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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 accordance with column 2 of REACH Annex VIII, the study does not need to be conducted if based on the physicochemical properties the substance can be expected to have a low potential for adsorption (e.g. the substance has a low octanol water partition coefficient), or the substance and its relevant degradation products decompose rapidly. 2-aminoethyldiisopropylamine (CAS 121 -05 -1) has a log Kow of 1.07 (BASF, 1993; @pH 10.6, uncharged molecule).

 

Estimates by the MCI method and the log Kow method of KOCWIN v2.00 (EPISuite v4.11; BASF SE 2016) calculated for 2-aminoethyldiisopropylamine log Koc values of 2.14 (MCI) and 1.43 (log Kow).

 

However, the pKa of 9.96 (calculated, BASF SE, SPARC v4.6, 12th June 2015) indicates that the substance will primarily exist as a cation in the environment. Cations generally adsorb stronger to soils containing organic carbon and clay than their neutral counterparts. Franco & Trapp (2008, 2009, 2010) have developed a method to take this effect into consideration when assessing the adsorption potential. The model is not yet validated; in addition, the applicability domain is not clearly defined. Nevertheless, the Koc values of the Franco & Trapp method give a good indication on the adsorption potential of a substance depending on the pH conditions of soil. The method is based on the dissociation constant pKa and the log Kow for the uncharged molecule. The pKa of 2-aminoethyldiisopropylamine is 9.96. For the log Kow of the uncharged molecule, the calculated value of 1.07 (BASF, report no. 93P11293, 1993; @pH 10.6, uncharged molecule) was used.

Regarding the charged molecule, at pH 7 the log Koc was estimated to be 2.5 (Koc = 319 L/kg) following the method of Franco & Trapp (2008, 2009, 2010). The correction was performed for pH 5, 7, and 8, which represents 98% of the European soils. The value at pH 7 will be used as key value, i.e. for PEC and PNEC calculations.

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

 

 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 2-aminoethyldiisopropylamine (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.