Acute Toxicity of Smoke Screen Materials to Aquatic Organisms, White Phosphorus-Felt, Red Phosphorus-Butyl Rubber and SGF (Smoke Generator Fuel) No. 2 Fog Oil

摘要

The acute toxicity of three obscurants was determined for nine fresh-water organisms. The materials tested were white phosphorus-felt smoke, red phosphorus-butyl rubber (RP-BR) smoke, and smoke generator fuel (SGF) No. 2 fog oil (bulk and vaporized). The chemistry of WP-F and RP-BR smoke in water and the resulting effects on aquatic organisms were similar. Combustion of these two obscurants and their deposition in water leads to the formation of many complex oxy-phosphoric acids. Rates of hydrolysis of these complex products to ortho-phosphate were inconsistent and unpredictable over time. These products acidify water and produce toxic effects after exhausting the buffering capacity of the water. The 96-hr median lethal concentration (LC50) values for fish ranged from 3.9 to 5.1 pH units. The values for invertebrates ranged from 3.4 to 5.5. Algal growth was inhibited at pH levels less than 6.0. Acute 96 hr tests using Daphnia magna with neutralized and nonneutralized exposure solutions indicated that the presence of unidentified toxic component(s) acted independently of pH. Additions of phosphorus into aquatic systems can lead to stimulation of algal growth as long as the resulting pH is not toxic. Neither the bulk fog oil nor the vaporized fog oil was acutely toxic to freshwater animals at concentrations less than 10 mg/l total oil. Concentrations of bulk fog oil in excess of 2.4 mg/l total oil significantly inhibited algal growth in two of the three batches tested. Photolysis increased the concentration of water-soluble components of the fog oil. The three obscurants tested have the potential for adverse environmental effects.