4'-trans-Butyl-[1,1'-bicyclohexyl]-4-on

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

26.02.-25-03.1992

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Name and location of sewage treatment plant where inoculum was collected: laboratory plant treating predominantly municipal sewage (treatment plant Neuenfelde)
- addition of 100 g standard soil from the Speyer region.
- Pre-treatment: filtration through rough flter
- Initial concentration: 3E+4 colony forming units/mL

Duration of test (contact time):

28 d

Initial conc.:

1.48 mg/L

Based on:

test mat.

Details on study design:

- Test temperature: 20 +- 1 °C
- control flask: destilled water with mineral nutrient solution without inoculum
- blind flask: destilled water with mineral nutrient solution with inoculum
- reference flask: a solution of sodium-n-dodecylsulfat with mineral nutrient solution and inoculum
- degradation test: a solution of the test item with mineral nutrient solution and inoculum
- inhibition test: a solution ofthe test item, sodium-n-dodecylsulfat with mineral nutrient solution and inoculum

The oxygen concentration of the test solutions was determined electrochemically after 0, 5, 15, 28 days.

Reference substance:

laurylsulfonate

Key result

Parameter:

% degradation (O2 consumption)

Value:

6

Sampling time:

28 d

Table 1: Results

	mg O2 after x dayys
Medium	Bottle	0 days	5 day	15 days	28 days
mineral nutrient solution without test item and inoculum	K1	9,01	8,99	8,95	8,92
mineral nutrient solution without test item and inoculum	K2	9,02	8,99	8,96	8,92
mineral nutrient solution without test item and inoculum	Mean	9,02	8,99	8,96	8,92
mineral nutrient solution without test item and with inoculum	B1	9,01	8,97	8,95	8,92
mineral nutrient solution without test item and with inoculum	B2	9,00	8,96	8,94	8,91
mineral nutrient solution without test item and with inoculum	Mean	9,01	8,97	8,95	8,92
mineral nutrient solution with test item and with inoculum concentration 1,58 mg/L	S1	9,00	8,88	8,74	8,64
mineral nutrient solution with test item and with inoculum concentration 1,48 mg/L	S2	9,01	8,88	8,77	8,62
mineral nutrient solution with test item and with inoculum concentration 1,48 mg/L	Mean	9,01	8,88	8,76	8,63
mineral nutrient solution with reference substance and with inoculum concentration 2,0 mg/L	R1	9,02	7,53	6,32	5,44
mineral nutrient solution with reference substance and with inoculum concentration 2,0 mg/L	R2	9,01	7,51	6,35	5,47
mineral nutrient solution with reference substance and with inoculum concentration 2,0 mg/L	Mean	9,02	7,52	6,34	5,46
mineral nutrient solution with test item (1,48 mg/L) reference substance (2,0 mg/L) and inoculum concentration	H1	9,00	7,52	6,33	5,64
mineral nutrient solution with test item (1,48 mg/L) reference substance (2,0 mg/L) and inoculum concentration	H2	9,00	7,55	6,37	5,64
mineral nutrient solution with test item (1,48 mg/L) reference substance (2,0 mg/L) and inoculum concentration	Mean	9,00	7,54	6,35	5,64

Table 2: Results of the closed bottle test

Substance	degradation after 5 days	degradation after 15 days	degradation after 28 days
Reference Substance	36%	65%	87%
Test item	2%	4%	6%

 

The test item was not determined to be readily biodegradable.

The test item showed weak inhibitory potential.

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

The test substance degraded to 6% within 28 days. Therefore, the substance is considered to be classified as "not readily biodegradable".

Executive summary:

A Closed Bottle Test on ready biodegradability was conducted according to OECD Guideline 301 D. The validity criteria was fulflilled, as the reference substance laurylsulfonate degraded to 87% after 28 days. The test substance was applied at 1.48 mg/L and degraded to 6% after 28 days. Therefore, the substance is considered be classified as "not readily biodegradable".

Description of key information

The test substance degraded to 6% within 28 days. Therefore, the substance is considered to be classified as "not readily biodegradable".

Key value for chemical safety assessment

Biodegradation in water:

not biodegradable

Type of water:

freshwater

Additional information

A Closed Bottle Test on ready biodegradability was conducted according to OECD Guideline 301 D. The validity criteria was fulflilled, as the reference substance laurylsulfonate degraded to 87% after 28 days. The test substance was applied at 1.48 mg/L and degraded to 6% after 28 days. Therefore, the substance is considered be classified as "not readily biodegradable".