Octahydro-4,7-methano-1H-indene-5-methanol

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:

2017-10-11 to 2017-11-08

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:

adopted July 17, 1992

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

EEC Publication No. L 142/496, May 2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Batch No.of test material: P1114D01BA
- Expiration date of the lot/batch: July 2018
- Purity test date: 02.08.2017

Theoretical Oxygen Demand, ThOD_NH4: 2.887 mg oxygen per mg test item (calculated)

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: At 20 +- 5 °C, in the dark.

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):

- Species/Origin: Aerobic activated sludge, microorganisms from a domestic waste water treatment plant (Rossdorf, Germany).

- Conditioning, preparation and storage: Activated sludge used for this study was washed by centrifugation and the supernatant liquid phase was decanted. The solid material was re-suspended in test water and centrifuged again. This procedure was done three times. The sediment of the last washing was re-suspended in test water and aerated until use. 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 3.5 g dry material per litre were mixed with test water and aerated overnight. This suspension was used for the experiment.

- Concentration of sludge: stock suspension of 3.5 g/L on dry matter base - final sludge concentration in test flasks: 28.7 mg sludge/L

Duration of test (contact time):

28 d

Initial conc.:

>= 102.5 - <= 102.9 mg/L

Based on:

test mat.

Initial conc.:

>= 295.8 - <= 297 mg/L

Based on:

ThOD

Remarks:

ThOD_NH4

Parameter followed for biodegradation estimation:

O2 consumption

Remarks:

The biodegradation was followed by the oxygen uptake of the microorganisms during exposure.

Details on study design:

TEST CONDITIONS
- Composition of medium: Mineral medium was prepared from stock solutions of appropriate concentrations of mineral components, namely, potassium and sodium phosphates plus ammonium chloride, calcium chloride, magnesium sulphate and iron (III) chloride, as described in the OECD Guideline.
- Test temperature: 22°C +- 1°C
- pH: 7.8 (at the end of the test); 7.6 (at the beginning of the test)
- pH adjusted: yes; pH was set to 7.4 -.7.5 with hydrochloric acid
- Suspended solids concentration: final sludge concentration in test flasks 28.7 mg sludge/L
- Continuous darkness: yes


TEST SYSTEM
- Number of flasks/concentration: Two test flasks were used with 25.0 and 25.1 mg per flask, 2 mL activated sludge per flask (3.5 g/L) and 242 mL mineral medium.
- Measuring equipment: The test flasks were closed gas-tight by a measuring head.
- Other: 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.


SAMPLING
- Sampling frequency/method: The change of pressure in the test flasks was measured by means of a manometric method (BSB/BOD-Sensor-System, Aqualytic Dortmund, Germany) each day.



CONTROL AND BLANK SYSTEM
- Inoculum blank: Two flasks were prepared with 2 mL activated sludge and 242 mL mineral medium per flask.
- Abiotic sterile control: One flask with 24.8 mg test item, 5 mL copper sulphate (stock solution of 1g/L) and 239 mL mineral medium.
- Toxicity control: One flask with 25.1 mg test item, 24.8 mg sodium benzoate, 2 mL activated sludge and 242 mL mineral medium.
- Other: One flask for the procedure control with 25.2 mg sodium benzoate, 2 mL acvitated sludge and 242 mL mineral medium.

Reference substance:

benzoic acid, sodium salt

Key result

Parameter:

% degradation (O2 consumption)

Value:

>= 0 - <= 0

St. dev.:

0

Sampling time:

28 d

Details on results:

The criterion for ready biodegradability under the conditions of a manometric respirometry test is the degradation of the test item of at least 60%, reached within a 10-day window; the 10-day window starts when the degradation of the test item reaches at least 10% degradation.
TCD Alcohol M never reached 10% biodegradation. The mean biodegradation at test end after 28 days was 0% (ThOD_NH4).
Therefore, TCD Alcohol M is considered to be not readily biodegradable based on ThOD_NH4.

The reference item sodium benzoate was sufficiently degraded to 73% after 14 days and to 84% after 28 days of incubation, thus confirming the suitability of the aerobic activated sludge inoculum used.

Based on the results of the toxicity control containing test item and reference item at the same concentrations as provided in the test and reference flasks, the test item was not inhibitory with regard to inhibition of microorganism responsible for biodegradation of the reference compound.
However, absolute O2-demand in inoculum control flasks was between 2 and 4 times higher compared to the test item flasks. This indicates microorganism toxicity and may affect microorganisms necessary for degradation of the test item. As a consequence, lack of biodegradation of the test item due to microorganism toxicity at the concentration tested (103 mg/L) cannot be excluded.

Results with reference substance:

The reference item sodium benzoate was sufficiently degraded to 73% after 14 days and to 84% after 28 days of incubation, thus confirming the suitability of the aerobic activated sludge inoculum used.

Raw data on biological oxygen demand obtained during the study:

Cumulative Biochemical Oxygen Demand (mg O2/L) in Test Flasks during the Test Period of 28 days - Flasks

• 1/2: test item flasks, ca. 103 mg/L test item
• 3/4: inoculum control flasks
• 5: reference flask: ca. 102.5 mg/L sodium benzoate
• 6: abiotic control
• 7: toxicity control, containing both, ca. 103 mg/L test item and ca. 102.5 mg/L sodium benzoate

Comparing absolute oxygen demand of test item flasks 1/2 with inoculum control flasks 3/4 indicates test item toxicity, because oxygen demand during days 1 to 15 is pronouncedly lower in flasks 1/2 containing the test item. Degradation in flask 7 seems to be solely due to degradation of the reference item sodium benzoate and is not inhibited by the test item as becomes obvious upon comparison with flask 5 containing the reference item, only.

Time				Flask No.
(days)	1	2	3	4	5	6	7
1	0	0	0	0	35	0	40
2	0	0	5	5	65	0	70
3	0	0	5	5	75	0	80
4	0	0	5	5	85	0	125
5	5	5	10	10	95	0	130
6	5	5	10	10	105	0	135
7	5	5	10	10	120	0	135
8	5	5	10	10	125	0	140
9	5	5	15	15	130	0	140
10	5	5	15	15	130	0	145
11	5	5	15	15	130	0	145
12	5	5	15	15	140	0	145
13	10	5	15	15	145	0	145
14	10	5	20	20	145	0	145
15	10	5	20	20	145	0	145
16	10	5	20	20	150	0	150
17	15	5	20	20	150	0	150
18	15	5	20	20	150	0	150
19	15	5	20	20	155	0	150
20	15	5	20	20	155	0	155
21	15	5	20	20	160	0	155
22	15	5	20	20	160	0	155
23	15	5	20	20	160	0	160
24	15	5	20	20	160	0	165
25	15	5	20	20	160	0	170
26	15	5	20	20	160	0	175
27	20	10	20	20	165	0	175
28	20	10	20	20	165	0	175

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

The criterion for ready biodegradability under the conditions of a manometric respirometry test is the degradation of the test item of at least 60%, reached within a 10-day window; the 10-day window starts when the degradation of the test item reaches at least 10% degradation.
TCD Alcohol M never reached 10% biodegradation. The mean biodegradation at test end after 28 days was 0% (ThODNH4).
Therefore, TCD Alcohol M is considered to be not readily biodegradable based on ThOD_NH4. Lack of biodegradability due to microorganism toxicity of the test item at the applied concentration cannot be excluded.

Executive summary:

The test item TCD Alcohol M (initial concentration: 102.7 mg/L, two replicates) was investigated compliant with GLP for its ready biodegradability in a manometric respirometry test according to OECD 301F over a period of 28 days. The biodegradation was followed by the oxygen uptake of the microorganisms during exposure and comparison with the theoretical biological oxygen demand (ThOD). As a reference item sodium benzoate was tested simultaneously under identical conditions (procedural control). Replicate inoculum controls, an abiotic control as well as a toxicity control (one flask) containing test item and reference item at the same concentrations as provided in test and reference item flasks were set up and run in parallel. The test met all validity criteria as given in OECD guideline 301.

Under the test conditions, TCD Alcohol M never reached 10% biodegradation. The mean biodegradation at test end after 28 days was 0% (ThOD_NH4). Biodegradation of the reference item demonstrated proper functioning of the test system (biodegradation extent 73% after 14 days and 84% after 28 days). As such, the test item proved to be not readily biodegradable under the conditions of this test.

Based on the results of the toxicity control containing test item and reference item at the same concentrations as provided in the test and reference flasks, the test item was not inhibitory with regard to microorganisms responsible for biodegradation of the reference compound.

However, the absolute O2-demand during days 1 to 15 in inoculum control flasks was between 2 and 4 times higher compared to the test item flasks. This indicates microorganism toxicity and may affect microorganisms necessary for degradation of the test item. As a consequence, lack of biodegradation of the test item due to microorganism toxicity at the concentration tested (103 mg/L) cannot be excluded.

Description of key information

Not readily biodegradable (OECD 301 F; GLP): <10 % within 28 days based on biological oxygen demand relative to theoretical oxygen demand (ThOD) of the test item.

Lack of biodegradability due to microorganism toxicity of the test item at the applied concentration (ca. 103 mg/L) cannot be excluded.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Additional information

The test item TCD Alcohol M (initial concentration: 102.7 mg/L, two replicates) was investigated compliant with GLP for its ready biodegradability in a manometric respirometry test according to OECD 301F over a period of 28 days. The biodegradation was followed by the oxygen uptake of the microorganisms during exposure and comparison with the theoretical biological oxygen demand (ThOD). As a reference item sodium benzoate was tested simultaneously under identical conditions (procedural control). Replicate inoculum controls, an abiotic control as well as a toxicity control (one flask) containing test item and reference item at the same concentrations as provided in test and reference item flasks were set up and run in parallel. The test met all validity criteria as given in OECD guideline 301.

 

Under the test conditions, TCD Alcohol M never reached 10% biodegradation. The mean biodegradation at test end after 28 days was 0% (ThOD_NH4). Biodegradation of the reference item demonstrated proper functioning of the test system (biodegradation extent 73% after 14 days and 84% after 28 days). As such, the test item proved to be not readily biodegradable under the conditions of this test.

 

Based on the results of the toxicity control containing test item and reference item at the same concentrations as provided in the test and reference flasks, the test item was not inhibitory with regard to microorganisms responsible for biodegradation of the reference compound.

However, the absolute O2-demand during days 1 to 15 in inoculum control flasks was between 2 and 4 times higher compared to the test item flasks. This indicates microorganism toxicity and may affect microorganisms necessary for degradation of the test item. As a consequence, lack of biodegradation of the test item due to microorganism toxicity at the concentration tested (103 mg/L) cannot be excluded.