Carbon disulphide

Long-term toxicity to aquatic invertebrates

Description of key information

A long term invertebrate study is scientifically not justified for several reasons: 1) the half life of CS2 in water is in the order of hours and it is not feasible to maintain a constant concentration for several weeks in long term test. 2) the anthropogenic concentrations in surface water in the immediate vicinity of plants where CS2 is emitted are far below the PNEC (see section 5 of this file) 3) biogenic emissions can lead to concentrations up to 11 mg/L during summer (Venice lagoon, see section 5), so well above the acute LC50 values. Still the Venice lagoon contains several species of fish 4) the difference between the acute LC50 for fish and the 8-day NOEC for fish is a factor of three, which is in line with the readily biodegradability of CS2 in most organuisms.

Additional information

A long term invertebrate study is technically not feasible, the half life of CS₂ in water is in the order of hours and it is not feasible to maintain a constant concentration for several weeks in long term test. In addition the anthropogenic concentrations in the environment in the immediate vicinity of plants where CS₂ is emitted are far below the PNEC (see section 5 of this file); the estimated PNEC is 10 µg/L and the highest ever concentration that was measured in Canada near a plant that is now shut down was 25 µg/L. Typical concentrations are in the range of 1 µg/L. Furthermore biogenic emissions can lead to concentrations up to 11 mg/L during summer (Swiss lake, see section 5), so well above the acute LC₅₀ values. Still the lake contains several species of fish. The difference between the acute LC₅₀ for fisch and the 8-day NOEC for fish is limited; a factor of three (which is in line with the ready biodegradability of CS₂ in most organisms). For these reasons we feel that the long term aquatic invertebrate test is scienticifally unjustified.