1,1,3,3-tetramethylbutyl 2-ethylperoxyhexanoate

Endpoint summary

Description of key information

Effects of 1,1,3,3-tetramethylbutyl peroxy-2-ethyl hexanoate on mortality, biomass and the reproductive potential of the earthworm species Eisenia fetida (Annelida, Lumbricidae) were determined according to OECD 222 (2016).

The study was conducted under static conditions over 8 weeks with the test item concentrations 31.25 – 62.5 – 125 – 250 – 500 mg/kg SDW. Each application rate was mixed into artificial soil containing 5 % peat. A control and a solvent control including untreated artificial soil was tested under the same conditions as the test item treatments.

Under the conditions of this study, the substance did not induce evident earthworm mortalities (< 10%) nor pathological symptoms or changes in the behaviour of adult earthworms in all test item concentrations. There were no statistically significant differences in earthworm body weights in the test item concentrations 31.25 to 500 mg/kg soil dry weight compared to the control. There were no statistically significant differences in earthworm reproduction in the treatment rates 31.25 to 250 mg/kg soil dry weight compared to the pooled control. However, at the test item concentration 500 mg/kg soil dry weight  the earthworm reproduction was statistically significantly reduced. NOEC is 250 mg/kg soil dw.

All other terrestrial studies are waived. 1,1,3,3-tetramethylbutyl peroxy-2-ethyl hexanoate is not directly applied to soil. Indirect exposure of soil will also be negligible due to the quick hydrolysis and the biodegradability. All three degradation products have low potential to adsorb to soil (log Kow -0.24 to 2.64) and are readily biodegradable. Soil is therefore not considered as compartment of concern.