I.L. 6-Acute toxicity of RDX to bluegill (Lepomis macrochirus) under varying conditions of water quality during static toxicity tests. 7-Acute toxicity of aged solutions of RDX to bluegill (Lepomis macrochirus) during static toxicity tests. 8-Acute toxicity of RDX to aquatic invertebrates and fishes during dynamic toxicity tests (nominal concentration). 9-Mean measured 14C-residues calculated as RDX, in water during 28 days continuous exposure of bluegill (Lepomis macrochirus), channel catfish (Ictalurus punctatus) and fathead minnow (Pimephales promeals) to nominal concentrations of 0.010 and 1.0 mg/i 14C-RDX. 0 20 C)a water quality criterion of 0.35 mg/i RDX is proposed for the protection of freshwater aquatic life with an adequate margin of safety. vii 4 Test Organisms Algae tested were the cyanophytes (blue-greens) Microcystis aeruginosa and Anabeana flos-aguae; the chlorophyte (green) Selenastrum capricornutum; and the chrysophyte (diatom) Navicula pelliculosa. Cultures were obtained from the collection at the

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A new method is described for determining mortality of bioassay organisms attributable to acidic and nonacidic constituents of an acid waste and for using these measurements to derive a limiting permissible concentration for the whole waste at boundaries of an oceanic mixing zone. The method reports mortality attributable to the acidic constituent in terms of its direct cause-hydrogen-ion concentration (|H+|) of bioassay water. Titration of acid waste into a representative sample of seawater from the mixing zone is then performed to obtain a limiting permissible concentration for the whole waste that recognizes the dominant role of neutralization in reducing concentration and toxicity of the acidic constituent in the zone. The method, which is demonstrated for a byproduct hydrochloric acid with the copepod Acartia tonsa as the bioassay organism, can be modified for use with alkaline wastes.

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Acute toxicity tests were conducted with selenium and five estuarine organIsms , and chronic or early life stage tests were conducted with mysld shrimp (Mysldopsls bah/a) and sheepshead minnows (Cyprlnodon varlagatus). The concentrations of selenium lethal to 50% ot the test animals after 96 hours of exposure (96-hour LCSO's) ranged from 1.2 mg/1 for brown shrimp (Penaeus aztacus) to 7.4 mg/1 for sheepshead mlnnbws. The maximum acceptable toxicant concentration (MATC) was > 0.14 < 0.32 mg/1 for mysld shrimp and > 0.47 < 0.97 mg/1 for sheepshead minnows. The application factor limits for mysld shrimp and sheepshead minnows were 0.09-0.21 and 0.06-0.13, respectively.