Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

The substances MAPTA-ABS salt and MAPDA-ABS salt are surface-active substances. They consist of an amine part, either a tertiary amine (MAPDA-ABS) or a permanently cationic quaternary amine (MAPTA-ABS), and a sulfonic acid. The pKa for the tertiary amine is 9.18, which means that it will be cationic at environmental pH. The sulfonic acid part has a pKa of below 1

Under environmental conditions the substances will be ionised and will have a very low vapour pressure. The solubility in water has been determined to 300 mg/L. Evaporation from water is expected to be low is based on the low vapour pressure and the water solubility. The actual dissolved concentration in water will be low as the substances of this category will adsorb strongly to surfaces both based on hydrophobicity and ionic interaction where the ionic interaction will govern the partitioning process.

The distribution of the substances can be predicted assuming infinite time for equilibration using a Mackay level 1 model (MW = 399 g/mol; VP = 0.00084 mPa; S = 300 mg/L and Log Kow = 0.19 to predict sorption). According to the model close to 100 % (99.9 %) is predicted to end up in water. The remaining fraction is predicted to be found in sediment 0.1%.