Reaction products of ethylene glycol, urea and paraformaldehyde (EUF)

Toxicity to aquatic algae and cyanobacteria

Description of key information

EUF was also tested for inhibition of algal growth with the species Desmodesmus subspicatus according to OECD 201. Analytical monitoring showed a decrease of the total formaldehyde concentrations during the test period. Therefore, the effect values were calculated based on the arithmetic mean between the measured t0 and t72h concentrations. Based on biomass production and growth rate, EC50s of 9.4 mg/L and 13.0 mg/L were calculated. The EC0 based on the growth rate was determined to be 4.5 mg/L.

Additionally the inhibition of algal growth on the marine species Skeletonema costatum was investigated according to ISO 10253 resulting in a nominal EC50 of 3.56 mg/L and a NOEC of 1.78 mg/L after 72 h. The test substance concentration was not monitored during the test. Assuming a similar decrease like during the freshwater test (to 38% of nominal after 72 h), the effective concentrations (geometric mean) were calculated to 2.19 mg/L (EC50) and 1.10 mg/L (NOEC).

Key value for chemical safety assessment

EC50 for freshwater algae:

13 mg/L

EC50 for marine water algae:

2.19 mg/L

EC10 or NOEC for freshwater algae:

4.5 mg/L

EC10 or NOEC for marine water algae:

1.1 mg/L