Annex B 

Spirotetramat 

B.8 Fate and behaviour in the environment

Reviewed by: 

AGES, Austria 

Peer – reviewed by: 

US-EPA, USA 

PMRA, Canada 
– 2 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Contents: 

B.8 Fate and behaviour in the environment................................................................................5

B.8.1 Route and rate of degradation in soil .................................................................................10

B.8.1.1 Route of degradation (OECD Annex IIA, 7.1) .....................................................................10

B.8.1.1.1 Aerobic degradation in soil (OECD Annex IIA, 7.1.1).............................................................10

B.8.1.1.2 Anaerobic degradation in soil (OECD Annex IIA, 7.1.2).........................................................36

B.8.1.1.3 Soil photolysis (OECD Annex IIA, 7.1.3) ................................................................................42

B.8.1.1.4 Summary on route of degradation in soil (laboratory) ............................................................50

B.8.1.2 Rate of degradation in soil (OECD Annex IIA, 7.2, IIIA, 9.1) .............................................54

B.8.1.2.1 Aerobic degradation rate of the active substance at 20 °C (OECD Annex IIA, 7.2.1, 

IIIA, 9.1.1) ...............................................................................................................................54

B.8.1.2.2 Aerobic degradation of the active substance at 10 °C (OECD Annex IIA, 7.2.2)...................58

B.8.1.2.3 Aerobic degradation of relevant metabolites at 20 °C (OECD Annex IIA, 7.2.3) ...................59

B.8.1.2.4 Anaerobic degradation rate of the active substance (OECD Annex IIA, 7.2.4, IIIA, 

9.1.2).......................................................................................................................................73

B.8.1.2.5 Anaerobic degradation rate of relevant metabolites (OECD Annex IIA, 7.2.5) ......................73

B.8.1.2.6 Summary on the rate of degradation in laboratory soil studies ..............................................74

B.8.1.3 Field studies (OECD Annex IIA, 7.3, IIIA, 9.2).....................................................................79

B.8.1.3.1 Soil dissipation testing (OECD Annex IIA, 7.3.1, IIIA, 9.2.1) ..................................................79

B.8.1.3.2 Soil residue testing................................................................................................................102

B.8.1.3.3 Soil accumulation testing on relevant soils...........................................................................102

B.8.1.3.4 Supplemental studies ...........................................................................................................102

B.8.1.3.5 Summary on field dissipation studies ...................................................................................115

B.8.2 Adsorption, desorption and mobility in soil ....................................................................118

B.8.2.1 Mobility studies (OECD Annex IIA, 7.4, IIIA, 9.3) .............................................................118

B.8.2.1.1 Adsorption and desorption of the active substance (OECD Annex IIA, 7.4.1) .....................118

B.8.2.1.2 Adsorption and desorption of relevant metabolites, degradation and reaction products 

(OECD Annex IIA, 7.4.2) ......................................................................................................123

B.8.2.1.3 Column leaching studies with the active substance (OECD Annex IIA, 7.4.3, IIIA, 

9.3.1).....................................................................................................................................139

B.8.2.1.4 Column leaching studies with relevant metabolites (OECD Annex IIA, 7.4.4, IIIA, 9.3.1)....139

B.8.2.1.5 Aged residue column leaching studies (OECD Annex IIA, 7.4.5) ........................................150

B.8.2.1.6 Leaching (TLC) (OECD Annex IIA, 7.4.6) ............................................................................150

B.8.2.1.7 Lysimeter studies (OECD Annex IIA, 7.4.7, Annex IIIA, 9.3.2) ............................................150

B.8.2.1.8 Field leaching studies (OECD Annex IIA, 7.4.8, Annex IIIA, 9.3.3)......................................150

B.8.2.1.9 Volatility laboratory and field study (OECD Annex IIA, 7.4.9, IIIA, 9.3.4, 9.3.5)...................150

B.8.2.1.10 Summary on the mobility in soil ............................................................................................151

B.8.3 Predicted environmental concentration in soil (PECS) (OECD Annex IIIA, 9.4, 9.5) ....154

B.8.4 Fate and behaviour in the water........................................................................................155

B.8.4.1 Hydrolytic degradation (OECD Annex IIA, 7.5) ................................................................155
– 3 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

B.8.4.2 Photolytic degradation (OECD Annex IIA, 7.6) ................................................................160

B.8.4.3 Ready biodegradability of the active substance (OECD Annex IIA, 7.7).......................171

B.8.4.4 Degradation in aquatic systems (OECD Annex IIA, 7.8).................................................172

B.8.4.4.1 Aerobic biodegradation in aquatic systems (OECD Annex IIA, 7.8.1) .................................172

B.8.4.4.2 Anaerobic biodegradation in aquatic systems (OECD Annex IIA, 7.8.2) .............................172

B.8.4.4.3 Water/sediment studies (OECD Annex IIA, 7.8.3)................................................................172

B.8.4.4.4 Supplemental studies ...........................................................................................................181

B.8.4.4.5 Summary on fate & behaviour in aquatic systems ...............................................................183

B.8.4.5 Degradation in the saturated zone (OECD Annex IIA, 7.9) .............................................188

B.8.5 Impact on water treatment procedures (OECD Annex IIIA, 9.6.4)..................................189

B.8.6 Predicted environmental concentration in ground water for the active substance 

and metabolites (PECGW) (OECD Annex AIII, 9.6)............................................................190

B.8.7 Predicted environmental concentration in surface water and sediment for the 

active substance and metabolites (PECSW, PECSED) (OECD Annex AIII, 9.7, 9.8).........190

B.8.8 Fate and behaviour in the air.............................................................................................191

B.8.8.1 Rate and route of degradation in air (OECD Annex IIA, 7.10, IIIA, 9.9)...............................191

B.8.9 Predicted environmental concentration in the air (PECA) ..............................................193

B.8.10 Definition of the residues (OECD Annex IIA, 7.11)..........................................................194

B.8.11 Monitoring data (OECD Annex IIA, 7.12) ..........................................................................194

B.8.12 Other/special studies (OECD Annex IIA, 7.13, AIII 9.10) .................................................194

B.8.13 References relied on ..........................................................................................................201

Appendix: 

B.8.3 Predicted environmental concentration in soil (PECS) for the active substance 

and relevant metabolites (OECD Annex IIIA, 9.4, 9.5).....................................................210

B.8.6 Predicted environmental concentration in groundwater (PECGW) for the active 

substance and relevant metabolites (OECD Annex IIIA, 9.6) .........................................214

B.8.7 Predicted environmental concentration in surface water (PECSW) and sediment 

(PECSED) for the active substance and relevant metabolites (OECD Annex IIIA, 

9.7, 9.8).................................................................................................................................220

B.8.9 Predicted environmental concentration in the air (PECA) (OECD Annex IIIA, 9.9).......226
– 4 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Abbreviations used in the DAR: 

AR applied radioactivity 

ASE accelerated solvent extraction 

BBCH Biologische Bundesanstalt, Bundessortenamt and Chemical Industry 

CH crop height 

DAT days after treatment 

DFOP double first order in parallel 

DM dry mass 

ESI electro spray ionisation 

EU European Union 

FOCUS Forum for co-ordination of pesticide fate models and their use 

FOMC first order multi compartment (Gustafson-Holden) 

GAP good agricultural practice 

HAT hours after treatment 

HPLC high pressure liquid chromatography 

HS Hockey-Stick 

LC liquid chromatography 

LOD limit of detection 

LOQ limit of quantification 

LSC liquid scintillation counting 

MC moisture content 

MS mass spectroscopy 

MWHC maximum water holding capacity 

NER non-extractable residues 

NMR nuclear magnetic resonance 

OD oil dispersion 

RAD radioactivity detector 

ROI region of interest 

RP reversed phase 

SFO single first order 

SFO-RB single first order reversible binding 

TLC thin layer chromatography 

TRR total recovered residues 

UV ultraviolet 

WHC water holding capacity 
– 5 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

B.8 Fate and behaviour in the environment 

Spirotetramat is a new systemic broad spectrum insecticide intended for the control of sucking pests. 

Spirotetramat belongs to the chemical class of tetramic acid derivates (ketoenoles). 

Representative formulation 

The product OD 150 is formulated as an oil dispersion containing 150 g spirotetramat L-1 and is used as 

systemic broad spectrum insecticide against sucking pests. The maximum total application rate in a season 

is 288 g ai ha-1. The intended EU use patterns are described in Table B.8-1. 

Table B.8-1: Intended uses of spirotetramat as formulation OD 150. 

Culture Use 

Number 

of applications 

Interval 

[d] 

Application 

timing 

BBCH 

code 

Crop interception 

[%] 

Application rate 

[kg ai ha-1] 

Lettuce, 

head and leafy F

a

 Max. 2 14 BBCH 48 at last 

application 48 70 0.072 

Lettuce, 

head and leafy G

b

 Max. 2 14 BBCH 48 at last 

application 48 70 0.072 

Citrus, all types F 2 21 BBCH 78 at last 

application 78 70 

0.096 m-1 CHc

, 

max. 0.288 

(max. CH = 3 m) 

a

 F denotes field use 

b

 G denotes glasshouse use 

c

 CH denotes crop height 

Isomerism of the parent substance 

Two stereo isomers of spirotetramat, cis- and trans-isomer, are possible. The cis-isomer is the active

substance, the trans-isomer (AE 1302942) is declared as an isomeric impurity in a maximum content of 

1.5 % (15 g kg-1). The cis/trans isomers ratio is about 98/2. 

Labelling of the parent substance used for environmental fate studies 

In environmental fate studies spirotetramat was conducted using one or two labelling positions (Table B.8-2) 

as well as the non-labelled parent compound. 

Table B.8-2: Labels of spirotetramat used in the environmental studies. 

Applicants name 

Abbreviation 

used in the 

DAR 

Structure Mass 

[g mol-1] Chemical name 

Azaspirodecenyl-3-14C [3-14C] NH

O

O

O O

CH3

CH3

H3C

H

O

CH3

*: #1

Azaspirodecenyl-5-14C [5-14C] NH

O

O

O O

CH3

CH3

H3C

H

O

CH3

*: #2

373.45 

IUPAC: cis-3-(2,5-

dimethylphenyl)-8-

methoxy-2-oxo-1-

azaspiro[4.5]dec-3-en-4-

yl ethyl carbonate 

CAindex: Carbonic acid, 

cis-3-(2,5-

dimethylphenyl)-8-

methoxy-2- oxo-1-

azaspiro[4.5]dec-3-en-4-

yl ethyl ester 

* Indicates labelling 
– 6 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Other radiolabels were not investigated since the pathway of degradation is sufficiently understood using 

those two radiolabels. When using the [3-14C] label (benzylic position) the metabolization could be followed 

until dimethyl-benzoic acid. An oxidative degradation leading to an elimination of the 14C atom cannot be 

envisioned without further oxidation of the phenyl system leading to small chain aliphatic compounds just 

containing C, H and O. Such compounds are relatively simple parts in the natural carbon cycle of soil.

Supportive is that high mineralization rates were described for molecules where the respective phenyl ring 

was labelled instead of the carboxyl group (in: ‘Metabolic Pathways of Agrochemicals’, TR Roberts (Ed.), 

The Royal Society of Chemistry Information Services, Cambridge, UK, 1998)). The oxidative degradation of 

the phenyl ring of aromatic compounds under ring cleavage by e. g. mono- and dioxygenases leading to 

degradates entering classical biochemical pathways like the tricarboxylic acid cycle is extensively described 

in the literature (for a review see Dagley S (1971) Catabolism of aromatic compounds by microorganisms, 

Adv. Microb. Physiol. 6, 1-46); for anaerobic degradation of respective aromatic compounds see Harwood 

CS, Burchhardt G, Herrmann H, Fuchs G (1999) Anaerobic metabolism of aromatic compounds via the 

benzoyl-CoA pathway, FEMS Microbiology Reviews 22, 439-458). Therefore, it is regarded very unlikely that 

degradates “beyond” the dimethylbenzoic acid would play any significant role in the environment. It is rather 

assumed that, as soon as all the labels carrying MA-amide derived degradates are metabolically cut down to 

the respective benzoic acids, these would quickly degrade to CO2 without the formation of any major phenylspecific degradate in soil. 

In the case of the related BCS ketoenol compound Spiromesifen (Oberon®) a third (phenyl-) label was 

investigated (in this case concerning the three-methyl-group-derived mesitylen hydrocarbon). However 

results showed that no phenyl-label specific metabolites were found. In the case of the related BCS ketoenol 

compound Spirodiclofen (Envidor®) the aerobic soil degradation of the related [14C-phenyl]-2,4-

dichlorobenzoic acid was investigated using four soils and yielded a mean DT50 value of 9.7 days. From this 

it is expected that 2,5-dimethylbenzoic acid would be degraded even faster. 

Chemical name, structure, molecule mass and occurrence of metabolites 

Chemical name, structure, molecule mass and occurrence of metabolites which were observed in 

environmental compartments or which were used as reference substances are given in Table B.8-4. 

Table B.8-3: Chemical name, structure, molecule mass and occurrence of investigated and/or 

observed metabolites of spirotetramat. 

Substance Chemical name Structure 

Mole 

mass 

[g mol-1] 

Occurrence 

(maximum amounts 

based on mean of replicates) 

[% of AR] 

Spirotetramatenol 

CAS: cis-3-(2,5-

Dimethylphenyl)-

4-hydroxy-8-

methoxy-1-

azaspiro[4.5]dec3-en-2-one 

301.39 

Aerobic soil: 100.0 

(worst case assumption) 

Aerobic outdoor: 7.8 

Anaerobic soil: 54.6

Field soil: naa

Soil photolysis: 10.1 

Hydrolysis (pH 7): 91.8

Photolysis water: 81.9

Aerobic water/sed.: 79.7 / 41.2

Spirotetramatketohydroxy 

CAS: cis-3-(2,5-

Dimethylphenyl)-

3-hydroxy-8- 

methoxy-1-

azaspiro[4.5]deca

n-2,4-dione 

317.39 

Aerobic soil: 24.0

Aerobic outdoor: 25.3

Anaerobic soil: 19.3 

Field soil: naa

Soil photolysis: 20.9

Hydrolysis: - 

Photolysis water: - 

Aerobic water/sed.: 17.4 / 42.8
– 7 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Substance Chemical name Structure 

Mole 

mass 

[g mol-1] 

Occurrence 

(maximum amounts 

based on mean of replicates) 

[% of AR] 

Spirotetramat-MAamide 

IUPAC: 2 cis-1-

[[(2,5- 

Dimethylphenyl)hy

droxyacetyl]amino

]-4-

methoxycyclohexa

necarboxylic acid 

335.40 

Aerobic soil: 5.2 

Aerobic outdoor: 6.2 

Anaerobic soil: 7.2 

Field soil: 4.5 

Soil photolysis: - 

Hydrolysis: - 

Photolysis water: - 

Aerobic water/sed.: 7.8 / 2.1 

Spirotetramatdi-hydroxy 

IUPAC: (5s,8s)-3-

(2,5-

dimethylphenyl)-

3,4-dihydroxy-8-

methoxy-1-

azaspiro[4.5]deca

n-2-one 

319.40 

Aerobic soil: - 

Aerobic outdoor: - 

Anaerobic soil: 3.2 

Field soil: - 

Soil photolysis: - 

Hydrolysis: - 

Photolysis water: - 

Aerobic water/sed.: 4.3 / 5.5 

Spirotetramatdesmethyl-enol 

IUPAC: (5s,8s)-3-

(2,5-

dimethylphenyl)-

4,8-dihydroxy-1-

azaspiro[4.5]dec3-en-2-one 

287.36 

Aerobic soil: 2.0 

Aerobic outdoor: - 

Anaerobic soil: - 

Field soil: - 

Soil photolysis: - 

Hydrolysis: - 

Photolysis water: - 

Aerobic water/sed.: - 

Spirotetramatoxo-enol 

IUPAC: 3-(2,5-

dimethylphenyl)-4-

hydroxy-1-

azaspiro[4.5]dec3-ene-2,8-dione 

285.35 

Aerobic soil: 1.1 

Aerobic outdoor: - 

Anaerobic soil: - 

Field soil: - 

Soil photolysis: - 

Hydrolysis: - 

Photolysis water: - 

Aerobic water/sed.: 6.0 / 2.3 

Dimethyl-benzoic 

acid 

IUPAC: 2,5-

Dimethyl-benzoic 

acid 

150.18 

Aerobic soil: - 

Aerobic outdoor: 3.3 

Anaerobic soil: - 

Field soil: - 

Soil photolysis: 21.8b

Hydrolysis: - 

Photolysis water: - 

Aerobic water/sed.: - 

Spirotetramatglyoxylic amide 

IUPAC: (1s,4s)-1-

{[(2,5-

dimethylphenyl)(o

xo)acetyl]amino}-

4-

methoxycyclohexa

necarboxylic acid 

333.39 

Aerobic soil: - 

Aerobic outdoor: 2.3 

Anaerobic soil: - 

Field soil: - 

Soil photolysis: 4.1 

Hydrolysis: - 

Photolysis water: - 

Aerobic water/sed.: - 
– 8 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Substance Chemical name Structure 

Mole 

mass 

[g mol-1] 

Occurrence 

(maximum amounts 

based on mean of replicates) 

[% of AR] 

4-Methoxycyclohexanone 

IUPC: 4-methoxycyclohexanone 128.17 

Aerobic soil: - 

Aerobic outdoor: - 

Anaerobic soil: - 

Field soil: - 

Soil photolysis: 10.0 

Hydrolysis: - 

Photolysis water: 17.5

Aerobic water/sed.: - 

4-Methoxycyclohexylaminocarboxylic 

acid 

IUPC: (1s,4s)-1-

amino-4-

methoxycyclohexa

necarboxylic acid 

173.21 

Aerobic soil: - 

Aerobic outdoor: - 

Anaerobic soil: - 

Field soil: - 

Soil photolysis: - 

Hydrolysis: - 

Photolysis water: 11.3

Aerobic water/sed.: - 

Spirotetramatoxo-ketohydroxy 

IUPAC: 3-(2,5-

dimethylphenyl)-3-

hydroxy-1-

azaspiro[4,5]deca

ne-2,4,8-trione 

301.35 

Aerobic soil: << 0.5 

Aerobic outdoor: - 

Anaerobic soil: - 

Field soil: - 

Soil photolysis: - 

Hydrolysis: - 

Photolysis water: - 

Aerobic water/sed.: - 

Spirotetramatphoto-cyclopentyl 

IUPAC: (1s,4s)-8'-

hydroxy-4-

methoxy-5'-

methyl-2'Hspiro[cyclohexane

-1,1'-indeno[1,2-

c]pyrrol]-3'(8'H)-

one 

NH

O

O

H

HO

299.4 

Aerobic soil: - 

Aerobic outdoor: - 

Anaerobic soil: - 

Field soil: - 

Soil photolysis: - 

Hydrolysis: - 

Photolysis water: 42.9c

Aerobic water/sed.: - 

Spirotetramatphoto-2-

methylcarbonate 

IUPAC: ethyl 2-

[(5s,8s)-8-

methoxy-2-oxo-1-

azaspiro[4.5]dec3-en-3-yl]-4-

methylbenzyl 

carbonate 

O

O

O

NH

O

O

H

373.4 

Aerobic soil: - 

Aerobic outdoor: - 

Anaerobic soil: - 

Field soil: - 

Soil photolysis: - 

Hydrolysis: - 

Photolysis water: 19.3c

Aerobic water/sed.: - 

Spirotetramatphoto-2-hydroxymethyl 

IUPAC: (5s,8s)-3-

[2-

(hydroxymethyl)-

5-methylphenyl]-

8-methoxy-1-

azaspiro[4.5]dec3-en-2-one 

NH

O

O

H

HO

301.4 

Aerobic soil: - 

Aerobic outdoor: - 

Anaerobic soil: - 

Field soil: - 

Soil photolysis: - 

Hydrolysis: - 

Photolysis water: 22.9c

Aerobic water/sed.: - 

Spirotetramatphoto-2-formyl 

IUPAC: 2-[(5s,8s)-

8-methoxy-2-oxo1-

azaspiro[4.5]dec3-yl]-4-

methylbenzaldehy

de

NH

O

O

H

O

299.4 

Aerobic soil: - 

Aerobic outdoor: - 

Anaerobic soil: - 

Field soil: - 

Soil photolysis: - 

Hydrolysis: - 

Photolysis water: 11.5c

Aerobic water/sed.: - 
– 9 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Substance Chemical name Structure 

Mole 

mass 

[g mol-1] 

Occurrence 

(maximum amounts 

based on mean of replicates) 

[% of AR] 

Spirotetramatenol-dimer 1d Not available 600 

Aerobic soil: 5.0 

Aerobic outdoor: 1.5 

Anaerobic soil: 7.0 

Field soil: < 0.2 

Soil photolysis: 2.3 

Hydrolysis: - 

Photolysis water: - 

Aerobic water/sed.: - 

Spirotetramatenol-dimer 2d Not available 600 

Aerobic soil: 3.6 

Aerobic outdoor: 0.9 

Anaerobic soil: 4.6 

Field soil: < 0.2 

Photolysis water: - 

Soil photolysis: - 

Hydrolysis: - 

Aerobic water/sed.: - 

a

 Not applicable owing to distinct storage instability of spirotetramat-enol (degrading to spirotetramat-ketohydroxy during frozen storage) 

b

 In an outdoor metabolism study, conducted with the formulation on bare soil including natural sunlight, dimethyl-benzoic acid was 

shown not to exceed 3.3 % of AR. Not considered relevant for environmental risk assessment. 

c

 Considered as photo-rearrangement products owing to the highly artificial experimental conditions (sterile buffer solution). Not 

considered to occur under environmental conditions (as demonstrated in an additional photolysis study conducted in sterile natural 

water). Not considered relevant for environmental risk assessment. 

d

 Considered as artefacts owing to hot-spot application in the laboratory, formation under environmental conditions (formulated ai) 

negligible. Not considered relevant for environmental risk assessment. 

Table B.8-4 gives an overview on metabolites of spirotetramat observed in environmental compartments 

which are considered relevant for further risk assessment (EU risk assessment). 

Table B.8-4: Summary of metabolites [maximum occurrence in % of AR] of spirotetramat considered 

relevant for a further risk assessment owing to trigger exceedance (EU risk assessment). 

Compartment Soil Soil with regard to 

groundwater 

Surface 

water Sediment 

Trigger > 10 % 

> 10 % or

2 consecutive samples > 5 % 

or 

steady increase 

> 10 % > 10 % 

Remarks 

Spirotetramat-enol 100.0a 100.0a 79.7 41.2 

Spirotetramat-ketohydroxy 24.0b 24.0b 17.4 42.8 

Spirotetramat-MA-amide <b 5.2b < < 

4-Methoxy-cyclohexanone 10.0 - - - Photolysis product 

4-Methoxy-cyclohexylaminocarboxylic acid - - 11.3 - Photolysis product 

< denotes ‘observed below the trigger’ 

- denotes ‘not observed’ 

a

 Worst-case assumption 

b

 Data derived from the spirotetramat-enol laboratory degradation study 
– 10 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

B.8.1 Route and rate of degradation in soil 

B.8.1.1 Route of degradation (OECD Annex IIA, 7.1) 

B.8.1.1.1 Aerobic degradation in soil (OECD Annex IIA, 7.1.1) 

The route of aerobic degradation (metabolism) of spirotetramat in soils was established in one laboratory 

study (which was also used for degradation rate calculations) and one supplemental outdoor study: 

• Aerobic degradation/metabolism in 4 soils (20 °C, [3-14C] label) 

• Aerobic degradation under outdoor conditions in 2 soils ([3-

14C] label) 

Further, a metabolism/degradation study was conducted with spirotetramat-enol, which is the major 

metabolite of spirotetramat. This study was performed since the parent study was not considered valid for 

quantitative distribution pattern of the metabolites owing to analytical reasons. 

• Aerobic degradation/metabolism of spirotetramat-enol in 4 soils (20 °C, [3-14C] and [5-14C] label) 

Reference: Aerobic degradation/metabolism of BYI8330 in four different soils 

Author(s), year: Babczinski, P., 2005 

Study/report number: M-256849-02-2, MEF-04/169, amended 05.05.2006 

Guideline(s): US EPA, Subdivision N, Section 162-1 (1982); OECD 307 (2002); 95/36/EC 

amending 91/414/EEC; Japanese MAFF, 12 Nohsan 8147 (2000, 2001) 

GLP: Yes 

Deviations: None 

Validity: Study considered acceptable 

Material and methods:

Test substance: [Azaspirodecenyl-3-14C]-spirotetramat (sample ID: BECH 0755); specific 

radioactivity 3.71 MBq mg-1 (100.2 μCi mg-1); Radiochemical purity: > 99 % (acc. 

radio-HPLC and -TLC); chemical purity: > 99 % (HPLC, UV detection at 210 nm); 

identity and purity of the stock solution was checked 

Reference substances: Spirotetramat (unlabelled), spirotetramat-enol, spirotetramat-ketohydroxy, 

spirotetramat-MA-amide, spirotetramat-desmethyl-enol, spirotetramat-oxo-enol, 

mandelic acid, dimethyl-benzoic acid, spirotetramat-enol-dimer 1 

Test system: Static incubation test system 

Acclimatisation time: 20 – 39 days (application 37 - 42 days after sampling) 

Test conditions: Aerobic conditions; for ‘Molino’ soil (US soil, metabolism soil) replicates were set 

up, for EU soils (kinetic soils) all sampling dates except of DAT-0 were analyzed 

via single test flasks 

Moisture adjusted soils (50 % MWHC [EU soils] or 75 % of 1/3 bar moisture [US 

soil]) maintained at 20 ± 1 °C in the dark. At DAT-0 the absolute microbial 

biomass carbon contents corresponded to 6.4, 3.1, 2.6 and 1.9 % relative to the 

soil organic carbon content of the soils ‘Hoefchen’, ‘Laacherhof AXXa’, 

‘Laacherhof AIII’ and ‘Molino’, respectively 

Test duration: EU soils – 50 days; the EU soils experiments were terminated earlier as after one 

or two weeks at least 90 % of the test item was transformed and at least > 5 % 

CO2 was formed (according OECD 307) 

US soil – 360 days (according EPA § 162-1) 

Sampling intervals: EU soils – 0 (duplicate sample), 0.25, 1, 3, 7, 14, 30 and 50 days (single samples) 

US soil – 0, 0.25, 1, 3, 7, 14, 30, 50, 86, 126, 179, 270 and 360 days (duplicate 
– 11 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

samples) 

Application: EU soils – 0.128 mg kg-1 (nominal) dry soil, US soil – 0.768 mg kg-1 (nominal) dry 

soil, equivalent to 0.288 kg ai ha-1 (calculation based on homogeneous distribution 

for 2.5 cm soil depth [EU soils] and 15 cm soil depth [US soil] and 1.5 g cm-3 soil 

density); supplied test item was dissolved in 2 mL acetonitrile 

A so-called “hot spot application” (soil spiking by a pipette with a low volume of 

higher concentrated organic test solution) was used as the test item is highly 

degradable and has a low water solubility 

Analyses: Ambient extraction procedure: 100 g dry mass (DM) soil samples were extracted 3

times with 80 mL of acetonitrile/water (1:1, v/v, containing 0.5 % formic acid) 

Aggressive extraction procedure: To obtain information about the bound residues 

the residual soil already extracted using the ambient procedure was additionally 

extracted twice with 80 mL of acetonitrile/1N hydrochloric acid (1:1, v/v, pH ca. 1). 

Finally the samples were extracted with pure acetonitrile (1 x 50 mL) using the 

same technique. 

The spirotetramat residues were radio-assayed by LSC and analyzed separately 

in the combined ambient and combined aggravated extracts by HPLC on reversed 

phase (C-18) columns. Solid samples (i.e. soil and paper filters) were combusted 

and 14C levels were measured using LSC. In order to identify parent compound 

and the transformation products co-chromatography and spectrometric methods 

were used. 

Volatile traps: Organic volatiles: polyurethane foam, CO2: soda lime, CO2 identity confirmed by 

BaCO3 precipitation 

Analytical techniques: LSC, RP-HPLC, Si-60 silica TLC, LC-MS/MS, NMR 

Detection limits: For LSC: LOQ ≤ 0.2 % of AR, for CO2 samples LOQ < 0.1 % of AR; 

for HPLC: LOQ ≤ 0.2 % of AR 

Kinetic evaluation: Simple first order (SFO) kinetics; ModelManager, vers. 1.1., C0 calculated by the 

model; only parent modelled 

Table B.8.1.1.1-1: Main soil properties. 

Parameter ‘Molino’ ‘Laacherhof 

AXXa’ 

‘Laacherhof 

AIII’ ‘Hoefchen’ 

Source Florida, USA Monheim, 

Germany 

Monheim, 

Germany 

Burscheid, 

Germany 

Texture (USDA) Tifton fine 

sandy loam Sandy loam Silt loam Silt 

Soil taxonomic classification (USDA) 

Fine-loamy, 

kaolinitic, 

thermic 

Plinthic 

Kandiudults 

Sandy, mixed, 

mesic Typic 

Cambudolls 

Loamy, mixed, 

mesic Typic 

Argudalfs 

Loamy, mixed, 

mesic Typic 

Argudalfs 

SCS soil series Ultisol Mollisols, 

Udolls Alfisols, Udalfs Alfisols, Udalfs

Sand (USDA) [%] 77.3 72.4 36.9 8.5 

Silt (USDA) [%] 12.7 22.6 51.1 81.3 

Clay (USDA) [%] 10.0 5.0 12.0 10.2 

pH (H2O) 6.1 7.2 7.4 7.6 

pH (CaCl2) 5.4 6.3 6.5 6.7 

pH (KCl) nd 6.4 nd 7.0 

Organic matter [%] 1.60 1.75 1.43 3.63 

Organic carbona [%] 0.93 1.02 0.83 2.11 

Carbonate (CaCO3) [%] < 0.1 < 0.1 < 0.1 0.9 

CEC [meq/100 g DM] 6 8 8 15 

WHC at pF2.5 (FC at 0.33 bar) [g/100 g DM] 18.4 29.1 20.7 35.6 
– 12 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Parameter ‘Molino’ ‘Laacherhof 

AXXa’ 

‘Laacherhof 

AIII’ ‘Hoefchen’ 

MWHC [g/100 g DM] Not available 34.4 36.4 63.1 

Microbial Cb [mg microbial C/kg soil DM] start 180 312 213 1341

Microbial Cb [mg microbial C/kg soil DM] DAT-59 118 261 202 730 

Microbial Cb [mg microbial C/kg soil DM] DAT-360 77 - - - 

nd denotes not determined 

a

 Organic C = organic matter / 1.724 

b

 Substrate induced respiration 

Since preliminary experiments with a so-called ‘bulk soil application’ showed low DAT-0 recoveries and the 

test item and/or its degradate(s) quickly degraded and firmly bound to the soil, for the present study a socalled ‘hot-spot’ application was used. Due to this application form an immediate DAT-0 extraction was

possible with high efficiency (93.1 to 99.6 %). 

Under the used acidic extraction solvents the test item showed good stability values whereas the major soil 

degradate spirotetramat-enol showed an instability under these processing conditions. Using slightly alkaline 

conditions, enol degradation could be largely prevented (additional experiment, Figure B.8.1.1.1-1). In the 

absence of soil, spirotetramat-enol was stable under both the acidic and alkaline processing conditions. 

However, alkaline processing conditions would be detrimental for the stability of the parent compound.

Therefore, within this parent degradation study it was not possible to use a processing procedure 

guaranteeing for the stability of the parent and its major degradation product. To overcome these difficulties, 

an additional aerobic degradation study using an alkaline extraction procedure for spirotetramat-enol was 

conducted (see separate study, Babczinski, 2006b). 

Figure B.8.1.1.1-1: Additional experiment: 

0-DAT recovery of applied spirotetramat-enol 

using acidic or slightly alkaline extraction. 

Findings:

All values are given as mean values of the replicates. 

Total mass balance was in the range of 85.7 % to 100.5 % of AR whereas only two out of 37 mass balance

values were below 90 % (85.7 and 86.8 %). 

At the end of the incubation time the amount of 14CO2 reached 15.3 % of AR in soil ‘Molino’ (DAT-360) and 

12.2 to 19.4 % of AR in the EU soils (DAT-50). The highest CO2 formation rate was formed in the soil 

‘Hoefchen’ expected due to its highest content of microbial biomass. Compared to the other soils, soil

‘Molino’ showed at DAT-50 the lowest mineralization rate. No other volatile compounds were detected. 
– 13 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

The portion of non-extractable radioactivity (NER) rapidly increased reaching its peaks at levels of 21.3 % 

of AR to 35.2 % of AR after one to three days after application. At the termination of the studies (US soil: 

DAT-360, EU soils: DAT-50) bound residues reached a level of 21.5 % of AR to 31.0 % of AR. The highest

value was measured in ‘Molino’ soil (mean value 35.2 % of AR, DAT-3). A partitioning of the heterogeneous 

NER into humic acid, fulvic acid and humin like fractions was observed, with a major portion belonging to the 

fulvic acid fraction and with a significant portion bound to soil in the insoluble humin fraction. 

Under standard conditions (20 ± 1 °C, 50 % MWHC [EU soils] or 75 % of 1/3 bar moisture [US soil]) a rapid 

decline of spirotetramat was observed in all four soils, dropping below 10 % of AR after one day. It was 

shown that the degradation of spirotetramat correlates with the soil biomass content indicating that the 

degradation is, at least in part, microbial. The fast decline of the parent was accompanied in all soils by a 

rapid appearance of the major degradates spirotetramat-enol (max. 24.3 % of AR, DAT-3) and 

spirotetramat-ketohydroxy (max. 16.3 % of AR, DAT-1). Beside of these two main metabolites two 

spirotetramat-enol-dimers (spirotetramat-enol-dimer 1: max. 12.7 % of AR, DAT-7; spirotetramat-enoldimer 2: max. 9.2 % of AR, DAT-30) and spirotetramat-MA-amide (max. 6.4 % of AR, DAT-179) were 

identified. Two minor metabolites were spirotetramat-desmethyl-enol (max. 3.7 % of AR, DAT-30/179) and

spirotetramat-oxo-enol (max. 1.2 % of AR, DAT-50). Further, the large number of minor peaks (not identified) 

were summed up under unidentified radioactivity (max. single peak < 5 % of AR). 

It was not possible to calculate valid DT50 values for the soil degradates due to plateauing towards study 

termination in several cases. This effect was explained by several reasons: influence of the microbiological 

activity due to the application solvent, the “hot-spot” application has caused ‘artifactual’ formation of some 

transformation products (enol-dimers), influence of the level of spirotetramat-enol and other degradates due 

to reformation of spirotetramat-enol from spirotetramat-enol-dimers and due to the chosen processing 

procedure (acidic extraction procedure) which is expected as partly destructive for the spirotetramat-enol, 

respectively. For these reasons, separate studies using spirotetramat-enol as test item were performed. The 

metabolite kinetics is not assessed in detail within this study. The calculated DT50 values of spirotetramat are 

listed in Table B.8.1.1.1-6. 

Dimeric spirotetramat-enol soil “degradates”: 

The dimerization issue is discussed in detail under point B.8.11 (position paper Hellpointner et al., 2007). 

Metabolic pathway: 

Spirotetramat was metabolized via three degradation pathways which all started with the hydrolytic cleavage 

of the spirotetramat ester into the spirotetramat-enol. In the major degradation pathway the spirotetramatenol will be oxidized at the benzylic carbon position into spirotetramat-ketohydroxy which is hydrolytically 

opened into the spirotetramat-MA-amide and finally mineralized into CO2. In the second (minor) pathway, 

demethylation of the spirotetramat-enol into spirotetramat-desmethyl-enol and oxidation of this degradate 

into the spirotetramat-oxo-enol occurred. In a third degradation pathway, the spirotetramat-enol-dimer 1 and 

spirotetramat-enol-dimer 2 were pretended to be built through oxidative enol dimerization, but this pathway is 

regarded as non relevant under environmental conditions (for more detailed information see point B.8.11, 

position paper Hellpointner et al., 2007). 
– 14 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.1.1-2: Distribution and recovery of applied radioactivity [% of AR] after application of 

[3-14C] labelled spirotetramat to 4 soils (mean of duplicate samples in ‘Molino’ soil). 

Extractable 

Soil DAT Organic/ 

aqueous extract 

Aggravated 

extract Total 

CO2 NER Total 

0 94.2 3.5 97.7 nd 0.4 98.1 

0.25 68.1 12.2 80.3 0.5 19.7 100.5 

1 40.1 22.8 63.0 1.7 31.8 96.5 

3 30.0 25.7 55.7 3.7 35.2 94.6 

7 30.4 25.8 56.2 5.9 33.0 95.1 

14 27.1 24.8 51.9 7.6 30.5 90.1 

30 33.1 24.3 57.5 8.4 31.5 97.4 

50 31.1 24.6 55.6 9.7 30.3 95.6 

86 30.6 24.3 54.9 15.5 29.9 100.4 

126 31.9 26.6 58.5 12.1 27.6 98.2 

179 28.9 24.0 52.8 15.4 27.8 96.0 

270 29.5 25.7 55.1 14.8 27.2 97.1 

‘Molino’ 

360 26.0 25.9 51.8 15.3 27.0 94.2 

0

a

93.1 2.9 96.0 nd 0.1 96.2 

0.25 62.1 8.0 70.1 0.3 16.4 86.8 

1 53.8 11.9 65.7 1.8 27.2 94.8 

3 55.7 12.0 67.7 3.1 25.4 96.1 

7 50.0 12.4 62.3 6.3 26.2 94.8 

14 43.6 9.5 53.1 8.3 24.3 85.7 

30 42.5 12.1 54.6 10.0 27.9 92.5 

‘Laacherhof 

AXXa’ 

50 44.2 12.7 56.9 12.2 25.5 94.7 

0

a

91.8 2.6 94.4 nd 0.1 94.5 

0.25 72.8 8.2 81.1 0.2 14.1 95.4 

1 61.1 10.9 71.9 1.5 21.3 94.7 

3 60.7 12.5 73.2 3.0 21.0 97.1 

7 63.6 10.9 74.6 2.1 19.0 95.7 

14 57.8 11.1 68.9 6.9 17.4 93.2 

30 55.0 11.3 66.3 10.7 20.6 97.6 

‘Laacherhof 

AIII’ 

50 49.1 13.6 62.7 15.4 21.5 99.6 

0

a

94.8 3.5 98.2 nd 0.3 98.5 

0.25 49.6 16.3 65.8 0.3 32.3 98.4 

1 48.7 15.1 63.8 1.3 30.9 96.0 

3 39.2 18.7 57.9 3.2 34.5 95.6 

7 41.4 19.9 61.3 4.8 32.8 99.0 

14 27.7 18.3 46.1 11.4 33.8 91.2 

30 30.3 18.7 49.1 13.3 34.6 97.0 

‘Hoefchen’ 

50 28.4 18.8 47.2 19.4 31.0 97.6 

nd denotes not determined 

a

 Mean of duplicate samples 

Table B.8.1.1.1-3: Characterization [% of AR] of non-extractable soil residues (NER). 

Sampling DAT-3 DAT-7 DAT-30 DAT-50a

Soil ‘Hoefchen’ ‘Molino’ ‘Laacherhof AXXa’ ‘Laacherhof AIII’ 

Total NER 33.8 32.4 27.0 20.9 

Fraction humic acids 11.2 13.5 9.7 3.9 

Fraction fulvic acids 16.0 16.7 12.9 12.8 

Fraction humin substances 8.6 5.6 5.0 4.2 

Processing balance [%] 105.7 110.2 102.1 100.1 

a

 ‘DAT-60’ stated in the original report probably a typo 
– 15 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.1.1-4: Characterization of extractable radioactivity [% of AR] after application of [3-14C] labelled spirotetramat to ‘Molino’ soil (individual 

replicates). 

Spirotetramat Spirotetramat- desmethyl-enol Spirotetramat- oxo-enol Spirotetramat- enol Spirotetramat- enol-dimer 1 Spirotetramat- enol-dimer 2 Spirotetramat- ketohydroxy Spirotetramat- MA-Amide Unidentifieda Soil DAT 

A B A B A B A B A B A B A B A B A B 

0 93.5 98.6 nd nd nd nd nd nd nd nd nd nd nd nd nd nd 2.3 1.0 

0.25 56.2 48.1 nd nd nd nd 4.4 5.6 nd nd nd nd 6.6 9.4 0.3 0.7 14.2 15.1 

1 15.0 15.7 0.9 1.2 nd nd 8.8 9.6 0.6 0.5 1.3 1.6 7.5 9.8 2.1 2.8 27.1 21.4 3 8.1 5.9 0.9 1.1 nd 0.3 11.1 15.4 1.1 0.3 0.5 0.6 10.6 13.5 1.7 2.2 22.7 15.5 7 7.2 5.8 3.8 2.4 nd 1.0 10.3 10.7 1.7 1.6 0.4 0.4 12.8 10.8 4.1 4.3 16.7 18.4 

14 4.5 4.5 2.1 1.3 0.6 0.9 9.4 7.8 3.6 2.0 2.2 0.9 7.6 7.9 3.5 4.9 21.2 19.0 30 5.8 4.3 2.9 4.5 nd nd 5.2 7.2 3.4 2.8 2.1 1.5 9.4 9.3 5.6 5.3 21.9 23.7 50 3.9 4.2 3.1 2.0 nd 1.2 8.2 6.6 3.5 2.1 2.8 1.0 10.8 9.0 5.2 4.7 19.0 24.0 86 3.7 3.7 4.3 2.3 nd nd 7.0 4.0 1.6 1.5 3.2 1.3 12.6 8.6 5.1 5.7 18.3 26.7 

126 3.3 2.6 3.1 3.3 nd nd 6.5 8.2 3.0 1.3 1.4 0.6 12.7 15.7 5.4 6.6 21.2 22.2 179 3.7 3.3 3.8 3.7 0.8 nd 4.9 4.2 2.0 1.6 1.7 0.9 13.5 8.6 6.6 6.2 17.4 22.7 270 2.4 4.0 3.5 2.7 nd nd 3.6 4.9 1.2 0.9 1.6 nd 11.2 14.2 5.5 7.0 25.8 21.7 

‘Molino’ 

360 3.5 3.5 0.9 2.0 nd nd 2.5 2.9 0.5 0.4 0.9 0.7 13.7 13.5 7.0 5.4 24.1 22.2 

nd denotes not determined a Up to 18 HPLC peaks/DAT; max. value for a single peak: 4.0 % of AR 
– 16 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.1.1-5: Characterization of extractable radioactivity [% of AR] after application of [3-14C] labelled spirotetramat to ‘Laacherhof AXXa’, 

‘Laacherhof AIII’ and ‘Hoefchen’ soil (HPLC, no replicates available). 

Soil DAT Spirotetramat 

Spirotetramatdesmethylenol Spirotetramat- oxo-enol Spirotetramat- enol Spirotetramat- enol-dimer 1 Spirotetramat- enol-dimer 2 Spirotetramat- ketohydroxy Spirotetramat- MA-amide Unidentifieda

0b 91.8 nd nd nd nd nd nd nd 4.3 

0.25 38.3 0.2 nd 6.8 2.3 3.1 10.6 0.4 8.4 

1 8.3 1.9 nd 18.8 2.4 6.2 16.3 2.3 9.7 3 3.1 1.5 1.0 19.0 3.5 5.0 14.8 3.0 16.9 7 3.5 2.7 nd 11.9 7.0 2.7 12.8 6.0 15.8 

14 2.6 1.6 0.4 10.2 7.0 5.7 7.4 4.4 13.7 30 2.2 2.6 nd 8.8 7.4 5.5 5.1 3.5 19.5 

‘Laacherhof 

AXXa’ 

50 2.5 1.8 nd 9.5 7.5 6.9 5.9 3.1 19.6 

0b 91.6 nd nd nd nd nd nd nd 2.8 

0.25 41.2 nd nd 9.4 4.4 4.2 10.5 0.2 11.1 

1 8.9 0.4 nd 20.8 3.3 7.2 15.0 1.9 14.3 3 3.4 nd nd 24.3 3.5 6.3 14.3 3.1 18.2 7 3.5 2.7 nd 15.1 12.7 4.2 12.9 5.4 18.1 

14 2.8 1.9 nd 15.5 9.4 8.9 8.4 3.9 18.2 30 3.0 2.1 nd 11.4 9.8 9.2 6.6 3.3 20.8 

‘Laacherhof 

AIII’ 

50 3.4 2.3 nd 9.9 7.7 8.1 5.6 3.3 22.3 

0b 93.2 nd nd nd nd nd nd nd 5 

0.25 11.6 1.0 0.6 11.6 4.3 3.7 14.7 2.4 16 

1 5.8 0.6 nd 17.2 2.1 3.8 9.4 2.8 22.2 3 1.9 1.7 nd 16.9 2.5 2.1 11.8 4.8 16.0 7 3.7 2.3 1.1 14.1 5.7 1.6 11.0 5.3 16.4 

14 2.0 2.3 0.4 8.4 4.2 3.5 4.3 2.8 18.2 30 2.1 1.6 nd 9.8 5.5 3.8 3.8 2.0 20.5 

‘Hoefchen’ 

50 2.6 1.6 nd 10.4 4.9 6.0 2.4 1.1 18.3 

nd denotes not determined a Total % of AR for unidentified discrete components and streaking, none exceeding 5 % of AR individually b Mean of two replicates 
– 17 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.1.1-6: Calculated DT50 and DT90 values [days] of [3-14C] labelled spirotetramat in 4 soils 

based on SFO kinetics. 

Soil DT50 [days] DT90 [days] R2 Kinetics 

‘Molino’ 0.327 1.090 0.974 SFO 

‘Laacherhof AXXa’ 0.210 0.697 0.991 SFO 

‘Laacherhof AIII’ 0.232 0.770 0.989 SFO 

‘Hoefchen’ 0.083 0.277 0.991 SFO 

Conclusion:

Spirotetramat was shown to rapidly biodegrade in all four tested soils (1 US soil and 3 EU soils) under 

standard aerobic conditions, applied at a concentration equivalent to 0.288 kg ai ha-1. Dissipation followed 

SFO kinetics with calculated half-lives of 0.08 – 0.33 days at 20 °C. The evolved 14CO2 (no volatile organics) 

was about 12.2 – 19.4 % of AR at study termination (DAT-50, EU soils) whereas soil ‘Hoefchen’ showed the 

highest mineralization rate pretended caused by its highest content of microbial biomass. The US soil 

accounted for 9.7 % of AR (DAT-50) and increased to 15.3 % of AR at study termination (DAT-360). Besides 

14CO2 a portion of the applied radioactivity was found to be integrated into NER (max. 35.2 % of AR in soil 

‘Molino’, mean value/DAT-3). This portion of radioactivity timely occurs very fast after application. 

Fractionation demonstrated the NER residue to be of heterogeneous nature with a major portion belonging 

to the fulvic acid fraction. The metabolites were identified as spirotetramat-enol (max. 24.3 % of AR, mean 

value, DAT-3), spirotetramat-ketohydroxy (max. 16.3 % of AR, mean value, DAT-1), spirotetramat-enoldimer 1 (max. 12.7 % of AR, mean value, DAT-7), spirotetramat-enol-dimer 2 (max. 9.2 % of AR, mean 

value, DAT-30), spirotetramat-MA-amide (max. 6.4 % of AR, mean value of replicates, DAT-179), 

spirotetramat-desmethyl-enol (max. 3.7 % of AR, mean value, DAT-179) and spirotetramat-oxo-enol (max. 

1.2 % of AR, mean value, DAT-7). 

In the context of the relevance as soil ‘major’ metabolites (> 10 % of AR), spirotetramat-enol and 

spirotetramat-ketohydroxy should be taken into account. With regard to the groundwater also spirotetramatMA-amide has to be considered further (following the trigger for the EU risk assessment). The spirotetramatenol-dimers are regarded as artifactual degradates (for details refer to B.8.11, position paper Hellpointner et 

al., 2007) and, therefore, both are not relevant for further consideration. 

It was assumed that the present study gives just valid data related to the disappearance of spirotetramat, but 

not the true quantitative distribution pattern of the metabolites resulting from the rapidly formed spirotetramatenol. Consequently, the kinetic evaluation was based on the spirotetramat-enol study (Babczinski, 2006b), 

which avoids the existing enol-stability problems (acidic extraction conditions needed for spirotetramat) in the 

parent study. Further, the artificial hot spot/organic solvent application needed in the parent study leading to 

artificially high dimer amounts were regarded as uncertainty factors in the metabolic profiling (see B.8.11, 

position paper Hellpointner et al., 2007). 

A second label study was considered unnecessary since significant mineralization was observed and no 

metabolite indicated molecule breakage at significant amounts. 

Reviewer comments:

• More detailed information on the dimerization issue is summarized under point B.8.11 (Position 

paper Hellpointner et al., 2007).

• Degradation kinetics of the parent was re-calculated in a separate study (Ramanarayanan and 

Röpke, 2006). 

• Owing to the observed instability of spirotetramat-enol under the acidic extraction used in this study, 

the additionally conducted spirotetramat-enol degradation study (Babczinski, 2006b), which avoids 

these problems, is considered the only reliable basis for the determination of maximum occurrence 
– 18 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

and kinetic behaviour of spirotetramat-enol and the subsequent metabolites (spirotetramatketohydroxy and spirotetramat-MA-amide) in aerobic soils degradation. 

• On request the notifier (BCS) provided further information in respect to the 

identification/characterization of the NER fraction:

BCS: The studies were conducted according to established guidelines. Harsh extraction 

methods were employed to extract as much of NER from the soil as possible. The aggressive 

method used in the current study (2 times ACN/1 N HCl, pH 1) solubilized a lot of the soil matrix 

(dark brown extracts). Further strong alkaline extraction (0.5 M NaOH) was conducted for BR 

characterization as humic and fulvic substances. These treatments are considered as adequate 

for BR identification/ characterization in the sense of citations [1] to [5] [see below]. Any new 

methods to characterize NER (or BR) would not add much value to the risk assessment 

because NER is immobile and not readily bioavailable or bioaccessable. 

[1] FOCUS (2006) “Guidance document on estimating persistence and degradation kinetics from 

environmental fate studies on pesticides in EU registration” Report of the FOCUS Work Group on 

Degradation Kinetics, EC Document reference Sanco/10058/2005 version 2.0

[2] SETAC (1995) Procedures for assessing the environmental fate and ecotoxicity of pesticides, ed. M R 

Lynch

[3] Pesticide Reregistration Rejection Rate Analysis Environmental Fate, US EPA, EPA 738-R-93-0110, 

1993

[4] ECPA Position Paper on Soil Non-Extractable Residues, Brussels, March 3, 2000, D/00/SuM/5277

[5] SCP Opinion on Draft GD on persistence in soil (DG IY-9188/IV/97-Rev. 5, 1998) dated 1999
– 19 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Reference: Outdoor Metabolism of [Azaspirodecenyl-3-14C]BYI08330 in two soils 

Author(s), year: Babczinski, P., 2006a 

Study/report number: M-270597-01-2, MEF-06/041 

Guideline(s): Supportive non-guideline study, but approached to US EPA, Subdivision N, 

Section 162-1 (1982); OECD 307 (2002); EC-Directive 91/414/EEC Annex I Part 

7 and Annex II Part 9; SETAC Procedures for Assessing the Environmental Fate 

and Ecotoxicity of Pesticides. 

GLP: Yes 

Deviations: None 

Validity: Study considered acceptable 

Material and methods:

Test substance: [Azaspirodecenyl-3-14C]-spirotetramat (sample ID: BECH 1569); specific 

radioactivity 3.67 MBq mg-1 (99.1 mCi mg-1); radiochemical purity: > 99 % (acc. 

radio-HPLC) and > 98 % (acc. radio -TLC); identity and purity of the stock solution 

was checked 

Reference substances: Spirotetramat (unlabelled), spirotetramat-enol, spirotetramat-ketohydroxy, 

spirotetramat-MA-amide, spirotetramat-glyoxylic-amide, dimethyl-benzoic acid, 

methoxycyclohexanone, glyoxylic amide, spirotetramat-enol-dimer 1, 

spirotetramat-enol-dimer 2 

Test system: Two semi-disturbed (without sieving) soils (‘Laacherhof AIII’ [EU soil] and ‘Molino’ 

[US soil]) were poured into a planting container approx. 1 m2 area which was 

divided into two halves by a separating plate. Soils were placed for 127 days 

under outdoor climatic conditions (open system, protected for rainfall, exposed to 

natural temperature, humidity and light-dark cycles). The bottom was open for 

drainage. Non-balance-study since no volatiles and residues other than those in 

the treated soil were addressed; the soils were kept bare and free of weeds, and 

irrigation was performed for adequate moisture. 

Test duration: 127 days (sampling intervals: 1, 7, 14, 28, 63, 127 days (207 days – for TRR 

determination only) 

Application: [Azaspirodecenyl-3-14C]-spirotetramat formulated as an OD 100 was applied at 

94.6 % of the highest recommended single use rate for field application (288 

g/ha); application was carried out using a computer controlled track sprayer fitted 

with a flat fan nozzle. Application date: 2004-06-28 

Weather data: 

Sampling: Four soil cores (5 cm in diameter, 20 cm in depth) were randomly taken from each 

half of the soil container at each sampling date. The upper 10 cm of the sampled 

soil cores were air-dried at ambient temperature (overnight), homogenized and 

their dry weight determined. Then a tenth of the weight of each core was taken, 

combined and mixed, and the mixed sample used for extraction. The remaining 

sample was used for TRR determination by combustion/LSC. 

Analyses: Soil samples were extracted three times with acidic acetonitrile/water/formic acid 

(1000/1000/1 each 80 mL, conventional method), followed by twice acetonitrile/1N 

HCl (1/1; each 80 mL, aggressive method). Conventional and aggressive extracts 
– 20 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

were combined, radio-assayed by LSC and analyzed separately in the combined 

ambient and combined aggravated extracts by HPLC. From DAT-28 on, the 

profiling HPLC method was changed (original HPLC method 2 [Kromasil] was 

replaced by HPLC method 1 [Purospher]). Therefore, all extracts from DAT-1, 

DAT-7 and DAT-14 were either re-analyzed (DAT-7) or newly processed after 

storage of the original extract in a freezer (DAT-1, DAT-14), and the spirotetramat 

residues were analyzed by HPLC. Radio-TLC was used for confirmatory 

identification of isolated metabolites only (i.e. HPLC cuts spiked with nonradiolabelled referenced substances). Identification of the transformation products 

was performed by co-chromatography with reference substances and LC/MS 

spectrometry. Since the study was conducted under outdoor conditions, collection 

of 14CO2 and volatile organic compounds was not possible, and therefore, the total 

recovered radioactivity was lower than the total applied radioactivity (100 % of 

AR). Solid samples (i.e. soil and paper filters) were combusted and 14C levels 

were measured using LSC. 

Detection limits: LSC: LOQ < 0.1% of AR, HPLC: LOQ ≤ 0.3 % of AR. 

Analytical techniques: LSC, RP-HPLC, Si-60 silica TLC, LC-MS, LC-MS/MS, NMR 

Kinetic evaluation: Single first order (SFO) kinetics; ModelManager, vers. 1.1., C0 was set to 100 % 

Table B.8.1.1.1-7: Main soil properties. 

Parameter ‘Laacherhof AIIIa’ ‘Molino’ 

Location Germany USA, Florida 

Texture (USDA) Loam Sandy loam 

Soil taxonomic classification (USDA) Loamy, mixed, mesic 

Typic Argudalfs 

Fine-loamy, kaolinitic, 

thermic Plinthic 

Kandiudults 

SCS soil series Alfisols, Udalfs Ultisol 

Sand (USDA) [%] 44.7 77.9 

Silt (USDA) [%] 38.3 13.6 

Clay (USDA) [%] 17.1 8.6 

pH (in water) 7.4 6.0 

pH (in CaCl2) 6.7 5.4 

pH (in KCl) 6.7 5.4 

Organic matter [%] 1.7 1.4 

Organic carbona [%] 1.0 0.8 

Carbonate (CaCO3) [%] < 0.1 < 0.1 

CEC [meq/100 g DM] 9.3 4.2 

MWHC [g/100 g DM] 45.6 22.6 

Soil biomassb [mg microbial C/kg soil DM] DAT-2 349 99 

Soil biomassb [mg microbial C/kg soil DM] DAT-127 301 55 

a

 Organic C = organic matter / 1.724 

b

 Substrate induced respiration 

Findings:

The total radioactive residues (TRR) ranged from 73.8 to 24.9 % of AR for loam soil ‘Laacherhof AIIIa’ at 

DAT-1 and DAT-127, respectively. The corresponding values for soil ‘Molino’ were 94.6 to 22.8 % of AR after 

the two respective sampling intervals. Radioactive losses by mineralization, volatilization or translocation 

were not determined since the study was conducted under outdoor conditions in an “open system”. No 

drainage water was obtained during the study. From the results of other degradation studies (e.g. 

Babczinski, P., 2005) it can be concluded that a main dissipation path will be via mineralization to 14CO2

rather than volatilization or leaching (Babczinski, P., 2006c). Two inconsistent TRR values (at DAT-63 [soil 

‘Laacherhof AIIIa’] and DAT-127 [soil ‘Molino’]) were obtained probably caused by a local inhomogenity

during application. Therefore, additional TRR determination was performed late after the termination of the 
– 21 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

regular study (DAT-127), at DAT 207. These values were mentioned as outliers and were therefore corrected 

by interpolation. The corrected values were used for kinetic evaluation. 

Non-extractable residues increased up to 13.2 % and 16.8 % of AR in the two soils at DAT-28 and DAT-63, 

respectively, and then decreased towards the end of the study to 8.5 % and 5.4 % of AR in the two soils, 

respectively. No 14CO2 were measured since the outdoor study design did not allow for analysis of volatile 

radioactivity. 

Kinetics analyses showed that spirotetramat degraded rapidly with a DT50 of 1.2 and 2.9 days in soils 

‘Laacherhof AIIIa’ and ‘Molino’, respectively (mean 2.1 days). The calculated DT90 values were about 4.1 and 

9.6 days (mean 6.9 days), respectively. During the course of the study a large number of degradates was 

observed in both soils (at maximum 39 HPLC regions of interest [ROIs] were set at a single sampling 

interval). The total unidentified radioactivity consisted on maximum of 14 and 29 HPLC ROIs and diffuse 

radioactivity per sampling interval for soils ‘Laacherhof AIIIa’ and ‘Molino’, respectively. 

As major degradate spirotetramat-ketohydroxy (max. 25.3 % of AR, DAT-14) was detected. Spirotetramatenol was detected with max. 7.8 % of AR (DAT-7). As minor degradates were identified: spirotetramat-MAamide (max. 6.2 % of AR, DAT-28), dimethyl-benzoic acid (max. 3.3 % of AR, DAT-7), spirotetramatglyoxylic amide (max. 2.3 % of AR, DAT-7), spirotetramat-enol-dimer 1 (max. 1.5 % of AR, DAT-28), 

spirotetramat-enol-dimer 2 (max. 0.9 %, DAT-7) and spirotetramat-ketohydroxy-carboxy (max. 1.3 % of AR). 

All minor non-identified degradates accounted for maximum 2.1 % of AR. 

Table B.8.1.1.1-8: Distribution and recovery of applied radioactivity [% of AR] after application of 

[3-14C] labelled spirotetramat to two soils under realistic outdoor conditions. 

Soil DAT Extractable CO2/volatiles NER Total 

1 69.2 na 4.6 73.8 

7 63.9 na 9.8 73.7 

14 54.6 na 7.9 62.5 

28 46.8 na 13.2 60.0 

63 34.9 na 8.4 43.3 

‘Laacherhof AIIIa’ 

127 16.4 na 8.5 24.9 

1 87.2 na 7.3 94.6 

7 64.5 na 15.2 79.7 

14 62.2 na 10.6 72.8 

28 50.6 na 14.6 65.2 

63 29.1 na 16.8 46.0 

‘Molino’ 

127 17.4 na 5.4 22.8 

na denotes not applicable for this kind of study (‘open system’) 
– 22 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.1.1-9: Characterization of extractable radioactivity [% of AR] after application of [3-14C] labelled spirotetramat to two soils under realistic 

outdoor conditions. 

Dose DAT Spirotetramat Spirotetramat- enol Spirotetramat- ketohydroxy Spirotetramat- MA-amide Spirotetramat- glyoxylic amide Dimethyl- benzoic acid Spirotetramat- enol-dimer 1 Spirotetramat- enol-dimer 2 Unidentifieda

1 53.6 2.5 6.6 nd 0.8 1.0 1.1 nd 3.6 7 13.4 5.9 22.7 2.6 2.3 3.3 1.3 0.9 11.6 

14 3.8 3.3 23.6 3.6 1.6 3.0 1.4 0.6 13.7 28 2.5 1.5 10.5 6.2 1.1 2.1 1.5 0.7 20.8 63 2.5 1.0 14.2 2.0 nd 0.4 0.4 0.3 14.1 

‘Laacherhof 

AIIIa’ 

127 1.0 0.5 1.9 2.8 nd 0.5 nd nd 9.7 

1 72.2 3.8 5.0 0.2 0.2 0.3 0.8 0.3 4.2 7 17.8 7.8 20.4 1.8 0.6 1.2 1.1 0.9 13.0 

14 10.2 5.4 25.3 1.9 0.7 2.1 0.8 0.4 15.4 28 4.5 1.9 20.5 2.0 0.6 0.9 1.5 0.6 18.3 63 1.4 0.9 3.1 4.9 0.7 1.0 0.2 0.2 16.7 

‘Molino’ 

127 1.0 0.4 8.0 1.0 < LOQ 0.3 < LOQ < LOQ 6.6 

nd denotes not detected LOQ denotes limit of quantification a Up to 29 detected regions, values for a single non-identified region were < 2.1% of AR 
– 23 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.1.1-10: Calculated DT50 and DT90 values [days] of [3-14C] labelled spirotetramat in two 

soils under realistic outdoor conditions based on SFO and DFOP (best fit) kinetics. 

Application rate 

[g ha-1] Soil DT50

[days] 

DT90

[days] R

2 Chi2

 error 

[%] Kineticsa

1.2 4.1 0.981 15.4 SFO ‘Laacherhof AIIIa’ 

1.1 8.8 nc 3.7 DFOPb

2.9 9.6 0.990 9.9 SFO 

288 

‘Molino’ 

2.2 13.6 nc 1.5 DFOPb

a

 For modelling purposes 0-DAT values were set to 100.0 

b

 DFOP kinetics data not stated in the study report, calculated by the reviewer 

Conclusion:

The outdoor metabolism study in two semi-disturbed soils (which were already used within the laboratory 

degradation study) was conducted as supportive study. The purpose of this study was to test the 

degradation pattern of spirotetramat under more natural conditions. Further, the formulated radiolabelled 

spirotetramat was used (volume sprayed onto the soil surface). It was shown that spirotetramat was quickly 

degraded. Following simple first order kinetics (SFO), calculated DT50 values were 1.2 and 2.9 days for 

‘Laacherhof AIIIa’ and ‘Molino’ soil, respectively. Following best-fit kinetics (DFOP), DT50 values were 1.1 

and 2.2 days, respectively, with DT90 values of 8.8 and 13.6 days. A conservative estimate of first-order halflives for spirotetramat calculated from the best-fit kinetics (i.e. DFOP-DT90 divided by 3.32) yielded 2.7 and 

4.1 days, respectively. Release of CO2 was not measurable since the study was designed as ‘open outdoor’ 

study. Mineralization could only be addressed by calculation of the losses of radioactivity (including possible 

translocation of radioactivity into deeper soil layers whereas no drainage water was obtained during the 

study). Within the study > 75 % of AR was lost until study termination (DAT-127). The NER fraction 

increased up to 13.2 % and 16.8 % of AR in the two soils by DAT-28 and by DAT-63, respectively. Beside a 

large number of minor non-identified degradates (none exceeding 2.1 % of AR individually), one major 

metabolite was detected: spirotetramat-ketohydroxy (max. 25.3 % of AR by DAT-14). Spirotetramat-enol was 

detected with amounts > 5 % of AR at two successive DATs in ‘Molino’ soil (max. 7.8 % of AR by DAT-7).

Degradates as spirotetramat-MA-amide, dimethyl-benzoic acid, spirotetramat-glyoxylic-amide, spirotetramatenol-dimer 1, spirotetramat-enol-dimer 2 and spirotetramat-ketohydroxy-carboxy were identified as minor 

degradates. In comparison to the laboratory degradation study three new metabolites were identified within 

this study: spirotetramat-glyoxylic amide, dimethyl-benzoic acid and spirotetramat-ketohydroxy-carboxy, 

whereas the first two also were identified within the laboratory photolysis study and now confirmed to occur 

under outdoor conditions as well. Further it has to be concluded that the formation of the spirotetramat-enoldimers within the outdoor study with another application technique (broadcast application) was about < 1.5 % 

of AR. 

Reviewer comments: 

• Study will be used as additional information, only. 

• The considerable lower formation of NER is in strong contrast to findings in the parent lab study and

the spirotetramat-enol study. For this reason a statement was requested by the reviewer. 

Notifier’s (BCS) response (position paper Hellpointner et al., 2007): 

Several reasons are expected to lead to reduced NER formation in the 14C-parent outdoor study 

as compared to the parent lab aerobic soil study: 

In the lab studies sieved soils (2 mm particle size) were used in contrast to semi disturbed (nonsieved, stamped) soils in the outdoor study. As a consequence, lab soil samples consist of 

particles with exaggerated surface area on the top and in the upper soil layer compared to the 

outdoor soils with reduced surface area particles. This will lead to an increased likelihood of 

applied test item to react with soil surface components (chemisorption) in the lab study. Slightly 

mechanical soil mixing after application in the lab study is expected to increase this tendency in 
– 24 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

contrast to the outdoor soils treated with formulated test item, but untreated mechanically 

afterwards. 

More surface-located test item in combination with improved outdoor biomass conditions and 

increased outdoor aerobicity would be expected to result in increased enol degradation 

(oxidation), ketohydroxy formation and finally higher mineralization. The latter is expected to be 

the reason for the increasing radioactivity balance gaps of this non-balance outdoor study 

towards the study end. 

The described processes are not expected at all to lead to increasing metabolite leaching 

potential but rather to an increased mineralization from the top soil. This is in line with the 

results from the US terrestrial field dissipation studies were no leaching potential of the soil 

analytes was observed (parent, enol, ketohydroxy, MA-amide). 
– 25 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Reference: [Azaspirodecenyl-3-14C]- and [Azaspirodecenyl-5-14C]-Labelled BYI08330-cisEnol: Comparative Aerobic Soil Metabolism/Degradation in Four Soils 

Author(s), year: Babczinski, P., 2006b 

Study/report number: M-269304-01-2, MEF-05/157 

Guideline(s): EC-Directive 91/414/EEC Annex I Part 7 and Annex II Part 9, 

OECD Guideline 307, 

EPA-Guidelines for Aerobic Soil Metabolism Studies, § 162-1, 

Japanese MAFF Guidelines 

GLP: Yes 

Deviations: None 

Validity: Study considered acceptable 

Purpose of study:

In the aerobic metabolism/degradation study with spirotetramat it was not possible to determine the kinetics 

of all degradates since the main degradate spirotetramat-enol showed a partial instability under the acidic 

extraction/processing conditions required for spirotetramat stability. Further it was assumed that irregular 

spirotetramat-enol levels due to artifactual high spirotetramat-enol-dimer formation (caused by “hot spot” 

application technique) did not allow for adequate degradate kinetic evaluations. Therefore, this separate 

spirotetramat-enol metabolism/degradation study was performed. 

Material and methods:

Test substance: • [Azaspirodecenyl-3-14C]-spirotetramat-enol: sample ID: BECH 00992; 

specific activity 4.54 MBq mg-1 (122.8 μCi mg-1); radiochemical purity: 

> 99 % (acc. radio-HPLC and -TLC), identity and purity of the stock 

solutions were checked 

• [Azaspiro-decenyl-5-14C]-spirotetramat-enol: sample ID: BECH 00995; 

specific activity 4.99 MBq mg-1 (134.94 μCi mg-1); radiochemical purity: 

> 99 % (acc. radio-HPLC and -TLC), identity and purity of the stock 

solutions were checked 

Reference substances: Spirotetramat-enol (unlabelled), spirotetramat-ketohydroxy, spirotetramat-MAamide, spirotetramat-enol-dimer 1 

Test system: Static incubation test system 

Test conditions: Study was performed in static incubation test systems under aerobic conditions in 

the dark at 20 ± 1 °C. Moisture adjustment after application to either 60 % MWHC 

(EU soils) or approx. 80 % of 1/3 bar moisture (US soil). At DAT-4 the absolute 

microbial biomass carbon contents corresponded to 4.7, 6.0, 2.7 and 1.3 % 

relative to the soil organic carbon content of the soils ‘Hoefchen’, ‘Laacherhof 

AXXa’, ‘Laacherhof AIII’ and ‘Molino’, respectively. 

For all four soils and all sampling intervals, the two test flasks containing the soils 

treated with the two differently labelled test items were considered as replicates. 

In addition, for DAT-0 samples separate replicates were set up with the [5-14C] 

labelled test item. 

Test duration: 119 days; sampling intervals: 0, 0.25, 1 ,4, 7, 14, 32, 60, 90 and 119 days 

Application: A higher volume (7.4 to 11 mL) of aqueous application solution for the treatments 

were used considering that the application technique might have an influence on 

the metabolic pattern (see Babczinski, P., 2005) 

US soil – actual rate of [3-14C]-spirotetramat-enol applied was 53.5 kBq flask-1

, 

corresponding to 118 μg kg-1 soil (DM); actual rate of [5-14C]-spirotetramat-enol 

applied was 62.9 kBq flask-1 corresponding to 126 μg kg-1 soil (DM), respectively. 
– 26 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

EU soils – actual rate of [3-14C]-spirotetramat-enol applied was 133.8 kBq flask-1, 

corresponding to 295 μg kg-1 soil (DM); actual rate of [5-14C]-spirotetramat-enol 

applied was 139.9 kBq flask-1, corresponding to 280 μg kg-1 soil (DM), 

respectively. 

The calculations were based on homogeneous distribution in 15 cm depth of US 

soil, and in 2.5 cm depth of EU soils. 

Analyses: Aqueous extraction method: 100 g dry (DM) soil samples of each sampling 

interval were extracted once with 80 mL of water containing 0.025 % NH3 at room 

temperature (aqueous ammonia, resulting in pH values of approx. 7.0 to 8.5). 

Ambient extraction procedure: The residual soil after aqueous extraction was 

extracted three times with 80 mL of acetonitrile/water (1:1, containing 0.1 % 

ammonium chloride [w/v] and 0.06 % ammonia [v/v]; pH approx. 8.5) by shaking 

at room temperature. 

Aggressive extraction procedure: This was followed by an “aggressive” microwave 

extraction at 70 °C (10 min) using the same medium as for the conventional 

extractions. 

The spirotetramat-enol residues were radio-assayed by LSC and analyzed 

separately in the aqueous extract, the combined ambient extracts and the 

“aggressive” extract by reversed phase (C-18) HPLC. Solid samples (i.e. soil and 

paper filters) were combusted and 14C levels were measured using LSC. For 

identification of test item and transformation products, co-chromatography and 

spectrometric methods were used. 

Volatile traps: Trap attachment (permeable for oxygen) containing soda lime for absorption of 

14CO2 and a polyurethane foam plug for adsorption of volatile organic compounds 

(identification of 14C as 14CO2 by BaCO3 precipation) 

Analytical techniques: LSC, RP-HPLC, Si-60 silica TLC, LC-MS 

Detection limits: LSC: LOQ ≤ 0.2 % of AR, for CO2 samples LOQ < 0.1 % of AR; HPLC: LOQ ≤

0.3 % of AR. 

Kinetic evaluation: Best fit kinetic model: SFO, FOMC and DFOP; MatLAB, vers. 7.0.4.365; LOD was 

set to 0.1 % of AR; values below the LOD were reported as < 0.1 % of AR. 
– 27 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.1.1-11: Main soil properties. 

Parameter ‘Molino’ ‘Laacherhof 

AXXa’ 

‘Laacherhof 

AIII’ ‘Hoefchen’ 

Source Florida, 

USA 

Monheim, 

Germany 

Monheim, 

Germany 

Burscheid, 

Germany 

Texture (USDA) Sandy loam Sandy loam Silt loam Silt 

Soil taxonomic classification (USDA) 

Fine-loamy, 

kaolinithic, 

thermic 

Plinthic 

Kandiudults 

Sandy, mixed, 

mesic Typic 

Cambudolls 

Loamy, mixed, 

mesic Typic 

Argudalfs 

Loamy, mixed, 

mesic Typic 

Argudalfs 

SCS soil series Ultisol Mollisols, 

Udolls Alfisols, Udalfs Alfisols, Udalfs

Sand (USDA) [%] 77.3 72.4 36.9 8.5 

Silt (USDA) [%] 12.7 22.6 51.1 81.3 

Clay (USDA) [%] 10.0 5.0 12.0 10.2 

pH (H2O) 6.1 7.2 7.4 7.6 

pH (CaCl2) 5.4 6.3 6.5 6.7 

pH (KCl) nd 6.4 nd 7.0 

Organic matter [%] 1.60 1.75 1.43 3.63 

Organic carbona [%] 0.93 1.02 0.83 2.11 

Carbonate (CaCO3) [%] < 0.1 < 0.1 < 0.1 0.9 

CEC [meq/100 g DM] 6 8 8 15 

WHC at pF2.5 (FC at 0.33 bar) [g/100 g DM] 18.4 29.1 20.7 35.6 

MWHC [g/100 g DM] Not available 34.4 36.4 63.1 

Microbial Cb [mg microbial C/kg DM] 21 days 

before application 103 627 363 1012 

Microbial Cb [mg microbial C/kg DM] DAT-4 118 613 226 1001 

Microbial Cb [mg microbial C/kg DM] DAT-62 

native: 88 

with solvent: 

78 

native: 478 

with solvent: 

422 

native: 159 

with solvent: 

184 

native: 686 

with solvent: 

712 

Microbial Cb [mg microbial C/kg DM] DAT-119 

native: 55 

with solvent: 

55 

native: 366 

with solvent: 

374 

native: 123 

with solvent: 

77 

native: 572 

with solvent: 

565 

nd denotes not determined 

a

 Organic C = organic matter / 1.724 

b

 Substrate induced respiration 

Findings:

The DAT-0 recovery showed that for the ‘Molino’ and ‘Laacherhof AIII’ soils the extraction efficacy ranged 

between 92.0 % and 103.2 %, 4.2 % to 9.3 % of AR were still bound on the soil matrix. For the ‘Laacherhof 

AXXa’ and ‘Hoefchen’ soils 23.4 % to 28.4 % of AR was recovered as bound residues and only 76.0 % to 

77.6 % of AR were extractable. It was shown that the degradation of spirotetramat-enol was found to be

ongoing during sample processing, starting with the aqueous extraction. Already immediately after 

application (1 – 2 minutes) spirotetramat-enol oxidation was leading to spirotetramat-ketohydroxy. 

The material balance ranged from 84.8 % to 108.4 % of AR (both labels), with three out of 80 values ranged 

below 90 % at 84.8 %, 88.9 % and 89.2 %; one flask was at 76.4 % most probably due to volatile leakage

and was rejected. 

At study termination the amount of 14CO2 accounted for 16.7 % to 27.8 % of AR when using the [5-14C] 

labelled test item. Higher mineralization levels were expected with the [3-14C] test item accounting for 28.2 % 

to 43.0 % of AR until DAT-119. No volatile organics were evolved from the systems. 

The non-extractable residues (NER) ranged from 4.2 % to 28.4 % of AR ([5-14C] label) and from 8.7 % to 

23.8 % of AR ([3-14C] label) at DAT-0, respectively and increased immediately up to 47.6 % - 59.6 % of AR 
– 28 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

except of ‘Laacherhof AIII’ soil (NER 27.9 / 26.1 % of AR) at DAT-0.25. At the termination of the studies 

bound residues reached a level of 44.8 % to 62.5 % of AR (both labels). The non-extractable 14C-residues 

were lower in the [3-14C] label experiments as compared to the [5-14C] label. The same trend was shown by 

the extractable residues. A partitioning of the heterogeneous NER radioactivity into humic acid, fulvic acid 

and humin like fractions was observed, with generally a major portion of radioactivity in the fulvic acid fraction 

at later sampling intervals and with a significant portion still remaining bound to the soil in the insoluble humin 

fraction. 

Using the aqueous extraction step prior to the conventional organic/aqueous extraction a significant part of 

AR could only be dissolved at the very early DAT (despite a solubility of 78 mg spirotetramat-enol per litre of 

water). Extractable 14C residues were > 90 % of AR at DAT-0 for soils ‘Molino’ and ‘Laacherhof AIII’ and 

between 76.0 % and 77.6 % of AR for soils ‘Laacherhof AXXa’ and ‘Hoefchen’. A decrease to < 25 % of AR

in all four soils was observed, ranging from 9.2 % of AR (soil ‘Hoefchen’, [5-14C] label) to 24.7 % of AR (soil 

‘Molino’, [3-14C] label) at study termination. 

During the study a great number of radioactive peaks were detected and quantified. Under unidentified 

radioactivity all minor peaks plus diffuse radioactivity was summed up. In the Table B.8.1.1.1-14 all 

components are given as mean values (except of the unidentified) whereas the two labels were considered 

as duplicates. This was only applicable where the respective component still carried both labels within the 

molecule. 

The test item spirotetramat-enol showed a biphasic decline whereas in the first phase a very fast degradation 

was observed (in three soils a degradation of > 80 % of AR within six hours). This phase was matched by a 

rapid appearance of the major degradation product spirotetramat-ketohydroxy. The main metabolite 

spirotetramat-ketohydroxy accounted for max. 24 % of AR at DAT-1 in soil ‘Laacherhof AIII’. The 

spirotetramat-enol-dimer 1 (max. 5 % of AR at DAT-60) amounted once to 5 % of AR in one soil and 

spirotetramat-enol-dimer 2 did not reach the 5 % during the study. Spirotetramat-MA-amide amounted 

once > 5 % of AR (5.2 % of AR at DAT-4). Two further minor metabolites and spirotetramat-desmethylenol (max. 2 % of AR at DAT-4) were identified. In addition, as a previously unknown metabolite, 

spirotetramat-oxo-ketohydroxy (<< 0.5 % of AR), was identified. 

A correlation between the biomass content and the decline of spirotetramat-enol and the formation of 

spirotetramat-ketohydroxy and spirotetramat-MA-amide seems to exist. Further, no correlation was found

between decline of spirotetramat-enol and the pH value of the soil. 

Owing to the visual inspection and the statistical results (chi2 error, R2

) the SFO model was not the 

appropriate kinetic model for this substance. In a second step the bi-phasic model FOMC (First-order multi 

compartment) according to Gustafson-Holden showed much better results. But the most appropriate model 

was the DFOP model (double first order in parallel). The calculated DT50 values using the DFOP model 

ranged from 0.02 – 0.2 days. The respective DT90 values were in a range from 22.9 – 106.9 days. A 

recalculation of the degradation kinetic of spirotetramat-enol was conducted (see point B.8.1.2.3, Röpke, 

2006a). 

The degradation behaviour of the metabolites spirotetramat-ketohydroxy and spirotetramat-MA-amide was 

recalculated by a separate study (B.8.1.2.3, Röpke, 2006a). 

The minor metabolite spirotetramat-desmethyl-enol and the minor “metabolites” spirotetramat-enol-dimer 1 

and 2 were not considered kinetically. 
– 29 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Metabolic pathway 

The degradation pathway of spirotetramat-enol confirms the pathway already explained in the spirotetramat 

metabolism study. In the major pathway the spirotetramat-enol will be oxidized at the benzylic carbon 

position into spirotetramat-ketohydroxy which is hydrolytically opened into the spirotetramat-MA-amide and 

finally mineralized into CO2. In a second (minor) pathway, demethylation of the spirotetramat-enol into 

spirotetramat-desmethyl-enol is followed by entire mineralization to CO2. In a third (minor) pathway 

spirotetramat-ketohydroxy is demethylated leading to the spirotetramat-desmethyl-ketohydroxy and merging 

into spirotetramat-oxo-ketohydroxy by oxidation followed by mineralization to CO2. In a fourth degradation 

pathway the spirotetramat-enol-dimer 1 and spirotetramat-enol-dimer 2 were pretended to be built through 

oxidative enol dimerization, but this pathway is regarded as non relevant under environmental conditions 

(artifactual character). These results were included in the proposed overall metabolic pathway of 

spirotetramat in soil (see Figure B.8.1.1.4-1). 
– 30 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.1.1-12: Distribution and recovery of applied radioactivity [% of AR] after application of 

[3-14C] and [5-14C] labelled spirotetramat-enol to four soils incubated under aerobic conditions. 

Total Extracted NER CO2 Total Soil DAT 

[5-14C] [3-14C] [5-14C] [3-14C] [5-14C] [3-14C] [5-14C] [3-14C] 

0 92.0 99.7 9.3 8.7 na na 101.3 108.4 

0.25 50.3 48.6 48.5 50.5 0.5 1.5 99.4 100.6 

1 46.1 49.8 50.7 50.3 1.0 3.3 97.8 103.5 

4 44.0 44.2 50.2 50.3 1.9 6.1 96.1 100.6 

7 45.7 43.7 48.4 46.9 2.8 7.9 96.9 98.5 

14 39.9 41.0 52.6 49.6 4.2 11.2 96.6 101.8 

32 36.8 34.3 52.4 49.4 7.6 17.1 96.8 100.8 

60 31.5 28.2 52.7 49.8 10.9 20.1 95.1 98.1 

90 37.2 33.2 45.2 42.7 14.0 24.8 96.3 100.7 

‘Molino’ 

119 24.7 20.3 55.3 52.3 16.7 28.2 96.8 100.8 

0 76.0 77.6 28.4 23.6 na na 104.4 101.2 

0.25 48.8 50.2 49.7 47.6 0.4 1.3 98.8 99.1 

1 48.9 49.4 50.2 48.5 1.0 3.5 100.1 101.3 

4 46.0 43.8 46.2 51.6 2.4 8.2 94.6 103.6 

7 44.9 41.1 51.1 44.0 3.7 12.3 99.8 97.5 

14 38.9 34.5 52.9 51.1 5.5 17.4 97.3 103.1 

32 33.9 27.9 54.7 47.6 10.2 23.4 98.8 98.9 

60 30.9 24.9 44.9 38.9 13.4 26.5 89.2 90.3 

90 35.9 27.3 36.3 40.8 16.8 31.1 88.9 99.2 

‘Laacherhof 

AXXa’ 

119 22.9 18.5 54.3 45.5 19.0 32.5 96.2 96.5 

0 103.2 99.6 4.2 4.4 na na 107.4 103.9 

0.25 72.0 73.3 27.9 26.1 0.2 0.3 100.2 99.7 

1 57.6 55.8 43.4 40.9 0.8 2.3 101.9 99.1 

4 48.8 48.4 49.6 44.2 2.1 5.8 100.6 98.4 

7 47.3 43.2 50.4 45.7 2.9 9.1 100.6 98.0 

14 38.9 36.2 56.3 45.0 6.0 16.0 101.2 97.2 

32 29.3 24.5 57.8 46.5 11.6 25.8 98.7 96.8 

60 21.4 16.9 58.3 46.6 19.2 34.9 98.9 98.4 

90 21.4 14.6 53.3 43.1 23.4 40.3 98.1 98.0 

‘Laacherhof 

AIII’ 

119 12.8 9.9 57.0 44.8 27.8 43.0 97.5 97.7 

0 77.1 76.0 25.6 23.8 na na 102.7 99.8 

0.25 38.8 40.3 59.6 54.5 0.3 1.5 98.8 96.3 

1 40.0 39.1 57.9 53.3 1.3 5.3 99.2 97.7 

4 33.8 30.1 60.1 52.7 3.8 12.4 97.7 95.1 

7 29.3 24.8 60.9 53.7 5.7 17.1 95.9 95.5 

14 24.6 19.7 59.3 56.7 8.6 8.6 92.6 76.4a

32 20.9 17.1 63.0 52.5 12.6 27.2 96.5 96.7 

60 17.1 12.7 62.0 51.1 17.2 31.9 96.3 95.8 

90 19.8 13.9 44.8 41.3 20.3 35.2 84.8 90.4 

‘Hoefchen’ 

119 11.8 9.2 62.5 51.0 22.0 36.9 96.3 97.1 

a

 Recovery loss caused by flask leakage 
– 31 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.1.1-13: Characterization [% of AR] of non-extractable soil residues (NER). 

Sampling DAT-0 DAT-14 DAT-32a DAT-32a DAT-60 DAT-60 DAT-119 DAT-119 

Soil ‘Hoefchen’ ‘Laacherhof AXXa’ ‘Laacherhof AXXa’ ‘Hoefchen’ ‘Laacherhof AIII’ ‘Laacherhof AIII’ ‘Molino’ ‘Molino’ 

Total NER 49.7 48.0 53.6 62.5 57.7 44.2 54.3 44.1 Fraction humic acids 19.1 18.7 20.9 19.1 9.2 6.2 9.6 9.0 Fraction fulvic acids 19.2 17.4 20.6 28.8 28.0 23.8 35.8 28.0 Fraction humin substances 15.4 10.0 11.7 18.7 19.2 14.6 10.2 8.3 Processing balance [%] 108.0 95.9 99.2 106.6 97.7 101.0 102.3 102.8 a ‘DAT-30’ stated in the original report probably a typo Table B.8.1.1.1-14: Characterization of extractable radioactivity [% of AR] after application of [3-14C] and [5-14C] labelled spirotetramat-enol to four 

soils incubated under aerobic conditions (means of both labels). 

Unidentifieda

Soil DAT Spirotetramat- enol Spirotetramat- Desmethyl-enol Spirotetramat- enol-dimer 1 Spirotetramat- enol-dimer 2 Spirotetramat- ketohydroxy Spirotetramat- MA-Amide [5-14C] [3-14C] 

0 78.0 nd 0.2 nd 11.7 nd 5.4 6.5 

0.25 17.3 0.2 2.5 1.6 17.0 0.9 9.4 10.6 

1 13.4 0.5 1.8 1.7 17.4 1.4 10.9 12.5 4 10.9 1.0 2.9 1.8 15.7 2.4 12.5 6.4 7 14.7 1.1 1.2 1.4 12.0 2.9 14.7 7.9 

14 10.7 0.8 3.4 2.2 8.2 2.9 14.4 10.3 32 7.7 0.9 3.6 1.6 5.4 2.2 16.1 12.2 60 6.1 0.7 2.3 1.3 3.7 1.5 16.6 12.0 90 7.1 0.7 2.3 1.3 3.8 1.3 21.9 15.5 

‘Molino’ 

119 4.8 0.4 1.8 1.8 2.5 0.9 11.4 9.4 

0 53.7 0.2 0.9 nd 13.8 nd 7.2 9.4 

0.25 14.1 0.1 4.0 2.7 16.6 1.3 10.4 10.8 

1 14.7 0.5 2.4 3.0 16.2 2.6 10.9 8.8 4 14.6 1.2 3.5 2.4 9.3 2.7 12.9 9.5 7 17.0 1.6 1.8 2.5 6.0 2.0 13.8 10.5 

14 11.9 0.8 4.4 3.6 3.0 1.4 14.4 8.5 32 8.7 0.4 4.9 2.8 2.2 0.1 14.4 9.0 60 6.7 0.2 5.0 2.3 1.4 0.1 14.2 10.4 90 7.6 0.3 4.1 2.0 1.8 0.2 20.4 10.8 

‘Laacherhof 

AXXa’ 

119 6.1 < LOQ 3.7 3.3 0.5 0.1 7.4 6.5 

‘Laacherhof 0 83.3 nd 0.3 nd 11.2 nd 7.9 5.0 
– 32 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Unidentifieda

Soil DAT Spirotetramat- enol Spirotetramat- Desmethyl-enol Spirotetramat- enol-dimer 1 Spirotetramat- enol-dimer 2 Spirotetramat- ketohydroxy Spirotetramat- MA-Amide [5-14C] [3-14C] 

0.25 38.0 nd 1.4 1.0 22.3 0.9 10.3 7.9 

1 17.2 0.6 0.9 0.9 24.0 1.6 11.0 12.0 4 4.8b 2.0 1.2 1.0 19.8 5.2 16.0 13.4 7 11.6 1.6 0.7 1.2 11.1 4.9 13.8 14.6 

14 7.7 1.5 1.5 1.3 5.7 3.6 18.7 13.7 32 5.7 0.4 1.8 1.3 2.2 0.9 16.0 13.5 60 3.7 0.2 2.0 0.8 1.1 0.1 13.1 9.5 90 4.0 0.1 1.0 0.6 0.9 0.2 14.6 7.9 

AIII’ 

119 2.7 nd 1.0 1.2 0.6 0.2 6.3 4.9 

0 51.6 nd nd nd 18.4 nd 5.9 7.1 

0.25 10.7 0.6 1.6 1.2 15.7 1.5 8.9 7.5 

1 10.5 1.3 1.1 1.4 13.3 2.5 8.2 10.7 4 12.0 1.3 1.8 1.7 4.4 1.8 10.7 7.3 7 11.8 1.0 0.9 1.5 1.9 0.7 10.4 7.9 

14 8.6 0.2 1.8 1.6 1.3 0.3 9.5 7.1 32 6.3 0.2 1.9 0.9 1.4 0.2 9.8 6.2 60 4.6 < 0.1 2.1 0.9 0.5 nd 9.2 4.3 90 6.0 0.1 1.0 0.6 0.6 0.1 10.8 6.3 

‘Hoefchen’ 

119 3.8 nd 1.1 1.4 0.3 nd 4.6 3.3 

nd denotes not determined a Total % of AR for unidentified discrete components and streaking, none exceeding > 4.9 % of AR individually b Spirotetramat-enol Dat-4 value was considered as outlier 
– 33 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.1.1-15: Characterization of extractable radioactivity [% of AR] after application of [3-14C] and [5-14C] labelled spirotetramat-enol to four 

soils incubated under aerobic conditions (individual values for each label). 

Spirotetramatenol Spirotetramat- Desmethyl-enol Spirotetramat- enol-dimer 1 Spirotetramat- enol-dimer 2 Spirotetramat- ketohydroxy Spirotetramat- MA-Amide Unidentifieda Soil DAT 

[5-14C] [3-14C] [5-14C] [3-14C] [5-14C] [3-14C] [5-14C] [3-14C] [5-14C] [3-14C] [5-14C] [3-14C] [5-14C] [3-14C]

0 76.2 79.7 nd nd nd 0.5 nd nd 10.3 13.0 nd nd 5.4 6.5 

0.25 18.7 15.8 nd 0.4 3.2 1.7 2.2 0.9 16.1 17.9 0.6 1.2 9.4 10.6 

1 13.3 13.5 0.4 0.6 1.8 1.8 1.9 1.5 16.9 18.0 1.0 1.9 10.9 12.5 4 9.2 12.5 0.7 1.3 3.6 2.3 2.2 1.4 14.0 17.3 1.8 3.0 12.5 6.4 7 14.0 15.5 0.6 1.6 1.4 1.0 1.5 1.4 11.1 12.9 2.3 3.5 14.7 7.9 

14 10.3 11.1 0.3 1.2 3.2 3.6 2.2 2.1 6.9 9.4 2.5 3.3 14.4 10.3 32 7.3 8.2 0.7 1.0 3.5 3.7 1.7 1.6 5.3 5.5 2.2 2.2 16.1 12.2 60 5.8 6.3 1.0 0.5 2.1 2.5 1.5 1.1 3.1 4.3 1.4 1.6 16.6 12.0 90 6.7 7.5 0.8 0.5 2.2 2.4 1.3 1.4 3.3 4.3 1.0 1.6 21.9 15.5 

‘Molino’ 

119 4.7 4.9 0.3 0.5 2.1 1.4 2.5 1.1 2.6 2.4 1.2 0.6 11.4 9.4 

0 55.0 52.3 nd 0.3 0.7 1 nd nd 13.1 14.6 nd nd 7.2 9.4 

0.25 14.4 13.8 nd 0.3 4.3 3.8 3.4 2.1 15.4 17.8 0.9 1.7 10.4 10.8 

1 13.3 16.1 0.5 0.5 2.6 2.2 3.2 2.8 16.4 15.9 2.1 3.1 10.9 8.8 4 15.0 14.3 0.9 1.5 3.7 3.3 2.8 2.1 8.5 10.1 2.3 3.1 12.9 9.5 7 17.9 16.1 1.3 1.9 1.9 1.7 2.7 2.3 5.6 6.4 1.7 2.2 13.8 10.5 

14 11.7 12.0 0.8 0.8 4.4 4.5 3.6 3.7 2.7 3.4 1.2 1.7 14.4 8.5 32 8.4 9.0 0.3 0.6 5.5 4.4 3.2 2.5 2.0 2.4 0.1 0.2 14.4 9.0 60 6.5 6.9 0.3 0.1 5.7 4.2 2.8 1.7 1.2 1.6 0.1 nd 14.2 10.4 90 6.9 8.2 nd 0.5 4.0 4.3 2.2 1.8 2.2 1.4 0.2 0.2 20.4 10.8 

‘Laacherhof 

AXXa’ 

119 6.6 5.6 <LOQ nd 4.4 3.1 3.9 2.7 0.7 0.4 nd 0.2 7.4 6.5 

0 86.1 80.6 nd nd 0.6 nd nd nd 8.5 13.9 nd nd 7.9 5.0 

0.25 38.8 37.2 nd nd 1.6 1.1 1.2 0.8 19.4 25.2 0.6 1.1 10.3 7.9 

1 18.9 15.5 0.7 0.5 1.1 0.8 1.0 0.9 23.5 24.4 1.4 1.8 11.0 12.0 4 3.5b 6.0b 2.0 2.0 1.2 1.1 1.2 0.9 19.7 19.9 5.3 5.0 16.0 13.4 7 12.9 10.2 1.2 1.9 0.8 0.6 1.5 0.9 12.0 10.3 5.2 4.7 13.8 14.6 

14 7.7 7.8 1.2 1.8 1.7 1.4 1.3 1.2 5.2 6.3 3.1 4.0 18.7 13.7 32 6.1 5.3 0.3 0.5 2.2 1.4 1.6 0.9 2.3 2.1 0.8 0.9 16.0 13.5 60 4.1 3.2 0.2 0.2 2.1 1.9 0.8 0.8 1.1 1.1 nd 0.3 13.1 9.5 90 4.3 3.6 nd 0.1 1.1 0.9 0.5 0.6 0.8 0.9 nd 0.5 14.6 7.9 

‘Laacherhof 

AIII’ 

119 3.0 2.5 nd nd 1.3 0.8 1.4 1.0 0.5 0.6 0.2 0.2 6.3 4.9 

‘Hoefchen’ 0 53.8 49.3 nd nd nd nd nd nd 17.3 19.6 nd nd 5.9 7.1 
– 34 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Spirotetramatenol Spirotetramat- Desmethyl-enol Spirotetramat- enol-dimer 1 Spirotetramat- enol-dimer 2 Spirotetramat- ketohydroxy Spirotetramat- MA-Amide Unidentifieda Soil DAT 

[5-14C] [3-14C] [5-14C] [3-14C] [5-14C] [3-14C] [5-14C] [3-14C] [5-14C] [3-14C] [5-14C] [3-14C] [5-14C] [3-14C]

0.25 10.8 10.6 0.4 0.7 1.7 1.4 1.1 1.3 14.8 16.6 1.0 2.1 8.9 7.5 

1 13.7 7.3 1.3 1.3 1.2 1.1 1.5 1.3 11.9 14.8 2.3 2.7 8.2 10.7 4 12.4 11.6 1.4 1.1 1.9 1.7 1.7 1.8 4.1 4.7 1.7 1.9 10.7 7.3 7 12.9 10.8 0.9 1.0 0.9 0.8 1.5 1.6 2.0 1.9 0.7 0.8 10.4 7.9 

14 8.8 8.5 0.5 nd 2.0 1.6 2.0 1.2 1.4 1.2 0.4 0.1 9.5 7.1 32 6.5 6.1 0.2 0.3 2.0 1.8 0.8 1.1 1.4 1.4 0.1 0.2 9.8 6.2 60 4.8 4.4 nd 0.1 2.0 2.3 0.8 1.0 0.4 0.6 nd <LOQ 9.2 4.3 90 6.3 5.8 0.2 <LOQ 0.9 1.0 0.7 0.5 0.8 0.3 0.1 nd 10.8 6.3 

119 4.1 3.5 nd nd 1.2 1.0 1.6 1.1 0.3 0.3 nd nd 4.6 3.3

nd denotes not determined a Total % of AR for unidentified discrete components and streaking, none exceeding > 4.9 % of AR individually b Spirotetramat-enol Dat-4 value was considered as outlier 
– 35 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.1.1-16: Calculated DT50 and DT90 values [days] of spirotetramat-enol in four aerobic soils 

based on DFOP kinetics (best fit kinetics). 

Soil DT50 [days] DT90 [days] R2 Chi2 error Kinetics 

‘Molino’ 0.09 53.7 0.996 6.9 DFOP 

‘Laacherhof AXXa’ 0.02 106.9 0.987 8.7 DFOP 

‘Laacherhof AIII’ 0.20 22.9 0.996 7.2 DFOP 

‘Hoefchen’ 0.02 74.0 0.993 8.1 DFOP 

Conclusion:

Spirotetramat-enol ([3-14C] and [5-14C] labelled), the major degradate of spirotetramat, dissipates in soil 

following biphasic kinetics (best fit) and is thoroughly mineralized. The calculated DT50 values ranged from 

0.02 – 0.20 days (DFOP kinetics), respective DT90 values were in a range of 22.9 – 106.9 days. A positive 

correlation of the spirotetramat-enol dissipation and the formation of soil degradates with the soil biomass 

was partly evident. No correlation was found between spirotetramat-enol dissipation and the soil pH values. 

At study termination the evolved 14CO2 (no volatile organics) was about 16.7 % to 27.8 % of AR ([5-14C] 

labelled test item) and about 28.2 % to 43.0 % of AR ([3-14C] labelled test item), respectively. Up to > 50 % of 

AR was detected in the NER fraction at DAT-1 and reached a level of 44.8 % to 62.5 % of AR (both labels) at 

DAT-119. Extractable residues decreased from > 90 % of AR at DAT-0 to a minimum of 9.2 % of AR at study 

termination. 

Besides the test item spirotetramat-enol, spirotetramat-ketohydroxy, spirotetramat-enol-dimer 1, 

spirotetramat-enol-dimer 2, spirotetramat-MA-amide, spirotetramat-desmethyl-enol and spirotetramat-oxoketohydroxy were identified. In all four soils, spirotetramat-ketohydroxy was identified as major metabolite 

(> 10 % of AR) with amounts up to 24 % of AR (DAT-1). All other degradates, with the exception of 

spirotetramat-MA-amide, were ≤ 5 % of AR (minor). No label-specific degradates were observed throughout 

the entire study. 

Reviewer comments:

• Labels were handled as replicates. Additional calculations by the reviewer confirmed that the 

degradation of both labels is almost identical. Therefore the usage of a mean value is considered 

acceptable. 

• The degradation behaviour of spirotetramat-enol, spirotetramat-ketohydroxy and spirotetramat-MAamide was investigated in a separate kinetic analysis study (see B.8.1.2.3, Röpke, 2006a). 
– 36 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

B.8.1.1.2 Anaerobic degradation in soil (OECD Annex IIA, 7.1.2) 

The route of anaerobic degradation (metabolism) of spirotetramat in soil was investigated in one study (also 

used for anaerobic degradation rate calculation): 

• Aerobic/anaerobic degradation in one soil (20 °C, [3-14C] label) 

Reference: BYI08330: Anaerobic Soil Metabolism 

Author(s), year: Menke, U., 2006a 

Study/report number: M-270739-01-2, MEF-05/515 

Guideline(s): OECD Guideline for Testing of Chemicals, Guideline 307, Aerobic and Anaerobic 

Transformation in Soil, Adopted Document; US EPA Subdivision N, Section 162-

2; CAN PMRA DACO 8.2.3.4.4; Japanese MAFF New Test Guidelines for 

Supporting Registration of Chemical Pesticides, 12 Nohsan 8147 

GLP: Yes 

Deviations: None 

Validity: Study considered acceptable 

Material and methods:

Test substances: [Azaspirodecenyl-3-14C]-spirotetramat; sample ID: BECH 0755; Specific activity 

3.71 MBq mg-1 (100.2 μCi mg-1); radiochemical purity: > 99 % (acc. Radio-HPLC 

and –TLC) 

Reference substances: Spirotetramat (unlabelled), spirotetramat-enol, spirotetramat-ketohydroxy, 

spirotetramat-MA-amide, spirotetramat-di-hydroxy, spirotetramat-oxo-enol, 

spirotetramat-enol-dimer 1 

Test system: Static incubation test system 

Test conditions: The study was performed for approximately one half-life of test item under 

aerobic conditions in the dark at 20 ± 1 °C. Thereby, the test system consisted of 

Erlenmeyer flasks (300 mL) attached with a trap attachment (permeable for 

oxygen) containing soda lime for absorption of 14CO2 and a polyurethane foam 

plug for adsorption of volatile organic compounds. Moisture adjustment after 

application to 50% of maximum water holding capacity was carried out for each 

individual flask by addition of de-ionized water. 

Following the aerobic incubation phase (just 4.8 hours), the samples were 

flooded with oxygen-depleted de-ionized water (3 cm layer above soil level), set 

under nitrogen atmosphere, and maintained in the dark under anaerobic 

conditions for 180 days at 20 °C. At start of the anaerobic study phase, the trap 

systems were replaced by sealable two-valve glass stoppers connected with 

plastic gas sampling bags, closing the flasks to maintain their nitrogen 

atmosphere. 

Test duration: After 4.8 hours aerobic incubation phase 180 days under anaerobic conditions 

Sampling intervals: Duplicate test flasks were processed for analysis after 4.8 hours of aerobic 

incubation, and at 0, 0.6, 1, 4, 6, 14, 32, 60, 90, 120 and 180 days after flooding 

the test systems (anaerobic incubation). 

Application: [3-14C]-spirotetramat was applied at an actual rate of 80.43 μg 100 g-1 soil DM 

(intended nominal concentration of 76.8 μg per flask). This rate was equivalent to 

105 % of the intended maximum field application rate of 288 g ha-1 (assuming a 

homogeneous distribution in 2.5 cm topsoil layer). 

Analyses: Aerobic incubation: soils and traps were removed and subjected for extraction 

and analysis 
– 37 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Anaerobic incubation: Firstly, flasks were connected to the volatiles combustion 

oven. After opening the flasks the water layers were measured for pH, redox 

potential and dissolved oxygen content. 30 mL of the water layer was removed 

for CO2 analysis and the rest were separated from the soil layers by decanting 

and centrifugation and subjected to analysis. 

The soil (aerobic and anaerobic) was extracted twice with 80 mL of 

acetonitrile/water/formic acid (50:50:0.5, v/v/v) followed by an extraction with 1 x 

80 mL acetonitrile. After the organic extraction procedure an acid extraction with 

twice of 80 mL of acetonitrile/1 M HCl (1:1, v/v) followed. Organic and acid 

extracts were kept separate for individual chromatography profiling. Volume and 

radioactivity were determined by LSC. Extracted soils and paper filters were 

combusted and 14C levels were measured using LSC. 

Volatile compounds (contained in the PU foam plugs) were extracted with 25 mL 

of ethyl acetate and radio-assayed by LSC. 

CO2 absorbed by soda lime was liberated with HCl and purged into LS cocktails 

with nitrogen and subjected to LSC. 

Volatile traps: Aerobic phase: Organic volatiles: polyurethane (PU) foam, CO2: soda lime. 

Anaerobic phase: Test system was closed with gas sampling bags, which 

allowed for analysis of the gaseous headspace formed upon anaerobic 

incubation. 

Analytical techniques: LSC, RP-HPLC (C18), TLC, LC-MS, LC-MS/MS, NMR 

Detection limits: LSC: liquid samples LOQ ≤ 0.73 Bq, for CO2 samples LOQ ≤ 1.03 Bq; HPLC: 

LOQ ≤ 0.19 % of AR (9.26 Bq), LOD = 0.06 % of AR (1/3 of LOQ) 

Kinetic evaluation: SFO, FOMC and DFOP kinetics; MatLab 7.0.4.365., C0 calculated by the model; 

used criterion for best fit model kinetic (to derive endpoints): chi2 scaled error and 

visual assessment of the goodness of fit 

Table B.8.1.1.2-1: Main soil properties. 

Parameter ‘Laacherhof AIII’ 

Source Monheim, Germany 

Texture (USDA) Sandy loam 

Soil taxonomic classification (USDA) Loamy, mixed, mesic Typic Argudalfs 

SCS soil series na 

Sand (USDA) [%] 52.45 

Silt (USDA) [%] 30.90 

Clay (USDA) [%] 16.65 

pH (H2O) 7.4 

pH (CaCl2) 6.8 

pH (KCl) 6.9 

Organic matter [%] 0.69 

Organic carbona [%] 0.4 

CEC [meq/100 g DM] 4.8 

WHC at 0.33 bar (1/3 bar WHC) [g/100 g DM] 15.5 

MWHC [g/100 g DM] 36.4 

Microbial Biomass See remarksb

na denotes not available 

a

 Organic C = organic matter / 1.724 

b

 Measurement of initial soil biomass (638 mg microbial C kg-1 soil DM) indicated that the soil was aerobic viable at the beginning of the 

study (treated with test item). Anaerobic bacteria plate count tests indicated that the soil was anaerobic viable throughout the 

anaerobic incubation phase. 
– 38 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Findings:

Verification of the extraction and chromatographic procedures indicated that the chosen extraction method 

was well suitable and the recovery values of the HPLC method were in an acceptable range (101.8, 99.9 and 

98.9 %). 

The material balance ranged from 95.6 to 102.8 % (mean 99.3 % ± 1.7 %). 

The forming of 14CO2 during the aerobic incubation was rather low accounted for max. 0.1 % of AR. The 

mineralization rate during the anaerobic incubation was in the same range with a maximum of 0.3 % of AR at 

DAT-90 (single value of replicate). Volatile organic compounds were neither observed in the aerobic nor in 

the anaerobic phase (< 0.1 % of AR). 

During the short aerobic incubation phase the NER fraction increased from 1.7 % of AR at test start (DAT-(-

0.2)) to 11.7 % of AR at day of flooding. At DAT-0.6 the amount of non-extractable residues increased to its 

maximum of 17.5 % of AR. At study termination the bound residues accounted for 7.9 % of AR (mean 

values). 

The total radioactivity extractable from soil decreased from DAT-(-0.2) from 99.8 % of AR to 32.1 % of AR at 

study termination. In contrast the total radioactivity extractable from the water layer increased from 24.6 % of 

AR on the day of flooding to an amount of 58.7 % of AR at DAT-180 (mean values). The unidentified 

radioactivity was summed up with the diffuse radioactivity. 

The amount of the test item spirotetramat declined in soil (and entire system) from 95.5 % of AR to < 2 % of 

AR within 7 days. Beside the test item several metabolites were identified. Spirotetramat-enol was identified 

as major metabolite in both layers with a maximum amount of 27.9 % of AR (DAT-1) in soil, 43.0 % of AR

(DAT-180) in the water layer and 54.6 % of AR (DAT-180) in the entire system, respectively. Beside 

spirotetramat-enol, spirotetramat-ketohydroxy was identified as a second major metabolite. The maximum 

amount in soil was measured at the same time as for spirotetramat-enol (max. 15 % of AR, DAT-1). In the 

water layer the maximum was reached with 6.2 % of AR at DAT-60. In the entire system spirotetramatketohydroxy increased from the maximum of 19.3 % of AR (DAT-1) to 7.7 % of AR at the end of the study. In 

addition, the following five degradates were identified. Spirotetramat-MA-amide amounted in soil to levels 

of up to 4.4 % of AR (DAT-1), in the water layer up to 5.0 % of AR (DAT-180) and therefore, in the entire 

system up to 7.2 % of AR at the end of the study. The spirotetramat-enol-dimer 1 reached similar high 

levels of up to 7.0 % of AR (DAT-6) in the entire system. In soil the highest level of up to 6.7 % of AR was 

reached at DAT-6. Spirotetramat-enol-dimer 2 reached its maximum in soil of up to 4.6 % of AR at the end 

of the study. Metabolites spirotetramat-di-hydroxy (max. 3.2 % of AR, DAT-32 and 90 in entire system,

max. 1.8 % of AR, DAT-32 in soil) and spirotetramat-oxo-enol (max. 1.4 % of AR, not listed in table) were 

detected only at minor levels (mean values were given in all cases). Furthermore a metabolite designated 

R30 was detected reaching levels of 8.2 % of AR at DAT-0.6 in soil and 8.3 % of AR in the entire system, but 

did not occur with levels > 5 % of AR at two successive DATs. Attempts to fully elucidate its structure by LCMS, LC-MS/MS and NMR were not successful. From the results of the LC-MS/MS spectrometric analysis it 

was concluded by the notifier that the major component was an unknown enol based compound possibly 

originating from polymeric structures (like the enol-dimers). All values from the entire system are summarized 

in Table B.8.1.1.2-3. 

Largest individual unknown metabolites reached up to 1.8 % of AR in the soil layer and 1.7 % of AR in the 

water layer (single values). 

The detected metabolites were almost identical to those formed upon the aerobic transformation in the 

aerobic metabolism study, except of the minor metabolite spirotetramat-di-hydroxy. Spirotetramat-di-hydroxy 
– 39 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

was also formed in the aerobic aquatic metabolism study. Therefore it can be excluded that this metabolite 

will be specially formed under anaerobic conditions. 

The kinetic analysis was done for the entire system (water and soil layer) during the anaerobic incubation 

phase. Three kinetic models (SFO, FOMC and DFOP) were used to evaluate the best fit model. The FOMC 

model indicated the lowest chi2 error value and the best visual fit (see Table B.8.1.1.2-4). The degradation 

rates of spirotetramat in the total system during the anaerobic phase were calculated to be 0.06 days (DT50) 

and 1.33 days (DT90) with a R2 of 0.993. 

Table B.8.1.1.2-2: Distribution and recovery of applied radioactivity [% of AR] after application of 

[3-14C] labelled spirotetramat under aerobic conditions, then turning to anaerobic conditions (mean 

of duplicate samples). 

Soil DAT Water layer 

Extracted 

(organic, 

acid extract) 

CO2 Volatiles NER Total 

recovery 

-0.2a

na 99.8 na na 1.7 101.5 

0

b

na 85.2 0.1 na 11.7 97.0 

0.6 24.6 56.5 0.1 < 0.1 17.5 98.7 

1 23.1 58.5 0.1 < 0.1 17.2 99.0 

4 33.7 47.4 0.2 < 0.1 16.3 97.6 

6 33.7 50.0 0.2 < 0.1 15.5 99.4 

14 40.0 47.5 0.2 < 0.1 12.4 100.1 

32 48.6 39.7 0.2 < 0.1 12.5 101.0 

60 51.4 36.8 0.2 < 0.1 12.2 100.5 

90 52.6 34.6 0.2 < 0.1 11.6 99.1 

120 55.2 32.9 0.1 < 0.1 10.7 98.9 

‘Laacherhof 

AIII’ 

180 58.7 32.1 0.1 < 0.1 7.9 98.8 

na denotes not applicable 

a

 Aerobic incubation phase (0.2 days) 

b

 Flooding of the test systems 
– 40 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.1.2-3: Characterization of extractable radioactivity [% of AR] after application of [3-14C] labelled spirotetramat to one sandy loam soil 

incubated under aerobic conditions, then turning to anaerobic conditions – entire system (individual replicates). 

Spirotetramat Spiro- tetramat-di- hydroxy Spiro- tetramat-MA- amide Spiro- tetramat-enol Spiro- tetramat- ketohydroxy R30 Spiro- tetramat- enol-dimer 1 Spiro- tetramat- enol-dimer 2 Unidentifieda Soil DAT 

A B A B A B A B A B A B A B A B A B 

-0.2b 94.9 96.2 < LQ < LQ < LQ < LQ 1.5 2.1 0.5 0.5 < LQ < LQ < LQ < LQ < LQ < LQ 2.2 1.8 

0c 55.2 62.8 < LQ < LQ 1.1 0.4 9.1 7.8 11.3 6.9 0.4 0.5 3.6 3.5 0.9 1.0 2.8 3.0 

0.6 8.8 10.1 0.1 0.2 3.6 3.6 27.4 25.9 15.4 17.6 8.3 8.4 7.3 5.2 3.9 1.7 7.0 8.0 

1 8.0 5.5 0.3 0.8 4.3 5.4 32.2 32.8 18.4 20.3 5.3 4.2 4.0 4.2 1.0 0.9 7.4 8.4 4 2.6 3.9 1.5 0.8 3.0 2.9 36.5 39.5 18.0 16.4 1.7 2.3 6.2 7.3 1.2 1.4 7.6 9.5 6 1.9 1.0 0.7 1.2 2.1 2.1 43.2 47.3 15.4 15.8 0.8 0.6 7.8 6.2 2.4 2.3 8.9 7.7 

14 2.1 1.0 2.2 1.9 1.6 1.9 53.5 49.7 12.9 16.3 0.7 0.2 4.0 4.2 2.8 3.4 8.3 8.3 32 1.6 1.4 3.0 3.3 4.1 3.7 40.4 40.4 15.7 16.5 0.4 0.5 3.6 4.2 3.6 4.4 15.1 14.7 60 1.5 1.4 2.3 3.0 4.7 4.3 45.1 48.1 14.4 16.1 0.3 0.2 1.0 0.9 3.2 2.9 14.4 12.6 90 1.0 0.9 2.6 3.9 5.0 5.5 48.7 51.5 12.8 12.3 0.5 0.5 1.0 1.1 3.7 3.1 11.0 9.4 

120 0.9 1.0 3.0 3.3 6.7 6.3 47.9 46.7 11.5 11.5 0.4 0.3 0.6 0.5 4.1 4.0 13.3 14.0 

‘Laacherhof 

AIII’ 

180 < LQ < LQ 2.6 2.8 7.3 7.1 56.0 53.3 7.6 7.7 0.8 0.7 0.2 0.3 3.7 5.6 12.5 13.5 

LQ denotes LOQ a Up to 28 unidentified regions, individual amounts < 1.8 % of AR in the soil and < 1.7 % of AR in the water layer b Aerobic incubation phase (0.2 days) c Flooding of the test systems
– 41 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.1.2-4: Calculated DT50 and DT90 values [days] of spirotetramat in ‘Laacherhof AIII’ soil 

incubated under anaerobic conditions – entire system (SFO, FOMC and DFOP kinetics). 

Soil Compartment DT50 [days] DT90 [days] Chi2 error Kinetics 

0.25 0.83 17.95 SFO 

‘Laacherhof AIII’ 0.06 1.33 5.27 FOMC Entire 

system 

0.22 0.87 9.23 DFOP 

Conclusion:

Under anaerobic conditions spirotetramat declines quickly with DT50 values of < 1 day in the total system. 

The two major metabolites spirotetramat-enol and spirotetramat-ketohydroxy occurred with amounts > 10 % 

of AR in the entire system. Spirotetramat-enol was rather stable during the anaerobic incubation period, 

spirotetramat-ketohydroxy increased to 19.3 % of AR and decreased < 10 % of AR towards DAT-180. 

Spirotetramat-MA-amide reached levels > 5 % of AR towards the end of the study and showed increasing 

tendency. Spirotetramat-enol-dimer 1 reached its maximum during the first 7 days afterwards decreasing to 

0.3 % of AR at the end of the study. The second formed dimer, spirotetramat-enol-dimer 2 increased towards 

the end of the study and reached levels up to 4.6 % of AR. During the incubation period the mineralization 

was rather low. 

The metabolites found in the soil and water layers were almost identical to those identified in the aerobic 

metabolism study and in the abiotic hydrolysis experiments except of spirotetramat-di-hydroxy. 

Spirotetramat-di-hydroxy was formed in the aerobic aquatic metabolism study, therefore it can be concluded 

that this metabolite will not specially occur under anaerobic conditions. The unknown metabolite R30, which 

was not identified by the notifier, is not a relevant metabolite since the measured levels only once exceeded 

the 5 % of AR trigger (EU risk assessment). 

Comment (reviewer):

• CO2 identification was not proven owing to the low amounts formed in this study and the high overall 

recovery. This is accepted by the reviewer. 
– 42 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

B.8.1.1.3 Soil photolysis (OECD Annex IIA, 7.1.3) 

Soil photolysis was investigated in one study: 

• Soil photolysis on one soil, [3-14C] and [5-14C] labelled spirotetramat 

Reference: [Azaspirodecenyl-3-14C]- and [Azaspirodecenyl-5-14C]-BYI08330: 

Phototransformation on Soil 

Author(s), year: Heinemann, O., 2005a 

Study/report number: M-252907-01-2, MEF-04/481 

Guideline(s): Commission Directive 95/36/EC amending Council Directive 91/414/EEC, 1995 

Pesticide Assessment Guidelines, Subdivision N, Environmental Fate, US EPA, 

161-3: Photodegradation Studies on Soil, 1982 

Canada PMRA, DACO No. 8.2.3.3.1 

Considering Draft (2004-02) OECD Guideline for the Testing of Chemicals: 

Photo-transformation of Chemicals on Soil Surfaces 

GLP: Yes 

Deviations: None 

Validity: Study considered partly valid, only (refer to comments) 

Material and methods:

Test substances: • [Azaspirodecenyl-3-14C]-spirotetramat:

sample ID: BECH 1518; specific activity 3.71 MBq mg-1 (100.2 μCi mg-1); 

radiochemical purity: > 99 % (acc. Radio-HPLC and –TLC); identity and 

purity of the stock solutions was checked 

• [Azaspiro-decenyl-5-14C]-spirotetramat:

sample ID: BECH 1519; specific activity 4.03 MBq mg-1 (108.8 μCi mg-1); 

radiochemical purity: > 98 % (acc. Radio-HPLC and –TLC); identity and 

purity of the stock solutions was checked 

Reference substances: Spirotetramat (unlabelled), spirotetramat-enol, spirotetramat-ketohydroxy, 

dimethyl-benzoic acid. 

Test system and 

experimental design: 

Spirotetramat was applied using both labels at a rate of 1.9 mg ai kg-1 soil, 

(equivalent to 288 g ai ha-1 assuming 1 cm soil depth and 1.5 g cm-3 soil density) 

as drops across the soil surface. Duplicate samples were maintained at 

20 ± 1 °C and irradiated for 7 days. 

Glass flasks filled with 3 g DM of viable soil (3 mm thickness), closed by a quartz 

glass cover and attached with a trap attachment. Moisture adjustment after 

application to 75 % of 1/3 bar moisture was carried out and adjusted in both 

irradiated and dark samples at each sampling interval. 

Control samples were incubated in the dark. 

A supplemental (non-kinetic) experiment (DAT-0 and DAT-7 sampling only)

was conducted with dried soil ‘Molino’ and a second moist soil (‘Laacherhof AIII’) 

to identify soil specific and/or moisture effects. 

For metabolite identification two test systems were treated at 10-times of the 

application rate. 

Irradiation: Continuously artificial irradiation using light from a xenon arc lamp (xenon lamp 

with < 290 nm cut-off filter, approx. 1115 W m-

2 for [3-14C] and 1132 W m-2 for [5-

14C] label). The experimental light intensity of 7 days continuous irradiation is 

equivalent to 37 solar days in June under extreme sunlight conditions at Phoenix, 

AZ (USA, 33 °N) or to 59 days in June under extreme European conditions in 
– 43 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Greece (Athens, EU, 38 °N). 

Sampling intervals: 0, 0.2, 1, 2, 3, 4, and 7 days 

Supplemental experiment: soil ‘Laacherhof AIII’ samplings were conducted at 

DAT-0 and DAT-7, only 

Soil handling: Air-dried, sieved to 2 mm, stored at 4 °C 

Analysis: Soil samples were extracted with 5 mL of acetonitrile/water (1/1, v/v, 0.5 % 

formic acid), two times with 5 mL of acetonitrile/1 M aqueous hydrochloric acid 

(1/1, v/v), and once with 5 mL of acetonitrile. Radioactivity in supernatants were 

analysed by LSC and analyzed separately in the combined organic and 

combined acidic extracts by RP-HPLC with radioactivity detection. Solid samples 

(i.e. soil and paper filters) were combusted and 14C levels were measured using 

LSC. 

Volatile traps: Organic volatiles: polyurethane foam, CO2: soda lime. 

Analysis techniques: LSC,HPLC; HPLC-MS, HPLC-MS/MS, TLC, MS (ESI), NMR 

Detection limits: HPLC: LOQ = 0.96 % of AR, TLC: LOQ = 1.3 % of AR. 

Kinetic evaluation: Simple first order (SFO) kinetics; ModelManager, vers. 1.1.; arithmetic means 

were used for the mentioned replicates 

Table B.8.1.1.3-1: Main soil properties. 

Properties ‘Molino’ ‘Laacherhof AIII’ 

(supplemental test) 

Texture (USDA) Tifton fine sandy loam Loam 

Soil taxonomic classification (USDA) 

Fine-loamy, kaolinitic, 

thermic, plinthic, 

kandiudults 

Loamy, mixed, mesic typic 

Argudalfs 

SCS soil series Ultisol Alfisols 

Sand (USDA) [%] 77.3 49.0 

Silt (USDA) [%] 12.7 31.0 

Clay (USDA) [%] 10.0 20.0 

pH (H2O) 6.1 7.1 

pH (CaCl2) 5.4 6.5 

Organic matter [%] 1.6 2.1 

Organic carbona [%] 0.93 1.2 

CEC [meq/ 100 g DM] 6 10.2 

Field moisture capacity at 0.33 bar [g water/100 g DM] 8.8 17.1 

Microbial Biomass initial [mg microbial C/kg DM] 96 na 

a

 Organic C = organic matter / 1.724 

na not applicable 
– 44 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Findings:

The average material balances for the irradiated test systems ranged from 95.2 % to 101.7 % of AR ([3-

14C] label) and from 95.9 % to 104.7 % of ([5-14C] label). The extractable residues decreased from an 

average of 99.5 % and 103.0 % of AR at DAT-0 to 81.7 % and 76.5 % of AR at DAT-7 for [3-14C] and [5-14C] 

label. The rates of non-extractable residues increased from 0.1 % of AR (both labels) at day 0 to 9.6 % of AR 

([3-14C] label) and 12.1 % of AR ([5-14C] label) at the end of the study. The 14CO2 formation was considerably 

higher in the irradiated system as in the dark controls and reached its maximum at DAT-7 with rates of about 

3.8 % ([3-14C] label) and 7.3 % ([5-14C] label) AR. Organic volatile formation was negligible throughout the 

study (< 1 %). 

For the dark controls, the average material balances ranged from 99.6 % to 103.4 % and from 101.6 % to 

104.5 % of AR, respectively ([3-14C] and [5-14C] label). The extractable radioactivity decreased from an 

average of 99.5 % / 103.0 % of AR at day 0 to 67.4 % / 73.7 % by day 7, respectively. The NER formation 

was significant higher than built during irradiation with rates up to 30.9 % ([3-14C] label) and 27.5 % ([5-14C] 

label) AR at the end of the test. Organic volatile formation was negligible throughout the study (< 1 %). 

In the irradiated test systems ([3-14C] label) the parent compound decreased from an average of 98.3 % of 

AR by DAT-0 to 36.5 % of AR at study termination (7 days). The major metabolite spirotetramatketohydroxy was detected at a maximum of 12.3 % of AR by DAT-7. The minor degradates dimethylbenzoic acid, spirotetramat-glyoxylic amide and spirotetramat-enol were formed at a maximum of 4.8 %, 1.1 

% and 5.3 % of AR at study termination (DAT-7), respectively. Spirotetramat-enol-dimer was not detected in 

comparison to the dark control ([3-14C] label). 

In the irradiated test systems ([5-14C] label) the parent compound decreased from an average of 101.4 % 

of AR by DAT-0 to 30.8 % of AR at the end of the study (7 days). In addition the spirotetramat-ketohydroxy

(max. 20.9 % of AR, mean of replicates, DAT-2) two further major metabolites were detected. 

Spirotetramat-enol reached a maximum of 10.1 % of AR at day 1 (mean of replicates). Metabolite 4-

methoxy-cyclohexanone (only detected in the [5-14C] label samples) reached a maximum of 10.0 % of AR

(mean of replicates) by DAT-2 and then decreased to 6.0 % of AR (mean of replicates) at study termination. 

The minor metabolites identified were spirotetramat-enol-dimer and spirotetramat-glyoxylic amide, which 

were formed at a maximum of 1.9 % of AR (DAT-2, mean of replicates) and 4.1 % of AR (DAT-2, mean of 

replicates), respectively. Dimethyl-benzoic acid was not formed in the [5-14C] label test system. 

In the dark test systems ([3-14C] label), spirotetramat decreased from 98.3 % (DAT-0, mean of replicates) 

to 9.4 % of AR at the end of the study. The two major metabolites identified were spirotetramat-enol and 

spirotetramat-ketohydroxy with maximal amounts of 19.8 % of AR (DAT-2, mean of replicates) and 33.0 % 

of AR (DAT-7, mean of replicates), respectively. Minor transformation products, spirotetramat-enol-dimer and 

spirotetramat-glyoxylic amide, reached a maximum of 5.4 % of AR (DAT-4, mean of replicates) and 2.1 % of 

AR (DAT-2/3, mean of replicates), respectively. 

In dark [5-14C] label test systems the picture was very similar. The two major transformation products, 

spirotetramat-enol and spirotetramat-ketohydroxy, were formed at a maximum of 16.6 % of AR (DAT-4, 

mean of replicates) and 33.9 % of AR (DAT-7, mean of replicates), respectively. The minor degradates 

identified were spirotetramat-enol-dimer 1 and spirotetramat-glyoxylic amide with max. amounts of 8.6 % of 

AR (DAT-3, mean of replicates) and 3.1 % of AR (DAT-1, mean of replicates), respectively. No dimethylbenzoic acid was detected (neither in [3-14C] nor in [5-14C] label test system). 

The experimental DT50 values of spirotetramat in irradiated samples ([3-14C] and [5-14C] label) were 5.0 days 

and 2.4 days, respectively. In the dark controls the experimental DT50 of spirotetramat was 1.2 days ([3-14C] 

label) and 0.6 days ([5-14C] label). It can be concluded that the degradation of spirotetramat was approx. 4 
– 45 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

times faster in the dark systems than in the irradiated systems. It was not possible to calculate the phototransformation rate constants, obtained by subtraction (kirradiated – kdark), because it resulted in negative 

values. 

Supplementary experiment:

On dry irradiated ‘Molino’ soil samples, degradation of spirotetramat was significantly slower than on moist 

irradiated samples (based on 7 DAT findings). However, the pattern of degradates was similar to the moist 

soil samples. Almost no degradation of spirotetramat occurred in the dried soil samples kept under dark 

conditions. 

On moist ‘Laacherhof AIII’ soil the parent compound showed a significant faster degradation than on moist 

‘Molino’ soil based on 7-DAT findings. Formation of degradates under irradiated and dark conditions was 

similar to the moist ‘Molino’ soil. However, the photolytic metabolites dimethyl-benzylic acid and 

spirotetramat-glyoxylic amide were found at distinct higher levels with 21.8 % of AR and 7.7 % of AR by 

7 DAT, respectively. 

Table B.8.1.1.3-2: Distribution and recovery of radioactivity [% of AR] after application of 

spirotetramat ([3-14C] label, 288 g ai ha-1) on moist/dry ‘Molino’ soil surface (mean of duplicate 

samples). 

Conditions DAT Total 

extracteda

14CO2 Org. volatiles NER Recovery 

0 99.5 na na 0.1 99.6 

0.2 97.7 < 0.1 < 0.1 3.0 100.7 

1 96.2 0.1 < 0.1 5.3 101.7 

2 93.3 0.3 < 0.1 6.9 100.6 

3 88.8 1.0 < 0.1 8.0 97.8 

4 87.4 2.1 < 0.1 8.4 97.9 

Irradiated 

(Moist soil)

7 81.7 3.8 < 0.1 9.6 95.2 

Dry soilb

7 95.3 3.3 0.0 3.0 101.6 

0 99.5 na na 0.1 99.6 

0.2 96.7 < 0.1 < 0.1 6.7 103.4 

1 80.7 0.3 < 0.1 21.8 102.8 

2 73.9 0.5 < 0.1 27.8 102.1 

3 68.0 1.0 <0.1 32.8 101.8 

4 70.2 1.0 < 0.1 30.9 102.1 

Dark 

(Moist soil)

7 67.4 1.6 < 0.1 30.9 99.9 

Dry soilb

7 103.5 0.0 0.0 1.3 104.8 

na denotes not applicable 

a

 Including the final acetonitrile extract that was not further considered for analyses due to its low RA content 

b

 Supplemental experiment (only 0 and 7 DAT sampling) 
– 46 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.1.3-3: Distribution and recovery of radioactivity [% of AR] after application of 

spirotetramat ([5-14C] label, 288 g ai ha-1) on moist/dry ‘Molino’ soil surface (mean of duplicate 

samples). 

Conditions DAT Total 

extracteda

14CO2 Org. volatiles NER Recovery 

0 103.0 na na 0.1 103.1 

0.2 99.5 < 0.1 < 0.1 5.2 104.7 

1 95.2 0.6 < 0.1 7.4 103.2 

2 87.6 2.3 < 0.1 9.3 99.2 

3 86.5 3.2 < 0.1 9.8 99.5 

4 81.4 5.3 < 0.1 10.9 97.6 

Irradiated 

(Moist soil)

7 76.5 7.3 < 0.1 12.1 95.9 

Dry soilb

7 94.4 1.8 0.0 2.4 98.6 

0 103.0 na na 0.1 103.1 

0.2 95.1 < 0.1 < 0.1 9.1 104.2 

1 76.6 0.3 < 0.1 25.8 102.6 

2 73.7 0.7 < 0.1 27.3 101.6 

3 74.1 0.9 < 0.1 27.9 103.0 

4 75.5 1.0 < 0.1 28.0 104.5 

Dark 

(Moist soil)

7 73.7 1.4 < 0.1 27.5 102.7 

Dry soilb

7 102.8 0.0 0.0 1.4 104.2 

na denotes not applicable 

a

 Including the final acetonitrile extract that was not further considered for analyses due to its low RA content 

b

 Supplemental experiment (only 0 and 7 DAT sampling) 

Table B.8.1.1.3-4: Distribution and recovery of radioactivity [% of AR] after application of 

spirotetramat, both labels, 288 g ai ha-1) on moist ‘Laacher Hof AIII’ soil surface (mean of duplicate 

samples, supplemental experiment, only 0 and 7 DAT samplings). 

Conditions Label DAT Total 

extracted 

14CO2 Org. volatiles NER Recovery 

[3-14C] 7 80.7 3.5 0.0 13.2 97.4 Irradiated 

[5-14C] 7 67.4 9.6 0.0 14.8 91.8 

[3-14C] 7 68.4 3.5 0.0 26.9 98.9 Dark 

[5-14C] 7 70.9 2.0 0.0 25.7 98.6 
– 47 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.1.3-5: Characterization of extractable radioactivity [% of AR] after application of [3-14C] labelled spirotetramat (288 g ai ha-1) on moist/dry 

‘Molino’ soil surface (individual replicates). 

Spirotetramat Spiro- tetramat- enol Spiro- tetramat- enol- dimer Dimethyl- benzoic acid Spiro- tetramat- glyoxylic- amide Spiro- tetramat- keto- hydroxy ROI 3 ROI 8 ROI 9 ROI 10 ROI 11 Unidenti- fied diffuse RA Conditions DAT 

A B A B A B A B A B A B A B A B A B A B A B A B 

0 98.1 98.4 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 

0.2 94.2 95.1 1.4 1.5 0.0 0.0 0.0 0.0 0.0 0.0 1.3 1.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 

1 87.0 81.4 2.0 5.6 0.0 0.0 0.0 2.7 0.0 0.0 6.4 5.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.3 0.0 0.0 0.0 0.0 2 73.3 76.4 3.4 1.9 0.0 0.0 3.5 1.9 0.0 0.0 8.3 9.3 0.0 0.0 0.0 2.5 0.0 0.0 2.9 2.3 0.0 0.0 0.0 0.0 3 69.7 67.8 0.0 3.1 0.0 0.0 3.8 3.1 0.0 1.9 8.3 8.5 0.0 0.0 0.0 0.0 0.0 0.0 2.5 2.3 0.0 0.0 3.5 2.3 4 53.7 53.8 1.7 2.2 0.0 0.0 3.8 4.2 1.4 0.0 12.9 10.0 0.0 0.0 4.6 2.7 0.0 0.0 2.8 3.7 3.0 4.9 3.6 4.5 

Irradiated 

(Moist soil)

7 33.0 39.9 5.6 5.0 0.0 0.0 3.6 5.9 2.2 0.0 10.9 13.8 0.0 0.0 0.0 0.0 2.6 5.3 4.0 4.0 5.0 3.5 11.6 5.6 

Dry soilb 7 77.0 ± 2.3 0.0 ± 0.0 nd 1.8 ± 0.2 1.6 ± 0.1 7.3 ± 0.1 nd nd nd 0.7 ± 0.7 1.7 ± 0.1 0.8 ± 0.8 

0 98.1 98.4 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 

0.2 92.8 92.0 1.4 2.4 0.0 0.0 0.0 0.0 0.0 0.0 2.0 2.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 

1 48.6 57.8 15.4 9.2 2.6 1.8 0.0 0.0 1.5 0.0 11.8 10.8 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2 26.2 27.3 19.8 19.9 3.7 3.0 0.0 0.0 1.9 2.3 19.0 18.9 0.0 0.0 1.0 0.0 0.0 0.0 1.1 1.4 0.0 0.0 0.0 0.0 3 19.0 17.1 17.6 19.0 4.1 4.1 0.0 0.0 1.4 2.8 23.1 22.0 0.7 0.0 0.0 0.0 0.0 0.0 1.5 2.2 0.0 0.0 0.0 0.0 4 13.5 14.5 15.8 15.8 5.1 5.8 0.0 0.0 1.5 0.0 28.7 30.4 1.7 0.0 0.0 0.0 0.0 0.0 2.8 2.2 0.0 0.0 0.0 0.0 

Dark 

(Moist soil)

7 10.1 8.8 13.5 14.9 5.0 4.2 0.0 0.0 0.0 0.0 32.1 33.8 2.4 1.4 0.0 0.0 0.0 0.0 3.0 2.9 0.0 0.0 0.0 0.0 

Dry soilb 7 98.0 ± 1.7 0.4 ± 0.4 nd 0.0 ± 0.0 0.6 ± 0.6 4.4 ± 0.4 nd nd nd 0.0 ± 0.0 0.0 ± 0.0 0.0 ± 0.0 

b Supplemental experiment (mean ± STD) Table B.8.1.1.3-6: Characterization of extractable radioactivity [% of AR] after application of [3-14C] labelled spirotetramat (288 g ai ha-1) on moist 

‘Laacherhof AIII’ soil surface (mean ± STD, supplemental experiment). 

Conditions DAT Spiro- tetramat Spiro- tetramat- enol Spiro- tetramat- enol- dimer Dimethyl- benzoic acid Spiro- tetramat- glyoxylic- amide Spiro- tetramat- keto- hydroxy ROI 1 ROI 3 ROI 9 ROI 10 ROI 11 ROI 13 Unidenti- fied diffuse RA 

Irradiated 7 11.3 ± 2.5 1.2 ± 1.2 4.2 ± 0.5 21.8 ± 2.0 7.7 ± 1.7 24.7 ± 4.3 0.0 ± 0.0 0.6 ± 0.6 1.6 ± 1.6 1.7 ± 1.7 3.2 ± 0.6 0.0 ± 0.0 1.7 ± 0.3 

Dark 7 4.0 ± 0.3 9.1 ± 0.6 14.4 ± 0.0 0.0 ± 0.0 0.0 ± 0.0 26.9 ± 1.6 5.2 ± 0.0 1.3 ± 1.3 0.0 ± 0.0 0.0 ± 0.0 0.0 ± 0.0 3.5 ± 0.1 2.2 ± 0.6 
– 48 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.1.3-7: Characterization of extractable radioactivity [% of AR] after application of [5-14C] labelled spirotetramat (288 g ai ha-1) on moist/dry 

‘Molino’ soil surface (individual replicates). 

Spirotetramat 

Spirotetramatenol Spiro- tetramat- enol- dimer Spiro- tetramat- glyoxylic amide Spiro- tetramat- keto- hydroxy 4- Methoxy- cyclo- hexa- none ROI 1 ROI 11 ROI 13 ROI 15 ROI 16 ROI 17 ROI 18 Unidenti- fied diffuse RA Condi tions D A T 

A B A B A B A B A B A B A B A B A B A B A B A B A B A B 

0 100.7 102.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 

0.2 82.4 81.8 9.4 10.6 0.0 0.0 0.0 1.4 5.9 6.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 

1 51.8 62.7 9.5 10.7 1.7 1.5 3.4 2.5 19.0 14.1 7.8 4.4 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2 38.5 35.8 7.0 9.5 1.4 2.3 4.4 3.9 19.3 22.5 10.7 9.3 0.0 0.0 1.5 0.0 0.0 0.0 0.0 1.5 2.2 2.8 0.0 0.0 0.0 0.0 0.0 0.0 3 38.9 32.9 8.9 6.8 0.0 0.0 3.6 3.4 16.8 22.3 6.2 11.4 0.0 0.0 2.6 0.0 0.0 0.0 2.2 2.4 2.3 3.3 0.0 0.0 3.3 3.9 0.0 0.04 31.3 35.1 4.2 2.6 0.0 0.0 1.9 2.5 19.4 18.9 8.7 7.5 0.0 0.0 0.0 0.0 0.0 0.0 2.8 4.2 4.3 6.9 0.0 0.0 5.0 4.4 1.1 0.0 

Irradiated 

(Moist 

soil)

7 29.7 31.8 3.1 4.9 0.0 1.6 3.0 3.8 18.2 15.1 6.4 5.7 0.0 0.0 0.0 0.0 0.0 0.0 4.4 2.1 3.8 2.0 1.9 0.0 3.7 4.2 2.1 3.4 

Dryb 7 76.9 ± 3.6 1.2 ± 0.4 nd 1.6 ± 0.2 5.6 ± 0.5 5.0 ± 0.1 nd nd nd nd nd nd nd 2.4 ± 1.2 

0 100.7 102.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 

0.2 77.2 75.9 10.7 11.8 0.8 1.3 0.0 0.0 5.0 5.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 

1 22.8 25.9 14.5 13.9 6.9 6.0 3.2 3.0 26.1 23.6 0.0 0.0 2.1 2.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2 16.7 13.0 13.7 15.6 7.4 8.2 3.3 2.2 29.8 28.7 0.0 0.0 1.9 3.9 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 3 10.8 9.7 15.3 15.8 8.6 8.6 2.0 2.4 28.7 31.5 0.0 0.0 2.4 2.7 0.0 0.0 1.5 2.5 0.0 0.0 0.0 0.0 0.0 0.0 3.3 0.0 0.0 0.0 4 8.6 8.5 16.1 17.0 6.3 6.7 2.1 2.4 32.4 32.8 0.0 0.0 2.6 2.6 0.0 0.0 1.8 2.3 0.0 0.0 0.0 0.0 0.0 0.0 2.9 2.8 0.0 0.0 

Dark

(Moist 

soil)

7 8.6 5.8 12.3 12.7 8.7 7.2 0.0 2.0 34.0 33.8 0.0 0.0 2.8 2.4 0.0 0.0 2.8 4.7 0.0 0.0 0.0 0.0 0.0 0.0 3.4 3.2 0.0 0.0 

Dryb 7 96.4 ± 0.0 1.1 ± 0.3 nd 1.3 ± 0.0 3.5 ± 0.2 0.0 ± 0.0 nd nd nd nd nd nd nd 0.3 ± 0.3 

b Supplemental experiment (mean ± STD) Table B.8.1.1.3-8: Characterization of extractable radioactivity [% of AR] after application of [5-14C] labelled spirotetramat (288 g ai ha-1) on moist 

‘Laacherhof AIII’ soil surface (mean ± STD, supplemental experiment). 

Condi

tions 

D 

A 

T 

Spirotetramat Spiro- tetramat -enol Spiro- tetramat- enol-dimer Spiro- tetramat- glyoxylic amide Spiro- tetramat- keto- hydroxy 4- Methoxy cyclo- hexa- none ROI 1 ROI 3 ROI 13 ROI 15 ROI 16 ROI 18 ROI 20 Unidenti- fied diffuse RA 

Irrad. 7 5.0 ± 1.8 2.6 ± 0.2 3.2 ± 0.4 5.2 ± 3.9 22.8 ± 4.6 3.5 ± 1.5 0.7 ± 0.7 1.2 ± 1.2 1.5 ± 1.5 2.7 ± 0.1 2.0 ± 0.5 4.9 ± 0.3 1.9 ± 0.0 9.1 ± 0.9 

Dark 7 4.1 ± 0.4 9.5 ± 0.7 10.4 ± 2.3 0.0 ± 0.0 20.1 ± 0.2 0.0 ± 0.0 3.5 ± 0.7 1.9 ± 0.2 4.5 ± 0.3 2.5 ± 0.5 0.0 ± 0.0 2.9 ± 0.9 1.5 ± 0.0 8.1 ± 1.1 
– 49 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.1.3-9: Calculated DT50 and DT90 of spirotetramat on ‘Molino’ soil surface under irradiated 

and dark conditions using SFO kinetics ([3-14C] and [5-14C] label). 

Soil Label Test system DT50 [days] DT90 [days] R2

chi2

 error [%]a

Kinetics 

Irradiated 5.0 16.6 0.991 2.2 SFO 

[3-14C] 

Dark 1.2 3.9 0.986 7.4 SFO 

Irradiated 2.4 8.1 0.830 15.6 SFO 

‘Molino’ 

[5-14C] 

Dark 0.6 1.9 0.973 13.4 SFO 

a

 calculated by the reviewer 

Conclusion:

It was not possible to assess the rate of photodegradation of spirotetramat on moist soil because most

degradation was due to microbial activity (which was more active under dark conditions). Under dry 

conditions microbial activity was reduced and spirotetramat photodegraded, but this (supplemental) study 

had too few data points to calculate a half-life. Four major (> 10 % of AR) transformation products were 

found in the irradiated soil samples on moist soils, i.e. spirotetramat-enol, spirotetramat-ketohydroxy, 4-

methoxy-cyclohexanone (only [5-14C] label) and dimethyl-benzoic acid (only [3-14C] label). Minor 

transformation products determined were spirotetramat-glyoxylic amide and spirotetramat-enol dimer. 

Reviewer comments:

• For the photolytic metabolite 4-methoxy-cyclohexanone a separate aerobic degradation rate study 

was conducted (refer to B.8.1.2.3, aerobic degradation rate of relevant metabolites). 

• Owing to the fact, that the irradiated test system was likely to be strongly affected by decreased 

biological activity, calculation of DT50 values under environmental conditions is not considered to 

result in reliable values. 

• Metabolite dimethyl-benzoic acid was found > 10 % of AR in the supplemental experiment (only 

7 DAT sampling available) with ‘Laacherhof AIII’ soil with 21.8 % of AR. Maximum observed levels of 

dimethyl-benzoic acid in the main study (kinetic) part (‘Molino’ soil) were 4.8 % of AR (mean). Both 

test systems suffered from low microbial activity owing to the experimental conditions. In the outdoor

metabolism study (B.8.1.1.1; Babszinski, 2006a), conducted on the same two soils to simulate real 

environmental conditions including formulated application and natural sunlight, maximum levels of 

dimethy-benzoic acid found were 3.3 % of AR (decreasing thereafter) indicating that this metabolite is

unlikely to occur at relevant amounts in viable soils. Therefore, dimethyl-benzoic acid is not 

considered a relevant soil photolysis metabolite by the reviewers. 

• Reviewers from the US-EPA and from the PMRA required further studies using sterile soils to 

minimize microbial degradation. On request the notifier (BCS) provided further information:

BCS: ‘The study was conducted according to established guidelines as required with viable soil 

(EPA § 161-3 and OECD Draft TG dated Feb 2002). As acknowledged by the reviewers, 

considering all the results on the behaviour of spirotetramat in soils, BCS regards the phototransformation of spirotetramat of no greater importance compared to the dark biodegradation. 

Thus, by using a sterile soil, not much information to real-world exposure would be added. The 

real world situation is better described by the results of an outdoor soil metabolism study, 

regarded as an adequate supportive study, better than a highly artificial study with sterile soil. In 

general the main objective of the photo-transformation study on soil surface is not to provide 

experimental DT50 and DT90 (it is not regarded as a rate of degradation study), but to elaborate 

what further metabolites should be considered for TFD studies and for exposure risk 

assessments in soil. It is clearly regarded as a route of degradation study.’

However, to overcome several uncertainties related to the photodegradation rate of spirotetramat and 

formation of photolysis metabolites (see comments above), the notifier (BCS) is currently conducting 

an additional soil photolysis study on sterile soil. This study is expected for submission by end of 

2008. 
– 50 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

B.8.1.1.4 Summary on route of degradation in soil (laboratory) 

The route of degradation of spirotetramat was established on 3 EU soils and one US soil in two studies using 

either spirotetramat or spirotetramat-enol (which is rapidly released from spirotetramat) as parent. The latter 

study (using alkaline extraction) was conducted to overcome metabolite instability observed in the 

spirotetramat study during the acidic extraction procedure. In this respect, only the degradation study using 

spirotetramat-enol as parent is considered relevant for evaluation of maximum occurrence (and degradation 

rates) of metabolites. However, despite the analytical problems, both studies are consistent in their overall 

degradation pathway of spirotetramat in aerobic soil. 

Aerobic laboratory soil degradation studies were conducted under static conditions (no flow through 

systems). Both test systems (static and flow through) are options outlined in the test guidelines. From the 

notifier’s long-term experience with the static systems the validity of that test system is fully proven indicated 

by evolution of carbon dioxide formed till the end of the aerobic studies. Furthermore, the terminal biomass 

determinations indicate a viable test system through the entire test duration. 

Under standard aerobic conditions (20 °C), the metabolism of spirotetramat ([3-14C] label) was shown to 

proceed via three pathways which all start with the hydrolytic cleavage of the spirotetramat ester into the 

spirotetramat-enol (Figure 2.5.2-1). Following the major degradation pathway, spirotetramat-enol is rapidly 

oxidized at the benzylic carbon position into spirotetramat-ketohydroxy which is hydrolytically opened into 

spirotetramat-MA-amide and finally mineralized into CO2. In the second (minor) pathway demethylation of 

spirotetramat-enol into spirotetramat-desmethyl-enol and oxidation of this degradate into spirotetramat-oxoenol occurred. In a third degradation pathway spirotetramat-enol-dimer 1 and spirotetramat-enol-dimer 2 

were pretended to be built through oxidative enol dimerization. However, this pathway is regarded as non 

relevant under environmental conditions, because the formation of dimers is considered an artificial process 

mainly caused by the hot-spot application in this laboratory tests. 

As mentioned above, no final conclusion onto the maximum occurrence (and degradation rates) of 

metabolites of spirotetramat could be drawn from the parent degradation study. In the second degradation 

study, using spirotetramat-enol as parent ([3-14C] and [5-14C] label) and the same test soils as used in the 

parent degradation study, spirotetramat-ketohydroxy was observed at maximum amounts of 24.0 % of AR 

(by 1 DAT), spirotetramat-MA-amide was observed at maximum amounts of 5.2 % of AR by 7 DAT (only one 

sample > 5 % of AR). No other metabolite was observed > 5 % of AR in this study. Spirotetramat-oxoketohydroxy, a metabolite previously not found, was a very minor compound and was not quantifiable. 

Spirotetramat-desmethyl-enol was observed at maximum amounts of 1.8 % of AR by 4 DAT. Since the 

maximum occurrence of spirotetramat-enol can not be adequately derived from the parent study, maximum 

occurrence of spirotetramat-enol was set to 100.0 % of AR in all risk assessments for conservative reasons. 

Formation of CO2 in the spirotetramat degradation study was in a range of 9.7 – 19.4 % of AR by 50 DAT 

(i.e. the study termination in case of the EU soils), in the US soil, CO2 further increased from 9.7 % of AR by 

50 DAT to 15.3 % of AR by study termination (360 DAT). No volatile organics could be detected. The soil 

with the highest content of microbial biomass showed the highest mineralization rate. Formation of CO2 in 

the spirotetramat-enol degradation study was in a range of 16.7 – 43.0 % of AR by study termination (119 

DAT). Significant higher 14CO2 amounts were released from spirotetramat-enol labelled in the [3-14C] 

position. No volatile organics could be detected. 

In the spirotetramat study, the portion of non-extractable radioactivity (NER) rapidly increased (by 1 – 3 

DAT), reaching more or less a plateau concentration in the range of approx. 22 – 35 % of AR, hardly 

decreasing thereafter. A similar but even more pronounced formation of NER was determined in the 

spirotetramat-enol study using a slightly alkaline extraction procedure. Directly after application (0-DAT 
– 51 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

sampling) already 4.2 – 28.4 % of AR was bound to the soil matrix. Amounts of NER rapidly increased 

further to reach a plateau concentration by 1 DAT and thereafter. Plateauing concentration was in a range of 

40 – 60 % of AR. No significant decrease of NER was found with time. 

Further attempts were undertaken by the notifier to identify/characterize the pronounced NER fraction in both 

experiments by means of humic acid fractionation. A partitioning of the heterogeneous NER into humic acid, 

fulvic acid and humin like fractions was observed, with the major portion belonging to the fulvic acid fraction 

and a significant portion bound to soil in the insoluble humin fraction. 

During the evaluation, there was some discussion about the relevance of this extensive formation of NER (or 

bound residues, BR) found in the aerobic lab degradation studies (especially, when spirotetramat-enol was 

used as parent). The general point is that the notifier’s statement, that ‘NER is immobile and not (readily) 

bioavailable or bioaccessable’, is not supported (by data). Reviewers from the PMRA believe that studies 

conducted on sterile and non-sterile soil may help to clarify this point. The EU project ‘FOOTPRINT’1 points 

out that ‘there is no agreement amongst EU Member States on how NER should be treated. The possible 

key to this question could be NER ‘bioavailability’ (Craven, 2000)2. The current approach which is most often 

adopted is to treat soil NER in the same way as persistent compounds (Craven & Hoy, 2005)3. Thus, for 

these authors, the full range of environmental fate, long term effects and crop residue tests required to 

identify any risks posed by NER are brought into play. This position is however not consensual. The 

Scientific Committee on Plants (SCP) provided a view on the issue in 1999 after analysis of the available 

literature4

. The SCP noted that small fractions of NER may be released by a variety of processes and 

become potentially bioavailable. The opinion of the SCP (1999) is that the fractions of NER which are 

released are low and any concern over their ecotoxicology or effect on succeeding crops should have been 

addressed during studies required under Annex II and III for the active substance and relevant metabolites. 

Thus, for the SCP, the fractions released from NER have little significance from a regulatory viewpoint.’ 

In an additional outdoor study, the degradation of [3-14C] labelled spirotetramat (spirotetramat formulated as 

an OD 100) was investigated under more realistic environmental conditions including natural sunlight. In 

comparison to the laboratory degradation study, beside the already mentioned metabolites three new 

metabolites were identified within this study: spirotetramat-glyoxylic amide (maximum 2.3 % of AR by 7

DAT), dimethyl-benzoic acid (3.3 % of AR by 7 DAT) and spirotetramat-ketohydroxy-carboxy (1.3 % of AR). 

Further, it has to be concluded that the formation of the spirotetramat-enol dimers within the outdoor study 

with another application technique (broadcast application) was about ≤ 1.5 % of AR. Maximum formation of 

NER was distinct lower than observed in the laboratory studies with 16.8 % of AR by 63 DAT decreasing 

thereafter indicated an enhanced overall degradation of the parent and its metabolites in soil under real 

outdoor conditions in comparison to the laboratory degradation studies. 

 

1

 FOOTPRINT: Creating tools for pesticide risk assessment and management in Europe. A project funded by the 

European Commission under the 6th Framework Programme (http://www.eu-footprint.org) 

2

 Craven A. (2000) Bound residues of organic compounds in the soil: the significance of pesticide persistence in soil and 

water: a European regulatory view. Environmental Pollution, 108: 15-18. 

3

 Craven A. & Hoy S. (2005) Pesticide persistence and bound residues in soil – regulatory significance. Environmental 

Pollution, 133: 5-9. 

4

 SCP Opinion on Draft GD on persistence in soil (DG iY-9188/IV/97-Rev. 5, 1998), dated 1999 
– 52 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

NH

O

O

O O

CH3

CH3

H3C

NH

O

O

CH3

CH3

OH

CO2

N

H

O

CH3

CH3

OH

COOH

NH

HO

O

CH3

CH3

OCH3

NH

HO

O

CH3

CH3

OH

NH

HO

O

CH3

CH3

O

NH

O

CH3

CH3

NH

O

O

CH3

CH3

OH

OH

NH

O

O

CH3

CH3

OH

O

N

H

O

CH3

CH3

CH O COOH 3

CH3

O

COOH

OCH3

NH

O

O

CH3

CH3

O

OCH3

OCH3

OCH3

NH

HO

O

CH3

CH3

OCH3

OCH3

OCH3

OCH3

NH

O

O

R

R1

OH

OCH3

NH

HO

O

CH3

CH3

OH

OCH3

BYI08330

Enol

Ketohydroxy

Bound residues

(- 2 H)

Enol-dimer 1

2

MA-amide

Desmethyl-enol

Oxo-enol

Hydrolysis

Oxidation

x 2

Hydrolysis

Desmethylation

Oxidation

Enol-dimer 2

Desmethylation

ketohydroxy

DesmethylOxo-ketohydroxy

Oxidation

*

Benzoic 

acid**

Methoxy 

Molecule cyclohexanone

cleavage

Glyoxylic amide**

Oxidation

***

x 2

(- 2 H)

Oxidation

Oxidation

Ketohydroxycarboxy

Oxidation

R,R1= -CH3, -COOH

Oxidation

Oxidation

cleavage

Molecule

Dihydroxy

Oxidation

Hydratization

 *: postulated intermediate; ** and *** were identified in studies including light (dependent on radiolabel used) 

Figure B.8.1.1.4-1: Proposed metabolic pathway for spirotetramat (BYI08330) in soil. 
– 53 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Under anaerobic conditions the degradation pathway is almost identical to the degradation pathway 

obtained in aerobic soil. It was shown that spirotetramat declines quickly in a subsequently flooded anaerobic 

soil situation. The detected metabolites were almost identical to those formed upon the aerobic 

transformation in the aerobic metabolism study, except of the minor metabolite spirotetramat-di-hydroxy. But 

spirotetramat-di-hydroxy was formed in the aerobic aquatic metabolism study. Therefore it can be excluded 

that this metabolite will be specially formed under anaerobic conditions. 

It was not possible to assess the rate of photodegradation of spirotetramat on moist soil because most 

degradation was due to microbial activity (which was more active under dark conditions). Under dry 

conditions microbial activity was reduced and spirotetramat photodegraded, but the (supplemental) study 

had too few data points to calculate a half-life. In general, phototransformation on moist soil surfaces is not 

considered to significantly contribute to the overall dissipation of spirotetramat from the environment owing to 

the extremely rapid degradation under moist conditions. Four major transformation products (> 10 % of AR) 

were found in the irradiated soil samples, i.e. spirotetramat-enol, spirotetramat-ketohydroxy, 4-methoxycyclohexanone (only observable using [5-14C] labelled parent) and dimethyl-benzoic acid (only observable 

using [3-14C] labelled parent). Minor transformation products determined were spirotetramat-glyoxylic amide 

and spirotetramat-enol dimer. 4-Methoxy-cyclohexanone and dimethyl-benzoic acid were not found in dark

samples indicating that these metabolites are photolysis metabolites, only. Dimethyl-benzoic acid was shown 

not to exceed 3.3 % of AR in the outdoor study including natural sunlight. Therefore, dimethyl-benzoic acid is 

not considered a relevant soil photolysis metabolite. In case of 4-methoxy-cyclohexanone, which could not 

be determined in the outdoor study owing to the label used, a separate degradation study was conducted

(refer to ‘rate of degradation’ section) in order to derive appropriate degradation rates for this photolysis 

metabolite in viable soils. 

To overcome several uncertainties related to the photodegradation rate of spirotetramat and formation of 

photolysis metabolites (see comments above), the notifier (BCS) is currently conducting an additional soil 

photolysis study on sterile soil. This study is expected for submission by end of 2008. 

Table B.8.1.1-10: Summary on maximum occurrence [% of AR] of metabolites of spirotetramat in soil 

degradation studies (numbers in brackets indicate day of maximum occurrence). 

Compound 

Parent 

degradation 

studya

Spirotetramat

-enol 

degradation 

study 

Outdoor 

study 

Anaerobic 

degradation 

study (entire 

system) 

Soil 

photolysis 

study 

Spirotetramat-enol 24.3 (3) -

b

 7.8 (7) 54.6 (180) 10.1 (1) 

Spirotetramat-ketohydroxy 16.3 (1) 24.0 (1) 25.3 (14) 19.3 (1) 24.7 (7) 

Spirotetramat-MA-amide 6.4 (7) 5.2 (4) 6.2 (28) 7.2 (180) nd 

Spirotetramat-desmethyl-enol 3.7 (179) 2.0 (4) nd nd nd 

Spirotetramat-oxo-enol 1.2 (50) nd nd nd nd 

Spirotetramat-glyoxylic amide nd nd 2.3 (7) nd 7.7 (7) 

Spirotetramat-di-hydroxy nd nd nd 3.2 (32, 90) nd 

Dimethyl-benzoic acidc nd nd 3.3 (7) nd 21.8 (7) 

4-Methoxy-cyclohexanone no no no no 10.0 (2) 

Spirotetramat-enol-dimer 1d 12.7 (7) 5.0 (6) 1.5 (28) 7.0 (6) 4.2 (7) 

Spirotetramat-enol-dimer 2d 9.2 (30) 3.6 (14) 0.9 (7) 4.6 (180) nd 

no denotes not detected 

no denotes not observable (owing to the label used)

a

 Not considered relevant for evaluation of maximum occurrence of metabolites owing to analytical reasons 

b

 Set to 100.0 % for risk assessment, worst case assessment 

c

 Not considered relevant for risk assessment owing to the fact, that dimethyl-benzoic acid was shown not to exceed 3.3 % of AR in an 

representative outdoor study (B.8.1.1.1; Babczinski, 2006a) including natural sunlight (study conducted with the same soils used in the 

laboratory soil photolysis study) 

d

 Not considered relevant for risk assessment owing to artifactual formation during hot-spot application (hardly observed under realistic 

outdoor and field conditions, see position paper Hellpointner et al., 2007) 
– 54 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

B.8.1.2 Rate of degradation in soil (OECD Annex IIA, 7.2, IIIA, 9.1) 

B.8.1.2.1 Aerobic degradation rate of the active substance at 20 °C (OECD Annex IIA, 7.2.1, IIIA, 

9.1.1) 

Data on the aerobic degradation rate of spirotetramat at 20 °C are available from one degradation route and 

rate study (Babczinski, 2005). In addition, the kinetic evaluation was described in a separate report, in which 

the methods and results of the respective kinetics calculations were described more in detail. 

• Aerobic degradation in four soils (20 °C, [3-14C] label) 

Full study details are given under B.8.1.1.1. 

Reference: Degradation of BYI08330 in Four Soils Under Aerobic Conditions: Kinetic 

Evaluation 

Author(s), year: Ramanarayanan, T., Roepke, B., 2006 

Study/report number: M-277096-01-2, MEF-05/249 

Guideline(s): FOCUS guidelines (FOCUS, 2000 and FOCUS, 2006) for kinetics modelling were 

considered 

GLP: Calculations – not applicable 

Validity: Study considered acceptable 

Material and methods:

The degradation behaviour of [3-14C] labelled spirotetramat was studied in three European soils and one US 

soil under laboratory aerobic conditions at 20 °C (B.8.1.1.1., Babczinski, 2005). A kinetic modelling analysis 

of residue data of spirotetramat was conducted using MatLab 7.0.4. (MatLab, 2005). The degradation kinetic 

calculations of the major metabolites were based on the spirotetramat-enol degradation study and were 

calculated in a separate study (Röpke, 2006a). 

For moisture normalization the correction factor of each soil was estimated according to the 

recommendations of the FOCUS working group. Therefore, FOCUS default values for each individual soil 

type for both, reference moisture content (Θref) and study moisture content (Θ), were used (see Table 

B.8.1.2.1-1). 

For characterization of the degradation behaviour of spirotetramat single first order (SFO) and bi-phasic 

kinetic (FOMC and DFOP) models were used. C0 was calculated by the model. 

The goodness of fit was assessed by visual inspection and an error criterion based on a chi-square (χ

2

) test. 

A t-test was employed to identify the probability that a parameter is not significantly different from zero. The 

coefficients of determination r2

 were also reported for comparative reasons. The kinetics modelling tool is 

built within MatLab (Vers. 7.0.4). The tool uses internal routines (Levenberg-Marquardt) of MATLAB to 

optimize the model parameters to fit a chosen kinetics model to the metabolism study data. The objective 

function used for the optimization of the parameters was to minimize the sum of squares between the 

calculated and observed time series data. 

Findings:

The results of the SFO calculation showed that spirotetramat degraded very quickly during the first day to 

less than 10 % of AR in all four soils. Afterwards the degradation slowed down. The visual assessment of the 

measured and the observed data showed that the SFO kinetic model explains the degradation of 
– 55 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

spirotetramat very well during the initial periods of the study (less than 1 day) and underestimates the 

concentrations during the later time points for all soils (especially for ‘Molino’ soil). Therefore bi-phasic 

models as FOMC and DFOP were used to improve the visual and statistical assessment of the fits 

(according to trigger evaluation). 

Comparing the visual fits and the goodness of fit parameters between the two chosen bi-phasic models it can 

be concluded that the DFOP model showed a more suitable fit than the FOMC model. The estimated DT50

values were very close to the values derived from the SFO model fit, but the DT90 values were somewhat 

higher.
– 56 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.2.1-1: Normalization factors for soil moisture (fMoist). 

Moisture content 

during study 

[g 100 g-1] 

Moisture content 

at pF2 

[g 100 g-1]c

fMoist

Soil Soil texture (USDA) Study moisture MWHC [g 100 g-1]a Moisture content at pF 2.5b [g 100 g-1] Θ Θref 7.0 Moist f   ΘΘ = ref

‘Laacherhof AXXa’ Sandy loam 50 % of MWHC 27 (15) 13.5 19 0.79 ‘Laacherhof AIII’ Silt loam 50 % of MWHC 32 (21) 16.0 26 0.71 ‘Hoefchen’ Silt 50 % of MWHC 31 (21) 15.5 27 0.67 ‘Molino’ Sandy loam 75 % of MC at pF2.5 (27) 15 11.3 19 0.69 a MWHC for classified soils taken from the FOCUS report (FOCUS, 2000) b Estimates for classified soils taken from the FOCUS report (FOCUS, 2000) c Estimates for classified soils taken from the FOCUS report (FOCUS, 2000)
– 57 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.2.1-2: Degradation rates of spirotetramat in aerobic lab studies (20 °C) based on SFO 

kinetics – corrected by the reviewer.a

Soil 

C0 

[% of 

AR] 

DT50 

[days] 

DT90 

[days]a χ

2

 error [%] R

2 p

of t-test 

DT50 norm 

[days] 

‘Laacherhof AXXa’ 91.5 0.21 0.69 8.52 > 0.99 < 0.001 0.17 

‘Laacherhof AIII’ 91.2 0.23 0.77 8.81 > 0.99 < 0.001 0.16 

‘Hoefchen’ 93.2 0.08 0.28 9.50 > 0.99 < 0.001 0.05 

‘Molino’ 94.5 0.33 1.09 21.79 0.99 < 0.001 0.23 

a Wrong values were transferred from the result sheets to the summarizing study report. 

Table B.8.1.2.1-3: Degradation rates of spirotetramat in aerobic lab studies (20 °C) based on FOMC 

kinetics – corrected by the reviewer.a

Soil 

C0 

[% of 

AR] 

DT50 

[days] 

DT90 

[days] 

DT50recalc

b

[days] 

χ

2

 error 

[%] R

2 p

of t-test 

DT50recalc

norm 

[days] 

‘Laacherhof AXXa’ 91.8 0.25 1.04b 0.31 6.51b > 0.99 - 0.24 

‘Laacherhof AIII’ 91.6 0.23 1.09b 0.33 7.47b > 0.99 - 0.23 

‘Hoefchen’ 93.2 0.01 0.44 0.13 3.61 > 0.99 - 0.09 

‘Molino’ 96.6 0.26 2.61 0.79 16.5 > 0.99 - 0.55 

a Wrong values were transferred from the result sheets to the summarizing study report. 

b

 SFO-DT50 recalculated from the FOMC-DT90 divided by 3.32. 

Table B.8.1.2.1-4: Degradation rates of spirotetramat in aerobic lab studies (20 °C) based on DFOP 

kinetics. 

Soil 

C0 

[% of 

AR] 

DT50 

[days] 

DT90 

[days] 

DT50recalc

a

[days] 

χ

2

 error 

[%] R

2 p

of t-test 

DT50recalc

norm 

[days] 

‘Laacherhof AXXa’ 91.7 0.24 0.89 0.27 1.37 > 0.99 < 0.001 0.21 

‘Laacherhof AIII’ 91.5 0.26 0.97 0.29 0.81 > 0.99 < 0.001 0.21 

‘Hoefchen’ 93.2 0.09 0.34 0.10 4.0 > 0.99 < 0.001 0.07 

‘Molino’ 95.5 0.30 1.26 0.38 6.12 > 0.99 < 0.001 0.26 

a

 SFO-DT50 recalculated from the DFOP-DT90 divided by 3.32. 

Conclusion:

The DFOP kinetic model fitted the experimental data best in terms of visual assessment and the χ

2

 scaled 

errors. However, SFO is the preferred model for deriving parameters to be used in environmental fate 

models. The visual assessment of the SFO plots indicated an acceptable fit of the data to the SFO model for 

three of the four soils (‘Laacherhof AXXa’, ‘Laacherhof AIII’ and ‘Hoefchen’), the χ

2

 scaled errors were below 

10 % indicating good agreement between the modelled and measured data. Despite the fact, that the χ

2

scaled error in case of the ‘Molino’ soil was estimated to be 8 % higher than the indicator value suggested by 

the FOCUS group (i.e. 15 %, FOCUS, 2006), the SFO model was found to adequately represent all four 

studied soils. 

It can be concluded that spirotetramat degrades very quickly with DT50norm values < 1 day. 

Reviewer comments:

• Normalization procedure was based on FOCUS default values for each individual soil type for both, 

reference moisture content (Θref) and study moisture content (Θ). Although the study moisture 

content was measured and is therefore exactly known (except for soil Molino), the approach by the 

notifier is considered acceptable. 

• The notifier stated normalized FOMC- and DFOP-DT50 values in the study report. The reviewer is of 

the opinion that normalization of non-SFO kinetics is not advisable at all since processes which 

result in non-SFO kinetics behaviour (e.g. increasing adsorption with time, decreasing bioavailability, 

etc.) do not necessarily follow common normalization assumptions (moisture, temperature correction 
– 58 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

factors, etc.). Therefore, the reviewers based the normalization procedure on recalculated SFO-DT50

values (i.e. FOMC-DT90 or DFOP-DT90 divided by 3.32), which is generally considered a 

conservative approach. 

B.8.1.2.2 Aerobic degradation of the active substance at 10 °C (OECD Annex IIA, 7.2.2) 

The rate of aerobic degradation of spirotetramat at 10 °C was calculated by the notifier using the Q10-value of 

2.2 (see Tier 2, AII, 7.2.2): Multiplying the DT50 values of 0.08 to 0.33 days (SFO kinetics) by a factor of 2.2 

will result in DT50 values between 0.18 and 0.73 days. 
– 59 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

B.8.1.2.3 Aerobic degradation of relevant metabolites at 20 °C (OECD Annex IIA, 7.2.3) 

Data on the aerobic degradation rate of major spirotetramat metabolites are available from one degradation 

route and rate study with spirotetramat-enol (B.8.1.1.1). The kinetic evaluation was described in a separate 

report, in which the methods and results of the respective kinetics calculations were described more in detail. 

• Spirotetramat-enol, spirotetramat-ketohydroxy and spirotetramat-MA-amide: 

Aerobic degradation/metabolism in four soils (20 °C, [3-14C] and [5-14C]) label) - full study details are 

given under B.8.1.1.1 (Babczinski, 2006b) 

• Methoxycyclohexanone (photolytic metabolite): Aerobic degradation in three soils (20 °C) 

Reference: Kinetic Evaluation of Laboratory Soil Degradation Studies of BYI08330-Enol, 

BYI08330-Ketohydroxy, BYI08330-MA-Amide 

Author(s), year: Roepke, B., 2006a 

Study/Report number: M-277178-03-1, MEF-06/199, amended 23.08.2007 

Guideline(s): FOCUS guidelines (FOCUS, 2000 and FOCUS, 2006) for kinetics modelling were 

considered 

GLP: Calculations - not applicable 

Validity: Study considered acceptable 

Material and methods:

The aerobic soil degradation study with spirotetramat-enol (Babczinski, 2006b) was used to estimate kinetic 

parameters and half-lives of spirotetramat metabolites spirotetramat-enol, spirotetramat-ketohydroxy and 

spirotetramat-MA-amide. It was not possible to get adequate formation fractions from the parent degradation 

study since under acidic extraction conditions, which was needed for spirotetramat but was not applicable for 

spirotetramat-enol, spirotetramat-enol was found to be partly unstable. For this reason a separate study with 

spirotetramat-enol was conducted. 

In the course of the spirotetramat-enol degradation study spirotetramat-enol showed a biphasic kinetic

behaviour, whereas in the first phase (during one day) more than 80 % of AR “has degraded”. In the second 

phase a much slower degradation was shown (during 118 days from 10.7 – 17.2 % of AR to 2.7 – 6.1 % of 

AR, mean of both labels). 

The degradate spirotetramat-ketohydroxy was built up to a maximum of 24.0 % of AR at DAT-1 (mean of 

both labels) and spirotetramat-MA-amide reached a maximum of 5.2 % of AR (mean of both labels). 

For moisture normalization procedure the appropriate moisture normalization factor was calculated: 
– 60 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.2.3-1: Normalization factors for soil moisture (fMoist). 

Moisture content 

during study 

[g 100 g-1] 

Moisture content 

at pF2 

[g 100 g-1]c

fMoist

Soil Soil texture (USDA) Study moisture MWHC [g 100 g-1]a Moisture content at pF 2.5b [g 100 g-1] Θ Θref 7.0 Moist f   ΘΘ = ref

‘Molino’ Sandy loam 80 % of MC at pF2.5 (27) 15 12.0 19 0.72 ‘Laacherhof AXXa’ Sandy loam 60 % of MWHC 27 (15) 16.2 19 0.89 ‘Laacherhof AIII’ Silt loam 60 % of MWHC 32 (21) 19.2 26 0.81 ‘Hoefchen’ Silt 60 % of MWHC 31 (21) 18.6 27 0.77 a MWHC for classified soils taken from the FOCUS report (FOCUS, 2000) b Estimates for classified soils taken from the FOCUS report (FOCUS, 2000) c Estimates for classified soils taken from the FOCUS report (FOCUS, 2000)
– 61 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

All values (both labels singular) measured were used for kinetic evaluation except of one outlier identified for 

spirotetramat-enol in soil AIII at DAT-4 (both labels). Samples with non-detects (nd) were set to 0.5 LOD. 

Samples marked with < LOQ were also set to 0.5 (LOQ + LOD). 

During sampling processing (starting with an aqueous extraction) spirotetramat-enol degradation started and 

directly after application oxidation yielded to spirotetramat-ketohydroxy in amounts of up to 4.9 and 3.3 % of 

AR ([3-14C] and [5-14C] label). It was shown in stability tests that 79.8 % to 90.1 % of HPLC-injected RA for 

the [3-14C] labelled test item and 85.7 % to 91.5 % for the [5-14C] labelled test item were obtained during 

aqueous DAT-0 extraction. To consider the ongoing degradation directly at application and extraction 

procedure an additional DAT-0 was introduced for modelling purposes assuming 100 % of AR for 

spirotetramat-enol and 0 % of AR for spirotetramat-ketohydroxy and spirotetramat-Ma-amide. Consequently, 

this approach led to four DAT-0 values for the parent and the metabolites, i.e. two measured ones and two 

fixed to 100.0 % of AR (parent) and 0.0 % of AR (metabolites), which were taken into account for modelling. 

Beside of single first order models (SFO, single first order; FOMC, first order multi compartment; and DFOP, 

double first order in parallel) a single first order reversible binding model (SFO-RB, a bi-phasic model 

consisting of two compartments, an unprotected compartment where application and degradation occurs and 

a protected compartment assuming no degradation, FOCUS, 2006) was considered to most adequately 

describe the degradation behaviour of metabolite spirotetramat-enol. The metabolites spirotetramatketohydroxy and spirotetramat-MA-amide were assumed to follow SFO kinetics, only. No weighting of the 

data was performed. As default value, free fitting of the initial parent amount and fixing amount to zero for 

metabolites and equal weighting was used. 

As the SFO-RB model is conceptually similar to the kinetic desorption model implemented in PEARL, 

required sorption and degradation parameter can be directly taken from the SFO-RB parameters: 

Pearl SFO-RB

Kt

 k1

kd k3

φ k2/k3

The parameter φ is not a PEARL input parameter per se, the corresponding input parameter is fne. As 

outlined in FOCUS (2006), the fne value can be deduced from φ as follows: 

L EQ

L EQ

ne K

K

f

,

,

⋅

+ ⋅

=

ρ

θ ρ

φ , 

whereby θ is the volumetric water content of the soil [g g-1] and ρ is the bulk density [g cm-3] (data available 

from the laboratory degradation rate study, Babczinski, 2006b). In case of spirotetramat-enol, the KL,EQ 

[L kg-1] is related to the Kd value obtained in the column leaching study using spirotetramat-enol as parent 

(Babczinski, 2006c). 

The proposed metabolic route of spirotetramat-enol in soil was converted to a four-compartment model 

(assuming SFO, FOMC or DFOP kinetics for the degradation of spirotetramat-enol and SFO kinetics for the 

degradation of spirotetramat-ketohydroxy and spirotetramat-MA-amide) and a five-compartment model 

(assuming SFO-RB kinetic model for spirotetramat-enol and SFO kinetics for spirotetramat-ketohydroxy and 

spirotetramat-MA-amide). 
– 62 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Figure B.8.1.2.3-1: Four-compartment model for fitting spirotetramat-enol (following SFO, FOMC or 

DFOP kinetics), spirotetramat-ketohydroxy (always SFO kinetics) and spirotetramat-MA-amide 

(always SFO kinetics) residues in soil. 

Figure B.8.1.2.3-2: Five-compartment model for fitting spirotetramat-enol (following SFO-RB 

kinetics), spirotetramat-ketohydroxy (SFO) and spirotetramat-MA-amide (SFO) residues in soil. 

The appropriate kinetic model was identified by following the approach recommended by FOCUS (2006) and

was based on visual inspection and the scaled error ε = σ / y. 

The goodness of fit was assessed by visual inspection and an error criterion based on a chi-square (χ

2

) test. 

A t-test was employed to identify the probability that a parameter is not significantly different from zero. The 

coefficients of determination r2 were also reported for comparative reasons. The kinetics modelling tool is 

built within MatLab (Vers. 7.0.4). The tool uses internal routines (Levenberg-Marquardt) of MatLab to 

optimize the model parameters to fit a chosen kinetics model to the metabolism study data. 

Findings:

In a first step, considering the evaluation of modelling and trigger endpoints, SFO kinetics was fitted to all 

unmodified data. The visual inspection and the scaled error ε with a range from 20.9 – 37.4 % for 

spirotetramat-enol, 24.2 – 42.4 % for spirotetramat-ketohydroxy and 29.3 – 43.8 % for spirotetramat-MA-
– 63 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

amide indicated that the SFO kinetic model was not the appropriate kinetic model. Further, the t-test 

probability of 0.25 for spirotetramat-MA-amide was not acceptable. 

Therefore, bi-phasic models such as FOMC and DFOP were tested for spirotetramat-enol. The statistical 

results and the visual inspection of the fits demonstrated that the FOMC fits represented a relatively

appropriate kinetic model to describe the dissipation of the test item (chi2 scaled-error values in the range of 

5.6 – 19.0 % for spirotetramat-enol (FOMC), 15.2 – 28.3 % for spirotetramat-ketohydroxy (SFO) and 29.1 – 

45.3 % for spirotetramat-MA-amide (SFO)). The bi-exponential model DFOP was checked for the test item 

and was found to lead to an improved fit. The respective chi2 scaled-error values ranged from 2.4 – 5.6 % for 

spirotetramat-enol (DFOP), 19.2 – 36.8 % for spirotetramat-ketohydroxy (SFO) and 28.5 – 41.8 % for 

spirotetramat-MA-amide (SFO). Moreover the visual inspection of the fits demonstrated that the DFOP fits 

represented the most appropriate kinetic model for the spirotetramat-enol dissipation in the four soils. 

Using the DFOP model, DT50 values of spirotetramat-enol (best fit kinetic) in the four soils tested range from 

0.02 – 0.18 days (non-normalized data). The DT90 values in the four soils range from 10.9 – 40.9 days 

(summarized in Table B.8.1.2.3-2). 

Table B.8.1.2.3-2: Best fit DT50 and DT90 values [days] of spirotetramat-enol based on DFOP kinetics 

(non-normalized data). 

Soil DT50

[days] 

DT90

[days] 

DT50recalc

a

[days] χ

2

 error [%] t-probability 

‘Molino’ 0.06 28.9 8.7 5.5 < 0.001 

‘Laacherhof AXXa’ 0.02 40.9 12.3 5.6 < 0.001 

‘Laacherhof AIII’ 0.18 16.8 5.1 2.4 < 0.001 

‘Hoefchen’ 0.02 10.9 3.3 5.2 < 0.001 

a

 SFO-DT50 recalculated from the DFOP-DT90 divided by 3.32. 

For the estimation of modelling parameters the SFO-RB model was tested and was found to be the most 

suitable kinetic model which fitted the analyzed dataset best. Spirotetramat-enol is rapidly degraded in the 

equilibrium domain but also rapidly transferred into a stronger bound soil compartment (‘protected 

compartment’), where it is not susceptible to degradation and only slowly transferred back into the 

equilibrium domain from which it degrades to spirotetramat-ketohydroxy following SFO kinetics. The visual 

assessments and the calculated scaled errors indicated acceptable fits. The range of the chi2 error is 6.4 –

11.0 % for spirotetramat-enol (SFO-RB), 17.7 – 33.8 % for spirotetramat-ketohydroxy (SFO) and 27.4 – 

40.0 % for spirotetramat-MA-amide (SFO). From the scaled error and visual assessment the fits are 

excellent for spirotetramat-enol and altogether acceptable for spirotetramat-ketohydroxy and spirotetramatMA-amide. The t-test probability is < 0.001 for spirotetramat-enol and spirotetramat-ketohydroxy and ranged 

from < 0.001 – 0.029 for spirotetramat-MA-amide, indicating that all parameters are significant (p < 0.05). 

The DT50/90 values were calculated from optimized first-order rate constants and were normalized to the soil 

moisture at field capacity using estimated moisture correction factors (see Table B.8.1.2.3-1). The 

normalized DT50 values ranged from 0.02 – 0.13 days for spirotetramat-enol, from 1.2 – 12.1 days for 

spirotetramat-ketohydroxy and from 0.2 – 3.9 days for spirotetramat-MA-amide (summarized in Table 

B.8.1.2.3-7). 

As the estimated biphasic SFO-RB half-lives of spirotetramat-enol are not applicabel to be used for e.g. 1st

tier PECSoil and PECSW model approaches (EU risk assessment) the recalculated DT50 value from the DT90

value of the biphasic FOMC model (SFO-DT50 = FOMC-DT90 / 3.32) is suggested for modelling purposes. 

The visual assessments of the FOMC fits were acceptable and the calculated scaled chi2 errors ranged from 

5.6 – 19 % for spirotetramat-enol. 

The kinetic evaluations for all four soils are summarized in the tables B.8.1.2.3-3 to B.8.1.2.3.-6. 
– 64 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.2.3-3: Kinetic evaluation of the spirotetramat-enol degradation study based on 

SFO  SFO  SFO kinetics for spirotetramat-enol, spirotetramat-ketohydroxy and spirotetramat-MAamide, respectively. 

Compound Kinetics Parameter ‘Molino’ ‘Laacherhof 

AXXa’ 

‘Laacherhof 

AIII’ ‘Hoefchen’ 

DT50 [days] 0.098 0.022 0.22 0.020 

DT50 norma [days] 0.068 0.017 0.16 0.013 

DT90 [days] 0.33 0.072 0.73 0.066 

χ

2

 error [%] 28.8 37.4 20.9 31.3 

R

2

 0.98 0.98 0.98 0.99 

Spirotetramatenol SFO 

t-probability < 0.001 < 0.001 < 0.001 < 0.001 

DT50 [days] 16.6 4.14 4.87 1.49 

DT50 norma [days] 12.0 3.68 3.94 1.15 

DT90 [days] 55.1 13.8 16.2 4.93 

Formation fraction [0 ... 1] 0.19 0.19 0.33 0.22 

χ

2

 error [%] 31.1 24.2 37.8 42.4 

R

2

 0.79 0.93 0.86 0.86 

Spirotetramatketohydroxy SFO 

t-probability 0.010 0.022 < 0.001 0.017 

DT50 [days] 5.32 1.09 1.76 0.30 

DT50 norma [days] 3.83 0.97 1.43 0.23 

DT90 [days] 17.7 3.62 5.86 0.99 

Formation fraction [0 ... 1] Fixed to 1.0 during kinetic evaluation 

χ

2

 error [%] 33.8 29.3 37.5 43.8 

R

2

 0.76 0.86 0.89 0.82 

SpirotetramatMA-amide SFO 

t-probability 0.18 0.22 0.04 0.25 

a

 DT50 normalized to 20 °C and 100 % FC (pF2). 
– 65 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.2.3-4: Kinetic evaluation of the spirotetramat-enol degradation study based on 

FOMC  SFO  SFO kinetics for spirotetramat-enol, spirotetramat-ketohydroxy and spirotetramatMA-amide, respectively. 

Compound Kinetics Parameter ‘Molino’ ‘Laacherhof 

AXXa’ 

‘Laacherhof 

AIII’ ‘Hoefchen’ 

DT50 [days] 0.060 0.018 0.12 0.016 

DT90 [days] 3.64 9.78 5.81 2.63 

DT50recalc

a

 [days] 1.10 2.95 1.75 0.79 

DT50recalc normab [days] 0.80 2.64 1.42 0.61 

alpha 0.4116 0.2594 0.4374 0.3235 

beta 0.0136 0.0014 0.0302 0.0021 

χ

2

 error [%] 18.97 16.0 5.6 16.9 

R

2

 0.97 0.97 0.99 0.98 

Spirotetramatenol FOMC 

t-probability nc nc nc nc 

DT50 [days] 11.7 3.5 4.6 1.3 

DT50 normb [days] 8.5 3.1 3.7 1.0 

DT90 [days] 38.9 11.8 15.3 4.4 

Formation fraction [0 ... 1] 0.22 0.24 0.35 0.27 

χ

2

 error [%] 22.5 15.2 16.8 28.3 

R

2

 0.90 0.98 0.96 0.92 

Spirotetramatketohydroxy SFO 

t-probability nc nc nc nc 

DT50 [days] 3.2 0.9 1.7 0.3 

DT50 normb [days] 2.3 0.8 1.4 0.2 

DT90 [days] 10.8 3.0 5.5 0.8 

Formation fraction [0 ... 1] Fixed to 1.0 

χ

2

 error [%] 39.4 29.1 38.0 45.3 

R

2

 0.71 0.87 0.88 0.75 

SpirotetramatMA-amide SFO 

t-probability nc nc nc nc 

a

 SFO-DT50 recalculated from FOMC-DT90 divided by 3.32. 

b

 DT50 normalized to 20 °C and 100 % FC (pF2). 
– 66 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.2.3-5: Kinetic evaluation of the spirotetramat-enol degradation study based on 

DFOP  SFO  SFO kinetics for spirotetramat-enol, spirotetramat-ketohydroxy and spirotetramatMA-amide, respectively. 

Compound Kinetics Parameter ‘Molino’ ‘Laacherhof 

AXXa’ 

‘Laacherhof 

AIII’ ‘Hoefchen’ 

DT50 [days] 0.06 0.02 0.18 0.02 

DT90 [days] 28.9 40.9 16.8 10.9 

DT50recalc

a

 [days] 8.7 12.3 5.1 3.3 

DT50recalc normab [days] 6.3 10.9 4.1 2.5 

k1 [days-1] 15.7 40.5 5.20 41.8 

k2 [days-1] 0.011 0.0098 0.030 0.011 

g

c

 [%] 0.86 0.85 0.83 0.89 

χ

2

 error [%] 5.54 5.6 2.4 5.2 

R

2

 0.99 0.99 0.99 0.99 

Spirotetramatenol DFOP 

t-probability < 0.001 < 0.001 < 0.001 < 0.001 

DT50 [days] 16.7 4.2 5.1 1.5 

DT50 normb [days] 12.1 3.8 4.1 1.2 

DT90 [days] 55.6 13.8 16.9 5.0 

Formation fraction [0 ... 1] 0.21 0.22 0.36 0.24 

χ

2

 error [%] 24.2 19.2 28.8 36.8 

R

2

 0.86 0.96 0.9 0.89 

Spirotetramatketohydroxy SFO 

t-probability < 0.001 < 0.001 < 0.001 < 0.001 

DT50 [days] 5.5 1.1 1.9 0.3 

DT50 normb [days] 4.0 1.0 1.5 0.2 

DT90 [days] 18.1 3.6 6.3 1 

Formation fraction [0 ... 1] Fixed to 1.0 

χ

2

 error [%] 30.8 28.5 30.9 41.8 

R

2

 0.77 0.87 0.91 0.82 

SpirotetramatMA-amide SFO 

t-probability 0.005 < 0.001 0.001 0.029 

a

 SFO-DT50 recalculated from DFOP-DT90 divided by 3.32. 

b

 DT50 normalized to 20 °C and 100 % FC (pF2). 

c

 g denotes the size [0 ... 1] of the fast degrading fraction. 
– 67 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.2.3-6: Kinetic evaluation of the spirotetramat-enol degradation study based on 

SFO-RB  SFO  SFO kinetics for spirotetramat-enol, spirotetramat-ketohydroxy and spirotetramatMA-amide, respectively. 

Compound Kinetics Parameter ‘Molino’ ‘Laacherhof 

AXXa’ 

‘Laacherhof 

AIII’ ‘Hoefchen’ 

C0 100.6 100.3 96.2 100.7 

k1 2.786 7.701 1.548 9.032 

k2 2.145 6.045 0.859 4.701 

k3 0.013 0.012 0.037 0.012 

k4 0.041 0.166 0.136 0.456 

k5 0.127 0.632 0.365 2.222 

k6 10.762 26.780 2.798 28.982 

Rates in the 

overall model - 

k1 + k6 13.547 34.481 4.346 37.114 

DT50

a

 [days] 0.05 0.02 0.16 0.02 

DT50 normb [days] 0.04 0.02 0.13 0.02 

DT90 [days] 0.17 0.07 0.53 0.06 

χ

2

 error [%] 6.75 6.8 10.98 6.36 

R

2

 0.997 0.997 0.993 0.996 

t-probability < 0.001 < 0.001 < 0.001 < 0.001 

KLin eq

c

 0.790 0.540 0.780 0.700 

Spirotetramatenol SFO-RB 

fne

d

 193.2 693.1 28.9 593.7 

DT50 [days] 16.7 4.2 5.1 1.5 

DT50 normb [days] 12.1 3.8 4.1 1.2 

DT90 [days] 55.6 13.9 16.9 5.1 

Formation fraction [0 ... 1] 0.21 0.22 0.36 0.24 

χ

2

 error [%] 22.3 17.7 27.2 33.8 

R

2

 0.859 0.956 0.874 0.889 

Spirotetramatketohydroxy SFO 

t-probability < 0.001 < 0.001 < 0.001 < 0.001 

DT50 [days] 5.4 1.1 1.8 0.3 

DT50 normb [days] 3.9 1.0 1.5 0.2 

DT90 [days] 18.1 3.6 6.3 1 

Formation fraction [0 ... 1] Fixed to 1.0 during kinetic evaluation 

χ

2

 error [%] 29.6 27.4 29.6 40 

R

2

 0.771 0.866 0.913 0.823 

SpirotetramatMA-amide SFO 

t-probability 0.0047 < 0.001 0.001 0.029 

a

 DT50 resulting from sum of degradation rates k1 and k6 

b

 DT50 normalized to 20 °C and 100 % FC (pF2). 

c

 KLin eq = linearised sorption coefficient (FOCUS, 2006), equivalent to the Kd value obtained in the column leaching study (Babczinski, 

2006c) 

d

 fne = factor for describing the ratio between the equilibrium and non-equilibrium Freundlich coefficients (FOCUS, 2006) 
– 68 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Conclusion:

The kinetic evaluation of the aerobic soil degradation of the metabolites spirotetramat-enol, spirotetramatketohydroxy and spirotetramat-MA-amide was performed according to the FOCUS (2006) recommendations. 

Spirotetramat-enol, main metabolite of spirotetramat, spirotetramat-ketohydroxy and spirotetramat-MA-amide 

degraded quickly and are expected not to accumulate in soil. 

Table B.8.1.2.3-7: Summary on normalized DT50 values of spirotetramat-enol, spirotetramatketohydroxy and spirotetramat-MA-amide according to the SFO-RB  SFO  SFO modelling 

approach (best fit model). 

DT50 normalized to 20°C and pF2 

Spirotetramat-enol 

(SFO-RB) 

Spirotetramatketohydroxy 

(SFO) 

SpirotetramatMA-amide 

(SFO) Soil 

DT50 norm 

[days] fne [0 ... 1] kd

a

 [days-1] DT50 norm 

[days] 

DT50 norm 

[days] 

‘Molino’ 0.04 193.2 0.013 12.1 3.9 

‘Laacherhof AXXa’ 0.02 693.1 0.012 3.8 1.0 

‘Laacherhof AIIII’ 0.13 28.9 0.037 4.1 1.5 

‘Hoefchen’ 0.02 593.7 0.012 1.2 0.2 

a

 kd (PEARL) = k3 (SFO-RB) 

Reviewer comments:

• Outlier (spirotetramat-enol, in soil Laacherhof AIII, DAT-4) removed was not justified in the original 

report (Babczinski, 2006b), but is accepted by the reviewer. 

• It was accepted by the reviewer that only the spirotetramat-enol study was considered relevant for 

the degradation kinetics calculations of the spirotetramat metabolites. In a qualitative consistency 

check (simulated degradation of spirotetramat and its metabolites using the derived kinetic parameter 

set plotted against the measured data for the spirotetramat-parent study) it was shown that the 

simulated results appeared to be plausible in relation to the measured data also in the spirotetramat 

degradation study. However, comparatively high residuals especially in case of spirotetramatketohydroxy and spirotetramat-MA-amide demonstrated that due to the analytical bias of the 

metabolite data these fits should not be used quantitatively. 

• Beside the SFO-RB approach, the DFOP kinetics is the ‘best fit’ model for the degradation of 

spirotetramat-enol. However, the notifier derived 1st tier SFO-DT50 values for spirotetramat-enol from 

FOMC kinetics (recalculated from the FOMC-DT90). Following the FOCUS kinetic report, recalculated

SFO-DT50 should be based on FOMC kinetics, if i) FOMC kinetics yields a sufficient fit to the 

measured data and ii) if less than 10 % of the parent (spirotetramat-enol) remains by study 

termination. Therefore, the approach suggested by the notifier is accepted by the reviewer. 
– 69 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Reference: [Carbonyl-14C]-4-Methoxycyclohexanone: Aerobic Soil Degradation in Three 

Soils 

Author(s), year: Dehner, D., Heinemann, O., 2006 

Study/report number: M-269022-02-2, MEF-05/485, amended 18.07.2006 

Guideline(s): EPA Guideline for Aerobic Soil Metabolism, Subdivision N, Section 162-1, 

EC-Directive 91/414/EEC Annex I Part 7 and Annex II Part 9, 

OECD Guideline 307: Aerobic and Anaerobic Transformation in Soil (2002) 

GLP: Yes 

Deviations: None 

Validity: Study considered acceptable 

Material and methods:

Test substance: [Carbonyl-14C]-4-methoxy-cyclohexanone (CAS name: cyclohexanone, 4-

methoxy); sample ID: BECH 1831 (reference synthesis: KML 3292-3), specific 

activity: 4.71 MBq mg-1 (= 127.31 μCi mg-1); radiochemical purity: 97.0 % (acc. 

radio-HPLC); Chemical purity: 96.9 % (GC-FID) 

Reference substances: [Carbonyl-14C]-4-methoxycyclohexanone, no other reference items were used 

Test system: Static incubation test system 

Acclimatisation time: 5 days 

Test conditions: Aerobic conditions were maintained. Moisture adjusted soils (55 % MWHC) were 

placed in the dark at 20 °C. At DAT-0 the absolute microbial biomass carbon 

contents corresponded to 0.5 %, 2.6 % and 3.2 % relative to the soil organic 

carbon content of the soils ‘Molino’, ‘Laacherhof AIII’ and ‘Hoefchen’, respectively. 

Number of replications: Duplicate samples 

Test duration: Soil ‘Hoefchen’ and ‘Laacherhof AIII’: 14 days 

Soil ‘Molino’: 3 days (because of the fast degradation observed in the EU soils) 

Sampling intervals: Soil ‘Hoefchen’ and ‘Laacherhof AIII’: 0 (approx. 1 h after treatment), 1, 3, 7 and 

14 days 

Soil ‘Molino’: 0 (approx. 1 h after treatment), 3 h, 7 h, 1, 2 and 3 days 

Application: 0.133 mg ai kg-1 dry soil (nominal) equivalent to 50 g ai ha-1 (nominal, calculation 

based on homogeneous distribution for 2.5 cm soil depth and 1.5 g/cm3 soil 

density), supplied test item was dissolved in water and drop wise applied to the 

soil surface. No instability in the stock solution was observed. 

Analyses: All soil samples were extracted directly at the day of sampling. 

Extraction Procedure EU soils:

Extraction was done by shaking three times at room temperature with 80 mL of 

acetonitrile/water/formic acid (100/100/0.5, v/v/v), then twice with 80 mL of 

acetonitrile/1 M aqueous HCl (1/1, v/v) and once with 80 mL of pure acetonitrile, 

using a mechanical shaker. 

Due to unforeseen radioactivity losses the extraction procedure was changed at 

the last two sampling days (DAT-7 and DAT-14): The first extraction was done by 

shaking twice with 80 mL of acetonitrile/1 M aqueous HCl (1/1, v/v) in the test 

flask fitted with a trap for volatiles. After each shaking period the test flasks were 

placed into a desiccator to transfer 14CO2 into the trap (at day 7 a new trap for 

volatiles was placed on the test flask). Soils were further extracted by three cycles 

with 80 mL of acetonitrile/water/formic acid (100/100/0.5, v/v/v), one cycle with 80 

mL of acetonitrile/1 M aqueous HCl (1/1, v/v) and once with 80 mL pure 

acetonitrile, using a mechanical shaker. 

Extraction Procedure US soil:
– 70 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

80 mL of acetonitrile/1 M aqueous HCl (1/1, v/v) were poured into the incubation 

system fitted with a trap for volatiles. After each shaking period the test flasks 

were placed into a desiccator to transfer 14CO2 into the trap. Soils were further 

extracted by one cycle with 80 mL of acetonitrile/1 M aqueous HCl (1/1, v/v), three 

cycles with 80 mL of acetonitrile/water/formic acid (100/100/0.5, v/v/v) and one 

cycle with 80 mL pure acetonitrile, using a mechanical shaker. 

The combined extractable residues were radio-assayed by LSC and analyzed by 

reversed-phase HPLC (HPLC-flow-through 14C-radioactivity detection), with 

exemplary result verification in normal phase TLC (TLC-14C-phosphor-imaging). 

In order to determine the non-extractable soil residues air-dried extracted soils 

and paper filters were combusted and 14C levels were measured using LSC. 

Volatile traps: Static volatile trap attachment for CO2 (soda lime) and organic volatiles 

(polyurethane foam), permeable for oxygen (identification of 14C as 14CO2 by 

BaCO3-precipation) 

Analytical techniques: LSC, RP-HPLC, Si-60 silica TLC, LC-MS 

Detection limits: LSC: for raw extracts LOQ ≤ 0.55 % of AR, for combustion LOQ ≤ 0.05 % of AR; 

for CO2 samples LOQ < 0.01 % of AR; HPLC: LOD = 0.9 % of AR, LOQ was set 

to three times the LOD: 2.7 % of AR. TLC: LOD = 1.5 % of AR, LOQ was set to 

three times the LOD: 4.5 % of AR 

Kinetic evaluation: SFO and FOMC kinetics, MatLab vers. 7.0.4.365; values < LOD were set to 0.5 

LOD. Values between LOD and LOQ were set to the measured values. 

Table B.8.1.2.3-8: Main soil properties. 

Property ‘Hoefchen’ ‘Laacherhof AIIIa’ ‘Molino’ 

Location Germany/Burscheid Germany/Monheim USA/Pensacola 

Texture (USDA) Silt loam Loam Loamy sand 

Soil taxonomic classification (USDA) Loamy, mixed, mesic 

Typic Argudalfs 

Loamy, mixed, mesic 

Typic Argudalfs 

Fine-loamy, kaolinitic, 

thermic Plinthic 

Kandiudults 

SCS soil series Alfisols, Udalfs Alfisols, Udalfs Ultisol 

Sand (USDA) [%] 29.0 43.0 78.4 

Silt (USDA) [%] 52.0 34.0 14.5 

Clay (USDA) [%] 19.0 23.0 7.1 

pH (H2O) 6.8 7.0 6.7 

pH (CaCl2) 6.5 6.6 5.9 

pH (saturated paste) 6.9 7.0 6.4 

Organic mattera [%] 4.1 1.7 1.2 

Organic carbon [%] 2.4 1.0 0.7 

CEC [meq/100 g DM] 12.8 9.3 5.0 

Moisture content [g/100 g DM] 

 MWHC 

 WHC at 1/3 bar 

65.0 

20.6 

45.1 

13.0 

34.6 

8.8 

Biomassb [mg microbial C/kg soil DM] start DAT-0: 756 DAT-0: 260 DAT-0: 32 

Biomassb [mg microbial C/kg soil DM] end DAT-14: 670 DAT-59: 270 DAT-3: N/A 

a

 Organic C = organic matter / 1.724 

b

 Substrate induced respiration 

N/A not applicable 
– 71 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Findings:

All values are given as mean values of the replicates. 

The material balances ranged from 71.3 % to 97.8 % of AR for ‘Hoefchen’ soil, from 70.4 % to 99.0 % for 

‘Laacherhof AIII’ soil and from 95.4 % to 99.7 % of AR for ‘Molino’ soil, respectively. According to the study 

authors the losses of radioactivity in soils ‘Hoefchen’ and ‘Laacherhof’ at days 1 and 3 was caused by

liberation of 14CO2 bound in the soil during the extraction procedure using acidic solvent. Therefore the 

following extraction procedure was changed whereas the first extraction step was performed with test 

systems closed with a soda lime trap. It was shown that the following balances were found > 96 % of AR. 

In all three tested soils a high release of 14CO2 was observed reaching levels up to 74.1 %, 75.8 % and 

66.3 % of AR (in soils ‘Hoefchen’, ‘Laacherhof AIII’ and ‘Molino’, respectively) at study termination. No 

significant amounts (< 0.2 % of AR) of other volatile compounds were detected. 

A rapid decrease of extractable residues occurred during the first incubation days in soils ‘Hoefchen’ and 

‘Laacherhof AIII’ (‘Hoefchen’/’Laacherhof AIII’: from 97.1/98.6 % of AR at DAT-0 to 6.6/8.6 % of AR at DAT1). In soil ‘Molino’ the decrease was considerably slower than in the European soils. 

All transformation products observed were minor which amounts did not exceed 5 % of AR. 

The portion of non-extractable radioactivity rapidly increased reaching its peaks at levels of 22.6 to 24.9 % of 

AR after one to two days after application. A slight decrease in NER until study termination was observed. 

The laboratory half-live of 4-methoxy-cyclohexanone in the European soils was < 1 day. It was not possible 

to calculate statistical DT50/90 values due to the fast dissipation and insufficient data points. For soil ‘Molino’ a 

DT50 of 0.6 days and a DT90 of 1.8 days was calculated according to simple first order kinetics. 

Table B.8.1.2.3-9: Distribution and recovery of applied radioactivity [% of AR] after application of 

[carbonyl-14C]-4-methoxy-cyclohexanone to three soils (mean of duplicate samples). 

Soil DAT Extractable CO2 NER Total 

0 97.1 na 0.7 97.8 

1 6.6 39.7 24.9 71.3 

3 4.5 55.1 22.6 82.3 

7 3.9 70.1 22.3 96.3 

‘Hoefchen’ 

14 3.2 74.1 20.2 97.5 

0 98.6 na 0.4 99.0 

1 8.6 37.4 24.3 70.4 

3 5.0 49.7 22.6 77.5 

7 4.1 72.8 20.9 97.8 

‘Laacherhof 

AIIIa’ 

14 3.2 75.8 19.6 98.6 

0 99.5 na 0.2 99.7 

0.13 94.9 2.9 1.6 99.3 

0.29 82.1 10.4 4.8 97.2 

1 31.9 46.6 18.3 96.8 

2 10.8 62.0 22.6 95.4 

‘Molino’ 

3 12.2 66.3 18.9 97.4 

na denotes not analysed 
– 72 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.2.3-10: Characterization of extractable radioactivity [% of AR] after application of 

[carbonyl-14C]-4-methoxy-cyclohexanone to three soils (individual replicates). 

4-Methoxycyclohexanone ROI 1 ROI 2 ROI 3 ROI 4 Soil DAT 

A B A B A B A B A B 

0 92.1 96.3 3.0 2.8 nd nd nd nd nd nd 

1 nd 0.9 nd nd 2.0 2.0 1.0 1.0 2.8 2.7 

3 nd nd nd nd nd nd 1.4 1.4 3.2 3.1 

7 nd nd nd nd nd nd 1.8 0.9 2.1 2.9 

‘Hoefchen’

14 nd nd nd nd nd nd 1.4 nd 1.6 2.6 

0 99.6 97.7 nd nd nd nd nd nd nd nd 

1 nd 1.0 nd nd 3.3 2.6 1.4 1.2 3.2 4.0 

3 nd nd nd nd nd nd 1.5 1.4 3.5 3.7 

7 nd nd nd nd nd nd 2.1 1.0 2.0 3.1 

‘Laacherhof 

AIIIa’

14 nd nd nd nd nd nd nd 1.6 2.5 1.6 

0 98.4 100.6 nd nd nd nd nd nd nd nd 

0.13 94.3 95.5 nd nd nd nd nd nd nd nd 

0.29 81.5 82.7 nd nd nd nd nd nd nd nd 

1 23.1 22.3 nd nd 4.4 4.7 nd nd 3.6 2.9 

2 3.9 3.6 nd nd 2.7 2.6 nd nd 3.7 3.5 

‘Molino’

3 8.8 2.4 nd nd 2.4 2.5 nd nd 4.3 2.4 

nd denotes not determined 

Table B.8.1.2.3-11: Calculated DT50 and DT90 of [carbonyl-14C]-4-methoxy-cyclohexanone in three 

soils using SFO and FOMC kinetics. 

SFO Soil 

DT50 [days] DT90 [days] Best fit model, χ

2

 error 

‘Hoefchen’ < 1 < 1 not evaluateda

‘Laacherhof’ < 1 < 1 not evaluateda

‘Molino’ 0.6 1.8 SFO, 11.2 % 

a

For the European soils no statistical DT50 /DT90 values were calculated due to the very short dissipation and therefore the lack of data 

points after the treatment.

Conclusion:

The photolysis metabolite 4-methoxy-cyclohexanone degrades very quickly in all three tested soils under 

aerobic conditions. The half-live is < 1 day. No major degradates (≥ 5 % of AR) were detected. The major 

transformation product was 14CO2 formed with maximum amounts of 66.3 % to 75.8 % of AR at study 

termination. The NER fraction increased fast to its peak level up to ~25 % of AR in soils ‘Hoefchen’ and 

‘Laacherhof AIII’ and 23 % of AR in soil ‘Molino’. At study termination the NER declined to ≤ 20 % of AR. No 

volatile organic compounds were formed during the incubation time. 

Reviewer comments:

• Microbial biomass carbon content in ‘Molino’ soil is rather low (corresponding to 0.5 % of total carbon 

content). According to the OECD guideline 307 the microbial biomass of at least 1 % of total organic 

carbon is recommended. 
– 73 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

B.8.1.2.4 Anaerobic degradation rate of the active substance (OECD Annex IIA, 7.2.4, IIIA, 9.1.2) 

The anaerobic degradation rate of spirotetramat was investigated in one study which was also used to 

elucidate the route of degradation under aerobic conditions: 

• Aerobic/anaerobic degradation in one soil (20 °C, [3-14C] label) 

Full details including degradation rates are given under B.8.1.1.2. 

B.8.1.2.5 Anaerobic degradation rate of relevant metabolites (OECD Annex IIA, 7.2.5) 

The anaerobic degradation rates of relevant metabolites of spirotetramat were investigated in one study 

which was also used to elucidate the route of degradation under aerobic conditions: 

• Aerobic/anaerobic degradation in one soil (20 °C, [3-14C] label) 

Full details are given under B.8.1.1.2. 
– 74 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

B.8.1.2.6 Summary on the rate of degradation in laboratory soil studies 

Note: In contrast to the EU risk assessment, the Canadian and US risk assessment is based on nonnormalized soil degradation rates, and deviating input data are used for calculation and modelling of 

predicted/expected environmental concentrations (e.g. the 80th percentile, or the 90th percentile of the 

confidence interval (C.I.) on the arithmetic mean, etc.). Respective values are stated in the summary tables 

together with the endpoints considered relevant for the EU risk assessment. 

The laboratory soil degradation rate of spirotetramat and metabolites was investigated in 3 EU soils and 1 

US soil with the following range of soil properties (pH, organic C, clay content) using [3-14C] labelled 

spirotetramat or [5-14C] and [3-14C] labelled spirotetramat-enol as parent. 

• pH (CaCl2) 5.4 – 6.7 

• organic C 0.93 – 2.1 % 

• clay content 5.0 – 12.0 % 

No degradation rates are available for more alkaline soil (with a pH > 7). However, degradation of 

spirotetramat was extremely fast in the pH range tested and no dependency on soil pH was observed. From 

hydrolysis behaviour it can be deduced that degradation of spirotetramat is likely to be even faster at higher 

pH values. In field studies conducted on 4 US soils with a pH range of 7.0 – 8.1 (pH measured in water, 

equivalent to approx. pH 5.5 – 7.3 in CaCl2), no dependence on soil pH was observed. In this respect, it is 

highly unlikely that degradation of spirotetramat under more alkaline conditions will significantly differ from 

degradation rates observed under more acidic conditions. 

Under aerobic conditions, spirotetramat was found to be a very fast degrading compound following 

biphasic degradation. Following best fit kinetics (i.e. double first order in parallel kinetics, DFOP), nonnormalized degradation half-life (DegT50) values of spirotetramat were in a range of 0.09 – 0.30 days (chi2

error ≤ 6.1 %); respective DegT90 was in a range of 0.34 – 1.26 days. Since most environmental models are 

not capable to handle DFOP kinetics, a conservative SFO-DegT50 for modelling may be derived from the 

DFOP-DegT90 divided by 3.32. This procedure results in a DegT50recalc in the range of 0.10 – 0.38 days. 

Applying SFO kinetics (chi2 error ≤ 21.8 % for one soil, for three soils chi2 error ≤ 9.5 %), non-normalized 

DegT50 values of spirotetramat were in a range of 0.08 – 0.33 days, respective DegT90 values were in a 

range of 0.28 – 1.09 days. Following normalization to 20 °C and pF2, obtained DegT50norm values were in a 

range of 0.05 – 0.23 days. 

The biodegradation of spirotetramat was additionally investigated in two soils under outdoor climatic 

conditions considered more realistic for the indented use (metabolism studies). In close agreement to the lab 

results, the parent compound was quickly degraded with a DT50 of 1.2 and 2.9 days (‘Laacherhof AIIIa’ and 

‘Molino’ soil, respectively, both SFO kinetics, R2

≥ 0.98). 

Owing to analytical reasons (instability of spirotetramat-enol during acidic extraction), degradation rates of 

the metabolites spirotetramat-enol, spirotetramat-ketohydroxy and spirotetramat-MA-amide were obtained

from the additional spirotetramat-enol laboratory degradation study, only. This study was conducted on the 

same soils that were used for the parent degradation study. However, a slightly alkaline extraction procedure 

was applied to ensure spirotetramat-enol stability during extraction. 

Similar to the parent, spirotetramat-enol dissipated following pronounced biphasic kinetics, with an 

extremely quick first phase and a significantly slower second phase. This extremely biphasic behaviour of 

spirotetramat-enol can be explained by an extensive oxidation of the compound leading either to formation of 
– 75 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

spirotetramat-ketohydroxy or to extensive binding to the soil matrix. The ‘nature’ of the extensive binding to 

the soil matrix is not fully understood, yet. However, binding of spirotetramat-enol to the soil matrix is partly 

reversible under conditions of extraction, releasing a fraction which mainly contributes to the second and 

slower phase of the biphasic degradation kinetics. Both processes (formation of spirotetramat-ketohydroxy 

and binding to the soil matrix) are considered to take place almost immediately once in contact with soil 

(under aerated conditions, oxidation process) and are likely to be competitive factors depending on the 

available oxygen. 

The best fit kinetic model for degradation of spirotetramat-enol is the DFOP model (chi2 error ≤ 5.6 %). This 

model yielded a DegT50 for spirotetramat-enol in the range of 0.02 – 0.18 days. Respective DegT90 values 

were in a range of 10.9 – 40.9 days. Since most environmental models are not capable to handle DFOP 

kinetics, a conservative SFO-DegT50 for modelling may be derived from the DFOP-DegT90 divided by 3.32. 

This procedure results in a DT50recalc in the range of 3.3 – 12.3 days. 

According to first order multi compartment (FOMC) kinetics, DegT50 values of spirotetramat-enol were in a 

range of 0.02 – 0.12 days (chi2 error ≤ 19.0 %), respective DegT90 values were in a range of 2.6 – 9.8 days. 

Similar to the DFOP kinetics, a conservative SFO-DegT50 for modelling may be derived from the FOMCDegT90 divided by 3.32. This procedure results in a DegT50recalc in the range of 0.8 – 3.3 days. Following 

normalization to 20 °C and pF2, SFO-DegT50recalc values were in a range of 0.6 – 2.6 days. Since residues of 

spirotetramat-enol were clearly < 10 % of AR by study termination, the normalized SFO-DegT50recalc deriving 

from FOMC kinetics is recommended by FOCUS as suitable and conservative parameter for 1st tier 

modelling if a higher tier approach (e.g. SFO-RB kinetics, see following test) is not applicable (EU risk 

assessment only). 

The highly specific degradation behaviour of spirotetramat-enol was considered to be adequately explained 

by a simple first order-reversible binding (SFO-RB) model, which is equivalent to the (non-equilibrium) kinetic 

sorption model in PEARL. In the SFO-RB model, (extractable) spirotetramat-enol is considered to consist of 

two fractions, one is mobile and degradable (to spirotetramat-ketohydroxy), the other fraction is tightly bound 

to the soil matrix (where it is protected against further degradation assuming zero degradation). Since 

binding to the soil matrix is considered reversible, a slow and steady re-transfer of bound spirotetramat-enol 

into the mobile and degradable spirotetramat-enol fraction is assumed. Degradation of the mobile fraction of 

spirotetramat-enol and transfer rates between mobile and bound fraction are considered to follow SFO 

kinetics. The re-transfer (desorption) rate of the immobile spirotetramat-enol into the mobile fraction is 

adequately reflected by the PEARL parameter kd (kinetic sorption rate constant, [days-1]), the ratio between 

immobilization and mobilization rates is mirrored by the PEARL parameter fne (ratio between non-equilibrium 

and equilibrium sorption sites, dimensionless). 

Consequently, residue data from the spirotetramat-enol degradation study were fitted to a multi-compartment 

model with spirotetramat-enol (parent) following SFO-RB kinetics and spirotetramat-ketohydroxy and 

spirotetramat-MA-amide linked in series (both following SFO kinetics). 

According to the SFO-RB approach, DegT50 of spirotetramat-enol (degradation of the mobile and 

degradable fraction) was in a range of 0.02 – 0.16 days (SFO kinetics, chi2

 error ≤ 11.0 %, R2≥ 0.99). The 

DegT50 of the transfer rate into the stronger bound fraction was estimated to be in a range of 0.11 – 0.18 

days, the DegT50 of the slow re-transfer back from the bound into the degradable fraction was in a range of 

18.7 – 57.8 days (the latter transfer rate is equivalent to the desorption rate, Kd, required for kinetic 

adsorption modelling in PEARL). From the ratio of the two transfer rates, the fne value can be deduced which 

is needed as further input value for kinetic adsorption modelling in PEARL. For spirotetramat-enol fne values 

were in a range of 29 – 693. Since formation fraction of spirotetramat-enol from the parent, i.e. spirotetramat, 

is not known, a worst case formation fraction of 100 % is assumed for environmental modelling purposes. 
– 76 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Additional modelling of a soil column study conducted on four soils (Babczinski, 2006c, Hammel, 2007),

based on a kinetic adsorption approach using the transport model HYDRUS (conceptual equivalent to 

PEARL) clearly demonstrated that the SFO-RB/kinetic adsorption approach adequately describes the 

behaviour of spirotetramat-enol observed in the column leaching experiments. 

Following the overall best-fit modelling approach (i.e. SFO-RB  SFO  SFO kinetics for spirotetramat-enol, 

spirotetramat-ketohydroxy and spirotetramat-MA-amide, respectively), degradation DegT50 of spirotetramatketohydroxy in soil was calculated to be in a range of 1.5 – 16.7 days (SFO kinetics, chi2

 error ≤ 33.8 %, R2

≥ 0.86). Respective DegT90 values were in a range of 5.1 – 55.6 days. Formation fraction of spirotetramatketohydroxy from its precursor, spirotetramat-enol, was calculated to be in a range of 20.6 – 35.6 % with an 

arithmetic mean of 25.7 %. Normalization to 20 °C and pF2 resulted in DegT50 values in a range of 1.2 – 

12.1 days. 

According to the SFO-RB  SFO  SFO kinetics approach, degradation DegT50 of spirotetramat-MAamide in soil was calculated to be in a range of 0.3 – 5.4 days (SFO kinetics, chi2

 error ≤ 40.0 %, R2≥ 0.77). 

Respective DegT90 was in a range of 1.0 – 18.1 days. Formation fraction of spirotetramat-MA-amide from its 

precursor, spirotetramat-ketohydroxy, was fixed to 100 % during fitting procedure. Normalization to 20 °C 

and pF2 resulted in DegT50 values in a range of 0.2 – 3.9 days. 

It may be annotated, that degradation rates and formation fractions of spirotetramat-ketohydroxy and 

spirotetramat-MA-amide obtained from the more simplistic SFO  SFO  SFO, FOMC  SFO  SFO or 

DFOP  SFO  SFO kinetics approaches (lower tier approaches) are almost identical to the data obtained 

from the higher tier approach SFO-RB  SFO  SFO. This is reasonable since the release of spirotetramatketohydroxy from spirotetramat-enol is almost exclusively attributed to the initial and fast degradation phase 

of the (mobile) spirotetramat-enol fraction. The formation of spirotetramat-ketohydroxy from the second and 

slower phase of the strongly bound (immobile) spirotetramat-enol fraction is considerably almost negligible. 

In this respect, a reasonable groundwater risk assessment may be solely based on obtained SFO 

degradation rates for all, the parent and all metabolites including spirotetramat-enol. The strongly bound 

spirotetramat-enol fraction in the soil is considered immobile (no potential for leaching) and does not 

significantly attribute to the further formation of metabolites owing to its rather slow degradation. 

In a separate degradation study, the soil photolysis metabolite 4-methoxy-cyclohexanone was shown to 

degrade very quickly in all three tested soils under aerobic conditions. The half-live was < 1 day.
– 77 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.2.6-1: Summary on laboratory non-normalized, recalculated and normalized recalculated DegT50 and DegT90 values [days] of spirotetramat 

and spirotetramat-enol (both used as parent in the respective studies) in soil according to DFOP (best fit for both compounds), FOMC and SFO kinetics. 

DFOP (best fit kinetics) FOMC SFO 

Compound Soil DegT50

[days] 

DegT90

[days] 

DegT50 

recalc

a

[days] 

Norm. 

DegT50 

recalc

[days] 

DegT50

[days] 

DegT90

[days] 

DegT50 

recalc

a

[days] 

Norm. 

DegT50 

recalc

[days] 

DegT50

[days] 

DegT90

[days] 

Norm. 

DegT50

[days] 

‘Laacherhof AXXa’ 0.24 0.89 0.27 0.21 0.23 1.04 0.31 0.24 0.21 0.69 0.17 ‘Laacherhof AIII’ 0.26 0.97 0.29 0.21 0.25 1.09 0.33 0.23 0.23 0.77 0.16 ‘Hoefchen’ 0.09 0.34 0.10 0.07 0.01 0.44 0.13 0.09 0.08 0.28 0.05 ‘Molino’ 0.30 1.26 0.38 0.26 0.26 2.61 0.79 0.55 0.33 1.09 0.23 Geometric mean (EU) nc nc 0.23 0.17 nc nc 0.32 0.23 0.19 0.63 0.13 80th %ile (PMRA) nc nc 0.33 nc nc nc 0.51 nc 0.27 0.90 nc 

Spirotetramat 

(parent in study)

90th %ile C.I. on meanb (US-EPA) nc nc 0.36 nc nc nc 0.62 nc 0.30 0.98 nc ‘Laacherhof AXXa’ 0.02 28.9 12.3 10.9 0.02 9.8 2.95 2.64 0.022 0.072 0.017 ‘Laacherhof AIII’ 0.18 40.9 5.1 4.1 0.12 5.8 1.75 1.42 0.22 0.73 0.16 ‘Hoefchen’ 0.02 16.8 3.3 2.5 0.02 2.6 0.79 0.61 0.020 0.066 0.013 ‘Molino’ 0.06 10.9 8.7 6.3 0.06 3.6 1.10 0.80 0.098 0.33 0.068 Geometric mean (EU) nc nc 6.5 5.2 nc nc 1.46 1.16 0.055 0.18 0.039 80th %ile (PMRA) nc nc 10.1 nc nc 7.4 2.23 nc 0.15 0.49 nc 

Spirotetramatenol 

(parent in study)

90th %ile C.I. on meanb (US-EPA) nc nc 10.6 nc nc 8.1 2.43 nc 0.17 0.56 nc 

a Conservative SFO-DT50 recalculated from DFOP-DT90 and FOMC-DT90, respectively, divided by 3.32. b Calculated by [arithmetic mean + (t90,n-1 × SD) / n0.5], whereby t90,n-1 = one-sided students t value at α = 0.1, SD = standard deviation and n = number of data available 
– 78 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.2.6-2: Summary on non-normalized and normalized DegT50 and DegT90 values [days] of 

spirotetramat-enol, spirotetramat-ketohydroxy and spirotetramat-MA-amide in soil obtained from the 

degradation study using spirotetramat-enol as parent (multi-compartment modelling accounting for 

SFO-RB kinetics of spirotetramat-enol). 

Compound Soil DegT50

[days] 

DegT90

[days] 

Norm. 

DegT50

[days] 

fne [-] kd 

[days-1] 

Formation 

fraction 

[0 ... 1] 

Kinetics 

‘Laacherhof AXXa’ 0.02 0.07 0.02 693 0.012 - SFO-RB 

‘Laacherhof AIII’ 0.16 0.53 0.13 28.9 0.037 - SFO-RB 

‘Hoefchen’ 0.02 0.06 0.02 594 0.012 - SFO-RB 

‘Molino’ 0.05 0.17 0.04 193 0.013 - SFO-RB 

Geometric mean (EU) 0.04 0.14 0.03 377a0.016 - 

80th %ile (PMRA) 0.09 0.31 nc - - - 

Spirotetramatenol 

(parent in 

study)

90th %ile of C.I. on 

meanb(US-EPA)

0.12 0.39 nc - - - 

‘Laacherhof AXXa’ 4.2 13.9 3.8 - - 0.223 SFO 

‘Laacherhof AIII’ 5.1 16.9 4.1 - - 0.356 SFO 

‘Hoefchen’ 1.5 5.1 1.2 - - 0.243 SFO 

‘Molino’ 16.7 55.6 12.1 - - 0.206 SFO 

Geometric mean (EU) 4.8 16.1 3.9 - - 0.257 

80th %ile (PMRA) 9.7 32.3 nc - - - 

Spirotetramatketohydroxy 

90th %ile of C.I. on 

meanb(US-EPA)

12.4 41.2 nc - - - 

‘Laacherhof AXXa’ 1.1 3.6 1.0 - - 1.00c SFO 

‘Laacherhof AIII’ 1.8 6.3 1.5 - - 1.00c SFO 

‘Hoefchen’ 0.3 1.0 0.2 - - 1.00c SFO 

‘Molino’ 5.4 18.1 3.9 - - 1.00c SFO 

Geometric mean (EU) 1.3 4.5 1.0 - - 1.00 

80th %ile (PMRA) 3.2 11.0 nc - - - 

SpirotetramatMA-amide 

90th %ile of C.I. on 

meanb(US-EPA)

4.0 13.4 nc - - - 

a

 Arithmetic mean 

b

 Calculated by [arithmetic mean + (t90,n-1 × SD) / n0.5], whereby t90,n-1 = one-sided students t value at α = 0.1, SD = standard deviation 

and n = number of data available 

c

 Fixed to maximum (i.e. 1.00) during fitting procedure 
– 79 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

B.8.1.3 Field studies (OECD Annex IIA, 7.3, IIIA, 9.2) 

B.8.1.3.1 Soil dissipation testing (OECD Annex IIA, 7.3.1, IIIA, 9.2.1) 

Field dissipation of spirotetramat and metabolites was investigated in four US field trials: 

• New York, US 

• Florida, US 

• California, US 

• Washington, US 

Reference: Terrestrial field dissipation of BYI08330 in New York Soil, 2004 

Author(s), year: Lenz, M., 2006a 

Study/Report number: M-277191-01-1, MEFNY004 

Guideline(s): US-EPA No. 164-1: Terrestrial field dissipation, PMRA Data Code No. 8.3.2.1 

GLP: Yes 

Deviations: None 

Validity: Study considered acceptable 

Material and methods:

Test substance: Spirotetramat (unlabelled) as oil dispersion formulation BYI08330 100 OD containing 

102.02 g ai L-1, batch 08030/0110(0073) 

Internal standard: 13C-spirotetramat, 13C-spirotetramat-enol, 13C-spirotetramat-ketohydroxy and 13Cspirotetramat-MA-amide 

Plot preparation and 

maintenance: 

Bare ground plot (77.7 × 4.6 m, 360 m2

) divided into three subplots (25.9 × 4.6 m, 

120 m2

), one control plot (7.3 × 4.6 m, 34 m2), plots maintained fallow with nonselective herbicides (glyphosate, paraquat) 

Application: 439 g ai ha-1 as a liquid spray, 220 L ha-1, liquid broadcast spray (boom sprayer) 

Application date: 14th June, 2004 

Study duration: 542 days 

Irrigation: 14 irrigation events, seasonally applied as needed, 13 – 14 mm each time 

Application 

verification: 

• Whatman filter pads (24 cm diameter, 452 cm2), two per subplot, immediately 

sampled after application 

• soil pans (approx. 24 x 33 cm, 797 cm2

) with 450 g of soil, one per subplot, 

immediately sampled after application 

Sampling: 5 cores (5.7 cm diameter) from each subplot per sampling data, composited into one 

sample per soil depth, 122 cm sampling depth, 15 cm soil core length, soil cores 

were analysed until two residue free layers were found 

Sample processing: • filter pads: extracted with 5 ml formic acid and 495 ml of 4 g L-1 cysteine 

hydrochloride in 2.5 % ethyl acetate in water/acetonitrile (50/50, v/v) solution, 

aliquot fortified with internal 13C standard solution, filtered and measured by 

LC/MS/MS 

• Soil pans: same method used for the soil samples 

• Soil samples: microwave extraction (twice) of 20 g soil with 50 ml of 

acetonitrile/water (50/50, v/v) containing 8 g L-1 cysteine hydrochloride and 5 

% ethyl acetate at 70 °C for 30 min, aliquot fortified with internal 13C standard 

solution, filtered and measured by LC/MS/MS (analytical method FN-002-

S05-03) 

Sample storage 

length: 

Soil samples stored frozen for maximum 786 days (analysis period: 20th October 

2005 – 9th June 2006) 
– 80 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Monitoring: Daily weather conditions, soil moisture at 5 and 30 cm soil depth 

Analytical 

techniques: 

LC/MS/MS 

LOQ = 5 μg kg-1 (each analyte) 

LOD = 0.5 μg kg-1 (spirotetramat, spirotetramat-enol), 0.9 μg kg-1 (spirotetramatketohydroxy), 2.1 μg kg-1 (spirotetramat-MA-amide) 

Fortification solution: Mixture of spirotetramat, spirotetramat-enol, spirotetramatketohydroxy and spirotetramat-MA-amide (fortification at 5.0 μg kg-1 each) 

Kinetic evaluation: • Parent and total combined residues: simple first order (SFO) kinetics: 

• Spirotetramat-enol and spirotetramat-ketohydroxy: 

SpirotetramatSFO  (spirotetramat-enol + spirotetramat-ketohydroxy)SFO 

sink (no additional pathways to sink) (additional evaluation by the reviewer): 

All data without normalization, MATLAB 7.0.4 

Table B.8.1.3.1-1: Study site. 

Location New York, USA 

Slope gradient: 0 % 

Depth to groundwater: > 1.8 m 

30 years average rainfall: 974 mm 

30 years mean temperature: 9.1 °C 

Weather conditions during study: Within 30 years normal level, total water input 122 % of average rainfall 

Study mean temperature: 8.1 °C (June 2004 – May 2005), 13.9 °C (June 2005 – December 2005) 

Study rainfall: 941 mm (June 2004 – May 2005), 728 mm (June 2005 – December 2005) 

Study irrigation: 80 mm (June 2004 – May 2005), 106 mm (June 2005 – December 2005) 

Total precipitation (rainfall + irrigation): 1021 mm (June 2004 – May 2005), 834 mm (June 2005 – December 2005) 

Crops grown: 2001: alfalfa, 2002: alfalfa, 2003: alfalfa 

Pesticides used: 2001: Fusilade, Balan, Buctril, Pursuit, Baythroid, Post Plus, Kerb, Sencor, 

2002: Baythroid, Buctril, Post Plus, 2003: Velpar, Baythroid, Kerb 

Fertilizer: Not available 

Plot preparation: Tillage 

Parent 

Spirotetramat-enol + 

Spirotetramat-ketohydroxy Sink 

Parent Sink 

Combined residues Sink 
– 81 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.3.1-2: Soil properties. 

Soil depth [cm] Property 

0 – 15 15 – 30 30 – 45 45 – 60 60 – 75 75 – 90 90 – 105 105 – 122 

Texture (USDA) Loamy 

sand 

Loamy 

sand 

Loamy 

sand Sand Sand Sand Sand Sand 

Sand (USDA) [%] 85 85 85 89 89 91 91 91 

Silt (USDA) [%] 6 7 9 6 6 5 7 7 

Clay (USDA) [%] 9 8 6 5 5 4 2 2 

pH (soil/water, 1/1, m/v) 6.3 6.3 5.8 5.3 5.1 5.2 5.4 5.5 

pH (0.01 M CaCl2) 5.5 5.5 5.0 4.6 4.5 4.5 4.6 4.6 

Organic carbon [%]a 0.75 0.70 0.29 0.23 0.17 0.06 0.06 0.12 

CEC [meq kg-1] 45 45 43 38 34 29 27 30 

Bulk density [g cm-3] 1.40 1.38 1.41 1.43 1.44 1.47 1.49 1.46 

MC (1/3 bar) [%] 8.9 8.2 6.3 5.6 6.0 4.3 4.1 4.4 

a

 Organic carbon = organic matter / 1.724 

Findings:

Daily soil moisture monitored at a soil depth of 30 cm was above field capacity (at 1/3 bar) throughout the 

study duration. Soil moisture at 5 cm was pushed beyond field capacity by frequent rainfall and irrigation. 

Therefore, sufficient water was applied to the test plot to promote leaching of the test substance. 

Mean recovery of fortified control soil samples (5.0 μg kg-1 of each analyte) were 107, 112, 96 and 112 % for 

spirotetramat, spirotetramat-enol, spirotetramat-ketohydroxy and spirotetramat-MA-amide, respectively.

Application verification filter paper and soil pans showed an average parent equivalent recovery of 94 % and 

96 % of the application rate, respectively. Average 0 DAT concentration of spirotetramat was 74.1 μg kg

-1

. 

Spirotetramat and its transformation products were not found below 15 cm of soil depth. Spirotetramat 

degraded to < LOD (0.5 μg kg-1) by 14 DAT, major degradation products formed were spirotetramat-enol 

(maximum 46.0 μg ai kg-1 by 1 DAT declining to 4.2 μg ai kg-1 by study termination) and spirotetramatketohydroxy (26.0 μg kg-1 by 1 DAT declining to < LOD by study termination).
– 82 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.3.1-3: Total average residues [μg kg-1] in soil samples (0 – 45 cm layer) collected from Now York bare ground plot. 

Spirotetramat Spirotetramat-enol Spirotetramat-ketohydroxy Spirotetramat-MA-amide 

DAT 0 – 15 

cm 

15 – 30 

cm 

30 – 45 

cma

Total 

(0 – 45 

cm) 

0 – 15 

cm 

15 – 30 

cm 

30 – 45 

cma

Total 

(0 – 45 

cm) 

0 – 15 

cm 

15 – 30 

cm 

30 – 45 

cma

Total 

(0 – 45 

cm) 

0 – 15 

cm 

15 – 30 

cm 

30 – 45 

cma

Total 

(0 – 45 

cm) 

-4 < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD 

0 74.1 na na 74.1 8.7 na na 8.7 12.2 na na 12.2 < LOD na na < LOD 1 17.7 < LOD < LOD 17.7 46.0 < LOD < LOD 46.0 26.0 < LOD < LOD 26.0 < LOD < LOD < LOD < LOD 3 2.2a < LOD < LOD 2.2a 40.3 < LOD < LOD 40.3 24.5 < LOD < LOD 24.5 2.7a < LOD < LOD 2.7a7 1.3a < LOD < LOD 1.3a 32.2 < LOD < LOD 32.2 22.6 < LOD < LOD 22.6 < LOD < LOD < LOD < LOD 

14 < LOD < LOD < LOD < LOD 39.5 < LOD < LOD 39.5 16.9 < LOD < LOD 16.9 < LOD < LOD < LOD < LOD 28 < LOD < LOD < LOD < LOD 16.8 < LOD < LOD 16.8 12.0 < LOD < LOD 12.0 < LOD < LOD < LOD < LOD 60 < LOD < LOD < LOD < LOD 14.3 < LOD < LOD 14.3 3.0a < LOD < LOD 3.0a < LOD < LOD < LOD < LOD 

121 < LOD < LOD < LOD < LOD 8.3 < LOD < LOD 8.3 1.5a < LOD < LOD 1.5a < LOD < LOD < LOD < LOD 179 < LOD < LOD < LOD < LOD 8.8 < LOD < LOD 8.8 1.3a < LOD < LOD 1.3a < LOD < LOD < LOD < LOD 289 < LOD < LOD < LOD < LOD 11.6 < LOD < LOD 11.6 1.8a < LOD < LOD 1.8a < LOD < LOD < LOD < LOD 365 < LOD < LOD < LOD < LOD 4.8a < LOD < LOD 4.8a 1.2a < LOD < LOD 1.2a < LOD < LOD < LOD < LOD 542 < LOD < LOD < LOD < LOD 4.2a < LOD < LOD 4.2a < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD 

a Residues < LOQ (5 μg kg-1) 

LOD = limit of detection (0.5 μg kg-1 for spirotetramat and spirotetramat-enol, 0.9 μg kg-1 for spirotetramat-ketohydroxy, 2.1 μg kg-1 for spirotetramat-MA-amide) 

na = not analysed 
– 83 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.3.1-4: Average residues [μg kg-1] of spirotetramat and average parent equivalents [μg ai 

equiv kg-1] of spirotetramat-enol, spirotetramat-ketohydroxy and spirotetramat-MA-amide in soil 

samples from 0 – 45 cm colleted from New York bare ground plots. 

Bare ground plot 

DAT

Spirotetramat Spirotetramat-enol Spirotetramatketohydroxy 

Spirotetramat-MAamide Total 

-4 < LOD < LOD < LOD < LOD < LOD 

0 74.1 10.8 14.4 < LOD 99.3 

1 17.7 57.0 30.6 < LOD 105.3 

3 2.2 49.9 28.8 2.7 83.6 

7 1.3 39.9 26.6 < LOD 67.8 

14 < LOD 48.9 19.9 < LOD 68.8 

28 < LOD 20.8 14.1 < LOD 34.9 

60 < LOD 17.7 3.5 < LOD 21.2 

121 < LOD 10.3 1.8 < LOD 12.1 

179 < LOD 10.9 1.5 < LOD 12.4 

289 < LOD 14.4 2.1 < LOD 16.5 

365 < LOD 5.9 1.4 < LOD 7.3 

542 < LOD 5.2 < LOD < LOD 5.2 

Table B.8.1.3.1-5: Calculated dissipation half-life [days] of spirotetramat, spirotetramat-enol, 

spirotetramat-ketohydroxy and total combined residues in New York bare ground soil (nonnormalized) based on SFO kinetics. 

Study site Substance DT50

[days] 

DT90

[days] R

2

χ

2

error 

[%] 

Formation 

fraction 

[0 ... 1] 

Kinetics 

Spirotetramat 0.5 1.6 0.94 5.1 - SFO 

Sum of spirotetramat-enol + 

spirotetramat ketohydroxyb 31.6 105 nc 16.6 1.0a

 All SFO in series New York 

bare ground 

Total combined residuesc 23.4 77.8 0.93 16.4 - SFO 

a

 No additional pathways to sink assumed, therefore fixed to 1.0 during modelling

b

 Calculated by the reviewer (see comments) 

c

 Total combined residues: sum of spirotetramat, spirotetramat-enol, spirotetramat-ketohydroxy, spirotetramat-MA-amide 

Conclusion:

Spirotetramat dissipated rapidly under field conditions on bare ground plots with a DT50 of 0.49 days and a 

DT90 of 1.62 days (R2

 = 0.94, SFO kinetics, χ

2

 error = 5.1 %). Residues of spirotetramat and its 

transformation products were not found > LOD below the 0 – 15 cm soil layer. Total combined residues 

dissipated with a DT50 of 23.4 days. Combined residues of spirotetramat-enol and spirotetramat-ketohydroxy 

degraded with a DT50 of 31.6 days. 

Reviewer comments:

• Owing to the distinct storage instability of spirotetramat-enol (degrading to spirotetramat-ketohydroxy 

and bound to the soil matrix during freeze storage, see Netzband, 2006), residues of spirotetramatenol and spirotetramat-ketohydroxy should not be evaluated individually. 

• Samples were screened for spirotetramat-enol dimer 1 and spirotetramat-enol dimer 2 (position 

paper Hellpointner et al., 2007). Both dimers stayed below a concentration of 0.2 % of applied 

during the whole course of the trial. In this respect, dimerization of spirotetramat-enol, frequently 

observed in laboratory studies after hot-spot application, has to be considered negligible under 

environmental conditions. 
– 84 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Reference: Terrestrial field dissipation of BYI08330 in Florida Soil, 2004 

Author(s), year: Lenz, M., 2006b 

Study/Report number: M-277184-01-1, MEFNX055 

Guideline(s): US-EPA No. 164-1: Terrestrial field dissipation, PMRA Data Code No. 8.3.2.1 

GLP: Yes 

Deviations: None 

Validity: Study considered acceptable 

Material and methods:

Test substance: Spirotetramat (unlabelled) as oil dispersion formulation BYI08330 100 OD containing 

102.02 g ai L-1, batch 08030/0110(0073) 

Internal standard: 13C-spirotetramat, 13C-spirotetramat-enol, 13C-spirotetramat-ketohydroxy and 13Cspirotetramat-MA-amide 

Plot preparation and 

maintenance: 

Two treatments (test plots): 

• Bare ground 

• Cropped (bush beans ‘Blue Lake’, planted 23rd April, 2004) 

Both plots (each 3.0 × 36.6 m, 110 m2

) divided into three subunits (3.0 × 12.2 m, 37 

m

2

), one control plot (3.0 × 12.2 m, 37 m2), bare ground plot maintained fallow with a 

non-selective herbicide (glyphosate) 

Application: 439 g ai ha-1 as a liquid spray, 250 L ha-1, liquid broadcast spray (CO2 backpack 

sprayer) 

Application date: 27th April, 2004 

Study duration: 540 days 

Irrigation: 28 irrigation events, seasonally applied as needed, 8 – 46 mm each time 

Application 

verification: 

• Whatman filter pads (24 cm diameter, 452 cm2), 2 pads per subunit, 

immediately sampled after application 

• soil pans (248 cm2) with 85 g of soil, 1 pan per subunit, immediately sampled 

after application 

Sampling: 5 cores (5.7 cm diameter) from each subplot per sampling data, composited into one 

sample per soil depth, 122 cm sampling depth, 15 cm soil core length, soil cores 

were analysed until two residue free layers were found 

Sample processing: • filter pads: extracted with 5 ml formic acid and 495 ml of 4 g L-1 cysteine 

hydrochloride in 2.5 % ethyl acetate in water/acetonitrile (50/50, v/v) solution, 

aliquot fortified with internal 13C standard solution, filtered and measured by 

LC/MS/MS 

• Soil pans: same method used for the soil samples 

• Soil samples: microwave extraction (twice) of 20 g soil with 50 ml of 

acetonitrile/water (50/50, v/v) containing 8 g L-1 cysteine hydrochloride and 5 

% ethyl acetate at 70 °C for 30 min, aliquot fortified with internal 13C standard 

solution, filtered and measured by LC/MS/MS (analytical method FN-002-

S05-03) 

Sample storage 

length: 

Soil samples stored frozen for maximum 786 days (Analysis period: 21st October 

2005 – 19th June 2006) 

Monitoring: Daily weather conditions, soil moisture at 5 and 30 cm soil depth 

Analytical 

techniques: 

LC/MS/MS 

LOQ = 5 μg kg-1 (each analyte) 

LOD = 0.5 μg kg-1 (spirotetramat, spirotetramat-enol), 0.9 μg kg-1 (spirotetramatketohydroxy), 2.1 μg kg-1 (spirotetramat-MA-amide) 

Fortification solution: Mixture of spirotetramat, spirotetramat-enol, spirotetramatketohydroxy and spirotetramat-MA-amide (fortification at 5.0 μg kg-1 each) 
– 85 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Kinetic evaluation: • Parent and total combined residues: simple first order (SFO) kinetics: 

• Spirotetramat-enol and spirotetramat-ketohydroxy: 

SpirotetramatSFO  (spirotetramat-enol + spirotetramat-ketohydroxy)SFO 

sink (no additional pathways to sink) (additional evaluation by the reviewer): 

All data without normalization, MATLAB 7.0.4 

Table B.8.1.3.1-6: Study site. 

Location Seminole County, Florida, USA 

Slope gradient: ≤ 1 % 

Depth to groundwater [m]: > 0.9 

30 years average rainfall: 1228 mm 

30 years mean temperature: 22.7 °C 

Weather conditions during study: Within 29 years normal level, total water input 134 % of average rainfall 

Study rainfall: 1544 mm (April 2004 – March 2005), 974 mm (April 2005 – October 2005) 

Study irrigation: 218 mm (April 2004 – March 2005), 106 mm (April 2005 – October 2005) 

Total precipitation (rainfall + irrigation): 1763 mm (April 2004 – March 2005), 1201 mm (April 2005 – October 2005) 

Crops grown: 2000: fallow, 2001: fallow, 2002: fallow, 2003: sweetcorn, 2004: fallow 

Pesticides used: 2003: Warrior, Lambda-cyhalothrin 

Fertilizer used: 2003: 10-10-10, 34-0-0 

Plot preparation: Tillage 

Table B.8.1.3.1-7: Soil properties (updated numbers according to the position paper Hellpointner et 

al., 2007). 

Soil depth [cm] Property 

0 – 15 15 – 30 30 – 45 45 – 60 60 – 75 75 – 90 90 – 105 105 – 122 

Texture (USDA) Sand Sand Sand Sand Sand Sand Sand Sand 

Sand (USDA) [%] 95 96 96 95 94 92 94 92 

Silt (USDA) [%] 3 2 2 3 3 4 3 4 

Clay (USDA) [%] 2 2 2 3 3 4 3 4 

pH (soil/water, 1/1, m/v) 7.1 7.0 6.9 6.9 6.9 6.8 6.9 6.8 

pH (0.01 M CaCl2) na na na na na na na na 

Organic carbon [%]a 0.2 0.1 0.1 0.2 0.3 0.5 0.3 0.5 

CEC [meq kg-1] 15 10 9 14 26 42 26 42 

Bulk density [g cm-3] 1.4 1.4 1.4 1.4 1.4 1.3 1.4 1.3 

MC (1/3 bar) [%] 1.6 1.5 1.4 1.7 2.8 3.9 2.8 3.9 

MC (15 bar) [%] 1.3 1.2 1.0 1.1 1.4 1.9 1.4 1.0 

a

 Organic carbon = organic matter / 1.724 

Findings:

Daily soil moisture monitored at a soil depth of 5 and 30 cm was above field capacity (at 1/3 bar) throughout 

the study duration. Therefore, sufficient water was applied to the test plot to promote leaching of the test 

substance. 

Parent Sink 

Combined residues Sink 

Parent 

Spirotetramat-enol + 

Spirotetramat-ketohydroxy Sink 
– 86 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Mean recovery of fortified control soil samples (5.0 and 50.0 μg kg-1 of each analyte) were 103, 103, 91 and 

94 % for spirotetramat, spirotetramat-enol, spirotetramat-ketohydroxy and spirotetramat-MA-amide, 

respectively. 

Bare soil plot: 

Application verification filter paper and soil pans showed an average parent equivalent recovery of 85 % and 

95 % of the application rate, respectively. Average 0 DAT concentration of spirotetramat in the 0 – 15 cm soil 

segment was 37.9 μg kg-1. Residues of spirotetramat were less than LOD (0.5 μg kg-1) by 14 DAT. 

Spirotetramat was not found below 15 cm of soil depth with the exception of the 1 DAT sampling, where 

residues of spirotetramat were almost equally distributed within 0 – 30 cm of soil depths (residues in the 30 – 

45 cm layer < LOQ). Major transformation products were spirotetramat-enol and spirotetramat-ketohydroxy. 

Maximum of total concentration of spirotetramat-enol was 30.3 μg kg-1 by 1 DAT declining to non detectable 

amounts by 185 DAT. The total concentration of spirotetramat-ketohydroxy reached a maximum of 46.3 μg 

kg-1 by 1 DAT, residues completely dissipated to below the LOD by 126 DAT. Residues of metabolites were 

not detectable > LOD below 30 cm of soil depth with the exception of the 1 DAT sampling (amounts < LOQ). 

Cropped plot: 

Application verification filter paper and soil pans showed an average parent equivalent recovery of 82 % and 

98 % of the application rate, respectively. Average 0 DAT concentration of spirotetramat in the 0 – 15 cm soil 

segment was 59.1 μg kg-1. Residues of spirotetramat were less than LOD (0.5 μg kg-1) by 14 DAT. 

Spirotetramat was not found below 15 cm of soil depth with the exception of the 1 DAT sampling, where 

residues of spirotetramat were almost equally distributed within 0 – 30 cm of soil depths (residues in the 30 – 

45 cm layer < LOQ). Major transformation products were spirotetramat-enol and spirotetramat-ketohydroxy. 

Maximum of total concentration of spirotetramat-enol was 36.5 μg kg-1 by 1 DAT declining to non detectable 

amounts at the end of the study. The total concentration of spirotetramat-ketohydroxy reached a maximum of 

47.6 μg kg-1 by 1 DAT, residues completely dissipated to below the LOD by 185 DAT. Residues of 

metabolites were not detectable > LOQ (i.e. 5 μg kg-1) below 30 cm of soil depth (few finding close to the 

LOD, especially in 1 DAT samples). 
– 87 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.3.1-8: Average residues [μg kg-1] in soil samples (0 – 45 cm layer) collected from Florida bare ground plot. 

Spirotetramat Spirotetramat-enol Spirotetramat-ketohydroxy Spirotetramat-MA-amide 

DAT 0 – 15 

cm 

15 – 30 

cm 

30 – 45 

cm 

Total 

(0 – 45 

cm) 

0 – 15 

cm 

15 – 30 

cm 

30 – 45 

cm 

Total 

(0 – 45 

cm) 

0 – 15 

cm 

15 – 30 

cm 

30 – 45 

cm 

Total 

(0 – 45 

cm) 

0 – 15 

cm 

15 – 30 

cm 

30 – 45 

cm 

Total 

(0 – 45 

cm) 

-1 < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD 

0 37.9 na na 37.9 28.5 na na 28.5 32.6 na na 32.8 < LOD na na < LOD 1 23.5 25.5 2.7a 51.7 20.8 7.7 1.8a 30.3 32.8 12.1 1.4a 46.3 < LOD < LOD < LOD < LOD 3 9.1 < LOD < LOD 9.1 15.4 < LOD < LOD 15.4 38.3 < LOD < LOD 38.3 < LOD < LOD < LOD < LOD 7 1.3a < LOD < LOD 1.3 16.6 3.2a < LOD 19.8 19.7 7.2 < LOD 26.9 < LOD < LOD < LOD < LOD 

14 < LOD < LOD < LOD < LOD 12.5 2.0a < LOD 14.5 15.0 2.7a < LOD 17.7 < LOD < LOD < LOD < LOD 28 < LOD < LOD < LOD < LOD 5.2 < LOD < LOD 5.2 4.1a 3.8a < LOD 7.9 < LOD < LOD < LOD < LOD 59 < LOD < LOD < LOD < LOD 5.1 0.8a < LOD 5.9 2.3a 1.4a < LOD 3.7a < LOD < LOD < LOD < LOD 

126 < LOD < LOD < LOD < LOD 3.2 < LOD < LOD 3.2a < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD 185 < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD 266 na na na na na na na na na na na na na na na na 367 na na na na na na na na na na na na na na na na 540 na na na na na na na na na na na na na na na na 

a Residues < LOQ (5 μg kg-1) 

LOD = limit of detection (0.5 μg kg-1 for spirotetramat and spirotetramat-enol, 0.9 μg kg-1 for spirotetramat-ketohydroxy, 2.1 μg kg-1 for spirotetramat-MA-amide) 

na = not analysed 
– 88 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.3.1-9: Total average residues [μg kg-1] in soil samples (0 – 45 cm layer) collected from Florida cropped plot. 

Spirotetramat Spirotetramat-enol Spirotetramat-ketohydroxy Spirotetramat-MA-amide 

DAT 0 – 15 

cm 

15 – 30 

cm 

30 – 45 

cm 

Total 

(0 – 45 

cm) 

0 – 15 

cm 

15 – 30 

cm 

30 – 45 

cm 

Total 

(0 – 45 

cm) 

0 – 15 

cm 

15 – 30 

cm 

30 – 45 

cm 

Total 

(0 – 45 

cm) 

0 – 15 

cm 

15 – 30 

cm 

30 – 45 

cm 

Total 

(0 – 45 

cm) 

-1 < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD 

0 59.1 na na 59.1 33.3 na na 33.3 41.8 na na 41.8 < LOD na na < LOD 1 35.2 35.5 2.7a 70.7 22.6 12.9 1.0ab 36.5 30.5 17.1 < LOD 47.6 < LOD < LOD < LOD < LOD 3 18.2 < LOD < LOD 18.2 16.1 < LOD < LOD 16.1 46.4 < LOD < LOD 46.4 < LOD < LOD < LOD < LOD 7 0.8a < LOD < LOD 0.8 8.6 8.9 0.8a 17.5 19.3 17.7 < LOD 37.0 < LOD < LOD < LOD < LOD 

14 < LOD < LOD < LOD < LOD 7.1 2.3a < LOD 9.4 13.3 4.5a < LOD 17.8 < LOD < LOD < LOD < LOD 28 < LOD < LOD < LOD < LOD 6.7 < LOD < LOD 6.7 5.5 2.3a < LOD 7.8 < LOD < LOD < LOD < LOD 59 < LOD < LOD < LOD < LOD 3.5a 1.1a < LOD 4.6a 1.8a 1.7a < LOD 3.5a < LOD < LOD < LOD < LOD 

126 < LOD < LOD < LOD < LOD 3.1a 1.2a < LOD 4.3a 0.7a 0.7a < LOD 1.4a < LOD < LOD < LOD < LOD 185 < LOD < LOD < LOD < LOD 1.9a 1.0a < LOD 2.9a < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD 266 na na na na na na na na na na na na na na na na 367 na na na na na na na na na na na na na na na na 540 na na na na na na na na na na na na na na na na 

a Residues < LOQ (5 μg kg-1) b In the original study determined as < LOD (n.d.). However, according to the individual replicates presented in an additional table, this value should be 1.0 (mean of 3 replicates) 

LOD = limit of detection (0.5 μg kg-1 for spirotetramat and spirotetramat-enol, 0.9 μg kg-1 for spirotetramat-ketohydroxy, 2.1 μg kg-1 for spirotetramat-MA-amide) 

na = not analysed 
– 89 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.3.1-10: Average residues [μg kg-1] of spirotetramat and parent equivalents [μg ai equiv kg1

] of spirotetramat-enol, spirotetramat-ketohydroxy and spirotetramat-MA-amide in soil samples from 

0 – 45 cm colleted from Florida bare ground and cropped plots. 

Bare ground plot Cropped plot 

DAT Spirotetramat 

Spirotetramat

-enol 

Spirotetramatketohydroxy SpirotetramatMAamide 

Total Spirotetramat 

Spirotetramatenol 

Spirotetramatketohydroxy SpirotetramatMAamide 

Total 

-1 < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD 

0 37.9 35.5 38.4 < LOD 111.8 59.1 41.3 49.2 < LOD 149.6 

1 51.7 35.3 54.5 < LOD 141.5 70.7 45.2 56.0 < LOD 171.9 

3 9.1 19.1 45.1 < LOD 73.3 18.2 19.9 54.6 < LOD 92.7 

7 1.3 24.5 31.7 < LOD 57.5 0.8 21.7 43.5 < LOD 66.0 

14 < LOD 18.0 20.8 < LOD 38.8 < LOD 11.6 20.9 < LOD 32.5 

28 < LOD 6.4 9.3 < LOD 15.7 < LOD 8.3 9.2 < LOD 17.5 

59 < LOD 7.3 4.4 < LOD 11.7 < LOD 5.7 4.1 < LOD 9.8 

126 < LOD 4.3 < LOD < LOD 4.3 < LOD 5.3 1.6 < LOD 6.9 

185 < LOD < LOD < LOD < LOD < LOD < LOD 3.6 < LOD < LOD 3.6 

266 na na na na na na na na na na 

367 na na na na na na na na na na 

540 na na na na na na na na na na 

Table B.8.1.3.1-11: Calculated dissipation half-life [days] of spirotetramat, spirotetramat-enol, and 

spirotetramat-ketohydroxy and of total combined residues in Florida bare ground and cropped soil 

plots (non-normalized) based on SFO kinetics. 

Study site Substance DT50

[days] 

DT90

[days] R

2

χ

2

error 

[%] 

Formation 

fraction 

[0 ... 1] 

Kinetics 

Spirotetramat 0.9 2.9 0.96 2.2 - SFO 

Sum of spirotetramat-enol + 

spirotetramat-ketohydroxyb 6.6 21.9 nc 26.9 1a

 All SFO in series 

Florida, 

bare ground 

plot 

Total combined residuesb 7.6 25.2 0.86 22.3 - SFO 

Spirotetramat 1.0 3.3 0.96 0.4 - SFO 

Sum of spirotetramat-enol + 

spirotetramat-ketohydroxyb 4.8 16.0 nc 26.9 1a

 All SFO in series Florida, 

cropped plot 

Total combined residuesc 5.7 19.0 0.90 18.7 - SFO 

a

 No additional pathways to sink assumed, therefore fixed to 1 during modelling

b

 Calculated by the reviewer (see comments) 

c

 Total combined residues: sum of spirotetramat, spirotetramat-enol, spirotetramat-ketohydroxy, spirotetramat-MA-amide 

Conclusion:

Spirotetramat dissipated rapidly under field conditions on bare ground and cropped plots with a DT50 of 0.9 

and 1.0 days, respectively (SFO kinetics, R2 = 0.96, χ

2

 error ≤ 2.2 %). Respective DT90 values were 2.9 and 

3.3 days, respectively. Total combined residues dissipated with a DT50 of 7.6 and 5.7 days in bare ground 

and cropped plots, respectively. Residues of spirotetramat and its transformation products were not found > 

LOQ below the 0 – 30 cm soil layer. Combined residues of spirotetramat-enol and spirotetramat-ketohydroxy 

degraded with a DT50 of 6.6 and 4.8 days in the bare ground and cropped plot, respectively. 

Reviewer comments:

• Owing to the distinct storage instability of spirotetramat-enol (degrading to spirotetramat-ketohydroxy 

and bound to the soil matrix during freeze storage, see Netzband, 2006), residues of spirotetramatenol and spirotetramat-ketohydroxy should not be evaluated individually. 
– 90 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Reference: Terrestrial field dissipation of BYI08330 in California Soil, 2004 

Author(s), year: Lenz, M., 2006c 

Study/Report number: M-277186-01-1, MEFNY002 

Guideline(s): US-EPA No. 164-1: Terrestrial field dissipation, PMRA Data Code No. 8.3.2.1 

GLP: Yes 

Deviations: None 

Validity: Study considered acceptable 

Material and methods:

Test substance: Spirotetramat (unlabelled) as oil dispersion formulation BYI08330 100 OD containing 

102.02 g ai L-1, batch 08030/0110(0073) 

Internal standard: 13C-spirotetramat, 13C-spirotetramat-enol, 13C-spirotetramat-ketohydroxy and 13Cspirotetramat-MA-amide 

Plot preparation and 

maintenance: 

Two treatments (test plots): 

• Bare ground 

• Cropped (tomatoes ‘Germain’s Seed’, planted 20th May, 2004) 

Both plots (each 90 × 6 m, approx. 540 m2

) divided into three subplots (30 × 6 m), 

one control plot (3 × 6 m, 18 m2), bare ground plot maintained fallow with a nonselective herbicides (glufosinate, glyphosate) 

Application: 439 g ai ha-1 as a liquid spray, 187 L ha-1, liquid broadcast spray 

Application date: 26th May, 2004 

Study duration: 540 days 

Irrigation: 84 irrigation events, seasonally applied as needed, 5 – 44 mm each time 

Application 

verification: 

• Gelman solvent saturation pads (13.7 × 22 cm, 301 cm2), 2 pads per subplot, 

immediately sampled after application 

• soil pans (20.3 x 29.8 cm, 607 cm2

) with 650 g of soil, 1 pan per subplot, 

immediately sampled after application 

Sampling: 5 cores (5.7 cm diameter) from each subplot per sampling data, composited into one 

sample per soil depth, 122 cm sampling depth, 15 cm soil core length, soil cores 

were analysed until two residue free layers were found 

Sample processing: • saturation pads: extracted with 5 ml formic acid and 495 ml of 4 g L-1

cysteine hydrochloride in 2.5 % ethyl acetate in water/acetonitrile (50/50, v/v) 

solution, aliquot fortified with internal 13C standard solution, filtered and 

measured by LC/MS/MS 

• Soil pans: same method used for the soil samples 

• Soil samples: microwave extraction (twice) of 20 g soil with 50 ml of 

acetonitrile/water (50/50, v/v) containing 8 g L-1 cysteine hydrochloride and 5 

% ethyl acetate at 70 °C for 30 min, aliquot fortified with internal 13C standard 

solution, filtered and measured by LC/MS/MS (analytical method FN-002-

S05-03) 

Sample storage 

length: 

Soil samples stored frozen for maximum 778 days (analysis period: 6th April 2006 – 

13th July 2006) 

Monitoring: Daily weather conditions, soil moisture at 5 and 30 cm soil depth 

Analytical 

techniques: 

LC/MS/MS 

LOQ = 5 μg kg-1 (each analyte) 

LOD = 0.5 μg kg-1 (spirotetramat, spirotetramat-enol), 0.9 μg kg-1 (spirotetramatketohydroxy), 2.1 μg kg-1 (spirotetramat-MA-amide) 

Fortification solution: Mixture of spirotetramat, spirotetramat-enol, spirotetramatketohydroxy and spirotetramat-MA-amide (fortification at 5.0 μg kg-1each) 

Kinetic evaluation: • Parent and total combined residues: simple first order (SFO) kinetics 
– 91 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

• Spirotetramat-enol and spirotetramat-ketohydroxy: 

SpirotetramatSFO  (spirotetramat-enol + spirotetramat-ketohydroxy)SFO 

sink (no additional pathways to sink) 

All data without normalization, MATLAB 7.0.4 

Table B.8.1.3.1-12: Study site. 

Location Fresno, California, USA 

Slope gradient: 0 % 

Depth to groundwater: 9.1 – 22.9 m 

30 years average rainfall: 285 mm 

30 years mean temperature: 17.3 °C 

Weather conditions during study: Within 30 years normal level, total water input 1590 % of average rainfall 

Rainfall: 363 mm (May 2004 – April 2004), 43 mm (May 2005 – November 2005) 

Irrigation: 739 mm (May 2004 – April 2004), 500 mm (May 2005 – November 2005) 

Total precipitation (rainfall + irrigation): 1102 mm (May 2004 – April 2004), 543 mm (May 2005 – November 2005) 

Crops grown: 1999: fallow, 2000: fallow, 2001: bare soil, 2002: bare soil, 2003: bare soil 

Pesticides used: 1999: Pyrimethanil, 2000: none, 2001: Roundup, 2002: Roundup, 2003: 

Roundup 

Fertilizer used: Information not available 

Plot preparation: Tillage 

Table B.8.1.3.1-13: Soil properties of the bare ground test plot. 

Soil depth [cm] Property 

0 – 15 15 – 30 30 – 45 45 – 60 60 – 75 75 – 90 90 – 105 105 – 122 

Texture (USDA) Sandy 

loam 

Sandy 

loam 

Sandy 

loam 

Sandy 

loam 

Sandy 

loam 

Sandy 

loam 

Sandy 

loam 

Sandy 

loam 

Sand (USDA) [%] 67 67 67 67 69 67 64 61 

Silt (USDA) [%] 24 24 24 24 22 24 26 28 

Clay (USDA) [%] 9 9 9 9 9 9 10 11 

pH (soil/water, 1/1, m/v) 7.2 7.2 7.2 7.3 7.6 8.5 8.5 8.7 

pH (0.01 M CaCl2) na na na na na na na na 

Organic carbon [%]a 0.29 0.23 0.17 0.17 0.12 0.12 0.12 0.12 

CEC [meq kg-1] 57 59 59 60 62 81 96 107 

Bulk density [g cm-3] 1.42 1.41 1.40 1.33 1.26 1.26 1.29 0.97 

MC (1/3 bar) [%] 8.1 8.4 8.3 8.2 8.3 11.2 14.3 26.8

a

 Organic carbon = organic matter / 1.724 

Parent 

Spirotetramat-enol + 

Spirotetramat-ketohydroxy Sink 

Parent Sink 

Combined residues Sink 
– 92 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.3.1-14: Soil properties of the cropped test plot. 

Soil depth [cm] Property 

0 – 15 15 – 30 30 – 45 45 – 60 60 – 75 75 – 90 90 – 105 105 – 122 

Texture (USDA) Sandy 

loam 

Sandy 

loam 

Sandy 

loam 

Sandy 

loam 

Sandy 

loam 

Sandy 

loam 

Sandy 

loam 

Sandy 

loam 

Sand (USDA) [%] 71 71 71 71 71 71 69 65 

Silt (USDA) [%] 22 22 22 22 22 22 27 30 

Clay (USDA) [%] 7 7 7 7 7 7 4 5 

pH (soil/water, 1/1, m/v) 6.8 6.9 6.9 7.0 7.3 7.3 7.8 8.1 

pH (0.01 M CaCl2) na na na na na na na na 

Organic carbon [%]a 0.29 0.12 0.12 0.12 0.12 0.06 0.06 0.12 

CEC [meq kg-1] 61 56 56 60 63 70 91 113 

Bulk density [g cm-3] 1.48 1.46 1.42 1.47 1.48 1.48 1.42 1.24 

MC (1/3 bar) [%] 7.6 7.7 7.2 7.0 6.9 7.4 12.3 23.1 

a

 Organic carbon = organic matter / 1.724 

Findings:

Daily soil moisture monitored at a soil depth of 5 and 30 cm were above field capacity (at 1/3 bar) throughout 

the study duration. Therefore, sufficient water was applied to the test plot to promote leaching of the test 

substance. 

Mean recovery of fortified control soil samples (5.0 μg kg-1 of each analyte) were 98, 95, 93 and 101 % for 

spirotetramat, spirotetramat-enol, spirotetramat-ketohydroxy and spirotetramat-MA-amide, respectively.

Bare soil plot: 

Application verification saturation paper and soil pans showed an average parent equivalent recovery of 97 

% and 132 % of the application rate, respectively. Average 0 DAT concentration of spirotetramat in the 0 – 

15 cm soil segment was 100.0 μg kg-1. Residues of spirotetramat were less than LOD (0.5 μg kg-1) by 14 

DAT. Spirotetramat and its transformation products were not found below 15 cm of soil depth. Major 

transformation products were spirotetramat-enol and spirotetramat-ketohydroxy. Maximum of total 

concentration of spirotetramat-enol from 0 – 45 cm soil depth was 13.6 μg kg-1 by 2 DAT declining to non 

detectable amounts at the end of the study. The total concentration of spirotetramat-ketohydroxy reached a 

maximum of 52.6 μg kg-1 by 2 DAT, residues completely dissipated to below the LOD by study termination. 

Cropped plot: 

Application verification saturation paper and soil pans showed an average parent equivalent recovery of 89 

% and 119 % of the application rate, respectively. Average 0 DAT concentration of spirotetramat in the 0 – 

15 cm soil segment was 89.4 μg kg-1. Residues of spirotetramat were less than LOD (0.5 μg kg-1) by 7 DAT. 

Spirotetramat and its transformation products were not found below 15 cm of soil depth (with the exception of 

1 DAT sampling). Major transformation products were spirotetramat-enol and spirotetramat-ketohydroxy. 

Maximum of total concentration of spirotetramat-enol from 0 – 45 cm soil depth was 9.8 μg kg-1 by 7 DAT 

declining to non detectable amounts at the end of the study. The total concentration of spirotetramatketohydroxy reached a maximum of 43.6 μg kg-1 by 2 DAT, residues completely dissipated to below the LOD 

by 120 DAT. 
– 93 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.3.1-15: Total average residues [μg kg-1] in soil samples (0 – 45 cm layer) collected from California bare ground plot. 

Spirotetramat Spirotetramat-enol Spirotetramat-ketohydroxy Spirotetramat-MA-amide 

DAT 0 – 15 

cm 

15 – 30 

cm 

30 – 45 

cm 

Total 

(0 – 45 

cm) 

0 – 15 

cm 

15 – 30 

cm 

30 – 45 

cm 

Total 

(0 – 45 

cm) 

0 – 15 

cm 

15 – 30 

cm 

30 – 45 

cm 

Total 

(0 – 45 

cm) 

0 – 15 

cm 

15 – 30 

cm 

30 – 45 

cm 

Total 

(0 – 45 

cm) 

-1 < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD 

0 100.0 na na 100.0 2.6a na na 2.6a 9.8 na na 9.8 < LOD na na < LOD 1 68.0 < LOD < LOD 68.0 7.0 < LOD < LOD 7.0 46.9 < LOD < LOD 46.9 < LOD < LOD < LOD < LOD 2 23.4 < LOD < LOD 23.4 13.6 < LOD < LOD 13.6 52.6 < LOD < LOD 52.6 2.3a < LOD < LOD 2.3a7 0.6a < LOD < LOD 0.6a 13.1 < LOD < LOD 13.1 38.9 < LOD < LOD 38.9 3.6a < LOD < LOD 3.6a

14 < LOD < LOD < LOD < LOD 9.4 < LOD < LOD 9.4 22.2 < LOD < LOD 22.2 < LOD < LOD < LOD < LOD 28 < LOD < LOD < LOD < LOD 5.1 < LOD < LOD 5.1 11.8 < LOD < LOD 11.8 2.7a < LOD < LOD 2.7a62 < LOD < LOD < LOD < LOD 2.9a < LOD < LOD 2.9a 3.7a < LOD < LOD 3.7a < LOD < LOD < LOD < LOD 

120 < LOD < LOD < LOD < LOD 0.8a < LOD < LOD 0.8a 1.2a < LOD < LOD 1.2a < LOD < LOD < LOD < LOD 187 na na na na na na na na na na na na na na na na 275 na na na na na na na na na na na na na na na na 357 na na na na na na na na na na na na na na na na 538 na na na na na na na na na na na na na na na na 

a Residues < LOQ (5 μg kg-1) 

LOD = limit of detection (0.5 μg kg-1 for spirotetramat and spirotetramat-enol, 0.9 μg kg-1 for spirotetramat-ketohydroxy, 2.1 μg kg-1 for spirotetramat-MA-amide) 

na = not analysed 
– 94 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.3.1-16: Total average residues [μg kg-1] in soil samples (0 – 45 cm layer) collected from California cropped plot. 

Spirotetramat Spirotetramat-enol Spirotetramat-ketohydroxy Spirotetramat-MA-amide 

DAT 0 – 15 

cm 

15 – 30 

cm 

30 – 45 

cm 

Total 

(0 – 45 

cm) 

0 – 15 

cm 

15 – 30 

cm 

30 – 45 

cm 

Total 

(0 – 45 

cm) 

0 – 15 

cm 

15 – 30 

cm 

30 – 45 

cm 

Total 

(0 – 45 

cm) 

0 – 15 

cm 

15 – 30 

cm 

30 – 45 

cm 

Total 

(0 – 45 

cm) 

-1 < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD 

0 89.4 na na 89.4 3.0a na na 3.0a 5.9 na na 5.9 < LOD na na < LOD 1 55.9 1.8a 0.6a 58.3 4.5a < LOD < LOD 4.5a 37.7 1.1a < LOD 38.8 < LOD < LOD < LOD < LOD 2 19.0 < LOD < LOD 19.0 6.7 < LOD < LOD 6.7 43.6 < LOD < LOD 43.6 < LOD < LOD < LOD < LOD 7 < LOD < LOD < LOD < LOD 9.8 < LOD < LOD 9.8 30.4 < LOD < LOD 30.4 4.0a < LOD < LOD 4.0a

14 < LOD < LOD < LOD < LOD 9.7 < LOD < LOD 9.7 27.9 < LOD < LOD 27.9 4.5a < LOD < LOD 4.5a28 < LOD < LOD < LOD < LOD 4.6a < LOD < LOD 4.6a 13.6 < LOD < LOD 13.6 2.7a < LOD < LOD 2.7a62 < LOD < LOD < LOD < LOD 2.3a < LOD < LOD 2.3a 2.7a < LOD < LOD 2.7a < LOD < LOD < LOD < LOD 

120 < LOD < LOD < LOD < LOD 0.9a < LOD < LOD 0.9a < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD 187 na na na na na na na na na na na na na na na na 275 na na na na na na na na na na na na na na na na 357 na na na na na na na na na na na na na na na na 538 na na na na na na na na na na na na na na na na 

a Residues < LOQ (5 μg kg-1) 

LOD = limit of detection (0.5 μg kg-1 for spirotetramat and spirotetramat-enol, 0.9 μg kg-1 for spirotetramat-ketohydroxy, 2.1 μg kg-1 for spirotetramat-MA-amide) 

na = not analysed 
– 95 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.3.1-17: Average residues [μg kg-1] of spirotetramat and parent equivalents [μg ai equiv. 

kg-1] of spirotetramat-enol, spirotetramat-ketohydroxy and spirotetramat-MA-amide in soil samples 

from 0 – 45 cm colleted from California bare ground and cropped plots. 

Bare ground plots Cropped plots 

DAT Spirotetramat 

Spirotetramatenol 

Spirotetramatketohydroxy SpirotetramatMAamide 

Total Spirotetramat 

Spirotetramatenol 

Spirotetramatketohydroxy SpirotetramatMAamide 

Total 

-1 < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD 

0 100.0 3.2 11.5 < LOD 114.7 89.4 3.7 6.9 < LOD 100.0 

1 68.0 8.7 55.2 < LOD 131.9 58.3 5.6 45.7 < LOD 109.6

2 23.4 16.9 61.9 2.6 104.8 19.0 8.3 51.3 < LOD 78.6 

7 0.6 16.2 45.8 4.0 66.6 < LOD 12.1 35.8 4.0 51.9 

14 < LOD 11.6 14.4 < LOD 26.0 < LOD 12.0 32.8 4.5 49.3 

28 < LOD 6.3 13.9 3.0 23.2 < LOD 5.7 16.0 2.7 24.4 

62 < LOD 3.6 4.4 < LOD 8.0 < LOD 2.8 3.2 < LOD 6.0 

120 < LOD 1.0 1.4 < LOD 2.4 < LOD 1.1 < LOD < LOD 1.1 

187 na na na na na na na na na na 

275 na na na na na na na na na na 

357 na na na na na na na na na na 

538 na na na na na na na na na na 

Table B.8.1.3.1-18: Calculated dissipation half-life [days] of spirotetramat, combined residues of 

spirotetramat-enol and spirotetramat-ketohydroxy, and total combined residues in California bare 

ground and cropped soil plots (non-normalized) based on SFO kinetics 

Study site Substance DT50

[days] 

DT90

[days] R

2

χ

2

error 

[%] 

Formation 

fraction 

[0 ... 1] 

Kinetics 

Spirotetramat 1.0 3.5 0.98 12.1 - SFO 

Sum of spirotetramat-enol + 

spirotetramat-ketohydroxy 7.6 25.4 0.94 14.8 1a

 All SFO in series 

California, 

bare ground 

plots 

Total combined residuesb 8.4 27.9 0.95 11.3 - SFO 

Spirotetramat 1.0 3.4 0.97 12.6 - SFO 

Sum of spirotetramat-enol + 

spirotetramat-ketohydroxy 8.7 28.9 0.90 22.4 1a

 All SFO in series California, 

cropped plots 

Total combined residuesb 10.2 33.9 0.91 13.7 - SFO 

a

 No additional pathways to sink assumed, therefore fixed to 1 during modelling

b

 Total combined residues: sum of spirotetramat, spirotetramat-enol, spirotetramat-ketohydroxy and spirotetramat-MA-amide 

Conclusion:

Spirotetramat dissipated rapidly under field conditions on bare ground and cropped plots with a DT50 of 1.0 

days in both systems (SFO kinetics, R2≥ 0.97, χ

2

 error ≤ 12.6 %). Respective DT90 values were 3.5 and 3.4 

days, respectively. Total combined residues dissipated with a DT50 of 8.4 and 10.2 days in bare ground and 

cropped plots, respectively. Residues of spirotetramat and its transformation products were not found > LOD 

below the 0 – 15 cm soil layer with the exception of the 1 DAT sampling (cropped plots only). 

Reviewer comments:

• Owing to the distinct storage instability of spirotetramat-enol (degrading to spirotetramat-ketohydroxy 

and bound to the soil matrix during freeze storage, see Netzband, 2006), residues of spirotetramatenol and spirotetramat-ketohydroxy should not be evaluated individually. 
– 96 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Reference: Terrestrial field dissipation of BYI08330 in Washington Soil, 2004 

Author(s), year: Lenz, M., 2006d 

Study/Report number: M-277189-01-1, MEFNY003 

Guideline(s): US-EPA No. 164-1: Terrestrial field dissipation, PMRA Data Code No. 8.3.2.1 

GLP: Yes 

Deviations: None 

Validity: Study considered acceptable 

Material and methods:

Test substance: Spirotetramat (unlabelled) as oil dispersion formulation BYI08330 100 OD containing 

102.02 g ai L-1, batch 08030/0110(0073) 

Internal standard: 13C3-spirotetramat, 13C3-spirotetramat-enol, 13C3-spirotetramat-ketohydroxy , 13C3-

spirotetramat-MA-amide 

Plot preparation and 

maintenance: 

Two treatments (test plots): 

• Bare ground 

• Cropped (Yellow Sweet Spanish onions, planted 1st June, 2004; Sunstar 

Spring Wheat, planted 4th May, 2005) 

Both plots (each 45.7 × 18.3 m, approx. 836 m2) divided into three subplots (15.2 × 

18.3 m), one control plot (6 × 36.6 m), 

pesticides used during study: glyphosphate, oxyfluorfen, bromoxynil, sethoxydim, 

paraquat, metribuzin, fluazifop, 2,4-D 

Application: 439 g ai ha-1 as a liquid spray, 229 L ha-1, liquid broadcast spray 

Application date: 8th June, 2004 

Study duration: 540 days 

Irrigation: 65 irrigation events, seasonally applied as needed, 3 – 12 mm each time 

Application 

verification: 

• Gelman saturation pads (13.7 × 22 cm, 301 cm2), 2 pads per subplot, 

immediately sampled after application 

• 6 soil pans (30.5 cm diameter, 779 cm2) with 650 g of soil, 1 pan per subplot, 

immediately sampled after application 

Sampling: 5 cores (5.7 cm diameter) from each subplot per sampling data, composited into one 

sample per soil depth, 122 cm sampling depth, 15 cm soil core length, soil cores 

were analysed until two residue free layers were found 

Sample processing: • filter pads: extracted with 5 ml formic acid and 495 ml of 4 g L-1 cysteine 

hydrochloride in 2.5 % ethyl acetate in water/acetonitrile (50/50, v/v) solution, 

aliquot fortified with internal 13C standard solution, filtered and measured by 

LC/MS/MS 

• Soil pans: same method used for the soil samples 

• Soil samples: microwave extraction (twice) of 20 g soil with 50 ml of 

acetonitrile/water (50/50, v/v) containing 8 g L-1 cysteine hydrochloride and 5 

% ethyl acetate at 70 °C for 30 min, aliquot fortified with internal 13C standard 

solution, filtered and measured by LC/MS/MS (analytical method FN-002-

S05-03) 

Sample storage 

length: 

Soil samples stored frozen for maximum 752 days (analysis period: 6th April 2006 – 

28th June 2006) 

Monitoring: Daily weather conditions, soil moisture at 5 and 30 cm soil depth 

Analytical 

techniques: 

LC/MS/MS 

LOQ = 5 μg kg-1 (each analyte) 

LOD = 0.5 μg kg-1 (spirotetramat, spirotetramat-enol), 0.9 μg kg-1 (spirotetramatketohydroxy), 2.1 μg kg-1 (spirotetramat-MA-amide) 

Fortification solution: Mixture of spirotetramat, spirotetramat-enol, spirotetramat-
– 97 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

ketohydroxy and spirotetramat-MA-amide (fortification at 5.0 μg kg-1each) 

Kinetic evaluation: • Parent and total combined residues: simple first order (SFO) kinetics 

• Spirotetramat-enol and spirotetramat-ketohydroxy: 

SpirotetramatSFO  (spirotetramat-enol + spirotetramat-ketohydroxy)SFO 

sink (no additional pathways to sink) 

All data without normalization, MATLAB 7.0.4 

Table B.8.1.3.1-19: Study site. 

 Bare soil plots Cropped plots 

Location Ephrata, Washington, USA 

Slope gradient: 0 - 1 % 

Depth to groundwater: 22.9 ± 3 m 

30 years average rainfall: 204 mm 

30 years mean temperature: 11.3 °C 

Weather conditions during study: Temperature within 30 years normal level, total water input 878 % of average 

rainfall 

Rainfall 159 mm (June 2004 – May 2005), 81 mm (June 2005 – Nov 2005) 

Irrigation 640 mm (June 2004 – May 2005), 549 mm (June 2005 – Nov 2005) 

Total precipitation (rainfall + irrigation) 799 mm (June 2004 – May 2005), 630 mm (June 2005 – Nov 2005) 

Crops grown: 2001: wheat, potatoes, 2002: wheat, 

2003: fallow, 2004: fallow 

2001: Potato, 2002: Potato, 2003: 

Peas, 2004: Onion 

Pesticides used: 2001: Assure II, Gramoxone Extra, 

2002: Roundup Ultra, 2003: Roundup 

Ultra, 2004: Fusilade, Gramoxone 

Extra, Goal, Touchdown, Buctril, 

Poast 

2001: Lexone DF, Poast, Diquat, 

Matrix, Temik, 2002: Roundup Ultra, 

Gramoxone Extra, Sencor, 2003: 

Treflan, 2004: Goal, Touchdown, 

Buctril, Poast, Fusilade, Gramoxone 

Extra, Sencor 

Fertilizer used: None None 

Plot preparation: Tillage, 1st June, 2004 Tillage, 1st June, 2004 

Table B.8.1.3.1-20: Soil properties of the bare ground test plot. 

Soil depth [cm] Property 

0 – 15 15 – 30 30 – 45 45 – 60 60 – 75 75 – 90 90 – 105 105 – 122 

Texture (USDA) Sandy 

loam 

Loamy 

sand 

Loamy 

sand 

Loamy 

sand Sand Sand Sand Sand 

Sand (USDA) [%] 73 79 85 85 87 89 89 94 

Silt (USDA) [%] 22 17 13 14 12 10 10 5 

Clay (USDA) [%] 5 4 2 1 1 1 1 1 

pH (soil/water, 1/1, m/v) 8.1 7.8 7.8 8.0 8.0 8.3 8.5 8.5 

pH (0.01 M CaCl2) na na na na na na na na 

Organic carbon [%]a 0.41 0.23 0.17 0.17 0.12 0.06 0.06 0.06 

CEC [meq kg-1] 120 124 127 118 116 114 122 104 

Bulk density [g cm-3] 1.39 1.48 1.58 1.62 1.66 1.65 1.65 1.68 

Parent 

Spirotetramat-enol + 

Spirotetramat-ketohydroxy Sink 

Parent Sink 

Combined residues Sink 
– 98 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Soil depth [cm] Property 

0 – 15 15 – 30 30 – 45 45 – 60 60 – 75 75 – 90 90 – 105 105 – 122 

MC (1/3 bar) [%] 12.1 10.2 8.1 7.9 6.5 6.0 5.9 4.7 

a

 Organic carbon = organic matter / 1.724 

Table B.8.1.3.1-21: Soil properties of the cropped test plot. 

Soil depth [cm] Property 

0 – 15 15 – 30 30 – 45 45 – 60 60 – 75 75 – 90 90 – 105 105 – 122 

Texture (USDA) Loamy 

sand 

Loamy 

sand 

Loamy 

sand 

Loamy 

sand Sand Sand Sand Sand 

Sand (USDA) [%] 77 77 85 85 87 88 91 93 

Silt (USDA) [%] 18 20 12 12 12 11 8 6 

Clay (USDA) [%] 5 3 3 3 1 1 1 1 

pH (soil/water, 1/1, m/v) 8.0 8.2 8.2 8.3 8.3 8.4 8.6 8.7 

pH (0.01 M CaCl2) na na na na na na na na 

Organic carbon [%]a 0.35 0.17 0.17 0.17 0.12 0.06 0.06 0.00 

CEC [meq kg-1] 121 122 135 128 113 110 105 92 

Bulk density [g cm-3] 1.52 1.57 1.57 1.56 1.65 1.68 1.70 1.69 

MC (1/3 bar) [%] 11.0 9.4 9.0 8.5 7.0 6.1 5.8 4.9 

a

 Organic carbon = organic matter / 1.724 

Findings:

Daily soil moisture monitored at a soil depth of 5 and 30 cm was above field capacity (at 1/3 bar) throughout 

the study duration. Therefore, sufficient water was applied to the test plot to promote leaching of the test 

substance. 

Mean recovery of fortified control soil samples were 98, 98, 97 and 98 % for spirotetramat, spirotetramatenol, spirotetramat-ketohydroxy and spirotetramat-MA-amide, respectively. 

Bare soil plot: 

Application verification filter paper and soil pans showed an average parent equivalent recovery of 98 % and 

80 % of the application rate, respectively. Average 0 DAT concentration of spirotetramat in the 0 – 15 cm soil 

segment was 85.4 μg kg-1. Residues of spirotetramat declined to less than LOD (0.5 μg kg-1) by 14 DAT. 

Spirotetramat and its transformation products were not found > LOD below 15 cm of soil depth. Major 

transformation products were spirotetramat-enol and spirotetramat-ketohydroxy. Maximum of total 

concentration of spirotetramat-enol was 19.3 μg kg-1 by 0 DAT declining to non detectable amounts by study 

termination. The total concentration of spirotetramat-ketohydroxy reached a maximum of 79.5 μg kg-1 by 1 

DAT, residues completely dissipated to below the LOD by study termination. 

Cropped plot: 

Application verification filter paper and soil pans showed an average parent equivalent recovery of 106 % 

and 83 % of the application rate, respectively. Average 0 DAT concentration of spirotetramat in the 0 – 15 cm 

soil segment was 69.7 μg kg-1. Residues of spirotetramat declined to less than LOD (0.5 μg kg-1) by 7 DAT. 

Spirotetramat and its transformation products were not found > LOD below 15 cm of soil depth. Major 

transformation products were spirotetramat-enol and spirotetramat-ketohydroxy. Maximum of total 

concentration of spirotetramat-enol was 24.1 μg kg-1 by 0 DAT declining to non detectable amounts at the 

end of the study. The total concentration of spirotetramat-ketohydroxy reached a maximum of 84.6 μg kg-1 by 

1 DAT, residues completely dissipated to below the LOD by 58 DAT. 
– 99 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.3.1-22: Total average residues [μg kg-1] in soil samples (0 – 45 cm layer) collected from Washington bare ground plot. 

Spirotetramat Spirotetramat-enol Spirotetramat-ketohydroxy Spirotetramat-MA-amide 

DAT 0 – 15 

cm 

15 – 30 

cm 

30 – 45 

cm 

Total 

(0 – 45 

cm) 

0 – 15 

cm 

15 – 30 

cm 

30 – 45 

cm 

Total 

(0 – 45 

cm) 

0 – 15 

cm 

15 – 30 

cm 

30 – 45 

cm 

Total 

(0 – 45 

cm) 

0 – 15 

cm 

15 – 30 

cm 

30 – 45 

cm 

Total 

(0 – 45 

cm) 

-4 < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD 

0 85.4 na na 85.4 19.3 na na 19.3 36.6 na na 36.6 < LOD na na < LOD 1 28.5 < LOD < LOD 28.5 8.2 < LOD < LOD 8.2 79.5 < LOD < LOD 79.5 < LOD < LOD < LOD < LOD 3 2.1a < LOD < LOD 2.1a 6.6 < LOD < LOD 6.6 71.8 < LOD < LOD 71.8 3.5a < LOD < LOD 3.5a7 0.5a < LOD < LOD 0.5a 4.0a < LOD < LOD 4.0a 53.4 < LOD < LOD 53.4 < LOD < LOD < LOD < LOD 

14 < LOD < LOD < LOD < LOD 2.4a < LOD < LOD 2.4a 26.6 < LOD < LOD 26.6 < LOD < LOD < LOD < LOD 28 < LOD < LOD < LOD < LOD 1.7a < LOD < LOD 1.7a 12.4 < LOD < LOD 12.4 < LOD < LOD < LOD < LOD 58 < LOD < LOD < LOD < LOD 0.7a < LOD < LOD 0.7a 5.3 < LOD < LOD 5.3 < LOD < LOD < LOD < LOD 

120 < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD 3.2a < LOD < LOD 3.2a < LOD < LOD < LOD < LOD 175 < LOD < LOD < LOD < LOD 1.2a < LOD < LOD 1.2a 2.8a < LOD < LOD 2.8a < LOD < LOD < LOD < LOD 269 na na na na na na na na na na na na na na na na 363 na na na na na na na na na na na na na na na na 538 na na na na na na na na na na na na na na na na 

a Residues < LOQ (5 μg kg-1) 

LOD = limit of detection (0.5 μg kg-1 for spirotetramat, spirotetramat-enol, 0.9 μg kg-1 for spirotetramat-ketohydroxy, 2.1 μg kg-1 for spirotetramat-MA-amide) 

na = not analysed 
– 100 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.3.1-23: Total average residues [μg kg-1] in soil samples (0 – 45 cm layer) collected from Washington cropped plot. 

Spirotetramat Spirotetramat-enol Spirotetramat-ketohydroxy Spirotetramat-MA-amide 

DAT 0 – 15 

cm 

15 – 30 

cm 

30 – 45 

cm 

Total 

(0 – 45 

cm) 

0 – 15 

cm 

15 – 30 

cm 

30 – 45 

cm 

Total 

(0 – 45 

cm) 

0 – 15 

cm 

15 – 30 

cm 

30 – 45 

cm 

Total 

(0 – 45 

cm) 

0 – 15 

cm 

15 – 30 

cm 

30 – 45 

cm 

Total 

(0 – 45 

cm) 

-4 < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD 

0 69.7 na na 69.7 24.1 na na 24.1 39.0 na na 39.0 < LOD na na < LOD 1 17.3 < LOD < LOD 17.3 8.7 < LOD < LOD 8.7 84.6 < LOD < LOD 84.6 < LOD < LOD < LOD < LOD 3 0.5a < LOD < LOD 0.5a 4.7a < LOD < LOD 4.7a 83.4 < LOD < LOD 83.4 3.0a < LOD < LOD 3.0a7 < LOD < LOD < LOD < LOD 3.6a < LOD < LOD 3.6a 40.5 < LOD < LOD 40.5 2.3a < LOD < LOD 2.3a

14 < LOD < LOD < LOD < LOD 2.1a < LOD < LOD 2.1a 14.2 < LOD < LOD 14.2 < LOD < LOD < LOD < LOD 28 < LOD < LOD < LOD < LOD 1.9a < LOD < LOD 1.9a 3.2a < LOD < LOD 3.2a < LOD < LOD < LOD < LOD 58 < LOD < LOD < LOD < LOD 0.9a < LOD < LOD 0.9a < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD 

120 < LOD < LOD < LOD < LOD 0.7a < LOD < LOD 0.7a < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD 175 < LOD < LOD < LOD < LOD 0.9a < LOD < LOD 0.9a < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD 269 na na na na na na na na na na na na na na na na 363 na na na na na na na na na na na na na na na na 538 na na na na na na na na na na na na na na na na 

a Residues < LOQ (5 μg kg-1) 

LOD = limit of detection (0.5 μg kg-1 for spirotetramat, spirotetramat-enol, 0.9 μg kg-1 for spirotetramat-ketohydroxy, 2.1 μg kg-1 for spirotetramat-MA-amide) 

na = not analysed 
– 101 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.3.1-24: Average residues [μg kg-1] of spirotetramat and parent equivalents of 

spirotetramat-enol, spirotetramat-ketohydroxy and spirotetramat-MA-amide in soil samples from 0 – 

45 cm colleted from Washington bare ground and cropped plots. 

Bare ground plot Cropped plot 

DAT Spirotetramat 

Spirotetramatenol 

Spirotetramatketohydroxy SpirotetramatMAamide 

Total Spirotetramat 

Spirotetramatenol 

Spirotetramatketohydroxy SpirotetramatMAamide 

Total 

-4 < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD < LOD 

0 85.4 23.9 43.1 < LOD 152.4 69.7 29.9 45.9 < LOD 145.5 

1 28.5 10.2 93.5 < LOD 132.2 17.3 10.8 99.5 < LOD 127.6 

3 2.1 8.2 84.5 3.9 98.7 0.5 5.8 98.1 3.3 107.7 

7 0.6 5.0 62.8 < LOD 68.4 < LOD 4.5 47.7 2.6 54.8 

14 < LOD 3.0 31.3 < LOD 34.3 < LOD 2.6 16.7 < LOD 19.3

28 < LOD 2.1 14.6 < LOD 16.7 < LOD 2.4 3.8 < LOD 6.2 

58 < LOD 0.9 6.2 < LOD 7.1 < LOD 1.1 < LOD < LOD 1.1 

120 < LOD < LOD 3.8 < LOD 3.8 < LOD 0.9 < LOD < LOD 0.9

175 < LOD 1.5 3.3 < LOD 4.8 < LOD 1.1 < LOD < LOD 1.1 

269 na na na na na na na na na na 

363 na na na na na na na na na na 

538 na na na na na na na na na na 

LOD = limit of detection (0.5 μg kg-1 for spirotetramat, spirotetramat-enol, 0.9 μg kg-1 for spirotetramat-ketohydroxy, 2.1 μg kg-1 for 

spirotetramat-MA-amide) 

na = not analysed 

Table B.8.1.3.1-25: Calculated dissipation half-life [days] of spirotetramat, combined residues of 

spirotetramat-enol and spirotetramat-ketohydroxy, and total combined residues in Washington bare 

ground and cropped soil plots (non-normalized) based on SFO kinetics. 

Study site Substance DT50

[days] 

DT90

[days] R

2

χ

2

error 

[%] 

Formation 

fraction 

[0 ... 1] 

Kinetics 

Spirotetramat 0.4 1.4 0.99 1.6 - SFO 

Sum of spirotetramat-enol + 

spirotetramat-ketohydroxy 5.2 17.4 0.98 19.5 1a

 All SFO in series 

Washington, 

bare ground 

plot 

Total combined residuesa 6.3 21.0 0.98 8.5 - SFO 

Spirotetramat 0.3 1.1 0.99 0.4 - SFO 

Sum of spirotetramat-enol + 

spirotetramat-ketohydroxy 4.6 15.4 0.98 7.4 1a

 All SFO in series Washington, 

cropped plot 

Total combined residuesa 5.0 16.7 0.98 5.0 - SFO 

a

 No additional pathways to sink assumed, therefore fixed to 1 during modelling

b

 Total combined residues: sum of spirotetramat, spirotetramat-enol, spirotetramat-ketohydroxy and spirotetramat-MA-amide 

Conclusion:

Spirotetramat rapidly dissipated under field conditions on bare ground and cropped plots with a DT50 of 0.4 

and 0.3 days, respectively (SFO kinetics, R2

 = 0.99, χ

2

 error ≤ 1.6 %). Respective DT90 values were 1.4 and 

1.1 days, respectively. Total combined residues dissipated with a DT50 of 6.3 and 5.0 days in bare ground 

and cropped plots, respectively. Residues of spirotetramat and its transformation products were not found 

> LOD below the 0 – 15 cm soil layer. 

Reviewer comments:

• Owing to the distinct storage instability of spirotetramat-enol (degrading to spirotetramat-ketohydroxy 

and bound to the soil matrix during freeze storage, see Netzband, 2006), residues of spirotetramatenol and spirotetramat-ketohydroxy should not be evaluated individually. 
– 102 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

B.8.1.3.2 Soil residue testing 

This point is covered by point B.1.1.3.1. 

B.8.1.3.3 Soil accumulation testing on relevant soils 

This point is covered by point B.1.1.3.1. 

B.8.1.3.4 Supplemental studies 

Reference: In house laboratory validation of an analytical method for the determination 

of BYI08330 and its metabolites BYI08330-enol, BYI08330-ketohydroxy and 

BYI08330-MA-amide in soil and sediment by LC-MS/MS 

Author(s), year: Netzband, D. J., 2006a 

Study/Report number: M-277365-01-1, RAFNX012 

Guideline(s): US-EPA Test Guidelines OPPTS 850-7100 (1996), OPPTS 860.1340 (1996) 

GLP: Yes 

Deviations: None 

Validity: Study considered acceptable 

Material and methods:

Test substances: Spirotetramat, spirotetramat-enol, spirotetramat-ketohydroxy, spirotetramat-MAamide (all unlabelled) 

Internal standard: 13C3-Spirotetramat, 13C3-spirotetramat-enol, 13C3-spirotetramat-ketohydroxy, 

13C3-spirotetramat-MA-amide 

Test system: Two soil samples (North Rose, New York, study nr. MEFNY004, Lenz, 2006a, and 

Ephrata, Washington, study nr. MEFNY003, Lenz, 2006d) and one sediment 

(Columbia, SC); 13 replicates for each soil, 7 replicates for the sediment. 

The soils used are from the field dissipation study sites (B.8.1.3.1). The soil 

properties are already listed in monograph tables (New York: Table B.8.1.3.1-2, 

Washington: Table B.8.1.3.1-19) 

A detailed sediment characterisation (SC) is not available since that was not 

mentioned in the respective study protocol 

Fortification: 5 and 25 μg kg-1 of each analyte separately 

Internal laboratory 

validation: 

An Intern laboratory validation (ILV) on the method has been performed with the 

soils ‘Hoefchen’ and ‘Laacherhof’, spiking level 5 and 50 μg kg-1 (for details refer 

to following study) 

Sample processing: Analytical method FN-002-S05-02 (updated to FN-002-S05-03): 20 g of soil are 

mixed with [25 mL of a solution of ethyl acetate (5 %, v/v) and cysteine 

hydrochloride (8 g L-1) in water, 0.5 mL formic acid, 25 mL acetonitrile], fortified 

with 1 ml of 13C internal standard solution and extracted by microwave extraction 

(70 °C, 30 min). Extraction (without addition of internal standard) is repeated once. 

Following extraction samples are filtered (0.45 μm) to await LC/MS/MS analysis. 

Analytical techniques: LC/MS/MS (screening for spirotetramat-enol dimer 1 and 2 possible) 

Limit of detection 

(LOD): 

Defined as: (standard deviation (fortification 5 μg kg-1) × t0.99) + average apparent 

residue in untreated control; 

where t0.99 is the one-tailed t-statistic at the 99 % confidence level of n-1 replicates 

(i.e. 2.68 in case of n = 13 and 3.14 in case of n = 7) 
– 103 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Limit of quantification 

(LOQ): 

Defined as: (standard deviation (fortification 5 μg kg-1) × 5) + average apparent 

residue in untreated control 

Findings:

Calibration solutions of each analyte are stable over a minimum of 4 months when refrigerated. 

Table B.8.1.3.4-1: Mean recover and relative standard deviation (RSD) of analytes of freshly spiked 

soil and sediment samples. 

Soil Sediment Analyte Spiking level 

[μg kg-1] Overall mean [%] RSD [%] Overall mean [%] RSD [%] 

5 101 3.6 106 3.1 Spirotetramat 

25 106 1.6 108 3.2 

5 93 16.9 108 16.2 Spirotetramat-enol 

25 84 11.7 84 3.9 

5 98 6.9 110 5.6 Spirotetramat-ketohydroxy 

25 103 5.7 105 7.2 

5 105 3.3 117 3.4 Spirotetramat-MA-amide 

25 103 3.5 108 5.9 

Table B.8.1.3.4-2: Calculated LODs [μg kg-1] and LOQs [μg kg-1] for spirotetramat, spirotetramat-enol, 

spirotetramat-ketohydroxy and spirotetramat-MA-amide in soil and sediment samples. 

Matrix Analyte Calculated LOD [μg kg-1] Calculated LOQ [μg kg-1] 

Spirotetramat 0.5 0.9 

Spirotetramat-enol 0.5 0.9 

Spirotetramat-ketohydroxy 2.1 3.9 

Soil 

Spirotetramat-MA-amide 0.9 1.7 

Spirotetramat 0.5 0.8 

Spirotetramat-enol 0.6 1.0 

Spirotetramat-ketohydroxy 2.7 4.4 

Sediment 

Spirotetramat-MA-amide 1.0 1.5 

Table B.8.1.3.4-3: Results (mean recover and relative standard deviation, RSD) of the ILV using the 

soils ‘Hoefchen’ and ‘Laacherhof’ freshly spiked with each analyte (overall mean of two spiking 

levels, 5 and 50 μg kg-1). 

Hoefchen Laacherhof Analyte 

Overall mean [%] RSD [%] Overall mean [%] RSD [%] 

Spirotetramat 94 1.8 92 1.4 

Spirotetramat-enol 91 2.8 91 1.7 

Spirotetramat-ketohydroxy 85 1.7 83 2.8 

Spirotetramat-MA-amide 89 13.7 94 13.1 

Conclusion:

The analytical method FN-002-S05-02 (updated to FN-002-S05-03 after revision) is suitable for the 

determination of spirotetramat and its metabolites spirotetramat-enol, spirotetramat-ketohydroxy and 

spirotetramat-MA-amide in soil and sediment by LC/MS/MS. The average recoveries for all analytes were 

between 70 and 120 % with a relative standard deviation (RSD) of less than 20 %. The method was shown 

capable of quantifying spirotetramat and its metabolites at the targeted LOQ of 5 μg kg-1. 

Reviewer comments:

• Details on the ILV method using the soils ‘Hoefchen’ and ‘Laacherhof’ are given in the following OLV 

study report. 
– 104 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Reference: Independent laboratory validation of method FN-002-S05-02 for the 

determination of BYI08330 and its metabolites BYI08330-enol, BYI08330-

keto-hydroxy and BYI08330-MA-amide in soil and sediment by LC/MS/MS 

Author(s), year: Brumhard, B., 2006 

Study/Report number: M-276038-01-2, MR-06/037 

Guideline(s): EC Guidance Document SANCO/825/00 rev. 7 (2004); 

Commission Directive 96/46/EC amending Council Directive 91/414/EEC (1996); 

BBA Guideline: Residue Analytical Methods for Post-Registration Control 

Purposes (1998); 

US EPA Residue Chemistry Test Guidelines, OPPTS 860.1430 (1996); 

US EPA Ecological Effects Test Guidelines, OPPTS 850.7100 (1996) 

GLP: Yes 

Deviations: None 

Validity: Study considered acceptable 

Material and methods:

Test substances: Spirotetramat, spirotetramat-enol, spirotetramat-ketohydroxy, spirotetramat-MAamide (all unlabelled) 

Internal standard: 13C3-Spirotetramat, 13C3-spirotetramat-enol, 13C3-spirotetramat-ketohydroxy, 

13C3-spirotetramat-MA-amide 

Test system: • ‘Hoefchen’ soil, silt loam (USDA), 1.58 % Corg

• ‘Laacherhof’ soil, sandy loam (USDA), 2.06 % Corg

For a detailed characterization of these soils, which were also used in several 

laboratory studies, refer to B.1.1.1. 

Fortification: 5 and 50 μg kg-1 of each analyte separately 

Sample processing: Analytical method FN-002-S05-02: 20 g of soil are mixed with [25 mL of a solution 

of ethyl acetate (5 %, v/v) and cysteine hydrochloride (8 g L-1) in water, 0.5 mL 

formic acid, 25 mL acetonitrile], fortified with 1 ml of 13C internal standard solution 

and extracted by microwave extraction (70 °C, 30 min). Extraction (without 

addition of internal standard) is repeated once. Following extraction samples are 

filtered (0.45 μm) to await LC/MS/MS analysis. 

Analytical techniques: LC/MS/MS 

LOQ: 5 μg kg-1 each 

Findings:

Table B.8.1.3.4-4: Recovery rates of spirotetramat, spirotetramat-enol, spirotetramat-ketohydroxy and 

spirotetramat-MA-amide. 

Spirotetramat Spirotetramatenol 

Spirotetramatketohydroxy SpirotetramatFortification MA-amide 

[μg kg-1] Soil 

Mean 

[%] 

RSD 

[%] 

Mean 

[%] 

RSD 

[%] 

Mean 

[%] 

RSD 

[%] 

Mean 

[%] 

RSD 

[%] 

5 ‘Hoefchen’ 95 2.1 93 1.2 85 2.2 78 1.6 

5 ‘Laacherhof’ 93 0.7 92 1.9 85 2.9 83 2.5 

5 Mean 94 1.8 92 1.8 85 2.5 80 3.9 

10 ‘Hoefchen’ 93 1.1 89 1.3 85 1.2 101 1.2 

10 ‘Laacherhof’ 92 1.7 91 1.5 82 2.1 106 1.9 

10 Mean 92 1.7 90 1.8 83 2.1 103 3.0 

Overall mean 93 1.9 91 2.3 84 2.4 92 13.3 
– 105 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Conclusion:

The obtained data demonstrate the successful validation of the analytical method FN-002_s05-02 for the

determination of spirotetramat and its metabolites spirotetramat-enol, spirotetramat-ketohydroxy and 

spirotetramat-MA-amide in soil. Overall mean recoveries were within a range of 80 – 94 % and thus in full 

compliance with the guideline requirements. No significant changes were made to the method. The method

is considered applicable as an enforcement method. 

Comments (RMS):

None 

Reference: Stability of BYI08330, BYI08330-enol, BYI08330-ketohydroxy and BYI08330-

MA-amide in soil during frozen storage, USA, 2005 (reported through a 

maximum of 334 days storage) 

Author(s), year: Netzband, D., 2006b 

Study/Report number: M-277371-01-1, RAFNX018 

Guideline(s): Residue Chemistry Test Guidelines, OPPTS 860.1380 Storage Stability 

GLP: Yes 

Deviations: None 

Validity: Study considered acceptable 

Material and methods:

Test substances: Experiment 1: Spirotetramat, spirotetramat-enol, spirotetramat-ketohydroxy and 

spirotetramat-MA-amide (all unlabelled) 

Experiment 2: [Azaspirodecenyl-3-14C]-spirotetramat-enol, purity 97.6 %, 

ID No. C-1067, 2.10 MBq mL-1

Internal standard: 13C3-spirotetramat, 13C3-spirotetramat-enol, 13C3-spirotetramat-ketohydroxy and 

13C3-spirotetramat-MA-amide 

Test soils: Soils from field trials: 

• North Rose, New York (study nr. MEFNY004, Lenz, 2006a) 

• Oviedo, Florida (study nr. MEFNX055, Lenz, 2006b) 

• Fresno, California (study nr. MEFNY002, Lenz, 2006c) 

• Ephrata, Washington (study nr. MEFNY003, Lenz, 2006d) 

Fortification: Experiment 1: 20 g soil fortified to a level of 25 μg kg-1 with each analyte 

separately 

Experiment 2: 5 g soil fortified with 10.4 kBq 14C-spirotetramat-enol 

Sample set: Both experiments: 

• Control samples 

• Fortified samples (storage samples) 

• Freshly fortified samples (for each analysis date)

Storage conditions: Experiment 1: Fortified soil samples (with non-labelled test items) were stored 

frozen at -26.8 to 1.3 °C (mean -22.7 °C) over a period of 334 

days 

Experiment 2: Fortified soil samples (with 14C-spirotetrmat-enol) were stored 

frozen at -21.7 to -15.8 °C (mean -19.1 °C) over a period of 20 

days 

Sample processing: Experiment 1/Experiment 2: Soils were extracted with an acidic extraction 

solution in the presence of cysteine hydrochloride and utilizing 

microwave extraction. Samples were fortified with internal 13C 

standard. Sample aliqouts were analyzed by LC/MS/MS
– 106 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

(analytical method FN-002-S05-03) 

Experiment 2: Soil residues after extraction were radio-assayed by combustionLSC. 

Analytical techniques: Experiment 1: LC/MS/MS 

Experiment 2: LSC, HPLC-UV/RAD 

Findings:

Experiment 1: 

Spirotetramat and its metabolites spirotetramat-ketohydroxy and spirotetramat-MA-amide showed no 

evidence of any degradation in the four soils during a maximum storage interval of 334 days in frozen 

storage. However, reduced spirotetramat-enol recovery was observed for each of the aged soils. Inspection 

of the results showed that significant spirotetramat-enol loss occurred during the first month of storage after 

which spirotetramat-enol loss continued at slower rate. 

Table B.8.1.3.4-5: Experiment 1: Mean recovery [% of applied] of spirotetramat, spirotetramat-enol, 

spirotetramat-ketohydroxy and spirotetramat-MA-amide from frozen stored samples (corrected for 

fresh recovery). 

Soil DAT Spirotetramat Spirotetramat-enol Spirotetramatketohydroxy 

Spirotetramat-MAamide 

0 94 66 94 93 

29 87 43 92 112 

70 88 51 101 122 

New York 

334 83 37 101 107 

0 105 100 84 103 

30 99 67 81 118 

70 109 57 80 120 

Florida 

329 100 24 81 106 

0 102 72 74 95 

28 101 45 74 127 

68 97 41 76 116 

California 

325 101 55 75 108 

0 101 93 91 95 

24 101 47 89 128 

71 97 32 43 116 

Washington 

329 104 43 83 100 

The results of the aged samples fortified with spirotetramat-enol were further examined and it was observed 

that while no spirotetramat or spirotetramat-MA-amide residues were observed, spirotetramat-ketohydroxy 

was present in each of the samples. After combining spirotetramat-enol and spirotetramat-ketohydroxy 

(expressed as spirotetramat-enol equivalents) recoveries obtained were still lower than expected (57 – 64 % 

of applied by 334 DAT). 
– 107 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.3.4-6: Experiment 1: Mean recovery [μg kg-1] of spirotetramat-enol and spirotetramatketohydroxy in samples fortified with spirotetramat-enol (25 μg kg-1) and stored frozen (corrected for 

fresh recovery). 

Spirotetramat-enol Spirotetramatketohydroxy Total Soil DAT 

Spirotetramat-enol equivalents [μg kg-1] [% of applied] 

0 17.7 0.6 18.3 68 

29 12.2 1.6 13.9 49 

70 14.0 1.4 15.4 56 

New York 

334 7.6 4.9 12.6 61 

0 23.2 0.3 23.5 102 

30 17.5 2.0 19.5 75 

70 15.5 2.4 17.9 66 

Florida 

329 5.2 8.7 13.9 64 

0 15.7 0.9 16.6 76 

28 11.9 1.7 13.6 51 

68 10.8 1.6 12.4 47 

California 

325 12.5 1.5 13.9 62 

0 20.8 0.3 21.2 95 

24 11.7 3.4 15.1 61 

71 8.5 3.2 11.6 44 

Washington 

329 9.1 2.9 12.0 57 

Experiment 2: 

As a supplement to these results, a shorter 14C-spirotetramat-enol storage stability trial was performed in 

order to determine the level of any un-extracted residues present in the soil and to determine the presence of 

any additional analytes formed by the degradation of spirotetramat-enol while stored frozen. 

The results show that the mass balance of the radioactivity was in a range of 92 – 102 % of AR, by 20 DAT 

of frozen storage, between 3 – 15 % of AR remained bound to the soil (NER). Freshly spiked samples only 

contained spirotetramat-enol. Aged samples contained both spirotetramat-enol and spirotetramatketohydroxy. No additional peaks were observed in the aged samples. 

Table B.8.1.3.4-7: Experiment 2: Mean recovery [% of applied] of spirotetramat-enol, spirotetramatketohydroxy, total extractable residues and non extractable residues in samples fortified with 14Cspirotetramat-enol and stored frozen (corrected for fresh recovery). 

Soil DAT Spirotetramatenol 

Spirotetramatketohydroxy Total Extracted Bound Total recovery 

0 97 0 na na na 

New York 3 55 14 86 9 94 

20 43 14 85 15 100 

0 86 0 na na na 

Florida 3 38 40 89 3 93 

20 29 44 94 3 92 

0 94 0 na na na 

California 3 52 16 90 6 93 

20 44 14 88 8 100 

0 95 0 na na na 

Washington 3 47 43 87 7 96 

20 19 54 92 8 102 
– 108 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Conclusion:

Spirotetramat and its metabolites spirotetramat-ketohydroxy and spirotetramat-MA-amide showed no 

evidence of any degradation in the four soils during a maximum storage interval of 334 days in frozen 

storage. Spirotetramat-enol recoveries significantly declined during storage (24 – 55 % of applied by 334 

DAT), with the majority of the loss occurring during the first 30 days of storage (43 – 67 % of applied by 30 

DAT). The primary cause of these low recoveries was degradation of spirotetramat-enol to spirotetramatketohydroxy (7 – 40 % equivalents of applied by 334 DAT) and binding of the analyte to soil. 

Reviewer comments:

• Owing to the distinct storage instability of spirotetramat-enol, kinetic evaluation of residues of 

spirotetramat-enol and spirotetramat-ketohydroxy in all US field trials is not advisable. Since it was

shown, that during sample storage most of spirotetramat-enol degrades into spirotetramatketohydroxy, it is seems more appropriate to calculate an overall DT50 for the combined residues of 

spirotetramat-enol and spirotetramat-ketohydroxy. 

• The submitted storage stability study report until 334 days of storage is an interim report. The 

storage stability studies using non-radiolabelled (for all analytes) and radiolabelled material (only for 

BYI08330-enol) are ongoing. The 786 days of storage will be completed in November 2007 for the 

study involving non-radiolabelled material and September 2008 for the study involving radiolabelled 

material. 

Reference: Environmental behaviour of spirotetramat and its metabolites in U.S. field 

dissipation trials 

Author(s), year: Röpke, B., Ramanarayanan, T., 2007

Study/Report number: -, MEF-07/120 

Guideline(s): Calculations - not applicable 

GLP: Calculations - not applicable 

Deviations: Calculations - not applicable 

Validity: Study considered as additional information, only – study not essential

Material and methods:

A kinetic data package for spirotetramat (Ramanarayanan, 2006) and its soil metabolites spirotetramat-enol, 

spirotetramat-ketohydroxy and spirotetramat-MA-amide (Röpke, 2006a) was derived from laboratory aerobic 

soil degradation data (Babczinski, 2005 and 2006b) for use as input parameters in environmental fate 

models, and in the environmental risk assessment. In the laboratory study spirotetramat-enol showed a very 

rapid initial degradation phase which changed into a slow degradation after approximately one day. This 

extremely biphasic degradation behaviour was then described by a single first order reversible binding (SFORB) model. Due to this extreme biphasic degradation pattern it was not possible to derive 

adsorption/desorption values for spirotetramat-enol with a standard batch equilibrium study according to 

OECD 107. Hence, KOC values for equilibrium and non-equilibrium sorption were derived from a column 

leaching study (Babczinski, 2006c). The SFO-RB kinetic model and the equilibrium sorption KOC from the 

column leaching study were then converted into a consistent kinetic sorption model according to the 

PEARLneq (FOCUS, 2000) model which can be implemented in environmental fate models such as PEARL. 

The object of this study was to check whether the parameter set, used in predictive environmental simulation 

models, adequately describes the behaviour of spirotetramat and metabolites under realistic outdoor 

conditions. Soil residue measurements of spirotetramat and metabolites were available from four terrestrial 

field dissipation trials conducted in the U. S. (Lenz, 2006a, 2006b, 2006c, 2006d). The terrestrial field 

dissipation study in Florida was not used in this exercise owing to the extreme soil and weather conditions 

(extreme rainfall event in hurricane season, extremely light soil, 95 % sand, 0.2 % Corg). 
– 109 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Flow and transport simulations for the respective field sites in consideration of their environmental 

parameters (soil, climate) were performed with FOCUS PEARL 2.2.2. Results were compared to the 

measured concentrations of spirotetramat and its metabolites from the respective field studies. 

Figure B.8.1.3.4-1: Multi-compartment approach (including SFO-RB kinetics for spirotetramat-enol) 

used for modelling the behaviour of spirotetramat and metabolites in three US field trials 

(implemented into PEARL). 

Spirotetramat (SFO) 

Spirotetramat-enol (mobile) 

Spirotetramat-ketohydroxy (SFO) 

Spirotetramat-MA-amide (SFO) 

Sink 

100 % 

26 % 74 % 

100 % 

100 % 

Spirotetramat-enol (protected) 

SFORB 
– 110 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.3.4-8: Parameter set used for modelling the behaviour of spirotetramat and metabolites in 

three US field trials. 

Compound Parameter Value Remarks 

Mole mass [g mol-1] 373.5 

Soil DT50 [days] 0.13 SFO, normalized, geometric mean, n = 4 

KFOC [L kg-1] 281 Batch, arithmetic mean, n = 5 

1/n 0.94 Batch, arithmetic mean, n = 5 

Water solubility [mg L-1] 29.9 20 °C, pH 7 

Vapour pressure [Pa] 5.6 × 10-9 20 °C 

Spirotetramat 

Plant uptake 0.5 

Mole mass [g mol-1] 301.4 

Soil DT50 [days] 0.10 

SFO, normalized, geometric mean, n = 4, 

original value of 0.04 days substituted by the 

lowest limit of 0.1 days in PEARL (see 

comments) 

Formation fraction [%] 

(from parent) 100 Not known, conservative assessment 

fne [-] 99 

Kinetic sorption parameter (SFO-RB), 

arithmetic mean, n = 4, original value of 377 

substituted by the upper limit of 99 in PEARL 

(see comments) 

kd [days-1] 0.0159 Kinetic sorption parameter (SFO-RB), 

geometric mean, n = 4 

KOC [L kg-1] 55 Column leaching, arithmetic mean, n = 4 

1/n 1.0 Set to 1.0 to adequately account for SFO-RB 

kinetics, conservative assessment 

Water solubility [mg L-1] 2700 20 °C, pH 7 

Vapour pressure [Pa] 3.64 × 10-10 25 °C (US EPA 2000) 

Spirotetramatenol 

Plant uptake 0.5 

Mole mass [g mol-1] 317.4 

Soil DT50 [days] 3.8 SFO, normalized, geometric mean, n = 4 

Formation fraction [%] 

(from spirotetramat-enol) 26 

KFOC [L kg-1] 63.7 Batch, arithmetic mean, n = 5 

1/n 0.92 Batch, arithmetic mean, n = 5 

Water solubility [mg L-1] 288 20 °C, pH 7 

Vapour pressure [Pa] 2.21 × 10-10 25 °C (US EPA 2000) 

Spirotetramatketohydroxy 

Plant uptake 0.5 

Mole mass [g mol-1] 335.4 

Soil DT50 [days] 1.0 SFO, normalized, geometric mean, n = 4 

Formation fraction [%] 

(from Spirotetramatketohydroxy) 

100 Fixed to 100 % during fitting procedure 

KFOC [L kg-1] 9.3 Batch, arithmetic mean, n = 5 

1/n 0.95 Batch, arithmetic mean, n = 5 

Water solubility [mg L-1] 69.74 20 °C, pH 7 

Vapour pressure [Pa] 1.56 × 10-11 25 °C (US EPA 2000) 

SpirotetramatMA-amide 

Plant uptake 0.5 

Table B.8.1.3.4-9: Parameterization of soil and climate. 

Simulation domain, discretisation and boundary conditions 122 cm soil profile, 2.5 cm intervals, free drainage 

Soil parameterization Hydraulic parameter (van Genuchten and Ksat parameter) 

derived by ROSETTA 

Vegetation Bare ground and cropped plots evaluated separately 

Temperature and moisture normalization FOCUS default values, Q10 = 2.2, 

Walker exponent of moisture response = 0.7 
– 111 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Findings:

A

B

C 

Figure B.8.1.3.4-2: Measured (squares) and modelled (lines) amounts of spirotetramat (A), of 

combined residues of spirotetramat-enol and spirotetramat-ketohydroxy (B) and of spirotetramatMA-amide (C) in 0 – 15 cm soil depth of the California site (bare ground plots). 
– 112 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

A 

B 

C 

Figure B.8.1.3.4-3: Measured and modelled amount of spirotetramat (A), of combined residues of 

spirotetramat-enol and spirotetramat-ketohydroxy (B) and of spirotetramat-MA-amide (C) in 0 – 15 cm 

soil depth of the New-York site (bare ground plots). 
– 113 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

A 

B 

C 

Figure B.8.1.3.4-4: Measured and modelled amounts of spirotetramat (A), of combined residues of 

spirotetramat-enol and spirotetramat-ketohydroxy (B) and of spirotetramat-MA-amide (C) in 0 – 15 cm 

soil depth of the Washington site (bare ground plots). 
– 114 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Conclusion:

The comparison of the measured soil residue of spirotetramat and its metabolites from three US field studies 

to simulated soil concentrations based on the parameter set derived by Ramanarayanan (2006) and Röpke 

(2006a) overall yielded good agreement between the uncalibrated model simulations and measurements. No

significant residues of the active ingredient or its metabolites below 15 cm of depth were predicted by the 

model and this was confirmed by the field study data. In general it can be concluded that the environmental 

behaviour of spirotetramat and its metabolites under field conditions is adequately and rather conservatively 

described by the environmental fate (adsorption and degradation) data and kinetic sorption model which was 

derived from laboratory studies and used in the environmental exposure assessment for the EU calculations. 

Reviewer comments:

• Study not considered essential. Study results included for additional information only. 

• Owing to the low stability of spirotetramat-enol even under frozen storage conditions (degrading to 

spirotetramat-ketohydroxy and formation of NER), modelled data for spirotetramat-enol and 

spirotetramat-ketohydroxy can be only compared to the combined residues of these two metabolites 

measured in the field trials. 

• Owing to numerical restrictions of the PEARL model, no longer DT50 values than 0.1 days (lower 

limit) and fne values of 99 (upper limit) can be used as substitutes in PEARL modelling. With this 

restricted parameter set as used in PEARL leaching assessments, the formation of spirotetramatketohydroxy is underpredicted by approx. 21 % on average. An increase in the formation fraction of 

spirotetramat-ketohydroxy by this magnitude is not expected to have a significant impact on the 

groundwater risk assessment (position paper, Hellpointner et al., 2007). 
– 115 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

B.8.1.3.5 Summary on field dissipation studies 

Four field dissipation studies (including bare and cropped soils) were conducted with spirotetramat on a 

range of soil types in the USA, representing rather worst-case scenarios in respect to degradation (low 

amounts of organic C) and leaching behaviour (sandy soils with low contents of clay). Spirotetramat was 

applied once at 439 g ai ha-1 (single application) formulated as the oil dispersion BYI08330 100 OD. 

Dissipation of spirotetramat in field trials was rapid with a dissipation half-life (DT50) in a range of 0.3 – 1.0 

day (SFO kinetics), respective DT90 values were in a range of 1.1 – 3.5 days. Since almost no transfer of 

spirotetramat into soil layers below 15 cm was observed and volatilization is considered to be minimal

(vapour pressure 5.6 × 10-9 Pa), dissipation of spirotetramat is considered more or less consistent with 

degradation. No differences were observed between bare ground and cropped plots. Owing to the short halflife of spirotetramat in soil, potential of accumulation and carry over of spirotetramat from one year to the 

other year is considered negligible. 

Quantification of metabolite residues in the field trial was strongly affected by the low storage stability of 

spirotetramat-enol. In soil storage experiments (spiked soil samples, stored over a time period of 334 days, 

using the same soils from the four field trials), it was demonstrated that spirotetramat-enol extensively 

degrades to spirotetramat-ketohydroxy and is also strongly bound to the soil (NER) even under frozen 

storage conditions. Decline of spirotetramat-enol was most pronounced during the first 30 days of storage. In 

this respect, residues of spirotetramat-enol found in the field trials (including sample storage time of several 

months) are likely to be significantly underestimated, whereas residues of spirotetramat-ketohydroxy are vice 

versa overestimated. Therefore, an individual kinetic evaluation of spirotetramat-enol and spirotetramatketohydroxy residues measured in the field trials is not advisable at all. Spirotetramat, spirotetramatketohydroxy and spirotetramat-MA-amide are considered stable under conditions of frozen storage. 

Based on combined residues of spirotetramat-enol and spirotetramat-ketohydroxy, DT50 values in a range of 

4.6 – 31.6 days were found (SFO kinetics). Respective DT90 values were in a range of 15.4 – 105 days. No 

significant differences were found between bare ground and cropped plots. 

Total combined residues (spirotetramat, spirotetramat-enol, spirotetramat-ketohydroxy and spirotetramatMA-amide) were found to dissipate with a DT50 in a range of 5.0 – 23.4 days (SFO kinetics), respective DT90

values were in a range of 16.7 – 77.8 days. No differences between plot treatments were found at all. 

Potential of carry over of any residue from one year to the other year is considered minimal. 

Residues of spirotetramat did not move below the surface layer (0 – 15 cm) in all sites, except Florida where 

residues of spirotetramat-enol and spirotetramat-ketohydroxy were detected above the LOQ (i.e. 5 μg kg-1) at 

15 – 30 cm layer between 1 and 7 DAT. Thereafter, residues completely degraded to less than LOQ and 

LOD. It should be noted that the Florida test site represents worst-case conditions with heavy rainfall, very 

light soil (95 % sand in the top layer) and low organic matter (0.2 %). Based on field dissipation data, 

leaching and groundwater contamination is not likely to occur after application of spirotetramat according to 

GAP. 

In order to validate degradation and kinetic adsorption/desorption parameters of spirotetramat and its

metabolites obtained in laboratory experiments, the US field trials conducted in California, New York and 

Washington were fully re-modelled with the identical parameter set as suggested for the groundwater risk 

assessment (implementing SFO-RB kinetics for spirotetramat-enol). From the close fit between measured 

and modelled data (uncalibrated model based on laboratory data), it can be concluded that the 

adsorption/desorption and degradation parameter set, suggested for the environmental risk assessment, 
– 116 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

adequately reflects the transport and degradation behaviour of spirotetramat and its metabolites under real 

field conditions. 
– 117 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.1.3.5-1: Summary on dissipation half-lives of spirotetramat in four US dissipation field trials (non-normalized data). 

Texture pH (CaCl2) pH (soil/water, 1/1, m/v) Organic C [%] Clay [%] Site Crop 

0 – 15 cm 

DT50

[days] 

DT90

[days] R2 χ

2 error 

[%] Kinetics 

‘New York’, US Bare ground Loamy sand 5.5 6.3 0.70 9 0.5 1.6 0.94 5.1 SFO 

Bare ground Sand - 7.1 0.23 2 0.9 2.9 0.96 2.2 SFO ‘Florida’, US Bush beans Sand - 7.1 0.23 2 1.0 3.3 0.96 0.4 SFO Bare ground Sandy loam - 7.2 0.29 9 1.0 3.5 0.98 12.1 SFO ‘California’, US Tomatoes Sandy loam - 6.8 0.29 7 1.0 3.4 0.97 12.6 SFO Bare ground Sandy loam - 8.1 0.41 5 0.4 1.4 0.99 1.6 SFO ‘Washington’, US Onions Loamy sand - 8.0 0.35 5 0.3 1.1 0.99 0.4 SFO

Geometric mean (EU) 0.7 2.2 - - - 80th %ile (PMRA) 1.0 3.4 - - - 90th %ile of C.I. on meana (US-EPA) 0.9 3.0 - - - a Calculated by [arithmetic mean + (t90,n-1 × SD) / n0.5], whereby t90,n-1 = one-sided students t value at α = 0.1, SD = standard deviation and n = number of data available Table B.8.1.3.5-2: Summary on dissipation half-lives of combined residues of spirotetramat-enol and spirotetramat-ketohydroxy and of total combined 

residues in four US dissipation field trials (0 – 15 cm, non-normalized data). 

Sum of spirotetramat-enol and spirotetramat-ketohydroxy Total combined residues Site Crop DT50 [days] DT90 [days] χ2 error [%] R2 DT50 [days] DT90 [days] χ2 error [%] R2

‘New York’, US Bare ground 31.6 105 16.6 nc 23.4 77.8 16.4 0.93 

Bare ground 6.6 21.9 26.9 nc 7.6 25.3 22.3 0.86 ‘Florida’, US Bush beans 4.8 16.0 26.9 nc 5.7 19.0 18.7 0.90 Bare ground 7.6 25.4 14.8 0.94 8.4 27.9 11.3 0.95 ‘California’, US Tomatoes 8.7 28.9 22.4 0.90 10.2 33.9 13.7 0.91 Bare ground 5.2 17.4 19.5 0.98 6.3 21.0 8.5 0.98 ‘Washington’, US Onions 4.6 15.4 7.4 0.98 5.0 16.7 5.0 0.98 

Geometric mean (EU) 7.7 25.6 - - 8.3 27.7 - - 80th %ile (PMRA) 8.5 28.2 - - 9.8 32.7 - - 90th %ile of C.I. on meana (US-EPA) 15.2 50.4 - - 13.0 43.2 - - nc denotes not calculated a Calculated by [arithmetic mean + (t90,n-1 × SD) / n0.5], whereby t90,n-1 = one-sided students t value at α = 0.1, SD = standard deviation and n = number of data available 
– 118 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

B.8.2 Adsorption, desorption and mobility in soil 

B.8.2.1 Mobility studies (OECD Annex IIA, 7.4, IIIA, 9.3) 

B.8.2.1.1 Adsorption and desorption of the active substance (OECD Annex IIA, 7.4.1) 

The adsorption/desorption of spirotetramat was investigated in one study using [3-14C] labelled parent. 

Reference: BYI08330: Adsorption/desorption in five soils 

Author(s), year: Haas, M., 2005 

Study/report number: M1311388-5, MEF-04/373 

Guideline(s): OECD Guidelines 106 (2000), US-EPA N 163-1 (1982), Canadian PMRA DACO 

8.2.4.2 (1987)1, Japanese MAFF New Test Guidelines for Supporting Registration 

of Pesticides (2000 and 2001) 

GLP: Yes 

Deviations: None 

Validity: Study considered acceptable 

Material and methods:

Test substance: [Azaspirodecenyl-3-14C]-spirotetramat, 3.67 MBq mg-1, 

> 98 % radiochemical purity (HPLC), batch BECH 1537 and 1597 

Reference substance: Spirotetramat (unlabelled), spirotetramat-enol, spirotetramat-ketohydroxy 

Soils: Air dried, 2-mm sieved 

Soil/solution ratio: 1/10, m/v 

Temperature: 20 ± 1 °C 

Test concentrations: 0.01, 0.03, 0.1, 0.3 and 1.0 mg L-1

in 0.01 M CaCl2 (containing 50 mg L-1 mercuric(II)chloride for sterilization) 

Co-solvent: None 

Pre-equilibration time: 48 hrs 

Equilibration time: 3 hrs for adsorption, 3 hrs for desorption (highest test concentration: 3 desorption 

cycles) 

Extraction: After adsorption remaining soil was extracted twice with 20 ml acetonitrile/water 

(1/1, v/v). After extraction the soil residues were radio-assayed by combustionLSC. 

Analytical techniques: LSC, HPLC-UV/RAD, HPLC-MS/MS(ESI) 

LOQ = 1 % of AR 

Calculations: The amount adsorbed was calculated by subtracting the equilibrium concentration 

in the solution from the initial concentration applied. 

The Freundlich adsorption isotherm is described as Cs = KF(ads) × Cw

(1/n), whereby 

Cs is the equilibrium concentration of the test item in the soil after adsorption 

[μg g-1], Cw the equilibrium concentration in the solution [μg mL-1], KF(ads) is the 

Freundlich adsorption coefficient and 1/n the Freundlich exponent. KF(ads) and 1/n 

were obtained by plotting log(Cs) vs. log(Cw) to give 1/n as the slope and 

log(KF(ads)) as the intercept of the linear regression. Desorption (based on the 

desorption constant KF(des)) was calculated in a similar way. 

In addition, the linear adsorption coefficient Kd(ads) was obtained by linear 

regression plotting CW vs. CS without data transformation (calculated by the 

reviewer). 

 

1

 The Canadian guideline is improperly cited in the study report. It should be cited as: Agriculture Canada (1987) Trade 

Memorandum T-1-255, Guidelines for Determining Environmental Chemistry and Fate of Pesticides. 
– 119 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Based on the organic carbon [%], the Freundlich adsorption coefficient is 

expressed as KFOC(ads) = (KF(ads) × 100) / Corg (Freundlich desorption and linear 

adsorption/desorption coefficients are expressed in a similar way). 

Table B.8.2.1.1-1: Physico-chemical characteristics of test soils used for adsorption/desorption of 

spirotetramat. 

Soil ‘Laacherhof 

AXXa’ 

‘Laacherhof 

AIII’ ‘Hoefchen’ ‘Molino’ ‘Saskatoon’ 

Batch ID 20040122 20030729 20040109 20030324 980803 

Geographic 

location 

Monheim/ 

NorthrhineWestfalia/ 

Germany 

Monheim/ 

NorthrhineWestfalia/ 

Germany 

Burscheid/ 

NorthrhineWestfalia/ 

Germany 

Pensacola 

Florida/ 

USA 

Saskatchewan/

Canada 

Texture (USDA) Loamy sand Sandy loam Silt loam Sandy loam Loam 

Soil taxonomic 

classification 

(USDA) 

Sandy, mixed, 

mesic Typic 

Cambudolls 

Loamy, mixed, 

mesic Typic 

Argudalfs 

Inseptic 

Hapludalf 

Fine-loamy, 

kaolinitic, 

thermic, Plinthic 

Kandiudults 

Orthic dark 

brown 

Sand (USDA) [%] 83.0 52.5 19.0 77.3 27.3 

Silt (USDA) [%] 10.0 30.9 66.0 12.7 48.3 

Clay (USDA) [%] 7.0 16.7 15.0 10.0 24.4 

pH (CaCl2) 6.1 6.8 5.9 5.4 4.7 

pH (water) 6.5 7.4 6.3 6.1 5.2 

pH (KCl) 6.2 6.9 5.8 nd nd 

Organic carbon [%] 2.38 0.87 2.33 0.93 2.33 

CEC [meq kg-1] 110 48 129 60 199 

WHC (0.33 bar) [%] 12.6 20.3 21.4 18.4 nd 

MWHC [%] 34.4 37.3 63.1 nd nd 

Findings:

In the pre-test, it was obvious that spirotetramat rapidly degrades to spirotetramat-enol in the presence of 

soil. Hence, to prevent microbial degradation of spirotetramat the test soils were sterilized by soil 

equilibration in 0.01 M CaCl2 containing 50 mg L-1 mercuric(II)chloride for two days. Under sterile conditions 

(preliminary parental mass balance test), spirotetramat was stable for 3 hrs of adsorption equilibrium time in 

all soils (test item recovery: 91.8 – 93.7 % of AR) with the exception of the ‘Hoefchen’ soil, where approx. 10 

% of the test-item was degraded into spirotetramat-enol. The test item did not adsorb to the wall surface of 

the test vessel. 

The overall material balance for all concentrations for individual samples was in the range of 72.0 – 125.1 % 

of AR with a mean of 97.6 % of AR. After 3 hrs of equilibration 17.2 – 46.7 % of AR was adsorbed to the test 

soils. The calculated adsorption constants KF(ads) of the Freundlich isotherms for the five test soils were in a 

range of 3.70 – 4.79 L kg-1, the Freundlich exponent 1/n was in a range of 0.823 – 1.042. The desorption 

KF(des) values were 4 – 8 times higher than those obtained for adsorption indicating a strong binding of the 

test substance once adsorbed to the soil. 
– 120 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.2.1.1-2: Preliminary test I: Equilibration test adsorption. Adsorption of the test-item after a 

shaking period of 0 – 24 hrs (expressed as [% of AR] remaining in the solution and purity [% ai]), 

soil/solution ration 1/10 (m/v), test concentration 1.08 mg L-1, containing 50 mg L-1

mercuric(II)chloride for sterilization. 

‘Laacherhof AXXa’ ‘Laacherhof AIII’ ‘Hoefchen’ ‘Molino’ ‘Saskatoon’ HAT 

[% of AR] [% ai] [% of AR] [% ai] [% of AR] [% ai] [% of AR] [% ai] [% of AR] [% ai] 

0 74.1 100.0 78.1 100.0 69.8 100.0 79.2 100.0 64.9 100.0 

0.5 72.9 100.0 74.9 100.0 65.7 97.5 76.9 100.0 62.6 100.0 

1 72.9 100.0 68.7 100.0 64.6 91.0 75.2 100.0 57.9 100.0 

3 66.1 98.0 70.8 100.0 66.4 88.0 76.1 100.0 58.1 100.0 

6 71.4 100.0 73.0 100.0 70.7 79.9 77.9 95.4 68.6 89.5

24 58.7 61.7 69.2 100.0 65.0 36.9 71.2 90.4 65.0 67.5 

Table B.8.2.1.1-3: Parental mass balance. Recover of test item [% of AR] in soil after preliminary 

equilibrium test adsorption and extraction (3 hrs equilibrium time, soil/solution ration 1/10 (m/v), test 

concentration 1.08 mg L-1, containing 50 mg L-1 mercuric(II)chloride for sterilization). 

Compartment ‘Laacherhof 

AXXa’ 

‘Laacherhof 

AIII’ ‘Hoefchen’ ‘Molino’ ‘Saskatoon’ 

Solution 64.8 70.8 58.4 76.1 58.1 

ACN/water extract 1 23.9 16.4 27.4 15.6 21.5 

ACN/water extract 2 3.1 5.5 1.7 2.0 12.3 

Test item 

Recovery 91.8 92.7 87.5 93.7 91.9 

Unidentified in solution 1.3a 0.0 8.0a 0.0 0.0 

Unidentified in ACN/water extracts 0.0 0.0 0.0 0.0 0.0 

NER 1.7 2.8 1.8 0.5 2.5 

Total recovery 94.8 95.5 97.3 94.2 94.4 

a

 Mostly spirotetramat-enol 
– 121 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.2.1.1-4: Calculated non-linear (Freundlich) and linear adsorption isotherm parameter for spirotetramat. 

Non-linear isotherm (Freundlich) Linear isotherm 

Soil Texture pH (CaCl2) pH (sup.)a Corg [%] KF(ads) [L kg-1] KFOC(ads) [L kg-1] 1/n R2 Kd(ads) [L kg-1] KOC(ads) [L kg-1] R2

‘Laacherhof AXXa’ Loamy sand 6.1 6.6 2.38 4.79 201 1.001 0.980 4.38 184 0.988 ‘Laacherhof AIII’ Sandy loam 6.8 6.2 0.87 3.78 435 0.892 0.993 3.80 437 0.972 ‘Hoefchen’ Silt loam 5.9 6.9 2.33 4.10 176 0.945 0.994 4.69 201 0.997 ‘Molino’ Sandy loam 5.4 6.6 0.93 4.05 435 0.823 0.976 3.58 385 0.809 ‘Saskatoon’ Loam 4.7 6.3 2.33 3.70 159 1.042 0.903 5.52 237 0.914 a pH in the supernatant of the test solution. Table B.8.2.1.1-5: Calculated Freundlich desorption isotherm parameter for spirotetramat. 

1st desorption Serial desorption (only highest test concentration)b Soil Texture pH (CaCl2) pH (sup.)a Corg [%] KF(des)

[L kg-1] 

KFOC(des)

[L kg-1] 1/n R2 KFser [L kg-1] KFOCser [L kg-1] 1/n 

‘Laacherhof AXXa’ Loamy sand 6.1 6.6 2.38 40.7 1710 1.207 0.900 3.03 127 0.482 ‘Laacherhof AIII’ Sandy loam 6.8 6.2 0.87 22.8 2619 0.985 0.988 2.69 310 0.430 ‘Hoefchen’ Silt loam 5.9 6.9 2.33 14.2 610 0.952 0.986 3.19 137 0.504 ‘Molino’ Sandy loam 5.4 6.6 0.93 33.6 3616 0.949 0.997 2.44 263 0.388 ‘Saskatoon’ Loam 4.7 6.3 2.33 23.0 988 1.315 0.923 4.18 179 0.621 a pH in the supernatant of the test solution b Calculated by the reviewer 
– 122 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Conclusion:

The adsorption constants KF(ads) of spirotetramat calculated on the basis of the Freundlich isotherms for the 

five test soils ranged from 3.70 – 4.79 L kg-1. Respective calculated KFOC(ads) values were in the range of 159 

– 435 L kg-1, 1/n values were in a range of 0.89 – 1.04. Spirotetramat is classified as medium mobile

according to the classification scheme of McCall et al. (1981)1 and moderately mobile according to FAO2

classification. 

Reviewer comments:

• Linear adsorption constants (KOC(ads)) were close to the Freundlich adsorption constants with a range 

of 184 – 437 L kg-1. 

 

1

 McCall, J.P., D.A. Laskowsky, R.L. Swann, and H.J. Dishburger. 1981. Measurement of sorption coefficients of organic 

chemicals and their use in environmental fate analysis. Pages 89-109 In Test protocols for environmental fate & 

movement of toxicants. Proceedings of a symposium. Association of Official Analytical Chemists. 94th Annual Meeting, 

October 21-22, 1980. Washington, DC. 

2

 Food and Agriculture Organization of the United Nations. FAO PESTICIDE DISPOSAL SERIES 8. Assessing Soil 

Contamination: A Reference Manual. Appendix 2. Parameters of pesticides that influence processes in the soil. Editorial 

Group, FAO Information Division: Rome, 2000. 
– 123 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

B.8.2.1.2 Adsorption and desorption of relevant metabolites, degradation and reaction products 

(OECD Annex IIA, 7.4.2) 

The adsorption/desorption behaviour of the following metabolites of spirotetramat was investigated: 

• Spirotetramat-enol (batch equilibrium experiment, aged adsorption study) 

• Spirotetramat-ketohydroxy (batch equilibrium experiment) 

• Spirotetramat-MA-amide (batch equilibrium experiment) 

• Spirotetramat-enol dimer 1 and dimer 2 (HPLC method) 

Reference: Adsorption/desorption of BYI08330-cis-Enol in five different soils 

Author(s), year: Hein, W., 2005a 

Study/Report number: M-267858-01-2, IM2000 

Guideline(s): 95/36/EC (1995), OECD Guidelines 106 (2000), US-EPA N 163-1 (1982), 

Canadian PMRA DACO 8.2.4.2 (1987)1

GLP: Yes 

Deviations: None 

Validity: Study considered acceptable 

Material and methods:

Test substance: [Azaspirodecenyl-3-14C]-spirotetramat-enol, 4.54 MBq mg-1

, 

> 98 % radiochemical purity (HPLC), batch BECH 0917 and 1626 

Reference substance: Spirotetramat-enol (unlabelled), spirotetramat-ketohydroxy 

Soils: Air dried, 2-mm sieved 

Soil/solution ratio: 1/1, m/v 

Temperature: 20 ± 1 °C 

Test concentrations: No definitive test conducted, test concentrations used for preliminary test was 

1.0 mg L-1 in 0.01 M CaCl2 (either with or without 50 mg L-1 mercuric(II)chloride as 

biocide) 

Co-solvent: None 

Preliminary tests: Preliminary tests were conducted to ensure appropriate soil/solution ratio, 

appropriate equilibrium time, sorption to the test vessel and stability of the test 

item in the test solution 

Pre-equilibration time 16 hrs 

Equilibration time: No definitive test conducted owing to instability of test item in preliminary tests 

Sample processing: After phase separation, soil samples were extracted twice with 40 ml of 

acetonitrile/water (1/1, v/v, adjusted to approx. pH 9 with ammonium hydroxide, 

additional buffered by the addition of 1 g L-1 ammonium chloride). Extracts were 

combined, radio-assayed by LSC and analysed by HPLC. 

Analytical techniques: LSC, HPLC-UV/RAD 

Calculations: No definitive test conducted owing to instability of test item in preliminary tests 

 

1

 The Canadian guideline is improperly cited in the study report. It should be cited as: Agriculture Canada (1987) Trade 

Memorandum T-1-255, Guidelines for Determining Environmental Chemistry and Fate of Pesticides. 
– 124 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.2.1.2-1: Physico-chemical characteristics of test soils used for adsorption/desorption of 

spirotetramat-enol. 

Soil ‘Laacherhof 

AXXa’ 

‘Laacherhof 

AIII’ ‘Hoefchen’ ‘Molino’ ‘Saskatoon’ 

Batch ID 20020822 20020822 20040607 81704-S 980803 

Geographic 

location 

Monheim/ 

NorthrhineWestfalia/ 

Germany 

Monheim/ 

NorthrhineWestfalia/ 

Germany 

Burscheid/ 

NorthrhineWestfalia/ 

Germany 

Pensacola 

Florida/ 

USA 

Saskatchewan/

Canada 

Texture (USDA) Sandy loam Silt loam Silt loam Sandy loam Loam 

Sand (USDA) [%] 72.4 36.9 12.7 76 27.3 

Silt (USDA) [%] 22.6 51.1 72.5 16 48.3 

Clay (USDA) [%] 5.0 12.0 14.7 8 24.4 

pH (CaCl2) 6.3 7.6 6.1 6.2 4.7 

pH (water) 6.9 6.8 6.7 6.3 5.2 

pH (KCl) 6.4 nd 6.4 5.4 nd 

Organic carbon [%] 1.47 0.88 2.62 0.87 2.3 

CEC [meq kg-1] 103 98 160 50 199 

WHC (0.33 bar) [%] 29.1 20.7 31.3 7.4 nd 

MWHC [%] 34.4 36.4 72.7 23.0 nd 

Findings:

Spirotetramat-enol was found to be stable in the 0.01 M CaCl2 solution over a time period of 48 hrs, no 

adsorption to the test vessel was observed. 

From preliminary soil/solution ratio test (‘Hoefchen am Hohenseh 4a’ and ‘Molino’ soil), it was obvious that 

spirotetramat-enol was not stable after an adsorption phase of 24 hours, neither without nor with a biocide. 

Adsorption rate was in a range of 17.1 – 69.9 %, in the supernatant spirotetramat-enol accounted for 36.1 – 

90.5 % of total peak areas depending on the soil/solution ratio. Investigating the adsorption equilibrium at a 

soil ratio of 1/2 (m/v), no plateau concentration could be observed within 48 hrs. The rapid disappearance of 

the test item during the test can be mainly explained by transformation to spirotetramat-ketohydroxy (and 

other degradation products) and strong binding to the soil matrix. With parent mass balance below 90 % the 

quality criteria as set out in the current OECD guideline could not be met. 

Table B.8.2.1.2-2: Total recovery of radioactivity and spirotetramat-enol mass balance for preliminary

equilibrium tests on adsorption in the absence and presence of biocide. 

Total AR Spirotetramat-enol 

Soil Biocide DAT Supernatant Extract 

Soil 

residues 

(NER) 

Total Supernatant Extract Total 

0.25 70.7 6.7 20.4 97.8 67.2 5.6 72.8 

1 30.6 14.8 51.8 97.2 20.6 7.1 27.7 Without 

biocide 

2 21.1 14.8 60.6 96.4 8.1 5.9 14.0 

0.25 73.7 7.0 17.6 98.3 69.7 6.2 75.8 

1 48.7 13.8 35.4 97.8 37.5 8.8 46.3 

‘Hoefchen’ 

With 

biocide 

2 36.8 16.5 41.5 94.7 23.7 8.9 32.6 

0.25 82.0 9.4 7.5 98.8 79.6 8.9 88.5 

1 55.8 17.3 25.0 98.1 50.2 12.1 62.3 Without 

biocide 

2 31.3 20.8 46.1 98.1 20.7 9.7 30.4 

0.25 78.3 11.4 9.9 99.5 75.5 10.4 86.0 

1 57.4 18.8 20.5 96.7 50.0 12.2 62.2 

‘Molino’ 

With 

biocide 

2 45.5 22.9 29.6 97.9 35.0 12.3 47.2 
– 125 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Conclusion:

No definitive test data regarding the adsorption/desorption characteristics of spirotetramat-enol could be 

derived within this study. The rapid disappearance of spirotetramat-enol during preliminary test can be 

mainly attributed to transformation to spirotetramat-ketohydroxy (and other degradation products) and strong 

binding to the soil matrix. With parent mass balance below 90 % the quality criteria as set out in the current 

OECD guideline could not be met. 

Reviewer comments:

None 

Reference: [Azaspirodecenyl-3-14C]BYI08330-enol: Time-dependent sorption in soils 

Author(s), year: Menke, U., 2006b 

Study/report number: M131 1375-1, MEF-05/222 

Guideline(s): Supportive non-guideline study, based on parts of OECD Guideline 106 (2001) 

and US-EPA N 163-1 (1982) 

GLP: Yes 

Deviations: Supportive non-guideline study - not applicable 

Validity: Study considered as additional information, only – study not essential 

Material and methods:

Test substance: [Azaspirodecenyl-3-14C]-spirotetramat-enol, 4.54 MBq mg-1, 

96.8 % radiochemical purity (HPLC), batch BECH 1539

Reference substances: Spirotetramat-enol (unlabelled), spirotetramat, spirotetramat-ketohydroxy, 

spirotetramat-MA-amide 

Application: 20 g d.w. soil (air dried, approx. 25 – 30 % of MWHC) were fortified with 

spirotetramat-enol (in 1.2 mL of 0.01 M NaHCO3 solution) at a spike level of 310 

μg kg-1 (brought to a MWHC of 50 % with distilled water). 

Co-solvent: 0.22 % of methanol in application solution 

Aging: After application of the test item the spiked samples were incubated for 0, 1, 5 and 

24 hrs at 20 ± 1 °C in the dark at 50 % of MWHC. 

Desorption: After aging, spiked soil samples were overlaid with 20 ml of 0.01 M CaCl2 solution 

resulting in a soil to solution ratio of 1/1 (m/v) and shaken for 0.03, 1.03, 3, 5 and 

24 hrs. After phase separation, supernatants were radio-assayed by LSC and 

analysed by HPLC. 

Extraction procedure: After each desorption period, soil samples were extracted three times with 

acetonitrile/water/ammonia/ammonium chloride (500/500/2.5/1.0, v/v/v/w), 

extracts were combined and radio-assayed by LSC. Soil residues were 

additionally extracted with the same solvent using a microwave at 70 °C and the 

extract radio-assayed by LSC. Both extract were further analysed by HPLC. Non 

extractable residues (NER) were analysed by combustion-LSC. 

Analytical techniques: LSC, HPLC-UV/RAD, LC-MS/MS 

LOQ ≤ 0.4 % of AR 

Calculations: Amounts of ‘test item adsorbed to the soil’ (Cextr.) are calculated from the sum of 

residue amounts in the organic and aggressive extracts. 
– 126 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.2.1.2-3: Soils used for adsorption/desorption of spirotetramat. 

Soil ‘Hoefchen’ ‘Molino’ 

Batch ID 20040607 20040427 

Geographic location Burscheid/Northrhine Westfalia/ 

Germany 

Pensacola/Florida/ 

USA 

Texture (USDA) Silt loam Sandy loam 

Sand (USDA) [%] 15.6 77.3 

Silt (USDA) [%] 68.1 12.7 

Clay (USDA) [%] 16.2 10.0 

pH (CaCl2) 6.1 5.4 

pH (water) 6.7 6.0 

pH (KCl) 6.4 5.4 

Organic carbon [%] 2.62 0.8 

CEC [meq kg-1] 160 42 

MWHC [%] 67.8 26.3 

Findings:

The test item was stable in 0.01 M CaCl2 solution over a period of 24 hrs (93.5 % of test item recovered), no 

indications for adsorption to the surface of the test vessels was observed. 

The total recovery of radioactivity was in a range of 91.1 – 98.9 % of AR for ‘Hoefchen’ soil and 96.0 – 99.0 

% of AR for ‘Molino’ soil. Formation of NER was a strong time-depending process even in samples without 

aging period and was increasing with increasing time of desorption. In non-aged samples of ‘Hoefchen’ soil 

NER increased from 19.8 to 53.7 % of AR from 0.03 to 24 hrs of desorption phase, in of ‘Molino’ soil a similar 

increase was observed (13.7 to 49.6 % of AR). 

The instability of spirotetramat-enol in the test system once in contact with soil was pronounced, after an 

aging period of 24 hrs and a desorption phase of 24 hrs only 17.5 and 18.6 % of AR could be recovered in 

the extracts of ‘Hoefchen’ and ‘Molino’ soil, respectively. The amount of total radioactivity desorbed by the 

aqueous CaCl2 solution rapidly decreased with time of aging from 52.0 to 5.4 % of AR and 55.1 to 4.8 % of 

AR in ‘Hoefchen’ and ‘Molino’ soil (each after 0.03 hrs of desorption). Correspondingly the amount of 

radioactivity in the organic extracts (sum of ambient and aggressive extract) increased reaching a ‘saturation 

level’ of about 40 – 45 % of AR for ‘Hoefchen’ soil already after 1 hr of aging and about 48 – 50 % of AR for 

‘Molino’ soil at the 5 hrs time point. An extremely fast adsorption process became evident when considering 

the amount of spirotetramat-enol desorbed by the aqueous solution (mobile fraction of spirotetramat-enol). 

Already within the time period of 0.03 hrs necessary for handling about half of the applied amount of test item 

was adsorbed to soil and thus only 49.0 and 52.1 % of AR (‘Hoefchen’ and ‘Molino’ soil) were left in the 

desorption phase. No spirotetramat-enol was desorbable with 0.01 M CaCl2 after 5 hrs of aging in both soils. 

Due to the very rapid degradation/dissipation of spirotetramat-enol in the desorption phase in presence of 

soil no stable equilibrium was measurable. Therefore it was in fact not possible to derive a Kd or a KOC using 

the Freundlich adsorption isotherm. However, using extracted amounts of spirotetramat-enol in soil as 

adsorbed part and in the limit of detection as the concentration of test item desorbed, the KOC resulted in 

values of about 1200 L kg-1 for ‘Hoefchen’ soil and about 4000 L kg-1 for ‘Molino’ soil. 
– 127 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.2.1.2-4: Material balance of radioactivity [% of AR] in dependence of aging and desorption 

period (mean value). 

Extractable 

Soil 

Aging 

period 

[hrs] 

Desorption 

period 

[hrs] 

CaCl2

solution 

Organic 

extract 

Aggressive 

extract Total 

NER Total 

recovery 

0.03 52.0 20.6 6.4 79.1 19.8 98.9 

1.03 7.9 22.0 16.9 46.8 45.7 92.4 

3 5.4 22.0 16.9 44.2 46.8 91.1 

5 5.2 19.5 16.7 41.4 52.2 93.6 

0 

24 5.4 19.9 17.3 42.6 53.7 96.4 

0.03 16.1 31.3 8.8 56.2 37.6 93.9 1 

24 5.2 30.1 14.7 50.0 44.1 94.1 

0.03 6.0 31.4 9.2 46.6 46.5 93.1 5 

24 5.4 30.2 13.0 48.6 44.4 93.0 

0.03 5.0 29.6 12.0 46.6 46.9 93.5 

‘Hoefchen’ 

24 

24 5.0 30.0 10.7 45.7 49.4 95.1 

0.03 55.1 21.3 6.1 82.5 13.7 96.2 

1.03 21.8 29.5 14.5 65.7 32.1 97.8 

3 8.0 29.0 17.9 54.9 44.1 99.0 

5 6.5 29.9 14.6 51.1 47.8 98.9 

0 

24 4.8 29.6 14.6 49.0 49.6 98.6 

0.03 21.9 36.0 9.7 67.6 29.1 96.8 1 

24 5.2 35.0 13.2 53.3 45.6 98.9 

0.03 8.0 36.4 11.8 56.2 42.0 98.2 5 

24 5.2 36.8 12.7 54.7 43.5 98.2 

0.03 4.9 36.0 10.9 51.8 44.2 96.0 

‘Molino’ 

24 

24 5.0 34.7 12.5 52.2 43.9 96.1 

Table B.8.2.1.2-5: Characterization of the CaCl2 solution and extractable radioactivity [% of AR] in 

dependence of the aging and desorption period (mean value). 

Spirotetramat-enol Degradates 

Soil 

Aging 

period 

[hrs] 

Desorption 

period 

[hrs] 

CaCl2

solution 

Both 

organic 

extracts 

Total CaCl2

solution 

Both 

organic 

extracts 

Total 

0.03 49.0 14.7 63.7 3.1 12.4 15.5 

1.03 2.6 21.2 23.8 5.3 17.7 23.0 

3 < LOQ 20.0 20.0 5.4 18.9 24.3 

5 < LOQ 18.7 18.7 5.2 17.4 22.6 

0 

24 < LOQ 18.9 18.9 5.4 18.3 23.7 

0.03 11.4 19.3 30.7 4.7 20.8 25.5 1 

24 < LOQ 19.3 19.3 5.2 25.5 30.7 

0.03 < LOQ 18.6 18.6 6.0 22.0 28.0 5 

24 < LOQ 21.4 21.4 5.4 21.7 27.1 

0.03 < LOQ 21.7 21.7 5.0 19.9 24.9 

‘Hoefchen’ 

24 

24 < LOQ 17.5 17.5 5.0 23.2 28.2 

0.03 52.1 19.3 71.4 3.0 8.1 11.1 

1.03 16.8 27.2 44.0 5.0 16.8 21.8 

3 < LOQ 27.2 27.2 8.0 19.7 27.7 

5 < LOQ 23.5 23.5 6.5 21.1 27.6 

0 

24 < LOQ 18.7 18.7 4.8 25.5 30.3 

0.03 17.9 25.4 43.3 4.0 20.3 24.3 1 

24 < LOQ 25.4 25.4 5.2 22.7 27.9 

0.03 < LOQ 18.0 18.0 8.0 30.2 38.2 

‘Molino’ 

5 

24 < LOQ 19.9 19.9 5.2 29.5 34.7 
– 128 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Spirotetramat-enol Degradates 

Soil 

Aging 

period 

[hrs] 

Desorption 

period 

[hrs] 

CaCl2

solution 

Both 

organic 

extracts 

Total CaCl2

solution 

Both 

organic 

extracts 

Total 

0.03 < LOQ 15.9 15.9 4.9 30.9 35.8 24 

24 < LOQ 18.6 18.6 5.0 28.6 33.6 

Table B.8.2.1.2-6: Calculation of desorbed and adsorbed concentration and of Kd and KOC values of 

spirotetramat-enol in dependence of aging and desorption period. 

Soil 

Aging 

period 

[hrs] 

Desorption 

period 

[hrs] 

Cdes

[μg mL-1] 

Cextr.

[μg g-1] 

Kd

[L kg-1] 

KOC

[L kg-1] 

0.03 0.27 -0.068a

 -0.25 -9.7 

1.03 0.02 0.061 4.4 169 

3 0.002 0.062 32.1 1225 

5 0.002 0.058 30.1 1149 

0 

24 0.002 0.059 30.4 1161 

0.03 0.61 0.035 0.6 22 1 

24 0.002 0.070 26.9 1386 

0.03 0.002 0.058 29.9 1142 5 

24 0.002 0.067 34.5 1317 

0.03 0.002 0.067 34.9 1332 

‘Hoefchen’ 

24 

24 0.002 0.054 28.0 1069 

0.03 0.25 -0.047a

 -0.18 -23.1 

1.03 0.08 0.051 0.6 79 

3 0.011 0.080 7.5 940 

5 0.002 0.072 37.3 4659 

0 

24 0.002 0.058 29.7 3712 

0.03 0.097 0.039 0.4 50 1 

24 0.002 0.063 32.5 4068 

0.03 0.006 0.054 17.7 2208 5 

24 0.002 0.061 31.6 3952 

0.03 0.002 0.048 16.3 2039 

‘Molino’ 

24 

24 0.002 0.057 29.5 3687 

a

 Theoretically this value should be zero 

Conclusion:

Sorption and binding of spirotetramat-enol to soil was extremely fast and increased rapidly with aging time in 

soil. The portion not tightly bound to the soil, i.e. the portion that is releasable by aqueous solution from soil 

(mobile fraction), is degraded within a few hours (mainly to spirotetramat-ketohydroxy). From these results it 

can be concluded that spirotetramat-enol is absent from the soil pore water (either degraded or tightly bound 

to soil) within a very short period of time. 

Reviewer comments:

• Results of this study are considered as additional information, only. Study not considered 

essential.
– 129 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Reference: 14C-BYI08330-ketohydroxy: Adsorption/desorption in five soils 

Author(s), year: Hein, W., 2005b 

Study/Report number: M-267955-02-2, IM2001, amended 30.08.2006 

Guideline(s): 95/36/EC (1995), OECD Guidelines 106 (2000), US-EPA N 163-1 (1982), 

Canadian PMRA DACO 8.2.4.2 (1987)1

GLP: Yes 

Deviations: None 

Validity: Study considered acceptable 

Material and methods:

Test substance: [Azaspirodecenyl-3-14C]-spirotetramat-ketohydroxy, 4.31 MBq mg-1

, 

> 98 % radiochemical purity (HPLC), batch BECH 1588 and 1619 

Reference substance: Spirotetramat-ketohydroxy (unlabelled) 

Soils: Air dried, 2-mm sieved 

Soil/solution ratio: 1/1, m/v (‘Laacherhof AXXa’, ‘Laacherhof AIII’) 

1/2, m/v (‚Hoefchen’, ‚Molino’, ‚Saskatoon’) 

Temperature: 20 ± 1 °C 

Test concentrations: 0.01, 0.03, 0.1, 0.3 and 1.0 mg L-1

in 0.01 M CaCl2 (containing 50 mg L-1 mercuric(II)chloride as biocide) 

Co-solvent: None 

Pre-equilibration time 16 hrs 

Equilibration time: 24 hrs for adsorption, 24 hrs for desorption (highest test concentration: 3 

desorption cycles) 

Extraction: After desorption remaining soil was extracted two times with 20 ml acetonitrile 

followed by three times with acetonitrile/water (1/1, v/v) + 0.5 % formic acid (pH 

2.5). After extraction the soil residues were radio-assayed by combustion-LSC. 

Analytical techniques: LSC, HPLC-UV/RAD, HPLC-MS/MS(ESI) 

Calculations: The amount adsorbed was calculated by subtracting the equilibrium concentration 

in the solution from the initial concentration applied. 

The Freundlich adsorption isotherm is described as Cs = KF(ads) × Cw

(1/n), whereby 

Cs is the equilibrium concentration of the test item in the soil after adsorption [μg g1

], Cw the equilibrium concentration in the solution [μg mL-1], KF(ads) is the 

Freundlich adsorption coefficient and 1/n is the Freundlich exponent. KF(ads) and 

1/n were obtained by plotting log(Cs) vs. log(Cw) to give 1/n as the slope and 

log(KF(ads)) as the intercept of the linear regression. Desorption (based on the 

desorption constant KF(des)) was calculated in a similar way. 

In addition, the linear adsorption coefficient Kd(ads) was obtained by linear 

regression plotting CW vs. CS without data transformation (calculated by the 

reviewer). 

Based on the organic carbon [%], the Freundlich adsorption coefficient is 

expressed as KFOC(ads) = (KF(ads) × 100) / Corg (Freundlich desorption and linear 

adsorption/desorption coefficients are expressed in a similar way). 

 

1

 The Canadian guideline is improperly cited in the study report. It should be cited as: Agriculture Canada (1987) Trade 

Memorandum T-1-255, Guidelines for Determining Environmental Chemistry and Fate of Pesticides. 
– 130 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.2.1.2-7: Physico-chemical characteristics of test soils used for adsorption/desorption of 

spirotetramat-ketohydroxy. 

Soil ‘Laacherhof 

AXXa’ 

‘Laacherhof 

AIII’ ‘Hoefchen’ ‘Molino’ ‘Saskatoon’ 

Batch ID 20040607 20040607 20040607 81704-S 81004-S 

Geographic 

location 

Monheim/ 

NorthrhineWestfalia/ 

Germany 

Monheim/ 

NorthrhineWestfalia/ 

Germany 

Burscheid/ 

NorthrhineWestfalia/ 

Germany 

Pensacola 

Florida/ 

USA 

Saskatchewan/

Canada 

Texture (USDA) Sandy loam Silt loam Silt loam Sandy loam Clay loam 

Sand (USDA) [%] 72.7 42.0 12.7 76 28 

Silt (USDA) [%] 18.4 44.8 72.5 16 44 

Clay (USDA) [%] 8.9 13.2 14.7 8 28 

pH (CaCl2) 6.0 6.4 6.1 6.2 5.5 

pH (water) 6.6 6.9 6.7 6.3 5.6 

pH (KCl) 6.3 6.7 6.4 5.4 4.8 

Organic carbon [%] 1.30 1.10 2.62 0.87 2.44 

Carbonate [%] < 0.1 < 0.1 < 0.1 0.3 0.7 

CEC [meq kg-1] 64 96 160 50 196 

WHC (0.33 bar) [%] 19.5 23.9 31.3 7.4 23.9 

MWHC [%] 38.3 43.5 72.7 23.0 44.5 

Findings:

In the pre-test, it was obvious that spirotetramat-ketohydroxy was not stable in the presence of soil. Hence, 

to prevent microbial degradation of the test item the test soils were sterilized by soil equilibration in 0.01 M 

CaCl2 containing 50 mg L-1 mercuric(II)chloride for two days. Under sterile conditions (preliminary parental 

mass balance test), spirotetramat-ketohydroxy was stable for 24 hrs of adsorption equilibrium time in 3 soils 

(test item recovery: 90.7 – 93.7 % of AR). In the ‘Laacherhof AXXa’ and ‘Laacherhof AIII’ total recovery of the 

test item was slightly below 90 % of AR (88.6 % and 87.6 % of AR, respectively). The test item did not

adsorb to the wall surface of the test vessel. 

The overall material balance for all concentrations for individual samples was in the range of 92.5 – 98.6 % 

of AR. After 24 hrs of equilibration 29.8 – 63.0 % of AR was adsorbed to the test soils. The calculated 

adsorption constants KF(ads) of the Freundlich isotherms for the five test soils ranged from 0.516 – 2.21 L kg-1

(R2≥ 0.999), the Freundlich exponent 1/n was in a range of 0.915 – 0.929. The desorption KF(des) values 

were 1.3 – 1.7 times higher than those obtained for adsorption. 

Table B.8.2.1.2-8: Determination of soil/solution ratio: Adsorption of the test item [%] after 24 hrs 

shaking period at different soil/solution ratios (test concentration 0.97 mg L-1, mean of replicates). 

Soil/solution 

ratio (m/v) 

‘Laacherhof 

AXXa’ 

‘Laacherhof 

AIII’ ‘Hoefchen’ ‘Molino’ ‘Saskatoon’ 

1/1 43.2 39.0 57.7 59.6 75.1 

1/2 29.7 25.9 42.6 39.7 58.6 
– 131 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.2.1.2-9: Determination of the adsorption equilibrium time: Adsorption of the test item 

(expressed as test item equiv. in the adsorption solution, [mg parent equiv. L-1]) after a shaking 

period of 2 – 96 hrs (soil/solution ration 1/1 (m/v) for ‘Hoefchen’, ‘Molino’ and ‘Saskatoon’ soil and 1/2 

(m/v) for ‘Laacherhof AXXa’ and ‘Laacherhof AIII’ soil, test concentration 0.98 mg L-1, preequilibration time approx. 16 hrs, containing 50 mg L-1 mercuric(II)chloride as biocide). 

HAT ‘Laacherhof 

AXXa’ 

‘Laacherhof 

AIII’ ‘Hoefchen’ ‘Molino’ ‘Saskatoon’ 

2 0.65 0.65 0.63 0.72 0.52 

4 0.63 0.64 0.62 0.69 0.50 

6 0.63 0.64 0.62 0.68 0.48 

24 0.59 (0.54)a

 0.60 (0.56) 0.59 (0.54) 0.63 (0.59) 0.44 (0.42) 

30 0.59 0.61 0.58 0.64 0.42 

48 0.58 (0.54) 0.60 (0.55) 0.58 (0.53) 0.60 (0.56) 0.41 (0.39) 

72 0.56 (0.52) 0.59 (0.54) 0.57 (0.53) 0.59 (0.55) 0.40 (0.37) 

96 0.57 (0.53) 0.59 (0.54) 0.57 (0.53) 0.59 (0.56) 0.38 (0.34) 

a

 Number in parentheses give test item concentration [mg parent L-1] 

Table B.8.2.1.2-10: Determination of the desorption equilibrium time: Desorption of the test item 

(expressed as test item equiv. in the adsorption solution, [mg parent equiv. L-1]) after a shaking 

period of 2 – 72 hrs (soil/solution ration 1/1 (m/v) for ‘Hoefchen’, ‘Molino’ and ‘Saskatoon’ soil and 1/2 

(m/v) for ‘Laacherhof AXXa’ and ‘Laacherhof AIII’ soil, test concentration 0.93 mg L-1, preequilibration time approx. 16 hrs, adsorption time 24 hrs, containing 50 mg L-1 mercuric(II)chloride as 

biocide). 

HAT ‘Laacherhof 

AXXa’ 

‘Laacherhof 

AIII’ ‘Hoefchen’ ‘Molino’ ‘Saskatoon’ 

2 0.29 0.28 0.27 0.19 0.21 

4 0.29 0.28 0.27 0.20 0.22 

6 0.29 0.30 0.22 0.25 0.22 

24 0.30 0.30 0.28 0.20 0.22 

48 0.29 0.30 0.27 0.21 0.22 

72 0.28 0.29 0.27 0.20 0.21 

Table B.8.2.1.2-11: Parental mass balance: Recover of test item [% of AR] in soil after the preliminary 

adsorption equilibrium test and extraction (24 hrs equilibrium time, soil/solution ration 1/1 (m/v) for 

‘Hoefchen’, ‘Molino’ and ‘Saskatoon’ soil and 1/2 (m/v) for ‘Laacherhof AXXa’ and ‘Laacherhof AIII’ 

soil, test concentration 0.98 mg L-1, pre-equilibration time approx. 16 hrs, containing 50 mg L-1

mercuric(II)chloride as biocide). 

Compartment ‘Laacherhof 

AXXa’ 

‘Laacherhof 

AIII’ ‘Hoefchen’ ‘Molino’ ‘Saskatoon’ 

Solution 37.6 37.1 42.2 51.0 33.9 

Extraction 1 45.9 44.2 44.5 36.5 53.4 

Extraction 2 5.1 6.3 4.0 3.6 6.3 

Test item 

Recovery 88.6 87.6 90.7 91.2 93.7 

Unidentified RA in solution 3.5 3.1 3.6 3.2 1.6 

Unidentified RA in extracts 0.0 0.2 0.0 0.0 0.0 

NER 1.1 1.6 1.1 0.9 1.7 

Total recovery 93.2 92.5 95.3 95.2 96.9 
– 132 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.2.1.2-12: Calculated non-linear (Freundlich) and linear adsorption isotherm parameter for spirotetramat-ketohydroxy. 

Non-linear isotherm (Freundlich) Linear isotherm 

Soil Texture pH (CaCl2) pH (sup.)a Corg [%] KF(ads)

[L kg-1] 

KFOC(ads)

[L kg-1] 1/n R2 Kd(ads) [L kg-1] KOC(ads) [L kg-1] R2

‘Laacherhof AXXa’ Sandy loam 6.0 6.7 1.30 0.533 41.0 0.920 1.000 0.560 43.1 0.998 ‘Laacherhof AIII’ Silt loam 6.4 6.9 1.10 0.516 46.9 0.929 1.000 0.529 48.1 0.997 ‘Hoefchen’ Silt loam 6.1 6.6 2.62 1.08 41.2 0.927 1.000 1.10 42.0 0.996 ‘Molino’ Sandy loam 6.2 6.7 0.87 0.862 99.1 0.918 1.000 0.867 99.7 0.994 ‘Saskatoon’ Clay loam 5.5 6.0 2.44 2.21 90.4 0.915 1.000 2.28 93.4 0.994 a pH in the supernatant of the test solution. Table B.8.2.1.2-13: Calculated non-linear (Freundlich) desorption isotherm constants for spirotetramat-ketohydroxy. 

1st Desorption Serial desorption (only highest test concentration) Soil Texture pH (CaCl2) pH (sup.)a Corg [%] KF(des)

[L kg-1] 

KFOC(des)

[L kg-1] 1/n R2 KFser [L kg-1] KFOCser [L kg-1] 1/n R2

‘Laacherhof AXXa’ Sandy loam 6.0 6.7 1.30 0.668 51.4 0.933 1.000 0.442 34.0 0.566 0.999 ‘Laacherhof AIII’ Silt loam 6.4 6.9 1.10 0.713 64.8 0.954 0.999 0.415 37.7 0.522 1.000 ‘Hoefchen’ Silt loam 6.1 6.6 2.62 1.60 61.2 0.983 1.000 0.922 35.2 0.581 0.992 ‘Molino’ Sandy loam 6.2 6.7 0.87 1.47 170 0.885 0.999 0.636 73.1 0.312 0.998 ‘Saskatoon’ Clay loam 5.5 6.0 2.44 2.84 116 0.902 0.997 1.51 61.7 0.509 0.999 a pH in the supernatant of the test solution. 
– 133 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Conclusion:

The adsorption constants KF(ads) of spirotetramat-ketohydroxy calculated based on the Freundlich isotherms 

for the five test soils ranged from 0.516 – 2.21 L kg-1. The respective calculated KFOC(ads) values were in the 

range of 41.0 – 99.1 L kg-1, 1/n values were in a range of 0.915 – 0.929. Spirotetramat-ketohydroxy is 

classified as highly mobile according to the classification scheme of McCall et al. (1981)1 and mobile

according to FAO2

 classification. 

Reviewer comments:

• Linear adsorption constants (KOC(ads)) were close to the Freundlich adsorption constants with a range 

of 42.0 – 99.7 L kg-1. 

Reference: [

14C]-BYI08330-MA-amide: Adsorption to and desorption from five soils 

Author(s), year: Simmonds, M., Early, E., 2005 

Study/Report number: M-263686-01-2, CX/04/070 

Guideline(s): OECD Guidelines 106 (2000), US-EPA N 163-1 (1982), Canadian PMRA DACO 

8.2.4.2 (1987)3, Japanese MAFF new Test Guidelines for Supporting Registration 

of Pesticides (2000 and 2001) 

GLP: Yes 

Deviations: None 

Validity: Study considered acceptable 

Material and methods:

Test substance: [14C]-spirotetramat-MA-amide (see structure for labelling, which is indicated by an 

asterisk), 4.08 MBq mg-1, > 98 % radiochemical purity (HPLC), batch BECH 1621 

Reference substance: Spirotetramat-MA-amide (unlabelled) 

Soils: Air dried, 2-mm sieved 

Soil/solution ratio: 1/1, m/v 

Temperature: 24 ± 2 °C (adsorption), 20 ± 2 °C (desorption) 

Test concentrations: 0.005, 0.01, 0.05, 0.1 and 0.5 mg L-1

in 0.01 M CaCl2

Co-solvent: Acetonitrile (≤ 0.4 %, v/v) 

Pre-equilibration time 16 hrs 

Equilibration time: 24 hrs for adsorption, 2 hrs for desorption (highest test concentration: 3 desorption 

cycles) 

Extraction: After desorption remaining soil was extracted twice with 40 ml of acetonitrile/water 

(80/20, v/v, adjusted to pH 4 with formic acid) followed by one extraction with 40 

 

1

 McCall, J.P., D.A. Laskowsky, R.L. Swann, and H.J. Dishburger. 1981. Measurement of sorption coefficients of organic 

chemicals and their use in environmental fate analysis. Pages 89-109 In Test protocols for environmental fate & 

movement of toxicants. Proceedings of a symposium. Association of Official Analytical Chemists. 94th Annual Meeting, 

October 21-22, 1980. Washington, DC. 

2

 Food and Agriculture Organization of the United Nations. FAO PESTICIDE DISPOSAL SERIES 8. Assessing Soil 

Contamination: A Reference Manual. Appendix 2. Parameters of pesticides that influence processes in the soil. Editorial 

Group, FAO Information Division: Rome, 2000. 

3

 The Canadian guideline is improperly cited in the study report. It should be cited as: Agriculture Canada (1987) Trade 

Memorandum T-1-255, Guidelines for Determining Environmental Chemistry and Fate of Pesticides. 
– 134 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

ml of acetonitrile. After extraction the soil residues were radio-assayed by 

combustion-LSC. 

Analytical techniques: LSC, HPLC-UV/RAD, LC-MS/MS 

LOQ = 0.004 % of AR 

Calculations: The amount adsorbed was calculated by subtracting the equilibrium concentration 

in the solution from the initial concentration applied. 

The Freundlich adsorption isotherm is described as Cs = KF(ads) × Cw

(1/n), whereby 

Cs is the equilibrium concentration of the test item in the soil after adsorption 

[μg g-1], Cw the equilibrium concentration in the solution [μg mL-1], KF(ads) is the 

Freundlich adsorption coefficient and 1/n is the Freundlich exponent. KF(ads) and 

1/n were obtained by plotting log(Cs) vs. log(Cw) to give 1/n as the slope and 

log(KF(ads)) as the intercept of the linear regression. Desorption (based on the 

desorption constant KF(des)) was calculated in a similar way. 

In addition, the linear adsorption coefficient Kd(ads) was obtained by linear 

regression plotting CW vs. CS without data transformation (calculated by the 

reviewer). 

Based on the organic carbon [%], the Freundlich adsorption coefficient is 

expressed as KFOC(ads) = (KF(ads) × 100) / Corg (Freundlich desorption and linear 

adsorption/desorption coefficients are expressed in a similar way). 

Table B.8.2.1.2-14: Physico-chemical characteristics of test soils used for adsorption/desorption of 

spirotetramat-MA-amide. 

Soil ‘Laacherhof 

AXXa’ 

‘Laacherhof 

AIIIa’ ‘Hoefchen’ ‘Molino’ ‘Saskatoon’ 

Batch ID 04/73 04/72 04/71 04/67 04/68 

Geographic 

location 

Monheim/ 

NorthrhineWestfalia/ 

Germany 

Monheim/ 

NorthrhineWestfalia/ 

Germany 

Burscheid/ 

NorthrhineWestfalia/ 

Germany 

Pensacola 

Florida/ 

USA 

Saskatchewan/

Canada 

Texture (USDA) Sandy loam Silt loam Silt loam Loamy sand Loam 

Soil taxonomic 

classification 

(USDA) 

Sandy, mixed, 

mesic Typic 

Cambudoll 

Loamy, mixed, 

mesic Typic 

Argudalfs 

Loamy, mixed, 

mesic Typic 

Argudalfs 

Ultisol na 

Sand (USDA) [%] 72.7 45.0 12.7 78 30 

Silt (USDA) [%] 18.4 40.1 72.5 15 45 

Clay (USDA) [%] 8.9 14.9 14.7 7 25 

pH (CaCl2) 6.3 6.7 6.5 5.7 5.4 

pH (water) 6.9 7.5 7.1 6.1 5.7 

pH (KCl) 6.3 6.7 6.3 Nd nd 

Organic carbon [%] 1.70 0.91 2.07 0.7 2.3 

CEC [meq kg-1] 89 87 141 47 212 

WHC (0.33 bar) [%] 19.5 23.9 31.3 9.0 24.7 

MWHC [%] 42.3 38.7 66.2 nd nd 

Findings:

No significant breakdown of spirotetramat-MA-amide in any soil was observed (> 90 % as test-item). 

The overall material balance for all concentrations for individual samples was in the range of 90.5 – 100.9 % 

of AR. After 24 hrs of equilibration 4.7 – 21.6 % of AR was adsorbed to the test soils. The calculated

adsorption constants KF(ads) of the Freundlich isotherms for the five test soils ranged from 0.06 – 0.18 L kg-1

(R2

≥ 0.998), the Freundlich exponent 1/n was in a range of 0.80 – 1.07. The desorption KF(des) values were 

1.6 – 2.3 times higher than those obtained for adsorption. 
– 135 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.2.1.2-15: Determination of the soil/solution ratio: Adsorption of the test item [%] after 24 hrs 

shaking period at different soil/solution ratios (test concentration 0.50 mg L-1). 

Soil/solution 

ratio (m/v) 

‘Laacherhof 

AXXa’ 

‘Laacherhof 

AIII’ ‘Hoefchen’ ‘Molino’ ‘Saskatoon’ 

1/1 4.8 4.4 9.2 14.4 10.7 

1/2 3.0 5.7 6.0 9.5 6.0 

1/3 1.8 6.8 3.4 7.0 4.9 

Table B.8.2.1.2-16: Determination of the adsorption equilibrium time: Adsorption of the test item [%] 

after a shaking period of 24 – 144 hrs (soil/solution ration 1/1 (m/v), test concentration 0.50 mg L-1, 

pre-equilibration time approx. 16 hrs). 

HAT ‘Laacherhof 

AXXa’ 

‘Laacherhof 

AIII’ ‘Hoefchen’ ‘Molino’ ‘Saskatoon’ 

24 6.7 6.2 11.2 14.3 8.2 

48 6.2 6.9 8.7 14.8 10.0 

72 7.1 8.1 8.8 17.4 13.9 

96 7.8 7.4 8.7 20.0 16.5 

120 8.5 6.8 8.5 21.0 17.1 

144 7.3 7.8 9.4 22.4 16.6 

Table B.8.2.1.2-17: Determination of the desorption equilibrium time: Desorption [%] of the test item 

after a shaking period of 1 – 48 hrs (soil/solution ration 1/1 (m/v), test concentration 0.50 mg L-1, preequilibration time approx. 16 hrs, adsorption time 48 hrs). 

HAT ‘Laacherhof 

AXXa’ 

‘Laacherhof 

AIII’ ‘Hoefchen’ ‘Molino’ ‘Saskatoon’ 

1 31.2 29.4 28.2 28.6 28.6 

2 32.0 30.6 32.2 29.5 36.1 

24 31.2 29.3 32.2 29.7 28.5 

48 30.7 29.9 33.1 29.5 34.9 
– 136 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.2.1.2-18: Calculated non-linear (Freundlich) and linear adsorption isotherm parameter for spirotetramat-MA-amide. 

Non-linear isotherm (Freundlich) Linear isotherm 

Soil Texture pH (CaCl2) pH (sup.)a Corg [%] KF(ads)

[L kg-1] 

KFOC(ads)

[L kg-1] 1/n R2 Kd(ads) [L kg-1] KOC(ads) [L kg-1] R2

‘Laacherhof AXXa’ Sandy loam 6.3 nd 1.7 0.075 4.4 1.07 1.000 0.071 4.2 0.997 ‘Laacherhof AIII’ Silt loam 6.7 nd 0.91 0.059 6.5 0.96 0.999 0.064 7.0 0.998 ‘Hoefchen’ Silt loam 6.5 nd 2.07 0.104 5.0 0.80 0.998 0.116 5.6 0.976 ‘Molino’ Loamy sand 5.7 nd 0.7 0.179 25.5 0.98 0.999 0.179 25.6 0.997 ‘Saskatoon’ Loam 5.4 nd 2.3 0.117 5.1 0.93 0.999 0.126 5.5 0.994 a pH in the supernatant of the test solution. Table B.8.2.1.2-19: Calculated desorption isotherm parameter for spirotetramat-MA-amide. 

1st Desorption Serial desorption (only highest test concentration)b Soil Texture pH (CaCl2) pH (sup.)a Corg [%] KF(des)

[L kg-1] 

KFOC(des)

[L kg-1] 1/n R2 KFser [L kg-1] KFOCser [L kg-1] 1/n 

‘Laacherhof AXXa’ Sandy loam 6.3 nd 1.7 0.13 7.8 0.99 0.994 0.04 2.4 0.229 ‘Laacherhof AIIIa’ Silt loam 6.7 nd 0.91 0.14 14.9 0.96 0.994 0.04 4.4 0.183 ‘Hoefchen’ Silt loam 6.5 nd 2.07 0.19 9.0 0.80 1.000 0.06 2.9 0.165 ‘Molino’ Loamy sand 5.7 nd 0.7 0.37 52.6 0.98 0.998 0.10 14.3 0.255 ‘Saskatoon’ Loam 5.4 nd 2.3 0.22 9.7 0.91 0.999 0.07 3.0 0.180 a pH in the supernatant of the test solution b Calculated by the reviewer 
– 137 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Conclusion:

The adsorption constants KF(ads) of spirotetramat-MA-amide calculated based on the Freundlich isotherms for 

the five test soils ranged from 0.06 – 0.18 L kg-1. The respective calculated KFOC(ads) values were in the range 

of 4.4 – 25.5 L kg-1, 1/n values were in a range of 0.80 – 1.07. Spirotetramat-MA-amide is classified as very 

highly mobile according to the classification scheme of McCall et al. (1981)1 and highly mobile according to 

FAO2

 classification. 

Reviewer comments:

• Linear adsorption constants (KOC(ads)) were close to the Freundlich adsorption constants with a range 

of 4.2 – 25.6 L kg-1. 

Reference: Estimation of the adsorption coefficient (KOC) of BYI 08330-enol dimer 1 

(ROI 6, 14C-labelled) and BYI 08330-enol dimer 2 (ROI 7, 14C-labelled) on soil 

using High performance Liquid Chromatography (HPLC)

Author(s), year: Neumann, B., Klempner, A., 2006 

Study/report number: M-274184-01-2, MEF-06/123, amended 01.06.2007 

Guideline(s): OECD Guideline 121 (2001) 

GLP: Yes 

Deviations: None 

Validity: Study considered as additional information, only – study not essential

Material and methods:

Test substances: • BYI 08330-enol dimer 1, 0.74 MBq mg-1

• BYI 08330-enol dimer 2, 0.74 MBq mg-1

Both test items isolated from aerobic soil degradation/metabolism study 

conducted with spirotetramat in four soils (Babczinski, 2005) 

Reference substances: NaNO3, aldicarb, atrazine, spirotetramat-ketohydroxy, spirotetramat, methiocarb, 

triadimenol, linuron, spirodiclofen-ketohydroxy, pyrazophos, phenanthrene, 

spirodiclofen, 4,4’-DDT 

Chromatography 

column: 

ZORBAX CN, 5 μm, 250 × 4.6 mm 

Mobile phase: • pH 6.0: methanol/0.01 M citrate buffer (55/45, v/v) 

• pH 1.7: methanol/0.05 M phosphoric acid buffer (55/45, v/v) 

Isocratic elution, 1.5 mL min-1

Calculation: Capacity factor (k’) = (RTsubstance – RTNaNO3)/ RTNaNO3, RTNaNO3 is regarded as 

column dead time, regression analysis log(k’) vs. log(KOC) 

 

1

 McCall, J.P., D.A. Laskowsky, R.L. Swann, and H.J. Dishburger. 1981. Measurement of sorption coefficients of organic 

chemicals and their use in environmental fate analysis. Pages 89-109 In Test protocols for environmental fate & 

movement of toxicants. Proceedings of a symposium. Association of Official Analytical Chemists. 94th Annual Meeting, 

October 21-22, 1980. Washington, DC. 

2

 Food and Agriculture Organization of the United Nations. FAO PESTICIDE DISPOSAL SERIES 8. Assessing Soil 

Contamination: A Reference Manual. Appendix 2. Parameters of pesticides that influence processes in the soil. Editorial 

Group, FAO Information Division: Rome, 2000. 
– 138 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Findings:

Average capacity factors (k’) were derived for each compound and a linear function was established for

log(k’) values vs. log(KOC) values with a slope of 0.253 and 0.295 at pH 6.0 and pH 1.7, respectively, and an 

intercept of -0.478 and -0.628, respectively (R2≥ 0.935). 

y = 0.2528 x - 0.478

R

2

 = 0.9348

-0.2

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

log(KOC)

log(k')

Reference substances

Spirotetramat-enol dimer 1

Spirotetramat-enol dimer 2

y = 0.2948 x - 0.6284

R

2

 = 0.9665

-0.2

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6

log(KOC)

log(k')

Reference substances

Spirotetramat-enol dimer 1

Spirotetramat-enol dimer 2

Figure B.8.2.1.2-1: Calibration plots log(k’) vs. log(KOC) and linear regression lines 

(left: at pH 6.0, right: at pH 1.7). 

Table B.8.2.1.2-20: Calculated KOC values [L kg-1] of spirotetramat-enol dimer 1 and dimer 2 according 

to the HPLC method (corrected by the reviewer). 

Spirotetramat-enol dimer 1 Spirotetramat-enol dimer 2 System 

log(k’) log(KOC) KOC [L kg-1] log(k’) log(KOC) KOC [L kg-1] 

pH 6.0 0.343 3.25 1771 0.405 3.49 3115 

pH 1.7 0.306 3.17 1477 0.409 3.52 3301 

Arithmetic mean - - 1624 - - 3208 

Conclusion:

According to the HPLC method, spirotetramat-enol dimer 1 and spirotetramat-enol dimer 2 can be 

considered as immobile in soil with estimated KOC values of approx. 1624 L kg-1 and 3208 L kg-1. It can be 

concluded that both test items do not have ionic (acidic or alkaline) properties. Spirotetramat-enol dimer 1 is 

classified as lowly mobile according to the classification scheme of McCall et al. (1981) and slightly mobile

according to FAO classification, spirotetramat-enol dimer 2 is classified as slightly mobile according to the 

classification scheme of McCall et al. (1981)1 and according to FAO2 classification. 

Reviewer comments:

• Study not considered essential. Study results included for additional information only. 

• In the study report, log(KOC) was incorrectly set as the dependent variable (y axis) in the calibration 

plots/curves. This was corrected by the reviewer (resulting in a slight change of the results). 

• Reverence substances also include spirotetramat and spirotetramat-ketohydroxy which were both 

well in line with the other test substances confirming the results from individual adsorption/desorption 

batch equilibrium experiments with these two substances. 

 

1

 McCall, J.P., D.A. Laskowsky, R.L. Swann, and H.J. Dishburger. 1981. Measurement of sorption coefficients of organic 

chemicals and their use in environmental fate analysis. Pages 89-109 In Test protocols for environmental fate & 

movement of toxicants. Proceedings of a symposium. Association of Official Analytical Chemists. 94th Annual Meeting, 

October 21-22, 1980. Washington, DC. 

2

 Food and Agriculture Organization of the United Nations. FAO PESTICIDE DISPOSAL SERIES 8. Assessing Soil 

Contamination: A Reference Manual. Appendix 2. Parameters of pesticides that influence processes in the soil. Editorial 

Group, FAO Information Division: Rome, 2000. 
– 139 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

B.8.2.1.3 Column leaching studies with the active substance (OECD Annex IIA, 7.4.3, IIIA, 9.3.1) 

Column leaching studies were not performed for the active studies. Reliable adsorption/desorption parameter 

could be derived with an equilibrium batch study (B.8.2.1.1). 

B.8.2.1.4 Column leaching studies with relevant metabolites (OECD Annex IIA, 7.4.4, IIIA, 9.3.1) 

A column leaching studies was performed with spirotetramat-enol on four soils using [3-14C] labelled test 

item. This study was investigated in an additional modelling study using the transport model HYDRUS. 

Reference: BYI 08330-enol: Soil column leaching 

Author(s), year: Babczinski, P., 2006c 

Study/report number: M-270280-02-2, MEF-05/356, amended 22.05.2006 

Guideline(s): OECD Guideline 312 (2003), US-EPA N §163-1 (1982), SETAC (1995), CAN 

Environmental Chemistry and Fate – Guidelines for Registration of Pesticides 

(1987), PMRA Harmonization of environmental chemistry and fate data 

requirements under NAFTA (2001) 

GLP: Yes 

Deviations: None 

Validity: Study considered acceptable 

Material and methods:

Test substance: [Azaspirodecenyl-3-14C]-spirotetramat-enol, 4.54 MBq mg-1, 

> 99 % of AR radiochemical purity (HPLC), batch BECH 1610 

Reference substances: Spirotetramat-enol (unlabelled), spirotetramat-ketohydroxy, spirotetramat-MAamide 

Application rate: 30.3 μg spirotetramat-enol column-1 (equivalent to 153 g met ha-1 under the 

assumption of 288 g ai ha-1, a worst case formation rate of 50 % and additional 

1/3 amount owing to analytical reasons) 

Soil column: 5 cm diameter, 30 cm length, soil air dried soil: 583 – 836 g corresponding to 760 

– 900 g fresh soil, column leaching tests were performed in duplicate 

Column conditions: Saturated flow conditions, level of ponding CaCl2 solution approx. 1 cm 

Elution: 1000 ml of 0.01 M CaCl2 solution (corresponding to 50.8 cm, pH approx. 6) over a 

period of 5 days (equivalent to approx. 200 ml day-1), leachate collected in 20 ml 

fractions, each group of 5 fractions combined to yield 10 × 100 ml fractions, 

residual eluent from the column (up to 130 cm) additionally collected (11th fraction) 

Column handling: After termination of the leaching process, the column was frozen and cut into 5 × 

6 cm segments. Soil segments were extracted three times with 120 ml of 

acetonitrile/water (1/1, v/v) containing 0.1 % ammonium chloride (w/v) and 0.06 % 

ammonia (v/v), pH approx. 8.6. The extracts were combined and radio-assayed by 

LSC. The soil residues were further extracted with 120 ml of the same extractant 

using a microwave extractor for 10 min at 70 °C, the extract was radio-assayed by 

LSC. All extracts were concentrated (SpeedVac) and analysed by HPLC. 

Remaining soil debris was radio-assed by combustion-LSC. 

Volatile traps: Not in the scope of the study, not applied 

Analytical techniques: LSC, HPLC-UV/RAD, LC-MS/MS 

LOQ ≤ 0.24 % of AR (HPLC, soil segments), ≤ 0.02 % (HPLC, leachates) 

Calculations: Kd values of spirotetramat-enol (mobile fraction) were calculated using the 

following formula (Ketelle and Boyd, 1947 [1]; Swoboda and Thomas, 1968 [2]): 
– 140 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

W

V

V

V

k

v

v

p

d

⋅

















= −1

Vp = Volume of water required to leach 50 % of the test compound through the soil 

column [mL] 

Vv = Void volume of the column [mL] 

W = Soil dry weight in the column [g] 

[1] Ketelle, B. H., Boyd, G. E. (1947) The exchange adsorption of ions from 

aqueous solutions by organic zeolithes. IV. The separation of the Yttrium group 

rare earths. J. Amer. Chem. Soc. 69, 2800-2812 

[2] Swoboda, A. R., Thomas, G. W. (1968) Movement of parathion in soil columns. 

J. Agric. Food Chem. 16, 923-927 

Table B.8.2.1.4-1: Physico-chemical characteristics of test soils used for the column study with 

spirotetramat-enol. 

Soil ‘Laacherhof AXXa’ ‘Laacherhof AIIIa’ ‘Hoefchen’ ‘Molino’ 

Batch ID 20040929 20040929 20040424 20040427 

Geographic 

location 

Monheim/ 

Northrhine-Westfalia/

Germany 

Monheim/ 

Northrhine-Westfalia/

Germany 

Burscheid/ 

Northrhine-Westfalia/

Germany 

Pensacola Florida/ 

USA 

Texture (USDA) Sandy loam Loam Silt loam Sandy loam 

Soil taxonomic 

classification 

(USDA) 

Sandy, mixed, mesic 

Typic Cambudolls 

Sandy, mixed, mesic 

Typic Cambudolls 

Loamy, mixed, mesic 

Typic Argudalfs 

Fine-loamy, kaolinitic, 

thermic Plinthic 

Kandiudults 

SCS Soil series Mollisols, Udolls Alfisols, Udalfs Alfisols, Udalfs Ultisol 

Sand (USDA) [%] 69 49 19 77 

Silt (USDA) [%] 21 31 63 13 

Clay (USDA) [%] 10 20 18 10 

pH (CaCl2) 6.1 6.5 6.4 5.4 

pH (water) 6.6 7.1 6.8 6.0 

pH (KCl) 6.1 6.4 6.2 5.4 

pH (satd. paste) 6.6 7.1 6.8 na 

Organic carbon [%] 2.0 1.2 2.4 0.8 

CEC [meq kg-1] 109 102 141 42 

WHC (0.33 bar) [%] 13.5 17.1 25.6 8.8 

MWHC [%] 29.1 25.7 67.5 22.6 

Findings:

The total recovery of radioactivity of the column including the leachates was in a range of 86.9 – 96.8 % of 

AR (individual values). Since no volatile traps were used complete recovery is not achievable. The total 

radioactivity detected in the leachates was in a range of 2.6 – 17.0 % of AR; from the column segments 70.0 

– 93.4 % of AR could be recovered. Total NER in column segments was in a range of 29.5 – 42.2 % of AR.

Table B.8.2.1.4-2: Material balance [% of AR] at the end of the column study (5 DAT, mean of two 

replicates). 

Soil column Soil 

Extractable NER Sub-total 

Leachate Total 

‘Laacherhof AXXa’ 37.8 42.2 80.1 12.3 92.4 

‘Laacherhof AIIIa’ 33.5 36.5 70.0 17.0 87.0 

‘Hoefchen’ 41.3 40.0 81.3 8.9 90.2 

‘Molino’ 63.8 29.5 93.4 2.6 96.0 
– 141 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

In the soil column recovered radioactivity was focussed on the top soil segment (0 – 6 cm), 64.2 – 77.6 % of 

AR was found within the uppermost segment. The remaining 5 segments (6 – 30 cm) covered 5.8 – 15.8 % 

of AR. 

Table B.8.2.1.4-3: Characterization of total and extractable radioactivity [% of AR] in soil column 

segments at the end of the column study (5 DAT, mean of two replicates). 

Soil column segment [cm] Soil 

0 – 6 6 – 12 12 – 18 18 – 24 24 – 30 Total 

‘Laacherhof AXXa’ 69.4 2.5 2.3 2.8 3.1 80.1 

‘Laacherhof AIIIa’ 64.2 2.3 1.1 1.1 1.3 70.0 

‘Hoefchen’ 70.9 3.3 2.0 2.2 2.8 81.3 

Total 

radioactivity 

‘Molino’ 77.6 9.2 3.9 1.8 0.8 93.4 

‘Laacherhof AXXa’ 29.3 1.6 1.8 2.4 2.6 37.8 

‘Laacherhof AIIIa’ 29.6 1.4 0.7 0.8 1.0 33.5 

‘Hoefchen’ 33.6 2.3 1.4 1.7 2.3 41.3 

Extractable 

radioactivity 

‘Molino’ 49.7 8.4 3.5 1.6 0.6 63.8 

‘Laacherhof AXXa’ 10.2 nd nd nd nd 10.2 

‘Laacherhof AIIIa’ 9.6 nd nd nd nd 9.6 

‘Hoefchen’ 11.5 0.1 nd nd nd 11.6 

Spirotetramatenol 

‘Molino’ 16.5 1.4 nd nd nd 17.9 

‘Laacherhof AXXa’ 1.4 1.1 1.5 2.0 2.4 8.4 

‘Laacherhof AIIIa’ 0.8 0.7 0.5 0.6 0.7 3.3 

‘Hoefchen’ 1.8 0.8 1.0 1.3 1.8 6.7 

Spirotetramatketohydroxy 

‘Molino’ 3.7 2.9 2.8 1.1 0.5 11.0 

‘Laacherhof AXXa’ nd nd 0.1 0.1 0.1 0.3 

‘Laacherhof AIIIa’ nd nd nd nd nd nd 

‘Hoefchen’ 0.1 0.1 0.1 0.2 0.1 0.6 

SpirotetramatMA-amide 

‘Molino’ nd nd 0.1 0.1 nd 0.2 

‘Laacherhof AXXa’ 8.8 nd nd nd nd 8.8 

‘Laacherhof AIIIa’ 9.3 0.3 nd nd nd 9.6 

‘Hoefchen’ 9.4 0.2 nd nd nd 9.6 

Spirotetramatenol-dimer 1 

‘Molino’ 11.8 1.9 nd nd nd 13.7 

‘Laacherhof AXXa’ 4.8 nd nd nd nd 4.8 

‘Laacherhof AIIIa’ 5.9 nd nd nd nd 5.9 

‘Hoefchen’ 6.1 nd nd nd nd 6.1 

Spirotetramatenol-dimer 2 

‘Molino’ 10.7 0.1 nd nd nd 10.8 

‘Laacherhof AXXa’ 4.1 0.6 0.2 0.3 0.4 5.6 

‘Laacherhof AIIIa’ 3.9 0.4 0.2 0.2 0.3 5.0 

‘Hoefchen’ 4.5 1.0 0.3 0.2 0.5 6.5 

Unidentified 

radioactivity 

‘Molino’ 7.0 2.1 0.5 0.4 0.1 10.1 
– 142 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.2.1.4-4: Amounts of total radioactivity, spirotetramat-enol, spirotetramat-ketohydroxy and spirotetramat-MA-amide in leachate fractions

[% of AR] (5 DAT, mean of two replicates). 

Leachate fractiona Soil 

1 2 3 4 5 6 7 8 9 10 11 Total 

‘Laacherhof AXXa’ < 0.1 < 0.1 0.3 1.5 1.8 1.5 1.3 1.2 1.4 1.6 1.6 12.3 ‘Laacherhof AIIIa’ < 0.1 0.1 0.9 1.9 2.6 2.9 2.7 2.2 1.7 1.3 0.6 17.0 ‘Hoefchen’ < 0.1 < 0.1 < 0.1 0.3 0.7 1.0 1.1 1.1 1.3 1.5 1.9 8.9 

Total 

radioactivity 

‘Molino’ < 0.1 < 0.1 0.1 0.4 0.5 0.4 0.3 0.3 0.2 0.2 0.2 2.6 

‘Laacherhof AXXa’ na na na 0.1 0.3 0.5 0.5 0.5 0.4 0.3 0.3 2.8 ‘Laacherhof AIIIa’ na na < 0.1 nd < 0.1 < 0.1 0.2 0.3 0.3 0.3 0.2 1.3 ‘Hoefchen’ na na na nd 0.1 0.3 0.4 0.4 0.5 0.4 0.5 2.7 

Spirotetramatenol 

‘Molino’ na na na nd nd nd nd < 0.1 < 0.1 < 0.1 < 0.1 0.1 

‘Laacherhof AXXa’ na na na < 0.1 0.1 < 0.1 0.1 0.3 0.6 0.8 1.0 2.9 ‘Laacherhof AIIIa’ na na < 0.1 0.3 1.0 1.6 1.6 1.2 0.9 0.7 0.3 7.5 ‘Hoefchen’ na na na nd < 0.1 < 0.1 < 0.1 0.1 0.3 0.5 0.9 2.0 

Spirotetramatketohydroxy 

‘Molino’ na na na nd < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 0.2 

‘Laacherhof AXXa’ na na na 0.8 0.4 0.2 0.1 0.1 0.1 0.1 0.1 1.9 ‘Laacherhof AIIIa’ na na 0.2 0.2 nd < 0.1 0.1 0.1 0.1 < 0.1 < 0.1 0.8 ‘Hoefchen’ na na na 0.1 0.2 0.2 0.2 0.1 0.1 0.1 0.1 1.0 

SpirotetramatMA-amide 

‘Molino’ na na na 0.3 0.4 0.3 0.2 0.1 0.1 0.1 0.1 1.5 

a Each leachate fraction corresponds to 100 mL
– 143 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.2.1.4-5: Calculated KOC [L kg-1] values for spirotetramat-enol from the column experiments. 

Soil Repl. Vp [mL] Vv [mL] W [g] Kd [L kg-1] KOC [L kg-1] Mean 

A 675 327 669 0.52 26 ‘Laacherhof AXXa’ 

B 715 340 669 0.56 28 

27 

A 858 304 710 0.78 65 ‘Laacherhof AIIIa’ 

B 864 312 710 0.78 65 

65 

A 849 368 583 0.83 34 ‘Hoefchen’ 

B 701 368 583 0.57 24 

29 

A 861 260 836 0.72 90 ‘Molino’ 

B 994 272 836 0.86 108 

99 

Vp = Volume of water required to leach 50 % of the test compound through the soil column (including void volume) [mL] 

Vv = Void volume of the column [mL] 

W = Soil dry weight in the column [g] 

The test item spirotetramat-enol was almost exclusively located in the top soil segment (9.6 – 16.5 % of AR). 

Only in the ‘Molino’ soil a small amount of spirotetramat-enol (1.4 % of AR) was detected in the second soil 

segment. In the other three soils spirotetramat-enol was not detected in deeper column segments (≤ 0.1 % of 

AR). 

Other major components detected in the top segment extracts were spirotetramat-enol dimer 1 (8.8 – 11.8 % 

of AR) and spirotetramat-enol dimer 2 (4.8 – 10. 7 % of AR) for which strong evidence is given that their 

formation is artifactual owing to the application technique. Spirotetramat-enol dimer 1 exhibited a little 

potential to move into the second soil segment at very low extent, spirotetramat-enol dimer 2 was completely 

immobile. 

Spirotetramat-ketohydroxy was recovered from the top soil segments in a range of 0.8 – 3.7 % of AR. In

contrast to the spirotetramat-enol and the dimers of spirotetramat-enol, spirotetramat-ketohydroxy was

present in the further segments of all soils after leaching, indicating a certain translocation potential. In 

‘Molino’ soil a decreasing gradient towards the column end was observed, whereas in soils ‘Laacherhof 

AXXa’ and ‘Hoefchen’ this gradient increased. Its behaviour in ‘Laacherhof AIIIa’ soil was less clear.

Spirotetramat-MA-amid was formed from spirotetramat-enol in low amounts. In three of the four soils it was 

found at maximum 0.2 % of AR. This compound had a tendency to move down the columns as well and was 

hardly detected in any of the top and second soil segments. 

Conclusion:

From this study, it is evident that only a tiny portion of spirotetramat-enol had a potential to leach into deeper 

soil layers or leave the soil column, whereas by far the major portion strongly bound to the top soil layer. 

Only a minor part of the applied spirotetramat-enol was recovered in soil extracts and even smaller portion in 

the leachate, indicating immediate and strong binding (chemisorption) to the top soil and to a lower extent 

transformation into spirotetramat-enol derived degradates, but a significant formation of NER during the 

progress of the study. For the mobile (non-bound) spirotetramat-enol fraction KOC values between 27 – 99 

L kg-1 were calculated. Spirotetramat-enol is classified as highly mobile according to the classification 

scheme of McCall et al. (1981)1

 and mobile according to FAO2 classification. 

 

1

 McCall, J.P., D.A. Laskowsky, R.L. Swann, and H.J. Dishburger. 1981. Measurement of sorption coefficients of organic 

chemicals and their use in environmental fate analysis. Pages 89-109 In Test protocols for environmental fate & 

movement of toxicants. Proceedings of a symposium. Association of Official Analytical Chemists. 94th Annual Meeting, 

October 21-22, 1980. Washington, DC. 

2

 Food and Agriculture Organization of the United Nations. FAO PESTICIDE DISPOSAL SERIES 8. Assessing Soil 

Contamination: A Reference Manual. Appendix 2. Parameters of pesticides that influence processes in the soil. Editorial 

Group, FAO Information Division: Rome, 2000. 
– 144 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Reviewer comments:

• The notifier also stated KOC values for the ‘immobile’ spirotetramat-enol fraction in a range of 828 – 

1711 L kg-1. Since this fraction is considered to be strongly bound to the soil matrix via 

chemisorption, the ‘immobile’ fraction is considered immobile per se. Partial transfer into deeper soil 

layers (‘Molino’ soil) may be attributed to (reversible) binding of spirotetramat-enol onto more mobile 

soil compounds (e.g. dissolved organic carbon, etc.). Calculation of KOC values for this tightly bound 

fraction is not considered admissible at all. These data are not considered relevant for further risk 

assessment. (It may be annotated, that the calculation used by the notifier does not result in reliable 

KOC values in the case that no transfer of the test item into deeper soil layers is observed. The 

calculation of the KOC is solely based on the soil depth of maximum occurrence. Since this soil depth 

can only be very roughly estimated within the 0 – 6 cm column segment, calculated KOC values are 

highly indicative and vary considerable assuming a depth of maximum occurrence of e.g. 1 or 3 cm). 

• The reviewer calculated additional KOC values for spirotetramat-ketohydroxy and spirotetramat-MAamide on the basis of the column leachate data, in order to verify the reliability of KOC results 

obtained for spirotetramat-enol. As can be seen in the following table, data from batch equilibrium 

experiments (Hein, 2005a; Simmonds and Early, 2005) and from the column study are highly 

consistent in case of spirotetramat-ketohydroxy and spirotetramat-MA-amide. In this respect, KOC

values obtained for spirotetramat-enol from the column study are considered reliable. 

Table B.8.2.1.4-6: Calculated KOC values for spirotetramat-ketohydroxy and spirotetramat-MA-amid 

on the basis of column leachate data and results obtained from batch equilibrium experiments – 

additional reviewer assessment. 

Vp [mL]a Vv [mL] W [g] Kd

[L kg-1] KOC/KFOC [L kg-1] 

Compound Soil 

Column study Column 

study 

Batch 

studyb

‘Laacherhof AXXa’ 940 334 669 0.91 45 41.0 

‘Laacherhof AIIIa’ 650 308 710 0.48 40 46.9 

‘Hoefchen’ 990 368 583 1.07 44 41.2 

Spirotetramatketohydroxy 

‘Molino’ 760 266 836 0.59 74 99.1 

‘Laacherhof AXXa’ 440 334 669 0.16 7.9 4.4 

‘Laacherhof AIIIa’ 560 308 710 0.35 30 6.5 

‘Hoefchen’ 620 368 583 0.43 18 5.0 

SpirotetramatMA-amide 

‘Molino’ 540 266 836 0.33 41 25.5 

Vp = Volume of water required to leach 50 % of the test compound through the soil column (including void volume) [mL] (estimated by 

the reviewer) 

Vv = Void volume of the column [mL] (mean values) 

W = Soil dry weight in the column [g] (mean values)

b

 Hein (2005a), Simmonds and Early (2005) 

Reference: Analysis of the sorption behaviour of spirotetramat-enol using a column 

leaching experiment 

Author(s), year: Hammel, K., 2007 

Study/Report number: -, MEF-07/220 

Guideline(s): Calculations – not applicable 

GLP: Calculations – not applicable 

Deviations: Calculations – not applicable 

Validity: Study considered as additional information, only – study not essential

Material and methods:

The transport model HYDRUS was used to simulate the behaviour of spirotetramat-enol in a column study 

(Babczinski, 2006c) conducted on four soils. Three contrasting approaches were investigated: 

• Equilibrium sorption model using the KOC of the strongly sorbed spirotetramat-enol 
– 145 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

• Equilibrium sorption model using the KOC of the mobile spirotetramat-enol 

• Non-equilibrium sorption model assuming kinetic adsorption for spirotetramat-enol (as used for the 

environmental risk assessment), input parameter were optimized by inverse modelling 

For the two equilibrium sorption approaches (high and low KOC), degradation of spirotetramat-enol was 

considered to follow DFOP kinetics with a rapid (mobile) and a slow degrading (strongly bound) fraction. 

Adequate rates and sizes for the slow and the fast degrading fraction were derived from Röpke (2006a, 

Table B.8.4.4-7). 

Table B.8.2.1.4-7: DFOP parameter derived from Röpke (2006a) for the degradation of spirotetramatenol in soil used for the equilibrium sorption approaches. 

Parameter Explanation / Calculation ‘Laacherhof 

AXXa’ 

‘Laacherhof 

AIIIa’ ‘Hoefchen’ ‘Molino’ 

g [0 ... 1] Size of the fast degrading (mobile) 

fraction 0.851 0.833 0.888 0.863 

1 – g [0 ... 1] Size of the slow degrading (strongly 

bound) fraction 0.149 0.167 0.112 0.137 

k1 [days-1] Degradation rate of the fast (mobile) 

degrading fraction 40.5 5.2 41.8 15.6 

k2 [days-1] Degradation rate of the slow 

degrading (strongly bound) fraction 0.0098 0.0304 0.0108 0.0109 

For the non-equilibrium sorption approach, input data required in HYDRUS (i.e. Freundlich adsorption 

distribution coefficient in the total system, Kf

 [days-1]; fraction of equilibrium sorption sites, f [0 ... 1]; 

degradation rate constant in the water, kw [days-1]) were optimized for each soil column by inverse modelling 

(using the iterative optimization algorithm of the computer program PEST). Optimization of input data was 

run until adequate fit between measured and modelled amounts in the soil column and in the leachate 

fractions (weighted inversely proportional to the mean of the observation group) was achieved. The kinetic 

sorption constant (kd [days-1]) was directly taken from the SFO-RB modelling approach (Röpke, 2006a). 

Owing to the close conceptual analogy between HYDRUS and PEARL, the HYDRUS input parameters can 

be directly converted into corresponding PEARL parameters (for calculations refer to Table B.8.4.4-10). 
– 146 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.2.1.4-8: Particle density, dry bulk density (Babczinski, 2006c) and calculated porosity and 

gravimetric water concentration of the soil column at saturation. 

Parameter Explanation / Calculation ‘Laacherhof 

AXXa’ 

‘Laacherhof 

AIIIa’ ‘Hoefchen’ ‘Molino’ 

ρr [g cm-3] Particle density 2.59 2.62 2.45 2.63 

ρs [g cm-3] Dry bulk density 1.13 1.23 0.61 0.46 

Φ [-] Porosity, Φ = 1 – ρs/ρr 0.56 0.53 0.61 0.43 

θg [-] 

Gravimetric water content at saturation, 

θg = (Φ × ρw) / ρs, 

ρw = density of the water (i.e. 1 g cm-3) 

0.50 0.43 0.63 0.32 

Table B.8.2.1.4-9: Optimized input parameter (after inverse modelling) of spirotetramat-enol in 

column studies modelled with HYDRUS (coupled to PEST). 

Parameter Explanation ‘Laacherhof 

AXXa’ 

‘Laacherhof 

AIIIa’ ‘Hoefchen’ ‘Molino’ Remarks 

kd [days-1] Kinetic sorption rate 

constant 0.012 0.037 0.012 0.013 Values taken from Röpke (2006a) 

Kf [L kg-1] 

Freundlich adsorption 

distribution coefficient 

(total system) 

18.6 6.39 24.0 22.9 Optimized 

f [0 ... 1] Fraction of equilibrium 

sorption sites 0.036 0.14 0.039 0.050a

 Optimized 

kw [days-1] 

Degradation rate 

constant in the water 

phase 

2.40 2.63 2.14 3.60 Optimized 

a

 Fixed 

Table B.8.2.1.4-10: Calculated PEARL parameter according to optimized HYDRUS input parameter. 

Parameter Explanation / Calculation ‘Laacherhof 

AXXa’ 

‘Laacherhof 

AIIIa’ ‘Hoefchen’ ‘Molino’ 

fne [-] 

Ratio between non-equilibrium and 

equilibrium sorption sites, 

fne = (1 – f) / f 

26.9 6.28 24.7 19.0 

Kf eq [L kg-1] 

Freundlich adsorption distribution 

coefficient in the equilibrium domain, 

Kf eq = Kf / (1 + fne) 

0.67 0.88 0.93 1.14 

kt [days-1] 

Degradation rate constant in the 

equilibrium phase, 

kt = kw / (1+ Kf eq × ρw / θg) 

1.03 0.87 0.86 0.78 
– 147 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Findings:

Figure B.8.2.1.4-1: Modelled and measured depth distribution (top within a soil) and breakthrough 

curve (bottom within as soil) of spirotetramat-enol for the column leaching in soils ‘Laacherhof 

AXXa’ (left, top), ‘Laacherhof AIIIa’ (right, top), ‘Hoefchen’ (left, bottom) and ‘Molino’ (right, bottom). 
– 148 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Conclusion:

The kinetic sorption model best reflects the measured values both in the eluate and distribution in the soil 

column. Whereas the low equilibrium KOC vastly overpredicts leachate concentrations, the high KOC model 

underpredicts transport. The kinetic sorption model therefore offers the best description of the leaching 

behaviour of spirotetramat-enol and is thus the best choice to extrapolate to natural field conditions. 

Reviewer comments:

• Study not considered essential. Study results included for additional information only. 

• A comparison of the kinetic sorption data derived from the spirotetramat-enol degradation study 

applying SFO-RB kinetics (Babczinski, 2006b, Röpke, 2006a) and from inverse modelling of the 

column leaching study shows, that there are some differences in respect to the fne value (arithmetic 

mean 377 vs. 19.2) and the effective degradation rate of spirotetramat-enol (geometric mean 16.6 

vs. 2.64 days-1). However, the KOC values of spirotetramat-enol, calculated from the column study 

(Babczinski, 2006c) and obtained by inverse modelling (this study) are almost consistent (Table 

B.8.2.4.1.-11). In general, one has to be careful comparing the column study and the soil 

degradation study. In contrast to the soil degradation study, the column leaching study was 

conducted under conditions of high water saturation (slow oxygen supply, degradation of 

spirotetramat-enol is strongly driven by oxidation) and the experiment was conducted for only 5 

days. In this respect, the reviewer agrees that the kinetic adsorption data obtained in the column 

study by inverse modelling are not adequate as modelling input parameter for environmental risk 

assessment.
– 149 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.2.1.4-11: Comparison of kinetic sorption parameters required in PEARL, derived from degradation rate study (spirotetramat-enol as parent, 

Babczinski, 2006b; Röpke, 2006a) and from the column study (this study). 

Parameter Explanation Study value deriving from ‘Laacherhof AXXa’ ‘Laacherhof AIIIa’ ‘Hoefchen’ ‘Molino’ Mean 

Column study (inverse modelling, HYDRUS) 33.5 73.3 38.8 142.5 72 (geom.) KOC [L kg-1] KOC of the mobile fraction Column study (calculated, Babczinski, 2006c) 27 65 29 99 55 (geom.) Column study (inverse modelling, HYDRUS) 26.9 6.28 24.7 19.0 19.2 (arith.) 

fne [-] Ratio between non-equilibrium and equilibrium sorption sites Soil degradation rate study (SFO-RB approach, Röpke, 2006a) 693 28.9 594 193 377 (arith.) 

Column study (inverse modelling, HYDRUS) 2.41 2.65 2.13 3.56 2.64 (geom.) 

keff [days-1] Effective degradation rate of the mobile fraction, 

keff = kt × (1 + Ke eq × ρw / θg) 

Soil degradation rate study (SFO-RB approach, Röpke, 2006a) 34.5 4.35 37.1 13.5 16.6 (geom.) 
– 150 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

B.8.2.1.5 Aged residue column leaching studies (OECD Annex IIA, 7.4.5) 

Aged column leaching studies were not performed. This requirement is covered by the adsorption/desorption 

studies with the parent compound and metabolites as presented in B.8.2.1. 

B.8.2.1.6 Leaching (TLC) (OECD Annex IIA, 7.4.6) 

Such data describing the mobility in soil were supplied by higher tier studies shown in all other sections of 

point B.8.2. 

B.8.2.1.7 Lysimeter studies (OECD Annex IIA, 7.4.7, Annex IIIA, 9.3.2) 

The mobility of the spirotetramat residues in soil has been adequately assessed on the basis of the 

adsorption/desorption studies with the parent compound and metabolites (as presented in B.8.2.1). 

B.8.2.1.8 Field leaching studies (OECD Annex IIA, 7.4.8, Annex IIIA, 9.3.3) 

Based on the results of laboratory and modelling studies mentioned in the chapter before it is concluded that 

the mobility of spirotetramat residues in soil is sufficiently understood after its intended use, and no concern 

with regard to groundwater contamination is indicated. This was supported by the terrestrial field dissipation 

studies performed in the USA, since there was no movement measured below a 15-cm depth of soil. Thus, 

field leaching studies were considered not necessary. 

B.8.2.1.9 Volatility laboratory and field study (OECD Annex IIA, 7.4.9, IIIA, 9.3.4, 9.3.5) 

The vapour pressure and Henry’s law constant of spirotetramat were determined to be 5.6 × 10-9 Pa (20 °C) 

and 7.0 × 10-8 Pa m3

 mol-1 (20 °C, pH 7), respectively. Based on these results it was concluded that 

significant volatilization of spirotetramat in the environment is not to be expected. Therefore, no further 

laboratory experiments were considered necessary. 
– 151 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

B.8.2.1.10 Summary on the mobility in soil 

Note: In contrast to the EU risk assessment, the Canadian and US risk assessment is based on linear (nonFreundlich) adsorption isotherms, and deviating input data are used for calculation and modelling of 

predicted/expected environmental concentrations (e.g. the 20th percentile, or the lowest, median value, etc.). 

Respective values are stated in the summary tables together with the endpoints considered relevant for the 

EU risk assessment. 

Reliable adsorption constants according to Freundlich isotherms (equilibrium batch experiments) could be 

achieved for spirotetramat, spirotetramat-ketohydroxy and spirotetramat-MA-amide using 5 soils from 

the EU, USA and Canada with a representative set of soil properties: 

• Soil pH (CaCl2): 4.7 – 6.8 

• Organic carbon: 0.7 – 2.4 % 

• Clay: 7 – 28 % 

No adsorption/desorption constants are available for spirotetramat and metabolites in more alkaline soils 

(pH ≥ 7.0 in CaCl2). However, no dependency of the adsorption behaviour onto the soil pH could be stated in 

the pH range tested. In this respect, it is unlikely that adsorption/desorption under more alkaline conditions 

will significantly differ from values obtained in the tested range. This assumption is also confirmed by 

modelling results from the US field trials, showing a topsoil pH in the range of 6.3 – 8.1 (in water). These field 

trials were fully re-modelled with the (uncalibrated) parameter set used for spirotetramat and metabolites, 

based on KOC values obtained from the tested pH range of 4.7 – 6.8 (for details refer to Röpke and 

Ramanarayanan, 2007). Modelled and measured data were highly consistent also in more alkaline soils. 

Linear adsorption constants (Kd) and Freundlich adsorption constants (KF) of spirotetramat have been 

determined in batch equilibrium experiments with five different soils using the [3-14C] labelled test substance. 

Since significant degradation of the test item was observed in a pre-test, the main test was performed with 

sterilized soil (using mercuric(II)chloride) and the equilibrium time was restricted to 3 hrs. Based on organic 

carbon content, KFOC values for the different soils were in a range of 159 – 435 L kg-1 (arithmetic mean 1/n = 

0.94). Linear adsorption constants (KOC) were close to the Freundlich adsorption constants with a range of 

184 – 437 L kg-1. Based on these values, spirotetramat is classified as medium mobile according to the 

classification scheme of McCall et al. (1981)1 and moderately mobile according to FAO2 classification. 

Adsorption behaviour of spirotetramat-ketohydroxy was investigated in the same soils tested with the

parent, which were once again sterilized using mercuric(II)chloride to inhibit extensive degradation of the test 

compound. Equilibration time was 24 hrs. Obtained KFOC values were in a range of 41.0 – 99.1 L kg-1. 

Respective arithmetic mean 1/n value was 0.92. Linear adsorption constants (KOC) were close to the 

Freundlich adsorption constants with a range of 42.0 – 99.7 L kg-1. Based on these values, spirotetramatketohydroxy is classified as highly mobile according to the classification scheme of McCall et al. (1981) and 

mobile according to FAO classification. 

No significant breakdown of spirotetramat-MA-amide was observed in soil equilibrium experiments, 

obtained KFOC values were in a range of 4.4 – 25.5 L kg-1. Respective arithmetic mean 1/n value was 0.95. 

 

1

 McCall, J.P., D.A. Laskowsky, R.L. Swann, and H.J. Dishburger. 1981. Measurement of sorption coefficients of organic 

chemicals and their use in environmental fate analysis. Pages 89-109 In Test protocols for environmental fate & 

movement of toxicants. Proceedings of a symposium. Association of Official Analytical Chemists. 94th Annual Meeting, 

October 21-22, 1980. Washington, DC. 

2

 Food and Agriculture Organization of the United Nations. FAO PESTICIDE DISPOSAL SERIES 8. Assessing Soil 

Contamination: A Reference Manual. Appendix 2. Parameters of pesticides that influence processes in the soil. Editorial 

Group, FAO Information Division: Rome, 2000. 
– 152 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Linear adsorption constants (KOC) were close to the Freundlich adsorption constants with a range of 4.2 – 

25.6 L kg-1. Based on these values, spirotetramat-MA-amide is classified as very highly mobile according to 

the classification scheme of McCall et al. (1981) and highly mobile according to FAO classification. 

Owing to the extreme instability of spirotetramat-enol once in contact with soil, no reliable adsorption value 

could be determined for this metabolite in a standard batch equilibrium experiment according to guideline 

OECD 107. The rapid disappearance of spirotetramat-enol during these tests is mainly attributed to fast 

transformation to spirotetramat-ketohydroxy (and other degradation products) and to strong binding to the 

soil matrix (chemisorption), which is commonly observed in aerobic soils for this metabolite. In an additional 

study to investigate the time-depending sorption, adsorption and binding of spirotetramat-enol to soil was 

extremely fast and rapidly increased with aging time in soil. The fraction of spirotetramat-enol not tightly 

bound to the soil, i.e. the fraction that can be released by aqueous solutions from soil (mobile fraction), is 

degraded within a few hours (mainly to spirotetramat-ketohydroxy). From this study, it can be concluded that 

spirotetramat-enol is more or less absent from the soil pore water (either degraded or tightly bound to soil) 

within a very short period of time. To obtain more reliable adsorption parameter for spirotetramat-enol, a 

column study using spirotetramat-enol as parent was conducted on four soils (the same soils which were

used for the spirotetramat-enol degradation study). From this study, it is evident that only a small fraction of 

spirotetramat-enol had a potential to leach into deeper soil layers or leave the soil column (≤ 2.8 % of AR in 

leachates), whereas by far the major fraction strongly bound to the top soil layer. Only a minor part of the 

applied spirotetramat-enol (i.e. the mobile fraction) was recovered in soil extracts and even a smaller fraction 

in the leachate, indicating immediate and strong binding to the top soil, transformation into spirotetramat-enol 

derived degradates, and significant formation of NER during the progress of the study. For the mobile 

spirotetramat-enol fraction KOC values between 27 – 99 L kg-1 were calculated. In this respect, spirotetramatenol is classified as highly mobile according to the classification scheme of McCall et al. (1981) and mobile 

according to FAO classification. However, it should be kept in mind that this KOC value is only valid for the 

mobile and fast degrading fraction of spirotetramat-enol (representing the first phase of the distinct bi-phasic 

degradation); the slowly degrading and strongly bound fraction of spirotetramat-enol (representing the

second phase of the biphasic degradation) is considered more or less immobile. 

In order to prove, whether the kinetic adsorption approach, used for spirotetramat-enol in the environmental 

risk assessment, adequately describes the behaviour of the compound observed in the column leaching 

study, the column experiments were fully re-modelled using the program HYDRUS. Several input 

parameters, among them the KOC of spirotetramat-enol, were optimized by inverse modelling, using the 

program PEST, in order to achieve adequate fits between measured and modelled residues in the column 

and in the leachates. Based on these optimization procedures, the KOC of spirotetramat-enol was calculated 

to be within a range of 34 – 143 L kg-1, which is close to the KOC values derived from more straightforward 

calculations based on the amounts of spirotetramat-enol in the leachate fractions, only. 

According to the HPLC method, spirotetramat-enol dimer 1 and spirotetramat-enol dimer 2 show KOC

values of approx. 1624 L kg-1 and 3208 L kg-1. Spirotetramat-enol dimer 1 is classified as lowly mobile 

according to the classification scheme of McCall et al. (1981) and slightly mobile according to FAO 

classification, spirotetramat-enol dimer 2 is classified as slightly mobile according to the classification 

scheme of McCall et al. (1981) and according to FAO classification. However, neither spirotetramat-enol 

dimer 1 nor spirotetramat-enol dimer 2 is considered relevant for further risk assessment. 
– 153 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.2.1.10-1: Summary on adsorption constants of spirotetramat and metabolites. 

Non-linear isotherm (Freundlich) Linear isotherm 

Compound Soil pH (CaCl2) Corg [%] Clay [%] KF(ads) [L kg-1] KFOC(ads) [L kg-1] 1/n R2 Kd(ads) [L kg-1] KOC(ads) [L kg-1] R2 pH depen- dency Method 

‘Laacherhof AXXa’ 6.1 2.38 7.0 4.79 201 1.001 0.980 4.38 184 0.988 ‘Laacherhof AIII’ 6.8 0.87 16.7 3.78 435 0.892 0.993 3.80 437 0.972 ‘Hoefchen’ 5.9 2.33 15.0 4.10 176 0.945 0.994 4.69 201 0.997 ‘Molino’ 5.4 0.93 5.4 4.05 435 0.823 0.976 3.58 385 0.809 ‘Saskatoon’ 4.7 2.33 24.4 3.70 159 1.042 0.903 5.52 237 0.914 Arithmetic mean (EU) - - - nc 281 0.941 - - - - 

Spirotetramat 

20th %ile (PMRA) - - - - - - - 3.76 198 - 

No Batch equilibrium 

‘Laacherhof AXXa’ 6.1 2.0 10 - - 1.00a - 0.54 27 - ‘Laacherhof AIII’ 6.5 1.2 20 - - 1.00a - 0.78 65 - ‘Hoefchen’ 6.4 2.4 18 - - 1.00a - 0.70 29 - ‘Molino’ 5.4 0.8 10 - - 1.00a - 0.79 99 - Arithmetic mean (EU) - - - nc - 1.00 - - 55 - 

Spirotetramatenol 

20th %ile (PMRA) - - - - - - - 0.64 28 - 

No Column study 

‘Laacherhof AXXa’ 6.0 1.30 8.9 0.533 41.0 0.920 1.000 0.560 43.1 0.998 ‘Laacherhof AIII’ 6.4 1.10 13.2 0.516 46.9 0.929 1.000 0.529 48.1 0.997 ‘Hoefchen’ 6.1 2.62 14.7 1.08 41.2 0.927 1.000 1.10 42.0 0.996 ‘Molino’ 6.2 0.87 8 0.862 99.1 0.918 1.000 0.867 99.7 0.994 ‘Saskatoon’ 5.5 2.44 28 2.21 90.4 0.915 1.000 2.28 93.4 0.994 Arithmetic mean (EU) - - - nc 63.7 0.922 - - - - 

Spirotetramatketohydroxy 

20th %ile (PMRA) - - - - - - - 0.55 42.9 - 

No Batch equilibrium 

‘Laacherhof AXXa’ 6.3 1.70 8.9 0.075 4.4 1.07 1.000 0.071 4.2 0.997 ‘Laacherhof AIII’ 6.7 0.91 14.9 0.059 6.5 0.96 0.999 0.064 7.0 0.998 ‘Hoefchen’ 6.5 2.07 14.7 0.104 5.0 0.80 0.998 0.116 5.6 0.976 ‘Molino’ 5.7 0.7 7 0.179 25.5 0.98 0.999 0.179 25.6 0.997 ‘Saskatoon’ 5.4 2.3 25 0.117 5.1 0.93 0.999 0.126 5.5 0.994 Arithmetic mean (EU) - - - nc 9.3 0.95 - - - - 

Spirotetramatketohydroxy 

20th %ile (PMRA) - - - - - - - 0.070 5.2 - 

No Batch equilibrium 

Spirotetramatenol dimer 1b 1624 nd HPLC method Spirotetramatenol dimer 2b 3208 nd HPLC method 

nd denotes not determinable

a Unknown, set to 1.00 to adequately account for the SFO-RB approach (more conservative than the FOCUS default of 0.9) b Spirotetramat-enol dimer 1 and 2 not considered relevant for further risk assessment (artefacts owing to hot spot application in the lab) 
– 154 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

B.8.3 Predicted environmental concentration in soil (PECS) (OECD Annex IIIA, 9.4, 9.5) 

The risk assessment for the EU can be found in the APPENDIX.

The risk assessment for the PMRA and the US-EPA is not included in this monograph. 

The Proposed Registration Decision – Spirotetramat (PRD2008-07), containing the detailed Canadian 

review and risk assessment, has been published by the PMRA and can be found at the PMRA’s web site 

www.pmra-arla.gc.ca. 

The registration decision made by the U.S. EPA's Office of Pesticide Program is supported by the risk 

assessments found at our Federal Docket website located at: 

http://www.regulations.gov/fdmspublic/component/main?main=AdvancedDocket

The Docket ID is "EPA-HQ-OPP-2007-0475". 
– 155 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

B.8.4 Fate and behaviour in the water 

B.8.4.1 Hydrolytic degradation (OECD Annex IIA, 7.5) 

Studies on the hydrolytic degradation were conducted with 

• Spirotetramat (pH 4, 7 and 9), [3-14C] and [5-14C] label 

• Spirotetramat-enol (pH 4, 7 and 9), [3-14C] and [5-14C] label 

Reference: [Azaspirodecenyl-3-14C]- and [Azaspirodecenyl-5-14C]BYI08330: Hydrolytic 

degradation 

Author(s), year: Heinemann, O., 2004a 

Study/report number: M-09312401-2, MEF-04/176 

Guideline(s): 94/37/EC, 95/36/EC, OECD Guideline 111 (2002), US-EPA N 161-1 (1982), 

Canada PMRA DACO 8.2.3.2 (1987), Japan MAFF New Test Guideline 12 

Nousan 8147 (2001) 

GLP: Yes 

Deviations: None 

Validity: Study considered acceptable 

Material and methods:

Test substance: • [Azaspirodecenyl-3-14C]-spirotetramat, 3.71 MBq mg-1, 

> 99 % radiochemical purity (HPLC), batch BECH 0980 and BECH 1518 

• [Azaspirodecenyl-5-14C]-spirotetramat, 4.03 MBq mg-1, 

> 98 % radiochemical purity (HPLC), batch BECH 0981 and BECH 1519 

Labels regarded as replicates 

Reference substances: Spirotetramat (unlabelled), Spirotetramat-enol, Spirotetramat-ketohydroxy 

Test systems: • pH 4: 0.01 M sodium acetate/acetic acid buffer (adjusted with acetic acid) 

• pH 7: 0.01 M tris(hydroxymethyl)aminomethane buffer (adjusted with 0.1 

M HCl and/or 0.1 M NaOH) 

• pH 9: 0.01 M borate buffer (adjusted with 0.4 M NaOH and/or boric acid) 

All buffers sterilized (steam pressure sterilization) and checked for sterility 

throughout the test duration. Oxygen content reduced by nitrogen bubbling. 

Volatile traps: No volatile traps (no volatiles expected – confirmed by complete material balance) 

Test temperature: 50 °C (pre-test), 30 °C (pre-test, pH 9 only), 25 °C (main test) and 20 °C (optional

test, pH 4 and 7 only) 

Test duration: From 7 to 48 days in the dark 

Sample concentration: 1.0 mg L-1

Co-solvent: Acetonitrile (< 0.5 %, v/v) 

Analysis: LSC, HPLC-UV/RAD, TLC, HPLC-MS/MS (ESI) 

LOQ < 1 % of AR 

Kinetic evaluation: Simple first order (SFO) kinetics, ModelManager 1.1, curve fit based on mean 

values of both labels 

Findings:

Mean material balances of all (n = 8) experiments were in a range of 97.2 – 104.4 % of AR. Owing to the 

complete mass balance 14CO2 formation is considered to be negligible. Spirotetramat showed distinct 

hydrolysis at all temperatures and pH value tested, hydrolysis increased with increasing temperature and 

increasing alkalinity. No distinct differences between labels tested occurred. At 25 °C calculated half-life 

times were 32.5, 8.6 and 0.32 days (all SFO, R2

 > 0.99) at a pH of 4, 7 and 9. The only major metabolite 
– 156 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

formed in all tests was the common hydrolysis product spirotetramat-enol, which can be considered to be 

stable under the experimental conditions. Maximum of one unknown peak area was 8.8 % of AR (only using

5-14C labelled parent at 50 °C and at a pH of 4). However, this peak area is considered as artefact, probably 

due to sample autoxidation prior to chromatography. Unidentified radioactivity did not exceed 2.7 % of AR. 
– 157 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.4.1-1: Hydrolysis of spirotetramat in sterile water buffered at pH 4, 7 and 9 [% of AR]. 

pH 4 7 9 

Temperature 50 °C 25 °C 20 °C 50 °C 25 °C 20 °C 30 °C 25 °C 

Compound/ 

Label 

DAT [3-14C] [5-14C] DAT [3-14C] [5-14C] DAT [3-14C] [5-14C] HATa [3-14C] [5-14C] DAT [3-14C] [5-14C] DAT [3-14C] [5-14C] HAT [3-14C] [5-14C] HAT [3-14C] [5-14C]

0 100.0 100.0 0 100.0 100.0 0 100.0 99.2 0 100.0 100.0 0 100.0 99.5 0 100.0 100.0 0 97.0 97.3 0 98.0 97.6 

0.25 99.9 98.0 3 96.4 94.1 5 91.5 91.7 2 90.4 88.8 1 89.8 90.9 5 77.5 75.2 1 75.9 79.4 1 87.2 87.7 

3 71.3 69.6 7 86.4 85.7 8 88.3 89.1 4 82.8 81.9 3 77.4 79.5 8 65.5 65.3 2 61.4 65.5 2 79.0 81.0 4 62.6 60.3 10 79.6 79.4 13 82.3 83.4 8 68.9 69.2 7 55.7 56.0 13 50.2 48.5 3 50.6 53.0 3 72.4 73.3 5 54.7 52.3 14 74.7 74.0 16 78.6 78.9 10 61.8 63.4 13 35.8 35.3 16 42.0 44.5 4 41.0 41.7 4 64.9 65.4 6 51.0 48.6 17 69.8 68.0 19 76.0 75.5 24 32.1 32.6 20 19.2 19.8 19 36.6 35.8 5 33.4 31.5 6 55.6 58.1 7 44.0 43.4 21 65.4 64.4 23 69.8 71.7 30 25.0 24.9 24 15.0 14.0 23 28.7 30.3 6 28.3 26.3 8 47.3 45.9 

10 30.2 29.8 24 60.7 59.4 26 67.2 68.7 48 10.2 11.0 29 10.3 8.9 26 26.4 25.0 7 21.3 22.3 10 na 38.7 12 23.2 22.4 31 52.9 51.0 30 63.5 64.8 30 20.4 20.5 24 9.9 12.5 

Spirotetramat 

30 na 7.1 

0 nd nd 0 nd nd 0 nd nd 0 nd nd 0 nd nd 0 nd nd 0 3.0 2.3 0 2.0 2.4 

0.25 3.0 3.5 3 6.3 6.9 5 7.2 7.0 2 9.6 11.2 1 9.6 9.3 5 24.0 25.0 1 21.6 17.5 1 11.7 11.8 

3 29.1 30.0 7 14.0 14.0 8 10.9 10.8 4 18.6 18.7 3 23.0 23.1 8 36.3 35.8 2 36.6 31.9 2 20.6 20.3 4 39.8 38.1 10 19.2 18.9 13 17.6 16.7 8 33.5 32.4 7 44.5 45.4 13 51.8 53.1 3 47.8 42.9 3 27.8 27.9 5 43.5 43.9 14 26.1 25.4 16 21.0 20.3 10 40.5 38.5 13 65.2 66.5 16 60.4 57.2 4 57.5 56.9 4 35.0 34.6 6 51.5 52.6 17 30.4 30.3 19 23.9 24.8 24 72.1 70.1 20 82.8 83.0 19 65.5 64.0 5 65.2 64.5 6 43.5 44.2 7 58.7 52.9 21 36.0 36.5 23 27.4 27.6 30 79.5 77.8 24 84.1 87.5 23 72.3 71.4 6 70.8 68.1 8 52.3 55.8 

10 71.4 52.2 24 38.3 38.8 26 31.0 30.6 48 93.4 93.4 29 91.4 92.2 26 75.4 73.8 7 75.4 75.9 10 na 64.1 12 75.4 69.3 31 49.8 47.8 30 35.0 33.9 30 81.1 79.9 24 90.0 89.6 

Spirotetramatenol 

 30 na 92.6 

nd denotes not determined na denotes not analysed a HAT denotes hours after treatment. 
– 158 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.4.1-2: Calculated hydrolytic DT50 and DT90 of spirotetramat in sterile water buffered at pH 4, 

7 and 9 using SFO kinetics (mean of both labels). 

pH Temp [°C] DT50 [days] DT90 [days] R2 Kinetics 

50 5.69 18.9 1.00 SFO 

4 25 32.5 108 1.00 SFO 

20 47.6 158 1.00 SFO 

50 0.62 2.08 1.00 SFO 

7 25 8.6 28.7 1.00 SFO 

20 13.1 43.5 1.00 SFO 

30 0.14 0.45 1.00 SFO 9 

25 0.32 1.04 1.00 SFO 

Conclusion:

At environmental relevant conditions spirotetramat is degrading with a half-life of 32.5, 8.6 and 0.32 days at 

pH 4, 7 and 9 and 25 °C. It is concluded that hydrolysis is relevant for the overall elimination of spirotetramat 

in aquatic systems, especially under neutral and alkaline conditions. The only major metabolite deriving from 

hydrolysis of spirotetramat is spirotetramat-enol which is considered to be stable under the experimental 

conditions. 

Reviewer comments:

None 

Reference: [Azaspirodecenyl-3-14C]- and [Azaspirodecenyl-5-14C]BYI08330-Enol: 

Hydrolytic degradation 

Author(s), year: Heinemann, O., 2004b 

Study/report number: M-242999-01-2, MEF-04/311 

Guideline(s): 94/37/EC, 95/36/EC, OECD Guideline 111 (2002), US-EPA N 161-1 (1982), 

Canada PMRA DACO 8.2.3.2 (1987), Japan MAFF New Test Guideline 12 

Nousan 8147 (2001) 

GLP: Yes 

Deviations: None 

Validity: Study considered acceptable 

Material and methods:

Test substance: • [Azaspirodecenyl-3-14C]-spirotetramat-enol, 4.54 MBq mg-1, 

> 99 % radiochemical purity (HPLC), batch BECH 1564

• [Azaspirodecenyl-5-14C]-spirotetramat-enol, 4.99 MBq mg-1, 

> 99 % radiochemical purity (HPLC), batch BECH 1565 

Labels regarded as replicates 

Reference substances: Spirotetramat-enol (unlabelled) 

Test systems: • pH 4: 0.01 M sodium acetate/acetic acid buffer (adjusted with acetic acid) 

• pH 7: 0.01 M tris(hydroxymethyl)aminomethane buffer (adjusted with 0.1 

M HCl and/or 0.1 M NaOH) 

• pH 9: 0.01 M borate buffer (adjusted with 0.4 M NaOH and/or boric acid) 

All buffers sterilized (steam pressure sterilization) and checked for sterility 

throughout the test duration. Oxygen content reduced by nitrogen bubbling. 

Volatile traps: No volatile traps (no volatiles expected – confirmed by complete material balance) 

Test temperature: 50 °C (pre-test) and 25 °C (main test) in the dark 

Test duration: 5 days (pre-test) and 31 days (main test) 

Sample concentration: 1.0 mg L-1
– 159 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Co-solvent: Methanol/aqueous 0.01 M NaHCO3 (1/1, v/v), < 0.3 % of total volume 

Analysis: LSC, HPLC-UV/RAD, TLC, HPLC-MS/MS (ESI) 

LOD < 1 % of AR 

Kinetic evaluation: Simple first order (SFO) kinetics, ModelManager 1.1, curve fit based on mean 

values of both labels 

Findings:

Material balance was in the range of 97.5 – 102.6 % of AR in both experiments for both labels used. No timedependent degradation of spirotetramat-enol was observed, spirotetramat-enol (mean of both labels) 

accounted for 98.2 – 101.2 % of AR throughout the pre-test and 98.0 – 100.5 % of AR in the main test. No 

single radioactive species other than the parent test item occurred at levels > 2.0 % of AR. 

Conclusion:

Spirotetramat-enol is hydrolytically stable under abiotic environmental conditions. Hydrolysis is not expected 

to contribute to the degradation of spirotetramat-enol in the environment. 

Reviewer comments:

None 
– 160 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

B.8.4.2 Photolytic degradation (OECD Annex IIA, 7.6) 

Studies on the photolytic degradation were conducted with spirotetramat in 

• sterile buffered water (pH 5.0), [3-14C] and [5-14C] label 

• sterile natural water (pH 7.9), [3-14C] and [5-14C] label 

Quantum yields and half-life time under environmental conditions were determined for: 

• Spirotetramat 

• Spirotetramat-enol 

Reference: BYI08330: Phototransformation of BYI08330 in sterile water 

Author(s), year: Stupp, H.-P., 2005a 

Study/report number: M-266695-01-2, MEF-05/206 

Guideline(s): 95/36/EC, 94/37/EC, SETAC (1995), US-EPA N 162-1 (1982), Canada PMRA 

DACO 8.2.3.3.2 (1987) 

GLP: Yes 

Deviations: None 

Validity: Study considered acceptable 

Material and methods:

Test substances: • [Azaspirodecenyl-3-14C]-spirotetramat, 3.67 MBq mg-1

, 

> 98 % radiochemical purity (HPLC), batch BECH 0950

• [Azaspirodecenyl-5-14C]-spirotetramat, 4.03 MBq mg-1

, 

≥ 98 % radiochemical purity (HPLC), batch BECH 0952 

Labels regarded as replicates 

Reference substances: Spirotetramat (unlabelled), Spirotetramat-enol 

Test system: Sterile pH 5.0 buffer (0.1 M acetate buffer, autoclaved), adjusted with 0.1 M 

NaOH, sterility was checked throughout the experiment 

Test temperature: 25 ± 1 °C 

Test duration: 7 days continuous irradiation (equivalent to 51.7, 33.3 and 47.0 solar midsummer 

days in at Athens (Greece, EU, 38 °N), Phoenix (AZ, USA, 33 °N) and Edmonton 

(Alberta, CAN, 53 °N), respectively) or dark incubation 

Sample concentration: 1.0 mg L-1

Co-solvent: Acetonitrile (0.1 %, v/v) 

Test system: Xenon arc lamp (Xenotest), cut-off < 290 nm, 990 W m-2 (300 – 800 nm), 22 cm 

above test vessel, light intensity measured by an irradiance sensor 
– 161 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Spectrum of experimental radiation is qualitatively similar to solar irradiation. 

Volatile traps: 1 x soda lime and 1 x polyurethane foam 

Analysis: LSC, HPLC-UV/RAD, TLC, HPLC-MS/MS (ESI), LC-NMR 

LOD = 1 % of AR 

Kinetic evaluation: Simple first order (SFO) kinetics, ModelManager 1.1, curve fit based on mean 

values of both labels 

Findings:

Mass balance was in a range of 93.8 to 108.4 % of AR for all experiments. Under the impact of light small 

amounts (maximum 2.6 % of AR) of 14CO2 were released from the [3-14C] labelled parent indicating 

mineralization at this part of the molecule. Almost no 14C was released from [5-14C] labelled spirotetramat. 

Formation of organic volatiles was negligible. Under irradiation spirotetramat was subjected to extensive 

photolytic rearrangement procedures, resulting in 4 major metabolites: spirotetramat-photo-cyclopentyl

(maximum 42.9 % of AR), spirotetramat-photo-hydroxymethyl (22.9 % of AR), spirotetramat-photo-formyl 

(11.5 % of AR) and spirotetramat-photomethyl carbonate (19.3 % of AR). These major transformation 

products did not decline significantly. Unknown compounds did not exceed 5.5 % of AR individually. Without 

irradiation only the common hydrolysis product spirotetramat-enol was formed. 
– 162 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.4.2-1: Photo-transformation of spirotetramat in sterile water buffered at pH 5 [% of AR]. 

Label Condi- tions DAT CO2 Organic volatiles Spirotetramat Spirotetramat- enol Spirotetramat- photo- cyclopentyl Spirotetramat- photo- hydroxymethyl Spirotetramat- photo- formyl Spirotetramat- photo- methyl carbonate Individual maximum of others (n = 5) Total 

0 na na 100.2 0.0 0.0 0.0 0.0 0.0 0.0 100.2 1 0.1 0.1 72.9 0.0 3.1 16.9 0.0 7.2 0.0 100.2 2 0.2 0.0 64.0 0.0 5.8 18.4 2.8 9.5 0.0 100.9 3 0.8 0.1 36.4 0.0 19.2 16.2 10.7 14.0 5.1 102.5 4 1.3 0.0 34.6 0.0 24.9 22.2 4.9 16.1 0.0 104.0 6 2.6 0.0 16.8 0.0 37.6 15.8 3.5 19.3 4.8 105.7 

Irradiated 

7 2.5 0.8 16.7 0.0 35.4 15.5 6.3 17.0 5.2 108.4 

0 na na 100.9 0.0 0.0 0.0 0.0 0.0 0.0 100.9 1 na na 102.4 2.3 0.0 0.0 0.0 0.0 0.0 104.7 2 na na 93.5 4.2 0.0 0.0 0.0 0.0 0.0 97.7 3 na na 90.5 6.5 0.0 0.0 0.0 0.0 0.0 97.0 4 na na 88.5 9.0 0.0 0.0 0.0 0.0 0.0 97.6 6 na na 84.5 11.7 0.0 0.0 0.0 0.0 0.0 96.1 

[3-14C] 

Dark 

7 na na 84.6 13.7 0.0 0.0 0.0 0.0 0.0 98.3 

0 na na 98.2 0.0 0.0 0.0 0.0 0.0 0.0 98.2 1 0.0 0.3 78.3 0.0 2.3 13.7 0.0 5.5 0.0 100.0 2 0.0 0.0 64.5 0.0 5.4 18.1 2.3 8.8 1.4 100.5 3 0.0 0.0 39.3 0.0 15.1 15.4 11.5 11.7 5.5 103.5 4 0.1 0.0 41.1 0.0 16.6 21.9 3.9 14.7 5.3 103.5 6 0.1 0.0 32.7 0.0 25.3 22.9 3.6 17.2 4.4 106.3 

Irradiated 

7 0.2 0.1 12.0 0.0 42.9 13.8 4.3 18.4 5.2 106.0 

0 na na 101.4 0.0 0.0 0.0 0.0 0.0 0.0 101.4 1 na na 97.5 2.6 0.0 0.0 0.0 0.0 0.0 100.1 2 na na 97.3 4.2 0.0 0.0 0.0 0.0 0.0 101.6 3 na na 86.8 6.9 0.0 0.0 0.0 0.0 0.0 93.8 4 na na 89.5 9.8 0.0 0.0 0.0 0.0 0.0 99.4 6 na na 89.1 12.5 0.0 0.0 0.0 0.0 0.0 101.6 

[5-14C] 

Dark 

7 na na 85.1 13.8 0.0 0.0 0.0 0.0 0.0 98.9 
– 163 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.4.2-2: Calculated photolytic DT50 and DT90 [days] of spirotetramat in 0.01 M acetate buffer at 

pH 5.0 using SFO kinetics (mean value of both labels). 

Experimental Natural conditions 

Conditions DT50

[days] 

DT90

[days] R

2

DT50 [days], 

Athens, Greece, 

EU 

DT50 [days], 

Phoenix, AZ, 

USA 

DT50 [days], 

Edmonton, 

Alberta, Canada 

Kinetics 

Irradiated 2.7 9.0 0.98 12.0a 9.3a 11.4a SFO 

Dark 26.2 86.9 0.89 26.2 26.2 26.2 SFO 

Netb 3.0 10.0 - 22.2 14.4 20.2 SFO 

a

 Re-calculated by the reviewer (see comments) 

b

 Calculated by the reviewer 

Conclusion:

Under irradiated experimental conditions, spirotetramat degraded with a half-life of 2.7 days at a pH of 5 and 

25 °C (SFO kinetics, R2

 = 0.98) owing to photolysis and hydrolysis. This experimental half-life corresponds to 

12.0, 9.3 and 11.4 days under environmental midday summer light in Athens (Greece, EU), Phoenix (AZ, 

USA) and Edmonton (Alberta, Canada). In the dark control DT50 was 26.2 days (owing to hydrolysis) 

indicating that photodegradation of spirotetramat can be considered a significant route for the elimination of 

the compound from the environment. Under the sterile experimental conditions and the impact of light, 

spirotetramat is transformed to the major metabolites spirotetramat-photo-cyclopentyl, spirotetramat-photohydroxymethyl, spirotetramat-photo-formyl and spirotetramat-photomethyl carbonate (all these metabolites 

considered as photo-rearrangement products). Maximum amounts formed were 42.9, 22.9, 11.5 and 19.3 % 

of AR, respectively. Under dark conditions only the common hydrolysis product spirotetramat-enol was 

observed. 

Reviewer comments:

• Labels were handled as replicates. Additional calculations by the reviewer confirmed that the 

degradation of both labels is almost identical (DT50 [3-14C] = 2.5 days, [5-14C] = 2.9 days), therefore 

the usage of a mean value is considered acceptable.

• Based on the net photosynthesis half-life of 3.0 days (calculated by the reviewer), experimental netphotolysis half-life of spirotetramat at pH 5.0 corresponds to 22.2, 14.4 and 20.2 days under 

environmental midday summer light in Athens (Greece, EU), Phoenix (AZ, USA) and Edmonton 

(Alberta, Canada). For calculating the effective degradation half-life under environmental conditions 

(owing to photolysis and hydrolysis), corrected net-photolysis and non-corrected hydrolysis rates 

(expressed as k rates) were summed up. Calculations conducted by the notifier (including hydrolysis 

rate, which was also corrected) are not considered valid. 

Reference: [Azaspirodecenyl-3-14C]BYI08330 and [azaspirodecenyl-3-14C]BYI08330: 

Phototransformation in natural water 

Author(s), year: Stupp, H.-P., 2005b 

Study/report number: M-266753-01-2, MEF-05/262 

Guideline(s): 95/36/EC, 94/37/EC, SETAC (1995), US-EPA N 162-1 (1982), Canada PMRA 

DACO 8.2.3.3.2 (1987) 

GLP: Yes 

Deviations: None 

Validity: Study considered acceptable 

Material and methods:

Test substances: • [Azaspirodecenyl-3-14C]-spirotetramat, 3.67 MBq mg-1

, 

> 98 % radiochemical purity (HPLC), batch BECH 0950

• [Azaspirodecenyl-5-14C]-spirotetramat, 4.03 MBq mg-1

, 
– 164 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

> 98 % radiochemical purity (HPLC), batch BECH 0952

Labels regarded as replicates 

Reference substances: Spirotetramat (unlabelled), Spirotetramat-enol 

Test system: Sterilized (autoclaved) natural water sampled from the Rhine River: 

 pH: 7.93 

 Suspended solids: 25.8 mg L-1

 Total evaporation residue: 273.3 mg L-1

 Oxygen saturation: 98.4 % at 16.5 °C 

 Conductivity: 523 μS cm-1

 TOC: 2 mg L-1

 DOC: < 2 mg L-1

 Hardness: 10.6 °dH 

 Total nitrate: 8.8 mg L-1

 Total phosphorous: 0.1 mg L-1

 UV-Absorption: < 0.05 (290 – 800 nm) 

Test temperature: 25 ± 1 °C 

Test duration: 10 days continuous irradiation (equivalent to 52.2, 33.7 and 47.5 solar midsummer 

days in at Athens (Greece, EU, 38 °N), Phoenix (AZ, USA, 33 °N) and Edmonton 

(Alberta, CAN, 53 °N), respectively) or dark incubation 

Spectrum of experimental radiation is qualitatively similar to solar irradiation. 

Sample concentration: 1.0 mg L-1

Co-solvent: Acetonitrile (0.1 %, v/v) 

Test system: Xenon arc lamp (Xenotest), cut-off < 290 nm, approx. 700 W m-2 (300 – 800 nm), 

22 cm above test vessel, light intensity measured by an irradiance sensor 

Volatile traps: 1 x soda lime and 1 x polyurethane foam 

Analysis: LSC, HPLC-UV/RAD, TLC, HPLC-MS/MS, LC-NMR

LOD = 0.5 % of AR 

Kinetic evaluation: Simple first order (SFO) kinetics, ModelManager 1.1, curve fit based on mean 

values of both labels 

Findings:

Mass balance was in a range of 94.8 to 103.2 % of AR for all experiments. Under the impact of light small 

amounts (maximum 1.1 % of AR) of 14CO2 were released from the [3-14C] labelled parent. Almost no 14C was 
– 165 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

released from [5-14C] labelled spirotetramat. Formation of organic volatiles was negligible. Under irradiation 

in the sterile natural water spirotetramat was subjected to extensive photolytic degradation into several (n ≤

33) metabolites, including spirotetramat-enol (maximum 81.9 % of AR, significantly decreasing thereafter) 

and two further major metabolites, which were only observable using [5-14C] labelled spirotetramat: methoxycyclohexylaminocarboxylic acid (maximum 11.3 % of AR) and methoxycyclohexanone (17.5 % of AR), both 

showing maximum occurrence towards study end. One unidentified peak area reached a maximum 

occurrence of 9.6 % of AR by 8 days decreasing thereafter to 9.1 % of AR by 10 DAT. Further unknown 

compounds did not exceed 5.6 % of AR individually. Without irradiation only the common hydrolysis product 

spirotetramat-enol was formed (complete hydrolysis of the parent). 

Table B.8.4.2-3: Photo-transformation of spirotetramat in sterile natural water at pH 7.9 [% of AR]. 

Label Conditions DAT CO2

Organic 

volatiles 

Spirotetramat 

Spirotetramatenol 

PB1a PB3b

Individual 

maximum 

of others

(n ≤ 33) 

Total 

0 na na 80.4 16.3 0.0 96.7 

1 0.0 0.0 2.6 78.3 2.0 103.2 

2 0.0 0.0 0.0 68.0 2.7 103.2 

3 0.1 1.5 0.0 56.5 4.0 103.2 

6 0.3 0.7 0.0 32.7 7.7 102.9 

8 0.7 1.0 0.0 21.5 9.6 102.7 

Irradiated 

10 1.1 0.7 0.0 14.1 9.1 102.5 

0 na na 88.3 7.9 0.0 96.2 

1 na na 61.7 37.7 0.0 99.3 

2 na na 35.4 64.8 0.0 100.3 

3 na na 21.9 79.1 0.0 101.0 

6 na na 3.7 98.6 0.0 102.4 

8 na na 1.5 100.8 0.0 102.3 

3-14C 

Dark 

10 na na 0.0 102.7 

Not detectable 

using this label 

0.0 102.7 

0 na na 77.5 19.3 0.0 0.0 0.0 96.8 

1 0.0 0.0 1.5 81.9 0.6 3.0 2.0 103.2 

2 0.0 0.0 0.0 72.2 1.5 6.0 2.9 103.2 

3 0.0 0.1 0.0 58.3 2.7 8.1 4.1 102.4 

6 0.1 0.1 0.0 32.1 6.1 15.0 5.2 101.9 

8 0.2 0.1 0.0 17.0 9.9 17.5 5.2 102.5 

Irradiated 

10 0.3 0.1 0.0 16.8 11.3 16.0 5.6 102.5 

0 na na 84.0 10.9 0.0 0.0 0.0 94.8 

1 na na 57.5 40.9 0.0 0.0 0.0 98.4 

2 na na 35.6 64.7 0.0 0.0 0.0 100.3 

3 na na 20.9 78.9 0.0 0.0 0.0 99.8 

6 na na 3.8 97.4 0.0 0.0 0.0 101.2 

8 na na 1.5 100.8 0.0 0.0 0.0 103.0 

5-14C 

Dark 

10 na na 0.0 102.0 0.0 0.0 0.0 102.0 

a

 Methoxy-cyclohexylaminocarboxylic acid 

b

 Methoxycyclohexanone 
– 166 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.4.2-4: Calculated photolytic DT50 and DT90 [days] of spirotetramat in sterile natural water at 

pH 7.9 using SFO kinetics (mean value of both labels). 

Experimental Natural conditions 

Conditions DT50

[days] 

DT90

[days] R

2

DT50 [days], 

Athens, Greece, 

EU 

DT50 [days], 

Phoenix, AZ, 

USA 

DT50 [days], 

Edmonton, 

Alberta, Canada 

Kinetics 

Irradiated 0.19 0.63 1.00 0.66a 0.50a 0.62a SFO 

Dark 1.54 5.11 1.00 1.54 1.54 1.54 SFO 

Netb 0.22 0.71 - 1.15 0.74 1.05 SFO 

a

 Re-calculated by the reviewer (see comments) 

b

 Calculated by the reviewer 

Conclusion:

Under irradiated experimental conditions, spirotetramat extensively degraded with a half-life of 0.19 days in a 

sterilized natural water at pH 7.9 and 25 °C (SFO kinetics, R2

 = 1.00) owing to photolysis and hydrolysis. 

This experimental half-life corresponds to 0.66, 0.50 and 0.62 days under environmental midday summer 

light in Athens (Greece, EU), Phoenix (AZ, USA) and Edmonton (Alberta, Canada). In the dark control, DT50

was 1.54 days (owing to hydrolysis) indicating that photodegradation of spirotetramat can be considered as a 

significant route for the elimination of the compound from the environment. Two major phototransformation 

products were formed besides the common hydrolysis product spirotetramat-enol: methoxycyclohexylaminocarboxylic acid (maximum 11.3 % of AR at study termination) and methoxycyclohexanone 

(17.5 % of AR). Under dark conditions only spirotetramat-enol was formed owing to hydrolysis. 

Reviewer comments:

• Based on the net photosynthesis half-life of 0.22 days (calculated by the reviewer), experimental netphotolysis half-life of spirotetramat at pH 7.9 corresponds to 1.1, 0.7 and 1.0 days under 

environmental midday summer light in Athens (Greece, EU), Phoenix (AZ, USA) and Edmonton 

(Alberta, Canada). For calculating the effective degradation half-life under environmental conditions

(owing to photolysis and hydrolysis), corrected net-photolysis and non-corrected hydrolysis rates 

(expressed as k rates) were summed up. Calculations conducted by the notifier (including hydrolysis, 

which was also corrected) are not considered valid.

• This photolysis study in sterile natural water was conducted to demonstrate that photorearrangement products observed under photolysis in sterile buffer solution at pH 5 (Stupp, 2005a) 

are not likely to occur under more natural conditions. However, based on the contrasting pH value of 

both photolysis studies (pH 5.0 in sterile buffer solution vs. pH 7.9 in sterile natural water) no final 

conclusion on the occurrence of photo-rearrangement product in sterilized natural water in more 

acidic water can be drawn from the study results per se. However, based on the rapid degradation 

half-life (dark rate) of spirotetramat in water/sediment systems (pH 6.7 and 7.2) of approx. 0.8 days 

(Menke, 2006b, Röpke, 2006b) a significant formation of photo-rearrangement products as observed 

in Stupp (2005a), in which spirotetramat showed a dark hydrolysis rate of 26.2 days, is highly 

unlikely to occur. 
– 167 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Reference: BYI08330: Determination of the quantum yield and assessment of the 

environmental half-life of the direct photodegradation in water 

Author(s), year: Heinemann, O., 2004c 

Study/report number: M-092941-01-2, MEF-04/080 

Guideline(s): Phototransformation of Chemicals in Water, part A: Direct Phototransformation, 

UBA, Berlin, Germany (1992-12); Test Method: ECETOC (Polychromatic Light 

Source), US-EPA Guideline No. 161-2 SUPP 

GLP: Yes 

Deviations: None 

Validity: Study considered acceptable (see comments) 

Material and methods:

Light source: Mercury immersion lamp TQ 150 (cut-off filter < 295 nm) 

Actinometer solution: Uranyl oxalate (0.01 mol L-1 uranyl ions, 0.05 mole L-1 oxalic acid) 

Exposure of actinometer solution: 10 min at 25 °C 

Test solution: Spirotetramat (unlabelled), 5.0 mg L-1 in Milli-Q-water (unbuffered) 

Exposure of test solution: 4 hrs 

Range of wave-lengths investigated: 295 – 490 nm 

Analysis of parent degradation: HPLC-UV 

UV/VIS-spectra of test substance: In test solution and in buffered solutions at pH 4, 7 and 9 (all 0.01 M, 

10.0 mg test item L-1) 

Modelling of environmental half-life: a) GC-SOLAR 

b) Frank & Klöpffer 

Findings:

Based on actinometer (uranyl oxalate) degradation, a radiation intensity of approx. 6.80 × 1016 photons 

(sec × 3 ml)-1 was calculated for the test unit. The UV/VIS absorption spectrum of 10.0 mg L-1 spirotetramat 

in pure water shows a maximum below 210 nm and a shoulder at approx. 218 nm, determination of 

absorption was measured above 490 nm. The UV/VIS spectra of spirotetramat in the buffered solutions 

showed comparable absorption properties. The degradation of spirotetramat under test conditions 

(unbuffered solution in water) accounted for approx. 56 % over an irradiation period of 4 hrs. Mean 

degradation half-life under the experimental conditions was calculated to be 0.15 days (SFO kinetics). Based 

on the degradation and the adsorption data, this resulted in a mean quantum yield of direct phototransformation in aqueous solutions of Φ = 0.00571. 

The environmental half-life of spirotetramat, calculated according to GC-SOLAR using the quantum yield of 

Φ = 0.00571 and the molar extinction coefficients from 297.5 to 490 nm were spread from 0.5 – 8.7 days 

depending on the latitude and the season. 

Table B.8.4.2-5: GC-SOLAR modelling: Environmental direct photo-transformation half-life [days] of 

spirotetramat based on the quantum yield. 

Season 30 ° lat. 40 ° lat. 50 ° lat. 60 ° lat. 

Spring 0.53 0.56 0.62 0.73 

Summer 0.48 0.48 0.49 0.52 

Fall 0.73 0.92 1.32 2.41 

Winter 0.96 1.44 2.80 8.71 
– 168 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

In contrast to the GC-SOLAR model, the arithmetic model developed by Frank & Klöpffer21 takes the 

conditions of cloudiness in Central Europe into consideration. The environmental half-life of spirotetramat, 

calculated according to Frank & Klöppfer modelling using the quantum yield of Φ = 0.00571 and the molar 

extinction coefficients from 292.5 to 490 nm, were spread from 0.5 to 52 days depending on the month. 

Table B.8.4.2-6: Frank & Klöpffer modelling: Environmental direct photo-transformation half-life 

[days] of spirotetramat in Central Europe based on the quantum yield. 

Month Minimum Mean Maximum 

January 3.2 6.6 30 

February 1.6 3.3 14 

March 0.90 1.7 7.1 

April 0.58 1.0 4.1 

May 0.51 0.82 3.3 

June 0.49 0.73 2.9 

July 0.55 0.82 2.7 

August 0.56 0.83 2.8 

September 0.84 1.4 5.3 

October 1.3 2.5 12 

November 2.4 5.6 28 

December 4.7 10 52 

Conclusion:

A mean quantum yield of Φ = 0.00571 was calculated for spirotetramat. Based on the different arithmetic 

models (GC-SOLAR and Frank & Klöpffer) by means of resulting quantum yield and adsorption an 

environmental direct photo-transformation half-life of spirotetramat in a range of approx. 0.5 to approx. 1 day 

(mean) can be assessed for the periods of main use (late spring to summer). Direct phototransformation in 

water significantly contributes to the overall elimination of spirotetramat in the environment. 

Reviewer comments:

• Dark hydrolysis rate of spirotetramat is not mentioned (not measured) in the report but is essential to 

calculate net-photolysis rate. However, on request, the notifier gave the information that the Milli-Q

water used had a pH of 6.2 – 6.4. Based on this pH value (dissolved spirotetramat is not expected to 

significantly shift the pH value) the hydrolysis DT50 of spirotetramat is approx. 15 days. Considering 

an exposure period of 240 min (0.17 days) no significant degradation of spirotetramat owing to 

hydrolysis in the dark is expected. In this respect, the study results (assuming a zero dark rate) are

considered valid. 

Reference: BYI08330-Enol: Determination of the quantum yield and assessment of the 

environmental half-life of the direct photodegradation in water 

Author(s), year: Heinemann, O., 2005b 

Study/report number: M-243787-01-2, MEF-04/438 

Guideline(s): Phototransformation of Chemicals in Water, part A: Direct Phototransformation, 

UBA, Berlin, Germany (1992-12); Test Method: ECETOC (Polychromatic Light 

Source), US-EPA Guideline No. 161-2 SUPP 

GLP: Yes 

Deviations: None 

Validity: Study considered acceptable 

 

21 Frank, R., Klöpffer, W.: UBA Research Report No. 10602046 (1985) 
– 169 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Material and methods:

Light source: Mercury immersion lamp TQ 150 (cut-off filter < 295 nm) 

Actinometer solution: Uranyl oxalate (0.01 mol L-1 uranyl ions, 0.05 mole L-1 oxalic acid) 

Exposure of actinometer solution: 10 min at 25 °C 

Test solution: Spirotetramat-enol (unlabelled), 5.03 mg L-1 in Milli-Q-water 

(unbuffered) 

Exposure of test solution: 8.3 hrs 

Range of wave-lengths investigated: 295 – 490 nm 

Analysis of parent degradation: HPLC-UV 

UV/VIS-spectra of test substance: In test solution and in buffered solutions at pH 4, 7 and 9 (all 0.01 M, 

10.3 mg test item L-1) 

Modelling of environmental half-life: a) GC-SOLAR 

b) Frank & Klöpffer 

Findings:

Based on actinometer (uranyl oxalate) degradation, a radiation intensity of approx. 7.25 × 1016 photons 

(sec × 3 ml)-1 was calculated for the test unit. The UV/VIS absorption spectrum of 10.3 mg L-1 spirotetramatenol in buffered solutions at pH 7 and pH 9 showed comparable absorption properties with a distinct 

maximum about 270 nm. In contrast, the UV/VIS absorption spectrum in buffered solution at pH 4 showed no 

such maximum. The degradation of spirotetramat-enol under test conditions accounted for approx. 20 % 

over an irradiation period of 8.3 hrs. Mean degradation half-life under the experimental conditions 

(unbuffered solution in water) was calculated to be 1.39 days (SFO kinetics). Based on the degradation and 

the adsorption data, this resulted in a mean quantum yield of direct photo-transformation in aqueous 

solutions of Φ = 0.000252. 

The environmental half-life of spirotetramat-enol, calculated according to GC-SOLAR using the quantum 

yield of Φ = 0.000252 and the molar extinction coefficients from 297.5 to 490 nm were spread from 8.6 – 173 

days depending on the latitude and the season. 

Table B.8.4.2-7: GC-SOLAR modelling: Environmental direct photo-transformation half-life [days] of 

spirotetramat-enol based on the quantum yield. 

Season 30 ° lat. 40 ° lat. 50 ° lat. 60 ° lat. 

Spring 9.6 10 12 14 

Summer 8.6 8.7 9.0 9.6 

Fall 13 17 25 47 

Winter 18 28 55 173 

In contrast to the GC-SOLAR model, the arithmetic model developed by Frank & Klöpffer4 takes the 

conditions of cloudiness in Central Europe into consideration. The environmental half-life of spirotetramat, 

calculated according to Frank & Klöppfer modelling using the quantum yield of Φ = 0.000252 and the molar 

extinction coefficients from 292.5 to 490 nm, were spread from 9.1 to 1100 days depending on the month. 
– 170 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.4.2-8: Frank & Klöpffer modelling: Environmental direct photo-transformation half-life 

[days] of spirotetramat-enol in Central Europe based on the quantum yield. 

Month Minimum Mean Maximum 

January 65 140 620 

February 31 65 280 

March 17 33 140 

April 11 20 78 

May 9.5 15 61 

June 9.1 14 54 

July 10 15 51 

August 10 16 52 

September 16 27 100 

October 26 50 230 

November 49 110 570 

December 98 220 1100 

Conclusion:

A mean quantum yield of Φ = 0.000252 was calculated for spirotetramat-enol, the major metabolite of the 

parent spirotetramat. Based on the different arithmetic models (GC-SOLAR and Frank & Klöpffer) by means 

of resulting quantum yield and adsorption an environmental direct photo-transformation half-life of 

spirotetramat in a range of approx. 9 to approx. 16 days (mean values) can be assessed for the periods of 

main use (late spring to summer). Direct phototransformation in water is likely to contribute to the overall 

elimination of spirotetramat-enol in the environment. 

Reviewer comments:

• No dark control samples were included in the test design to account for hydrolysis processes. 

However, owing to the high stability of spirotetramat-enol in sterile buffer solutions at pH values from 

4 to 9 (Heinemann, 2004b), the study is considered valid (no hydrolysis assumed). 
– 171 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

B.8.4.3 Ready biodegradability of the active substance (OECD Annex IIA, 7.7) 

Reference: BYI 08330 Biodegradation 

Author(s), year: Weyers, A., 2005 

Study/Report number: M-263287-01-1, 2005/0077/01 

Guideline(s): ECCD 92/69/EEC C.4-D, OECD 301 F 

GLP: Yes 

Deviations: None 

Validity: Study considered acceptable 

Material and methods:

Test substance: Spirotetramat (unlabelled), purity 97.4, batch MIX-Batch 08045/0014 

Reference substance: Na-benzoate 

Inoculum: Aeration tank of a waste water plant treating predominately domestic sewage 

(30 mg L-1) 

Treatments: • Blank control 

• Reference substance: Na-benzoate (100 mg L-1) 

• Test substance: Spirotetramat (100 mg L-1) 

• Toxicity control: Spirotetramat (100 mg L-1) and Na-benzoate (100 mg L-1) 

pH of the test vessel at the end of test: 7.3 

Analysis: Biochemical oxygen demand (corrected for oxygen consumption by nitrification) 

Incubation conditions: 22 ± 2 °C, 28 days 

Findings:

Table B.8.4.3-1: Biodegradation of spirotetramat and reference compound [% of theoretically 

possible degradation]. 

DAT Reference substance Test substance Toxicity control 

4 73 0 29 

12 88 1 37 

20 91 0 38 

28 91 1 40 

Within 28 days almost no degradation (maximum 1 %) was determined for spirotetramat. The reference 

substance (Na-benzoate) has reached level for ready biodegradability by 14 days. 

Conclusion:

Spirotetramat is considered to be not readily biodegradable. 

Reviewer comments:

None 
– 172 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

B.8.4.4 Degradation in aquatic systems (OECD Annex IIA, 7.8) 

B.8.4.4.1 Aerobic biodegradation in aquatic systems (OECD Annex IIA, 7.8.1) 

This point is covered by section B.8.4.4.3. 

B.8.4.4.2 Anaerobic biodegradation in aquatic systems (OECD Annex IIA, 7.8.2) 

This point is covered by section B.8.4.4.3. 

B.8.4.4.3 Water/sediment studies (OECD Annex IIA, 7.8.3) 

Two water sediment studies were conducted: 

• Aerobic water/sediment study with two test systems, [3-14C] and [5-14C] label 

• Anaerobic water/sediment study with one test system, [3-14C] label 

Reference: BYI08330: Aerobic Aquatic Metabolism 

Author(s), year: Menke, U., 2006c 

Study/report number: M-269307-01-2, MEF-04/511 

Guideline(s): 95/36/EC, OECD Guideline 308 (2002), US-EPA N 162-4 (1982) 

GLP: Yes 

Deviations: None 

Validity: Study considered acceptable 

Material and methods:

Test substances: • [Azaspirodecenyl-3-14C]-spirotetramat, 3.67 MBq mg-1

, 

> 98 % radiochemical purity (HPLC), batch BECH 0955

• [Azaspirodecenyl-5-14C]-spirotetramat, 4.03 MBq mg-1

, 

> 98 % radiochemical purity (HPLC), batch BECH 0956 

Labels regarded as replicates 

Reference substances: Spirotetramat (unlabelled), spirotetramat-enol, spirotetramat-ketohydroxy, 

spirotetramat-MA-amide, spirotetramat-di-hydroxy, spirotetramat-oxo-enol, 

benzoic acid 

Application rate: 29 μg L-1 (under the assumption of 288 g ai ha-1, 100 cm water depth) 

Co-solvent: Acetonitrile (0.015 %, v/v) 

Incubation set-up: 102.4 g (‘Hönniger Weiher’) and 182.1 g (‘Anglerweiher’) dry sediment (2 mm 

sieved), 519 mL of water (sediment/water, 1/3, w/v), equivalent to 2 cm sediment 

and 6 cm water column, water phase kept in motion by stirring, sediment stagnant 

Acclimatization period: Approx. 7 days 

Test duration: 120 days 

Incubation conditions: 20 ± 1 °C in darkness 

Volatile traps: Polyurethane foam (organic volatiles), soda lime (CO2), identity of 14CO2

confirmed by Grignard Reaction 

Monitoring: pH, O2, redox potential 

Analysis: Water phase radio-assayed by LSC and concentrated using a speedvac 

concentrator. 
– 173 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Sediment phase extracted 3 times with 100 ml of acetonitrile/water/formic acid 

(50/50/0.5, v/v/v). All three extracts were combined (‘organic extract’). Then the 

sediment was extracted 2 times with 100 ml of acetonitrile/1 M HCl (50/50, v/v) 

and once with 100 ml of pure acetonitrile (all three combined to ‘acid extract’). 

Organic extracts were separately concentrated using a speedvac concentrator. 

Aliquots of the acidic extracted soils from 120 DAT samples were separated into 

humic acids, fulvic acids and humins. 

Non extractable residues were radio-assayed by combustion LSC. 

LOQ(HPLC) approx. 0.5 – 0.8 % of AR 

Analytical techniques: LSC, HPLC-UV/RAD, TLC, LC-MS/MS (ESI) 

Kinetic evaluation: Simple first order (SFO) kinetics, MatLab 

Table B.8.4.4.3-1: Physicochemical characteristics of the water/sediment matrices. 

Name ‘Hönniger 

Weiher’ ‘Anglerweiher’ 

Geographic location 

Wipperfürth, 

NorthrhineWestfalia, 

Germany 

Leverkusen, 

NorthrhineWestfalia, 

Germany 

Type of aquatic system Meso-

/oligotrophic Oligotrophic 

Texture (USDA) Loam Loamy sand 

Sand (USDA) [%] 32.9 81.0 

Silt (USDA) [%] 49.8 11.3 

Clay (USDA) [%] 17.3 7.7 

pH (0.01 M CaCl2) 5.6 6.8 

pH (water) 6.1 7.3 

Organic C [%] 4.42 0.99 

Total N [%] 0.35 0.09 

CEC [meq Ba2+ kg-1] 165 61 

Carbonate [%] 0.3 < 0.1 

Total P [mg kg-1] 770 224 

Redoxpotential [mV] -159 -54 

Water content [%] 58.1 33.7 

Sediment 

Microbial activity [mg CO2 h-1 kg-1] – sampling / start / 120 DAT 36 / 43 / 25 10 / 10 / 8 

pH (sampling) 6.68 7.16 

Total hardness [°dH] 4.3 10.2 

Oxygen content [mg L-1] – sampling / 120 DAT 3.08 / 7.23 6.60 / 7.77 

Redoxpotential [mV] – sampling / 120 DAT 455 / 378 461 / 366 

DOC [mg L-1] 4 < 2 

Total N [mg L-1] 5.2 5.6 

Water 

Total P [mg L-1] 0.11 < 0.03 

Findings:

The oxygen content of the water phase of the samples was in a range of 7.2 – 8.5 mg L-1 (‘Hönniger Weiher’) 

and 7.7 – 8.3 mg L-1 (‘Anglerweiher’), indicating aerobic conditions throughout both experiments. The pH in 

the water phase was slightly increasing from 6.8 by 0 DAT to approx. 7.5 by 120 DAT (‘Hönniger Weiher’) 

and from 7.9 – 8.2 (‘Anglerweiher’). In the sediment the pH stayed more or less unchanged with values about 

6.8 (‘Hönniger Weiher’) and 7.3 (‘Anglerweiher’). The redox potential in the water phase was fairly constant 

in a range of +353 – +428 mV (‘Hönniger Weiher’) and +351 – +397 mV (‘Anglerweiher’), in the sediment the 

redox potential was in a range of +42 – +189 mV (‘Hönniger Weiher’) and +154 – +360 mV (‘Anglerweiher’) 

with a steady decrease in the initial time of the latter test system. In summery, in both systems water and 

sediment stayed aerobically throughout the study period. 
– 174 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Total mass balance was in a range of 94.4 – 102.6 % of AR for both systems and both labels. Formation of 

14CO2 using 3-14C accounted for maximum of 11.0 % (‘Hönniger Weiher) and 24.0 % (‘Anglerweiher’) of AR 

at study termination. Formation of 14CO2 from 5-14C labelled spirotetramat was approx. half indicating that 

this part of the molecule is less available to biodegradation than the 3-14C position. Formation of NER 

steadily increased in both systems towards study termination with a maximum of 40.7 % of AR by 91 DAT.

Spirotetramat quickly degraded in both water/sediment systems, by 7 DAT no spirotetramat was detectable 

in the water or in the sediment phase. Transfer of the test item into the sediment phase was almost negligible 

with a maximum occurrence of 3.4 % of AR by 1 DAT. No distinct differences between labels used were 

observed. Degradation of spirotetramat led to extinct formation of the common hydrolysis product 

spirotetramat-enol (maximum 99.0 % of AR by 14 DAT in the entire system of ‘Hönniger Weiher’ and 92.1 % 

of AR by 7 DAT in ‘Anglerweiher’). Maximum amounts of spirotetramat-enol found in the sediment were 

41.2 % and 15.7 % of AR (‘Hönniger Weiher’ and ‘Anglerweiher’). After reaching maximum, amounts of 

spirotetramat-enol significantly decreased thereafter in both, water and sediment. As a second major 

metabolite spirotetramat-ketohydroxy was formed > 10 % of AR in the entire system with a more or less 

increasing trend towards study termination (maximum in water, sediment, entire system: 17.4 %, 42.8 % and 

50.8 % of AR, respectively). Three further identified metabolites (spirotetramat-MA-amide, spirotetramat-oxoenol isomer and spirotetramat-di-hydroxy) did not exceed 9.2 %, 6.0 % and 9.8 % of AR, respectively (all 

significantly decreasing thereafter). Unidentified radioactivity (sum) was below 8.1 % of AR in the entire 

system of both test systems. 

Table B.8.4.4.3-2: Distribution and recovery of radioactivity [% of AR] after application of [3-14C] or [5-

14C] labelled spirotetramat (288 g ai ha-1) to the aerobic water/sediment system ‘Hönniger Weiher’. 

Sediment 

Label DAT 14CO2

Organic 

volatiles Water Organic 

extract 

Acid 

extract Total 

NER Total 

0 na na 98.8 2.3 0.4 2.7 0.2 101.6 

0.2 < 0.1 < 0.1 92.5 4.6 0.8 5.4 0.2 98.2 

1 < 0.1 < 0.1 86.4 10.4 1.6 12.0 0.8 99.2 

3 < 0.1 < 0.1 83.5 13.9 1.9 15.8 0.8 100.2 

7 0.1 < 0.1 78.6 18.2 2.7 20.9 0.7 100.3 

14 0.2 < 0.1 69.2 24.4 3.0 27.4 1.2 97.8 

30 2.1 < 0.1 26.9 17.3 20.9 38.2 30.0 97.3 

60 3.7 < 0.1 29.2 17.3 17.7 35.0 29.4 97.3 

91 8.0 < 0.1 22.7 15.7 17.8 33.5 32.0 96.2 

3-14C 

120 11.0 < 0.1 17.8 14.9 19.9 34.8 32.9 96.4 

0 na na 94.8 1.5 0.1 1.6 < 0.1 96.4 

0.2 < 0.1 < 0.1 94.4 5.2 0.8 6.0 0.2 100.6 

1 < 0.1 < 0.1 87.7 9.6 1.4 11.0 0.5 99.2 

3 < 0.1 < 0.1 84.0 12.3 1.8 14.1 0.6 98.7 

7 0.1 < 0.1 76.0 19.1 3.1 22.2 1.1 99.5 

14 0.1 < 0.1 70.7 26.7 3.2 29.9 0.8 101.5 

30 0.8 < 0.1 24.3 19.7 21.7 41.4 31.7 98.1 

60 2.2 < 0.1 12.9 18.6 31.4 50.0 36.7 101.8 

91 4.2 < 0.1 7.6 14.0 29.4 43.4 40.7 95.9 

5-14C 

120 5.9 < 0.1 8.2 13.8 30.2 44.0 36.3 94.4 
– 175 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.4.4.3-3: Distribution and recovery of radioactivity [% of AR] after application of [3-14C] or [5-

14C] labelled spirotetramat (288 g ai ha-1) to the aerobic water/sediment system ‘Anglerweiher’. 

Sediment 

Label DAT 14CO2

Organic 

volatiles Water Organic 

extract 

Acid 

extract Total 

NER Total 

0 na na 95.5 1.4 0.2 1.6 < 0.1 97.1 

0.2 < 0.1 < 0.1 93.3 4.2 0.4 4.6 0.1 97.9 

1 < 0.1 < 0.1 90.4 7.9 1.3 9.2 1.0 100.7 

3 0.1 < 0.1 88.2 8.6 2.0 10.6 2.0 100.9 

7 0.1 < 0.1 83.3 12.4 2.5 14.9 3.8 102.2 

14 0.4 < 0.1 79.2 14.0 4.0 18.0 5.0 102.6 

30 3.0 < 0.1 49.3 11.4 15.5 26.9 22.1 101.3 

60 10.2 < 0.1 34.2 9.2 15.0 24.2 29.3 98.0 

91 19.7 < 0.1 27.3 6.5 14.9 21.4 30.4 98.8 

3-14C 

120 24.0 < 0.1 20.2 7.4 15.7 23.1 32.3 99.6 

0 na na 97.5 1.8 0.2 2.0 < 0.1 99.5 

0.2 < 0.1 < 0.1 94.8 4.3 0.4 4.7 0.2 99.6 

1 < 0.1 < 0.1 89.4 8.1 1.3 9.4 1.2 100.0 

3 0.1 < 0.1 87.3 8.2 1.9 10.1 2.2 99.6 

7 0.1 < 0.1 80.9 13.0 2.8 15.8 3.6 100.4 

14 0.2 < 0.1 77.3 14.6 3.5 18.1 4.8 100.3 

30 1.2 < 0.1 54.6 13.7 14.0 27.7 18.4 98.9 

60 3.7 < 0.1 31.2 15.9 17.3 33.2 30.5 98.7 

91 8.2 < 0.1 24.0 14.4 18.8 33.2 33.2 98.6 

5-14C 

120 13.5 < 0.1 17.3 13.2 18.8 32.0 33.9 96.7 
– 176 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.4.4.3-4: Characterization of extractable radioactivity [% of AR] after application of [3-14C] or [5-14C] labelled spirotetramat (288 g ai ha-1) to the 

aerobic water/sediment system ‘Hönniger Weiher’. 

Spirotetramat Spirotetramat-enol Spirotetramat-ketohydroxy Spirotetramat-MA-amide Unidentified RA 

Label DAT Water Sed. Entire system Water Sed. Entire system Water Sed. Entire system Water Sed. Entire system Water Sed. Entire system 

0 82.4 2.2 84.6 15.7 < LOQ 15.7 < LOQ < LOQ < LOQ < LOQ < LOQ < LOQ 0.7 0.5 1.2 

0.2 70.2 3.1 73.3 21.4 1.5 22.9 < LOQ < LOQ < LOQ < LOQ < LOQ < LOQ 0.9 0.8 1.7 

1 44.6 3.4 48.0 40.4 6.9 47.3 0.9 < LOQ 0.9 < LOQ < LOQ < LOQ 0.5 1.7 2.2 3 6.3 1.9 8.2 62.9 13.4 76.3 13.5 < LOQ 13.5 < LOQ < LOQ < LOQ 0.9 0.6 1.5 7 < LOQ < LOQ < LOQ 77.4 20.5 97.9 < LOQ < LOQ < LOQ < LOQ < LOQ < LOQ 1.1 0.4 1.5 

14 < LOQ < LOQ < LOQ 68.2 27.2 95.4 < LOQ < LOQ < LOQ < LOQ < LOQ < LOQ 0.9 0.1 1.0 30 < LOQ < LOQ < LOQ 23.3 34.1 57.4 3.1 2.8 5.9 < LOQ < LOQ < LOQ 0.4 1.3 1.7 60 < LOQ < LOQ < LOQ 19.8 32.0 51.8 3.3 2.2 5.5 2.1 < LOQ 2.1 4.1 0.7 4.8 91 < LOQ < LOQ < LOQ 13.4 15.5 28.9 3.3 12.9 16.2 2.0 1.0 3.0 4.0 4.1 8.1 

[3-14C] 

120 < LOQ < LOQ < LOQ < LOQ 21.0 21.0 17.4 12.8 30.2 < LOQ < LOQ < LOQ 0.3 1.0 1.3 

0 77.0 1.5 78.5 17.5 < LOQ 17.5 < LOQ < LOQ < LOQ < LOQ < LOQ < LOQ 0.4 0.2 0.6 

0.2 73.3 3.3 76.6 20.0 1.7 21.7 < LOQ < LOQ < LOQ < LOQ < LOQ < LOQ 1.0 0.9 1.9 

1 41.4 2.9 44.3 44.9 6.6 51.5 0.7 < LOQ 0.7 < LOQ < LOQ < LOQ 0.6 1.5 2.1 3 6.5 1.6 8.1 61.3 12.1 73.4 13.5 < LOQ 13.5 < LOQ < LOQ < LOQ 2.7 0.4 3.1 7 < LOQ < LOQ < LOQ 75.3 21.8 97.1 < LOQ < LOQ < LOQ < LOQ < LOQ < LOQ 0.8 0.5 1.3 

14 < LOQ < LOQ < LOQ 69.2 29.8 99.0 1.0 < LOQ 1.0 < LOQ < LOQ < LOQ 0.5 0.1 0.6 30 < LOQ < LOQ < LOQ 19.7 36.4 56.1 3.7 3.5 7.2 < LOQ < LOQ < LOQ 0.9 1.6 2.5 60 < LOQ < LOQ < LOQ 6.4 41.2 47.6 6.0 7.7 13.7 < LOQ < LOQ < LOQ 0.5 1.1 1.6 91 < LOQ < LOQ < LOQ < LOQ 29.0 29.0 3.9 13.6 17.5 1.4 < LOQ 1.4 2.3 0.8 3.1 

[5-14C] 

120 < LOQ < LOQ < LOQ < LOQ < LOQ < LOQ 8.0 42.8 50.8 < LOQ < LOQ < LOQ 0.2 1.2 1.4 

LOQ denotes limit of quantification (i.e. approx. 0.5 – 0.8 % of AR) 
– 177 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.4.4.3-5: Characterization of extractable radioactivity [% of AR] after application of [3-14C] or [5-14C] labelled spirotetramat (288 g ai ha-1) to the 

aerobic water/sediment system ‘Anglerweiher’. 

Spirotetramat Spirotetramat- enol Spirotetramat- ketohydroxy Spirotetramat- MA-amide Spirotetramat- oxo-enol isomer Spirotetramat- di-hydroxy Unidentified RA Label DAT 

Wat. Sed. Total Wat. Sed. Total Wat. Sed. Total Wat. Sed. Total Wat. Sed. Total Wat. Sed. Total Wat. Sed. Total 

0 70.2 1.4 71.6 24.3 < LQ 24.3 < LQ < LQ < LQ < LQ < LQ < LQ < LQ < LQ < LQ < LQ < LQ < LQ 1.0 0.2 1.2 

0.2 60.7 2.8 63.5 32.0 1.2 33.2 < LQ < LQ < LQ < LQ < LQ < LQ < LQ < LQ < LQ < LQ < LQ < LQ 0.6 0.5 1.1 

1 38.9 2.0 40.9 50.7 5.9 56.6 0.8 < LQ 0.8 < LQ < LQ < LQ < LQ < LQ < LQ < LQ < LQ < LQ 0.1 1.4 1.5 3 5.8 0.6 6.4 78.7 7.3 86.0 2.4 0.5 2.9 < LQ < LQ < LQ < LQ < LQ < LQ < LQ < LQ < LQ 1.2 2.2 3.4 7 < LQ < LQ < LQ 79.7 11.3 91.0 3.4 1.0 4.4 < LQ < LQ < LQ < LQ < LQ < LQ < LQ < LQ < LQ 0.3 2.7 3.0 

14 < LQ < LQ < LQ 72.5 15.7 88.2 2.6 1.8 4.4 1.6 < LQ 1.6 < LQ < LQ < LQ < LQ < LQ < LQ 2.5 0.5 3.0 30 < LQ < LQ < LQ 39.9 13.4 53.3 6.2 11.9 18.1 2.4 < LQ 2.4 < LQ < LQ < LQ < LQ < LQ < LQ 0.7 1.5 2.2 60 < LQ < LQ < LQ 15.1 2.2 17.3 6.7 18.8 25.5 7.8 1.4 9.2 < LQ < LQ < LQ < LQ 1.2 1.2 4.7 0.7 5.4 91 < LQ < LQ < LQ 6.3 < LQ 6.3 1.8 13.8 15.6 6.3 < LQ 6.3 3.7 < LQ 3.7 4.3 5.5 9.8 4.9 2.0 6.9 

[3-14C] 

120 < LQ < LQ < LQ 8.2 6.4 14.6 5.6 11.3 16.9 < LQ < LQ < LQ 6.0 < LQ 6.0 < LQ < LQ < LQ 0.4 3.1 3.5 

0 71.2 1.7 72.9 25.7 < LQ 25.7 < LQ < LQ < LQ < LQ < LQ < LQ < LQ < LQ < LQ < LQ < LQ < LQ 0.6 0.2 0.8 

0.2 64.9 2.1 67.0 29.2 2.1 31.3 < LQ < LQ < LQ < LQ < LQ < LQ < LQ < LQ < LQ < LQ < LQ < LQ 0.7 0.4 1.1 

1 39.9 2.0 41.9 46.0 5.4 51.4 2.0 0.5 2.5 < LQ < LQ < LQ < LQ < LQ < LQ < LQ < LQ < LQ 1.5 1.5 3.0 3 5.4 0.6 6 78.6 7.1 85.7 2.0 0.5 2.5 < LQ < LQ < LQ < LQ < LQ < LQ < LQ < LQ < LQ 1.2 1.9 3.1 7 < LQ < LQ < LQ 77.9 14.2 92.1 2.2 < LQ 2.2 < LQ < LQ < LQ < LQ < LQ < LQ < LQ < LQ < LQ 0.8 1.6 2.4 

14 < LQ < LQ < LQ 71.5 14.6 86.1 3.1 2.9 6.0 1.6 < LQ 1.6 < LQ < LQ < LQ < LQ < LQ < LQ 1.0 0.6 1.6 30 < LQ < LQ < LQ 39.7 15.5 55.2 6.7 8.6 15.3 2.1 < LQ 2.1 < LQ < LQ < LQ < LQ < LQ < LQ 3.1 3.6 6.7 60 < LQ < LQ < LQ 15.0 4.1 19.1 5.7 23.1 28.8 6.1 2.1 8.2 < LQ < LQ < LQ 4.2 2.5 6.7 0.2 1.5 1.7 91 < LQ < LQ < LQ 7.9 4.7 12.6 2.1 23.9 26.0 3.6 1.9 5.5 3.8 < LQ 3.8 < LQ 2.1 2.1 6.6 0.6 7.2 

[5-14C] 

120 < LQ < LQ < LQ 8.0 < LQ 8.0 2.4 31.4 33.8 2.0 < LQ 2.0 < LQ 2.3 2.3 < LQ < LQ < LQ 4.8 0.5 5.3 

LQ denotes limit of quantification (i.e. approx. 0.5 – 0.8 % of AR) 
– 178 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.4.4.3-6: Calculated half-lives [days] of spirotetramat in the aerobic water/sediment systems

‘Hönniger Weiher’ and ‘Anglerweiher’ based on SFO kinetics. 

Water Total system 

Dissipation Degradation System Label 

DT50

[days] 

DT90

[days] R

2 DT50

[days] 

DT90

[days] R

2

Kinetics 

‘Hönniger Weiher’ Labels used as replicates 1.00 3.31 0.99 1.06 3.52 1.00 SFO 

‘Anglerweiher’ Labels used as replicates 1.02 3.40 0.99 1.05 3.50 0.99 SFO 

Conclusion:

Spirotetramat quickly degraded in two contrasting aerobic water/sediment systems with a degradation halflife in the entire system of 1.0 day (both systems, SFO, R2

≥ 0.99). Dissipation from the water layer was fast 

as well. No distinct differences between labels used were observed. As major metabolites spirotetramat-enol 

(maximum in the total system 99.0 % of AR by 14 DAT, decreasing thereafter) and spirotetramatketohydroxy (maximum in the total system 50.8 % of AR at study termination) were observed. Other 

identified substances (spirotetramat-MA-amide, spirotetramat-oxo-enol isomer and spirotetramat-di-hydroxy) 

did not exceed 9.8 % of AR in the total system individually, non identified radioactivity accounted for 

maximum of 8.1 % of AR in sum. Formation of 14CO2 (maximum 24.0 % of AR in one system by study 

termination) indicate significant mineralization of the test item, NER accounted for maximum 40.7 % of AR by 

91 DAT. 

Reviewer comments:

• Dissipation and degradation rates of spirotetramat, spirotetramat-enol and spirotetramat-ketohydroxy 

were (re-)calculated by the notifier (supplemental studies, Röpke, 2006b). 

Reference: BYI08330[azaspirodecenyl-3-14C]: Anaerobic aquatic metabolism 

Author(s), year: Shepherd, J., Arthur, E. L., Dominic, A., 2005 

Study/report number: M-261943-01-1, MEFNX015 

Guideline(s): US-EPA N 162-3 (1982, 1989), OECD Guideline 308 (2002), Canada PMRA 

DACO Number 8.2.3.5.6 (1987) 

GLP: Yes 

Deviations: None 

Validity: Study considered acceptable 

Material and methods:

Test substances: [Azaspirodecenyl-3-14C]-spirotetramat, 3.67 MBq mg-1, > 99 % radiochemical 

purity (HPLC), batch BECH 0936 

Reference substances: Spirotetramat, spirotetramat-enol (both 3-14C labelled) 

Application rate: 14 μg L-1 (assuming 288 g ai ha-1 and 200 cm water depth), 10fold concentration 

used for metabolite identification work 

Co-solvent: Acetonitrile (< 0.1 %, v/v) 

Incubation set-up: 50 g (dry weight) sediment (2 mm sieved), 150 mL of pond water, sediment/water 

ratio 1/3 (w/w) 

Acclimatization period: 27 days 

Test duration: 120 days 

Incubation conditions: 20 ± 1 °C in darkness with a N2-atmosphere 

Volatile traps: 2 × 2.0 M KOH (30 ml), ethylene glycol (30 ml), 1 M sulphuric acid (30 ml) 

Monitoring: pH, O2, redox potential 

Analysis: The water phase was acidified with formic acid, radio-assayed by LSC and 

concentrated by rotary evaporation. 
– 179 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

The sediment phase was extracted once with 100 ml of acetonitrile/water/formic 

acid (90/10/0.1, v/v/v) following ASE extraction at 80 °C using the same solvent. 

The two extracts were combined, acidified and radio-assayed by LSC. An aliquot 

was concentrated by rotary evaporation and analysed by HPLC.

Non extractable residues were radio-assayed by combustion LSC. 

Analytical techniques: LSC, HPLC-RAD, LC-ESI/MS 

Kinetic evaluation: Simple first order (SFO) kinetics, GraphPad PRISM 

Table B.8.4.4.3-7: Physicochemical characteristics of the water/sediment matrix. 

Name ‘Lawrence’ 

Geographic location Nelson Environmental Study Area, Lawrence, KS, 

Jefferson County, USA 

Texture (USDA) Clay loam 

Sand (USDA) [%] 21 

Silt (USDA) [%] 40 

Clay (USDA) [%] 39 

pH (0.01 M CaCl2) 7.1 

pH (water) 7.6 

pH (saturated paste) 7.4 

Redox potential [mV] – start / 120 DAT 68.5 / -38.5 

Organic C [%] 0.7 

CEC [meq kg-1] 327 

Field MC at 0.33 bar [%] 35.8 

Bulk density [g cm-3] 1.1 

Sediment 

Microbial biomass [108 cells g-1] – start / 120 DAT 2.00 / 1.07 

pH 7.5 

Total hardness (CaCO3) [mg L-1] 139 

Oxygen content [mg L-1] – start / 120 DAT 0.0 / 0.0 

Redox potential [mV] – start / 120 DAT 55.2 / -20.0 

DOC [mg L-1] – start / 120 DAT 8.4 / 9.3 

Water 

Microbial biomass [106 cells g-1] – start / 120 DAT 3.48 / 2.55 

Findings:

Throughout the study, the average redox potential (+25 mV in water, +15 mV in sediment) and the average 

dissolved oxygen concentration (≤ 0.1 mg L-1) remained low indicating that an anaerobic reducing 

environment had been maintained. The average pH of the water ranged from 6.7 to 7.3. 

The mean material balance for the study ranged from 90.1 to 102.2 % of AR. 

The concentration of spirotetramat in water decreased from 81.3 % of AR by 0 DAT to 57.2 % of AR by 2 

DAT and continued to decrease to 0.0 % of AR by 14 DAT. In the sediment the concentration of 

spirotetramat decreased from 8.8 % of AR by 0 DAT to 0.0 % of AR by 14 DAT. The only transformation 

product detected in water was spirotetramat-enol with a maximum concentration of 80.5 % of AR by 14 DAT, 

hardly decreasing thereafter to a final amount of 73.3 % of AR. In the sediment spirotetramat-enol was

detected with a maximum amount of 28.5 % of AR by 21 DAT without significant changes towards the further 

incubation. No other metabolites were observed in the water or in the sediment phase. 
– 180 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.4.4.3-8: Distribution and recovery of radioactivity [% of AR] after application of [3-14C] 

labelled spirotetramat (288 g ai ha-1) to the anaerobic water/sediment system ‘Lawrence’ (mean of 

duplicate samples). 

Label DAT 14CO2

Organic 

volatiles Water Sediment NER Total 

0 0.0 0.0 81.3 8.8 0.0 90.1 

2 0.6 0.0 79.8 17.7 0.0 98.1 

7 0.5 0.0 76.6 21.2 0.0 98.3 

9 0.6 0.0 77.2 22.3 0.0 100.1 

14 0.6 0.0 80.2 21.4 0.0 102.2 

21 0.6 0.0 75.7 25.5 0.0 101.8 

28 0.7 0.0 76.4 24.1 0.0 101.3 

63 0.7 0.0 72.3 28.0 0.0 101.0 

90 0.7 0.0 76.4 24.0 0.5 101.5 

[3-14C] 

120 0.8 0.0 73.3 26.7 0.6 101.4 

Table B.8.4.4.3-9: Characterization of extractable radioactivity [% of AR] after application of [3-14C] 

labelled spirotetramat (288 g ai ha-1) to the anaerobic water/sediment system ‘Lawrence’. 

Spirotetramat Spirotetramat-enol Label DAT 

Water Sediment Total Water Sediment Total 

0 83.3 9.3 92.6 0.0 0.0 0.0 

0 79.3 8.2 87.5 0.0 0.0 0.0 

2 53.1 7.2 60.3 26.6 10.2 36.8 

2 61.4 7.1 68.5 18.5 10.9 29.4 

7 11.0 2.2 13.2 64.2 19.1 83.3 

7 8.8 0.0 8.8 69.2 21.1 90.3 

9 9.1 2.2 11.3 67.9 19.3 87.2 

9 6.4 0.0 6.4 70.8 23.1 93.9 

14 0.0 0.0 0.0 80.5 20.9 101.4 

14 0.0 0.0 0.0 79.8 21.1 100.9 

21 0.0 0.0 0.0 78.2 22.6 100.8 

21 0.0 0.0 0.0 73.1 28.5 101.6 

28 0.0 0.0 0.0 77.0 23.1 100.1 

28 0.0 0.0 0.0 75.9 25.0 100.9 

63 0.0 0.0 0.0 72.5 27.8 100.3 

63 0.0 0.0 0.0 72.1 28.2 100.3 

90 0.0 0.0 0.0 76.2 24.0 100.2 

90 0.0 0.0 0.0 76.5 23.9 100.4 

120 0.0 0.0 0.0 74.9 25.0 99.9 

[3-14C] 

120 0.0 0.0 0.0 71.7 28.4 100.1 

Table B.8.4.4.3-10: Calculated half-lives of [3-14C] [days] labelled spirotetramat in the anaerobic 

water/sediment system ‘Lawrence’ based on SFO kinetics. 

Water Total system 

Dissipation Degradation System 

DT50

[days] 

DT90

[days] R

2 DT50

[days] 

DT90

[days] R

2

Kinetics 

‘Lawrence’ 2.8 9.2 0.99 2.8 9.3 0.99 SFO 

Conclusion:

Under anaerobic water/sediment conditions spirotetramat was completely transformed into its major 

metabolite spirotetramat-enol which can be considered stable under the experimental conditions. 

Spirotetramat-enol reached maximum amounts in the water of 80.5 % of AR by 14 DAT and in the sediment 
– 181 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

of 28.5 % of AR by 21 DAT hardly changing thereafter. The degradation half-life of spirotetramat was 

calculated to be 2.8 days (R2

 = 0.99) in the total system, respective DT90 was 9.3 days. 

Reviewer comments:

None 

B.8.4.4.4 Supplemental studies 

Reference: Kinetic Evaluation of the Aerobic Aquatic metabolism of BYI08330, 

BYI08330-enol and BYI08330-ketohydroxy in water sediment systems 

Author(s), year: Röpke, B., 2006b 

Study/Report number: M-277415-01-1, MEF-06/279 

Guideline(s): Recommendations of FOCUS working group on degradation kinetics (FOCUS, 

2006) 

GLP: Not applicable 

Deviations: Not applicable 

Validity: Study considered acceptable 

Material and methods:

The behaviour of spirotetramat and its major water/sediment metabolites spirotetramat-enol and 

spirotetramat-ketohydroxy in an aquatic environment was investigated by kinetic evaluation of the aerobic 

water/sediment studies conducted with the two test systems ‘Hönniger Weiher’ and ‘Anglerweiher’. 

Simple first order (SFO) dissipation half-life of spirotetramat in the water phase is based on SFO kinetics. 

Additionally, overall SFO degradation of spirotetramat and spirotetramat-enol and spirotetramat-ketohydroxy 

in the entire system were derived using a four-compartment model (no additional pathways to sink). 

Figure B.8.4.4.4-1: Multi-compartment model used for fitting residues of spirotetramat and 

metabolites in water/sediment studies (entire system). 

The goodness of fit was assessed by visual inspection, R2

, χ

2

 error and t-test statistics. Calculations were 

performed with MatLab 7.0.4.365 (MatLab, 2005). Different equations were integrated by a Runge-Kutta 

method, and the Levenberg-Marquardt algorithm was used for non-linear parameter optimisation. 

Spirotetramat (SFO) 

Spirotetramat-enol (SFO) 

Spirotetramat-ketohydroxy (SFO) 

Sink 
– 182 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

In case of spirotetramat-ketohydroxy, the 3 DAT sampling of ‘Hönninger Weiher’ was considered an outlier, 

amounts of spirotetramat-ketohydroxy were set to < LOQ. 

Findings:

Table B.8.4.4.4-1: Calculated dissipation (water phase) and degradation (entire system) half-life of 

spirotetramat and the metabolites spirotetramat-enol and spirotetramat-ketohydroxy in two aerobic 

water/sediment systems based on SFO kinetics (both labels handled as replicates). 

Substance Compartment Test system DT50

[days] 

DT90

[days] R

2

χ

2

error 

[%] 

Kinetics 

Water ‘Hönniger Weiher’ 0.82 2.73 0.99 6.9 SFO a

(Dissipation) ‘Anglerweiher’ 0.74 2.45 0.97 12.3 SFO 

‘Hönniger Weiher’ 0.86 2.85 0.99 6.2 SFO 

Spirotetramat 

Entire system 

(Degradation) ‘Anglerweiher’ 0.70 2.34 0.97 11.9 SFO 

Spirotetramat- ‘Hönniger Weiher’ 59.0 196 0.93 13.4 PSFO  MSFO

enol 

Entire system 

 (Degradation) ‘Anglerweiher’ 37.9 126 0.93 15.6 PSFO  MSFO

Spirotetramat- ‘Hönniger Weiher’ Not evaluable, no decline PSFO  M1SFO M2SFO

ketohydroxy 

Entire system 

 (Degradation) ‘Anglerweiher’ Not evaluable, no decline PSFO  M1SFO M2SFO

a

 Re-calculated by the reviewer (see comments) 

Conclusion:

Degradation of spirotetramat in the entire system was calculated to be 0.86 and 0.70 days for the ‘Hönniger 

Weiher’ and ‘Anglerweiher’ test system, respectively (following SFO kinetics, R2

≥ 0.97, χ

2

≤ 6.9). Based on 

multi-compartment modelling, metabolite spirotetramat-enol degraded with a DT50 in the range of 37.9 – 59.0 

days in the total system (all SFO, R2 > 0.93). Metabolite spirotetramat-ketohydroxy was considered to be 

stable in both systems. 

Reviewer comments:

• The multi-compartment model used by the notifier did not include supplemental pathways from the 

parent and the metabolite spirotetramat-enol to the sink. Additional calculations by the reviewer 

including these supplemental pathways did not improve the model. Owing to the extensive formation 

of spirotetramat-enol from the parent, no additional pathway (e.g. from parent to sink) has to be 

assumed. Therefore, the multi-compartment model used by the notifier is considered appropriate. 

• For both metabolites, additional calculations are presented for the dissipation in the water and 

sediment based on the maximum occurrence as starting point (following SFO kinetics). Since the 

aquatic risk assessment of both metabolites is solely based on the degradation half-life in the total 

system, these data are not considered relevant (not presented her). 

• For calculating the dissipation of spirotetramat in the water system, 0 DAT amounts of metabolites 

were not added to the measured 0 DAT amounts of spirotetramat (as done for the entire system). 

Therefore, dissipation in the water phase was re-calculated by the reviewer following current 

guidance (SANCO/10058/2005, vers. 1.0, 2005). 
– 183 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

B.8.4.4.5 Summary on fate & behaviour in aquatic systems 

Aquatic hydrolysis 

One hydrolysis study in dark sterile buffer solutions at pH 4, 7 and 9 at 20 °C (30 days), 25°C (up to 31 days) 

and 50 °C (up to 48 days) using [3-14C] and [5-14C] labelled spirotetramat was carried out. Spirotetramat was 

shown to hydrolyse in strong dependence of the pH value and temperature, DegT50 values at 25 °C were 

32.5, 8.6 and 0.32 days at pH 4, 7 and 9, respectively. Hydrolysis rates decreased with decreasing 

temperature. No significant differences between labels used were observed. No volatiles were formed. 

During hydrolysis, spirotetramat almost exclusively degraded to spirotetramat-enol, which was shown to be 

stable under conditions of sterile hydrolysis in a separate hydrolysis study (at pH 4, 7 and 9, 25 and 50 °C, 

using [3-14C] and [5-14C] labelled spirotetramat-enol). 

NH

O

O

O

O O

H

NH

O

HO

O

H

Spirotetramat Spirotetramat-enol

Figure B.8.4.4.5-1: Proposed hydrolysis pathway of spirotetramat in sterile buffer solutions. 

Aquatic photolysis 

Aquatic photolysis of spirotetramat was investigated in sterile buffer solutions at pH 5.0 and in sterilized 

natural water at pH 7.9 using [3-14C] and [5-14C] labelled parent. The test systems were continuously 

irradiated with a xenon arc lamp (> 290 nm) for 7 days and 10 days (sterile buffer solution and natural water, 

respectively) to simulate the impact of natural light. Both experiments were carried out at 25 °C. 

Under irradiation in sterile buffer solutions at pH 5.0, spirotetramat degraded with a half-life of 2.7 days 

(following SFO kinetics, R2 = 0.98, net photolysis half-life corrected for hydrolysis was 3.0 days). The 

experimental half-life (including photolysis and hydrolysis) corresponds to 12.0, 9.3 and 11.4 days under 

environmental midday summer light in Athens (Greece, EU), Phoenix (AZ, USA) and Edmonton (Alberta, 

Canada). In the dark control, DegT50 was 26.2 days (owing to hydrolysis, only) indicating that 

photodegradation of spirotetramat can be considered a significant route for the elimination of the compound 

from the environment. 

In the sterile buffer solutions at pH 5.0, spirotetramat was transformed to the major metabolites 

spirotetramat-photo-cyclopentyl, spirotetramat-photo-hydroxymethyl, spirotetramat-photo-formyl and 

spirotetramat-photomethyl carbonate (all these metabolites are considered photo-rearrangement products). 

Maximum amounts formed were 42.9 %, 22.9 %, 11.5 % and 19.3 % of AR, respectively. Under dark 

conditions only the common hydrolysis product spirotetramat-enol was observed. As demonstrated in a 

separate study (see following text), formation of these photo-rearrangement products, which has to be 

attributed to the highly artificial experimental conditions, was not observed in sterilized natural water at a pH 

of 7.9. 
– 184 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

NH

O

O

O

O O

H

Spirotetramat

NH

O

O

H

HO

Spirotetramat-photocyclopentyl

Spirotetramat-photo2-methylcarbonate

O

O

O

NH

O

O

H

NH

O

O

H

HO

Spirotetramat-photo2-hydroxy-methyl

NH

O

O

H

O

Spirotetramat-photo2-formyl

CO2

Figure B.8.4.4.5-2: Proposed photolysis pathway of spirotetramat in sterile buffer solution (pH 5.0). 

Under irradiation in sterilized natural water and pH 7.9, spirotetramat extensively degraded with a half-life of 

0.19 days (following SFO kinetics, R2 = 1.00, net photolysis half-life corrected for hydrolysis was 0.22 days). 

The experimental half-life (including photolysis and hydrolysis) corresponds to 0.66, 0.50 and 0.62 days 

under environmental midday summer light in Athens (Greece, EU), Phoenix (AZ, USA) and Edmonton 

(Alberta, Canada). In the dark control DegT50 was 1.5 days (owing to hydrolysis, only) indicating that 

photodegradation of spirotetramat can be also considered a significant route for the elimination of the 

compound from the environment under more alkaline conditions. 

Two major phototransformation products were formed besides the common hydrolysis product spirotetramatenol: methoxy-cyclohexyl-aminocarboxylic acid (maximum 11.3 % of AR at study termination) and methoxycyclohexanone (17.5 % of AR), the latter a photolysis metabolite also observed in soil photolysis. No photorearrangement products were formed. Under dark conditions only spirotetramat-enol was formed owing to 

hydrolysis. 

The photolysis study in sterile natural water was conducted to demonstrate that photo-rearrangement 

products observed under photolysis in sterile buffer solution at pH 5 (Stupp, 2005a) are not likely to occur 

under more natural conditions. However, based on the contrasting pH value of both photolysis studies (pH 

5.0 in sterile buffer solution vs. pH 7.9 in sterile natural water) no final conclusion on the occurrence of photorearrangement product in sterilized natural water in more acidic surface water can be drawn from the study 

results per se. However, based on the rapid degradation half-life (dark rate) of spirotetramat in 

water/sediment systems (pH 6.7 and 7.2) of approx. 0.8 days (Menke, 2006c, Röpke, 2006b) a significant
– 185 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

formation of photo-rearrangement products as observed in Stupp (2005a), in which spirotetramat showed a 

dark hydrolysis rate of 26.2 days, is highly unlikely to occur. Therefore, photo-rearrangement products 

observed in sterile buffer solutions at pH 5 are not considered relevant for further risk assessment. 

NH

O

O

O

O O

H

NH

O

HO

O

H

Spirotetramat Spirotetramat-enol

O

H

O NH2

HO

O

H

O

Methoxy-cyclohexanone Methoxy-cyclohexylamino 

carboxylic acid

Figure B.8.4.4.5-3: Proposed photolysis pathway of spirotetramat in sterile natural water (pH 7.9). 

In two separate studies, the quantum yields of the direct photochemical degradation of spirotetramat and 

spirotetramat-enol were investigated. These studies were carried out in sterile, unbuffered water (no pH 

measured) at a test concentration of 5 mg L-1 using a mercury immersion lamp TQ 150 (> 295 nm) and a 

uranyl oxalate actinometer. Mean degradation half lives under these experimental conditions were 0.15 days 

(spirotetramat) and 1.39 days (spirotetramat-enol). No dark control samples were investigated to account for 

hydrolysis processes. However, owing to the short exposure time of the test solution (4 hrs) no significant 

degradation of spirotetramat owing to hydrolysis is expected. Spirotetramat-enol was shown to be 

hydrolytically stable from pH 4 – 9. Quantum yield for spirotetramat and spirotetramat-enol were calculated 

to be 0.00571 and 0.000252, respectively. Based on different arithmetic models (GC-SOLAR and Frank & 

Klöpffer) by means of resulting quantum yield and adsorption, environmental direct phototransformation halflives of spirotetramat and spirotetramat-enol, in a range of approx. 0.5 – 1 days and 9 – 16 days, 

respectively, can be assessed for the period of main use (late spring to summer). 

Biological degradation 

Results of a readily biodegradability study indicate that spirotetramat is not readily biodegradable. 

Dark aerobic water/sediment studies were conducted with two contrasting (pH, texture) natural systems, 

‘Hönniger Weiher’ and ‘Anglerweiher’, using [3-14C] and [5-14C] labelled spirotetramat. The ‘Hönniger Weiher’ 

test system represents a loam sediment with an organic carbon content of 4.4 %, a microbial activity of 

36 mg CO2 h-1 kg-1 and a pH of 5.6 (CaCl2). The ‘Anglerweiher’ test system is characterized by a loamy sand 

sediment with a pH of 6.8 (CaCl2), with an organic carbon content of 0.99 % and a lower microbial activity 

(10 mg CO2 h-1 kg-1). In both systems, water and sediment stayed aerobically throughout the test period. 

Mineralization of spirotetramat to 14CO2 was low in the ‘Hönniger Weiher’ test system, accounting for 11.0 % 

and 5.9 % of AR by study termination (120 DAT) using [3-14C] and [5-14C] labelled parent, respectively. 

Formation of 14CO2 from [5-14C] labelled spirotetramat was approx. half indicating that this part of the 

molecule is less accessible to biodegradation than the [3-14C] position. Formation of 14CO2 was higher in the 
– 186 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

‘Anglerweiher’ test system accounting for 24.0 % and 13.5 % of AR using [3-14C] and [5-14C] labelled parent, 

respectively. 

Maximum formation of NER (mean value of both labels) accounted for 36.4 % and 33.1 % of AR in the 

‘Hönniger Weiher’ and Anglerweiher’, respectively. In the first test system, maximum of NER formation was 

observed by study termination (120 days), in the latter system, maximum formation of NER was found by 91 

DAT, slightly decreasing thereafter to 34.6 % of AR by study termination (120 days). Differences between 

labels used were small in case of the ‘Hönninger Weiher’ and insignificant in case of the ‘Angler Weiher’. 

In the total system, a rapid decline of spirotetramat was observed with DegT50 of 0.9 and 0.7 days in the 

‘Hönninger Weiher’ and ‘Anglerweiher’ test system (following SFO kinetics), respective DegT90 values were 

2.9 and 2.3 days. Dissipation in the water phase was calculated to be 0.8 and 0.7 in the ‘Hönninger Weiher’ 

and ‘Anglerweiher’ test system. No distinct differences between labels used were observed. 

Spirotetramat-enol (maximum in the entire system 99.0 % of AR by 14 DAT, decreasing thereafter) and 

spirotetramat-ketohydroxy (maximum in the total system 50.8 % of AR at study termination) were observed 

as major (> 10 % of AR) metabolites. Based on multi-compartment modelling, spirotetramat-enol degraded

with a mean DegT50 of 47.3 days in the entire system (SFO kinetics, R2

 > 0.93). In comparison to soil 

systems, degradation of spirotetramat-enol is distinct slower in aquatic systems. In contrast to the soil (which 

is considered a triphasic system of soil, water and air), the water/sediment is just bi-phasic (suspended 

sediments and water containing more or less dissolved oxygen). Since the main path of spirotetramat-enol 

degradation in soil is a surface catalyzed oxidation, it is reasonable that a significantly lower overall 

degradation in water/sediment system occurs (spirotetramat-enol is stable under conditions of sterile 

hydrolysis). This assumption is strongly supported by the anaerobic water/sediment study were 

spirotetramat-enol was observed to be stable at all. 

The major water/sediment metabolite spirotetramat-ketohydroxy was considered to be stable in both 

systems. 

Both metabolites, spirotetramat-enol and spirotetramat-ketohydroxy, were also shown to significantly 

dissipate into the sediment phase with a maximum occurrence of 36.6 % (by 60 DAT) and 27.8 % of AR (by

study termination), respectively. 

Other identified substances (spirotetramat-MA-amide, spirotetramat-oxo-enol isomer and spirotetramat-dihydroxy) did not exceed 9.8 % of AR in the total system individually, non identified radioactivity accounted for 

maximum of 8.1 % of AR in sum. 
– 187 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

NH

O

O

O

O O

H

NH

O

HO

O

H

Spirotetramat Spirotetramat-enol

NH

O

O

O

H

OH

Spirotetramat-ketohydroxy

NH

O

O

H

OH

HO

O

Spirotetramat-MA-amide

NH

O

HO

O

H

OH

Spirotetramat-dihydroxy

NH

O

HO

Spirotetramat-oxo-enol isomer

O

CO2 NER

Figure B.8.4.4.5-4: Proposed degradation pathway of spirotetramat in aerobic water/sediment 

systems (metabolites > 10 % of AR are indicated in bold). 

One dark anaerobic water/sediment study is available, conducted with a test system (‘Lawrence’) 

characterized by a clay loam sediment with a pH of 7.1 (CaCl2) and an organic C content of 0.7 %. 

Anaerobic conditions in the water and in the sediment were maintained throughout the study. 

Under anaerobic water/sediment conditions spirotetramat was completely transformed into its major 

metabolite spirotetramat-enol which can be considered stable under the experimental conditions. 

Spirotetramat-enol reached maximum amounts in the water of 80.5 % of AR by 14 DAT and in the sediment 

of 28.5 % of AR by 21 DAT hardly changing thereafter. The degradation half-life of spirotetramat was 

calculated to be 2.8 days (R2

 = 0.99) in the entire system, respective DegT90 was 9.3 days. 
– 188 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.4.4.5-1: Summary on DT50 and DT90 [days] for the dissipation and degradation of 

spirotetramat, spirotetramat-enol and spirotetramat-ketohydroxy in aerobic water/sediment studies. 

Water Sediment Total system 

Compound Test system Degradation Dissipation Degradation Degradation 

DegT50 DegT90 DT50 DT90 DegT50 DegT90 DegT50 DegT90

‘Hönninger Weiher’ nc nc 0.82 2.73 nc nc 0.86 2.85 

Spirotetramat Angler Weiher’ nc nc 0.74 2.45 nc nc 0.70 2.34 

Geometric mean nc nc 0.78 2.59 nc nc 0.78 2.58 

‘Hönninger Weiher’ nc nc nc nc nc nc 59.0 196 

Angler Weiher’ nc nc nc nc nc nc 37.9 126 Spirotetramatenol 

Geometric mean nc nc nc nc nc nc 47.3 157 

‘Hönninger Weiher’ nc nc nc nc nc nc Stable Stable 

Angler Weiher’ nc nc nc nc nc nc Stable Stable Spirotetramatketohydroxy 

Geometric mean nc nc nc nc nc nc Stable Stable 

nc denotes not calculated 

Table B.8.4.4.5-2: Summary on DT50 and DT90 [days] for the dissipation and degradation of 

spirotetramat, spirotetramat-enol in anaerobic water/sediment studies. 

Water Sediment Total system 

Compound Degradation Dissipation Degradation Degradation Test 

system 

DegT50 DegT90 DT50 DT90 DegT50 DegT90 DegT50 DegT90

Spirotetramat ‘Lawrence’ nc nc 2.8 9.2 nc nc 2.8 9.3 

Spirotetramat-enol ‘Lawrence’ nc nc nc nc nc nc Stable Stable 

nc denotes not calculated 

Table B.8.4.4.5-3: Summary on maximum occurrence [% of AR] of spirotetramat and metabolites in 

aerobic water/sediment studies (mean of labels used, data stated in brackets give day of maximum 

occurrence). 

Compound Water Sediment Total 

Spirotetramat - 3.2 (1) - 

Spirotetramat-enol 78.8 (7) 36.6 (60) 97.5 (7) 

Spirotetramat-ketohydroxy 12.7 (120) 27.8 (120) 40.5 (120) 

Spirotetramat-MA-amide 7.0 (60) 1.8 (60) 8.7 (60) 

Spirotetramat-oxo-enol isomer 3.8 (91) 1.2 (120) 4.2 (120) 

Spirotetramat-di-hydroxy 2.2 (91) 3.8 (91) 6.0 (91) 

B.8.4.5 Degradation in the saturated zone (OECD Annex IIA, 7.9) 

The degradation behaviour of spirotetramat in the saturated zone has not been investigated in specific

studies since it is not expected to reach such zones after its use according to good agricultural practices. If at 

all needed it can be estimated from laboratory soil degradation studies as well as from the laboratory

water/sediment studies performed under dark aerobic and anaerobic conditions. In these studies 

degradation of spirotetramat and its residues was comparatively fast. 
– 189 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

B.8.5 Impact on water treatment procedures (OECD Annex IIIA, 9.6.4) 

In the readily biodegradability study, the test showed that spirotetramat had no inhibitory effect on microbial 

activity in an activated sludge media. Furthermore, the activated sludge respiration test gave a spirotetramat 

3-hrs-EC50 of > 10 000 mg L-1. Results of modelling indicate that maximum predicted concentrations of 

spirotetramat in surface water will not exceed 5.9 μg L-1, indicating a large margin of safety. The 

concentration in groundwater does not exceed the maximum acceptable concentration of 0.1 μg L-1. It can 

therefore be concluded that spirotetramat is unlikely to impact adversely onto water treatment procedures. 
– 190 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

B.8.6 Predicted environmental concentration in ground water for the active substance and 

metabolites (PECGW) (OECD Annex AIII, 9.6) 

The risk assessment for the EU can be found in the APPENDIX.

The risk assessment for the PMRA and the US-EPA is not included in this monograph. 

The Proposed Registration Decision – Spirotetramat (PRD2008-07), containing the detailed Canadian 

review and risk assessment, has been published by the PMRA and can be found at the PMRA’s web site 

www.pmra-arla.gc.ca. 

The registration decision made by the U.S. EPA's Office of Pesticide Program is supported by the risk 

assessments found at our Federal Docket website located at: 

http://www.regulations.gov/fdmspublic/component/main?main=AdvancedDocket

The Docket ID is "EPA-HQ-OPP-2007-0475". 

B.8.7 Predicted environmental concentration in surface water and sediment for the active 

substance and metabolites (PECSW, PECSED) (OECD Annex AIII, 9.7, 9.8) 

The risk assessment for the EU can be found in the APPENDIX.

The risk assessment for the PMRA and the US-EPA is not included in this monograph. 

The Proposed Registration Decision – Spirotetramat (PRD2008-07), containing the detailed Canadian 

review and risk assessment, has been published by the PMRA and can be found at the PMRA’s web site 

www.pmra-arla.gc.ca. 

The registration decision made by the U.S. EPA's Office of Pesticide Program is supported by the risk 

assessments found at our Federal Docket website located at: 

http://www.regulations.gov/fdmspublic/component/main?main=AdvancedDocket

The Docket ID is "EPA-HQ-OPP-2007-0475". 
– 191 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

B.8.8 Fate and behaviour in the air 

B.8.8.1 Rate and route of degradation in air (OECD Annex IIA, 7.10, IIIA, 9.9) 

Chemical lifetime in the troposphere were calculated for the compounds 

• spirotetramat 

• spirotetramat-enol 

Reference: Calculation of the chemical lifetime of BYI08330 in the troposphere 

Author(s), year: Hellpointner, E., 2004a 

Study/Report number: M-092840-01-1, MEF-04/400 

Guideline(s): None 

GLP: Calculations - not applicable 

Validity: Study considered acceptable 

Material and methods:

Based on the calculation according to Atkinson the chemical lifetime of the parent compound spirotetramat 

(smiles notation: N1C(=O)C(c2c(C)ccc(C)c2)=C(OC(=O)OCC)C31CCC(OC)CC3) in the air was assessed by 

use of the software Atmospheric Oxidation Program (AOPWIN, 1.91). 

Findings:

Type of reaction Parameter Value 

Hydrogen abstraction [10-12 cm3 (molecule sec)-1] 26.3 

Reaction with N, S and -OH [10-12 cm3 (molecule sec)-1] 5.50 

Addition to triple bonds [10-12 cm3 (molecule sec)-1] 0.00 

Addition to olefinic bonds [10-12 cm3 (molecule sec)-1] 38.5 

Addition to aromatic rings [10-12 cm3 (molecule sec)-1] 5.87 

Addition to fused rings [10-12 cm3 (molecule sec)-1] 0.00 

Overall OH rate constant [10-12 cm3 (molecule sec)-1] 76.2 

Reactions with OH- radicals 

Half-life (12-hrs day, 1.5 × 106 OH- cm-3) [hrs] 1.69 

Overall ozone rate constant [10-17 cm3 (molecule sec)-1] 2.1 Reactions with ozone 

Half-life (12-hrs day, 7 × 1011 mol cm-3) [hrs] 13.1 

Conclusion:

The photochemical (reaction with OH radicals) half-life of the parent compound spirotetramat in the 

troposphere was estimated by the method of Atkinson to be 1.69 hours (12-hrs day; 1.5 × 10-6 OH-

 cm-3). 

Reviewer comments:

None 
– 192 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Reference: Calculation of the chemical lifetime of BYI08330-enol in the troposphere 

Author(s), year: Hellpointner, E., 2004b 

Study/Report number: M-092841-01-1, MEF-04/401 

Guideline(s): None 

GLP: Calculations - not applicable 

Validity: Study considered acceptable 

Material and methods:

Based on the calculation according to Atkinson the chemical lifetime of the metabolite spirotetramat-enol 

(smiles notation: N1C(=O)C(c2c(C)ccc(C)c2)=C(O)C31CCC(OC)CC3) in the air was assessed by use of the 

software Atmospheric Oxidation Program (AOPWIN, 1.91). 

Findings:

Type of reaction Parameter Value 

Hydrogen abstraction [10-12 cm3 (molecule sec)-1] 24.7 

Reaction with N, S and -OH [10-12 cm3 (molecule sec)-1] 5.64 

Addition to triple bonds [10-12 cm3 (molecule sec)-1] 0.00 

Addition to olefinic bonds [10-12 cm3 (molecule sec)-1] 38.5 

Addition to aromatic rings [10-12 cm3 (molecule sec)-1] 5.87 

Addition to fused rings [10-12 cm3 (molecule sec)-1] 0.00 

Overall OH rate constant [10-12 cm3 (molecule sec)-1] 74.7 

Reactions with OH- radicals 

Half-life (12-hrs day, 1.5 × 106 OH- cm-3) [hrs] 1.72 

Overall ozone rate constant [10-17 cm3 (molecule sec)-1] 2.1 Reactions with ozone 

Half-life (12-hrs day, 7 × 1011 mol cm-3) [hrs] 13.1 

Conclusion:

The photochemical (reaction with OH radicals) half-life of the metabolite spirotetramat-enol in the 

troposphere was estimated by the method of Atkinson to be 1.72 hours (12-hrs day; 1.5 × 10-6 OH- cm-3). 

Reviewer comments:

None 
– 193 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

B.8.9 Predicted environmental concentration in the air (PECA) 

The risk assessment for the EU can be found in the APPENDIX.

The risk assessment for the PMRA and the US-EPA is not included in this monograph. 

The Proposed Registration Decision – Spirotetramat (PRD2008-07), containing the detailed Canadian 

review and risk assessment, has been published by the PMRA and can be found at the PMRA’s web site 

www.pmra-arla.gc.ca. 

The registration decision made by the U.S. EPA's Office of Pesticide Program is supported by the risk 

assessments found at our Federal Docket website located at: 

http://www.regulations.gov/fdmspublic/component/main?main=AdvancedDocket

The Docket ID is "EPA-HQ-OPP-2007-0475". 
– 194 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

B.8.10 Definition of the residues (OECD Annex IIA, 7.11) 

Soil: Spirotetramat, spirotetramat-enol, spirotetramat-ketohydroxy, 4-methoxy-cyclohexanone (the 

latter a soil photolysis product) 

Surface water: Spirotetramat, spirotetramat-enol, spirotetramat-ketohydroxy, 4-methoxy-cyclohexanone, 

4-methoxy-cyclohexylaminocarboxylic acid (the two latter photolysis products) 

Sediment: Spirotetramat, spirotetramat-enol, spirotetramat-ketohydroxy 

Groundwater: Spirotetramat, spirotetramat-enol, spirotetramat-ketohydroxy, spirotetramat-MA-amide, 

4-methoxy-cyclohexanone (the latter a soil photolysis product) 

Air: Spirotetramat, spirotetramat-enol 

B.8.11 Monitoring data (OECD Annex IIA, 7.12) 

Plant protection products containing spirotetramat are not yet authorized for use. Accordingly, monitoring 

data concerning fate, behaviour and concentration in the environment are not available so far. 

B.8.12 Other/special studies (OECD Annex IIA, 7.13, AIII 9.10) 

Reference: Position Paper – Spirotetramat (BYI08330) – Fate and Behaviour (BCS 

Response to AGES Letter of Data Request 01 and 02 (2007-03-06 and 2007-

04-04) including requests from related meeting on May 04, 2007 and AGES 

Letters of Data Request 03, 04 and 05 (dated 2007-05-23, 2007-06-08 and 

2007-06-19) 

Author(s), year: Hellpointner, E., 2007 

Study/Report number: -, MEF-07/299 

Guideline(s): Position paper - not applicable 

GLP: Position paper - not applicable 

Validity: Position paper considered acceptable 

During evaluation of the submitted studies some unclear aspects mainly concerning the dimerization of 

spirotetramat-enol and other issues were identified resulting in several data requests. In the present position 

paper the notifier tried to clarify the mentioned aspects. 

Dimerization of spirotetramat-enol 

As an overview, the three existing spirotetramat aerobic soil metabolism studies with regard to the difference 

in the used application method and the analytical condition are compared (Table B.8.11-1). 
– 195 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.12-1: Compilation of aerobic soil metabolism studies. 

Study Application method Processing Observation Consequences 

Spirotetramat study 

(Babczinski, 2005)

‘Hot spot’a application 

(due to insolubility in 

water) 

Acidic processing 

Spirotetramatenol is to some 

degree unstable 

in acidic 

environment 

Application method 

only usable for parent 

kinetics and 

metabolite 

identification 

separate soil 

metabolism study 

was conducted with 

spirotetramat-enol 

Spirotetramat-enol study

(Babczinski, 2006b)

Broadcastb

application 

(realistic conditions) 

Alkaline processing 

(sufficiently soluble 

in water) 

Valid 

spirotetramatenol degradation 

possible 

- 

Outdoor study 

(Babczinski, 2006a) 

Broadcastb

application with 

formulation 

(realistic conditions) 

Acidic processing - - 

a

 Dosing the soil with a low volume of higher concentrated organic test solution (acetonitrile) 

b

 Dosing the soil with a higher volume of low concentrated aqueous test solution 

In the Table B.8.11-2 an overview over the different soil metabolism and dissipation studies with regard to 

dimer formation is provided. 

Table B.8.12-2: Compilation on the formation of spirotetramat-enol dimers. 

Test item Study type Scenario Application 

mode Tier Processing 

Max. observed dimer 

value (% of applied) 

Spirotetramat Aerobic soil 

metabolism Lab ‘Hot spot’ (acetonitrile) Worst case Acidic 12.7 

Spirotetramat-enol Aerobic soil 

metabolism Lab Broadcast (water) 

Approaching 

real case Alkaline 5.0 

Spirotetramat Aerobic soil 

metabolism 

Outdoor 

(semifield) 

Broadcast 

(formulation 

OD 100) 

Similar to 

real case Acidic 1.5 

Spirotetramat 

Terrestrial 

field 

dissipation 

Field 

Broadcast 

(formulation 

OD 100) 

Real world Acidic 0.2 

By comparing the two standard laboratory studies it was shown that the dimer formation was higher in the 

parent study with ‘hot spot’ application than in the spirotetramat-enol study with broadcast application (more 

realistic environmental conditions). 

Furthermore, within the parent study itself, much lower portions of dimers (< 5 % of AR) were found in the 

US soil ‘Molino’ which received a much lower concentrated treatment solution than the 3 EU soils (dimer 

formation up to 12.7 % of AR). The results of the spirotetramat-enol study clearly show that spirotetramatenol dimer 1 and 2 are minor transformation products in soils. This holds also for the outdoor study with the 

formulated product. 

Further, the reviewer noted that in the raw data from the US terrestrial field dissipation studies some semiquantitative dimer data were extracted. Since these data could not be fully validated due to the lack of 

appropriate dimer reference standards it was not reported in the original TFD report. However, they give a 

clear indication of the significance of these dimers under field conditions since soil extracts were analyzed by 

LC-MS also for m/z 600 signals at the retention times of both dimers (ROI 6 and ROI 7). The maximum dimer 

formation in field was below a concentration of 0.2 % of applied. 
– 196 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Concluding, the dimers were thoroughly investigated but are not taken into account for further risk 

assessment owing to their artificial formation observed in lab studies as well as due to their very low levels 

under outdoor/field conditions. It is evident that under real case scenarios (broadcast application) even in the 

lab studies dimers do not play a significant role and are therefore considered not relevant. 

Chemical pathway of spirotetramat-enol dimer formation/degradation 

Based on the spirotetramat-enol dimers molecular weight of m/z 600 (601 = M+H in ESI positive LC.MS) and 

their fragment m/z 301 (302 = M+H in ESI positive LC-MS/MS) in the LC-MS experiment, a dimeric structure 

composed of two spirotetramat-enols was derived. The dimers molecular weight of 600 is two mass units 

(hydrogen) lower than the sum of two times m/z 301 (the molecular weight of the enol). Therefore, an 

oxidative dimerization of spirotetramat-enol or a dimerization of spirotetramat-enol with spirotetramatketohydroxy under the formation of an ether linkage (spirotetramat-enol dimer 1) is proposed as the 

respective chemical reaction. As reaction partners, one spirotetramat-enol molecule in the ketoform of the 

ketoenol tautomers and one spirotetramat-enol in the enolform of the ketoenol tautomers are proposed 

(Figure B.8.11-1). Alternatively, a dimerization of one spirotetramat-enol molecule with a spirotetramatketohydroxy molecule (formed by previous enol oxidation) might be assumed. Further it was agreed that it is 

likely that a dimer like the one shown in the figure below may hydrolyze to spirotetramat-enol and 

spirotetramat-ketohydroxy. 

Figure B.8.12-1: Proposed chemical pathway of spirotetramat-enol dimer formation/degradation 

‘Immobile’ fraction of spirotetramat-enol - comparability of behaviour under lab and field conditions 

The kinetic evaluation of the metabolites was based on the laboratory study, in which the test item was 

applied at realistic local concentrations. Therefore only low amounts of the dimers were observed 

(comparable to those under outdoor/field conditions) and in this study the dimers did not play a significant 

role. Therefore, the dimers were not considered in the kinetic evaluation. In the kinetic evaluation the 

immobile fraction of spirotetramat-enol is defined as part of the observed spirotetramat-enol. The actual 

value of the immobile fraction was established by fitting the SFO-RB (single first order reversible binding) 

model to observed spirotetramat-enol concentrations (for detail see kinetic evaluation of the metabolites, 

Röpke, 2006a). In the SFO-RB model the immobile (also called protected) fraction represents a fraction of 
– 197 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

spirotetramat-enol, which is less available and thus leads to the observed bi-phasic degradation behaviour. 

However, this portion was not based on any observed dimer concentration, but is part of the observed 

spirotetramat-enol concentrations. 

To point out that a comparability of the degradation behaviour of spirotetramat and its metabolites under 

laboratory conditions and under real outdoor conditions is given, the US field dissipation trial were fully 

modelled with the data set suggested for environmental risk assessment (see study by Röpke and 

Ramanarayanan, 2007). The prediction of the soil residues was based on the kinetic parameters derived 

from laboratory metabolism studies and considered the specific environmental conditions of the field trials. In 

general, the results showed that the comparison verified the kinetic parameters for spirotetramat-enol and 

spirotetramat-ketohydroxy derived from the laboratory study. 

Overall conclusion on the dimerization issue 

Concluding, the dimers do not contribute major metabolites. The occurrence of dimers does not significantly 

influence the environmental behaviour of spirotetramat and its major metabolites under field conditions. The 

derived environmental parameters are representative for the behaviour of spirotetramat and its major 

metabolites under field conditions. 

Comment (reviewer):

• The statements concerning the dimerization of spirotetramat-enol are considered acceptable. 

• With regard to the reviewer’s data requests number 02, 03, 04 and 05 most of the statements of the 

notifier were included directly in the respective studies. 
– 198 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Physical-chemical data on spirotetramat metabolites spirotetramat-enol and spirotetramat-ketohydroxy were 

investigated in the following studies: 

Reference: Water Solubility of BYI08330-enol (AE 1302944) at pH 5, pH 7 and pH 8 (Flask 

Method) 

Author(s), year: Eyrich, U., Bogdoll, B., 2006 

Study/Report number: M-275829-01-2, PA-06/035 

Guideline(s): Guideline 92/69/EEC, appendix A.6; OECD-Guideline 105 

GLP: Yes 

Validity: Study considered acceptable 

Summary:

The water solubility of spirotetramat-enol at pH 5, pH 7 and pH 8 has been determined according to the ‘flask 

method’ described in guideline 92/69/EEC, appendix A.6 and OECD-guideline 105. 

Table B.8.12-3: Water solubility of spirotetramat-enol. 

System pH rangea Solubility at 20°C [g L-1] SD [g L-1] RSD [%] 

buffer pH 5 4.98 0.09 0.01 14.3 

buffer pH 7 6.97 – 6.99 2.7 0.003 0.1 

buffer pH 8b 7.82 – 7.83 28 0.3 1.0 

a

 pH-range of 3 experiments 

b

 Due to the strong acidic character of the test item the buffer capacity of the used buffer pH 9 was not sufficient. Therefore, the pH 

value of the saturated solution declined to pH 8. 

Reviewer comments:

None 

Reference: Partition Coefficients 1-Octanol/Water of BYI08330-enol (AE 1302944) at pH 

5, pH 7 and pH 9 (Shake flask method) 

Author(s), year: Bogdoll, B., Eyrich, U., 2006 

Study/Report number: M-276091-01-2, PA-06/036 

Guideline(s): EEC Test Guideline 92/69, A.8.; OECD Test Guideline 107 

GLP: Yes 

Validity: Study considered acceptable 

Summary:

The partition coefficients 1-octanol/water of the test item spirotetramat-enol at pH 5, pH 7 and pH 9 at room 

temperature have been determined according to the ‘flask-shaking’ method described in EEC Test Guideline 

92/69, A.8. and OECD Test Guideline 107. 

Table B.8.12-4: Partition coefficients (1-octanol/water) of spirotetramat-enol. 

Parameter pH 5 pH 7 pH 9 

Log(POW) 2.0 0.3 -1.3 

POW 109 2.1 0.05 

Reviewer comments:

None 
– 199 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Reference: BYI08330-enol (AE 1302944): Determination of the Dissociation Constant 

(Spectrophotometric Screening Method) 

Author(s), year: Bogdoll, B., Lemke, G., Kaußmann., M. 2006 

Study/Report number: M-274084-01-2, AF06/031 

Guideline(s): Based on OECD Test Guideline 112 

GLP: None GLP screening test 

Validity: Study considered acceptable 

Summary:

The dissociation constant of spirotetramat-enol was determined using a spectrophotometric method, based 

on the OECD-Guideline 112. The experimental work has been performed by Dr. M. Kaußmann (PT - 

Analytics Monheim). An instrument for pKa screening measurements from Sirius Analytical Instruments Ltd 

(UK) was used (type GLpKa with D-Pas, Dip Probe Absorption Spectroscopy). 

The dissociation constant (pKa) of spirotetramat-enol was 5.2. 

Reviewer comments:

None 

Reference: Water Solubility of BYI 08330-cis-ketohydroxy in Distilled Water 

(Flask Method) 

Author(s), year: Bogdoll, B., Lemke, G., 2005a 

Study/Report number: M-268425-01-2, PA05/099 

Guideline(s): Guideline 92/69/EEC, appendix A.6; OECD-Guideline 105 

GLP: Yes 

Validity: Study considered acceptable 

Summary:

The water solubility of spirotetramat-ketohydroxy has been determined in distilled water according to the 

‘flask method’ described in guideline 92/69/EEC, appendix A.6 and OECD-guideline 105. 

Table B.8.12-5: Water solubility of spirotetramat-ketohydroxy in distilled water. 

Solubility at 20°C [g L-1] SD [g L-1] RSD [%] 

0.228 0.0042 1.8 

Reviewer comments:

None 

Reference: Partition Coefficient 1-Octanol/Water of BYI08330-cis-ketohydroxy 

(HPLC Method) 

Author(s), year: Bogdoll, B., Lemke, G., 2005b 

Study/Report number: M-268428-01-2, PA05/098 

Guideline(s): 92/69/EEC A.8, OECD TG 117, OPPTS 830.7570 

GLP: Yes 

Validity: Study considered acceptable 

Summary:
– 200 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

The partition coefficient (1-octanol/water) of spirotetramat-ketohydroxy was determined according to OECD 

test guideline 117, EEC-guideline 92/69/EEC A.8 and EPA guideline OPPTS 830.7570, HPLC-method. Nine 

calibration substances were injected into a HPLC-system under the same analytical conditions (column 

temperature 40 °C) as the test item. Calibration curves were created by using the measured retention times 

(log(k’) values) and the known log(POW) values of the calibration substances for linear regression. 

The measured log(k’) values of the test item were within the calibrated log(k’) range. From the resulted 

calibration curves and their equations the log(POW) of the substance has been interpolated. 

Table B.8.12-6: Partition coefficients (1-octanol/water) of spirotetramat-ketohydroxy. 

Parameter pH 7 

Log(POW) 1.3 

POW 20 

Reviewer comments:

None 

Reference: BYI08330-cis-ketohydroxy (AE 1422479): Determination of the Dissociation 

Constant (Spectrophotometric Screening Method) 

Author(s), year: Bogdoll, B., Lemke, G., Kaußmann., M., 2005 

Study/Report number: M-263603-01-2, AF05/098 

Guideline(s): Based on OECD Test Guideline 112 

GLP: None GLP screening test 

Validity: Study considered acceptable 

Summary:

The dissociation constant of spirotetramat-ketohydroxy was determined by using a spectrophotometric 

method based on the OECD Test Guideline 112. The experimental work has been performed by Dr. M. 

Kaußmann (PT - Analytics Monheim). An instrument for pKa screening measurements from Sirius Analytical 

Instruments Ltd (UK) was used (type GLpKa with D-Pas, Dip Probe Absorption Spectroscopy). 

The dissociation constant (pKa) of spirotetramat-ketohydroxy was 11.0. 

Reviewer comments:

None 
– 201 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

B.8.13 References relied on 

Annex point/ 

reference 

number 

Author(s) Year 

Title 

Source (where different from company) 

Company, Report No 

GLP or GEP status (where relevant) 

Published or not 

Data 

Protection 

Claimed 

Y/N-R/NR 

Owner 

OECD Annex II Data and Information 

KIIA, 7.1.1 

KIIA, 7.2.1 

Babczinski, P. 2005 Aerobic degradation/metabolism of BYI8330 in 

four different soils 

Bayer CropScience AG, 

Report No.: MEF-04/169, 

Edition Number: M-256849-02-2 

Date: 07.07.2005, Amended: 05.05.2006 

GLP, unpublished 

Yes BCS 

KIIA, 7.1.1 Babczinski, P. 2006a Outdoor metabolism of [azaspirodecenyl-3-

14C]BYI08330 in two soils 

Bayer CropScience AG, 

Report No.: MEF-06/041, 

Edition Number: M-270597-01-2 

Date: 03.04.2006 

GLP, unpublished 

Yes BCS 

KIIA, 7.1.1, 

KIIA, 7.2.3 

Babczinski, P. 2006b [Azaspirodecenyl-3-14C]- and 

[azaspirodecenyl-5-14C]-labelled BYI08330-cisenol: Comparative aerobic soil 

metabolism/degradation in four soils 

Bayer CropScience AG, 

Report No.: MEF-05/157, 

Edition Number: M-269304-01-2 

Date: 17.01.2006 

GLP, unpublished 

Yes BCS 

KIIA, 7.1.2, 

KIIA, 7.2.4 

Menke, U. 2006a BYI08330: Anaerobic soil metabolism 

Bayer CropScience AG, 

Report No.: MEF-05/515, 

Edition Number: M-270739-01-2 

Date: 03.05.2006 

GLP, unpublished 

Yes BCS 

KIIA, 7.1.3 Heinemann, 

O. 

2005a [Azaspirodecenyl-3-14C]- and 

[azaspirodecenyl-5-14C]BYI08330: 

Phototransformation on soil 

Bayer CropScience AG, 

Report No.: MEF-04/481, 

Edition Number: M-252907-01-2 

Date: 25.04.2005 

GLP, unpublished 

Yes BCS 

KIIA, 7.2.1, 

KIIA, 7.1.1 

Babczinski, P. 2005 Aerobic degradation/metabolism of BYI8330 in 

four different soils 

Bayer CropScience AG, 

Report No.: MEF-04/169, 

Edition Number: M-256849-02-2 

Date: 07.07.2005, Amended: 05.05.2006 

GLP, unpublished 

Yes BCS 

KIIA, 7.2.1 Ramanarayan

an, T.; 

Roepke, B. 

2006 Degradation of BYI08330 in four soils under 

aerobic conditions: kinetic evaluation 

Bayer CropScience AG, 

Report No.: MEF-05/249, 

Edition Number: M-277096-01-2 

Date: 30.08.2006 

Non GLP, unpublished 

Yes BCS 
– 202 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Annex point/ 

reference 

number 

Author(s) Year 

Title 

Source (where different from company) 

Company, Report No 

GLP or GEP status (where relevant) 

Published or not 

Data 

Protection 

Claimed 

Y/N-R/NR 

Owner 

KIIA, 7.2.3 

KIIA, 7.1.1 

Babczinski, P. 2006b [Azaspirodecenyl-3-14C]- and 

[azaspirodecenyl-5-14C]-labelled BYI08330-cisenol: Comparative aerobic soil 

metabolism/degradation in four soils 

Bayer CropScience AG, 

Report No.: MEF-05/157, 

Edition Number: M-269304-01-2 

Date: 17.01.2006 

GLP, unpublished 

Yes BCS 

KIIA, 7.2.3 Roepke, B. 2006a Kinetic evaluation of laboratory soil 

degradation studies of BYI08330-Enol, 

BYI08330-ketohydroxy, BYI08330-MA-amide 

Bayer CropScience AG, 

Report No.: MEF-06/199, 

Edition Number: M-277178-03-1 

Date: 30.08.2006, Amended: 23.08.2007 

Non GLP, unpublished 

Yes BCS 

KIIA, 7.2.3 Dehner, D.; 

Heinemann, 

O. 

2006 [Carbonyl-14C] 4-methoxycyclohexanone: 

Aerobic soil degradation in three soils 

Bayer CropScience AG, 

Report No.: MEF-05/485, 

Edition Number: M-269022-02-2 

Date: 28.02.2006, Amended: 18.07.2006 

GLP, unpublished 

Yes BCS 

KIIA, 7.2.4, 

KIIA, 7.1.2 

Menke, U. 2006a BYI08330: Anaerobic soil metabolism 

Bayer CropScience AG, 

Report No.: MEF-05/515, 

Edition Number: M-270739-01-2 

Date: 03.05.2006 

GLP, unpublished 

Yes BCS 

KIIA, 7.3.1 Netzband, D. 

J. 

2006a In house laboratory validation of an analytical 

method for the determination of BYI08330 and 

its metabolites BYI08330-enol, BYI08330-

ketohydroxy and BYI08330-MA-amide in soil 

and sediment by LC/MS/MS 

Bayer CropScience, Stilwell, KS, USA 

Bayer CropScience AG, 

Report No.: RAFNX012, 

Edition Number: M-277365-01-1 

Method Report No US: RAFNX012 

Date: 29.08.2006 

GLP, unpublished 

Yes BCS 

KIIA, 7.3.1 Lenz, Mark 2006a Terrestrial field dissipation of BYI08330 in New 

York soil, 2004 

Bayer CropScience, Stilwell, KS, USA 

Bayer CropScience AG, 

Report No.: MEFNY004, 

Edition Number: M-277191-01-1 

Date: 05.09.2006 

GLP, unpublished 

Yes BCS 
– 203 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Annex point/ 

reference 

number 

Author(s) Year 

Title 

Source (where different from company) 

Company, Report No 

GLP or GEP status (where relevant) 

Published or not 

Data 

Protection 

Claimed 

Y/N-R/NR 

Owner 

KIIA, 7.3.1 Lenz, Mark 2006b Terrestrial field dissipation of BYI08330 in 

Florida soil, 2004 

Bayer CropScience, Stilwell, KS, USA 

Bayer CropScience AG, 

Report No.: MEFNX055, 

Edition Number: M-277184-01-1 

Date: 05.09.2006 

GLP, unpublished 

Yes BCS 

KIIA, 7.3.1 Lenz, Mark 2006c Terrestrial field dissipation of BYI08330 in 

California soil, 2004 

Bayer CropScience, Stilwell, KS, USA 

Bayer CropScience AG, 

Report No.: MEFNY002, 

Edition Number: M-277186-01-1 

Date: 05.09.2006 

GLP, unpublished 

Yes BCS 

KIIA, 7.3.1 Lenz, Mark 2006d Terrestrial field dissipation of BYI08330 in 

Washington soil, 2004 

Bayer CropScience, Stilwell, KS, USA 

Bayer CropScience AG, 

Report No.: MEFNY003, 

Edition Number: M-277189-01-1 

Date: 05.09.2006 

GLP, unpublished 

Yes BCS 

KIIA, 7.3.1 Netzband, D. 

J. 

2006b Stability of AE 0317309 and AE B197555 in 

soil during frozen storage, USA, 2005 

(reported through a maximum of 320 days 

storage) 

Bayer CropScience, Stilwell, KS, USA 

Bayer CropScience AG, 

Report No.: RAFNX018, 

Edition Number: M-277371-01-1 

Date: 29.08.2006 

GLP, unpublished 

Yes BCS 

KIIA, 7.3.1 Brumhard, B. 2006 Independent laboratory validation of method 

FN-002-S05-02 for the determination of 

BYI08330 and its metabolites BYI08330-enol, 

BYI08330-keto-hydroxy and BYI08330-MAamide in soil and sediment by LS/MS/MS 

Bayer CropScience, Stilwell, KS, USA 

Bayer CropScience AG, 

Report No.: MR-06/037, 

Edition Number: M-276038-01-2 

Date: 14.08.2006 

GLP, unpublished 

Yes BCS 

KIIA, 7.4.1 Haas, M. 2005 BYI08330: Adsorption/desorption in five soils 

Bayer CropScience AG, 

Report No.: MEF-04/373, 

Edition Number: M-266755-01-2 

Date: 21.10.2005 

GLP, unpublished 

Yes BCS 
– 204 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Annex point/ 

reference 

number 

Author(s) Year 

Title 

Source (where different from company) 

Company, Report No 

GLP or GEP status (where relevant) 

Published or not 

Data 

Protection 

Claimed 

Y/N-R/NR 

Owner 

KIIA, 7.4.2 Hein, W. 2005a Adsorption/desorption of BYI08330-cis-enol in 

five different soils 

Rheinland-Pfalz AgroScience GmbH, 

Neustadt, Germany 

Bayer CropScience AG, 

Report No.: IM2000, 

Edition Number: M-267858-01-2 

Date: 05.09.2005 

GLP, unpublished 

Yes BCS 

KIIA, 7.4.2 Hein, W. 2005b 14C-BYI08330-ketohydroxy: 

Adsorption/desorption in five soils 

Rheinland-Pfalz AgroScience GmbH, 

Neustadt, Germany 

Bayer CropScience AG, 

Report No.: IM2001, 

Edition Number: M-267955-02-2 

Date: 09.09.2005, Amended: 30.08.2006 

GLP, unpublished 

Yes BCS 

KIIA, 7.4.2 Simmonds, 

M.; Early, E. 

2005 [14C]-BYI08330-MA-amide: Adsorption to and 

desorption from five soils 

Battelle UK Ltd.; Ongar; United Kingdom 

Bayer CropScience AG, 

Report No.: CX/04/070, 

Edition Number: M-263686-01-2 

Date: 07.09.2005 

GLP, unpublished 

Yes BCS 

KIIA, 7.4.4 Babczinski, P. 2006c BYI08330-enol: Soil column leaching 

Bayer CropScience AG, 

Report No.: MEF-05/356, 

Edition Number: M-270280-02-2 

Date: 24.03.2006, Amended: 22.05.2006 

GLP, unpublished 

Yes BCS 

KIIA, 7.5, 

KIIA, 2.9.1 

Heinemann, 

O. 

2004a [Azaspirodecenyl-3-14C]- and 

[azaspirodecenyl-5-14C]BYI08330: Hydrolytic 

degradation 

Bayer CropScience AG, 

Report No.: MEF-04/176, 

Edition Number: M-093124-01-2 

Date: 08.09.2004 

GLP, unpublished 

Yes BCS 

KIIA, 7.5 Heinemann, 

O. 

2004b [Azaspirodecenyl-3-14C]- and 

[azaspirodecenyl-5-14C]BYI08330-enol: 

Hydrolytic degradation 

Bayer CropScience AG, 

Report No.: MEF-04/311, 

Edition Number: M-242999-01-2 

Date: 03.12.2004 

GLP, unpublished 

Yes BCS 

KIIA, 7.6 Stupp, H. - P. 2005a BYI08330: Phototransformation of BYI08330 in 

sterile water 

Bayer CropScience AG, 

Report No.: MEF-05/206, 

Edition Number: M-266695-01-2 

Date: 15.11.2005 

GLP, unpublished 

Yes BCS 
– 205 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Annex point/ 

reference 

number 

Author(s) Year 

Title 

Source (where different from company) 

Company, Report No 

GLP or GEP status (where relevant) 

Published or not 

Data 

Protection 

Claimed 

Y/N-R/NR 

Owner 

KIIA, 7.6, 

KIIA, 2.9.4 

Stupp, H. - P. 2005b [Azaspirodecenyl-3-14C]BYI08330 and 

[Azaspirodecenyl-5-14C]BYI08330: 

Phototransformation in natural water 

Bayer CropScience AG, 

Report No.: MEF-05/262, 

Edition Number: M-266753-01-2 

Date: 15.11.2005 

GLP, unpublished 

Yes BCS 

KIIA, 7.6, 

KIIA, 2.9.3, 

KIIA, 2.9.4 

Heinemann, 

O. 

2004c BYI08330: Determination of the quantum yield 

and assessment of the environmental half-life 

of the direct photodegradation in water 

Bayer CropScience AG, 

Report No.: MEF-04/080, 

Edition Number: M-092941-01-2 

Date: 28.09.2004 

GLP, unpublished 

Yes BCS 

KIIA, 7.6 Heinemann, 

O. 

2005b BYI08330-enol: Determination of the quantum 

yield and assessment of the environmental 

half-life of the direct photodegradation in water 

Bayer CropScience AG, 

Report No.: MEF-04/438, 

Edition Number: M-243787-01-2 

Date: 10.01.2005 

GLP, unpublished 

Yes BCS 

KIIA, 7.7 Weyers, A. 2005 BYI 08330 - Biodegradation 

Bayer Industry Services, Leverkusen, 

Germany 

Bayer CropScience AG, 

Report No.: 2005/0077/01, 

Edition Number: M-263287-01-1 

Date: 16.11.2005 

GLP, unpublished 

Yes BIS 

KIIA, 7.8.3 Menke, U. 2006c BYI08330: Aerobic aquatic metabolism 

Bayer CropScience AG, 

Report No.: MEF-04/511, 

Edition Number: M-269307-01-2 

Date: 29.03.2006 

GLP, unpublished 

Yes BCS 

KIIA, 7.8.3 Roepke, B. 2006b Kinetic evaluation of the aerobic aquatic 

metabolism of BYI08330, BYI08330-enol and 

BYI08330-ketohydroxy in water sediment 

systems 

Bayer CropScience AG, 

Report No.: MEF-06/279, 

Edition Number: M-277415-01-1 

Date: 30.08.2006 

Non GLP, unpublished 

Yes BCS 

KIIA, 7.8.3 Shepherd, J.; 

Arthur, E. L.; 

Dominic, A. 

2005 BYI08330[azaspirodecenyl-3-14C]: Anaerobic 

aquatic metabolism 

Bayer CropScience, Stilwell, KS, USA 

Bayer CropScience AG, 

Report No.: MEFNX015, 

Edition Number: M-261943-01-1 

Date: 06.12.2005 

GLP, unpublished 

Yes BCS 
– 206 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Annex point/ 

reference 

number 

Author(s) Year 

Title 

Source (where different from company) 

Company, Report No 

GLP or GEP status (where relevant) 

Published or not 

Data 

Protection 

Claimed 

Y/N-R/NR 

Owner 

KIIA, 7.10, 

KIIA, 2.10 

Hellpointner, 

E. 

2004a Calculation of the chemical lifetime of BYI 

08330 in the troposphere 

Bayer CropScience AG, 

Report No.: MEF-04/400, 

Edition Number: M-092840-01-1 

Date: 14.09.2004 

Non GLP, unpublished 

Yes BCS 

KIIA, 7.10 Hellpointner, 

E. 

2004b Calculation of the chemical lifetime of BYI 

08330-enol in the troposphere 

Bayer CropScience AG, 

Report No.: MEF-04/401, 

Edition Number: M-092841-01-1 

Date: 21.09.2004 

Non GLP, unpublished 

Yes BCS 

KIIA, 7.13 Hellpointner, 

E. 

2007 Position Paper: Spirotetramat (BYI08330) – 

Fate and Behaviour 

Bayer CropScience Deutschland GmbH, 

Frankfurt am Main, Germany 

Bayer CropScience AG, 

Report No.: MEF-07/299, 

Edition Number: - 

Date: 06.07.2007 

GLP, unpublished 

Yes BCS 

KIIA, 7.13 Eyrich, U.; 

Bogdoll, B. 

2006 Water solubility of BYI 08330-enol (AE 

1302944) at pH 5, pH 7 and pH 8 (Flask 

Method) 

Bayer CropScience GmbH, Frankfurt am Main, 

Germany 

Bayer CropScience AG, 

Report No.: PA06/035, 

Edition Number: M-275829-01-2 

Date: 11.08.2006 

GLP, unpublished 

Yes BCS 

KIIA, 7.13 Bogdoll, B.; 

Eyrich, U. 

2006 Partition coefficients 1-Octanol / water of BYI 

08330-enol (AE 1302944) at pH 5, pH 7 and 

pH 9 (Shake flask method) 

Bayer CropScience Deutschland GmbH, 

Frankfurt am Main, Germany 

Bayer CropScience AG, 

Report No.: PA06/036, 

Edition Number: M-276091-01-2 

Date: 17.08.2006 

GLP, unpublished 

Yes BCS 

KIIA, 7.13 Bogdoll, B.; 

Lemke, G.; 

Kaussmann, 

M. 

2006 BYI 08330-enol (AE 1302944) - Determination 

of the dissociation constant 

(spectrophotometric screening method) 

Bayer CropScience GmbH, Frankfurt am Main, 

Germany 

Bayer CropScience AG, 

Report No.: AF06/031, 

Edition Number: M-274084-01-2 

Date: 05.07.2006 

Non GLP, unpublished 

Yes BCS 
– 207 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Annex point/ 

reference 

number 

Author(s) Year 

Title 

Source (where different from company) 

Company, Report No 

GLP or GEP status (where relevant) 

Published or not 

Data 

Protection 

Claimed 

Y/N-R/NR 

Owner 

KIIA, 7.13 Bogdoll, B.; 

Lemke, G. 

2005a Water solubility of BYI 08330-cis-ketohydroxy 

in distilled water (flask method) 

Siemens AG, Frankfurt am Main, Germany 

Bayer CropScience AG, 

Report No.: PA05/099, 

Edition Number: M-268425-01-2 

Date: 06.09.2005 

GLP, unpublished 

Yes BCS 

KIIA, 7.13 Bogdoll, B.; 

Lemke, G. 

2005b BYI 08330-cis-ketohydroxy partition coefficient 

1-Octanol/water (HPLC-method) 

Bayer CropScience GmbH, Frankfurt am Main, 

Germany 

Bayer CropScience AG, 

Report No.: PA05/098, 

Edition Number: M-268428-01-2 

Date: 06.09.2005 

GLP, unpublished 

Yes BCS 

KIIA, 7.13 Bogdoll, B.; 

Lemke, G.; 

Kaussmann, 

M. 

2005 BYI 08330-cis-ketohydroxy (AE 1422479) 

Determination of the dissociation constant 

(spectrophotometric screening method) - 

Code: PBF-2005-0070-TOX-06867 

Bayer CropScience GmbH, Frankfurt am Main, 

Germany 

Bayer CropScience AG, 

Report No.: AF05/098, 

Edition Number: M-263603-01-2 

Date: 16.12.2005 

Non GLP, unpublished 

Yes BCS 

OECD Annex III Data and Information 

KIIIA, 9.4, 

KIIIA, 9.5 

Roepke, B. 2006a Predicted environmental concentrations of 

spirotetramat and its main metabolites in soil 

(PECsoil); Use in citrus in Europe. 

Bayer CropScience AG, 

Report No.: MEF-06/282, 

Edition Number: M-277210-01-1 

Date: 20.08.2006, 

Non GLP, unpublished 

Yes BCS 

KIIIA, 9.4, 

KIIIA, 9.5 

Roepke, B. 2006b Predicted environmental concentrations of 

spirotetramat and its main metabolites in soil 

(PECsoil); Use in leafy vegetables in Europe. 

Bayer CropScience AG, 

Report No.: MEF-06/387, 

Edition Number: M-277222-01-1 

Date: 20.08.2006, 

Non GLP, unpublished 

Yes BCS 

KIIIA, 9.4, 

KIIIA, 9.5 

Roepke, B. 2007a Predicted environmental concentrations of 4-

methoxy cyclohexanone in soil (PECsoil). 

Bayer CropScience AG, 

Report No.: MEF-07/478, 

Edition Number: M-295000-01-1, 

Date: 15.11.2007 

Non GLP, unpublished 

Yes BCS 
– 208 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Annex point/ 

reference 

number 

Author(s) Year 

Title 

Source (where different from company) 

Company, Report No 

GLP or GEP status (where relevant) 

Published or not 

Data 

Protection 

Claimed 

Y/N-R/NR 

Owner 

KIIIA, 9.6, 

KIIIA, 9.6.1, 

KIIIA, 9.6.2 

Roepke, B. 2006c Predicted environmental concentrations of 

spirotetramat and its main soil metabolites in 

groundwater recharge (PECgw) based on 

calculations with FOCUS PEARL; Use in citrus 

in Europe. 

Bayer CropScience AG, 

Report No.: MEF-06/280, 

Edition Number: M-277121-02-2, 

Date: 30.08.2006, Amended: 12.06.2007, 

Non GLP, unpublished 

Yes BCS 

KIIIA, 9.6, 

KIIIA, 9.6.1, 

KIIIA, 9.6.2 

Roepke, B. 2006d Predicted environmental concentrations of 

spirotetramat and its main soil metabolites in 

groundwater recharge (PECgw) based on 

calculations with FOCUS PEARL; Use in leafy 

vegetables in Europe. 

Bayer CropScience AG, 

Report No.: MEF-06/385, 

Edition Number: M277164-02-2, 

Date: 30.08.2006, Amended: 12.06.2007, 

Non GLP, unpublished 

Yes BCS 

KIIIA, 9.6, 

KIIIA, 9.6.1, 

KIIIA, 9.6.2 

Roepke, B. 2007b Predicted environmental concentrations of 4-

methoxy cyclohexanone in groundwater 

recharge (PECgw) based on calculations with 

FOCUS PEARL. 

Bayer CropScience AG, 

Report No.: MEF-07/477, 

Edition Number: M-294996-01-1, 

Date: 15.11.2007, 

Non GLP, unpublished 

Yes BCS 

KIIIA, 9.7, 

KIIIA, 9.8 

Roepke, B. 2006e Predicted environmental concentrations of 

spirotetramat and its main metabolites in 

surface water and sediment (PECsw/sed) 

calculated according to FOCUS; Use in citrus 

in Europe. 

Bayer CropScience AG, 

Report No.: MEF-06/281, 

Edition Number: M-277190-01-1 

Date: 30.08.2006, 

Non GLP, unpublished 

Yes BCS 

KIIIA, 9.7, 

KIIIA, 9.8 

Roepke, B. 2006f Predicted environmental concentrations of 

spirotetramat and its main metabolites in 

surface water and sediment (PECsw/sed) 

calculated according to FOCUS; Use in leafy 

vegetables in Europe. 

Bayer CropScience AG, 

Report No.: MEF-06/386, 

Edition Number: M-277176-01-1 

Date: 30.08.2006, 

Non GLP, unpublished 

Yes BCS 
– 209 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

APPENDIX 

Spirotetramat 

B.8 Fate and behaviour in the environment 

Risk assessment for the EU (Annex III) 
– 210 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

B.8.3 Predicted environmental concentration in soil (PECS) for the active substance and 

relevant metabolites (OECD Annex IIIA, 9.4, 9.5) 

Reference: Predicted environmental concentrations of spirotetramat and its main 

metabolites in soil (PECsoil): Use in citrus in Europe 

Author(s), year: Röpke, B., 2006a 

Study/report number: M-277210-01-1/MEF-06/282 

Guideline(s): Calculations – Not applicable 

GLP: Calculations – Not applicable 

Deviations: Calculations – Not applicable 

Validity: Study considered acceptable 

and 

Reference: Predicted environmental concentrations of spirotetramat and its main 

metabolites in soil (PECsoil): Use in leafy vegetables in Europe 

Author(s), year: Röpke, B., 2006b 

Study/report number: M-277222-01-1/MEF-06/387 

Guideline(s): Calculations – Not applicable 

GLP: Calculations – Not applicable 

Deviations: Calculations – Not applicable 

Validity: Study considered acceptable 

and 

Reference: Predicted Environmental Concentrations of 4-methoxy cyclohexanone in 

Soil (PECsoil) 

Author(s), year: Röpke, B., 2007a 

Study/report number: M-295000-01-1/MEF-07/478 

Guideline(s): Calculations – Not applicable 

GLP: Calculations – Not applicable 

Deviations: Calculations – Not applicable 

Validity: Study considered acceptable 

Material and methods:

The initial PECS [mg kg-1] of the active ingredient from a single application depends on the application rate A 

[g ha-1] of the compound, on the crop interception C [%], on the bulk density BD of the dry soil [g cm-3] 

(standard value 1.5 g cm-3) and on the assumed mixing depth d [cm] (standard value 5 cm), according to 

PECS,init = A × (1 – 0.01 × C) / (100 × BD × d) 

In single application scenarios, the initial PECS is equal to the overall maximum. Based on the maximum 

PECS and assuming simple first-order kinetics (SFO) with degradation rate k [d-1] (k = ln(2)/DT50), the soil 

concentration over time [d] are given by 

PECS(t) = PECS,max × e-k × t
– 211 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

For a comparison with effect endpoints from long-term (chronic) ecotoxicological studies, it is sometimes 

more appropriate to use time-weighted average (TWA) exposure concentrations. For SFO kinetics, the TWA

concentrations are given by 

TWAS(t) = PECS,max × 1 / (k × t) × (1 – e-k × t) 

For the calculation of the maximum PECS of a metabolite, the maximum amount of a metabolite, XMet,s,max [% 

of applied parent compound] that was observed in a degradation study, and the molar masses of parent, MP, 

and MMet [g mol-1], must be taken into account: 

PECMet,s,init = A × (1 – 0.01 × C) × 1 / (100 × BD × d) × 0.01 × XMet,s,max × (MMet / MP) 

PECS and TWAS values of a metabolite are calculated correspondingly to the parent, using the degradation 

rate of the metabolite, kMet. 

Table B.8.3-1: Application data of spirotetramat applied as OD 150 formulation. 

Crop Citrus Leafy vegetables 

Application rate [g ha-1] 288a 72 

Number of applications 2 2 

Interval [days] 21 14 

Crop interception [%] 70b 70c

BBCH code 71 – 78 42 - 43 

Soil depth [cm] 5 5 

Soil density [g cm-3] 1.5 1.5 

a Maximum application rate assuming 96 g ai ha-1 m-1 tree height (maximum tree height 3 m) 

b

 FOCUS default value for all stages of citrus (SANCO/321/2000 rev. 2) 

c

 FOCUS default value for this crop and BBCH code (SANCO/321/2000 rev. 2) 
– 212 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.3-2: Input parameter for spirotetramat and metabolites. 

Compound Parameter Value Remarks 

DegT50 [days] 0.23 Worst case, lab, SFO, normalized, n = 4 Spirotetramat 

Molecular weight [g mol-1] 373.45 

DegT50 [days] 2.64 

Worst case, lab (spirotetramat-enol degradation 

study), SFO recalculated from FOMC-DT90 divided by 

3.32, normalized, n = 4 

Maximum occurrence [%] 100.0 Unknown, worst case assumption 

Spirotetramatenol 

Molecular weight [g mol-1] 301.38 

DegT50 [days] 12.1 Worst case, lab (spirotetramat-enol degradation 

study), SFO, normalized, n = 4 

Maximum occurrence [%] 24.0 Spirotetramat-enol degradation study, lab 

Spirotetramatketohydroxy 

Molecular weight [g mol-1] 317.38 

DegT50 [days] 0.6 Worst case, lab, SFO, non-normalized, n = 3 

Maximum occurrence [%] 10.0 Soil photolysis, lab 4-Methoxycyclohexanone 

Molecular weight [g mol-1] 128.17 

Findings:

Table B.8.3-3: Calculated PECS values [mg kg-1] and TWAS values [mg kg-1] for spirotetramat and 

major metabolites in soil (multiple application). 

Spirotetramat Spirotetramatenol 

Spirotetramatketohydroxy 4-Methoxycyclohexanone Crop 

Days after 

last 

applicationa PECS

[mg kg-1] 

TWAS

[mg kg-1] 

PECS

[mg kg-1] 

TWAS

[mg kg-1] 

PECS

[mg kg-1] 

TWAS

[mg kg-1] 

PECS

[mg kg-1] 

TWAS

[mg kg-1] 

0 0.115 - 0.093 - 0.031 - 0.004 - 

1 0.006 0.036 0.072 0.082 0.029 0.030 0.001 0.003 

2 < 0.001 0.019 0.055 0.073 0.027 0.029 < 0.001 0.002

4 < 0.001 0.010 0.033 0.058 0.024 0.027 < 0.001 0.001

7 < 0.001 0.005 0.015 0.043 0.020 0.025 < 0.001 0.001

14 < 0.001 0.003 0.002 0.025 0.014 0.021 < 0.001 < 0.001 

21 < 0.001 0.002 < 0.001 0.017 0.009 0.018 < 0.001 < 0.001 

28 < 0.001 0.001 < 0.001 0.013 0.006 0.015 < 0.001 < 0.001 

42 < 0.001 0.001 < 0.001 0.008 0.003 0.012 < 0.001 < 0.001 

50 < 0.001 0.001 < 0.001 0.007 0.002 0.010 < 0.001 < 0.001 

Citrus 

100 < 0.001 0.001 < 0.001 0.004 < 0.001 0.005 < 0.001 < 0.001 

0 0.029 - 0.024 - 0.009 - 0.001 - 

1 0.001 0.009 0.018 0.021 0.008 0.008 < 0.001 0.001 

2 < 0.001 0.005 0.014 0.018 0.008 0.008 < 0.001 < 0.001 

4 < 0.001 0.002 0.008 0.015 0.007 0.008 < 0.001 < 0.001 

7 < 0.001 0.001 0.004 0.011 0.006 0.007 < 0.001 < 0.001 

14 < 0.001 0.001 < 0.001 0.006 0.004 0.006 < 0.001 < 0.001 

21 < 0.001 < 0.001 < 0.001 0.004 0.003 0.005 < 0.001 < 0.001 

28 < 0.001 < 0.001 < 0.001 0.003 0.002 0.004 < 0.001 < 0.001 

42 < 0.001 < 0.001 < 0.001 0.002 0.001 0.003 < 0.001 < 0.001 

50 < 0.001 < 0.001 < 0.001 0.002 < 0.001 0.003 < 0.001 < 0.001 

Leafy 

vegetables 

100 < 0.001 < 0.001 < 0.001 0.001 < 0.001 0.001 < 0.001 < 0.001 

a

 Last application always represents the worst case for all compounds 

Conclusion:

Calculated maximum PECS values for spirotetramat, spirotetramat-enol, spirotetramat-ketohydroxy and 4-

methoxy-cyclohexanone (the latter a soil photolysis metabolite) were 0.115, 0.093, 0.031 and 0.004 mg kg-1

, 

respectively, for use of 150 OD in citrus and 0.029, 0.024, 0.009 and 0.001 mg kg-1, respectively, for use of 

150 OD in leafy vegetables. 
– 213 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Comments (RMS):

• The notifier also presented PECS calculations for spirotetramat-MA-amide. Since this metabolite 

does not exceed 10 % of AR in soil and does not show a steady increase towards study termination, 

no PECS calculations are deemed necessary for this minor soil metabolite. 
– 214 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

B.8.6 Predicted environmental concentration in groundwater (PECGW) for the active 

substance and relevant metabolites (OECD Annex IIIA, 9.6) 

Reference: Predicted environmental concentrations of spirotetramat and its main soil 

metabolites in groundwater recharge (PECgw) based on calculations with 

FOCUS PEARL: Use in citrus in Europe 

Author(s), year: Röpke, B., 2006c 

Study/report number: M-277121-02-2, MEF-06/280, amended 12.06.2007 

Guideline(s): Calculations – Not applicable 

GLP: Calculations – Not applicable 

Deviations: Calculations – Not applicable 

Validity: Study considered acceptable 

and 

Reference: Predicted environmental concentrations of spirotetramat and its main soil 

metabolites in groundwater recharge (PECgw) based on calculations with 

FOCUS PEARL: Use in leafy vegetable in Europe 

Author(s), year: Röpke, B., 2006d 

Study/report number: M-277164-02-2, MEF-06/385, amended 12.06.2007 

Guideline(s): Calculations – Not applicable 

GLP: Calculations – Not applicable 

Deviations: Calculations – Not applicable 

Validity: Study considered acceptable 

and 

Reference: Predicted environmental concentrations of 4-methoxy cyclohexanone in 

groundwater recharge (PECgw) based on calculations with FOCUS PEARL 

Author(s), year: Röpke, B., 2007b 

Study/report number: M-294996-01-1/MEF-07/477 

Guideline(s): Calculations – Not applicable 

GLP: Calculations – Not applicable 

Deviations: Calculations – Not applicable 

Validity: Study considered acceptable 

Material and methods:

Predicted environmental concentrations of spirotetramat and the metabolites spirotetramat-enol, 

spirotetramat-ketohydroxy, spirotetramat-MA-amide and 4-methoxy-cyclohexanone (the latter a major soil

photolysis metabolite) in groundwater (PECGW, [μg L-1]) were calculated according to FOCUS guidance using 

FOCUS PEARL 3.3.3. 

The degradation pathway of spirotetramat in soil was implemented as a multi-compartment model into 

FOCUS PEARL 3.3.3 taking into account a simple first order-reversible binding (SFO-RB) approach for the 

metabolite spirotetramat-enol (Fig. B.8.6-1). Degradation of the parent and all other compounds followed 

SFO kinetics. 

The major soil photolysis metabolite 4-methoxy-cyclohexanone could not be adequately linked to the overall 

degradation model; therefore, 4-methoxy-cyclohexanone was modelled for groundwater risk assessment on 
– 215 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

the basis of a pseudo application (taking into account the maximum occurrence observed in the soil 

photolysis study and the molar ratio). 

The SFO-RB model, used for spirotetramat-enol, is conceptually similar to the kinetic sorption model 

implemented in FOCUS PEARL. The kinetic sorption model employed considers three phases, the dissolved 

phase, the equilibrium sorbed phase and the non-equilibrium sorbed phase (Figure B.8.6-2). The relation 

between dissolved and equilibrium sorbed phase is characterized by instantaneous equilibration between the 

concentrations in both phases and is described by the Freundlich isotherm. The transfer between the 

equilibrium phase and the non-equilibrium sorbed phase is described by a first order (SFO) reaction with the 

corresponding sorption rate kd. The ‘capacity’ of the non-equilibrium sorbed phase is characterized by the 

parameter fNE which is defined as the ratio between the Freundlich coefficients in the equilibrium phase and 

the non-equilibrium sorbed phase. The degradation constant in the equilibrium domain kt

, which is used for 

the estimation of the first order pseudo half life, is valid in connection with the kinetic model, only. Kinetic 

sorption and degradation parameters stated in Table B.8.6-2, which are required for groundwater modelling, 

were directly derived from the SFO-RB parameter (for more details refer to chapter ‘Aerobic degradation of 

relevant metabolites at 20 °C’, B.8.1.2.3). 

The SFO-RB/kinetic adsorption approach was also shown to adequately describe the behaviour of 

spirotetramat-enol observed in the column leaching study. 

Figure B.8.6-1: Multi-compartment model of spirotetramat and metabolites 

used for groundwater modelling (taking into account a SFO-RB approach for spirotetramat-enol). 

Spirotetramat (SFO) 

Spirotetramat-enol (mobile) 

Spirotetramat-ketohydroxy (SFO) 

Spirotetramat-MA-amide (SFO) 

Sink 

100 % 

26 % 74 % 

100 % 

100 % 

Spirotetramat-enol (protected) 

SFORB 
– 216 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Figure B.8.6-2: Concept of the equilibrium and non-equilibrium domain of the soil system 

(kinetic sorption model) implemented in FOCUS PEARL. 

Table B.8.6-1: Application data of spirotetramat applied as 150 OD formulation. 

Crop Citrus Leafy vegetablesa

Application rate [g ha-1] 288b72 

Number of applications 2 2 

Interval [days] 21 14 

BBCH code 71 – 78 42 - 43 

Crop interception [%] 70c70d

Application dates: 

 Châteaudun 

 Hamburg 

 Jokioinen 

 Kremsmünster 

 Piacenza 

 Porto 

 Sevilla 

 Thiva 

- 

- 

- 

- 

November 11th, 28th 

November 11th, 28th 

November 11th, 28th 

November 11th, 28th

Relative application date for all 

relevant scenarios 

(30 and 44 days after emergence) 

a

 Leafy vegetables not defined in FOCUS groundwater, ‘cabbage’ used as surrogate 

b Maximum application rate assuming 96 g ai ha-1 m-1 tree height (maximum tree height 3 m) 

c

 FOCUS default value for all stages of citrus (SANCO/321/2000 rev. 2) 

d

 FOCUS default value for this crop and BBCH code (SANCO/321/2000 rev. 2) 
– 217 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.6-2: Input parameter for spirotetramat and metabolites (all input parameter not mentioned in this table were set to default values). 

Compound Parameter Value Remarks 

Molecular weight [g mol-1] 373.45 Water solubility (20 °C, pH 7) [mg L-1] 29.9 Vapour pressure (20 °C) [Pa] 5.6 × 10-9KFOC [L kg-1] 281 Arithmetic mean, batch, n = 5 1/n 0.94 Arithmetic mean, batch, n = 5 DegT50 soil [days] 0.13 Geometric mean, lab, SFO, normalized, n = 4 

Spirotetramat 

Plant uptake factor 0.5 FOCUS default 

Molecular weight [g mol-1] 301.38 Water solubility (20 °C, pH 7) [mg L-1] 2700 Vapour pressure (20 °C) [Pa] 3.64 × 10-10 Unknown, estimate, US EPA (2000) KOC [L kg-1] 55 Arithmetic mean, column leaching study, n = 4 1/n 1.0 Unknown, worst case DegT50 soil [days] 0.03a Geometric mean, lab (spirotetramat-enol degradation study), kinetic sorption SFO according to the SFO-RB approach, normalized, n = 4 Formation fraction [0 ... 1] (from parent) 1.00 Unknown, worst case assumption kd [days-1] 0.016 Geometric mean, lab (spirotetramat-enol degradation study), SFO according to the SFO-RB approach, non-normalized, n = 4 fNE [-] 377b Arithmetic mean, lab (spirotetramat-enol degradation study), ratio according to the SFO-RB approach, non-normalized, n = 4 

Spirotetramatenol 

Plant uptake factor 0.5 FOCUS default 

Molecular weight [g mol-1] 317.38 Water solubility (20 °C, pH 7) [mg L-1] 288 Vapour pressure (20 °C) [Pa] 2.21 × 10-10 Unknown, estimate, US EPA (2000) KFOC [L kg-1] 63.7 Arithmetic mean, batch, n = 5 1/n 0.92 Arithmetic mean, batch, n = 5 DegT50 [days] 3.8 Geometric mean, lab (spirotetramat-enol degradation study), SFO, normalized, n = 4 Formation fraction [0 ... 1] (from spirotetramat-enol) 0.26 Arithmetic mean, lab (spirotetramat-enol degradation study), n = 4 

Spirotetramatketohydroxy 

Plant uptake factor 0.5 FOCUS default 

Molecular weight [g mol-1] 335.40 Water solubility (20 °C, pH 7) [mg L-1] 69.74 Vapour pressure (20 °C) [Pa] 1.56 × 10-11 Unknown, estimate, US EPA (2000) KFOC [L kg-1] 9.3 Arithmetic mean, batch, n = 5 

SpirotetramatMA-amide 

1/n 0.95 Arithmetic mean, batch, n = 5 
– 218 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Compound Parameter Value Remarks 

DegT50 [days] 1.0 Geometric mean, lab (spirotetramat-enol degradation study), SFO, normalized, n = 4 Formation fraction [0 ... 1] (from spirotetramat-ketohydroxy) 1.00 Set to 1.00 during kinetic evaluationPlant uptake factor 0.5 FOCUS default Molecular weight [g mol-1] 128.17 Water solubility (20 °C, pH 7) [mg L-1] 53200 Unknown, estimate, US EPA (2000) Vapour pressure (20 °C) [Pa] 70.8 Unknown, estimate, US EPA (2000) KFOC [L kg-1] 0 Unknown, worst case 1/n 0.9 Unknown, FOCUS default DegT50 [days] 0.6 Worst case, lab, SFO, non-normalized, n = 3 Maximum occurrence [% of AR] 10.0 Soil photolysis 

4-methoxy 

cyclohexanone 

Plant uptake factor 0.5 FOCUS default 

a As it is not possible to use a DT50 value below 0.1 d in PEARL 3.3.3, a DT50 of 0.1 days was used instead of the calculated value of 0.03 days, which represents a worst case for spirotetramat-enol in 

this case 

b Arithmetic mean value of 377 substituted with 99 (upper limit in PEARL 3.3.3) 
– 219 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Findings:

Table B.8.6-3: PECGW values [μg L-1] of spirotetramat and its soil metabolites from use in citrus and 

leafy vegetables in Europe calculated with FOCUS PEARL 3.3.3. 

Crop Scenario Spirotetramat Spirotetramatenol 

Spirotetramatketohydroxy SpirotetramatMA-amide 

4-methoxy 

cyclohexanone 

Piacenza < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 

Porto < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 

Sevilla < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 

Citrus 

Thiva < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 

Châteaudun < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 

Hamburg < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 

Jokioinen < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 

Kremsmünster < 0.001 < 0.001 < 0.001 < 0.001 < 0.001

Porto < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 

Sevilla < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 

Leafy 

vegetables 

Thiva < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 

Conclusion:

The leaching simulations resulted in PECGW values below 0.1 μg L-1 for spirotetramat and its soil metabolites 

for all intended uses and all relevant FOCUS scenarios. The risk for groundwater leaching is considered low. 

Comments (RMS):

• The geometric mean soil DT50 of spirotetramat-ketohydroxy should be 3.9 days instead of 3.8 days 

used for PEC calculations. However, this minor difference is not considered to have a significant 

impact onto the risk assessment of spirotetramat-ketohydroxy. Therefore, the groundwater risk 

assessment is considered acceptable at all. 

• It may be annotated, that degradation rates and formation fractions of spirotetramat-ketohydroxy and 

spirotetramat-MA-amide obtained from the more simplistic degradation schemes SFO  SFO 

SFO  SFO, SFO  FOMC  SFO  SFO or SFO  DFOP  SFO  SFO (all lower tier 

approaches) are almost identical to the data obtained from the higher tier approach SFO  SFO-RB 

 SFO  SFO, applied in the study above (also refer to chapter ‘Aerobic degradation of relevant 

metabolites at 20 °C’, B.8.1.2.3). This is reasonable since the release of spirotetramat-ketohydroxy 

from spirotetramat-enol as its precursor is almost exclusively attributed to the initial and fast 

degradation phase of the (mobile) spirotetramat-enol fraction. The release of spirotetramatketohydroxy from the second and slower degradation phase of the strongly bound (immobile) 

spirotetramat-enol fraction is considerably lower. In this respect, a reasonable 1st tier groundwater 

risk assessment may be solely based on obtained SFO degradation rates for all, the parent and all 

metabolites including spirotetramat-enol. The ‘remaining’ strongly bound spirotetramat-enol fraction 

in the soil (representing the latter phase in the FOMC or DFOP kinetics model, which is per se not 

adequately addressed using SFO kinetics) is neither considered to be mobile (no potential for 

leaching as demonstrated in the column leaching study) nor considered to significantly attribute to 

the further release of metabolites owing to its rather slow degradation rate. 
– 220 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

B.8.7 Predicted environmental concentration in surface water (PECSW) and sediment 

(PECSED) for the active substance and relevant metabolites (OECD Annex IIIA, 9.7, 9.8) 

Reference: Predicted environmental concentrations of spirotetramat and its main 

metabolites in surface water and sediment (PECSW/SED) calculated according 

to FOCUS: Use in citrus in Europe 

Author(s), year: Röpke, B., 2006e 

Study/report number: M-277190-01-1, MEF-06/281 

Guideline(s): Calculations – Not applicable 

GLP: Calculations – Not applicable 

Deviations: Calculations – Not applicable 

Validity: Study considered acceptable 

and 

Reference: Predicted environmental concentrations of spirotetramat and its main 

metabolites in surface water and sediment (PECSW/SED) calculated according 

to FOCUS: Use in leafy vegetables in Europe 

Author(s), year: Röpke, B., 2006f 

Study/report number: M-277176-01-1, MEF-06/386 

Guideline(s): Calculations – Not applicable 

GLP: Calculations – Not applicable 

Deviations: Calculations – Not applicable 

Validity: Study considered acceptable 

Material and methods:

Predicted environmental concentrations in surface water (PECSW) and sediment (PECSED) for spirotetramat, 

spirotetramat-enol, spirotetramat-ketohydroxy, 4-methoxy-cylcohexanone and 4-methoxy-cyclohexylaminocarboxylic acid (the latter two major in water photolysis and, partly, in soil photolysis) were calculated 

according to FOCUS guidance based on FOCUS surface water tools STEPS 1 – 4 (for metabolites STEPS 1 

and 2, only). 

At FOCUS surface water STEP 4 (for use in citrus only), mitigation of drift deposition was achieved by

introducing buffer zones (vegetation filter strips). Reduced drift deposition based on a 5-m-buffer zone (Table 

B.8.7-1) was calculated using the FOCUS drift calculator. No mitigation of runoff or drainage was assumed. 
– 221 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.7-1: Application data of spirotetramat applied as 150 OD formulation. 

Crop Citrus Leafy vegetables 

Application rate [g ha-1] 288a72 

Number of applications 2 2 

Interval [days] 21 14 

BBCH code 71 – 78 42 - 43 

Crop interception [%] 

 FOCUS STEP 1 

 FOCUS STEP 2 

 FOCUS STEP 3 & 4 

None 

70b (full canopy) 

Calculated by the model 

None 

70c (full canopy) 

Calculated by the model 

Drift deposition [%] 

 FOCUS STEP 1, 2 & 3 

 FOCUS STEP 4 (5 m buffer zone)

 Ditch 

 Stream 

Default values 

7.51 

9.01e

Default values 

Not calculated 

Region/Scenario: 

 FOCUS STEP 1 

 FOCUS STEP 2 

 FOCUS STEP 3 & 4 

Not defined 

South EU 

D6 (Thiva), R4 (Roujan) 

Not defined 

South EU, North EU 

D3 (Vredepeel, 1st), D4 (Skousbo), 

D6 (Thiva), R1 (Weiherbach, 1st), 

R2 (Porto, 1st), R3 (Bologna, 1st), 

R4 (Roujan, 1st) 

Application timing/window: 

 FOCUS STEP 1 

 FOCUS STEP 2 

 FOCUS STEP 3 & 4 

Not defined 

October to February 

 Start: D6: November 1st 

 R4: November 1st 

Appl. window: 30 + 21 days 

 Appl. date calculated by PATd 

Not defined 

March to Mayf

 Start: D3: May 13th 

 D4: July 20th 

 D6: September 23rd 

 R1: May 8th 

 R2: April 23rd 

 R3: March 25th 

 R4: March 25th

 Appl. window: 30 + 14 days 

 Appl. date calculated by PATd

RunOff/Drainage: 

 FOCUS STEP 1 & 2 

 FOCUS STEP 3 

 FOCUS STEP 4 

Default values 

Modelled by PRZM and MACRO 

Modelled by PRZM and MACRO, 

no runoff/drainage mitigation 

assumed 

Default values 

Modelled by PRZM and MACRO 

Not calculated 

a Maximum application rate assuming 96 g ai ha-1 m-1 tree height (maximum tree height 3 m) 

b

 FOCUS default value for all stages of citrus (SANCO/4802/2001-rev.2) 

c

 FOCUS default value for this crop and BBCH code (SANCO/4802/2001-rev.2) 

d

 PAT denotes pesticide application timer 

e

 Number stated corrected for additional indirect drift input from the upstream catchment (i.e. 20 %) 

f

 In respect to runoff /drainage, the application timing ‘March to May’ is worst case for South EU, for North EU this application timing is 

representative for the indented use
– 222 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Table B.8.7-2: Input parameter for spirotetramat and metabolites (input parameter not mentioned in this table were set to default values). 

Value Compound Parameter STEP 1 & 2 STEP 3 & 4 Remarks 

Molecular weight [g mol-1] 373.45 Water solubility (20 °C, pH 7) [mg L-1] 29.9 Vapour pressure (20 °C) [Pa] - 5.6 × 10-9KFOC [L kg-1] 281 Arithmetic mean, batch, n = 5 1/n - 0.94 Arithmetic mean, batch, n = 5 DegT50 soil [days] 0.13 Geometric mean, lab, SFO, normalized, n = 4 DegT50 water [days] 0.78 Geometric mean, entire system, SFO, n = 2 DegT50 sediment [days] 0.78 1000 STEP 1 & 2: Geometric mean, entire system, SFO, n = 2 STEP 3 & 4: Worst case default value 

Spirotetramat 

DegT50 entire system [days] 0.78 - Geometric mean, entire system, SFO, n = 2 

Molecular weight [g mol-1] 301.38 Water solubility (20 °C, pH 7) [mg L-1] 2700 KOC [L kg-1] 55 Arithmetic mean, column leaching study, n = 4 DegT50 soil [days] 1.16 Geometric mean, lab (spirotetramat-enol degradation study), SFO recalculated from FOMC-DT90 divided by 3.32, normalized, n = 4 DegT50 water [days] 47.3 Geometric mean, entire system, SFO, n = 2 DegT50 sediment [days] 47.3 Geometric mean, entire system, SFO, n = 2 DegT50 entire system [days] 47.3 Geometric mean, entire system, SFO, n = 2 Maximum occurrence soil [%] 100.0 Not known, worst case assumption 

Spirotetramatenol 

Maximum occurrence entire system [%] 97.5 

Not 

performed 

Molecular weight [g mol-1] 317.38 Water solubility (20 °C, pH 7) [mg L-1] 288 KFOC [L kg-1] 63.7 Arithmetic mean, batch, n = 5 DegT50 [days] 3.8 Geometric mean, lab (spirotetramat-enol degradation study), SFO, normalized, n = 4 DegT50 water [days] 1000 No degradation observed, worst case default value DegT50 sediment [days] 1000 No degradation observed, worst case default value DegT50 entire system [days] 1000 No degradation observed, worst case default value Maximum occurrence soil [%] 24.0 

Spirotetramatketohydroxy 

Maximum occurrence entire system [%] 40.5 

Not 

performed 

Molecular weight [g mol-1] 128.17 Water solubility [mg L-1] 53200 Unknown, estimate, US EPA, 2000aKOC [L kg-1] 2.6 Unknown, estimate, US EPA, 2000a

4-Methoxy 

cyclohexanone 

DegT50 [days] 0.6 

Not 

performed 

Worst case, lab, SFO, non-normalized, n = 3 
– 223 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Value Compound Parameter STEP 1 & 2 STEP 3 & 4 Remarks 

DegT50 water [days] 1000 No degradation observed, worst case default value DegT50 sediment [days] 1000 No degradation observed, worst case default value DegT50 entire system [days] 1000 No degradation observed, worst case default value Maximum occurrence soil [%] 10.0a Soil photolysis study Maximum occurrence entire system [%] 17.5 Phototransformation study in natural water Molecular weight [g mol-1] 173.21 Water solubility [mg L-1] 26570 Unknown, estimate, US EPA, 2000aKOC [L kg-1] 10 Unknown, estimate, US EPA, 2000aDegT50 [days] 1000 Unknown, not observed in soil, value does not effect the calculation DegT50 water [days] 1000 No degradation observed, worst case default value DegT50 sediment [days] 1000 No degradation observed, worst case default value DegT50 entire system [days] 1000 No degradation observed, worst case default value Maximum occurrence soil [%] 0.0b Not observed in soil 

4-Methoxycyclohexylaminocarboxylic 

acid 

Maximum occurrence entire system [%] 11.3 

Not 

performed 

Phototransformation study in natural water 

a Set to 0.0 % of AR in the original study, re-calculated by the RMS based on 10.0 % of AR. See comments. b At FOCUS STEP 1 & 2 set to 1 × 10-10 (zero value not accepted). 
– 224 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Findings:

Table B.8.7-3: Predicted environmental concentrations of spirotetramat and metabolites in surface water (PECSW, [μg L-1]) and sediment (PECSED, 

[μg kg-1]) after use in citrus following FOCUS surface water STEPS 1 - 4. 

FOCUS surface water STEP 1 STEP 2 STEP 3 STEP 4 (5-m-buffer zone) Compartment Region/Scenario - South EU D6 - Ditch R4 - Stream D6 - Ditch R4 - Stream 

Spirotetramat 84.9 11.6 8.43 6.51 5.86 nc Spirotetramat-enol 168 15.6 nc nc nc nc Spirotetramat-ketohydroxy 46.5 8.59 nc nc nc nc Methoxy cyclohexanone 8.38 1.39 nc nc nc nc 

Surface water 

(PECSW) 

[μg L-1] 

Methoxy cyclohexylaminocarboxylic acid 1.58 1.21 nc nc nc nc 

Spirotetramat 196 6.53 4.16 0.753 2.92 nc Spirotetramat-enol 90.2 8.00 nc nc nc nc Spirotetramat-ketohydroxy 29.1 5.34 nc nc nc nc Methoxy cyclohexanone 0.218 0.036 nc nc nc nc 

Sediment 

(PECSED) 

[μg kg-1] 

Methoxy cyclohexylaminocarboxylic acid 0.156 0.119 nc nc nc nc 

nc denotes not calculated Table B.8.7-4: Predicted environmental concentrations of spirotetramat and metabolites in surface water (PECSW, [μg L-1]) and sediment (PECSED, 

[μg kg-1]) after use in leafy vegetable following FOCUS surface water STEPS 1 - 3. 

FOCUS surface water STEP 1 STEP 2 STEP 3 

Compartment Region/Scenario - North EUa South EU D3 ditch D4 pond D4 stream D6 ditch R1 pond R1 stream R2 stream R3 stream R4 stream

Spirotetramat 18.1 0.585 0.585 0.399 0.0129 0.324 0.398 0.0129 0.261 0.350 0.368 0.261 Spirotetramat-enol 37.1 0.850 0.950 nc nc nc nc nc nc nc nc nc Spirotetramat-ketohydroxy 9.48 0.519 0.662 nc nc nc nc nc nc nc nc nc Methoxy cyclohexanone 1.72 0.071 0.071 nc nc nc nc nc nc nc nc nc 

Surface water 

(PECSW) 

[μg L-1] 

Methoxy cyclohexylaminocarboxylic acid 0.069 0.061 0.061 nc nc nc nc nc nc nc nc nc 

Spirotetramat 49.1 0.328 0.328 0.119 0.007 0.021 0.108 0.006 0.033 0.026 0.071 0.034 Spirotetramat-enol 20.1 0.452 0.505 nc nc nc nc nc nc nc nc nc Spirotetramat-ketohydroxy 6.01 0.324 0.415 nc nc nc nc nc nc nc nc nc Methoxy cyclohexanone 0.043 0.002 0.002 nc nc nc nc nc nc nc nc nc 

Sediment 

(PECSED) 

[μg kg-1] 

Methoxy cyclohexylaminocarboxylic acid 0.007 0.006 0.006 nc nc nc nc nc nc nc nc nc 

nc denotes not calculated a Calculated by the RMS 
– 225 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

Conclusion:

Maximum PECSW values of spirotetramat in surface water after use in citrus were calculated to be 84.9, 11.6, 

8.43 and 5.86 μg L-1 at FOCUS surface water STEP 1, 2, 3 and 4 (STEP 4 considering drift mitigation only, 

buffer zone 5 m). Following application in leafy vegetables, maximum PECSW of spirotetramat were 

calculated to be 18.1, 0.59 and 0.40 μg L-1 at STEP 1, 2 and 3 (no STEP 4 calculation conducted). 

Maximum PECSW for the metabolites spirotetramat-enol, spirotetramat-ketohydroxy, spirotetramat-MAamide, 4-methoxy-cylcohexanone and 4-methoxy-cyclohexylaminocarboxylic acid were calculated to be 

15.6, 8.59, 1.39 and 1.21 μg L-1, respectively, at FOCUS surface water STEP 2 after use in citrus and 0.95, 

0.66, 0.071 and 0.061 μg L-1, respectively, after use in leafy vegetables. 

In sediment, maximum PECSED values of spirotetramat after use in citrus were calculated to be 196, 6.53, 

4.16 and 2.92 μg kg-1 at FOCUS surface water STEP 1, 2, 3 and 4 (STEP 4 considering drift mitigation only, 

buffer zone 5 m). Following application in leafy vegetables, maximum PECSW of spirotetramat were 

calculated to be 49.1, 0.33 and 0.12 μg kg-1 at STEP 1, 2 and 3 (no STEP 4 calculation conducted). 

Maximum PECSED values for the metabolites spirotetramat-enol, spirotetramat-ketohydroxy, 4-methoxycylcohexanone and 4-methoxy-cyclohexyl-aminocarboxylic acid were calculated to be 8.00, 5.34, 0.036 and 

0.12 μg kg-1, respectively, at FOCUS surface water STEP 2 after use in citrus and 0.51, 0.42, 0.002 and 

0.006 μg kg-1, respectively, after use in leafy vegetables. 

Comments (RMS):

• The geometric mean soil DT50 of spirotetramat-ketohydroxy should be 3.9 days instead of 3.8 days 

used for PEC calculations. However, this minor difference is not considered to have a significant 

impact onto the risk assessment of spirotetramat-ketohydroxy. Therefore, the surface water and 

sediment risk assessment is considered acceptable at all. 

• In the original study report, maximum occurrence of 4-methoxy-cyclohexanone in soil was set to 

0.0 % of AR. However, since 4-methoxy-cyclohexanone is major in the soil photolysis (10.0 % of 

AR), the PECSW/SED were re-calculated by the RMS. 

• In the original study report, no results on application on leafy vegetables in North-EU at FOCUS 

surface water STEP 2 were presented. These data were calculated and added by the RMS. 
– 226 – 

Spirotetramat – Volume 3, Annex B.8, Fate and behaviour in the environment April 2008

B.8.9 Predicted environmental concentration in the air (PECA) (OECD Annex IIIA, 9.9) 

Based on the low vapour pressure of spirotetramat and spirotetramat-enol (< 10-9 Pa) no significant transfer 

into the atmosphere is expected to occur. In the eventuality that spirotetramat or spirotetramat-enol enters 

the atmosphere, both compounds are expected to rapidly degradate owing to reaction with OH radicals 

(atmospheric half-life < 2 hrs based on Atkinson calculation).