[3aR-(3aα,5aβ,9aα,9bβ)]decahydro-3a,6,6,9a-tetramethylnaphth[2,1-b]furan-2(1H)-one

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

other information

Study period:

Not reported

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

non-GLP study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

[3aR-(3aα,5aβ,9aα,9bβ)]decahydro-3a,6,6,9a-tetramethylnaphth[2,1-b]furan-2(1H)-one

EC Number:

209-269-0

EC Name:

[3aR-(3aα,5aβ,9aα,9bβ)]decahydro-3a,6,6,9a-tetramethylnaphth[2,1-b]furan-2(1H)-one

Cas Number:

564-20-5

Molecular formula:

C16H26O2

IUPAC Name:

[3aR-(3aα,5aβ,9aα,9bβ)]decahydro-3a,6,6,9a-tetramethylnaphth[2,1-b]furan-2(1H)-one

Test material form:

solid: particulate/powder

Details on test material:

- Storage conditions: stored at approximately 4°C (refrigerator) in the dark under N2 conditions.

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

A mixed population of activated sewage sludge micro-organisms (Test System) was obtained on January 30th, 2017 from the secondary treatment stage of the sewage treatment plant at Villette (STEP Villette, av. de Thônex 105, 1226 THONEX (Geneva, Switzerland)), which treats predominantly domestic sewage.
The culture medium used in this study (see Appendix 1) was that recommended in the OECD Guideline N° 301F.

The sample of activated sewage sludge was maintained on continuous aeration upon receipt. A sample of the activated sewage sludge was washed three times by settlement (centrifuge: Heittich rotenta 460 RS) and suspension in culture medium. To remove any excessive amounts of Dissolved Organic Carbon (DOC) that may have been present, the solution was stirred and maintained on with pure oxygen at room temperature. Determination of dry weight is made to inoculate final solution with 30mg/L dry weight activated sludge.

Duration of test (contact time):

60 d

Initial test substance concentration

Initial test substance concentration 1

Initial conc.:

102.5 mg/L

Initial test substance concentration 2

Initial conc.:

97.5 mg/L

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

The test material (test 1) was dispersed directly in culture medium. An amount of test material (20.5mg) was dispersed in 200mL of culture medium inoculated to give the test concentration of 102.5mg /L.
The test material (test 2) was dispersed directly in culture medium. An amount of test material (19.5mg) was dispersed in 200mL of culture medium inoculated to give the test concentration of 97.5mg /L.
Analysis of the concentration, homogeneity and stability of the test material in the test solutions were not appropriate to the test guideline.

The culture medium used in this study was that recommended in the OECD Guideline N° 301F.

On Day 0, the following solutions were inoculated in 1000mL glass culture vessels (total volume when full 1145mL) each containing 200mL of solution:

 A control, in duplicate, consisting of inoculated culture medium.

 The test material (SCLAREOIDE NEW CRIST), in duplicate, in inoculated culture medium.

 The reference material (Sodium Benzoate) in inoculated culture medium.

 The test material and the reference material in inoculated culture medium as a toxicity control.

The system consists of a sample flask sealed by a sensor head/CO2 trap in a temperature controlled incubator. The samples were stirred for the duration of the study with a magnetically coupled stirrer.

As biodegradation progresses, the micro-organisms convert oxygen to carbon dioxide which is absorbed into NaOH causing a net reduction in gas pressure within the sample flask.

WTW oxitopC calculate automatically the consumption of oxygen.

The test was conducted in diffuse light at a temperature of 22°C +/- 1°C.

The daily Biochemical Oxygen Demand (BOD) values for the control, test and reference materials and the toxicity control have available below.

The BOD was adjusted automatically at the temperature measurement.

The total amount of oxygen required to oxidise a chemical completely is calculated from the molecular formula (assuming no nitrification occurs) and expressed as mg oxygen required per mg test item as described in the OECD Guideline N° 301F.
The biodegradability exerted after each period was calculated as :

BOD= (mgO2/luptake by test substance -O2/l uptake by blank)/ mg test substance/lin vessel = mg02/mg test substance

The percentage biodegradation of the test items and of the reference item sodium benzoate was calculated as:
% biodegrdation= BOD(mgO2/mg test substance)/ThOD(mgO2/mg test substance) x100

Validation criteria

A test is considered valid if the difference of extremes of replicate values of the removal of the test chemical at the plateau, at the end of the test or at the end of the 10-d window, as appropriate, is less than 20%, and if the percentage degradation of the reference compound has reached the pass levels by day 14. If either of these conditions is not met, the test should be repeated. Because of the stringency of the methods, low values do not necessarily mean that the test substance is not biodegradable under environmental conditions, but indicates that more work will be necessary to establish biodegradability.

The BOD of the inoculated culture control medium (control) is normally 20 to 30mgO2/L and should not exceed 60mgO2/L after 28 days. Value higher than 60mgO2/L requires critical examination of the data and experimental technique. If the pH value is outside the range 6-8.5 and the oxygen consumption by the test substance is less than 60%, the test should be repeated with a lower concentration of test substance.

The results of the degradation test are considered valid if in the same test the reference material yields  60% degradation by Day 14.

The test material may be considered to be readily biodegradable if  60% degradation is attained after 28 days. This level of degradation must be reached within 10 days of biodegradation exceeding 10%.

The toxicity control should attain 25% degradation by Day 14 for the test material to be considered as non-inhibitory.

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

Test performance:

The test material (test 1) attained 45% degradation after 28 days, 62% degradation after 60 days.
The test material (test 2) attained 61 % degradation after 28 days days and didn’t satisfy the 10-day window validation criterion, 72% degradation after 60 days.
Therefore the test material cannot be considered to be readily biodegradable under the strict terms and conditions of OECD Guideline N° 301F.

The toxicity test attained 49% degradation after 28 days thereby confirming that the test material was not toxic to the sewage treatment micro-organisms used in the study.
Sodium Benzoate attained 78 % degradation after 28 days thereby confirming the suitability of the inoculum and test conditions.

% Degradation

% Degradation 1

Key result

Parameter:

% degradation (O2 consumption)

Remarks:

test 1

Value:

45

Sampling time:

28 d

Remarks on result:

other: 62% after 60 days

% Degradation 2

Key result

Parameter:

% degradation (O2 consumption)

Remarks:

test 2

Value:

61

Sampling time:

28 d

Remarks on result:

other: 72% after 60 days

Details on results:

pH comprised between 7.37 and 7.63

BOD5 / COD results

Results with reference substance:

Sodium Benzoate attained 78 % degradation after 28 days thereby confirming the suitability of the inoculum and test conditions.

Any other information on results incl. tables

Table 5.2.1/1: Cumulative Biochemical Oxygen Demand (mg O2/L) in test flask

days	min	bl1	bl2	test1	test2	reference	toxicity	abiotic
0	0	0	0	0	0	0	0	0
2	2880	6.2	0	6.2	6.2	80.6	86.8	0
4	5760	6.2	0	6.2	6.2	118	118	6.2
6	8640	6.2	6.2	31	55.8	130	136	6.2
8	11520	6.2	6.2	49.6	80.6	136	167	6.2
10	14400	12.4	6.2	62	99.3	130	186	0
12	17280	12.4	6.2	74.4	118	136	205	0
14	20160	12.4	12.4	86.8	130	143	223	6.2
16	23040	6.2	12.4	93.1	136	155	242	6.2
18	25920	18.6	18.6	112	155	149	242	0
20	28800	12.4	12.4	112	155	161	261	6.2
22	31680	18.6	24.8	130	167	161	273	12.4
24	34560	18.6	24.8	136	174	167	279	12.4
26	37440	24.8	24.8	143	186	161	279	6.2
28	40320	18.6	24.8	149	186	167	285	6.2
30	43200	18.6	24.8	155	192	161	292	6.2
32	46080	18.6	24.8	155	199	167	298	6.2
34	48960	24.8	24.8	161	205	161	298	6.2
36	51840	18.6	24.8	161	205	167	304	6.2
38	54720	24.8	24.8	167	217	167	310	6.2
40	57600	24.8	24.8	174	211	161	310	6.2
42	60480	24.8	24.8	174	217	167	316	12.4
44	63360	24.8	24.8	174	223	167	310	6.2
46	66240	24.8	24.8	180	223	161	316	6.2
48	69120	24.8	24.8	180	223	174	323	12.4
50	72000	24.8	24.8	186	223	174	329	12.4
52	74880	24.8	24.8	192	230	167	329	6.2
54	77760	24.8	24.8	192	230	174	335	6.2
56	80640	24.8	24.8	192	230	174	335	12.4
58	83520	24.8	24.8	199	236	167	335	6.2
60	86400	24.8	24.8	199	230	167	335	6.2

Table 5.2.1/2: Percentage biodegradation in Test 1

days	blanc 1	blanc 2	average	test1	BOD (mgO2)	BOD(mgO2/mg test)	% degradation
							NH3
0	0	0	0	0	0.0	0.0	0
2	6.2	0	3.1	6.2	0.6	0.0	1
4	6.2	0	3.1	6.2	0.6	0.0	1
6	6.2	6.2	6.2	31	5.0	0.2	9
8	6.2	6.2	6.2	49.6	8.7	0.4	15
10	12.4	6.2	9.3	62	10.5	0.5	19
12	12.4	6.2	9.3	74.4	13.0	0.6	23
14	12.4	12.4	12.4	86.8	14.9	0.7	26
16	6.2	12.4	9.3	93.1	16.8	0.8	30
18	18.6	18.6	18.6	112	18.7	0.9	33
20	12.4	12.4	12.4	112	19.9	1.0	35
22	18.6	24.8	21.7	130	21.7	1.1	38
24	18.6	24.8	21.7	136	22.9	1.1	41
26	24.8	24.8	24.8	143	23.6	1.2	42
28	18.6	24.8	21.7	149	25.5	1.2	45
30	18.6	24.8	21.7	155	26.7	1.3	47
32	18.6	24.8	21.7	155	26.7	1.3	47
34	24.8	24.8	24.8	161	27.2	1.3	48
36	18.6	24.8	21.7	161	27.9	1.4	49
38	24.8	24.8	24.8	167	28.4	1.4	50
40	24.8	24.8	24.8	174	29.8	1.5	53
42	24.8	24.8	24.8	174	29.8	1.5	53
44	24.8	24.8	24.8	174	29.8	1.5	53
46	24.8	24.8	24.8	180	31.0	1.5	55
48	24.8	24.8	24.8	180	31.0	1.5	55
50	24.8	24.8	24.8	186	32.2	1.6	57
52	24.8	24.8	24.8	192	33.4	1.6	59
54	24.8	24.8	24.8	192	33.4	1.6	59
56	24.8	24.8	24.8	192	33.4	1.6	59
58	24.8	24.8	24.8	199	34.8	1.7	62
60	24.8	24.8	24.8	199	34.8	1.7	62

Table 5.2.1/3: Percentage Biodegradation in Test 2

days	blank 1	blank 2	average	test2	BOD (mgO2)	BOD(mgO2/mg test)	% degradation
							NH3
0	0	0	0	0	0.0	0.0	0
2	6.2	0	3.1	6.2	0.6	0.0	1
4	6.2	0	3.1	6.2	0.6	0.0	1
6	6.2	6.2	6.2	55.8	9.9	0.5	19
8	6.2	6.2	6.2	80.6	14.9	0.8	28
10	12.4	6.2	9.3	99.3	18.0	0.9	34
12	12.4	6.2	9.3	118	21.7	1.1	41
14	12.4	12.4	12.4	130	23.5	1.2	44
16	6.2	12.4	9.3	136	25.3	1.3	47
18	18.6	18.6	18.6	155	27.3	1.4	51
20	12.4	12.4	12.4	155	28.5	1.5	53
22	18.6	24.8	21.7	167	29.1	1.5	54
24	18.6	24.8	21.7	174	30.5	1.6	57
26	24.8	24.8	24.8	186	32.2	1.7	60
28	18.6	24.8	21.7	186	32.9	1.7	61
30	18.6	24.8	21.7	192	34.1	1.7	64
32	18.6	24.8	21.7	199	35.5	1.8	66
34	24.8	24.8	24.8	205	36.0	1.8	67
36	18.6	24.8	21.7	205	36.7	1.9	68
38	24.8	24.8	24.8	217	38.4	2.0	72
40	24.8	24.8	24.8	211	37.2	1.9	69
42	24.8	24.8	24.8	217	38.4	2.0	72
44	24.8	24.8	24.8	223	39.6	2.0	74
46	24.8	24.8	24.8	223	39.6	2.0	74
48	24.8	24.8	24.8	223	39.6	2.0	74
50	24.8	24.8	24.8	223	39.6	2.0	74
52	24.8	24.8	24.8	230	41.0	2.1	77
54	24.8	24.8	24.8	230	41.0	2.1	77
56	24.8	24.8	24.8	230	41.0	2.1	77
58	24.8	24.8	24.8	236	42.2	2.2	79
60	24.8	24.8	24.8	230	41.0	2.1	77

Table 5.2.1/4: Percentage Biodegradation in Reference

days	blank 1	blank 2	average	ref	BOD (mgO2)	BOD(mgO2/mg test)	% degradation
							NH3
0	0	0	0	0	0.0	0.0	0
2	6.2	0	3.1	80.6	15.5	0.8	47
4	6.2	0	3.1	118	23.0	1.1	69
6	6.2	6.2	6.2	130	24.8	1.2	74
8	6.2	6.2	6.2	136	26.0	1.3	78
10	12.4	6.2	9.3	130	24.1	1.2	72
12	12.4	6.2	9.3	136	25.3	1.3	76
14	12.4	12.4	12.4	143	26.1	1.3	78
16	6.2	12.4	9.3	155	29.1	1.5	87
18	18.6	18.6	18.6	149	26.1	1.3	78
20	12.4	12.4	12.4	161	29.7	1.5	89
22	18.6	24.8	21.7	161	27.9	1.4	84
24	18.6	24.8	21.7	167	29.1	1.5	87
26	24.8	24.8	24.8	161	27.2	1.4	82
28	18.6	24.8	21.7	167	29.1	1.5	87
30	18.6	24.8	21.7	161	27.9	1.4	84
32	18.6	24.8	21.7	167	29.1	1.5	87
34	24.8	24.8	24.8	161	27.2	1.4	82
36	18.6	24.8	21.7	167	29.1	1.5	87
38	24.8	24.8	24.8	167	28.4	1.4	85
40	24.8	24.8	24.8	161	27.2	1.4	82
42	24.8	24.8	24.8	167	28.4	1.4	85
44	24.8	24.8	24.8	167	28.4	1.4	85
46	24.8	24.8	24.8	161	27.2	1.4	82
48	24.8	24.8	24.8	174	29.8	1.5	90
50	24.8	24.8	24.8	174	29.8	1.5	90
52	24.8	24.8	24.8	167	28.4	1.4	85
54	24.8	24.8	24.8	174	29.8	1.5	90
56	24.8	24.8	24.8	174	29.8	1.5	90
58	24.8	24.8	24.8	167	28.4	1.4	85
60	24.8	24.8	24.8	167	28.4	1.4	85

Table 5.2.1/5: Percentage Biodegradation in Toxicity

days	blank 1	blank 2	average	toxicity	BOD (mgO2)	BOD(mgO2/mg test)	% degradation
							NH3
0	0	0	0	0	0.0	0.0	0
2	6.2	0	3.1	86.8	16.7	0.8	19
4	6.2	0	3.1	118	23.0	1.1	27
6	6.2	6.2	6.2	136	26.0	1.3	30
8	6.2	6.2	6.2	167	32.2	1.6	37
10	12.4	6.2	9.3	186	35.3	1.8	41
12	12.4	6.2	9.3	205	39.1	2.0	45
14	12.4	12.4	12.4	223	42.1	2.1	49
16	6.2	12.4	9.3	242	46.5	2.3	54
18	18.6	18.6	18.6	242	44.7	2.2	52
20	12.4	12.4	12.4	261	49.7	2.5	58
22	18.6	24.8	21.7	273	50.3	2.5	58
24	18.6	24.8	21.7	279	51.5	2.6	60
26	24.8	24.8	24.8	279	50.8	2.5	59
28	18.6	24.8	21.7	285	52.7	2.6	61
30	18.6	24.8	21.7	292	54.1	2.7	63
32	18.6	24.8	21.7	298	55.3	2.8	64
34	24.8	24.8	24.8	298	54.6	2.7	63
36	18.6	24.8	21.7	304	56.5	2.8	65
38	24.8	24.8	24.8	310	57.0	2.9	66
40	24.8	24.8	24.8	310	57.0	2.9	66
42	24.8	24.8	24.8	316	58.2	2.9	67
44	24.8	24.8	24.8	310	57.0	2.9	66
46	24.8	24.8	24.8	316	58.2	2.9	67
48	24.8	24.8	24.8	323	59.6	3.0	69
50	24.8	24.8	24.8	329	60.8	3.0	70
52	24.8	24.8	24.8	329	60.8	3.0	70
54	24.8	24.8	24.8	335	62.0	3.1	72
56	24.8	24.8	24.8	335	62.0	3.1	72
58	24.8	24.8	24.8	335	62.0	3.1	72
60	24.8	24.8	24.8	335	62.0	3.1	72

Table 5.2.1/6: Percentage Biodegradation in Abiotic Test

	blank 1	blank 2	average	abiotic	BOD (mgO2)	BOD(mgO2/mg test)	% degradation
							NH3
0	0	0	0	0	0.0	0.0	0
2	6.2	0	3.1	0	-0.6	0.0	-1
4	6.2	0	3.1	6.2	0.6	0.0	1
6	6.2	6.2	6.2	6.2	0.0	0.0	0
8	6.2	6.2	6.2	6.2	0.0	0.0	0
10	12.4	6.2	9.3	0	-1.9	-0.1	-3
12	12.4	6.2	9.3	0	-1.9	-0.1	-3
14	12.4	12.4	12.4	6.2	-1.2	-0.1	-2
16	6.2	12.4	9.3	6.2	-0.6	0.0	-1
18	18.6	18.6	18.6	0	-3.7	-0.2	-7
20	12.4	12.4	12.4	6.2	-1.2	-0.1	-2
22	18.6	24.8	21.7	12.4	-1.9	-0.1	-3
24	18.6	24.8	21.7	12.4	-1.9	-0.1	-3
26	24.8	24.8	24.8	6.2	-3.7	-0.2	-7
28	18.6	24.8	21.7	6.2	-3.1	-0.1	-5
30	18.6	24.8	21.7	6.2	-3.1	-0.1	-5
32	18.6	24.8	21.7	6.2	-3.1	-0.1	-5
34	24.8	24.8	24.8	6.2	-3.7	-0.2	-7
36	18.6	24.8	21.7	6.2	-3.1	-0.1	-5
38	24.8	24.8	24.8	6.2	-3.7	-0.2	-7
40	24.8	24.8	24.8	6.2	-3.7	-0.2	-7
42	24.8	24.8	24.8	12.4	-2.5	-0.1	-4
44	24.8	24.8	24.8	6.2	-3.7	-0.2	-7
46	24.8	24.8	24.8	6.2	-3.7	-0.2	-7
48	24.8	24.8	24.8	12.4	-2.5	-0.1	-4
50	24.8	24.8	24.8	12.4	-2.5	-0.1	-4
52	24.8	24.8	24.8	6.2	-3.7	-0.2	-7
54	24.8	24.8	24.8	6.2	-3.7	-0.2	-7
56	24.8	24.8	24.8	12.4	-2.5	-0.1	-4
58	24.8	24.8	24.8	6.2	-3.7	-0.2	-7
60	24.8	24.8	24.8	6.2	-3.7	-0.2	-7

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

inherently biodegradable

Conclusions:

The test material (test1) attained 45% degradation after 28 days.
The test material (test 2) attained 61% degradation after 28 days and didn’t satisfy the 10-day window validation criterion.
Therefore the test material cannot be considered to be readily biodegradable under the strict terms and conditions of OECD Guideline N° 301F.

In the prolonged Manometric Respirometry test, the test material (test1and2) attained respectively 62% and 72% at day 60, demonstrating that the test substance is not persistent. Moreover, the biodegradation percentage reached at day 60 demonstrates that the test material is ultimately (completely) biodegradable according to ECHA (European Chemicals Agency, ECHA guidance chR7b, p179&198, ”Enhanced biodegradation test”).

Executive summary:

The study was performed to assess the ready biodegradability of the test material in an aerobic aqueous media. The method followed that described in the OECD Guideline for testing Chemicals (1992) N°301 F, “Ready Biodegradability; Manometric Respirometry Test”. The test material, at a concentration of 102.5mg/L in test 1, at a concentration of 97.5 mg/L in test 2 was exposed to activated sewage sludge micro-organisms with culture medium in sealed culture vessels in diffused light at 22°C ± 1°C for 60 days.

The test material (test1) attained 45% degradation after 28 days. The test material (test 2) attained 61% degradation after 28 days and didn’t satisfy the 10-day window validation criterion. Therefore the test material cannot be considered to be readily biodegradable under the strict terms and conditions of OECD Guideline N° 301F.

In the prolonged Manometric Respirometry test, the test material (test1and2) attained respectively 62% and 72%at day 60, demonstrating that the test substance is not persistent. Moreover, the biodegradation percentage reached at day 60 demonstrates that the test material is ultimately (completely) biodegradable according toECHA (European Chemicals Agency, ECHA guidance chR7b, p179&198, ”Enhanced biodegradation test”).