[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]
-----------------------------------------------------------------------
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.
-----------------------------------------------------------------------
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