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Environmental fate & pathways

Biodegradation in water: screening tests

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Administrative data

Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
key study
Study period:
16th July 1990 to 13th August 1990
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1996
Report Date:
1996

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)
Version / remarks:
The sealed vessel test is a CO2 production test based on OECD Guideline 301B. The test system is closed and is therefore suitable for the examination of volatile materials.
Principles of method if other than guideline:
The sealed vessel test is a CO2 production test based on OECD Guideline 301B. The test system is closed and is therefore suitable for the examination of volatile materials.
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
liquid
Specific details on test material used for the study:
TRASEOLIDE :
Lot No. / Sample Code : R485
Purity : 97% (total of Isomers); 84% (Main Peak)
Date of Expiry : Not known

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge (adaptation not specified)
Details on inoculum:
The inoculum was 10% by volume of activated sludge plant secondary effluent, filtered through a Whatman filter paper (541) to remove coarse particulate matter. The level of dissolved inorganic carbon was reduced by sparging the filtered effluent with nitrogen after prior adjustment of the pH to 6.5.
Duration of test (contact time):
28 d
Initial test substance concentration
Initial conc.:
10 mg/L
Based on:
other: Nominal concentration of Organic Carbon
Parameter followed for biodegradation estimationopen allclose all
Parameter followed for biodegradation estimation:
CO2 evolution
Parameter followed for biodegradation estimation:
inorg. C analysis
Remarks:
Dissolved Inorganic Carbon
Details on study design:
The test used was the sealed vessel test which is suitable for determining the ready and ultimate biodegradability of organic substances. The test was conducted in 160 mL vessels (hypovials) containing 100 mL mineral salts medium inoculated with secondary effluent and the respective test or reference substance. Multiple vessels are prepared per substance sealed with butyl rubber septa and an aluminium crimp seal. The headspace in each vessel has a volume of 60 mL and, when filled with air, contains approximately 6 times the mass of oxygen required for the complete oxidation of the test item.

The sealed vessels are incubated at 20 °C on a rotary shaker. At intervals during the 28 day test period (Day 3, 7, 10, 14, 17, 21, 24 and 28) a vessel is removed and concentration of carbon dioxide in the headspace gas determined. The seal is then broken and the concentration of inorganic carbon in the test medium is also determined. The total inorganic carbon in the vessel is calculated and corrected by subtracting the total inorganic carbon produced in the Control. The Control vessels were identical to the test vessels except for the omission of the test substance. From a knowledge of the initial organic carbon concentration added as a test substance, the extent of mineralisation can be determined.

Results and discussion

% Degradation
Key result
Parameter:
% degradation (CO2 evolution)
Value:
-6.6
Sampling time:
28 d

Applicant's summary and conclusion

Validity criteria fulfilled:
not specified
Interpretation of results:
not readily biodegradable
Conclusions:
TRASEOLIDE was not found to be Readily Biodegradable under the test conditions.

Biodegradation, based on evolved headspace CO2 and dissolved inorganic carbon was effectively zero on Day 28 (actual determined vs Control = - 6.6% (95% confidence interval : -9.0 to -4.2%).

Day % Biodegradation
3 9.3
7 -3.5
10 -7.6
14 -0.1
17 -1.1
21 3.3
24 0.0
28 -6.6
Executive summary:

TRASEOLIDE was not found to be Readily Biodegradable under the test conditions.

Biodegradation, based on evolved headspace CO2 and dissolved inorganic carbon was effectively zero on Day 28 (actual determined vs Control = - 6.6% (95% confidence interval : -9.0 to -4.2%).

Day              % Biodegradation

3                      9.3

7                     -3.5

10                     -7.6

14                     -0.1

17                     -1.1

21                     3.3

24                     0.0

28                     -6.6