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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

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Description of key information

72h-EC10and 72h-EC50 for freshwater algae were determined to be 160.5 µg/L and 421.5 µg/L, respectively according to OECD 201 guideline.

Key value for chemical safety assessment

EC50 for freshwater algae:
421.5 µg/L
EC10 or NOEC for freshwater algae:
160.5 µg/L

Additional information

The acute toxicity of n-butyl-4,4 -bis(tert-butylperoxy)valerate to freshwater algae was tested using OECD guideline 201 under GLP conditions (Chastenet, 2017).

The concentrations that result in a 10 and 50% reduction in growth rate (72h-ErC10 and 72h-ErC50, respectively) were determined.

As the test item was known to be difficult to dissolve, tests solutions were prepared from dilutions of a saturated solution prepared using slow-stirring conditions described in the OECD 123 guideline.

Chemical analysis of the test item showed the instability of the substance over the 72-hour test period. Based on these results, the exposure concentrations were based on the geometric mean of measured concentrations: 72h-EC10and 72h-EC50 were determined to be 160.5 µg/L and 421.5 µg/L, respectively. The definitive test met the validity criteria of the test guideline.