The acute and chronic toxicity of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) to three freshwater invertebrates

Abstract

Abstract The acute and chronic toxicities of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) to adaphnid (Ceriodaphnia dubia), a hydra (Hydra littoralis), and a midge (Paratanytarsus parthenogeneticus) were examined. RDX concentrations at the solubility limit of the compound under specific test conditions (17.0 mg RDX/L, Ceriodaphnia dubia at 25°C; 32.3 mg RDX/L, Hydra littoralis at 22°C; and 29.2 mg RDX/L, Paratanytarsus parthenogeneticus at 22°C) were not acutely toxic to any of the three tested invertebrates. In a 7-d survival and reproduction test with Ceriodaphnia dubia, RDX caused no significant effect on survival, but reduced reproductive success. The no-observed-effect concentration, lowest-observed-effect concentration, and chronic value for Ceriodaphnia dubia were 3.64, 6.01, and 4.68 mg/L, respectively. In an egg-to-egg life cycle test with Paratanytarsus parthenogeneticus, survival, growth, egg production, and hatching success were unaffected by RDX. Although not statistically significant, reductions in emergence success were observed at concentrations as low as 6.78 mg/L.