Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

The high water solubility and the low values of the Henry´s constant, soil sorption coefficient all indicate that DEGDN exists predominantly in the aqueous phase of the environment.

The environmental fate of DEGDN in surface water is dominated by photolysis with surface half-lives ranging from 15 days in summer to 59 days in winter at 40°N. The environmental quantum yield is 0.18. Photolysis of DEGDN initially forms nitrate ion and 2-hydroxyethyl nitroacetate; the latter photolyzes further to 1- and 2- carbon acids and additional nitrate.

DEGDN biotransforms with a second-order rate constant of 3.9 x 10-11mL.cell-1.h-1, corresponding to a half-life of about 2 years in a typical surface water (DEGDN half-lives can be projected from this average second-order rate constant and estimates of microbial populations). Intermediate biotransformation products were observed but were further transformed and did not accumulate.

The microbial biotransformation will be a major fate process for DEGDN when it is introduced into waters with other organic waste substrates. DEGDN is expected to move readily through soils because it had low soil sorption coefficients Kp of 2 and 0.8 g/mL on EPA-5 and EPA-18 sediments, respectively.