Registration Dossier

Diss Factsheets

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

The substance Octene, hydroformylation products, high boiling is considered to be ultimately biodegradable.

Additional information

BASF conducted an OECD TG 301 B study that showed a degradation of 80-90% after 28 days (BASF, 2008).  OECD TG 301 screening tests are designed to demonstrate readily biodegradability of substances (mono-constituents). Thus, the pass level and the 10-day window cannot be applied for multi-constituents nor UVCBs which are not of similar structures or homologues. However, the degradation rate of 80-90% TOC after 28 days shows that the substance is biodegradable to a high degree. Thus, an enhanced OECD TG 301 B was conducted in 2015 to determine whether the degradation rate would still increase to a complete degradation or a plateau level would be reached. The latter would give an indication that some constituents or fractions of the UVCB are possibly poorly or not biodegradable.


The result of an OECD TG 301 B (enhanced) study with a prolonged test duration demonstrated that Octene, hydroformylation products, high boiling is degraded completely (mean > 97-100%; 97%, 104%, 112%) after 42 days (BASF, 2015). The result clearly demonstrates that 100% of the measured TOC (according to ISO 9439) of the test substance was completely mineralized to carbon dioxide. The result of the inhibition control shows that the test substance is fully biodegradable and confirms the test assays results of 100% biodegradation and the reference assay result of 100% biodegradation.


This study demonstrates that with a high certainty, no poorly degradable or persistent constituents are present in the UVCB. Otherwise a plateau or stagnating degradation curve would be observed in the prolonged OECD TG 301 B study. Furthermore, the enhanced study confirms/replicates the results and degrading properties of the “regular OECD TG 301 B study from 2008 very well. This ultimate biodegradation of Octene, hydroformylation products, high boiling is demonstrating with higher confidence than any modelling that the substance and its constituents do not fulfil the PBT and vPvB criteria.