelines and when the 
severity of the effect in infants or children or the potency or unusual 
toxic properties of a compound do not raise concerns regarding the 
adequacy of the standard MOE/safety factor.
    b. Developmental toxicity studies. In the developmental toxicity 
study in rats, the maternal (systemic) NOEL was 30 mg/kg/day. The 
maternal LEL of 90 mg/kg/day was based on reduced body weight gain and 
rales in females. The developmental NOEL was also 30 mg/kg/day. The 
developmental LEL of 90 mg/kg/day was based on the increased incidence 
of unossified sternebrae, rudimentary ribs, and shortened or absent 
renal papillae. In the rabbit developmental toxicity study, the 
maternal (systemic) NOEL was 100 mg/kg/day. The maternal LEL of 250 mg/
kg/day was based on decreased food consumption and body weight gain. 
There was also an increased incidence of abortion at 400 mg/kg/day. The 
developmental NOEL was 400 mg/kg/day (HDT), based upon the lack of 
developmental delays or alterations.
    c. Reproductive toxicity study. From the 2-generation reproductive 
toxicity study in rats, the parental (systemic) LEL of 5 mg/kg/day 
(lowest dose tested) was based on the increased incidence of hepatic 
``clear-cell change'' at all dose levels; additionally, at 25 and 125 
mg/kg/day, decreased body weights, decreased food consumption, and/or 
an increased incidence of hepatic cellular swelling were observed. A 
NOEL for parental toxicity was not determined. The reproductive/ 
developmental NOEL was 25 mg/kg/day. The reproductive LEL of 125 mg/kg/
day was based on decreased offspring survival of second generation (F2) 
pups, and on decreased body weight throughout lactation, and an 
increase in the incidence of hepatic cellular swelling for both 
generations of offspring (F1 and F2 pups).
    d. Pre- and post-natal sensitivity. The pre- and post-natal 
toxicology data base for propiconazole is complete with respect to 
current toxicological 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 study. Based on the developmental and 
reproductive toxicity studies discussed above, for propiconazole there 
does not appear to be an extra sensitivity for pre- or post-natal 
effects.
    EPA notes developmental toxicity NOELs of 30 mg/kg/day in rats and 
400 mg/kg/day (HDT) in rabbits. Developmental toxicity was observed in 
rats at 90 mg/kg/day; these effects occurred in the presence of 
maternal toxicity. The significant developmental effects in the rat 
study required an acute dietary risk assessment for females 13+ years 
of age. The calculated MOE of 3,000 demonstrated that the developmental 
risks were below HED's level of concern. In rabbits, no developmental 
delays or alterations were noted; however, increased abortions were 
observed at the maternally toxic dose of 400 mg/kg/day. The 
developmental NOELs are more than 24- and 320-fold higher in rats and 
rabbits, respectively, than the NOEL of 1.25 mg/kg/day from the 1-year 
feeding study in dogs, which is the basis of the RfD.
    e. Conclusion. EPA concludes that reliable data support use of the 
standard hundredfold uncertainty factor and that an additional 
uncertainty factor is not needed to protect the safety of infants and 
children.
    2. Acute risk. The calculated acute dietary (food only) MOE for 
females 13+ years old (accounts for both maternal and fetal exposure) 
is 3,000. This MOE calculation was based on the developmental NOEL in 
rats of 30 mg/kg/day. This risk assessment assumed 100% crop treated 
and tolerance level residues on all treated crops consumed, resulting 
in a significant over-estimate of dietary exposure. The Agency does not 
expect any significant exposure from the residential use of 
propiconazole. Despite the potential for exposure to propiconazole in 
drinking water, EPA does not expect the acute aggregate exposure to 
exceed our level of concern. The large acute dietary MOE calculated for 
females 13+ years old provides assurance that there is a reasonable 
certainty of no harm for both females 13+ years and the pre-natal 
development of infants.
    3. Chronic risk. Using the conservative exposure assumptions 
described above, EPA has concluded that aggregate exposure to 
propiconazole from food will utilize 20% of the RfD for non-nursing 
infants less than 1 year old and 13% of the RfD for children 1 through 
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. Despite the potential for exposure to 
propiconazole in drinking water and from non-dietary, non-occupational 
exposure, EPA does not expect the aggregate exposure to exceed 100% of 
the RfD. EPA concludes that there is a reasonable certainty that no 
harm will result to infants and children from aggregate exposure to 
propiconazole residues.

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 propiconazole (1-[[2-(2,4-
dichlorophenyl)-4-propyl-1,3-dioxolan-2-yl]methyl]-1H-1,2,4-triazole), 
and its metabolites determined as 2,4-

[[Page 43290]]

 dichlorobenzoic acid (DCBA) and expressed as parent compound as 
specified in 40 CFR 180.434 .

B. Analytical Enforcement Methodology

    Adequate enforcement methodology is available to enforce the 
tolerance expression. Analytical methodologies for the determination of 
propiconazole and its metabolites in plant and animal commodities 
(Ciba-Geigy Analytical Methods AG-454 and AG-517, respectively) have 
been successfully validated by the Agency's Analytical Chemistry 
Laboratory and have been approved for publication in PAM II for 
enforcement purposes. These methods have not as of this time appeared 
in PAM II, but a copy of the methods may be obtained from the 
Information Resources and Services Division of OPP, at the address 
provided above.

C. Magnitude of Residues

    Residues of propiconazole are not expected to exceed 0.2 ppm in 
grain sorghum, grain or 1.5 ppm in grain sorghum, stover as a result of 
the proposed section 18 use. Residues are not expected to exceed 20 ppm 
on sorghum aspirated grain fractions based on the expected tolerance 
level for grain sorghum grain, 0.2 ppm, and the maximum concentration 
factor, of 100x, for sorghum aspirated grain fractions.

D. International Residue Limits

    There are no CODEX, Canadian, or Mexican maximum residue limits for 
propiconazole on sorghum; therefore, international harmonization is not 
an issue for this action.

E. Rotational Crop Restrictions

    Do not rotate to any crop intended for food, grazing, or any 
component of animal feed or bedding within 105 days of product 
application, unless the crop appears on the product label.

VI. Conclusion

    Therefore, tolerances are established for combined residues of 
propiconazole, 1-[[2-(2,4-dichlorophenyl)-4-propyl-1,3-dioxolan-2-
yl]methyl]-1H-1,2,4-triazole, and its metabolites determined as 2,4-
dichlorobenzoic acid (DCBA) in grain sorghum, grain at 0.2 ppm; grain 
sorghum, stover at 1.5 ppm; and sorghum aspirated grain fractions at 20 
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 October 14, 1997, file written objections to any 
aspect of this regulation and may also request a hearing on those 
objections. Objections and hearing requests must be filed with the 
Hearing Clerk, at the address given above (40 CFR 178.20). A copy of 
the objections and/or hearing requests filed with the Hearing Clerk 
should be submitted to the OPP docket for this rulemaking. The 
objections submitted must specify the provisions of the regulation 
deemed objectionable and the grounds for the objections (40 CFR 
178.25). Each objection must be accompanied by the fee prescribed by 40 
CFR 180.33(i). If a hearing is requested, the objections must include a 
statement of the factual issues on which a hearing is requested, the 
requestor's contentions on such issues, and a summary of any evidence 
relied upon by the requestor (40 CFR 178.27). A request for a hearing 
will be granted if the Administrator determines that the material 
submitted shows the following: There is genuine and substantial issue 
of fact; there is a reasonable possibility that available evidence 
identified by the requestor would, if established, resolve one or more 
of such issues in favor of the requestor, taking into account 
uncontested claims or facts to the contrary; and resolution of the 
factual issues in the manner sought by the requestor would be adequate 
to justify the action requested (40 CFR 178.32). Information submitted 
in connection with an objection or hearing request may be claimed 
confidential by marking any part or all of that information as 
Confidential Business Information (CBI). Information so marked will not 
be disclosed except in accordance with procedures set forth in 40 CFR 
part 2. A copy of the information that does not contain CBI must be 
submitted for inclusion in the public record. Information not marked 
confidential may be disclosed publicly by EPA without prior notice.

VIII. Public Docket

    EPA has established a record for this rulemaking under docket 
control number [OPP-300525] (including any comments and data submitted 
electronically). A public version of this record, including printed, 
paper versions of electronic comments, which does not include any 
information claimed as CBI, is available for inspection from 8:30 a.m. 
to 4 p.m., Monday through Friday, excluding legal holidays. The public 
record is located in Room 1132 of the Public Information and Records 
Integrity Branch, Information Resources and Services Division (7506C), 
Office of Pesticide Programs, Environmental Protection Agency, Crystal 
Mall #2, 1921 Jefferson Davis Highway, 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 tolerances under FFDCA section 408(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,

[[Page 43291]]

entitled Protection of Children from Environmental Health Risks and 
Safety Risks (62 FR 19885, April 23, 1997).
    In addition, since these tolerances and exemptions that are 
established under FFDCA section 408 (d), such as the tolerances in this 
final rule, do not require the issuance of a proposed rule, the 
requirements of the Regulatory Flexibility Act (RFA) (5 U.S.C. 601 et 
seq.) do not apply. Nevertheless, the Agency has previously assessed 
whether establishing tolerances, exemptions from tolerances, raising 
tolerance levels or expanding exemptions might adversely impact small 
entities and concluded, as a generic matter, that there is no adverse 
economic impact. The factual basis for the Agency's generic 
certification for tolerance actions 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: August 5, 1997.

Peter Caulkins,

Acting Director, Registration Divison, 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. 180.434, in the table to paragraph (b), by removing the 
entries for ``grain sorghum,'' and ``grain sorghum stover,'' and by 
adding entries for ``sorghum, aspirated grain fractions,'' ``sorghum, 
grain, grain,'' and ``sorghum, grain, stover,'' to read as follows:


Sec. 180.434  1-[[2-(2,4-dichlorophenyl)-4-propyl-1,3-dioxolan-2-
yl]methyl]-1H-1,2,4-triazole; tolerances for residues.

*       *       *      *      *
    (b) * * *

                                                                        
------------------------------------------------------------------------
                                                          Expiration/   
            Commodity              Parts per million    Revocation Date 
------------------------------------------------------------------------
                                                                        
                  *        *        *        *        *                 
Sorghum, aspirated grain          20                  July 31, 1998     
 fractions.                                                             
Sorghum, grain, grain...........  0.2                 July 31, 1998     
Sorghum, grain, stover..........  1.5                 July 31, 1998     
------------------------------------------------------------------------

*       *       *       *        *
[FR Doc. 97-21145 Filed 8-12-97; 8:45 am]
BILLING CODE 6560-50-F