Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Additional information

A limited number of acute toxicity studies are available in fish. These clearly show that the substance 2-(2-(2-ethoxyyethoxy) ethoxy)ethanol is practically non-toxic to fish. The LD50 was always in excess of the maximum tested dose. The substance and its main metabolite have been tested in the zebrafish embryotoxicity study and neither showed any evidence of toxicity up to the maximum tested dose of 10mM (1780mg/L for 2 -(2 -(2 -ethoxyethoxy)ethoxy ethanol.

The position is similar in invertebrates. A limited number of studies again clearly show that the substance 2-(2-(2-ethoxyyethoxy)ethoxy)ethanol is practically non-toxic to daphnia and artemia. The LD50 was always in excess of the maximum tested dose.

There is no measured value available for the toxicity to algae for this substance. There is however measured data for two substances either side of it in the homologous series of these triethylene glycol ethers. A full and detailed justification for a category approach for meeting the individual data requirements for glycol ethers is included as an attachment in chapter 13 to this dossier. For this specific end point, this approach shows a clear trend of decreasing toxicity to aquatic species with reducing length of the alkyl chain length of the alcohol used to produce the glycol ether. Interpolation from the results of other glycol ethers within the same homologous family of triethylene glycol ethers can be considered a valid approach to meeting the data requirements of this substance. 2-(2-(2 -methoxyyethoxy)ethoxy)ethanol (TEGME) has a measured 72hr EC0 of >500mg/l (maximum tested dose) whereas 2-(2-(2 -butoxyyethoxy)ethoxy) ethanol has a measured 72 hr EC10 of 613mg/l.. The value for 2-(2-(2-ethoxyyethoxy) ethoxy)ethanol (TEGEE) will fall somewhere in between. These values are consistent with those predicted by the QSAR ECOSAR, with the model being somewhat more conservative. On this basis, the value chosen for the EC50 and NOEC/EC10 values are those predicted by the QSAR, which also happen to be similar to the lowest of the values from the surrogate substances.

Studies are available on sewage sludge micro-organisms and a broad spectrum micro-organism mixture. Both studies showed that the substance is practically non-toxic to micro-organisms.