1,1'-Biphenyl, 4-methyl-4'-(3E)-3-penten-1-yl-

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:

from 2005-09-29 to 2006-02-06

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:

1992

Deviations:

no

Principles of method if other than guideline:

None

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, adapted

Details on inoculum:

- Source of inoculum/activated sludge: activated sludge, microorganisms from a domestic waste water treatment plant
- Origin: sewage plant Darmstadt, Germany
- Method of cultivation: 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: according to guideline OECD 301 F (1992)
- Additional substrate: no
- Solubilising agent: no
- Test temperature: at room temperature
- pH: 7.5 - 7.8 (measured at the end of the test)
- pH adjusted: no
- Aeration of dilution water: yes
- Suspended solids concentration: 30 mg/L
- Continuous darkness: yes

TEST SYSTEM
- Culturing apparatus: Karlsruher flasks of 250 mL volume with glass stoppers
- Number of culture flasks/concentration:
2 bottles containing the test item and inoculum
1 bottles containing the reference item aniline and inoculum (procedure control)
2 bottles containing only inoculum (inoculum control)
1 bottles containing the test item, reference item aniline and inoculum (toxicity control)
- Measuring equipment:The change of pressure in the test flasks was measured by means of a manometric method (BSB/BOD-Sensor-System, Aqualytic, 63231 Neu Isenburg, Germany) each day.
- Test performed in closed vessels due to significant volatility of test substance: no
- Test performed in open system: yes

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

Reference substance:

aniline

Test performance:

- Toxicity control: In the toxicity control containing both, the test item and the reference item aniline, 40 % biodegradation was noted within 14 days and 49 % biodegradation was determined after 28 days of incubation. If nitrification occurs, the biodegradation of the toxicity control aniline was determined to be 35 % after 14 days and 43 % at the end of the test. According to the test guidelines the test item can be assumed to be not inhibitory on the activated sludge micro-organisms because degradation was > 25 % within 14 days.
- Inoculum Control: The oxygen demand of the inoculum control (medium and inoculum) was 30 mg O2/L (mean) and thus not greater than 60 mg O2/L within 28 days.
- The pH-value of the test item flasks at the end of the test was within the range of pH 6.0 - 8.5.
- Procedure control: The reference item aniline was sufficiently degraded to 106 % after 14 days, and to 118 % after 28 days of incubation. The percentage degradation of the reference item aniline reached the level for ready biodegradability (> 60 %) within 6 days.
The validity crietria were met.

Key result

Parameter:

% degradation (O2 consumption)

Value:

ca. 2

Sampling time:

28 d

Details on results:

Under the test conditions the percentage biodegradation of the test material reached in the mean 2 % after 28 days of incubation.

Results with reference substance:

The reference item aniline was sufficiently degraded to 106 % after 14 days, and to 118 % after 28 days of incubation (ThODNH4).If nitrification occurs (ThODNO3), Aniline was degraded by 82 % after 14 days and 92 % at the end of the test. The percentage biodegradation of the reference item confirms the suitability of the used activated sludge inoculum.

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

The ready biodegradability of the test item was determined according to OECD 301 F "Ready Biodegradability: Manometric Respirometry Test". Within the study period of 28 days, a degradation of 2 % was determined for the test substance. Therefore, the test substance is considered to be not ready biodegradable.

Executive summary:

The ready biodegradability of the test item 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. 25 mg/L as the nominal sole source of organic carbon, is stirred in a closed flask at a constant temperature (21.6 - 21.7 °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 is followed by the determination of oxygen uptake and measurements are taken at frequent intervals to allow the identification of the beginning and end of biodegradation. The oxygen uptake is 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 106 % after 14 days, and to 118 % after 28 days of incubation (ThODNH4). If nitrification occurs (THODNO3), aniline was degraded by 82 % after 14 days and 92 % at the end of the test. The results thus confirming the suitability of the used activated sludge inoculum. In the toxicity control containing both, the test item and the reference item aniline, 40 % biodegradation was noted within 14 days and 49 % biodegradation was determined after 28 days of incubation. If nitrification occurs, the biodegradation of the toxicity control aniline was determined to be 35 % after 14 days and 43 % at the end of the test. 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 % was determined for the test substance. Therefore, the test substance is considered to be not ready biodegradable.

Description of key information

The ready biodegradability of the test item was determined according to OECD 301 F "Ready Biodegradability: Manometric Respirometry Test" (reference 5.2.1-1). Within the study period of 28 days, a degradation of 2 % was determined for the test substance. Therefore, the test substance is considered to be not ready biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Type of water:

freshwater

Additional information

The ready biodegradability of the test item 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. 25 mg/L as the nominal sole source of organic carbon, is stirred in a closed flask at a constant temperature (21.6 - 21.7 °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 is followed by the determination of oxygen uptake and measurements are taken at frequent intervals to allow the identification of the beginning and end of biodegradation. The oxygen uptake is 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 106 % after 14 days, and to 118 % after 28 days of incubation (ThODNH4). If nitrification occurs (THODNO3), aniline was degraded by 82 % after 14 days and 92 % at the end of the test. The results thus confirming the suitability of the used activated sludge inoculum. In the toxicity control containing both, the test item and the reference item aniline, 40 % biodegradation was noted within 14 days and 49 % biodegradation was determined after 28 days of incubation. If nitrification occurs, the biodegradation of the toxicity control aniline was determined to be 35 % after 14 days and 43 % at the end of the test. 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 % was determined for the test substance. Therefore, the test substance is considered to be not ready biodegradable.