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Physical & Chemical properties

Partition coefficient

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Description of key information

log Kow (constituents of the substance): >7.2 at 35°C and pH 7.3 (measured)
log Kow (constituents): 6.58 - >9.0 at 20°C (QSAR)

Key value for chemical safety assessment

Additional information

The substance is a hydrocarbon UVCB. Standard tests for this endpoint are intended for single substances and are not appropriate for this complex substance. However, this endpoint is characterised using quantitative structure property relationships for representative hydrocarbon structures that comprise the hydrocarbon blocks used to assess the environmental risk of this substance with QSAR software (see Section 13).

The log Kow of the constituents of the substance have been measured using the HPLC method in accordance with OECD 117 Test Method and in compliance with GLP. The n-octanol/water partition coefficients of the constituents were determined to be >1.58 x 107 (log10 Pow >7.2) at 35°C and pH 7.3. The study was considered to be reliable but the results are not useful for chemical safety assessment.

As supporting information, log Kow for individual constituents of Hydrocarbons, C15-C19, n-alkanes, isoalkanes, <2% aromatics have been predicted using a separately validated QSAR estimation method. The prediction method uses a fragment method and log Kow increases with increasing carbon number. The prediction domain covers carbon chain length in the range C1-C18 carbon atom, it is therefore expected that log Kow for longer chain length (i.e. greater than C18) compounds will be greater than the predicted value of 9.18 for C18 atom. The individual constituents of the substance have predicted log Kow values in the range 6.58 - >9 at 20°C.