1-Ethoxy-2,3-difluoro-4-[trans-4-(trans-4-propylcyclohexyl)-cyclohexyl]-benzene

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

2004-03-24 to 2004-05-21

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))

Deviations:

not specified

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): activated sludge, micro organisms from a domestic waste water treatment plant
- Origin: Municipal sewage treatment plant
-Conditioning: The activated sludge used for this study was washed by centrifugation and the supernatant liquid phase was decanted. The solid material was re-suspended in tap water and centrifuged again.This procedure was repeated twice. An aliquot of the final sludge suspension was weighed, dried and the ratio of wet sludge to its dry weight was determined. Based on this ratio, calculated aliquots of washed sludge suspension, corresponding to 1.5 g dry material per litre were mixed with test water.

Duration of test (contact time):

28 d

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Parameter followed for biodegradation estimation:

test mat. analysis

Details on study design:

According to guideline

Reference substance:

aniline

Preliminary study:

The biodegradation in % was calculated based on the ThOD of 3.394 mg O2/mg test item.

Key result

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

28 d

Key result

Parameter:

% degradation (test mat. analysis)

Value:

0

Sampling time:

28 d

Results with reference substance:

The reference item (Aniline) was sufficiently degraded to 61 % after 14 days and to 69 % after 28 days of incubation. The validity criterion that the degradation should be > 60 % after 14 d was fulfilled.

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

The degradation rate of the test material did not reach 60 % within the 10-day window and after 28 days of incubation. Thus, the test item is not readily biodegradable.

Executive summary:

Purpose

The test item was investigated for its ready biodegradability in a GLP study according to OECD TG 301C over a period of 28 days. The biodegradation was followed by the oxygen uptake of the microorganisms during exposure. As a reference item aniline was tested simultaneously under the same conditions as the test item and functioned as a procedure control. The chemical analysis of the test material was performed using HPLC.

 

Result

Biodegradation of test item

After correction of the mean biochemical oxygen demand of the inoculum controls at the end of the 28 -day exposure period a degradation of 0 % as found.

 

Biodegradation of aniline

The reference item was sufficiently degraded to 69 % after 14 days and to 75 % after 28 days of incubation, thus confirming the suitability of the used activated sludge inoculum.

 

Conclusion

The degradation rate of the test material did not reach 60 % within the 10 -day window and after 28 days of incubation. Thus the test item is not readily biodegradable.

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2007-04-04 to 2007-05-02

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.4-D (Determination of the "Ready" Biodegradability - Manometric Respirometry Test)

Version / remarks:

1992-07-31

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)

Version / remarks:

1992-07-17

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

The activated sludge used for this study was washed by centrifugation and the supernatant liquid phase was decanted. The solid material was resuspended in tap water and again centrifuged. This procedure was repeated twice. An aliquot of the final sludge suspension was weighed, dried and the ratio of wet sludge to its dry weight was determined. Based on this ratio, calculated aliquots of washed sludge suspension, corresponding to 1.5 g dry material per litre were mixed with test water and then aerated until use. The washed activated sludge was pre-incubated for 2 days under aeration.

- Source of activated sludge: Mirco organisms from domestic waste water treatment plant (sewage plant Rossdorf, Germany)

Duration of test (contact time):

28 d

Initial conc.:

102.4 mg/L

Based on:

test mat.

Initial conc.:

276 mg/L

Based on:

ThOD

Remarks:

of 2.677 mg O2/mg test item

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: reconstituted test water according to OECD TG 301 F
- Test temperature: 22 °C
- pH: 7.6 (start of test), 7.6-7.8 (end of test)
- pH adjusted: no
- Aeration of dilution water: refer to "Details on inoculum”
- Suspended solids concentration: refer to "Details on inoculum”
- Continuous darkness: yes

TEST SYSTEM
- Culturing apparatus: Manometric test system with test flasks containing a volume of 500 mL
- Number of culture flasks/concentration: 2 (test item and inoculum control), 1 (procedure, abiotic and toxicity control)
- Method used to create aerobic conditions: aeration until use
- Measuring equipment: Measurement of oxygen: daily determination of pressure in test flask using BSB/BOD-Sensor-System, Aqualytic, 63231 Neu Isenburg, Germany
- Test performed in closed vessels: yes
- Details of trap for CO2 and volatile organics: Evolved CO2 was absorbed on an aqueous solution (45 %) of potassium hydroxide.

SAMPLING
Not applicable

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes
- Abiotic sterile control: yes
- Toxicity control: yes

STATISTICAL METHODS: Not performed

Reference substance:

benzoic acid, sodium salt

Test performance:

Results of controls showed validity of the test performed.

Key result

Parameter:

% degradation (O2 consumption)

Value:

<= 3

Sampling time:

28 d

Details on results:

During the 28-day exposure period the max. degradation 3 % was determined for the test item.

Oxygen demand in the abiotic control was zero and thus, no correction of the test item degradation rates had to be done.

Results with reference substance:

The reference item was sufficiently degraded to a mean of 70 % after 4 days, and to a mean of 92 % after 28 days of incubation.

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

The degradation rate of the test material did not reach 60 % within the 10-day window and after 28 days of incubation. Thus, the test item is not readily biodegradable.

Executive summary:

Purpose

The test item was investigated for its ready biodegradability in a Manometric Respirometry Test over a period of 28 days. The biodegradation was followed by the oxygen uptake of the microorganisms during exposure. As a reference item sodium benzoate was tested simultaneously under the same conditions as the test item, and functioned as a procedure control.The GLP study was performed according to OECD TG 301F.

 

Result

Biodegradation of test item

During the 28-day exposure period the max. degradation 3 % was determined for the test item.

Oxygen demand in the abiotic control was zero and thus, no correction of the test item degradation rates had to be done. 

 

Biodegradation of Sodium Benzoate

The reference item was sufficiently degraded to a mean of 70 % after 4 days, and to a mean of 92 % after 28 days of incubation, thus confirming the suitability of the used activated sludge inoculum.

 

Biodegradation in the Toxicity Control

In the toxicity control containing both, the test item and the reference item, 34 % biodegradation was noted within 14 days and 35 % biodegradation was determined after 28 days of incubation. Thus, the test item can be assumed to be not inhibitory on the activated sludge micro organisms.

 

Conclusion

The degradation rate of the test material did not reach 60 % within the 10-day window and after 28 days of incubation. Thus, the test item is not readily biodegradable.

Description of key information

The test item was determined to be not readily biodegradable in an OECD 301F study. 

The test item was determined to be not readily biodegradable in an OECD 301C study. 

 

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Type of water:

freshwater

Additional information

Key study (OECD 301F)

The test item was investigated for its ready biodegradability in a Manometric Respirometry Test over a period of 28 days. The biodegradation was followed by the oxygen uptake of the microorganisms during exposure. As a reference item sodium benzoate was tested simultaneously under the same conditions as the test item, and functioned as a procedure control. The GLP study was performed according to OECD TG 301F. During the 28-day exposure period the max. degradation of 3 % was determined for the test item.  Oxygen demand in the abiotic control was zero and thus, no correction of the test item degradation rates had to be done. The reference item (sodium benzoate) was sufficiently degraded to a mean of 70 % after 4 days, and to a mean of 92 % after 28 days of incubation, thus confirming the suitability of the used activated sludge inoculum. In the toxicity control containing both, the test item and the reference item, 34 % biodegradation was noted within 14 days and 35 % biodegradation was determined after 28 days of incubation. Thus, the test item can be assumed to be not inhibitory on the activated sludge microorganisms. The degradation rate of the test material did not reach 60 % within the 10-day window and after 28 days of incubation. Thus, the test item is not readily biodegradable.

 

Supporting study (OECD 301C)

The test item was investigated for its ready biodegradability in a GLP study according to OECD TG 301C over a period of 28 days. The biodegradation was followed by the oxygen uptake of the microorganisms during exposure. As a reference item aniline was tested simultaneously under the same conditions as the test item and functioned as a procedure control. The chemical analysis of the test material was performed using HPLC. After correction of the mean biochemical oxygen demand of the inoculum controls at the end of the 28 -day exposure period a degradation of 0 % as found for the test item. The reference item (aniline) was sufficiently degraded to 69 % after 14 days and to 75 % after 28 days of incubation, thus confirming the suitability of the used activated sludge inoculum. The degradation rate of the test material did not reach 60 % within the 10 -day window and after 28 days of incubation. Thus, the test item is not readily biodegradable.