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

Endpoint summary

Additional information

This titanate is hydrolytically unstable with half-life less than 10 minutes at 25 deg. C. The progress of the hydrolysis was followed by monitoring 2 -methylpropanol and ethyl acetoacetate, the main degradation products of the substance (Brekelmans 2013). The third non-hazardous degradation product (hydrated titanium oxide) is insoluble, lacking bioavailability in aquatic environment, and therefore not further considered in CSA.

Because of the rapid hydrolysis of this substance, the intrinsic properties of aquatic toxicity are related to the main degradation products of this substance. This was also demonstrated in the aquatic toxicity key studies (daphnia and algae) conducted for this substance. Due to the rapid hydrolysis in aqueous test media, the degradation products (2 -methylpropanol, ethyl acetoacetate and hydrated titanium oxides) toxicity to the freshwater invertebrates and algae were investigated based on the measured 2 -methylpropanol and ethyl acetoacetate concentrations and the equivalent test item concentrations (Tobor-Kaplon 2013).

Based on the toxicity test results conducted for the substance, the short-term and long-term aquatic toxicity to other organisms (fish) was considered scientifically unjustified and the read-across data from the main degradation products were used as a key value in CSA.

Short-term toxicity to fish:

•The 96-h LC50 (mortality) to Leuciscus idus, 275 mg/L based on nominal concentrations (read-across from ethyl acetoacetate; European Chemicals Bureau 2002)

Short term toxicity to invertebrates:

•The 48-hour EC50 (immobilisation) to Daphnia magna, > 29 ethyl acetoacetate per litre and > 16 mg 2-methylpropanol per litre based on the measured TWA concentrations of the hydrolysis products at loading rate of 100 mg test item per litre (OECD 202; Tobor-Kaplon M.A. 2013).

•The 48-hour EC50 (immobilisation) to Daphnia magna, > 100 mg /l based on estimated test item concentrations (OECD 202; Tobor-Kaplon M.A. 2013).

Toxicity to algae:

•The 72h-EC50 (growth rate) to Pseudokirchnerella subcapitata, > 13 mg ethyl acetoacetate per litre and > 4 mg 2 -methylpropanol per litre; based on the measured TWA concentrations of the hydrolysis products at loading rate of 100 mg test tiem per litre (OECD 201; Tobor-Kaplon M.A. 2013).

•The 72h-EC50 (growth rate) to Pseudokirchnerella subcapitata, > 100 mg/l based on estimated test item concentrations (OECD 201; Tobor-Kaplon M.A. 2013).

•The 72h-NOEC (growth rate) to Pseudokirchnerella subcapitata, 13 mg ethyl acetoacetate per litre and 4 mg 2-methylpropanol per litre, based on the measured TWA concentrations of the hydrolysis product at loading rate of 100 mg test item per litre (OECD 201; Tobor-Kaplon M.A. 2013).

•The 72h-NOEC (growth rate) to Pseudokirchnerella subcapitata, 100 mg/l based on estimated test item concentrations (OECD 201; Tobor-Kaplon M.A. 2013).