Subacute Toxicity of Wood Preservatives, DDAC and BAAC, in Several Aquatic Organisms

We investigated the subacute toxicity of 2 wood preservatives, DDAC (principal component: 37.5% didecyldimethyl ammonium chloride) and BAAC (principal components: 40% DDAC, 13.4% boric acid), in a number of aquatic invertebrates: a green alga (Selenastrum capricornutum), 2 cladocerans (Ceriodaphnia dubia and Daphnia magna), 2 fishes (Danio rerio and Oryzias latipes), and photobacteria (Microtox^<[○!R]>). DDAC and BAAC inhibited biological functions in all of the organisms tested; the order of sensitivity was green alga > cladocerans > fish. Growth of S. capricornutum was inhibited by both preservatives at very similar levels of exposure. DDAC inhibited reproduction in C. dubia at lower levels of exposure than for D. magna, and the reverse was true for BAAC. Both DDAC and BAAC reduced the survival rate of D. rerio at lower exposure levels than for O. latipes. However, phylogenetic class differences in sensitivity to the preservatives were much greater than species differences.