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Environmental fate & pathways

Biodegradation in water: screening tests

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Reference
Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
key study
Study period:
12 June to 22 July 2013
Reliability:
1 (reliable without restriction)
Qualifier:
according to guideline
Guideline:
OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)
Deviations:
no
GLP compliance:
yes
Specific details on test material used for the study:
The carbon content of n-Butyl-3-hydroxybutyrate was calculated based on information provided by the sponsor and has a value of 60%
Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, non-adapted
Details on inoculum:
Cambridge Seage Treatment Works, Cowley Road, Cambridge CB24 8SW, UK
Duration of test (contact time):
28 d
Initial conc.:
50.16 mg/L
Based on:
test mat.
Parameter followed for biodegradation estimation:
CO2 evolution
Reference substance:
acetic acid, sodium salt
Test performance:
Test met all validlity criteria and the reference material degradation was 87% on day 29.
Key result
Parameter:
% degradation (CO2 evolution)
Value:
83
Sampling time:
28 d
Parameter:
% degradation (CO2 evolution)
Value:
91
Sampling time:
29 d
Details on results:
10% degradation was achieved after approximately 1.5 days, and 60% was reached on day 8, n-Butyl-3-hydroxybutryate therefore easily achieved the 10-day window.
Validity criteria fulfilled:
yes
Interpretation of results:
readily biodegradable
Conclusions:
n-Butyl-3 -hydroxybutyrate gave a positive result (>60% degradation relative to the ThCO2 value) with a maximum of 91% recorded on day 29. It may therefore, be concluded that there is a potential for biodegradation under environmental conditions.
Executive summary:

A Ready Biodegradability test was conducted with n-Butyl-3 -hydroxybutyrate following OECD 301B (CO2 Evolution Test). The test material was reported to meet the 10 -day window criterion with 10% degradation on approximately 1.5 days and 60% by day 8. The final percent degradation was 83% on day 28 and 91% on day 29. Therefore, n-Butyl-3 -hydroxybutyrate is considered to be readily biodegradable.

Description of key information

n-Butyl-3 -hydroxybutyrate gave a positive result (>60% degradation relative to the ThCO2 value) with a maximum of 91% recorded on day 29. It may therefore, be concluded that there is a potential for biodegradation under environmental conditions.

Key value for chemical safety assessment

Biodegradation in water:
readily biodegradable
Type of water:
freshwater

Additional information