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Spinosad; Pesticide Tolerance
Note: EPA no longer updates this information, but it may be useful as a reference or resource.
[Federal Register: May 26, 1999 (Volume 64, Number 101)]
[Rules and Regulations]
[Page 28363-28370]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr26my99-9]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
OPP-300864; FRL-6081-8]
RIN 2070-AB78
Spinosad; Pesticide Tolerance
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
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SUMMARY: This regulation establishes time-limited tolerances for
residues of spinosad in or on sweet corn at 0.02 parts per million
(ppm), sweet corn forage at 0.6 ppm, sweet corn stover at 1.0 ppm, and
a permanent tolerance for tuberous and corm vegetables (crop subgroup
1C) at 0.02 ppm. The Interregional Research Project Number 4 (IR-4)
requested the tolerance for tuberous and corm vegetables (crop subgroup
1C). Dow AgroScience Company requested tolerances for sweet corn. These
tolerances were requested under the Federal Food, Drug, and Cosmetic
Act, as amended by the Food Quality Protection Act of 1996.
DATES: This regulation is effective May 26, 1999. Objections and
requests for hearings must be received by EPA on or before July 26,
1999.
ADDRESSES: Written objections and hearing requests, identified by the
docket control number, [OPP-300864], 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-300864], must also be submitted to: Public
Information and Records Integrity Branch, Information Resources and
Services Division (7502C), Office of Pesticide Programs, Environmental
[[Page 28364]]
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 be submitted electronically by sending electronic mail (e-
mail) to: opp-docket@epa.gov. Copies of objections and hearing requests
must be submitted as an ASCII file avoiding the use of special
characters and any form of encryption. Copies of objections and hearing
requests will also be accepted on disks in WordPerfect 5.1/6.1 file
format or ASCII file format. All copies of objections and hearing
requests in electronic form must be identified by the docket control
number [OPP-300864]. 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: Rm. 272, Crystal Mall
#2, 1921 Jefferson Davis Hwy., Arlington, VA, (703) 305-7610,
jackson.sidney@epa.gov.
SUPPLEMENTARY INFORMATION: In the Federal Register of April 8, 1999
(64 FR 17174) (FRL-6071-2), EPA issued a notice pursuant to section 408
of the Federal Food, Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 346a as
amended by the Food Quality Protection Act of 1996 (FQPA) (Public Law
104-170) announcing the filing of a pesticide petition (PP) for
tolerance by the Interregional Research Project Number 4 (IR-4), New
Jersey Agricultural Experimental Station: P.O. Box 231, Rutgers
University, New Brunswick, NJ and on September 16, 1998 (63 FR 49568)
(FRL-6025-8) by the Dow AgroScience Company, 9330 Zionsville Road,
Indianapolis, IN 46254. Each notice included a summary of the petition
prepared by Dow AgroSciences, the registrant.
These petitions requested that 40 CFR 180.495 be amended by
establishing tolerances for residues of the insecticide spinosad, in or
on sweet corn at 0.02 ppm, sweet corn forage at 0.6 ppm, sweet corn
stover at 1.0 ppm, and for tuberous and corm vegetables (crop subgroup
1C) at 0.02 ppm. Spinosad is a fermentation product of
Saccharopolyspora spinosa. Spinosad consist of two related spinosyn
compounds, Factor A and Factor D both of which serve as active
ingredients. They are typically present at an 85:15 A:D ratio.
I. Background 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 (62 FR 62961, November 26, 1997) (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 spinosad
and to make a determination on aggregate exposure, consistent with
section 408(b)(2), for tolerances for residues of spinosad on sweet
corn at 0.02 ppm, sweet corn forage at 0.6 ppm, sweet corn stover at
1.0 ppm and a tolerance for tuberous and corm vegetables (crop subgroup
1C) at 0.02 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 spinosad are
discussed in this unit.
1. Acute toxicity. Spinosad has low acute toxicity. The rat oral
lethal dose (LD<INF>50</INF>) is 3,738 milligram(mg)/kilogram(kg) for
males and > 5,000 mg/kg for females, whereas the mouse oral
(LD<INF>50</INF>) is >5,000 mg/kg. The rabbit dermal LD<INF>50</INF> is
>5,000 mg/kg and the rat inhalation lethal concentration
(LC<INF>50</INF>) is >5.18 mg/liter(l) air. In addition, spinosad is
not a skin sensitizer in guinea pigs and does not produce significant
dermal or ocular irritation in rabbits. End use formulations of
spinosad that are water based suspension concentrates have similar low
acute toxicity profiles.
2. Genotoxicity. Short term assays for genotoxicity consisting of
a bacterial reverse mutation assay (Ames test), an in vitro assay for
cytogenetic damage using the Chinese hamster ovary cells, an in vitro
mammalian gene mutation assay using mouse lymphoma cells, an in vitro
assay for DNA damage and repair in rat hepatocytes, and an in vivo
cytogenetic assay in the mouse bone marrow (micronucleus test) have
been conducted with spinosad. These studies show a lack of
genotoxicity.
3. Reproductive toxicity. In a 2-generation reproduction study,
groups of Sprague-Dawley rats (30/sex/group) received diets containing
Spinosad (88.0%) at dose levels of 0, 0.005, 0.02, or 0.2% (3, 10, or
100 mg/kg/day, respectively) for two successive generations. For
parental systemic toxicity, the no-observed adverse effect level
(NOAEL) was 0.02% (10 mg/kg/day) and the lowest-observed adverse effect
level (LOAEL) was 0.2% (100 mg/kg/day), based on increased heart,
kidney, liver, spleen, and thyroid weights (both sexes), histopathology
in the spleen and thyroid (both sexes), heart and kidney (males), and
histopathologic lesions in the lungs and mesenteric lymph nodes (both
sexes), stomach (females), and prostate. For offspring toxicity, the
NOAEL was 0.02% (10 mg/kg/day) and the LOAEL was 0.2% (100 mg/kg/day)
based on decreased litter size, survival (F2), and body weights.
Reproductive effects at that dose level included increased incidence of
dystocia and/or vaginal bleeding after parturition with associated
increase in mortality of dams.
4. Developmental toxicity. In a prenatal developmental toxicity
study, groups of pregnant Sprague-Dawley rats (30/group) received oral
(gavage)
[[Page 28365]]
administration of Spinosad (88.6%) in aqueous 0.5% methylcellulose at
dose levels of 0, 10, 50, or 200 mg/kg/day during gestation days 6
through 17. For maternal toxicity, the NOAEL was >200 mg/kg/day (the
highest dose tested (HDT)); a LOAEL was not established. Marginal
maternal toxicity was reported at this dose level (decreased body
weight gain). Based upon the results of a range-finding study, which
showed maternal toxicity (body weight and food consumption decreases at
100 and 300 mg/kg/day), the dose level of 200 mg/kg/day in the main
study was considered adequate. For developmental toxicity, the NOAEL
was >200 mg/kg/day; a LOAEL was not established. In the range-finding
study, fetal body weight decrements occurred at 300 mg/kg/day.
In a prenatal developmental toxicity study, groups of pregnant New
Zealand White rabbits (20/group) received oral (gavage) administration
of Spinosad (88.6%) in 0.5% aqueous methyl cellulose at doses of 0,
2.5, 10, or 50 mg/kg/day during gestation days 7 through 19. For
maternal toxicity, the NOAEL was <gr-thn-eq>50 mg/kg/day HDT; a LOAEL
was not established. At this dose, slight body weight loss was observed
in the first few days of dosing, but this finding was not supported by
other signs. In the range-finding study, inanition was observed at
doses of 100, 200, and 400 mg/kg/day, with significant decreases in
body weight gain during dosing. All does at these dose levels were
sacrificed prior to scheduled termination; no fetal data were
available. No evidence of developmental toxicity was noted. For
developmental toxicity, the NOAEL was <gr-thn-eq>50 mg/kg/day; a LOAEL
was not established. (No fetal effects were noted for fetuses of the
range-finding study at doses up to 50 mg/kg/day).
5. Subchronic toxicity. Spinosad was evaluated in 13-week dietary
studies and showed NOAELs of 4.89 and 5.38 mg/kg/day, respectively in
male and female dogs; 6 and 8 mg/kg/day, respectively in male and
female mice; and 33.9 and 38.8 mg/kg/day, respectively in male and
female rats. The LOAELs in the male rat and female rat were 68.5 and
78.1 mg/kg/day, respectively based on decreased body weight gain,
anemia, and vacuolation in multiple organs (kidney, liver, heart,
spleen, adrenals, and thyroid). No dermal irritation or systemic
toxicity occurred in a 21-day repeated dose dermal toxicity study in
rats given 1,000 mg/kg/day.
6. Chronic toxicity and carcinogenicity. Based on chronic testing
with spinosad in the dog and the rat, the EPA has set a reference dose
(RfD) of 0.027 mg/kg/day for spinosad. The RfD has incorporated a 100-
fold safety factor to the NOAELs found in the chronic dog study to
account for inter- and intra-species variation. The NOAELs shown in the
dog chronic study were 2.68 and 2.72 mg/kg/day, respectively for male
and female dogs. The NOAELs (systemic) shown in the rat chronic/
carcinogenicity/neurotoxicity study were 9.5 and 12.0 mg/kg/day,
respectively for male and female rats. The LOAEL (systemic) was 24.1
and 30.3 mg/kg/day for males and females, respectively based on
vacuolation of epithelial follicular cells of the thyroid.
Using the Guidelines for Carcinogen Risk Assessment published
September 24, 1986 (51 FR 33992), it is proposed that spinosad be
classified as Group E for carcinogenicity (no evidence of
carcinogenicity) based on the results of carcinogenicity studies in two
species. There was no evidence of carcinogenicity in an 18-month mouse
feeding study and a 24-month rat feeding study at all dosages tested.
The NOAELs shown in the mouse carcinogenicity study were 11.4 and 13.8
mg/kg/day, respectively for male and female mice. A maximum tolerated
dose was achieved at the top dosage level tested in both of these
studies based on excessive mortality. Thus, the doses tested are
adequate for identifying a cancer risk. Accordingly, a cancer risk
assessment is not needed.
7. Neurotoxicity. In an acute neurotoxicity study, groups of
Fischer 344 rats (10/sex/dose) received a single oral (gavage)
administration of Spinosad (87.9%) at dose levels of 0, 200, 630, or
2,000 mg/kg. There were no effects on neurobehavioral endpoints or
histopathology of the nervous system. For neurotoxicity, the NOAEL was
>2,000 mg/kg (HDT); a LOAEL was not established.
In a subchronic neurotoxicity study, groups of Fischer 344 rats
(10/sex/dose) were administered diets containing Spinosad at levels of
0, 0.003, 0.006, 0.012, or 0.06%(0, 2.2, 4.3, 8.6, or 42.7 mg/kg/day
for males and 2.6, 5.2, 10.4, or 52.1 mg/kg/day for females,
respectively). There were no effects on neurobehavioral endpoints or
histopathology of the nervous system. For neurotoxicity, the NOAEL was
<gr-thn-eq>42.7 for males and <gr-thn-eq>52.1 mg/kg/day for females
(HDT).
In the 2-year chronic toxicity study, groups of Fischer 344 rats
(65/sex/dose) received diets containing Spinosad at dose levels of 0,
0.005, 0.02, 0.05, or 0.1% (0, 2.4, 9.5, 24.1, or 49.4 mg/kg/day for
males and 0, 3.0, 12.0, 30.3, or 62.2 mg/kg/day for females,
respectively). Neurobehavioral testing performed at 3, 6, 9, and 12
months of study was negative, and histopathological evaluation of
perfused tissues at study termination did not identify pathology of the
central or peripheral nervous system. There was no evidence of
neurotoxicity. For neuropathology, the NOAEL was 0.1% (>49.4 mg/kg/day
for males and >62.8 mg/kg/day for females).
8. Metabolism. In rat metabolism of spinosad (technical), no major
differences were found between the bioavailability, routes of
excretion, or metabolism of <SUP>14</SUP>C-XDE-105 (Factor A) and
<SUP>14</SUP>C-XDE-105 (Factor D) in Fischer 344 rats following oral
administration as a suspension of 100 mg/kg bwt. The major elimination
route was fecal excretion for both factors. About 80% (Factor A) and
66% (Factor D) was absorbed with about 20% (Factor A) and 34% (Factor
D) of the dose eliminated unabsorbed in the feces. By 48 hours post-
dosing, >60% (Factor A) & >80% (Factor D) had been recovered in the
urine and the feces. Based on the terminal half-lives for fecal and
urinary excretion, the elimination half-life for Factor A ranged from
25-42 hours and the half-life for Factor D ranged from 29-33 hours. The
tissues and carcass contained very low levels of radioactivity at 168
hours post-dosing, <0.1% of the administered dose/gram tissue.The
primary fecal, urinary, and the biliary metabolites were identified as
the glutathione conjugates of the parent and N- and O-demethylated XDE-
105. The absorption, distribution, metabolism, and elimination of
<SUP>14</SUP>C-XDE-105 were similar for Factors A and D.
The residue of concern for tolerance setting purposes is the parent
material (spinosyn A and spinosyn D). Thus, there is no need to address
metabolite toxicity.
B. Toxicological Endpoints
1. Acute toxicity. EPA did not select a dose and endpoint for an
acute dietary risk assessment due to the lack of toxicological effects
attributable to a single exposure (dose) in studies available in the
data base including oral developmental toxicity studies in rats and
rabbits. In the acute neurotoxicity study the NOAEL was not shown at
2,000 mg/kg/day HDT. A risk assessment is not required as no
appropriate endpoint is available.
2. Short- and intermediate-term toxicity--Short- (1 day to 7 days),
intermediate- (1 week to several months), and chronic-term occupational
and residential dermal and inhalation toxicity). EPA did not select a
dose or
[[Page 28366]]
endpoint for short-, intermediate and long-term dermal risk assessments
because of: (i) Lack of appropriate endpoints; (ii) the combination of
molecular structure and size as well as the lack of dermal or systemic
toxicity at 2,000 mg/kg/day in a 21-day dermal toxicity study in rats
which indicates the lack of dermal absorption; and (iii) the lack of
long-term exposure based on the current use pattern. EPA also
determined that based on the current use pattern and exposure scenario,
an inhalation risk assessment is not required.
3. Chronic toxicity. EPA has established the RfD for spinosad at
0.027 mg/kg/day. This RfD is based on a NOAEL of 2.68 mg/kg/day
established in a chronic toxicity study in dogs. The LOAEL was 8.46 mg/
kg/day based on vacuolation in glandular cells (parathyroid) and
lymphatic tissues, arteritis and increases in serum enzymes such as
alanine aminotransferase, and aspartate aminotransferase, and
triglyceride levels in dogs fed spinosad in the diet at dose levels of
1.44, 2.68, or 8.46 mg/kg/day for 52 weeks. A 100-fold uncertainty
factor (UF) was applied to the NOAEL of 2.68 mg/kg//day to account for
inter- and intra- species variation. The resulting RfD was calculated
to be 0.0268 mg/kg/day.
4. Carcinogenicity. The RfD Committee determined that there is no
evidence of carcinogenicity in studies in either the mouse or rat.
Therefore, a carcinogenic risk assessment is not required.
C. Exposures and Risks
1. From food and feed uses. Tolerances have been established (40
CFR 180.495) for the residues of spinosad, in or on a variety of raw
agricultural commodities. Spinosad is registered for use on a number of
agricultural commodities, including apples, Brassica vegetables, and
fruiting vegetables (excluding cucurbits). Additionally, spinosad is
registered for pest control in turfgrass and ornamental plants.
Application rates range from 0.023 to 0.156 lb a.i./(acre)A, depending
on the target pest and the crop. The maximum seasonal application rate
is 0.45 lb a.i./A. Application intervals range from 7 to 14 days, with
restriction against too many applications per season and/or pest
generation, to avoid resistance. Pre-harvest intervals range from 1 to
14 days. Risk assessments were conducted by EPA to assess dietary
exposures from spinosad as follows:
i. Acute exposure and risk. Acute dietary risk assessments are
performed for a food-use pesticide if a toxicological study has
indicated the possibility of an effect of concern occurring as a result
of a 1-day or single exposure. The Agency did not select a dose and
endpoint for an acute dietary risk assessment due to the lack of
toxicological effects attributable to a single exposure (dose) in
studies available in the data base including oral developmental
toxicity studies in rats and rabbits. In the acute neurotoxicity study,
the NOAEL was <gr-thn-eq>2,000 mg/kg/day.
Acute dietary risk assessments are performed for a food-use
pesticide if a toxicological study has indicated the possibility of an
effect of concern occurring as a result of a 1-day or single exposure.
No acute toxicological endpoints were identified for spinosad due to
the lack of toxicological effects attributable to a single exposure
(dose). Therefore, the Agency concludes that there is a reasonable
certainty of no harm from acute dietary exposure. Acute dietary risk
assessment is not required.
ii. Chronic exposure and risk. In conducting this chronic dietary
risk assessment, EPA has made very conservative assumptions: 100% of
citrus, almonds, apples, fruiting (except cucurbit) vegetables,
Brassica leafy vegetables, leafy vegetables, cottonseed, and ruminant
commodities having spinosad tolerances will contain spinosad residues
and those residues will be at the level of the established tolerance.
Additionally, residues of 0.02 ppm were assumed for all other forms to
support a pending section 18 action on spinosad. This results in an
overestimate of human dietary exposure. Thus, in making a safety
determination for proposed tolerance(s), EPA is taking into account
this conservative exposure assessment.
The existing spinosad tolerances (published, pending, and including
the necessary section 18 tolerances) result in a Theoretical Maximum
Residue Contribution (TMRC) that is equivalent to the following
percentages of the FQPA chronic population adjusted dose (cPAD) for the
following population subgroups: for the U.S. population (48 states) the
TMRC is 0.005658 mg/kg/day which represents 21% of the cPAD, and for
children (1 to 6 years old), the highest exposed subgroup, the TMRC is
0.010522 mg/kg/day utilizing 39% of the cPAD.
2. From drinking water. Monitoring data depicting residue levels of
spinosad in drinking water are not available. Therefore, EPA cannot
perform a quantitative risk assessment for drinking water exposure.
Instead, EPA had used modeled estimated environmental concentrations
(EECs), and back-calculated drinking water levels of comparison
(DWLOCs) to determine whether exposure to spinosad via drinking water
is likely to be of concern.
EPA concludes that the available data on spinosad show that the
compound is not mobile or persistent, and therefore has little
potential to leach to ground water. Spinosad may however contaminate
surface water upon the release of water from flooded fields to the
environment. Additionally, EPA's Metabolism Assessment Review Committee
determined that the spinosyn Factors A and D are not expected to reach
groundwater (2/10/98). In order to assess drinking water exposures, EPA
used the screening models PRZM (pesticide root zone model) and EXAMS
(exposure analysis modeling systems) to generate surface water EECs
associated with application of spinosad to various crops. Modeled
scenarios were selected because they are expected to represent roughly
the upper 90<SUP>th</SUP> percentile for surface water vulnerability,
given the chemical's geographic use range. The Tier 2 chronic surface
water EEC for spinosad is 0.092 <greek-m>g/L and is based on
application of the insecticide to cole crops (0.13 lb a.i./A/
application, 0.45 lb a.i./A/season). The EEC value is over 1,000 times
less than the lowest DWLOC. Based on the studies, the Agency concludes
that drinking water is not expected to be a significant source of
exposure to spinosad.
i. Acute exposure and risk. No acute toxicity endpoints were
determined from testing and the Agency concludes that there is a
reasonable certainty of no harm from acute risk from drinking water. No
acute risk assessment is required.
ii. Chronic exposure and risk. For the most highly exposed
population subgroup, children (1-6 years old), chronic dietary (food
only) exposure occupies 39% of the cPAD. This is a conservative risk
estimate for reasons described above. The chronic lowest DWLOC for the
infants and children subgroup is 170 ppb. The chronic modeling
estimates (EECs) for spinosad residues in surface water are as high as
0.092 ppb from use on Brassica leafy vegetables. The maximum estimated
concentrations of spinosad in surface water are less than EPA's levels
of concern for spinosad in drinking water as a contribution to chronic
aggregate exposure. Therefore, taking into account present uses and
uses proposed in this risk assessment, EPA concludes with reasonable
certainty that residues of spinosad in drinking water (when considered
along with other sources of
[[Page 28367]]
exposure for which the Agency has reliable data) would not result in
unacceptable levels of aggregate human health risk at this time.
3. From non-dietary exposure. No acute dietary, cancer, or short-,
intermediate-, or chronic-term dermal or inhalation endpoints were
identified by the Agency. Spinosad is currently registered on turf
grass, creating a potential for non-dietary oral exposure to children
who ingest grass. To calculate a quantitative dietary risk from a
potential ingestion of grass (in the absence of acute-, short-, or
intermediate-term oral endpoints), EPA would need to default to the
chronic dietary endpoint. This scenario would represent a child eating
grass for > 6 months continuously. Based on the low application rate
for spinosad on turf (0.41 lbs. ai./A.), its non-systemic nature, its
short half life (especially in sunlight), and the rapid incorporation
of spinosad metabolites into the general carbon pool, EPA believes that
residues of spinosad on turf grass after application would be low and
decrease rapidly over time. EPA believes that it is inappropriate to
perform a quantitative dietary risk representing a chronic scenario
from children eating turf grass. Qualitatively, the risk from children
eating turf grass does not exceed the Agency's level of concern.
Another registered product contains spinosad for use on structural
lumber however, the product is injected into drilled holes and then
sealed after treatment. The product can only be applied by commercial
applicators with very minimal potential risk to the public. Due to the
lack of toxicity endpoints (hazard) and minimal contact with the active
ingredient during and after application, exposure to residential
occupants is not expected. The Agency concludes that there is a
reasonable certainty of no harm from non-dietary exposure.
4. Cumulative exposure to substances with common mechanism of
toxicity. Section 408(b)(2)(D)(v) requires that, when considering
whether to establish, modify, or revoke a tolerance, the Agency
consider ``available information'' concerning the cumulative effects of
a particular pesticide's residues and ``other substances that have a
common mechanism of toxicity.''
EPA does not have, at this time, available data to determine
whether spinosad 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,
spinosad 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 spinosad 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 (62 FR 62961, November 26, 1997).
D. Aggregate Risks and Determination of Safety for U.S. Population
1. Acute risk. Because no acute dietary endpoint was determined
from toxicity testing, the Agency concludes that there is a reasonable
certainty of no harm from acute aggregate risk. An acute aggregate risk
assessment is not required.
2. Chronic risk. Using the TMRC exposure assumptions described in
this unit, EPA has concluded that aggregate exposure to spinosad from
food will utilize 21 percent of the cPAD 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 cPAD because the cPAD 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 spinosad in drinking water and from non-dietary, non-occupational
exposure, EPA does not expect the aggregate exposure to exceed 100% of
the cPAD. EPA concludes that there is a reasonable certainty that no
harm will result from aggregate exposure to spinosad residues.
3. Short- and intermediate-term risk. Short- and intermediate-term
aggregate exposure takes into account chronic dietary food and water
(considered to be a background exposure level) plus indoor and outdoor
residential exposure.
No dermal or inhalation endpoints were identified by EPA. Due to
the nature of the non-dietary use, the Agency believes that the use of
spinosad in treating timbers will not result in any exposure through
the oral route. Therefore, the chronic aggregate risk solely is the sum
of food + water.
4. Aggregate cancer risk for U.S. population. The RfD Committee
determined that there is no evidence of carcinogenicity in studies in
either the mouse or rat. Therefore, a carcinogenic 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 spinosad residues.
E. Aggregate Risks and Determination of Safety for Infants and Children
1. Safety factor for infants and children--i. In general. In
assessing the potential for additional sensitivity of infants and
children to residues of spinosad, EPA considered data from
developmental toxicity studies in the rat and rabbit and a 2-generation
reproduction study in the rat. The developmental toxicity studies are
designed to evaluate adverse effects on the developing organism
resulting from maternal pesticide exposure gestation. Reproduction
studies provide information relating to effects from exposure to the
pesticide on the reproductive capability of mating animals and data on
systemic toxicity.
FFDCA section 408 provides that EPA shall apply an additional
tenfold margin of safety for infants and children in the case of
threshold effects to account for pre- and post-natal toxicity and the
completeness of the data base unless EPA determines that a different
margin of safety will be safe for infants and children. Margins of
safety are incorporated into EPA risk assessments either directly
through use of a margin of exposure (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.
ii. Developmental toxicity studies. See unit II.A.-- Toxicological
profile above.
iii. Reproductive toxicity study. See unit II.A.-- Toxicological
profile above.
iv. Pre- and post-natal sensitivity. There was no increased
susceptibility to rats or rabbits following in utero and/or postnatal
exposure to spinosad.
v. Conclusion. The data provided no indication of increased
susceptibility of rats or rabbits to in utero and/or postnatal exposure
to spinosad. In the prenatal developmental toxicity studies in rats and
rabbits and the 2-generation reproduction study in rats, effects in the
offspring were observed only at or below treatment levels which
resulted in evidence of parental toxicity. In addition, all
neurotoxicity studies were
[[Page 28368]]
negative for effects on the central or peripheral nervous system.
EPA determined that the 10X factor to account for enhanced
sensitivity of infants and children (as required by FQPA) should be
removed. The FQPA factor is removed because: (i) The data provided no
indication of increased susceptibility of rats or rabbits to in utero
and/or postnatal exposure to spinosad. In the prenatal developmental
toxicity studies in rats and rabbits and the 2-generation reproduction
study in rats, effects in the offspring were observed only at or below
treatment levels which resulted in evidence of parental toxicity. (ii)
No neurotoxic signs have been observed in any of the standard required
studies conducted. (iii) The toxicology data base is complete and there
are no data gaps. There is a complete toxicity database for spinosad
and exposure data are complete or estimated based on data that
reasonably account for potential exposures.
2. Acute risk. An acute risk assessment is not required because no
acute toxicological endpoints were identified for spinosad. The Agency
concludes that there is a reasonable certainty of no harm to infants
and children from aggregate exposure.
3. Chronic risk. Using the conservative exposure assumptions
described in this unit, EPA has concluded that aggregate exposure to
spinosad from food will utilize 39% of the cPAD for infants and
children. EPA generally has no concern for exposures below 100% of the
cPAD because the cPAD represents the level at or below which daily
aggregate dietary exposure over a lifetime will not pose appreciable
risks to human health.
4. 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 spinosad residues.
G. Endocrine Disruption
EPA is required to develop a screening program to determine whether
certain substances (including all pesticides and inerts) ``may have an
effect in humans that is similar to an effect produced by a naturally
occurring estrogen, or such other endocrine effect...'' The Agency is
currently working with interested stakeholders, including other
government agencies, public interest groups, industry and research
scientists in developing a screening and testing program and a priority
setting scheme to implement this program. Congress has allowed 3 years
from the passage of FQPA (August 3, 1999) to implement this program. At
that time, EPA may require further testing of this active ingredient
and end use products for endocrine disrupter effects.
III. Other Considerations
A. Metabolism In Plants and Animals
EPA has previously concluded that the nature of the spinosad
residue in plants is adequately understood based on metabolism studies
in apples, cabbage, cotton, tomatoes, and turnips. EPA's Metabolism
Assessment Review Committee determined that the residue of concern is
spinosad (a total of spinosyn A and spinosyn D), as noted in the 40 CFR
180.495 entry for cottonseed.
Similarly, EPA has previously concluded that the nature of the
spinosad residue in animals is adequately understood based on
metabolism studies in the goat and hen. Also noted in the 40 CFR
180.495 entry for cottonseed.
Additionally, EPA has reviewed the results of plant metabolism
studies (apples, cabbage, cotton, tomatoes, turnips) and livestock
metabolism studies (goat and hen). The metabolism of spinosad in plants
and animals is adequately understood for the purposes of these
tolerances. Based on structure/activity relationships, EPA concluded
that the spinosad metabolites/fermentation impurities (spinosyns Factor
B, Factor B or D, Factor K, and other related Factors) were of no more
toxicological concern than the two parent compounds (spinosyns Factor A
and Factor D).
EPA focused on the following data/information: the overall low
toxicity of spinosad; the low levels of metabolites/fermentation
impurities present; and that spinosad appears to photodegrade rapidly
and become incorporated into the general carbon pool. EPA concluded
that only 2 parent compounds (spinosyns Factor A and Factor D) need to
be included in the tolerance expression and used for dietary risk
assessment purposes.
B. Analytical Enforcement Methodology
Method GRM 94.02 (method for determination of spinosad residues in
cottonseed and related commodities using HPLC/UV) underwent successful
independent lab validation and EPA lab validation and has been
submitted to FDA for inclusion in PAM II as Method I. Additional
methods have been submitted for other crop matrices leafy vegetables -
GRM 95.17; citrus - GRM 96.09; tree nuts - GRM 96.14; fruiting
vegetables - GRM 95.04; and cotton gin byproducts - GRM 94.02.S1. All
of these methods are essentially similar to GRM 94.02 and have been
submitted to FDA for inclusion in PAM II as letter methods. Method GRM
94.02 is adequate for regulation of the tolerance expression.
Method GRM 95.03.R1 (method for determination of spinosad residues
in ruminant commodities using high performance liquid chromatography/
ultraviolet (HPLC/UV)) underwent successful validation by EPA's lab.
The method was forwarded to FDA for inclusion in PAM II as a Roman
numeral method.
Method RES 95114 (method for determination of spinosad residues in
ruminant commodities using immunoassay) has also successfully passed
validation by EPA's lab. The method was forwarded to FDA for inclusion
in PAM II as a Roman numeral method.
Multi residue Methods (GLN 860.1360) - The results of subjecting
spinosad to FDA Multi residue testing were previously reviewed.
Spinosyns Factor A and D were not recovered from any of the protocols.
The results have been sent to FDA.
Adequate enforcement methodology (example - gas chromotography) is
available to enforce the tolerance expression. The method may be
requested from: Calvin Furlow, PRRIB, IRSD (7502C), Office of Pesticide
Programs, Environmental Protection Agency, 401 M St., SW., Washington,
DC 20460. Office location and telephone number: Rm 101FF, Crystal Mall
#2, 1921 Jefferson Davis Hwy., Arlington, VA, (703) 305-5229.
C. Magnitude of Residues
Magnitude of residue studies were conducted for potatoes at 14
sites. No quantifiable residues were observed in treated field samples
at an application rate of 0.11 pounds active ingredient (lb a.i.) per
acre or at an exaggerated application rate of 0.55 lb a.i. per acre. A
potato processing study is not required because there were no
quantifiable residues in the raw agricultural commodity (RAC) even at
the 5X application rate (5X is the maximum theoretical concentration
factor for potato). Potato is the representative crop for the tuberous
and corm vegetables crop subgroup 1C.
Magnitude of residue studies were conducted for sweet corn at 12
sites, and 5X the label rate. Residues found in these studies ranged
from none detected for sweet corn; 0.09 to 0.57 ppm for corn forage;
and 0.03 to 0.82 ppm for corn fodder.
[[Page 28369]]
A ruminant feeding study was previously accepted by the Agency.
Based on the results of this study, the data support the currently
established tolerances: fat (of cattle, goats, hogs, horses, and sheep)
at 0.6 ppm; meat (of cattle, goats, hogs, horses, and sheep) at 0.04
ppm; meat byproducts (of cattle, goats, hogs, horses, and sheep) at 0.2
ppm; milk fat at 0.5 ppm; and whole milk at 0.04 ppm. These levels are
adequate for the feed items associated with all existing and proposed
uses covered in this risk assessment.
Requirements for a poultry feeding study have been waived based on
the minimal impact of spinosad residues in a typical poultry diet.
D. International Residue Limits
No CODEX, Canadian, or Mexican maximum residue levels (MRLs) have
been established for residues of spinosad on any crops.
IV. Conclusion
Therefore, the time-limited tolerances are established for residues
of spinosad in or on sweet corn at 0.02 ppm, sweet corn forage at 0.6
ppm, sweet corn stover at 1.0 ppm, and a permanent tolerance for
tuberous and corm vegetables (crop subgroup 1C) at 0.02 ppm.
V. Objections and Hearing Requests
The new FFDCA section 408(g) provides essentially the same process
for persons to ``object'' to a tolerance regulation 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 July 26, 1999, 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 under the ``ADDRESSES'' section (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
regulation. The objections submitted must specify the provisions of the
regulation deemed objectionable and the grounds for the objections (40
CFR 178.25). Each objection must be accompanied by the fee prescribed
by 40 CFR 180.33(i). EPA is authorized to waive any fee requirement
``when in the judgement of the Administrator such a waiver or refund is
equitable and not contrary to the purpose of this subsection.'' For
additional information regarding tolerance objection fee waivers,
contact James Tompkins, 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: Rm. 239, Crystal Mall #2, 1921 Jefferson Davis Hwy.,
Arlington, VA, (703) 305-5697, tompkins.jim@epa.gov. Requests for
waiver of tolerance objection fees should be sent to James Hollins,
Information Resources and Services Division (7502C), Office of
Pesticide Programs, Environmental Protection Agency, 401 M St., SW.,
Washington, DC 20460.
If a hearing is requested, the objections must include a statement
of the factual issues on which a hearing is requested, the requestor's
contentions on such issues, and a summary of any evidence relied upon
by the requestor (40 CFR 178.27). A request for a hearing will be
granted if the Administrator determines that the material submitted
shows the following: There is genuine and substantial issue of fact;
there is a reasonable possibility that available evidence identified by
the requestor would, if established, resolve one or more of such issues
in favor of the requestor, taking into account uncontested claims or
facts to the contrary; and resolution of the factual issues in the
manner sought by the requestor would be adequate to justify the action
requested (40 CFR 178.32). Information submitted in connection with an
objection or hearing request may be claimed confidential by marking any
part or all of that information as CBI. Information so marked will not
be disclosed except in accordance with procedures set forth in 40 CFR
part 2. A copy of the information that does not contain CBI must be
submitted for inclusion in the public record. Information not marked
confidential may be disclosed publicly by EPA without prior notice.
VI. Public Record and Electronic Submissions
EPA has established a record for this regulation under docket
control number [OPP-300864] (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.
Objections and hearing requests may be sent by e-mail directly to
EPA at:
opp-docket@epa.gov.
E-mailed objections and hearing requests must be submitted as an
ASCII file avoiding the use of special characters and any form of
encryption.
The official record for this regulation, as well as the public
version, as described in this unit 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 record which
will also include all comments submitted directly in writing. The
official 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 a tolerance under section 408(d) of the
FFDCA 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) (Public Law 104-4). Nor
does it require any prior consultation as specficed 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).
[[Page 28370]]
In addition, since tolerances and exemptions that are established
on the basis of a petition under FFDCA section 408(d), such as the
tolerance in this final rule, do not require the issuance of a proposed
rule, the requirements of the Regulatory Flexibility Act (RFA) (5
U.S.C. 601 et seq.) do not apply. Nevertheless, the Agency 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 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 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 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: May 14, 1999.
Richard P. Keigwin, Jr.,
Acting Director, Registration Division, Office of Pesticide Programs.
Therefore, 40 CFR chapter I is amended as follows:
PART 180--AMENDED
1. The authority citation for part 180 continues to read as
follows:
Authority: 21 U.S.C. 321(q), (346a), and 371.
2. In Sec. 180.495, in paragraph (a), by revising the introductory
text, by adding to the table entries for corn, sweet, forage; corn,
sweet, kernal, plus cob with husk removed; corn, sweet, stover; and
tuberous and corm vegetables (crop subgroup 1C) to read as follows:
Sec. 180.495 Spinosad; tolerances for residues.
(a) * * * Tolerances are established for residues of the
insecticide spinosad in or on the food commodities in the table to this
paragraph. Spinosad is a fermentation product of Saccharopolyspora
spinosa. The product consists of two related active ingredients:
Spinosyn A (Factor A; CAS 131929-60-7) or 2-[(6-deoxy-2,3,4-tri-O-
methyl-<greek-a>-L-manno-pyranosyl)oxy]-13-[[5-(dimethylamino)-
tetrahydro-6-methyl-2H-pyran-2-yl]oxy]-9-ethyl-
2,3,3a,5a,5b,6,9,10,11,12,13,14,16a,16b-tetradecahydro-14-methyl-1H-as-
Indaceno[3,2-d]oxacyclododecin-7,15-dione; and Spinosyn D (Factor D;
CAS 131929-63-0) or 2-[(6-deoxy-2,3,4-tri-O-methyl-<greek-a>-L-manno-
pyranosyl)oxy]-13-[[5-(dimethyl-amino)-tetrahydro-6-methyl-2H-pyran-2-
yl]oxy]-9-ethyl-2,3,3a,5a,5b,6,9,10,11,12,13,14,16a, 16b-
tetradecahydro-4,14-methyl-1H-as-Indaceno[3,2-d]oxacyclododecin-7,15-
dione. Typically, the two factors are present at an 85:15 (A:D) ratio.
------------------------------------------------------------------------
Expiration/
Commodity Parts per Revocation
million date
------------------------------------------------------------------------
* * * * *
Corn, sweet, forage........................... 0.6 06/20/01
Corn, sweet, kernel, plus cob with husk 0.02 06/20/01
removed......................................
Corn, sweet, stover........................... 1.0 06/20/01
* * * * *
Tuberous and corm vegetables (crop subgroup 0.02 None
1C)..........................................
------------------------------------------------------------------------
* * * * *
[FR Doc. 99-12934 Filed 5-25-99; 8:45 am]
BILLING CODE 6560-50-F