ECOTOXICOLOGICAL RISK-EVALUATION OF THE CATIONIC FABRIC SOFTENER DTDMAC .1. ECOTOXICOLOGICAL EFFECTS

The acute and (semi-) chronic toxicity of ditallow dimethyl ammonium chloride (DTDMAC) to several aquatic organisms was determined in surface water. The acute toxicity (96-h LC50) for the stickleback Gasterosteus aculeatus, the midge larva Chironomus riparius and the pond snail Lymnaea stagnalis was 4.5, 9.2 and 18 mg/l respectively. The NOECs determined in (semi-) chronic toxicity experiments with the same species were 0.75, 1.3 and 0.32 mg/l respectively. The NOEC for the green alga Scenedesmus pannonicus, the bacterium Photobacterium phosphoreum (Microtox) and nitrifying bacteria was 0.75, 5.6 and 3 mg/l, respectively. From these results it can be concluded that DTDMAC is a rather toxic chemical and differences in species susceptibility to DTDMAC are small.