Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

If 2 -(2 -(2 -butoxyethoxy)ethoxy)ethanol, a representative molecule for this substance, is present in ambient air, it is expected to exist almost entirely in the vapour phase. This substance is not expected to absorb UV light in the environmentally significant range of >290 nm and is not therefore expected to undergo direct photolysis on sunlit soil surfaces, in the atmosphere or in aquatic environments. However, modelling predicts that it is likely to undergo indirect photolysis through hydroxyl radical reaction at a fast rate, with an estimated half life of 2.5 hours (0.21 days) at an OH concentration of 1.5million OH/cm3 and a 12 hour day). Based on its chemical structure, the substance is expected to be hydrolytically stable under normal environmental conditions. It should be borne in mind that the vapour pressure is so low that transport to the atmospheric compartment is not an important fate mechanism.

In a guideline (OECD 301D) and GLP ready biodegradability study, a substance corresponding to the description "Ethanol, 2-butoxy- ,manufacture of, by-products from" gave a positive result (>60% degradation relative to the COD value) with a maximum of 76% biodegradation recorded on day 28. In a similar GLP and guideline study a similar substance described as "Poly(oxy-1,2-ethanediyl), α-butyl-ω-hydroxy" attained 69% degradation after 28 days. Both of these similar substances can can therefore be considered as ready biodegradable under the strict terms and conditions of this guideline. In a screening marine biodegradability study, a glycol ether meeting the description "Poly(oxy-1,2,-ethanediyl), α-butyl, ω-hydroxyl" gave a positive result (>68 % degradation relative to the COD value) after 28 days. In a guideline (OECD 306) and GLP biodegradability study in seawater, the same glycol ether gave a positive result (>60% degradation relative to the COD value) with a maximum of 70% recorded on day 28. It may therefore be concluded that these substance are readilyy biodegradable in both freshwater and seawater. Biodegradation testing in soil is not required as the substance is readily biodegradable.