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Physical & Chemical properties

Partition coefficient

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Description of key information

Key study: Spruit & Schilt (2003): -2.18 ± 0.17 (22.0 ± 1.0 °C) 

Key value for chemical safety assessment

Log Kow (Log Pow):
-2.18
at the temperature of:
22 °C

Additional information

The key study was a reliable Klimisch 1 study, conducted in accordance with OECD 117 guideline and EU guidelines and to GLP standard. The log partition coefficient n-octanol/water (log Pow) was determined to be -2.18 ± 0.17 (22.0 ± 1.0 °C).However, in water, DMTC undergoes rapid degradation by hydrolysis and is expected to hydrolyze within minutes. DMTC has sufficient water solubility that it can be studied in water using analytical methods that involve derivatization. This analysis method only measures the amount of the alkyltin moiety, but cannot identify the other ligands attached to the tin. Further, low levels of impurities may be present, even in a high purity organotin substance. These impurities often are more soluble in water than the named substance and confound the measurement of water solubility of the named substance to a significant degree. Thus, the reported value may not be due entirely to the named substance and any subsequent use of the partition coefficient to predict environmental behavior of the named substance must carefully consider the limitations inherent in the measurement of this parameter

The supporting studies range from a log Pow of -2.18 to -3.1, with the exception of one outlier from a QSAR method (Log Pow -1.056), which can be ignored on the basis that the calculation method used has not been fully validated for substances containing a metal ion.