4-trans-(4-trans-Propylcyclohexyl)-cyclohexancarbonic acid

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:

1996-07-30 to 1996-08-27

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

Qualifier:

according to guideline

Guideline:

EU Method C.4-E (Determination of the "Ready" Biodegradability - Closed Bottle Test)

Version / remarks:

1992

Deviations:

no

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

- Name and location of sewage treatment plant where inoculum was collected: laboratory plant treating predominantly municipal sewage (südlicher Wupperverband)
- Pre-treatment: filtration through rough filter
- Initial concentration: 5 mL/L
- Pre-conditioning: aeration for 4 days

Duration of test (contact time):

28 d

Initial conc.:

2.9 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

- Test temperature: 20 ± 1 °C
- Test substance: 2 flasks
- Reference substance: 2 flasks
- Toxicity control: 2 flasks
- Abiotic control: 2 flasks
- Test substance application: direct weight

Reference substance:

aniline

Key result

Parameter:

% degradation (O2 consumption)

Value:

9

Sampling time:

28 d

Results with reference substance:

In the parallel approaches with the reference substance aniline, a degradation of 93 % was achieved after 14 days.

Degradation results, mean of 2 determinations [%]:

Control test	7 d	14 d	21 d	28 d
Test substance	2	5	4	9
Reference (aniline)	76	93	95	88
Toxicity control	30	38	41	41

 

Oxygen concentration of inoculum blank value: (mg O₂/L after x days)

 

Flask-Nr.	Day-0	Flask-Nr.	Day-7	Flask-Nr.	Day-14	Flask-Nr.	Day-21	Flask-Nr.	Day-28
1	9.33	3	8.96	5	8.82	7	8.72	9	8.65
2	9.30	4	8.90	6	8.78	8	8.72	10	8.69
Average Value	9.32		8.93		8.80		8.72		8.67

 

Oxygen concentration of the reference substance: (mg O₂/L after x days)

 

Flask-Nr.	Day-0	Flask-Nr.	Day-7	Flask-Nr.	Day-14	Flask-Nr.	Day-21	Flask-Nr.	Day-28
11	9.40	13	5.34	15	4.40	17	4.27	19	4.25
12	9.39	14	5.34	16	4.46	18	4.23	20	4.72
Average Value	9.40		5.34		4.43		4. 25		4.49

 

Oxygen concentration of the test item: (mg O₂/L after x days)

 

Flask-Nr.	Day-0	Flask-Nr.	Day-7	Flask-Nr.	Day-14	Flask-Nr.	Day-21	Flask-Nr.	Day-28
81	9.40	83	8.85	85	8.50	87	8.49	89	7.86
82	9.36	84	8.84	86	8.46	88	8.49	90	8.15
Average Value	9.38		8.85		8.48		8.49		8.01

 

Oxygen concentration of the toxicity control: (mg O₂/L after x days)

 

Flask-Nr.	Day-0	Flask-Nr.	Day-7	Flask-Nr.	Day-14	Flask-Nr.	Day-21	Flask-Nr.	Day-28
91	9.40	93	5.06	95	4.06	97	3.43	99	3.68
92	9.39	94	5.43	96	3.98	98	3.69	100	3.16
Average Value	9.40		5.25		4.02		3.56		3.42

 

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

After 28 days, 9% degradation was observed. Therefore, the test item is considered not to be readily biodegradable.

Executive summary:

The test item was investigated for its ready biodegradability in a Closed Bottle Test over a period of 28 days according to EU Guideline C.4-E. The test material was exposed to sewage sludge micro-organisms at a concentration of 2.9 mg/L with culture medium in sealed culture vessels in the dark at 20 ± 1°C for 28 days. The degradation of the test material was assessed by the determination of the amount of oxygen consumed. Control solutions with inoculum and the standard material, aniline, together with a toxicity control were used for validation purposes. The test material attained 9 % degradation after 28 days and therefore cannot be considered to be readily biodegradable. The reference substance aniline, degraded to 93 % after 14-days. In the toxicity control, more than 35 % degradation were obtained. Therefore, the test is considered to be valid.

Description of key information

Degradation of the test item was examined in a test according to EU Guideline C.4-E (Closed Bottle Test). After 28 days, 9 % degradation was observed (reference 5.2.1-1).

Key value for chemical safety assessment

Biodegradation in water:

not biodegradable

Type of water:

freshwater

Additional information

The test item was investigated for its ready biodegradability in a Closed Bottle Test over a period of 28 days according to EU Guideline C.4-E. The test material was exposed to sewage sludge micro-organisms at a concentration of 2.9 mg/L with culture medium in sealed culture vessels in the dark at 20 ± 1°C for 28 days. The degradation of the test material was assessed by the determination of the amount of oxygen consumed. Control solutions with inoculum and the standard material, aniline, together with a toxicity control were used for validation purposes. The test material attained 9 % degradation after 28 days and therefore cannot be considered to be readily biodegradable. The reference substance aniline degraded to 93 % after 14-days. In the toxicity control, more than 35 % degradation were obtained. Therefore, the test is considered to be valid.