Registration Dossier

Diss Factsheets

Environmental fate & pathways

Bioaccumulation: aquatic / sediment

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

The direct and indirect exposure of the aquatic compartment is unlikely because HDI Uretdion hydrolyses completely in water within less than 12 hours. Therefore calculated BCF-values were reported for 1,3-Diazetidine-2,4-dione, 1,3-bis(6-isocyanatohexyl) (CAS No. 23501-81-7), the main constituent of HDI Uretdion (n=2), . A bioconcentration factor (BCF) of 457 and 143 L/kg wet-wt for the main constituent of HDI Uretdion (n = 2) and its corresponding diamine were obtained (Currenta, 2014 e/Currenta, 2014 f). It should be noted that the corresponding diamine was not found in any of the studies and is only of theoretical interest.

Key value for chemical safety assessment

BCF (aquatic species):
457 L/kg ww

Additional information

The direct and indirect exposure of the aquatic compartment is unlikely because HDI Uretdion hydrolysis rapidly in water within far less than 12 hours at environmental relevant concentrations. For this reason, an experimental study is not useful, and calculated values were used. The hydrolysis product is a complex mixture of water-insoluble oligomeric and polymeric ureas and of 1,3-Diazetidine-2,4-dione, 1,3-bis(6-isocyanatohexyl), the main component of HDI Uretdion, where the isocyanate groups have been transformed to amino groups. Although being a more theoretical approach, an ideal structure the “corresponding diamine of HDI Uretdion (n=2)" was considered in order to get an estimation on the bioaccumulation behaviour of the hydrolysed product.