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Environmental fate & pathways


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Description of key information

The half-life of 28 d at 20 °C for tall oil diethylenetriamine imidazoline is read-across from the hydrolysis data from similar substance i.e. a TEPA based imidazoline. The read across of this realistic worst-case half-life is considered to be justified also taking the biodegradation data into account.

Key value for chemical safety assessment

Half-life for hydrolysis:
28 d
at the temperature of:
20 °C

Additional information

Imidazoline DETA

The imidazoline ring(s) of tall oil diethylenetriamine imidazoline most likely undergo(es) hydrolysis under alkaline, neutral and acidic conditions (Akzo Nobel 2010; Watts, 1990). A hydrolysis rate of an imidazoline has been measured using a Tetraethylene pentamine based imidazoline. For this imidazoline a number of hydrolysis rates were measured as the imidazolines are in general a mixture of imidazolines and amides (non ring closed imidazolines). The tetraethylene pentamine based imidazoline contains even di-imidazolines. The shortest half-lifes of 16.3 h at 20°C were found under neutral conditions for the hydrolysis of the first imidazoline ring of the di-imidazoline. For the next step in the hydrolysis degradation route i.e. the hydrolysis of the amide by which the alkyl chain is detached a half-life of 158 h at 20°C was derived. This second reaction step is considered to be representative of the hydrolysis of the DETA based imidazoline as this is also a monoimidazoline. The next step in hydrolysis degradation route would be the opening of the second imidazoline and here a half life of 28 days at 20 °C is derived. The order in which these last two hydrolysis reactions take place is not completely clear. When considering the biodegradation half-life of the DETA based imidazoline and the shape of the degradation curve it seems that a hydrolysis step is here a rate determining step. For read-across from the source chemical (TEPA based imidazoline) to the target chemical (DETA based imidazoline) the use of worst-case half-life of 28 days at 20°C is considered to be justified also taking the biodegradation half-life into account.