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

Hydrolysis

Description of key information

Hydrolytically unstable with the half-life time of < 10 minutes at 25 deg. C at pH 4, 7 and 9.

Key value for chemical safety assessment

Half-life for hydrolysis:

10 min

at the temperature of:

25 °C

Additional information

Study performed in accordance with GLP. However, as the substance is highly hydrolytically unstable it was not possible to perform the test as outlined in the guidelines. In order to obtain as much information on hydrolysis as possible, an alternative test was designed. The hydrolytic stability was tested in buffered aqueous solutions at pH 4.0, 7.0 and 9.0 at 25 ⁰C for 40 minutes. The progress of hydrolysis was followed by monitoring ethyl acetoacetate and 2 -methylpropanol, the hydrolysis products of the substance. Based on the results, it was concluded that the hydrolysis half -life time for the substance was <10 minutes. Additionally, the formation of a white precipitation was observed during the hydrolysis study. This is most likely due to the formation of the insoluble titanium oxides.

Based on the Tier 3 approach, no other degradation products were identified at quantitative level. The response of the hydrolysis products ethyl acetoacetate and 2-methylpropanol was > 69% (area). In the chromatograms, small additional peaks with an area In the chromatograms, small additional peaks with an area < 1% were observed at 4.69 minutes, 5.31 minutes (at pH 7 and pH 9), 6.02 minutes and 6.97 minutes (at pH 4). Two additional peaks with an area > 1% were observed at the retention time of 2.92 and 3.26 minutes.

To achieve sufficient sensitivity for the analysis of the identified hydrolysis product, selected ion monitoring was used as detection method. Therefore it was not possible to obtain accurate information on the mass fraction of the unknown peaks nor to record their entire mass spectrum, and hence it was not possible to identify these additional peaks. However, the patterns of the three m/z values showing response for the peaks at 2.92 and 3.26 minutes, i.e. m/z 31, 43 and 45, show similarity with the responses found for ethanol and isopropyl alcohol, respectively. All additional peaks might derive from impurities in the test substance and/or hydrolysis products.

The results of this study are considered reliable to be used for C&L purposes to conclude this substance to be hydrolytically unstable releasing only 2 -methylpropanol and ethyl acetoacetate and hydrated titanium dioxide when in contact with water. Based on the results this substance can be considered as rapidly degradable.