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Physical & Chemical properties

Partition coefficient

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Description of key information

OECD 117, GLP, key study, validity 2:
Log Pow = 3.1-3.2.
QSAR model, VCClab, supporting study, validity 4:
Average log Kow = 3.88 +/- 0.43.

Key value for chemical safety assessment

Log Kow (Log Pow):
3.2
at the temperature of:
55 °C

Additional information

One key study is available, performed according to OECD Guideline 117 with GLP statement, to determine the partition coefficient (Log Pow) of the test item by applying the HPLC method (Gancet, 2011). The test item used in this study has a purity of 52.5% in diisopropylbenzene. The temperature during the analytical sequence was 55 +/- 0.5°C. The pH of the mobile phase was 7.1. All validity criteria were fulfilled. However, during the analysis, 7 peaks were detected for the test item. The mass spectrometry profile confirmed that the main UV peaks observed (peaks 4 and 5) correspond to the test item. The retention time = 1.80 and 1.92 min, corresponding to log Pow = 3.1 and 3.2 respectively. As a non specific detector was used, no guarantee about respective proportions of components is be provided, nor attempt of identification of peaks. This study is assessed as reliable with restriction.

To support this result, the partition coefficient of the test substance was estimated using a QSAR model: VCClab. This tool gives access on its website to a friendly-user java interface that easily calculated the log Pow of a substance using nine different QSARs including KOWWIN. It automatically calculates the average log Pow with the standard error. No data is available with regard to validation parameters according to OECD principles. Results for the test item ranged from 3.32 to 4.63, with an average log Kow = 3.88, and a standard deviation of +/- 0.43 unit (based on eight QSARs results).

In conclusion, in spite of a non specific detector in the experimental study, the log Pow result is in agreement with QSAR.