Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Additional information

Toxicity towards fish:

Acute toxicity to fish was determined in several species. Rainbow trout (Oncorhynchus mykiss) (Dionne, 1997) appeared to be the most sensitive fish species with regard to DAPD toxicity (in comparison to a.o. common carp (Cyprinus carpio) (Dionne, 1995)). The 96h-LC50 value for Rainbow trout was 0.48, while the NOECs (96h) was 0.14 mg/L. After long-term, 14 -days exposure, lowest toxicity values were still observed in Rainbow trout displayed by an EC50 of 0.26 mg/L and a NOEC of 0.14 mg/L after 14 days of exposure.

Toxicity towards invertebrates:

The short-term toxicity test performed with Daphnia magna provided an unbound EC50 value (immobility, 48h) > 1.8 mg/L, however a short-term NOEC of 0.36 mg/L was established (Putt, 1995). The long-term toxicity towards Daphnia magna was evaluated as well (Sacker, 2010). This resulted in an EC10(21 days; reproduction) of 0.0045 mg/L (estimated by extrapolation) and a Lowest Observed Effect Concentration (LOEC - reproduction) of 0.007 mg/L. An actual NOEC for reproductive effects could not be established. In the same test, the no observed effect value (NOEC) for parent Daphnia survival (21 days) was 0.016 mg/L, the EC10(survival, 21 days) was 0.027 mg/L. .

Toxicity towards freshwater algae:

Based on the growth rate, the EC50 (72h) was determined to be above 0.079 mg/L while the NOEC (72h) was determined at 0.013 mg/L test substance (Hoberg, 1996).

Toxicity towards microorganisms:

No substantial toxicity towards microorganims was observed. The 3h-EC50 towards microorganisms is > 20 mg/L (Drake, 2011).

To conclude, based on the acute toxicity results presented here algae appear to be the most sensitive species. The long-term toxicity results however indicate that the invertebrates are more sensitive towards the chemical in comparison to the algae. Therefore, the results obtained with the Daphnia are used for further risk assessment purposes and key value in determining the PNECs.