Registration Dossier

Ecotoxicological information

Toxicity to soil microorganisms

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

Cetrimonium bromide is toxic to soil microorganisms. Depending on the soil type and microbial parameter measured, the obtained EC50 values for dehydrogenase activity and potential nitrification ranged from 2.0 to 7.4 g/kg, and the NOEC for potential nitrification was established to 21 mg/kg.

Key value for chemical safety assessment

Short-term EC50 for soil microorganisms:
2 000 mg/kg soil dw
Long-term EC10 or NOEC for soil microorganisms:
21 mg/kg soil dw

Additional information

Cetrimonium bromide is toxic to microorganisms. The toxicity seems to be related to soil types, and clay content seems to affect the toxicity, as addition of smectite clay will decrease the toxicity by increasing the adsorption of cetrimonium bromide to clay.

The identified EC50 values and NOEC are calculated for standard soils of 3.4 % organic matter. LOEC for nitrification was 41 mg/kg, however at highest level tested (2482 mg/kg), the inhibition was 16.3%, resulting in a very weak dose-response curve. NOEC is estimated as LOEC/2.