Octamethylcyclotetrasiloxane

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Principles of method if other than guideline:

Equilibration by slow-stirring (pure liquid substance in contact with distilled water).

GLP compliance:

no

Type of method:

other: Equilibration by slow-stirring

Water solubility:

0.056 mg/L

Temp.:

23 °C

pH:

ca. 7

Details on results:

Stable: no
Degradation products: yes
Degradation products (CAS No./EC No./EINECS Name): 1066-42-8 213-915-7 dimethylsilanediol

Water solubility = 56.2 ug L-1  (190 x 10-9 mol L-1) at 23 °C

Conclusions:

Interpretation of results: insoluble (< 0.1 mg/L)
A water solubility value of 0.0562 mg/L was determined at 23°C in a reliable study conducted according to generally accepted scientific principles.

Description of key information

Water solubility [octamethylcyclotetrasiloxane]: 0.056 mg/l at 23°C

Key value for chemical safety assessment

Water solubility:

0.056 mg/L

at the temperature of:

23 °C

Additional information

Two reliable measured values for the solubility of the registration substance in freshwater are available. A water solubility value of 0.056 mg/l at 23°C was determined for the substance using equilibration by the slow-stirring method. The result is considered to be reliable and is selected as key study. This value is supported by a measure water solubility of 0.07 mg/l at 25°C using a relevant test method. The key study was selected as it is the most recent study and is in line with the UK RAR. In a secondary source to which reliability could not be assigned, a water solubility of 0.02 mg/l at 25°C was reported for the substance.

In synthetic seawater, the substance has a measured solubility of 0.033 mg/l at 25°C.