Reaction mass of Disodium decyl(sulphonatophenoxy)benzenesulphonate and Disodium oxybis[decylbenzenesulphonate]

Endpoint summary

Additional information

The available aquatic toxicity data from testing with DOWFAX 3B2 were all short-term studies in three species of freshwater fishes and aquatic invertebrates (D. magna). The key parameters for acute toxicity tests with fish and daphnids were 3.7 - 5.0 mg/L (range of 96 -hour LC50 values for fathead minnow, bluegill, and rainbow trout), and 1.5 mg/L (48 -hour EC50 value for D. magna).

Studies with the freshwater algae P. subcapitata were available from testing with category members DOWFAX 2A1 and DOWFAX 8390. For DOWFAX 2A1, a 96 -hour EC50 of 840 mg/L was reported based on cell counts, with a corresponding NOEC of 298 mg/L. In the case of DOWFAX 8390, the 72 -hour EC50 and NOEC values were > 100 mg/L and 10 mg/L, respectively, based on growth rate inhibition.

In addition, long-term aquatic toxicity data for DOWFAX 2A1 and DOWFAX 8390 were available from testing with the freshwater invertebrates. For DOWFAX 2A1 (tested as the equivalent DOWFAX 2EP), the 168 -hour NOEC values for mortality and reproduction of C. dubia were 0.65 mg/L and 1.08 mg/L, respectively. In the case of DOWFAX 8390, the reported 21 -day NOEC values with D. magna were 0.7 mg/L for both mortality and reproduction.

Of these aquatic toxicity values, the NOEC value of 0.65 mg/L for long-term toxicity of DOWFAX 2A1 to the invertebrate C. dubia was the lowest value reported, and this data point was used in the development of PNEC_aquafor DOWFAX 3B2.

There were activated sludge respiration inhibition studies for analogous structures to DOWFAX 3B2. From these studies, the EC50 value for DOWFAX 8390 in the activated sludge respiration inhibition test was reported as >284 mg/L, and this value was used to set the PNEC_STPvalue for DOWFAX 3B2.