Effects of Surfactants on the Toxicity of Chemical Substances Acting on Daphnia (2^nd Report)
Toxicity When Chemical Substances and Surfactants Coexist

Abstract

EC₅₀ and LC₅₀ of Daphnia magna of acute toxicity tests for ten chemical substances (anesthetic) were determined. We also investigated the toxicity changes when the chemical substance coexists with a surfactant. The results of the binary acute toxicity tests using Daphnia magna on ten chemical substances and two surfactants, Polyoxyethylene (10) octylphenyl ether (POE) and Sodium dodecylbenzenesulfonate (DBS) were investigated using the toxic unit concept. In the case of POE-chemical system, 4 chemical substances exhibited simple additive. The other 6 chemical substances are considered to be slightly less than additive. In the case of DBS-chemical system, 7 out of 8 chemical substances tested were judged to be less than additive or antagonistic. DBS and Bisphenol A intake by Daphnia were analyzed. The decrease in the toxicity of Bisphenol A in the presence of DBS is concluded to be a decrease in the uptake of Bisphenol A in the bodies of Daphnia.