Acute toxicity of a didecyldimethylammonium chloride‐based wood preservative, bardac 2280, to aquatic species

Abstract

AbstractThe acute toxicity of the antisapstain wood preservative Bardac 2280 (principal active ingredient 80% didecyldimethylammonium chloride, DDAC) was tested with four fish and four aquatic invertebrate species. White sturgeon fry (Acipenser transmontanus) were the most sensitive fish species tested with a 24‐h 50% lethal concentration (LC50) value between 1 and 10 ppb Bardac 2280. The 96‐h LC50 values for the three other fish species ranged from 0.39 ppm for fathead minnows (Pimephales promelas) to 2.0 ppm for juvenile starry flounder (Platichthys stellatus). Developmental stage altered the sensitivity of coho salmon to Bardac 2280, with alevins being approximately twice as sensitive as smolts. Altering salinity up to 30‰ seawater had no significant effect on the toxicity of Bardac 2280 to coho smolts. The 48‐h LC50 values for Daphnia magna, Mysidopsis bahia, Hyalella azteca, and Neomysis mercedis were 0.037 ppm, 0.039 ppm, 0.106 ppm, and 0.947 ppm, respectively. Bardac 2280 characteristically produced steep concentration–response curves for fish, i.e., a concentration range considerably less than 10‐fold for a complete range of mortality, and caused no major symptoms of sublethal stress in juvenile starry flounder following a 24‐h exposure.