Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Additional information

Reliable results are available from short-term tests with fish, aquatic invertebrates and algae. LL50/EL50 values determined in tests conducted with water-accommodated fractions (WAFs) of CTO were 20, 32 and >100 mg/L for Danio rerio (fish), Daphnia magna (invertebrate) and Desmodesmus subspicatus (algae). A NOELR of ≥100 mg/L was also determined in the test with D. subspicatus. These results represent the lowest values obtained in five or six equally reliable tests carried out on different samples of CTO.

No measured data are available for long-term toxicity of CTO to fish. A data-waiver is considered to be appropriate for this endpoint on the following grounds:

- The results from the short-term tests indicate that fish and invertebrates are similarly susceptible to the substance and algae are less susceptible. Reliable long-term test data are available for invertebrates (see section 6.1.4) showing an absence of toxicity at a loading rate of 1 mg/L.

- Calculation of PNECs for the aquatic compartment will be based on data for the blocks of constituents rather than on data for the whole substance.

Testing for long-term toxicity to fish will therefore not contribute to the database that is required to complete the assessment of the substance

A reliable 21 day NOELR of ≥1 mg/L has been determined for the effects of the test substance on reproduction, growth and mortality of Daphnia magna. The result was obtained in a test conducted on the sample of CTO that showed the highest toxicity in the short-term test with D. magna.