Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Additional information

According to REACH Annex VII and VII , acute studies do not need to be conducted "if there are mitigating factors indicating that aquatic toxicity in unlikely to occur, for instance if the substance is highly insoluble in water or the substance is unlikely to cross biological membranes". No such waiving guidance is available for the evaluation of chronic data. Sulphur dioxide, however, is a gaseous substance and does not remain present in the aquatic environment under this form: Sulfur dioxide will react with water (or water vapour) to form sulfurous acid (H2SO3). According to Eigen (1961), the reaction time for hydratation and reaching equilibrium is less than 1 second.

Consequently, an E(L)C50, EC10 or NOEC expressed as mg SO2/L cannot be determined (i.e., no acute or chronic reference values can be generated). Secondly, as SO2 is not present in the aquatic compartment for a relevant time period, this substance will not cross biological membranes, or will not interact with it in another way.