Bis(ethyl acetoacetato-O1',O3)bis(2-methylpropan-1-olato)titanium

Toxicity to aquatic algae and cyanobacteria

Description of key information

The 72-hour EC50 (growth rate) to Pseudokirchneriella subcapitata, > 100 mg/l based on estimated test item concentrations as per OECD 201 in accordance with GLP. The test item concentration corresponds to the measured concentrations of 13 mg/l ethyl acetoacetate and 4 mg/l 2-methylpropanol in test solutions.

Key value for chemical safety assessment

EC50 for freshwater algae:

100 mg/L

EC10 or NOEC for freshwater algae:

100 mg/L

Additional information

The key study on acute toxicity test performed for this substance identifies that toxicity of this substance is related to the degradation products due to the rapid hydrolysis which takes place immediately after test substance is introduced to water solution. The test substance is highly hydrolytically unstable and the quantitative analysis of the test substance was not possible. Therefore, the samples were analysed on the hydrolysis product of the test substance, ethyl acetoacetate and 2 -methylpropanol. The results were expressed based on the measured concentrations of ethyl acetoacetate and 2 -methylpropanol and the equivalent test item concentrations.

Under the conditions of the OECD 201 study conducted in accordance with GLP, the EC50 for growth rate reduction (72h-ERC50) and the EC50 for yield inhibition (72h-EYC50) was beyond the range tested, i.e. exceeded TWA concentration of 13 mg ethyl acetoacetate and 4 mg 2-methylpropanol per litre. These concentrations were obtained in an undiluted filtrate prepared at a loading rate of 100 mg test item per litre. The 72h-NOEC for growth rate reduction was based on TWA concentrations, 13 mg ethyl acetoacetate and 4 mg 2-methylpropanol per litre. These concentrations were obtained in an undiluted filtrate prepared at a loading rate of 100 mg per litre.

The most reliable supporting study on 2 -methylpropanol reports the 48-h EC50 (growth rate) of 2300 mg/l to Desmodesmus subspicatus ( Kuhn & Pattard 1990). The 72-h EC50 (growth rate) of ethyl acetoacetate to Desmodesmus subspicatus is > 500 mg/l based on nominal test concentrations (European Chemicals Bureau 2002).

Results of the key study do not lead to the classification of the substance as toxic to aquatic organisms in accordance with the criteria set out in Directive 67/548/EC and Regulation (EC) 1272/2008. The key study is classified as reliable without restrictions and satisfies the guideline requirements for the algae toxicity study.