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Environmental fate & pathways

Adsorption / desorption

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Description of key information

Adsorption to the solid soil phase is not to be expected.

Key value for chemical safety assessment

Additional information

QSAR-disclaimer

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 (diethylamino)acetonitrile (Q)SAR results were used for the estimation of the adsorption potential. 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 the adsorption potential are not provided.

 

Assessment of adsorption potential:

The Koc of (diethylamino)acetonitrile (CAS 3010-02-4) was estimated using the log Kow and MCI method of KOCWIN v2.00 implemented in EPI Suite v4.11. Both estimates refer to the uncharged molecule (BASF SE, 2015):

- Using the Molecular Connectivity Index (MCI), which is regarded as more reliable compared to the log Kow method, the log Koc for the uncharged molecule was estimated to be 1.3 (Koc = 19.9 L/kg; substance within the applicability domain of the model).

- Using the log Kow method the log Koc was estimated to be 1.6 (Koc = 35.5 L/kg), based on the calculated log Kow of 0.54 (estimated by KOWWIN v.1.68 implemented in Episuite v4.11). The substance was within the applicability domain of the model.

However, a pKa value of 4.55 indicates that the molecule will primarily exist as an anion in the environment. The adsorption of molecules to soils containing organic carbon and clay is generally influenced by their degree of ionization. As the KOCWIN-model does not consider the ionic structure of molecules, estimations of the adsorption to organic carbon by this model only refers to the uncharged molecule. In a calculation conducted according Franco & Trapp (2008, 2009 & 2010), a pH-corrected log Koc value of 1.59 (charged molecule at pH 7) was calculated.

Referring to the charged molecule at pH 7, the substance is not expected to adsorb to the solid soil phase.