Registration Dossier

Environmental fate & pathways

Adsorption / desorption

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

An estimation of an adsorption coefficient (Koc) on soil and on sewage sludge using HPLC is not possible to carry out because of the test substance characteristics (inorganic mixtures (UVCB)). 

Key value for chemical safety assessment

Additional information

In accordance with section 2 of REACH Annex XI, Regulation (EC) No. 1907/2006, the study does not need to be conducted as estimation of the adsorption coefficient (Koc) on soil and sewage sludge using HPLC is not possible to carry out because of the characteristics of oil shale thermal processing residue (inorganic UVCB substance with a multitude of variable constituents). Additionally the principle of the method is not suitable; HPLC on a reverse phase, which is not applicable for compounds of this character. A representable Kd calculation is therefore also not possible due to the multitude of unknown constituents that define the UVCB character of the test substance. Only a limited number of ranges for the trace elements can be calculated. Log Kd values of 2.76-4.2 are calculated for trace elements. Adsorption potential to soil is therefore possible. The oil shale thermal processing residue under consideration consists of oxides: SiO2, Al2O3, Fe2O3, CaO, MgO, K2O, Na2O, TiO2, P2O5, and other compounds in amount less than 1%. In general soils contain up to 95% SiO2 and other Oil Shale; Thermal Processing Waste components such as Al2O3 and Fe2O3 are also present most common in soils. Since SiO2 is a main element of oil shale, thermal processing waste, there is a natural relationship between the substance and soils in which it may even build up own its own soil horizons and can be used as a fertilizer.