Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Primary fatty amine ethoxylates have pKa values close to 8.8 which is most likely almost independent of the alkyl chain length as observed for primary alkyl amines. This means that the largest fraction of the molecule is protonated under environmental conditions and will behave as salt in water. A vapour pressure of 0.00073 Pa was measured for the C12 -18 ethoxylated amine at 20 °C and which will be used as a worst-case for the primary fatty amine ethoxylates with a longer alkyl chain. The solubility of this cationic surface active substance will be influenced by the pH and is difficult to determine because of the surface active properties. As an alternative as suggested by the REACH guidance R.7 the CMC at pH 7 was determined.

For primary fatty amine ethoxylates CMC values ranging from 3.5 to 5.9 mg/L were measured. Evaporation from water is based on the low vapour pressure and the observed CMC values very unlikely. The actual dissolved concentration in water will be extremely low as ethoxylated amines will sorb strongly to sorbents both based on hydrophobicity and ionic interaction where the ionic interaction will govern the partitioning process. For silt soil a Kd of 4526 L/kg was observed indicating that once sorbed the substance has a low leaching potential.