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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Two 96h acute fish studies are available, however only one is considered valid as it was performed under semi-static conditions with analytical verification of the test solutions. The 96h-LC50 for this study was 1.6 mg/L based on measured concentrations.

One 48h acute study with Daphnia magna is available.The reported biological results were based on the mean measured test item concentrations. The 24- and 48- hour EC50s of the test item was calculated to be 11 mg/L with 95% Confidence limits of 7.7 and 16 mg/L.

Two studies on algae are available. One study on freshwater algae performed under GLP with measured concentrations of the parent compound is considered reliable.

The 72h-ErC50 for algae based on geomean measured concentrations is 0.8 mg/L, the ErC10 is 0.44 mg/L (geomean measured).


One chronic fish study is available. A study was performed to assess the effects of the test item on the early-life stages of the fathead minnow (Pimephales promelas) according to OECD guideline 210. No effects were found up to 0.072 mg/L. Post hatch survival turned out to be the critical endpoint in this study with an LC10 of 0.101 mg/L (geometric mean measured concentration).

The chronic toxicity to  Daphnia magna  was determined in a 21 -day semi-static test according to OECD guideline 211.

No significant effects were found up to 0.44 mg/L (TWA, equal to 1.0 mg/L nom.) on reproduction and parental length and weight. NOEC for these endpoints is equal to 0.44 mg/L (TWA).

The lowest EC10was found for reproduction and was 0.49 mg/L (TWA).


In order to predict effects of tert-butyl-peroxybenzoate in biological wastewater treatment plants, an activated sludge respiration inhibition test was performed according to the OECD 209 and the EEC Method C.11 Guidelines.

The 30min-EC50 of tert-butyl-peroxybenzoate for activated sludge is 43 mg/L. The 30min-EC10 is 6 mg/L.

Additional information