Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Additional information

The following effect data are available for the submission substance:

1) Short term toxicity test on Cyprinus carpio:

NOEC = 100 mg/L (nominal concentration)

LC50 > 100 mg/L (nominal concentration)

2) Acute toxicity test on Daphnia magna:

NOEC (48h): 32 mg/L (nominal concentration)

EC50 (48h): 32 -56 mg/L (nominal concentration)

3) Toxicity test on freshwater algae (Pseudokirchnerella subcapitata)

Growth rate reduction (72h):

NOEC = 3.2 mg/L (nominal concentration)

EC50 >100 mg/L (nominal concentraion)

4) Toxicity to microorganisms (activated sludge respiration inhibition)

EC50 (3h) >100 mg/L (nominal concentration)

In the studies on aquatic toxicity only a small fraction of the loading rate was dissolved. As shown by measured TOC values test substance concentrations increased with increasing loading rates and were stable throughout the test. From this it can be concluded that only a small fraction (the "more water soluble fraction") of this UVCB substance is solved in water and that its concentration in water is depending on the total amount of substance provided to the water phase. As it is reasonable to assume that this solved fraction is available to aquatic organisms and is responsible for the aquatic toxicity observed, the nominal concentrations (loading rates) are used to characterise the observed toxicity.

The most sensitve endpoint is therfore acute toxicity to Daphnia magna with an EC50 (48h) of 32 -56 mg/L (nominal). Some effects are seen on algal growth rate. On fish and microorganisms, no effects could be observed at the applied limit concentration of 100 mg/L nominal.