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Partition coefficient

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Description of key information

Partition coefficient [trimethylsilane]: 2.2 at 20°C (QSAR)
Partition coefficient [trimethylsilanol]: 1.19 at 25°C (OECD 107)
Log Kaw [trimethylsilanol]: -2.77± 0.1 at 25± 0.3°C

Key value for chemical safety assessment

Log Kow (Log Pow):
at the temperature of:
20 °C

Additional information

A log Kow value of 2.2 at 20°C was determined for the substance using a validated QSAR estimation method. The result is considered to be reliable.

In contact with water, trimethylsilane hydrolyses slowly to form trimethylsilanol and hydrogen.

Trimethylsilanol has a measured log Kow value of 1.19 at 25 ± 0.5°C and pH 7.1 in accordance with relevant test method and in compliance with GLP. In another disregarded study, a log Kow of 1.62 at 40°C and pH 7 was determined for trimethylsilanol using HPLC method in accordance with OECD 117 test method. The result was disregarded because some necessary corrective adjustments that would be needed to validly interpret the result were not conducted. In a non-standard study, dimensionless coefficients of air/water (Kaw), octanol/air (Koa) and octanol/water partition (Kow) of trimethylsilanol were determined using a custom-made glass apparatus. The apparatus allowed for the establishment of octanol/air/water three phase equilibrium at a temperature range of 5 -35°C. Measured values of log Kow = 1.22 ± 0.13, log Kaw = -2.77 ± 0.10 and log Koa = 4.01 ± 0.04 and 25± 0.3°C were obtained for trimethylsilanol.