Registration Dossier

Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

The test substance is with high probability not acutely harmful to aquatic algae. No toxic effects occur within the range of solubility.

Key value for chemical safety assessment

Additional information

A GLP guideline study using Pseudokirchneriella subcapitata and according to OECD 201 is available (BASF SE 2015). Due to the low solubility of the test item saturated solutions (differential loading) have been prepared. However, analyses of the test substance preparations were not conducted, since a reliable method for analyses in the required concentration range could not be developed. After 72 h of exposure no inhibitory effect on algal yield or growth rate have been observed. Therefore, the EC10 and the EC50 were determined to be > 100 mg/L (loading rate).

Additionally, in an algae toxicity study according to guideline AFNOR T90-304, Scenedesmus subspicatus (~6.0E+05 cells/mL) were exposed to nominal test substance concentrations of 0 (control), 17, 22, 29, 48, 62 and 100 mg/L under static conditions for 5 days. Inhibition of growth was first seen at the concentration of 29 mg/L and increased constantly to a total inhibition of 42.4% at the highest concentration tested. As growth inhibition did not exceed 50%, the 120-h EC50-value is >100 mg/L. However, according to ECHA guidance R. 7b algae tests with a duration of >96 h cannot be used, since it cannot be assumed that the algae are in the exponential growth phase during the whole exposure period, unless the available raw data show monotone exponential growth of the controls. Since these data are not available the study is disregarded.