Dibutyltin dichloride

Partition coefficient

Description of key information

No determination was performed using the shake-flask method, designed to be compatible with Method 107 of the OECD Guidelines for Testing of Chemicals, 27 July 1995. 
During preliminary investigations for the water solubility test, it was concluded that the test item hydrolysed within one hour of contact with water. Substances which hydrolyse rapidly in contact with water are not suitable for determination of using Method 107. Estimation using the ratio of the solubility of the test item in n-octanol and water would also be unreliable due to the rapid hydrolysis of the test item in the water. The partition coefficient determination using the HPLC method, Method 117 of the OECD Guidelines for Testing of Chemicals, was unsuitable since organometallic materials are known to react with HPLC columns.

Additional information

The study was considered to be not technically feasible according to the information provided in the Butler & White, 2010 study due to rapid hydrolyses of the test subtsance, as demonstrated in a water solubility study.

The following supporting studies are also available:

- In the Tsuda et al, 1986 paper, the Log Pow was calculated to be 0.97 ± 0.017.

A reliability rating of 4 was assigned, according to the criteria of Klimisch, 1997 as the method of analysis involved derivatization. This method only measures the amount of the alkyltin moiety, DBT, present and does not identify the other ligands attached to the tin. The low solubility and hydrolysis chemistry of these compounds present significant challenges to measuring the organotins in aqueous solution. None of the current analytical methods (e.g., alkyl or hydride derivatization) are acceptable for quantifying the resulting products of hydrolysis, as the parent compound, soluble impurities, and hydrolysis products will be derivatized to the same final tetraalkyltin or alkyltin hydride compound and there can be no differentiation between starting material and hydrolysis products. Therefore, the reported value may be influenced by the presence of more water-soluble impurities or hydrolysis products. The influence of impurities is not sufficiently documented.

- In the KEMI report, 1994 the Log Pow was calculated to be 0.05.

A reliability rating of 4 was assigned, according to the criteria of Klimisch, 1997 as the infomation was obtained from a secondary source.

- EPISuite v4.0 - KOWWIN version 1.67 estimates the log Pow to be 1.89.

A reliability rating of 4 was assigned, according to the criteria of Klimisch, 1997 as the value was derived using calculation method software.

Current versions of EPIWIN, developed by Syracuse Research Corporation, have not been validated for chemicals that contain metals in their molecular structure; therefore, the estimated values derived from the EPIWIN models should be used with caution however, as a value for Log Pow needs to be used for the risk assessment this data was considered to be the most appropriate.