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Physical & Chemical properties

Partition coefficient

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Link to relevant study record(s)

Description of key information

A Log Pow value of minus 9.8 has been obtained by calculation (Safepharm Laboratories (1997).
Indeed THPS main ingredient is infinitely soluble in water and is an ionised substance.
Log Pow measurements by the HPLC method and by the shake flask method are not applicable to substances which have a log Pow < 0 and < -2 respectively. Therefore only a calculated value can be provided.
Effect of pH (5 to 9) and temperature is not expected as THPS main ingredient is ionised and infinitely soluble in water at these pH and at environmentally relevant temperatures.

Key value for chemical safety assessment

Log Kow (Log Pow):
-9.8

Additional information

One non-GLP study performed according to standard guideline was disregarded (reliability 3) because the HPLC method used is not applicable to substances which have a log Pow<0.

One non-GLP study performed according to a scientifically valid shake flask method was disregarded (reliability 3) because the method is not applicable to substances of very high solubility in water and no result was obtained in the study report.

Log Pow was calculated with the KOWWIN program based on the method described in the literature (HOWARD P.H. and MEYLAN W.M.,  J. Pharm. Sci., 84 (1) : 83-92, 1995). This accepted calculation method gives a log P = - 9.8 for THPS, which is then considered to have no potential for bioaccumulation.