(trans(trans))-4'-but-3-enyl-4-(4-methylphenyl)-bicyclohexyl

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:

Aug 16, 2000 - Sep 13, 2000

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

1997

Principles of method if other than guideline:

None

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: activated sludge, microorganisms from a domestic waste water treatment plant
- Origin: sewage plant Groß-Zimmern, Germany
- Concentration of sludge: 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 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.

Duration of test (contact time):

28 d

Initial conc.:

104 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: Reconstituted water according to OECD 301
- Test temperature: 21 – 22 °C
- pH: 7.6 (measured at the start of the test)
- pH adjusted: no
- Aeration of dilution water: yes
- Continuous darkness: yes
TEST SYSTEM
- Culturing apparatus: Manometric Test System with test flasks containing a volume of500mL
- Number of culture flasks/concentration: 2
- Measuring equipment: BSB/BOD-Sensor-System, Aqualytic, D-63263 Neu Isenburg, Germany
- Test performed in closed vessels due to significant volatility of test substance: yes
CONTROL AND BLANK SYSTEM
- Inoculum blank: inoculum and test medium
- Abiotic sterile control: test item, inoculum and test medium
- Toxicity control: test item, reference item, inoculum and test medium
- Procedure control: reference item, inoculum and test medium

Reference substance:

aniline

Test performance:

The validity criteria were met:
- Inoculum Control: The oxygen demand of the inoculum control (medium and inoculum) was 10 mg O2/L and thus not greater than 60 mg O2/L within 28 days.
- Toxicity control: In the toxicity control containing both, the test item and the reference item aniline, 29 % biodegradation was noted within 14 days and 32 % biodegradation was determined after 28 days of incubation. According to the test guidelines the test item can be assumed to be not inhibitory on the activated sludge microorganisms because degradation was > 25 % within 14 days.
- pH-Value: The pH-value of the test item flasks at the end of the test was pH 7.6 and thus within the range of pH 6.0 - 8.5.
- Reference Item: The reference item aniline was sufficiently degraded to 77 % after 14 days, and to 92 % after 28 days of incubation, thus, confirming the suitability of the used activated sludge inoculum.
- Test Item: The difference of duplicate values for the degradation of the test item at any time during the test was less than 20 %.

Key result

Parameter:

% degradation (O2 consumption)

Value:

ca. 2

Sampling time:

28 d

Details on results:

After correction of the mean biochemical oxygen demand of the inoculum controls at the end of the 28-day exposure period degradation rates of 2 % and 3 % were found. The test item was found to be not ready biodegradable under the test conditions within 28 days.The reference item Aniline was sufficiently degraded to 77 % after 14 days, and to 92 % after 28 days of incubation.The biodegradation in the toxicity control containing both, the test item and the reference item Aniline was determined to be 29 % within 14 days and 32 % biodegradation was determined after 28 days of incubation.

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

The test item was found to be not ready biodegradable under the test conditions within 28 days.

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 micro organisms during exposure. As a reference item Aniline was tested simultaneously under the same conditions as the test item, and functioned as a procedure control.

Result

Biodegradation of the test item

After correction of the mean biochemical oxygen demand of the inoculum controls at the end of the 28-day exposure period degradation rates of 2 % and 3 % were found.

Biodegradation of Aniline

The reference item Aniline was sufficiently degraded to 77 % after 14 days, and to 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 Aniline 29 % biodegradation was noted within 14 days and 32 % 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 test item was found to be not ready biodegradable under the test conditions within 28 days.

Description of key information

The ready biodegradability of the test substance was determined according to OECD 301 F. Within the study period of 28 days, a degradation of 2 - 3 % was determined for the test substance. Therefore, the test substance is considered to be not readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

not biodegradable

Type of water:

freshwater

Additional information

No sludge with test item was available. Read across to a structural analogous material was done instead. Please refer to section 13 for justification of the read-across.

The ready biodegradability of the test substance was determined according to OECD 301 F "Ready Biodegradability: Manometric Respirometry Test" under GLP conditions over a period of 28 days. The biodegradation was followed by the oxygen uptake of the micro-organisms during exposure. A measured volume of inoculated mineral medium, containing a known concentration of test substance ca. 105 mg/L as the nominal sole source of organic carbon, is stirred in a closed flask at a constant temperature 22 °C for up to 28 days. The amounts of test item and reference item were directly weighed into the test flasks. No emulsifiers or solvents were used, but the solutions were dispersed by stirring to achieve a homogeneous solution of the test item. The closed test flasks were incubated in a climatic chamber under continuous stirring. The consumption of oxygen was determined by measuring the change of pressure in the flasks. Evolved carbon dioxide was absorbed in an aqueous solution (45 %) of potassium hydroxide. The change of pressure in the test flasks was measured by means of a manometric method (BSB/BOD-Sensor-System, Aqualytic) each day. The temperature was measured each working day in the climatic chamber. pH-values were measured in all flasks at the start and end of the test using a pH-electrode WTW pH 340i. Degradation was followed by the determination of oxygen uptake and measurements were taken at frequent intervals to allow the identification of the beginning and the end of biodegradation. The oxygen uptake was calculated from the readings taken at regular and frequent intervals.  All validity criteria of the test method were met. As a reference item aniline was tested simultaneously under the same conditions as the test item, and functioned as a procedure control. The reference item aniline was sufficiently degraded to 77 % after 14 days, and to 92 % after 28 days of incubation (ThODNH4). The results, thus, confirms the suitability of the used activated sludge inoculum. In the toxicity control containing both, the test item and the reference item aniline, 29 % biodegradation was noted within 14 days and 32 % biodegradation was determined after 28 days of incubation. Thus, the test item can be assumed not to be inhibitory on the activated sludge micro-organisms. Within the study period of 28 days, a degradation of 2 - 3 % was determined for the test substance. Therefore, the test substance is considered to be not ready biodegradable (reference 5.2.1-1).