Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Adsorption:

Estimates by the MCI method and the log-Kow method of KOCWIN v2.00 (EPISuite v4.11; BASF SE 2015) calculated for 2-diethylaminoethanol log Koc values of 0.65 (MCI) and 0.57 (log Kow).

 

However, the measured pKa of 10.1 (Brisset et al., 1971) 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 moelcule. The pKa of2-diethylaminoethanolis 10.1 (measured; Brisset et al., 1971). For the log Kow of the uncharged molecule, the measured value of 0.21 (BASF AG, 1987) was used.

Regarding the charged molecule, at pH 7 the log Koc was estimated to be 1.86 (Koc = 72 L/kg) following the method of Franco & Trapp (2008, 2009, 2010), based on these data. 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.

Moreover, the chemical is readily biodegradable.

 

Henry’s Law Constant (HLC):

The Henry’s Law Constant was calculated by using the bond estimation method of HENRYWIN v3.20 (EPISuite v 4.11) to be 3.17E-04 Pa*m³/mol. The estimation refers to the uncharged molecule. The substance is within the applicability domain of the model. Based on the calculated data the substance is not expected to evaporate into the atmosphere from the water surface.

 

Distribution Modelling:

Based on the results of the Mackay LEVEL I v3.00 calculation, the substance will preferentially distribute into the compartment water (99.2%) and air (0.8%); the data refer to the uncharged molecule (pKa value: 10.1).However, since the substance will be ionized under environmentally relevant conditions, the distribution into water may still be underestimated.