Registration Dossier

Environmental fate & pathways

Biodegradation in soil

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

Biodegradation in soil was examined for cetrimonium chloride. For these types of substances, the degradability is determined by the alkyl structure and not the counter-ion. Therefore the degradability of cetrimonium chloride represents that of cetrimonium bromide. The biodegradability was measured followed by the 14CO2 evolution from 14C-labelled substances added to the soil. The biodegradation in soil of cetrimonium chloride was approximately 60% in 58 days.

Key value for chemical safety assessment

Half-life in soil:
58 d
at the temperature of:
22 °C

Additional information

Biodegradation in soil was examined for cetrimonium chloride. For these types of substances, the degradability is determined by the alkyl structure and not by the counter-ion. Therefore the degradability of cetrimonium chloride represents that of cetrimonium bromide. The biodegradability was measured followed by the 14CO2 evolution from 14C-labelled substances added to the soil. The biodegradation in soil of cetrimonium chloride was approximately 60% in 58 days. Based on the results, cetrimonium chloride can be considered as biodegradable in soil and not persistent. The same can be concluded for cetrimonium bromide, as the biodegradability is not determined by the counterion. It can be concluded that the half-life in soil for cetrimonium bromide is less than 58 days.

The biodegradability of cetrimonium bromide in soil was confirmed in a published study testing the biodegradation by soil microorganisms using a standard BOD technique. The aqueous test system uses an aqueous suspension of silt loam as inoculum. The study showed that soil microorganisms in suspension are able to degrade cetrimonium bromide at concentrations up to 25 µg/ml test solution. However, the biodegradation seems to be completely inhibited at 100 µg/ml, which is probably due to the toxicity of cetrimonium bromide to the microorganisms.