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Environmental fate & pathways

Adsorption / desorption

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Description of key information

Adsorption to solid soil phase is not expected. 

Key value for chemical safety assessment

Additional information

In Article 13 of Regulation (EC) No 1907/2006, it is laid down that information on intrinsic properties of substances may be generated by means other than tests, provided that the conditions set out in Annex XI (of the same Regulation) are met. Furthermore according to Article 25 of the same Regulation testing on vertebrate animals shall be undertaken only as a last resort.

 

According to Annex XI of Regulation (EC) No 1907/2006 (Q)SAR results can be used if (1) the scientific validity of the (Q)SAR model has been established, (2) the substance falls within the applicability domain of the (Q)SAR model, (3) the results are adequate for the purpose of classification and labeling and/or risk assessment and (4) adequate and reliable documentation of the applied method is provided.

 

For the assessment of the present compund (Q)SAR results were used for adsorption/desorption. The criteria listed in Annex XI of Regulation (EC) No 1907/2006 are considered to be adequately fulfilled and therefore the endpoint(s) sufficiently covered and suitable for risk assessment.

 

Therefore further experimental studies on adsorption/desorption are not provided.

The adsorption potential of the compound was assessed with two different QSAR calculations. The KOCWIN v2.00 model integrated in the US EPA's EPISuite v4.11 comprises two submodels to estimate the Koc/logKoc. The first submodel uses the molecular connectivity index (MCI) as the only parameter to estimate the Koc/logKoc. The second method estimates the Koc/logKoc by correlation to the logKow. The compound has very low solubilities in water and octanol, respectively. This results in a very low logKow of 0.3 which contrasts the estimated logKow of EPISuite of 10.28. Therefore, the experimental data was used as input parameter in this submodel.

The estimated logKoc values of the two submodels highly differed. However, the model which uses the experimentally derived logKow was regarded as the appropriate model because of the experimetal logKow value. The result of the MCI submodel was not taken into account in the assessment of the adsorption potential.

In conclusion, adsorption to the solid soil phase is not expected.