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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
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: GLP compliant, guideline study, available as unpublished report, acceptable with restrictions
Qualifier:
according to guideline
Guideline:
OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)
Deviations:
not specified
GLP compliance:
yes
Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, non-adapted
Details on inoculum:
non adapted domestic sludge obtained from the Marl-Ost municipal sewage plant. The bacterial count of the sewage was 72 X 104 CFU/ml. Aerated at 21.4°C (mean)
Duration of test (contact time):
29 d
Initial conc.:
21.4 mg/L
Based on:
test mat.
Initial conc.:
21.5 mg/L
Based on:
test mat.
Details on study design:
Test vessels: approx. 5000ml Woulff Flasks.
- 2 vessels without the test item and with inoculum (blank batches)
- 1 vessel containing control item and inoculum (control batch)
- 2 vessels containing test item and inoculum (test item batches)

Carbon analysis performed by AS analysis division. C content 69.8%
TIC determined after 0, 2, 5, 8, 12, 19, 22, 28 and 29 days in duplicate. CO2 content measured via TIC analysis in a carbon analyser.
Reference substance:
other: sodium benzoate
Preliminary study:
No data
Test performance:
No data
Key result
Parameter:
% degradation (CO2 evolution)
Value:
-6
Sampling time:
28 d
Details on results:
Negative value for % degradation due to mathematical calculations.
Results with reference substance:
Degradation of the control item: 95% after 28 days and therefore the inoculum had a sufficient biological activity
Validity criteria fulfilled:
yes
Remarks:
Cumulative evolution of CO2 in the blank batch: 19.95mg/L (does not exceed 40 mg/L))
Interpretation of results:
not readily biodegradable
Conclusions:
Tris(triphenylphosphine)rhodium(1)chloride is not biodegradable.
Executive summary:

Biodegradation was assessed in a GLP-compliant study following OECD 301B (Enste-Diefenback 2016) using activated, non-adapted sludge. Test concentrations of 21.4 mg/L and 21.5 mg/L (test item), corresponding to 14.9 mg C/L and 15.0 mg C/L, respectively, were used. Blank controls and reference item controls were included in the study. The test item degraded by -6% over 28 days, the negative value is due to mathematical calculations. Tris(triphenylphosphine)rhodium(1)chloride is not biodegradable.

Description of key information

Tris(triphenylphosphine)rhodium(1)chloride is not biodegradable.

Key value for chemical safety assessment

Biodegradation in water:
under test conditions no biodegradation observed

Additional information

Biodegradation was assessed in a GLP-compliant study following OECD 301B (Enste-Diefenback 2016) using activated, non-adapted sludge. Test concentrations of 21.4 mg/L and 21.5 mg/L (test item), corresponding to 14.9 mg C/L and 15.0 mg C/L, respectively, were used. Blank controls and reference item controls were included in the study. The test item degraded by -6% over 28 days, the negative value is due to mathematical calculations. Tris(triphenylphosphine)rhodium(1)chloride is not biodegradable.