Ethylenediamine-N,N'-di(acetic acid)

Endpoint summary

Description of key information

H2 ED2A has an infinite water solubility, an extreme low calculated octanol water partition coefficient, it is not expect to sorb to soil, sediment or sludge and has a very low bioaccumulation potential. ED2A is considered to be chemically stable. Biodegradation is therefore considered to be the only contributing removal mechanism.

Additional information

ED2A is mainly produced as intermediate for the production of chelates like EDTA.

There is only limited information available on ED2A mainly generated to support the read across from source chemical EDTA to target chemical ED2A. In the absence of actual measured data for H2 ED2A, the available data from H4 EDTA are read-across to fill the datagaps. All ecotox, fate and phys-chem data from H4 EDTA, Na2H2 EDTA, Na4 EDTA, HEDTA, H2 ED2A etc have been collated in a document which is compiled to justify the read across. This document is included in IUCLID 6, Chapter 13.

Each category member has an identical backbone structure which is substituted with carboxylic groups that result in a similar chemical reactivity. The available data indicate that all members of the category are likely to share comparable physicochemical and environmental properties.

Considering the absence of two acetates groups in H2 ED2A compared to H4 EDTA a similar or better biodegradation profile would be expected for H2 ED2A. A ready test with H2 ED2A did however not result in a ready result. Only after prolonging the study till 84 days and using river water as inoculum, > 60% biodegradation was observed by van Ginkel (2017). This result shows that ED2A is ultimately biodegradable. Pitter& Sykora (2001) were able to demonstrate inherent biodegradability of ED2A in a Zahn-Wellens test. The difference in results of these tests is most likely caused by the difference in sludge concentration used in these tests. These results show that ED2A is inherently and ultimately biodegradable. Therefore no further tests on terrestrial microorganisms are provided.

Considering the physico-chemical and fate properties of ED2A similar to EDTA an emission into the atmosphere is considered very unlikely. Photodegradation in air, is not considered to be an important fate process in the degradation process of ED2A in the environment. ED2A is like EDTA resistant to hydrolysis, neither strong acids nor alkalis will cause any degradation. Similar to EDTA, ED2A will not significantly accumulate in organisms and due to the ionic structure and extreme hydrophilicity under environmental relevant pH conditions, no adsorption onto the organic fraction of soil or sediments is expected (EU Risk assessment, 2004).