Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

For metals, the transport and distribution over the different environmental compartments e.g. the water (dissolved fraction, fraction bound to suspended matter), soil (fraction bound or complexed to the soil particles, fraction in the soil pore water,...) is described and quantified by the metal partition coefficients between these different fractions. The information on these partition coefficients is given under 5.6.

Partition coefficients for cadmium in freshwater have been reviewed in the EU risk assessment report (ECB 2008). Based on this experimental evidence, a partition coefficient for the distribution between solid particulate matter and water (Kpsusp) of 130 x 103 l/kg has been defined for EU waters and was used throughout the RAR..

The Kp for the distribution between sediment and water (Kpsed) was estimated in the RAR from the ratio of the average sediment (1.32mg/kgDW)to average water Cd concentrations (0.14µg/l). This "best fit" Kd yields 10000L/kgDW (ECB 2008).

These partition coefficients have been used since then in other legislative processes in the EU (e.g. the water framework directive) and will also be used for REACH.

For the marine water, a partition coefficient water/suspended matter of 617 l/kg has been derived.