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Environmental fate & pathways

Biodegradation in water: screening tests

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Description of key information

Benzyl butyl phthalate is readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:
readily biodegradable

Additional information

Data is available from multiple studies. All indicate that benzyl butyl phthalate biodegrades rapidly.

CITI Japan (1992) report that in an OECD 301C test benzyl butyl phthalate degraded by 81 % over 2 weeks. The innoculum was activated sludge. This value is used by the EU RAR to determine that the substance is readily biodegradable. This is used as a key study.

The two other tests which are of sufficient quality to be key studies are tests for inherent biodegrability.

An inherent biodegradability study by Saeger and Tucker (1976), with domestic sewage as the inoculum, showed >93% degradation of benzyl butyl phthalate within 24 hours. This near-guideline publication is used as a key study.

An inherent biodegradability study by Suggart et. al (1984) had adapted domestic sewage as the inoculum. Mean primary degradation was 77.7% with pooled phthalate acid ester inoculum. With inoculum adapted only to BBP, primary degradation was 97% and ultimate degradation was 88%. Therefore in the test system used, BBP was found to be extensively biodegradable. This near-guideline publication is used as a key study.

Hicks (1976) performed tests using the Thomspon-Duthie-Sturm procedure, the Semi-Continuous Activated Sludge Procedure and a River Die-Away procedure. All indicated a high biodegradability of the test substance. These results were used as supporting studies.