Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Studies performed on 2,2,6,6-tetramethyl-4-oxo-piperidinooxy (4-Oxo Tempo) demonstrated the hydrolytic stability of the substance and the absence of ready biodegradability. In a guideline study (Fox, 2012), the half-life with respect to hydrolysis was extrapolated to be > 1 year at 25oC, a further guideline study (Commander, 2012) showed biodegradation of <2.6% over a 28 day period, significantly below the criteria laid out for ready biodegradability.

Biodegradation studies in additional aquatic compartments were not considered necessary as based on the exposure scenarios in the chemical safety report, direct or indirect exposure to the environment is unlikely.

The bioaccumulation or adsorption/desorption potential of the test substance was not defined by experimental data however based on the physical chemical properties of the substance (Log Kow 0.28 and water solubility 216 g/L) the substance is not expected to bioaccumulate or absorb. No further testing was considered necessary.