UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

OFFICE OF 

PREVENTION, PESTICIDES AND 

TOXIC SUBSTANCES 

PC Code 3 9220 1 

DP Barcode D345278 

MEMORANDUM 

DATE: May 30,2008 

SUBJECT: Environmental Fate and Ecological Risk Assessment for the Section 3 

Registration of the New Chemical Spirotetramat 

FROM: Jose Luis Melendez, Chemist 

Michael Hoffmann, Biologist w- (p /Yic 

Environmental Risk Branch V 

Environmental Fate and Effects Division (7507P) 

THROUGH: Mah T. Shamim, Ph.D., Chief 

Environmental Risk Branch V 

Environmental Fate and Effects ~i%sion (7507P) 

TO: Rita Kurnar, Risk Manager Reviewer 

Venus Eagle, Review Manager #0 1 

Meredith Laws, Chief 

Insecticide-Rodenticide Branch 

Registration Division (7505P) 

The attached document contains the Environmental Fate and Effects Division's (EFED) 

screening-level environmental risk assessment for the new chemical Spirotetramat. The risk 

assessment has been conducted in accordance with the Agency guidance on ecological risk 

assessment and the OPP ecological risk assessment Overview document. The proposed 

agricultural uses include citrus fruits (Crop Group 1 O), grapes and small fruit climbing (except 

kiwifruit), pome fruits (Crop Group 1 I), stone hits (Crop Group 12), tree nuts (Crop Group 14 

plus pistachio), hops, Christmas trees, cucurbit vegetables (Crop Group 9), fruiting vegetables 

(Crop Group 8 plus okra), leafy vegetables (Crop Group 4), brassica (Cole) leafy vegetables (Crop 

Group 5), and potatoes and other tuberous and corm vegetables (Crop Subgroup 1C). An 

evaluation of environmental risk to aquatic and terrestrial organisms as a result of the proposed 

uses of the new chemical spirotetramat is summarized in the Executive Summary and the Risk 

Characterization sections of the attached Section 3. 

TEXT SEARCHABLE DOCUMENT
Data Ga~s and Uncertainties 

Environmental Fate Data Gaps: 

A summary of the environmental fate data requirements is provided in Table 1 of this memo. 

The EFED is utilizing the review prepared by the Austrian Agency for Health and Food Safety 

(AGES) for spirotetramat (as stated in Volume 3, Annex B.9: Fate and behaviour in the 

environment). The environmental fate database for the chemical is substantially complete and 

consists mostly of acceptable studies. The database is sufficient to conduct a Tier 1 Risk 

Assessment of the new Terrestrial Food and Non-Food uses of spirotetramat. 

The available soil photodegradation study, provides only limited supplemental information and is 

uncertain because the parent in the dark control samples degraded faster than in the light exposed 

samples. However, from the study, the degradates dimethyl-benzoic acid (21.8% of the applied 

radioactivity or AR at 7 days, also observed in the aerobic outdoors study at 3.3% of the AR) and 

methoxycyclohexanone (10.0% of AR at 2 days, also observed in the aqueous photolysis study 

conducted with sterile natural water at 17.5% of AR) were identified only in the light exposed 

samples, in addition to other transformation products identified in other biodegradation studies 

(e.g., spirotetramat-en01 and spirotetramat-ketohydroxy). The amount of such degradates and the 

rate of soil photodegradation on soil are uncertain. In order to obtain an adequate description of 

the role of soil photodegradation on the environmental fate of spirotetramat, and the presence and 

quantities of degradation1 transformation products, a new photodegradation on soil study, 

conducted on a sterile soil is required. 

There is uncertainty with one of the five soils used in the batch equilibrium study performed in 

the parent spirotetramat for which the taxonomic classification is unknown. The registrant 

provided "Orthic dark brown" as the soil taxonomic classification for the soil (not a soil 

taxonomic classification). Due to the sampling location, it is believed to be of the suborder 

Mollisols. This part of the study is considered supplemental. To upgrade the mobility study to 

acceptable, the EPA is requiring that the registrant provide the soil taxonomy for the 'Saskatoon' 

loam soil (from Saskatchewan, Canada). 

There is uncertainty related to the high levels of non-extracted residues observed very early on in 

the aerobic soil metabolism studies conducted with spirotetramat (22-35% of AR) and 

spirotetrarnat-enol(40-60% of AR). Non-extracted residues were high in other studies as well. 

The registrant indicated that these residues were immobile, but did not provide evidence to prove 

their contention. It is unknown if these residues are bioavailable. For the purpose of calculation 

of the half-life of the total residues of concern (parent, spirotetramat-en01 and spirotetramatketohydroxy), the non-extracted residues were added as if they were persistent compounds. 

Environmental Fate Uncertainties: 

The presence and quantities of aqueous photolysates of sterile buffer solution in the environment 

are uncertain, compared to the presence of aqueous photolysates in natural water. In sterile buffer 

solution (pH 5), the four major transformation products were spirotetramat-photo-cyclopentyl, 

spirotetrarnat-photo-methyl, spirotetramat-photo-formyl and spirotetramat-photo-methyl at 

maxima of 1 1.5% to 42.9% of the applied radioactivity (AR). These are the result of 

rearrangement of the parent. These transformation products were not observed in the photolysis 

study conducted with sterile natural water. 

Spirotetramat-enol's pKa is 5.2, which suggests that it may be ionizable at environmentally 

relevant pH's; however, the DTS03s for spirotetramat-en01 did not appear to depend on the soil 

pH's in aerobic soil metabolism studies conducted in four soils. Nonetheless, the ionization 

potential of spirotetramat-en01 could affect the mobility of the chemical with the soil pH (at high 
pH's high concentrations of the "enolate" form of the chemical would occur and higher mobility 

is expected). In the soil column leaching studies, the range of pH's was 6.1-6.5 for three EU soils 

and it was 5.4 for the FL SL (as measured in CaClz solution); all the derived Kd's were within a 

relatively thin range (0.52-0.86) and the Koc's did not appear to follow a pattern with the pH's. 

The available Koc's for spirotetramat-en01 were estimated horn a series of soil column leaching 

studies instead of the conventional batch equilibrium study. There is uncertainty in those values 

since the chemical is labile under various metabolism conditions; furthermore, it was found that 

spirotetramat-en01 is too labile to withstand a batch equilibrium study (even with sterile soils). 

Spirotetramat-en01 dimers 1 and 2, at up to 5.0 and 7.0% of AR, respectively in the soil 

metabolism studies, were 51.5% of AR in the aerobic outdoors study and <0.2% in the field. It is 

speculated that this may be due to the "hot spots" application method used for spirotetramat in 

aerobic soil metabolism studies. In the "hot spots" application method, utilized in the laboratory 

studies, spirotetramat was applied in acetonitrile at relatively high concentrations. It is argued 

due to the type of application, spirotetramat may have been concentrated in small regions or 

sectors (referred to as "hot spots") in/ on the soil, causing an increased formation of the dimers. 

For the tests conducted with spirotetramat-en01 (with higher solubility, it was applied dissolved in 

water and, hence, at lower concentrations) and in the aerobic outdoors study and in the field (with 

broadcast application of the formulated product, oil dispersion), the levels of the dimers were 

lower. 

Ecological Effects Data Gaps and Uncertainties: 

A summary of the ecological data available for spirotetramat is provided in Table 2 of this 

memo. In agreement with international governmental partners associated with registration efforts 

for this pesticide, ecological effects data evaluation and approval responsibilities are being met 

through the efforts of the Austrian Agency for Health and Food Safety (AGES). The Agency is 

using the results of the AGES review as they appear in Volume 3, Annex B.9: Ecotoxicology 

monograph for registration in Europe. AGES found that the ecological effects database was 

largely complete and that all studies were acceptable for risk assessment purposes. However, a 

few additional data needs have been identified by EFED as described below. 

OPPTS Guideline 850.2300; Avian Reproduction Study with the Mallard Duck (Anas 

platyrh.vnchos): 

A definitive NOAEC based on the available avian reproduction studies has not been established 

for spirotetramat; adverse reproductive effects were observed at the lowest tested concentration in 

the available avian reproduction study with mallards. The most sensitive NOAEC value of <28.8 

mglkg-diet with which chronic avian RQs were calculated, was based on a statistically significant 

-6.58% reduction in mean hatchling bodyweight. Although no additional statistically significant 

effects were observed at this test level, large reductions in other hank effects that were observed 

at 28.8 mglkg-diet included reductions in # of 14-day survivors (122%), # of viable 14-day 

embryos (1 18%), # of live embryos (118%), and # of eggs hatched (122%). Due to the degree of 

these reductions, it is hard to indicate that these effects are not biologically significant and are 

considered meaninsful. Thus, because of the extent of these observed effects, it is reasonable to 

assume they are significant biologically. Therefore, the ability of this study to statistically detect 

what could be considered to be biologically relevant endpoints appears to be limited, and an 

additional study is needed to reduce uncertainty by establishing a definitive NOAEC capable of 

capturing biologically relevant reductions in endpoints. 

OPPTS Guideline 850.3040; Field Testing; for Pollinators 
Despite that the intrinsic hazard potential to bees based on the acute oral and contact studies with 

honey bees appears to be low, brood feeding tests with bees and acute toxicity contact studies 

with other non-target insects (e.g. parasitoid wasps and predatory mites) conducted at less than 

the maximum application rate suggest there is potential for mortality in adults and pupae, massive 

perturbation of brood development, and early brood termination as a result of spirotetramat use. 

This information, coupled with the fact that two other chemicals representing the ketoenole class 

of compounds (spiromesifen and spirodiclofen) have also demonstrated the potential for chronic 

effects on bee broods and development while displaying low acute toxicity, suggests that the 

mode of action of these compounds (i.e., inhibition of lipid biosynthesis) may adversely affect 

bee broods and development. Although a study has been submitted for spirotetramat under 

guideline 850.3040, it was conducted at application rates approximately half of the labelrecommended rates and it was not designed in such a manner that adverse effects resulting from 

treatment could be statistically determined. Therefore, it is recommended that a study design be 

developed in collaboration with the Environmental Fate and Effects Division. 

OPPTS Guideline 850.1075; Freshwater Fish Toxicitv with Fathead Minnows (Pimeohales 

promelas): Under part 158 of Title 40 in the U.S. Code of Federal Regulations for t&e 

registration of conventional pesticide products, it is stated that if the species used in a single fish 

early-life stage toxicity test is different from the two species used for the freshwater fish acute 

toxicity tests, an additional 9Chour LCs0 on the species tested in the early-life stage study must 

be submitted. These conditions apply to spirotetramat and an additional study is requested to fill 

this data gap. These data would help to reduce the uncertainty associated with chronic risk 

estimates for freshwater fish. 

OPPTS Guideline 850.2100; Avian Oral Toxicitv Study with a Passerine Species: 

Under part 158 of Title 40 in the U.S. Code of Federal Regulations for the registration of 

conventional pesticide products, it is stated that data are required on one passerine species in 

addition to either one waterfowl species or one upland game bird species for terrestrial, aquatic, 

forestry, and residential outdoor uses. Currently there are no acute oral toxicity studies with 

passerine species available for spirotetramat. These data would be helpful for characterizing 

interspecies sensitivity, and testing of a passerine addresses concerns that broad, untested avian 

taxa may be more sensitive than previously required mallards and bobwhites. 

EFED Label Recommendations 

Manufacturing Use Product: 

This pesticide is toxic to aquatic invertebrates and oysters. Do not discharge effluent containing 

this product into lakes, streams, ponds, estuaries, oceans, or other waters unless in accordance 

with the requirements of a National Pollutant Discharge Elimination System (NPDES) permit and 

the permitting authority has been notified in writing prior to discharge. Do not discharge effluent 

containing this product to sewer systems without previously notifying the local sewage treatment 

plant authority. For guidance contact your State Water Board or Regional Office of the EPA. 

This chemical has properties and characteristics associated with chemicals detected in ground 

water. The use of this chemical in areas where soils are permeable, particularly where the water 

table is shallow, may result in ground-water contamination. 

End-Use Product: 

This product is potentially toxic to honey bee larvae through residues in pollen and nectar, but not 

to adult honey bees. Exposure of adult bees to direct treatment or residues on blooming crops can 

lead to effects on honey bee larvae. See the "Directions for Use" section of this label for specific 

crop application instructions that minimize risk to honey bee larvae. 
This pesticide is toxic to aquatic invertebrates and oysters. Do not apply directly to water, to areas 

where surface water is present, or to intertidal areas below the mean high water mark. This 

product may contaminate water through drift of spray in wind. Do not apply when weather 

conditions favor drift from treated areas. Drift and runoff from treated areas may be hazardous to 

aquatic organisms in neighboring areas. Do not contaminate water when disposing of equipment 

washwaters or rinsate. 

This product has a high potential for runoff for several weeks after application. Poorly draining 

soils and soils with shallow water tables are more prone to produce runoff that contains this 

product. A level, well maintained vegetative buffer strip between areas to which this product is 

applied and surface water features such as ponds, streams, and springs will reduce the potential 

for contamination of water from rainfall-runoff. Runoff of this product will be reduced by 

avoiding applications when rainfall is forecasted to occur within 48 hours. 

Observe all cautions and limitations on labeling of all products used in mixtures. 

Peer Reviewers 

This chapter was peer-reviewed by Michael Barrett, Ph.D., Chemist, and Nicholas Federoff, 

Biologist. 
Acute Mammalian Ora 

835.6100 

835.6200 

835.6300 

850.1730 

*An additional study with no MRID; **Waived based on low vapor pressure and Henry's law constant; ***Waived based on low 

octanoW water partition coefficient 

1. A new study is required. 2. Additional data should be submitted to upgrade the study. 

Terrestrial Field Dissipation 

Aquatic Field Dissipation 

Forestry Dissipation 

Accumulation in Fish 

46904421, 

46904422, 

46904423, 

46904424, 

46904417 

No Data 

No Data 

No Data 

Acceptable 

NIA 

NIA 

Waived*** 

no 

no 

no 

no 
Midge 48-hour Acute 

No data submitted 

No data submitted 

No data submitted 

No data submitted 
No data submitted 

144-1 

850.3020 

141-2 

850.3030 

850.6200 

Non-guideline 

Non-guideline 

Non-guideline 

Acute Honeybee 

Contact and Oral 

Toxicity Test 

Residues on Foliage 

Honey Bee Toxicity 

Test 

Earthworm Sub-chronic 

Toxicity 

Earthworm Acute 

Toxicity 

Earthworm Crowth and 

Reproductive Toxicity 

48-hour Contact of 

Parasitoid Wasps with 

Dried Residues on 

Treated Glass Plates 

7-day Contact of 

Predatory Mite with 

TGAI 

TEP (SC 240) 

TEP (OD 150) 

46904449 

46904469 

46904461 

No 

No 

No 

No 

No 

No 

No 

No data submitted 

Spirotetrarnat-4-methoxy-cyclohexanone 

TGAI 

Spirotetramat-ketohydroxy 

Spirotetramat-en01 

TEP (OD 150) 

TEP (OD 150) 

473?9101 

46904455 

46904472 

Moser & 

Scheffczyk, 2005 

Waltersdorfer, 

2005a 

Waltersdorfer, 

2005b 
850.3040 

Non-guideline 

Non-guideline 

Standard study classifications (i.e., Acceptable, Supplemental, Invalid) were not assigned because ecological effects data evaluation and 

approval responsibilities are being met through the efforts of the Austrian Agency for Health and Food Safety (AGES). The Agency is using 

the results of the AGES review as they appear in Volume 3, Annex B.9: Ecotoxicology monograph for registration in Europe. AGES found that 

the ecological effects database was largely complete and that all studies were accepfable for risk assessment purposes. However, a few 

additional data needs have been identified by EFED as described above. 

Field Test for 

Pollinators 

Honey Bee Feeding 

Test 

Honey Bee Semi-Field 

Test 

Summary of the 

Evaluation of Bee 

Brood Effects in Tunnel 

Trial 

TEP (OD 150) 

TEP (OD 100) 

TEP (SC 240) 

TEP (OD 100) 

TEP (SC 240) 

TEP (OD 150) 

46904462 

46904458 

46904470 

46904459 

47276901 

Yes 

No 

No 

No