Bottom residues resulting from the synthesis of propene by propane dehydrogenation

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Justification for type of information:

The substance is a hydrocarbon UVCB. As the biodegradation properties of some main components are known a biodegradation screening test is not considered to be appropriate.
The main component benzene, CAS 71-43-2 (35-70%) is considered as readily biodegradable: As reported in the registration dossier of benzene: "Data is available from standard ready biodegradation screening studies to demonstrate that benzene is readily biodegradable. Shell (2000) and Brixham Environmental Laboratory (2001) both report results from OECD 301F tests which showed that benzene met the criteria to be classed as readily biodegradable. This was also the conclusion reached in the EU RAR for benzene (2008)."
However, one of the other main components, methylcyclohexane, CAS108-87-2 (5-20%), is considered to be poorly biodegradable as cited in the OECD SIDS Oct 2014: "A readily biodegradation test on methylcyclohexane was conducted with activated sludge based on OECD TG 301D. The concentration of methylcyclohexane was 10 mg/L, and 1 drop of the activated sludge from the waste-water treatment plant was put into the 1 L test solution with the cultivation period of four weeks. The test result showed 0 % degradation by BOD. Therefore, methylcyclohexane is not readily bio-degradable."
In respect to this results a biodegradation screening test is scientifically not necessary.