Barium sulphide

Short-term toxicity to aquatic invertebrates

Description of key information

Reliable acute toxicity data for invertebrates are available for sulfide, sulfate and barium. Barium and sulfide are released upon dissolution of BaS in the aqueous environment. Sulfide is rapidly oxidised under natural environmental conditions. Thus, only acute but not long-term effects due to sulfide exposure are expected. Further, the acute toxicity of sulfate was considered. However, sulfate is of low toxicity.
A reliable 96h-LC50of 0.020 mg H2S/L for the larvae of the mayfly Beatis vagans has been reported by Oseid and Smith (1974) corresponding to the 96h-LC50of 99.4 µg BaS/L.
For the marine environment, the lowest reliable acute value was 0.032 mg H2S/L for the penaid prawn Penaeus indicus (Gopakumar and Kuttyamma, 1996) corresponding to the 96h-LC50of 0.159 mg BaS/L.
A reliable, nominal 48h-EC50of 14.5 mg Ba/L forDaphnia magnais reported by Biesinger and Christensen (1972) resulting ´by read-across ín the 48h-EC50of 17.9 mg BaS/L.
Comparing acute toxicity levels of Ba and S in freshwater, it can be concluded that the acute toxicity of BaS to invertebrates is driven by sulfide resulting in the 96h-LC50 of 0.099 mg BaS/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

99.4 µg/L

Marine water invertebrates

Marine water invertebrates

Effect concentration:

159 µg/L

Additional information

Biesinger and Christensen (1972) reported a nominal 48h-EC₅₀of 14.5 mg Ba/L for the water fleaDaphnia magna(total Ba concentrations).

The lowest reliable acute toxicity endpoint for freshwater invertebrates with regard to sulfide was reported by Oseid and Smith (1974) for the larvae of the mayflyBeatis vagans, i.e., the 96h-LC₅₀of 0.02 mg H₂S/L corresponding to 0.099 mg BaS/L. Gopakumar and Kuttyamma (1996) reported the lowest reliable acute toxicity endpoint in the marine environment for the penaeid prawnPenaeus indicus, i.e., the96h-LC₅₀of 0.032 mg H₂S/L corresponding to 0.159 mg BaS/L.

In oxic environments, however, sulfide released from BaS is oxidized to sulfate, and the hazard of the released sulfur should be evaluated by reading-across the toxicity of sulfate. The study by Mount et al (1997) was identified in the OECD SIDS for Na₂SO₄(i.e., the most relevant substance for assessing the hazard of sulfate) as key study with regard to acute toxicity of sulfate to invertebrates. This study reports a 48h-LC₅₀of 3080 mg Na₂SO₄/L for the water fleaCeriodaphnia dubiacorrespondingtoa 48h-LC₅₀of 3673 mg BaS/L.