Registration Dossier

Environmental fate & pathways

Adsorption / desorption

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

The adsorption/desorption study was not conducted as (benzoato-O,O')hydroxy(octadecanoato-O,O')aluminium is expected to decompose rapidly to carbon dioxide, water and inorganic aluminium species. At environmental pH (ca 7.0), aluminium will mainly be in the form of insoluble hydrated oxide species which, although likely to absorb onto soil, are not expected to be an environmental risk as they are naturally abundant in the environment.

Key value for chemical safety assessment

Additional information

In accordance with column 2 of REACH Annex VIII, the adsorption/desorption study does not need to be conducted as (benzoato-O,O')hydroxy(octadecanoato-O,O')aluminium is expected to be readily biodegradable and the relevant degradation products decompose rapidly. The dissociation and biodegradation in the environment of the substances would result in carbon dioxide, water and hydrated aluminium oxide species.

No data for adsorption/desorption was included in the REACH dossiers for aluminium oxide or aluminium hydroxide. No data are available on the partition coefficient of purely inorganic aluminium compounds as, in accordance with column 2 of REACH Annex VII, the partition coefficient studies do not need to be conducted as the substances are inorganic. Aluminium is the most abundant metal to be found on earth making up 8.1% of the Earth’s crust (Lide, 2008). However, it is never found in the pure form but always in the form of minerals, for example bauxite, which is an impure form of hydrated oxide ore. As aluminium compounds are abundant in nature the adsorption/desorption of aluminium in the environment is not expected to be scientifically relevant.

In most cases the reactions to form the grease thickener occur in-situ during the grease manufacturing process and consequently grease thickeners normally only exist in the base oil matrix. In realistic use scenarios, the thickeners will be contained in base oil, with the formulated greases specifically designed to minimise the leaching of the thickener. As such, and given the very low solubility of the substance in water, the concentrations of the substance which would be available for adsorption to soil or sediment are limited.

References

Lide DR (editor) (2008) CRC Handbook of Chemistry and Physics (89th edition). CRC Press, Taylor and Francis Group