[Federal Register Volume 63, Number 194 (Wednesday, October 7, 1998)]
[Rules and Regulations]
[Pages 53837-53844]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-26908]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[OPP-300737; FRL 6036-2]
RIN 2070-AB78


Pyridate; Pesticide Tolerance

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This regulation establishes a permanent tolerance for combined 
residues of pyridate, O-(6-chloro-3-phenyl-4-pyridazinyl)-S-octyl 
carbonothioate and its metabolite 6-chloro-3-phenyl-pyridazine-4-ol 
(known as CL-9673), and conjugates of CL-9673, expressed as pyridate, 
in or on chickpeas (also known as garbanzo beans). The tolerance was 
requested by the Interregional Research Project 4 (IR-4) under the 
Federal Food, Drug, and Cosmetic Act (FFDCA), as amended by the Food 
Quality Protection Act of 1996.

DATES: This regulation is effective October 7, 1998. Objections and 
requests for hearings must be received by EPA on or before December 7, 
1998.

ADDRESSES: Written objections and hearing requests, identified by the 
docket control number, OPP-300737, 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-300737, must also be submitted to: Public Information and 
Records Integrity Branch, Information Resources and Services Division 
(7502C), Office of Pesticide Programs, Environmental Protection Agency, 
401 M St., SW., Washington, DC 20460. In person, bring a copy of 
objections and hearing requests to Rm. 119, Crystal Mall #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

[[Page 53838]]

on disks in WordPerfect 5.1/6.1 or ASCII file format. All copies of 
objections and hearing requests in electronic form must be identified 
by the docket control number OPP-300737. 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: Sidney Jackson, 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) 305-7610, e-mail: 
[email protected].

SUPPLEMENTARY INFORMATION: In the Federal Register of August 5, 1998 
(63 FR 41835) (FRL 6017-1) EPA, issued a notice 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 
Interregional Research Project 4 (IR-4). This notice included a summary 
of the petition prepared by Novartis Crop Protection, Inc. , the 
registrant.
    The petition requested that 40 CFR 180. 462 be amended by 
establishing a tolerance for combined residues of the fungicide 
pyridate, O-(6-chloro-3-phenyl-4-pyridazinyl)-S-octyl carbonothioate 
and its metabolite 6-chloro-3-phenyl-pyridazine-4-ol (known as CL-
9673), and conjugates of CL-9673, expressed as pyridate, in or on 
chickpeas at 0.1 part per million (ppm).

I. Risk Assessment and Statutory Findings

    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. ''
    EPA performs a number of analyses to determine the risks from 
aggregate exposure to pesticide residues. For further discussion of the 
regulatory requirements of section 408 and a complete description of 
the risk assessment process, see the Final Rule on Bifenthrin Pesticide 
Tolerances November 26, 1997 (62 FR 62961) (FRL 5754-7).

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 pyridate 
and to make a determination on aggregate exposure, consistent with 
section 408(b)(2), for a tolerance for combined residues of pyridate, 
O-(6-chloro-3-phenyl-4-pyridazinyl)-S-octyl carbonothioate and its 
metabolite 6-chloro-3-phenyl-pyridazine-4-ol (known as CL-9673), and 
conjugates of CL-9673, expressed as pyridate on chickpeas at 0.1 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 pyridate are 
discussed below.
    1. Acute toxicity. The required battery of acute toxicity studies 
has been submitted and found adequate. The findings were as follows: 
oral toxicity shows a lethal dose (LD)50, 5,993 milligrams 
(mg) / kilogram (kg) (males), and LD50, 3,544 mg/kg 
(females) for a Category III toxicant classification; acute dermal 
toxicity is a LD50 > 2,000 mg/kg (Toxicity Category III); 
acute inhalation toxicity shows a lethal concentration 
(LC)50 > 4.37 mg/liter (L) (four hour exposure) (Toxicity 
Category IV); primary eye irritation is Toxicity. Category IV, non-
irritant; Primary Dermal Irritation is slightly irritating to the skin 
under conditions of test (Toxicity Category III); and dermal 
sensitization is positive for skin sensitizer.
    2. Genotoxicity. Test results show pyridate does not elicit a 
mutagenic response in multiple assays. In Gene Mutation Assay (Ames 
Test), no appreciable increase in the reversion to histidine protrophy 
of 4 S. typhimurium strains at 1 to 10,000 micrograms (g)/
plate with and without S-9 activation. Gene Mutation Assay in mammalian 
cells shows pyridate to be nonclastogenic in Chinese Hamster Ovary 
Cells with and without metabolic activation up to 250 g/mL.
    Structural Chromosomal Aberration Assay In vivo cytogenetics did 
not induce chromosomal aberrations nonclastogenic with and without 
metabolic activation under the conditions of the study up to 4 grams/
kg. Nonclastogenic in chromosomal aberrations in bone marrow cells 
sampled over the entire mitotic cycle at doses from 0.073 to 0.725 
grams/mL resulted in a second such assay.
     An Unscheduled DNA Synthesis Assay did not induce an increase in 
unscheduled DNA synthesis up to toxic dose (0.1-1000 g/mL 
tested).
     3. Reproductive and developmental toxicity--i. In a prenatal 
developmental toxicity study in Wistar/HAN rats, pyridate in 
carboxymethyl cellulose was administered at doses of 0, 55, 165, or 400 
mg/kg/day by gavage on gestation days 6-15. For maternal toxicity, the 
No observed adverse effect level (NOAEL) was 165 mg/kg/day and the 
Lowest observed adverse effect level (LOAEL) was 400 mg/kg/day based on 
mortality, significant decrease in mean body weight and food 
consumption as well as clinical signs (ventral body position, dyspnea, 
sedation, and loss of reaction to external stimuli). The developmental 
NOAEL was 165 mg/kg/day and the developmental LOAEL was 400 mg/kg/day, 
based on increased incidences of missing and/or unossified sternebrae 
and dose-related decrease in mean fetal body weight.
    ii. Developmental toxicity. Technical 89.5% pyridate was 
administered in a prenatal developmental toxicity study conducted in 
pregnant New Zealand white rabbits at doses by gavage of 0, 150, 300 or 
600 mg/kg/day on gestation days 7-19. For maternal toxicity, the NOAEL 
was 300 mg/kg/day and the LOAEL was 600 mg/kg/day, based on decreased 
body weight and body weight gain, decreased food consumption, increased 
incidence of dried feces, and increased abortions. For developmental 
toxicity, the NOAEL  was 600 mg/kg/day, the highest dose 
tested (HDT); a LOAEL was not established.
    iii. Three-generation reproduction study. Sprague-Dawley rats 
received diets containing pyridate at doses of 0,

[[Page 53839]]

43, 216 or 1,350 ppm (0, 2.2, 10.8 or 67.5 mg/kg/day, respectively). 
Each generation of rats was mated to produce two litters. The parental 
systemic NOAEL was 216 ppm (10.8 mg/kg/day) and the LOAEL was 1,350 ppm 
(67.5 mg/kg/day) based on depression of maternal body weight gain. The 
NOAEL for offspring was 216 ppm (10.8 mg/kg/day) and the LOAEL was 
1,350 ppm (67.5 mg/kg/day) based on decreased pup weight gains (at 
postnatal and day 14 and 21 in the first litters for both generations).
    The oral rat and rabbit developmental studies and the oral rat 
reproduction study demonstrated no indication of increased sensitivity 
of rats or rabbits to in utero and postnatal exposure to pyridate.
    4. Subchronic toxicity--i. Subchronic feeding in rats (13 weeks) 
resulted in hypoactivity and salivation in both sexes with a NOAEL = 
62.5 mg/kg/day and the LOAEL at 177 mg/kg/day.
     ii. A subchronic feeding in dogs (13 weeks) showed a NOAEL at 20 
mg/kg/day and the LOAEL at 60 mg/kg/day based on emesis and ataxia in 
both sexes. Severe neurotoxicity and death were observed at 200 mg/kg/
day (HDT).
    iii. In a 21-day dermal study in rats, the NOAEL for systemic 
effects was > 1,000 mg/kg/day limit dose. No systemic toxicity was seen 
at any dose tested. A LOAEL for systemic effects was not established in 
this study.
    5. Chronic toxicity/carcinogenicity--i. Technical (91.5%) pyridate 
material was fed by capsule to 5 dogs/group/dose at levels of 0, 5/30, 
20/100, or 60/150 mg/kg/day for one year. A LOAEL of 100 mg/kg/day was 
based on excessive salivation, ataxia, mydriasis, dyspnea, tremors, 
increased respiration and prostration. The NOAEL is 20 mg/kg/day.
     ii. Carcinogenicity study in mice. Technical (90.4%) pyridate test 
material was given to male and female B6C3F1 mice in diet for 18 months 
at 0, 400, 800, 1,600 ppm or 7,000 ppm; (0, 47.7, 97.1, 169.5, or 882.6 
mg/kg/day for males; 0, 54.5, 114.6, 204.3, or 1,044.6 mg/kg/day for 
females. No statistically significant increase in tumor incidence 
relative to controls were observed in either sex at any dose, including 
the limit dose 7,000 ppm. Neither the NOAEL or the LOAEL could be 
established due to decreased weight gain in both sexes at all doses.
     iii. Chronic feeding/carcinogenicity study in rats. Technical 
(90.3%) pyridate was administered to male and female SPF rats in diet 
for 24 months at 0, 43, 215 and 1,350 ppm; (0, 2.2, 10.8 or 67.5 mg/kg/
day). Decrease in body weight in males at 67.5 mg/kg/day was basis of 
the LOAEL. NOAEL is 10.8 mg/kg/day.
     6. Metabolism in rats. Following is a summary of rat metabolism 
values and categories for pyridate:
     i. Rapidly absorbed and excreted. Greater than 95% was eliminated 
by 24 hrs. Extensively metabolized prior to excretion. Metabolic 
patterns similar for both sexes.
    ii. Completely and rapidly absorbed. Extensively metabolized and 
rapidly and essentially completely excreted. Elimination of label from 
single dose of 5.45 mg/rat of C14-pyridate.
    iii. Multiple oral doses 5 mg/rat/day for 10, 15, or 20 days result 
in bioaccumulation in liver, spleen and fat. Clearance from all tissues 
was slower after repeated exposure. Female rats eliminated 
radioactivity slower than males.
     7. Neurotoxicity. Neurotoxicity was observed in the 90 day rat and 
dog studies and the 1-year dog study. Clinical signs indicative of 
neurotoxicity characterized as ataxia and emesis were observed within 
1-3 hours post-dosing on the first day and persisted for duration of 
study.

B. Toxicological Endpoints

     1. Acute toxicity. The acute dietary endpoint selected for risk 
assessment was the NOAEL of 20 mg/kg/day based on test results where 
groups of beagle dogs (4/sex/dose) received gelatin capsules containing 
pyridate at doses of 0, 20, 60 or 200 mg/kg/day for 90 days. The LOAEL 
was 60 mg/kg/day based on ataxia and emesis observed within 1-3 hours 
dosing beginning on the first day. All dogs at 200 mg/kg/day exhibited 
severe emesis and severe ataxia 1 to 3 hours post dosing and signs of 
opisthotonos, nystagmus and mydriasis also occurred within 3 hours 
after dosing.
     2. Short - and intermediate - term toxicity. The short- and 
intermediate- term endpoints are derived from a 90-day feeding study in 
dogs. The NOAEL for both short- and intermediate-term exposures is 20 
mg/kg/day.
    Although a 21-day dermal toxicity study in rats was available and 
no dermal or systemic toxicity was demonstrated in that study at the 
Limit-Dose, an oral dose from the 90-day dog study was selected for 
short- and intermediate-term endpoints because:
    i. Dogs were shown to be the sensitive species for pyridate-induced 
neurotoxic effects.
    ii. The effects seen on the first day persisted for the duration of 
study. Since an oral dose was selected, a dermal absorption rate no 
more than 20% is used for risk assessments.
    For short-and intermediate-term inhalation exposure, pyridate, 
based on the LC50 value of 4.37 mg/L, is placed in Toxicity 
Category IV. An inhalation risk assessment may not be required. This is 
supported by the absence of residential uses of pyridate.
    Since only an acute inhalation toxicity study was available, EPA 
used oral NOAELs for the inhalation exposure risk assessments. Because 
of the low acute inhalation toxicity of pyridate, and minimal 
volatility (vapor pressure of pyridate is 1.01 x 10-7 mm 
mercury (Hg), inhalation exposure is considered very low (less than 6%) 
to occupational workers. For this reason, an inhalation MOE for workers 
was not calculated.
    There are currently no residential uses for pyridate and no 
residential exposure study was performed. The Agency concludes that no 
risk assessment for short- and intermediate-term risk is required.
     3. Chronic toxicity. EPA has established the RfD for pyridate at 
0.11 mg/kg/day. This RfD is based on a study where rats (15/sex/dose) 
were fed diets containing pyridate 0, 2.2, 10.8 or 67.5 mg/kg/day for 
104 weeks. The NOAEL was 10.8 mg/kg/day and the LOAEL 67.5 mg/kg/day 
based on decreased body weight gain in males. For chronic dietary risk 
assessment, an uncertainty factor (UF) of 100 is adequate for the 
protection of all subpopulation from exposure to pyridate.
     4. Carcinogenicity. Pyridate is classified as Category E, a non-
carcinogen, based on studies from two acceptable animals studies which 
showed no significant increase in tumor incidence in male or in female 
test animals at dose levels up to 7,000 ppm.

C. Exposures and Risks

    1. From food and feed uses. Tolerances have been established (40 
CFR 180.462) for the combined residues of pyridate, O-(6-chloro-3-
phenyl-4-pyridazinyl)-S-octyl carbonothioate and its metabolite 6-
chloro-3-phenyl-pyridazine-4-ol (known as CL-9673), and conjugates of 
CL-9673 expressed as pyridate, in or on a variety of raw agricultural 
commodities. Permanent tolerances are established for residues of 
pyridate (40 CFR 180.462) on cabbage, corn (forage, fodder, grain, 
silage), and peanuts (hulls, nutmeat) at 0.03 ppm. There are no food or 
feed additive tolerances. No tolerances have been established on animal 
commodities. Pyridate is not registered for outdoor residential or 
greenhouse uses. Risk assessments were conducted by EPA to assessed 
dietary exposures from pyridate as follows:

[[Page 53840]]

     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.
    2.  Acute exposure and risk. Acute dietary risk assessments are 
performed for a food-use pesticide if a toxicological study has 
indicated the possibility of an effect of concern occurring as a result 
of a one day or single exposure. The endpoint selected by the Agency 
for assessment of acute dietary risk is 20 mg/kg/day (NOAEL), based on 
a 90-day feeding study in dogs. This acute dietary (food) risk 
assessment assumed that all food for which there are tolerances would 
have residues at the tolerance level. Using the acute endpoint, NOAEL 
(mg/kg/day) and these exposure assumptions margin of exposure (MOE) for 
subgroups can be calculated as follows:

     MOE = Acute Endpoint (NOAEL, mg/kg/day) / Exposure (TMRC, mg/kg/
day)

    For the U.S. Population (48 states) subgroup, the MOE is 100,000. 
For Infants, < 1 year old, the most highly exposed subgroup, the MOE is 
40,000. All population subgroups show a MOE well above the critical 
level, MOE = 100, for which the Agency is concerned. The Agency 
concludes that there is reasonable certainty that public health will 
not be harmed by acute exposure and risk from pyridate uses at the 
proposed tolerance levels. This is due to the conservative assumptions 
leading to the overestimation of pyridate acute dietary exposure.
    3. Chronic exposure and risk. The chronic dietary exposure analysis 
from food sources was conducted using the reference dose (RfD) of 0.11 
mg/kg/day. The RfD is based on the NOAEL of 10.8 mg/kg/day in male rats 
from the chronic toxicity/carcinogenicity study in rats, and an 
uncertainty factor of 100 applicable to all population subgroups.
    In conducting this chronic dietary risk assessment, EPA has made 
very conservative assumptions: 100% of chickpeas and all other 
commodities having pyridate tolerances will contain pyridate residues 
at the level of the established tolerance. This results in an 
overestimate of human dietary exposure. Thus, in making a safety 
determination for this tolerance, EPA is taking into account this 
conservative exposure assessment.
    The existing pyridate tolerances (published, pending, and including 
the necessary section 18 tolerances) result in exposure that is 
equivalent to the following percentages of the RfD:

------------------------------------------------------------------------
            Population Subgroup                          %RfD
------------------------------------------------------------------------
U.S. Population (48 states)...............   0.014
Nursing Infants < 1 year old..............  0.009
Non-Nursing Infants.......................  0.028 < 1 year old
Children 1-6 years old....................   0.033
Children 7-12 years old...................   0.025
Southern Region...........................   0.016
Western Region............................   0.015
Hispanics.................................   0.018
Non-Hispanic Others.......................   0.020
Males 13-19 years old.....................   0.015
------------------------------------------------------------------------

    The subgroups listed above are:
    i. The U.S. population (48 states).
    ii. Those for infants and children.
    iii. The other subgroups for which the percentage of the RfD 
occupied is greater than that occupied by the subgroup U.S. population 
(48 states).
    4. From drinking water. The generic expected environmental 
concentration (GENEEC) model and the SCI-GROW model were run to produce 
estimates of pyridate concentrations in surface and ground water 
respectively. The primary use of these models is to provide a coarse 
screen for sorting out pesticides for which EPA has a high degree of 
confidence that the true levels of the pesticide in drinking water will 
be less than the human health drinking water levels of concern 
(DWLOCs). A human health DWLOC is the concentration of a pesticide in 
drinking water which would result in unacceptable aggregate risk, after 
having already factored in all food exposures and other non-
occupational exposures for which EPA has reliable data.
    5. Acute and chronic exposure and risk. The calculated drinking 
water levels of concern (DWLOCs) for acute exposure to pyridate in 
surface and ground water are 7,000 g/liter(L) for all 3 
population subgroups evaluated. For chronic (non-cancer) exposure to 
pyridate in surface and ground water, the DWLOCs are 3,850 g/L 
for males (13 yrs+), 3,300 g/L for females (13 yrs+) and 1,100 
g/L for children (1-6 yrs). To calculate the DWLOC for acute 
exposure relative to an acute toxicity endpoint, the acute dietary food 
exposure (from the dietary risk evaluation system (DRES) analysis) was 
subtracted from the ratio of the acute NOAEL (used for acute dietary 
assessments) to the ``acceptable'' for aggregate exposure to obtain the 
acceptable acute exposure to pyridate in drinking water. To calculate 
the DWLOC for chronic (non-cancer) exposure relative to a chronic 
toxicity endpoint, the chronic dietary food exposure from DRES was 
subtracted from the RfD to obtain the acceptable chronic (non-cancer) 
exposure to pyridate in drinking water. DWLOCs were then calculated 
using default body weights and drinking consumption figures.
    Estimated Environmental Concentrations (EEC) of pyridate in surface 
and ground water are 97 and 5 ppb respectively. Estimated average 
concentrations of pyridate in surface and ground water are 25 (after 
adjustment) and 5 ppb respectively. The EEC of pyridate in surface and 
ground water are less than EPA's levels of concern for pyridate in 
drinking water as a contribution to acute and chronic aggregate 
exposure. Therefore, EPA concludes with reasonable certainty that 
residues of pyridate in drinking water (when considered along with 
other sources of exposure for which EPA has reliable data) would not 
result in unacceptable levels of aggregate human health risk.
     6. From non-dietary exposure. Pyridate is not currently registered 
for use on any the following residential non-food sites. Pyridate is 
not registered for outdoor residential or greenhouse uses, therefore, 
no residential exposure study is required. Although it is shown to be a 
skin sensitizer, all other required acute toxicological studies placed 
pyridate in either Toxicity Categories III or IV, representing a low 
level toxicant. Pyridate has a complete toxicological data base and no 
other concerns regarding acute toxicity have been identified.
    Occupational exposure estimates for pyridate did not exceed the 
Agency's level of concern. However, due to potential for exposure, risk 
assessments are being required for short- and intermediate-term dermal 
exposure, as well as, short-, intermediate, and long-term exposure. A 
long-term risk assessment would be required if a long-term exposure 
senarios were present.

[[Page 53841]]

 However, at this time, pyridate is not used in any long-term senarios.
    7. Short- and intermediate-term exposure and risk. The short and 
intermediate occupational and residential endpoint selected for risk 
assessment was the NOAEL of 20 mg/kg/day based on ataxia and emesis at 
60 mg/kg/day as determined by a 90-day dog feeding study..
    A dermal absorption study was not available for evaluation. 
Although a 21-day dermal toxicity study in rats was available and no 
dermal or systemic toxicity was demonstrated in that study at the 
Limit-Dose (1,000 mg/kg/day), an oral dose from the 90-day dog study 
was selected because:
    i. Dogs were shown to be the sensitive species for pyridate-induced 
neurotoxic effects.
    ii. The effects seen on the first day persisted for the duration of 
study. The Agency estimated a dermal absorption rate of 20% percent 
based on the interpretation of data from oral and dermal studies in 
rats.
    8.  Inhalation exposure. In general, a risk assessment for 
inhalation route is not necessary for pesticides placed in Toxicity 
Category IV (i.e., low toxicity concern). Pyridate, based on the 
LC50 value of 4.37 mg/L is placed in Toxicity Category IV. 
However, because of the potential for exposure via this route, a risk 
assessment may be required. Since only an acute inhalation toxicity 
study was available, the Agency relies on the oral NOAELs for the 
inhalation exposure risk assessments.
    Since only an acute inhalation toxicity study was available, the 
oral NOAELs for the inhalation exposure risk assessments were used. The 
90-day dog feeding study was chosen for short-and intermediate-term 
inhalation exposure. NOAEL = 20 mg/kg/day and the chronic toxicity/
carcinogenicity rat feeding study was chosen for long-term inhalation 
exposure. NOAEL = 10.8 mg/kg/day.
    9. 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.''
    EPA does not have, at this time, available data to determine 
whether pyridate 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, 
pyridate 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 pyridate has a common mechanism of toxicity 
with other substances. For information regarding EPA's efforts to 
determine which chemicals have a common mechanism of toxicity and to 
evaluate the cumulative effects of such chemicals, see the Final Rule 
for Bifenthrin Pesticide Tolerances November 26, 1997 (62 FR 62961) 
(FRL 5754-7).

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

    1. Acute risk. From the acute dietary (food only) risk assessment, 
the following high end exposure estimates were calculated: 0.00018 mg/
kg/day for the general U.S population; 0.00012 mg/kg/day for males (13 
+ yrs); 0.00012 mg/kg/day for females (13 + years); 0.0005 mg/kg/day 
for infants (< 1 yr); 0.0003 mg/kg/day for children (1-6 yrs). These 
exposures yield dietary (food only) MOEs ranging from 40,000 to 170,000 
for these population subgroups. The maximum estimated concentrations of 
pyridate in surface and ground water are less than EPA's levels of 
concern for pyridate in drinking water as a contribution to acute 
aggregate exposure. Therefore, EPA concludes with reasonable certainty 
that residues of pyridate in drinking water do not contribute 
significantly to the aggregate acute human health risk at the present 
time when considering the present uses and the uses proposed by this 
action. Thus, the aggregate acute risk (food and water) is not expected 
to exceed the Agency level of concern for acute dietary exposure.
    2. Chronic risk. Using the TMRC exposure assumptions described 
above, EPA has concluded that aggregate exposure to pyridate from food 
will utilize 0.014% of the RfD for the U.S. population. The major 
identifiable subgroup with the highest aggregate exposure is 
``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 pyridate 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 chronic aggregate exposure to pyridate residues.
    3. Short- and intermediate-term risk. Pyridate is not currently 
registered for any residential uses. Therefore, no residential exposure 
(short- or intermediate-term) is anticipated and a short- and 
intermediate-term aggregate risk assessment is not required.
    Short- and intermediate-term aggregate exposure takes into account 
chronic dietary food and water (considered to be a background exposure 
level) plus indoor and outdoor residential exposure. For the U.S. 
population, 0.014% of the RfD is occupied by dietary (food) exposure. 
Because pyridate has no residential uses, no chronic residential 
exposure is anticipated. The estimated average concentrations of 
pyridate in surface and ground water are less than EPA's level of 
concern for pyridate in drinking water as a contribution to chronic 
aggregate exposure. Therefore, EPA concludes with reasonable certainty 
that residues of pyridate in drinking water do not contribute 
significantly to the short- and intermediate-term aggregate human 
health risk at the present time when considering the present uses and 
uses proposed by this action.

4. Aggregate cancer risk for U.S. population. Pyridate has been 
classified as a Group E chemical, with no evidence of carcinogenicity 
for humans in two acceptable animal (mouse and rat) studies. Thus, a 
cancer risk assessment is not required.

    5. Determination of safety. Based on these risk assessments, EPA 
concludes that there is a reasonable certainty that no harm will result 
from aggregate exposure to pyridate residues.

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

    1. Safety factor for infants and children --In general. In 
assessing the potential for additional sensitivity of infants and 
children to residues of pyridate, EPA considered data from 
developmental toxicity studies in the rat and rabbit and a 2-generation 
reproduction study in the r at. The developmental toxicity studies are 
designed to evaluate adverse effects on the developing organism 
resulting from maternal pesticide exposure 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

[[Page 53842]]

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 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.
    2. Pre- and post-natal sensitivity. The oral perinatal and prenatal 
data demonstrated no indication of increased sensitivity of rats or 
rabbits to in utero and postnatal exposure to pyridate.
    3. Conclusion. There is a complete toxicity database for pyridate 
and exposure data are complete or estimated based on data that 
reasonably account for potential exposures. EPA concludes that reliable 
data support removal of the additional tenfold safety factor.
    4. Acute risk. The acute dietary endpoint selected for risk 
assessment was the NOAEL of 20 mg/kg/day based on a 90-day feeding 
study in dogs.
    From the acute dietary (food only) risk assessment, risk 
calculations for infants <1 yr old is 0.0005 mg/kg/day and 0.0003 mg/
kg/day for children (1-6 yrs). These exposures yield dietary (food 
only) MOEs of 40,000 and 70,000, respectively, for these population 
subgroups.
    The maximum estimated concentrations of pyridate in surface and 
ground water are less than EPA's levels of concern for pyridate in 
drinking water as a contribution to acute aggregate exposure. 
Therefore, EPA concludes with reasonable certainty that residues of 
pyridate in drinking water do not contribute significantly to the 
aggregate acute human health risk at the present time when considering 
the present uses and the uses proposed by this action.
    EPA's bases this determination on a comparison of estimated 
concentrations of pyridate in surface and ground water to levels of 
concern for pyridate in drinking water. The estimates of pyridate in 
surface and ground water are derived from water quality models that use 
conservative assumptions regarding the pesticide transport from the 
point of application to surface and ground water. Because EPA considers 
the aggregate risk resulting from multiple exposure pathways associated 
with the pesticide's uses, levels of concern in drinking water may vary 
as those uses change. If new uses are added in the future, EPA will 
reassess the potential impact of pyridate in drinking water as part of 
the aggregate acute risk assessment process.
    5. Chronic risk. Using the exposure assumptions described above, 
EPA has concluded that aggregate exposure to pyridate from food will 
utilize 0.033% of the RfD for infants and children. 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 pyridate in drinking water and 
from non-dietary, non-occupational exposure, EPA does not expect the 
chronic aggregate exposure to exceed 100% of the RfD.
    6. Short- or intermediate-term risk. Pyridate is not registered for 
residential use. No residential exposure or short- or intermediate-term 
risk is therefore expected. A short- and intermediate-term risk 
assessment is not required.
    7. Determination of safety. Based on these risk assessments, EPA 
concludes that there is a reasonable certainty that no harm will result 
to infants and children from aggregate exposure to pyridate residues.

III. Other Considerations

A. Metabolism In Plants and Animals

     The metabolism of pyridate in plants is well understood based on 
studies with broccoli, corn, and peanuts. Pyridate is rapidly broken 
down by hydrolysis and further conjugated to glucoside and degraded. 
Adequate acceptable metabolism studies have also been conducted in 
lactating goats, cows and laying hens.
    Based on those studies, the nature of the residue in plants and 
ruminants is considered to be adequately understood. The total toxic 
residue consists of pyridate, its metabolite 6-chloro-3-phenyl-
pyridazine-4-ol CL-9673, and conjugates of that metabolite, all 
expressed as pyridate.

B. Analytical Enforcement Methodology

     The residue analytical method used is a total residue procedure. 
Pyridate, CL-9673, and conjugated CL-9673 are hydrolyzed to CL-9673 and 
measured as such by UV-HPLC. The limit of determination is 0.03 ppm. 
The method has undergone validation in EPA laboratories and is suitable 
to gather residue data and to enforce tolerances. It was sent to FDA 
for inclusion in PAM II. The multi residue recovery data have been sent 
for inclusion in PAM I.

C. Magnitude of Residues

     Results from field studies show that the maximum residue pyridate, 
CL-9673, and hydrolyzable CL-9673 in sum, expressed as CL-9673 
recovered in any bean sample from garbanzo plants treated twice at the 
proposed label rate of 0.9 lbs ai/A was 0.057 ppm. The maximum pyridate 
residue recovered in bean plus hull samples from garbanzo plants 
treated twice at the proposed label rate of 0.9 lbs ai/A was < 0.030 
ppm.
    The maximum residue (pyridate, CL-9673, and hydrolyzable CL-9673 in 
sum, expressed as CL-9673) recovered in any bean sample from garbanzo 
plants treated twice at the proposed label rate of 1.8 lbs ai/A was < 
0.030 ppm. The maximum pyridate residue recovered in bean plus hull 
samples from garbanzo plants treated twice at the proposed label rate 
of 1.8 lbs ai/A was < 0.030 ppm. Therefore, the combined residues of 
pyridate O-(6-chloro-3-phenyl-4-pyridazinyl)-S-octyl-carbonothioate, 
the metabolite 6-chloro-3-phenyl-pyridazine-4-ol and conjugates of 6-
chloro-3-phenyl-pyridazine-4-ol, expressed as pyridate resulting from 
the proposed use will not exceed 0.1 ppm in chickpeas.
    Pyridate is not registered of direct use on potable water, aquatic 
food and feed crops, or for use in food handling establishments. 
Moreover, there are no processed commodities and no animal feed items 
associated with chickpeas.

D. International Residue Limits

    There are no CODEX, Canadian, or Mexican tolerances for pyridate 
residues on chickpeas.

E. Rotational Crop Restrictions

     A confined accumulation in rotational crops study with pyridate 
has previously been submitted to the Agency. Confined rotational crop 
data using 14C-pyridate at an application rate of 1.8 kg/ha 
showed no detectable uptake (<0.01 ppm) of residues of pyridate by 
lettuce, carrots, or barley after a rotational interval of 1 and 2 
months. These findings were supported by data showing the rapid 
metabolism in soil of pyridate residues.

IV. Conclusion

    Therefore, the tolerance is established for combined residues of 
pyridate, O-(6-chloro-3-phenyl-4-pyridazinyl)-S-octyl carbonothioate 
and its metabolite 6-chloro-3-phenyl-pyridazine-4-ol (known as CL-
9673), and conjugates of CL-9673, expressed as pyridate, in or on 
chickpeas at 0.1 ppm.

[[Page 53843]]

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 December 7, 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 or a request for 
a fee waiver as specified by 40 CFR 180.33. 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.

VI. Public Record and Electronic Submissions

    EPA has established a record for this rulemaking under docket 
control number OPP-300737 (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 119 of the Public Information and Records 
Integrity Branch, Information Resources and Services Division (7502C), 
Office of Pesticide Programs, Environmental Protection Agency, Crystal 
Mall #2, 1921 Jefferson Davis Hwy., Arlington, VA.
    Electronic comments may be sent directly to EPA at:
    [email protected].

    Electronic comments must be submitted as an ASCII file avoiding the 
use of special characters and any form of encryption.
    The official record for this rulemaking, as well as the public 
version, as described above will be kept in paper form. Accordingly, 
EPA will transfer any copies of objections and hearing requests 
received electronically into printed, paper form as they are received 
and will place the paper copies in the official rulemaking record which 
will also include all comments submitted directly in writing. The 
official rulemaking record is the paper record maintained at the 
Virginia address in ``ADDRESSES'' at the beginning of this document.

VII. Regulatory Assessment Requirements

A. Certain Acts and Executive Orders

    This final rule establishes tolerances 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 tolerances and exemptions that are established 
on the basis of a petition 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.

B. Executive Order 12875

    Under Executive Order 12875, entitled Enhancing the 
Intergovernmental Partnership (58 FR 58093, October 28, 1993), EPA may 
not issue a regulation that is not required by statute and that creates 
a mandate upon a State, local, or tribal government, unless the Federal 
government provides the funds necessary to pay the direct compliance 
costs incurred by those governments. If the mandate is unfunded, EPA 
must provide to OMB a description of the extent of EPA's prior 
consultation with representatives of affected State, local, and tribal 
governments, the nature of their concerns, copies of any written 
communications from the governments, and a statement supporting the 
need to issue the regulation. In addition, Executive Order 12875 
requires EPA to develop an effective process permitting elected 
officials and other representatives of State, local, and tribal 
governments ``to provide meaningful and timely input in the development 
of regulatory proposals containing significant unfunded mandates.''
    Today's rule does not create an unfunded Federal mandate on State, 
local, or tribal governments. The rule

[[Page 53844]]

does not impose any enforceable duties on these entities. Accordingly, 
the requirements of section 1(a) of Executive Order 12875 do not apply 
to this rule.

C. Executive Order 13084

    Under Executive Order 13084, entitled Consultation and Coordination 
with Indian Tribal Governments (63 FR 27655, May 19,1998), EPA may not 
issue a regulation that is not required by statute, that significantly 
or uniquely affects the communities of Indian tribal governments, and 
that imposes substantial direct compliance costs on those communities, 
unless the Federal government provides the funds necessary to pay the 
direct compliance costs incurred by the tribal governments. If the 
mandate is unfunded, EPA must provide to OMB, in a separately 
identified section of the preamble to the rule, a description of the 
extent of EPA's prior consultation with representatives of affected 
tribal governments, a summary of the nature of their concerns, and a 
statement supporting the need to issue the regulation. In addition, 
Executive Order 13084 requires EPA to develop an effective process 
permitting elected officials and other representatives of Indian tribal 
governments ``to provide meaningful and timely input in the development 
of regulatory policies on matters that significantly or uniquely affect 
their communities.''
    Today's rule does not significantly or uniquely affect the 
communities of Indian tribal governments. This action does not involve 
or impose any requirements that affect Indian tribes. Accordingly, the 
requirements of section 3(b) of Executive Order 13084 do not apply to 
this rule.

VIII. Submission to Congress and the Comptroller General

    The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the 
Small Business Regulatory Enforcement Fairness Act of 1996, generally 
provides that before a rule may take effect, the agency promulgating 
the rule must submit a rule report, which includes a copy of the rule, 
to each House of the Congress and to the Comptroller General of the 
United States. EPA will submit 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 United States prior 
to publication of the rule in the Federal Register. This rule 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: September 29, 1998.

James Jones,

Director, Registration Division, Office of Pesticide Programs.
    Therefore, 40 CFR chapter I is amended as follows:

PART 180 -- [AMENDED]

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

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

    2. Sec. 180.462, is amended by adding alphabetically ``chickpeas'' 
to the table in paragraph (a), and by removing and reserving paragraph 
(b) to read as follows:


Sec. 180.462  Pyridate; tolerances for residues.

    (a) General. * * *

------------------------------------------------------------------------
                 Commodity                        Parts per million
------------------------------------------------------------------------
               *      *      *      *      *      *      *
Chickpeas.................................  0.1
               *      *      *      *      *      *      *
------------------------------------------------------------------------

    (b) Section 18 emergency exemptions. [Reserved]
*    *    *    *    *

[FR Doc. 98-26908 Filed 10-6-98; 8:45 am]
BILLING CODE 6560-50-F