EPA REGISTRATION DIVISION COMPANY NOTICE OF FILING FOR 

PESTICIDE PETITIONS PUBLISHED IN THE FEDERAL REGISTER 

EPA Registration Division contact: Laura Nollen, (703) 305-7390

Interregional Research Project Number 4 (IR-4)

Petition # 1E7958

EPA has received a pesticide petition, PP#1E7958 from Interregional Research 

Project Number 4 (IR-4), 500 College Road East, Suite 201 W, Princeton, NJ 08540

proposing, pursuant to section 408(d) of the Federal Food, Drug, and Cosmetic Act 

(FFDCA), 21 U.S.C. 346a(d), to amend 40 CFR part 180.641 by establishing a tolerance 

for residues of spirotetramat (cis-3-(2,5-dimethlyphenyl)-8-methoxy-2-oxo-1-

azaspiro[4.5]dec-3-en-4-yl-ethyl carbonate]) and its metabolites BYI 08330-enol (cis-3-

(2,5-dimethylphenyl)-4-hydroxy-8-methoxy-1-azaspiro[4.5]dec-3-en-2-one), BYI 08330-

ketohydroxy (cis-3-(2,5-dimethylphenyl)-3-hydroxy-8-methoxy-1-azaspiro[4.5]decane2,4-dione), BYI08330-enol-Glc (cis-3-(2,5-dimethylphenyl)-8-methoxy-2-oxo-1-

azaspiro[4.5]dec-3-en-4-yl beta-D-glucopyranoside), and BYI 08330-mono-hydroxy (cis3-(2,5-dimethylphenyl)-4-hydroxy-8-methoxy-1-azaspiro[4.5]decan-2-one), calculated as 

spirotetramat equivalents, in or on the raw agricultural commodities taro, leaves at 9 parts 

per million (ppm); watercress at 1.5 ppm; pomegranate at 0.5 ppm; banana at 4 ppm; 

vegetable, bulb, group 3-07 at 0.6 ppm; berry, low growing, except strawberry, subgroup 

13-07H at 0.3 ppm; bushberry subgroup 13-07B at 3 ppm; artichoke, globe at 2 ppm; 

vegetable, fruiting, group 8-10 at 2.5 ppm; fruit, pome, group 11-10 at 0.7 ppm; fruit, 

citrus, group 10-10 at 0.6 ppm; pineapple at 0.3 ppm; pineapple, process residue at 0.36 

ppm; coffee, green beans at 0.2 ppm; and coffee, roast beans at 0.32 ppm.

Upon approval of the aforementioned tolerances, 40 CFR part 180.641 should be 

amended to remove the following established tolerances as they will be superseded by 

inclusion in updated crop groups or subgroups: Onion, bulb, subgroup 3A-07 at 0.30 

ppm; fruit, citrus, group 10 at 0.60 ppm; fruit, pome, group 11 at 0.70 ppm; okra at 2.5 

ppm; and vegetable, fruiting, group 8 at 2.5 ppm.

EPA has determined that the petition contains data or information regarding the elements 

set forth in section 408 (d)(2) of the FDDCA; however, EPA has not fully evaluated the 

sufficiency of the submitted data at this time or whether the data supports granting of the 

petition. Additional data may be needed before EPA rules on the petition.

A. Residue Chemistry

1. Plant metabolism. The nature of the spirotetramat residues in plants and 

livestock is adequately understood. The plant residues of concern for tolerance 

enforcement are the combined residues of spirotetramat (cis-3-(2,5-dimethlyphenyl)-8-
2

methoxy-2-oxo-1-azaspiro[4.5]dec-3-en-4-yl-ethyl carbonate]) and its metabolites BYI 

08330-enol (cis-3-(2,5-dimethylphenyl)-4-hydroxy-8-methoxy-1-azaspiro[4.5]dec-3-en2-one), BYI 08330-ketohydroxy (cis-3-(2,5-dimethylphenyl)-3-hydroxy-8-methoxy-1-

azaspiro[4.5]decane-2,4-dione), BYI08330-enol-Glc (cis-3-(2,5-dimethylphenyl)-8-

methoxy-2-oxo-1-azaspiro[4.5]dec-3-en-4-yl beta-D-glucopyranoside), and BYI 08330-

mono-hydroxy (cis-3-(2,5-dimethylphenyl)-4-hydroxy-8-methoxy-1-azaspiro[4.5]decan2-one), calculated as spirotetramat equivalents.

2. Analytical method. Spirotetramat residues are quantified in raw agricultural 

commodities by high pressure liquid chromatography/triple stage quadrupole mass 

spectrometry (LC/MS/MS) using the stable isotopically labeled analytes as internal 

standards. The limit of quantification (LOQ) for each analyte was 0.01 ppm for all 

commodities.

3. Magnitude of residues. Residue trials were conducted to support the tolerances 

requested above including the following: 

- Blueberry: A total of 11 field trials were conducted in the USA and Canada. 

Cranberry: A total of 6 field trials were conducted in the USA and Canada. 

- Watercress: A total of 3 field trials were conducted in the USA.

- Coffee: A total of 5 field trials were conducted in the USA.

- Banana: A total of 5 field trials were conducted in the USA.

- Pomegranate: A total of 4 field trials were conducted in the USA.

- Globe Artichoke: A total of 5 field trials were conducted in the USA and Canada. 

- Onion, Dry Bulb: A total of 12 field trials were conducted in the USA and Canada.

- Green Onion: A total of 11 field trials were conducted in Canada.

- Pineapple: A total of 5 field trials were conducted in the USA.

B. Toxicological Profile

1. Acute toxicity. Spirotetramat has a low acute oral (LD50 > 2,000 mg/kg bw; 

Category III), dermal (LD50: > 2,000 mg/kg bw; Category III) and inhalative toxicity

(LC50: > 4.183 mg/L air; Category IV) in male and female rats. Though a Category II 

irritant to the eye, spirotetramat is not a skin irritant (Category IV) but did exhibit, under 

the conditions of the guinea pig maximization test, a skin sensitizing potential.

2. Genotoxicty. Treatment-related increases in tumor incidence were not observed 

in either sex in rats or mice. Spirotetramat was also negative for mutagenicity and

clastogenicity in several standard in vivo and in vitro assays.

3. Reproductive and developmental toxicity. Developmental toxicity in the 

absence of maternal toxicity was not observed in either the rat or rabbit. In the rat, 

decreased body weight and food consumption were observed in dams at the limit dose in 

a developmental toxicity study. Developmental toxicity (reduced fetal weight and 

increased incidences of malformations and skeletal deviations) was also observed at the 
3

limit dose. The NOAEL was established at the next lower dose (140 mg/kg bw/day) in 

both dams and offspring. In the rabbit, developmental toxicity was not Page 18 of 65 

observed up to the highest dose tested (160 mg/kg bw/day). However, maternal toxicity

was observed at ≥40 mg/kg bw/day, including a dose-dependent increase in abortion and 

other clinical signs of systemic toxicity in affected animals.

In addition to testicular histopathology observed following subchronic and chronic 

exposure of male rats to spirotetramat, evidence of male reproductive toxicity was 

provided in the 2-generation reproductive toxicity study. Abnormal sperm cells were 

reported in F1-generation male rats treated with 6000 ppm (419 mg/kg bw/day) 

spirotetramat in the diet, and decreased reproductive performance was also observed in 

one of these males. Similar results were obtained in the 1-generation reproductive 

toxicity range-finding study, in which decreased sperm motility and progression and 

increased abnormal sperm cells in the epididymides were observed in F1 males at ≥6000 

ppm (320 mg/kg bw/day). Development of the sexual organs of offspring (balanopreputial separation, vaginal opening) was unaffected in either study, and no treatmentrelated effects were observed at lower doses.

In an investigative study designed to explore the time of onset of testicular toxicity in 

rats, decreased epididymal sperm counts were observed after 10 days or more of 

treatment with 1000 mg/kg bw/day by gavage. Repeated dosing, therefore, is necessary to 

produce male reproductive toxicity in rats. In a second investigative study, male rats were 

treated by gavage with the enol metabolite of spirotetramat for 21 days at a dose of 800 

mg/kg bw/day. Spermatotoxicity, abnormal sperm, and Sertoli cell vacuolation were 

observed in the testes-epididymides of treated animals. Therefore, male reproductive 

toxicity in rats is likely due to the enol metabolite of spirotetramat.

4. Subchronic toxicity. In the rat, spirotetramat-induced testicular changes were 

characterized by increases in tubular degeneration and decreased testicle weight. Increases in 

abnormal spermatozoa and hypospermia were also identified in the rat epididymis. Unlike the 

rat no effects of any kind emerged in the mouse, which was tested up to the limit dose. 

Nonadverse declines in circulating thyroid hormones were identified exclusively in the dog; 

however, no other thyroid-related changes were noted following subchronic exposure.

5. Chronic toxicity. In the dog prolonged exposure to spirotetramat was characterized by

nonadverse declines in circulating thyroid hormones. Below the highest dose tested, no changes 

in thyroid weight, thyroid pathology, compensating increases in thyrotropin (TSH), or clinical 

observations (e.g., neurological signs) suggestive of thyroid compromise and/or hypothyroidism 

were detected in either sex. In contrast to the dog, the rat showed no signs of thyroid 

involvement; slight increases in liver weight and alveolar macrophage accumulation in the lung, 

characterized the one-year chronic response in the rat.

6. Animal metabolism. The pharmacokinetic behavior of spirotetramat is 

characterized by a rapid and complete absorption and rapid elimination from the plasma 

in rats. Following oral administration, 88% to 98% of the administered dose was excreted 

within 24 hours. The predominant route of excretion was by urine, accounting for 88% 
4

to 95% of the administered dose. Less than 0.2 % of the dose was detected in the body

and the gastro-intestinal tract at 48 hours after the dose. Dose rate and frequency did not 

have any significant effects on the rates of absorption and excretion.

The maximum of plasma concentration was reached for all dose groups within 0.09 to 

2.03 hours after administration. From the maximum, the radioactivity concentrations in 

plasma declined steadily by several orders of magnitude within 48 hours for all dose 

groups. Concentrations of radioactivity detected in tissues and organs at the time of 

sacrifice 48 hours post dose administration were very low and below the limit of 

detection for some organs/tissues.

BYI08330 was completely metabolized by the rat and no parent compound was detected 

in the excreta. The major metabolic reaction was cleavage of the ester group leading to 

the formation of the primary and most predominant metabolite BYI08330-enol (53 – 87 

% of the dose administered). All other identified metabolites could be derived from the 

enol intermediate. The second prominent metabolic transformation was demethylation of 

the 8-methoxy group to BYI08330-desmethyl-enol (5 – 37 % of the dose administered). 

Oxidation of the pyrroline moiety to BYI08330-ketohydroxy and BYI08330-desmethylketohydroxy were detected as minor pathways. Other very minor metabolic 

transformations were conjugation of the enol with glucuronic acid to BYI08330-enol-GA 

and oxidation of the aromatic methyl group of the enol metabolite to BYI08330-enolalcohol.

7. Metabolite toxicology. Acute (oral rat) and genotoxicity (bacterial reverse 

mutation) testing was conducted on four plant metabolites of spirotetramat not identified 

in the rat or identified to a minor degree: BYI 08330-cis-ketohydroxy, BYI 08330-

desmethyl-ketohydroxy, BYI 08330-desmethyl-di-hydroxy, and BYI 08330-monohydroxy. With all four metabolites, the results were equivalent to that observed with the 

parent compound (LD50 > 2000 mg/kg; negative = no evidence of mutagenicity)

8. Endocrine disruption. Evidence of thyroid- and testicular-related changes 

emerged in the dog and rat, respectively, following exposure to spirotetramat. During 

both the 90-day and 1-year feeding studies, decreases in circulating T3 and T4 were 

observed exclusively in the dog. Ultimately, based on the total response of the animals to 

the thyroid profile that emerged in both the 90-day and 1-year dog studies, the changes in 

circulating thyroid hormones in the dog were judged to be nonadverse. No thyroid 

effects of any form were observed in either the rat or the mouse. Though effects on 

sperm development in the testes of the rat were identified, there were no data to suggest 

the effect was mediated through some form of spirotetramat-induced hormonal 

interference

C. Aggregate Exposure

1. Dietary exposure. Assessments were conducted to evaluate potential risks due 

to acute and chronic dietary exposure of the U.S. population and selected population 

subgroups to residues of spirotetramat. These analyses included the proposed use of 

spirotetramat on bulb vegetables (Crop Group 3), bushberries and low growing berries 
5

(Crop Group 13B and 13H), artichoke, banana, coffee, pineapple, pomegranate, and 

watercress. Potential exposure from drinking water is also included in these assessments. 

Potential concentrations of spirotetramat residues in drinking water were determined by

Bayer CropScience using the Provisional Cranberry Model. These conservative surface 

water estimates were added to the potential exposure from food. Dietary exposure was 

determined using the CARES Version 3.0 software which uses the food consumption 

data from the 1994-1996, 1998 USDA Continuing Surveys of Food Intake by Individuals.

Acute exposure estimates for spirotetramat were based on an acute reference dose (aRfD) 

of 1.0 mg/kg body weight/day. This aRfD was based on a no observed adverse effect 

level (NOAEL) of 100 mg/kg body weight/day from an acute oral neurotoxicity

screening study with technical grade spirotetramat in rats, applying an uncertainty factor 

of 100 to account for interspecies extrapolation (10X) and intraspecies variation (10X). 

No additional FQPA safety factor was applied; therefore, the aRfD and the acute 

population adjusted dose (aPAD) are the same. 

Chronic exposure estimates for spirotetramat were based on a chronic reference dose 

(cRfD) of 0.05 mg/kg body weight/day. This cRfD is based on a no observed adverse 

effect level (NOAEL) of 5 mg/kg body weight/day from the chronic dog toxicity study

for spirotetramat, applying an uncertainty factor of 100 to account for interspecies 

extrapolation (10X) and intraspecies variation (10X). No additional FQPA safety factor 

was applied; therefore, the cRfD and the chronic population adjusted dose (cPAD) are the 

same.

i. Food and Drinking Water. Acute and chronic dietary assessments were 

conducted based on residue data from GLP field trials and processing studies. The 

assessments included both food and drinking water. For the acute assessment, the entire 

distribution of field trial residues was used for non-blended and partially blended food 

commodities and for blended commodities the average value was used. For the chronic 

assessment, the average residue value was used. Anticipated secondary residues in 

livestock tissues were determined based the Maximum Reasonably Balanced Diets 

(MRBD) approach. The MRBD is constructed from spirotetramat treated feedstuffs and 

then adjusting to feed ratio derived from cattle feed study. 

The Tier 3 acute assessment determined acute dietary exposure to spirotetramat residues 

(food and water) for the U.S. Population and selected population subgroups. The most 

highly exposed population subgroup was infants with an acute exposure at the 99.9th

percentile of 5% of the acute RfD/acute PAD. For the overall U.S. Population the acute 

exposure at the 99.9th percentile was about 2% of the acute RfD/acute PAD. These values 

include exposure from both food and water since potential water exposure was added to 

the potential food exposure in CARES software.

The Tier 3 chronic assessment determined chronic dietary exposure to spirotetramat 

residues (food and water) for the U.S. Population and selected population subgroups. The 

most highly exposed population subgroup was infants with a chronic exposure at the 

99.9thpercentile of about 9% of the chronic RfD/chronic PAD. For the overall U.S. 
6

Population the chronic exposure at the 99.9th percentile was less than 4% of the chronic 

RfD/chronic PAD. These values include exposure from food and water since potential 

water exposure was added to the potential food exposure in the CARES software.

ii. Drinking water. Potential exposure to spirotetramat residues from drinking 

water was included in the above assessment but contributed very little to overall 

exposure. Therefore, exposure from both food and water are included in the above values.

2. Non-dietary exposure. There are currently no registered residential uses of 

spirotetramat. Therefore, a non-dietary residential exposure assessment was not required.

D. Cumulative Effects

Spirotetramat is a ketoenol tetramic acid insecticide. At this time, the EPA has not 

made a determination that spirotetramat and other substances that may have a common 

mechanism of toxicity would have cumulative effects. Therefore, for these tolerance 

petitions, it is assumed that spirotetramat does not have a common mechanism of toxicity

with other substances and only the potential risks of spirotetramat in its aggregate 

exposure are considered. 

E. Safety Determination

1. U.S. population. Using the conservative exposure assumptions described above 

and based on the completeness of the toxicity data, it can be concluded that aggregate 

exposure to residues of spirotetramat present a reasonable certainty of no harm. 

Exposure from residues in crops utilizes about 2% of the aPAD and less than 4% of the

cPAD. These values include potential exposure from both food and drinking water. EPA 

generally has no concerns for exposures below 100% of the Population Adjusted Doses. 

Therefore, the aggregate assessment for all proposed uses for spirotetramat demonstrates 

that there is a reasonable certainty that no harm will result to the US Population from the 

use of spirotetramat. 

2. Infants and children. The developmental and reproductive toxicity of 

spirotetramat was evaluated in developmental toxicity studies in the rat and rabbit and a 

2-generation reproduction study in the rat. These studies are discussed under Section B 

(Toxicology Profile) above. The developmental toxicity data demonstrated no increased 

sensitivity of rats or rabbits to in utero exposure to spirotetramat. In addition, the 

multi-generation reproductive toxicity study did not identify any increased sensitivity of 

rats to in utero or post-natal exposure. Non-maternal toxicity was identified at equivalent 

or higher doses than maternal toxicity in both the rat and the rabbit. The developmental 

toxicity studies are designed to evaluate adverse effects on the developing organism 

resulting from maternal pesticide exposure during gestation. Reproduction studies 

provide information relating to effects from exposure to the pesticide on the reproductive 

capability of mating animals and data on systemic toxicity.

FFDCA section 408 provides that EPA shall apply an additional tenfold margin of safety
7

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. The spirotetramat database is 

complete for FQPA purposes and there are no residual uncertainties for pre-/post-natal 

toxicity for spirotetramat. Therefore, the Special FQPA Safety Factor can be reduced to 

1x. 

Based on the exposure assessments described above and on the completeness and 

reliability of the toxicity data, it can be concluded that the dietary exposure from all 

proposed uses of spirotetramat consumes less than 5% of the aRfD/aPAD at the 99.9th

percentile and less than 9% of the cRfD/cPAD for the most sensitive population 

subgroup. Thus, it can be concluded that there is a reasonable certainty that no harm will 

result from aggregate exposure to spirotetramat residues.

F. International Tolerances

There are currently no CODEX tolerances for spirotetramat.