Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Additional information

Acutely harmful to aquatic organisms.

The inhibition of the degradation activity of activated sludge is not anticipated when introduced in appropriate low concentrations.

Short-term aquatic data is available for all three trophic levels all showing toxicity within the same range. The algae species Selenastrum capricornutum was the most sensitive organism tested with an ErC50 value of 11.8 mg/L and a NOEC of 2.8 mg/L. Additional toxicity testing with three different fish species (O. mykiss, L. macrochirus and C. variegatus) and with the aquatic invertebrate Daphnia magna resulted in LC/EC50 values between 25 mg/L and 90 mg/L.

There are no guideline studies available which assess the test substance's chronic toxicity to fish. Thus, the assessment of the long-term toxicity has been covered with available data of structurally similar para-substituted phenols as well as with the results of the OECD Toolbox. Based on this data, the toxicity of the test substance is not expected to be more severe than that of p-tert-butylphenol (NOEC = 0.1 mg/L). In order to confirm these expectations, a long-term study with Daphnia magna has been conducted which resulted in a EC10 of 0.521 mg/L (NOEC = 1 mg/L).