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Environmental fate & pathways

Biodegradation in water: screening tests

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Description of key information

The biodegradation of n-butyl-4,4 -bis(tert-butylperoxy)valerate totaled 52% after 28 days in the 28 -day modified Sturm test (OECD 301B). Therefore, this peroxide can be considered as inherently biodegradable.

Key value for chemical safety assessment

Biodegradation in water:
inherently biodegradable

Additional information

The ready biodegradability of n-butyl-4,4 -bis(tert-butylperoxy)valerate was evaluated using a 28 -day modified Sturm test according to OECD guideline no. 301 B under GLP requirements (L'Haridon, 2001).

The flasks of the test item obtained a peroxide concentration of 10 mg/L of TOC and inoculum. The inoculum consisted of sewage sludge sampled from the aeration tank of a sewage treatment plant and was aerated for 7 days. Inoculum concentration was 12.0 mg/L (dry weight) in all test vessels. CO2 scrubbed air was bubbled through the flasks for the 28 day test period.

The biodegradation of the test substance totaled 52 % after 28 days and thus it is considered as non readily biodegradable in the 28 -day modified Sturm test. All validity criteria were respected.

As indicated in the ECHA Guidance Chapter R.7B (Version 3.0 - Feb 2016 - page 209), when results of ready biodegradability tests indicate that the pass level criterion is almost fulfilled (i.e. ThOD of DOC slightly below 60% or 70% respectively) such results can be used to prove inherent biodegradability. Therefore, n-butyl-4,4 -bis(tert-butylperoxy)valerate can be considered as inherently biodegradable.