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Environmental fate & pathways

Biodegradation in water: screening tests

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Description of key information

Hydrolysis product: Stearic acid: readily biodegradable

Key value for chemical safety assessment

Biodegradation in water:
readily biodegradable

Additional information

Studies on the biodegradability of stearoyl chloride are not available.

However, the test substance is expected to hydrolyse rapidly (t1/2 < 24 h) to form stearic acid. The biodegradability of stearic acid is assessed via a weight of evidence approach.

1) Stearic acid is readily biodegradable in a modified respirometric test with activated sludge from a wwtp treating predominantely industrial sewage (EU method, BASF AG, 1983).

2) Sodium stearate was proven to be readily biodegradable in a EU ring test (OECD 301F; Painter & King, 1982). This study record has a low reliability since the original report is not available.

3) Stearic acid was predicted to readily biodegradable based on the BIOWIN (v4.10) model (BASF SE, 2009). All modules of this program predicted a fast biodegradation with the final conclusion of ready biodegradability.

4) Stearic acid was also predicted to be readily biodegradable based on the OASIS Catalogic BOD Kinetic (OECD 301F) model (beta v05.06). The substance is within the application domain of the model. The degradation reached 80% after 28 d.

Based on all four evidences, stearic acid is assumed to be readily biodegradable.