Dioctyltin oxide

Biodegradation in water and sediment: simulation tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: sediment simulation testing

Remarks:

OECD 308: Aerobic and Anaerobic Transformation in Aquatic Sediment Systems

Data waiving:

study technically not feasible

Justification for data waiving:

other:

Justification for type of information:

Expert Statement given by Study Director of GLP ecotox studies
-see attachment

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 308 (Aerobic and Anaerobic Transformation in Aquatic Sediment Systems)

Deviations:

yes

Remarks:

see free text

Principles of method if other than guideline:

study technical not feasible:
Sediment simulation testing as well as soil simulation testing were waived.
The low water solubility of the test item (<< 15µg/L) impairs / inhibits sediment simulation testing. No aqueous stock solution can be prepared for administering the test item to the overlying surface water in the study design of the sediment simulation test (OECD308). The test item is only soluble in boiling xylene. Xylene itself is readily biodegradable (registration dossier xylene, ECHA) and is therefore in concurrence to the biodegradation of the test item. Furthermore, the amount of carbon from the solvent is in excess compared to the carbon of the test item in the test system.

GLP compliance:

no

Remarks:

justification by laboratory why study technical not feasible:

Radiolabelling:

not specified

Oxygen conditions:

not specified

Inoculum or test system:

not specified

Duration of test (contact time):

0 h

Remarks on result:

not determinable

Remarks:

study technical not feasible

Key result

Remarks on result:

not determinable

Remarks:

study technical not feasible

Key result

Remarks on result:

not determinable

Remarks:

study technical not feasible

Mineralization rate (in CO2):

0 h-1

Other kinetic parameters:

other: study technical not feasible

Transformation products:

not specified

Evaporation of parent compound:

not specified

Volatile metabolites:

not specified

Residues:

not specified

Validity criteria fulfilled:

not applicable

Conclusions:

study technical not feasible

Reference 2

Endpoint:

biodegradation in water and sediment: simulation tests

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1976

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: study evaluated by US Office of Naval Research as valid

Qualifier:

no guideline available

Principles of method if other than guideline:

Details classified by US Department of the Navy, For details contact study owner

GLP compliance:

no

Radiolabelling:

yes

Oxygen conditions:

other: not relevant, other mechanism

Inoculum or test system:

other: not relevant, other mechanism

Duration of test (contact time):

> 0 - < 4 wk

Key result

Compartment:

natural water: freshwater

DT50:

3.25 d

St. dev.:

0

Type:

not specified

Temp.:

20 °C

Remarks on result:

other: microbial degradation

Mineralization rate (in CO2):

1 other: not relevant, C14

Other kinetic parameters:

other: rate sonstat: : 0.213 /day

Transformation products:

yes

No.:

#1

No.:

#2

Validity criteria fulfilled:

yes

Conclusions:

Degradation of Dioctyltin in the environment by elimination of octly groups

Description of key information

Study waiver OECD 308: Aerobic and Anaerobic Transformation in Aquatic Sediment Systems is technically not feasable. Further biotic degradation tests were considered unnecessary. The substance is considered to be of no immediate concern to the environment and the available data were found to be adequate for classification and labelling purposes and PBT assessment. Adaptations from the standard data requirements were submitted to address the individual endpoints.

Key value for chemical safety assessment

Half-life in freshwater:

3.25 d

at the temperature of:

20 °C