On the toxicity and biodegradation of cationic surfactants

Three quaternary ammonium derivatives employed as cationic surfactants were subjected to standard laboratory bioassays to assess their relative toxicities to aquatic organisms. The tests were performed using Daphnia magna and the luminescent bacterium Photobacterium phosphoreum (Microtox assay) exposed to either dimethyldistearylammonium chloride (DSDMAC), cetyltrimethylammonium bromide (HTMAB) or cetylbenzyldimethylammonium chloride (HBDMAC). The results indicated that DSDMAC was less toxic than either of the other 2 surfactants, and that it underwent rapid biodegradation at concentrations of 2.5 and 10 mg per litre in water.