Bis(2,3-epoxypropyl) cyclohex-4-ene-1,2-dicarboxylate

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:

key study

Study period:

2012-01-12 to 2012-03-13

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: EU, OECD method, GLP

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

Species/Origin: Aerobic activated sludge, micro organisms from a domestic waste water treatment plant was supplied by the sewage plant Rossdorf, Germany.
Conditioning: The aerobic 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 done three times. The sediment was re-suspended in test water and aerated overnight. 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. This suspension was used for the experiment.

Duration of test (contact time):

60 d

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

The purpose of this study was to determine the ready biodegradability of the test item bis(2,3-epoxypropyl) cyclohexane-1,2-dicarboxylate. The test item was exposed to aerobic activated sludge from the aeration tank of a domestic waste water treatment plant for 60 days. The biodegradation was followed by the oxygen uptake of the micro organisms 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.
This type of study is recognized by the international test guidelines and should provide a rational basis to assess the ready biodegradation properties of the test item when incubated with aerobic activated sludge.
The test flasks prepared according paragraph 6.6 were incubated at 22 * 1 °C. The pressure decrease in the reaction vessels was measured over complete experimental phase of 60 days using the BSB Sensomat system, Aqualytic Dortmund. The test flasks were closed gas-tight by a measuring head. Potassium hydroxide solution (45%) was used for trapping the produced carbon dioxide. The amount of O2 consumed by the activated sludge was calculated from the decrease of pressure in the reaction vessel.
Preparation of Test Flasks: The amounts of test item were dissolved in acetone and dropped onto 100 mg silica gel. After evaporation of the solvent (for about 24 hours) the treated silica gel (230 – 400 mesh) was directly dosed into the flasks (ISO 10634; Handley et al., 2002). The inoculum control contained untreated silica gel with 100 µl acetone, which was evaporated overnight.
The reference item was directly weighed into the test flasks.
Incubation: The closed test flasks were incubated in a climatised room 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.
Test Duration: 60 days
Measurement of Oxygen: 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.
Temperature: Temperature was measured each working day in the climatised room.
pH-Value: pH-values were measured in control, procedure control and a separately prepared test flask with test item at test start (to prevent loss of test item in the test flasks) and in all flasks at the end of the test using a pH-electrode WTW pH 340i.

Reference substance:

benzoic acid, sodium salt

Parameter:

% degradation (O2 consumption)

Value:

94

Sampling time:

60 d

Details on results:

Biodegradation of Test Item
Percentage Biodegradation: ThODNH4
The mean percentage biodegradation at the end of the 28-day exposure period was 53% (ThODNH4). The 10-day window was not passed. The incubation period was prolonged up to 60 days.
Conclusion: The biodegradation of bis(2,3-epoxypropyl) cyclohexane-1,2-dicarboxylate was 94% after 60 days of incubation.
Whilst the test item cannot be considered to be readily biodegradable under the strict terms and conditions of OECD Guideline No. 301F, the evidence of aerobic degradation (94%) that did not plateau before the end of the 60-day indicate the potential for complete mineralisation in the environment. Therefore, bis(2,3-epoxypropyl)cyclohexane-1,2-dicarboxylate can be considered to be inherently biodegradable.

Parameter:

COD

Value:

1.3 mg O2/g test mat.

Results with reference substance:

Biodegradation of Reference Item Sodium Benzoate
Percentage Biodegradation: The reference item sodium benzoate was sufficiently degraded to 84% after 14 days and to 93% after 28 days of incubation. The results are represented in Tables 2 and 3 and Figure 1.
Conclusion: The percentage biodegradation of the reference item con-firms the suitability of the used aerobic activated sludge inoculum.

Table.Percentage Biodegradation of Test Item, of Sodium Benzoate and of the Toxicity Control based on ThOD_NH4

Time	Percentage Biodegradation^1
(Days)	bis(2,3-epoxypropyl) cyclohexane-1,2-dicarboxylate^1		Sodium Benzoate^2	Toxicity control^1, 2
	Flask 1 [%]	Flask 2 [%]	Flask 5 [%]	Flask 7 [%]
1	0	0	35	20
2	0	-4	44	26
3	-2	-2	63	39
4	-4	-4	64	41
5	-4	-4	70	43
6	0	-4	73	46
7	-2	-2	77	45
8	2	2	77	48
9	4	8	78	51
10	8	8	81	53
11	15	11	81	54
12	17	17	83	57
13	15	19	81	57
14	19	23	84	59
15	23	23	84	59
16	21	24	83	60
17	23	23	84	61
18	26	26	84	62
19	30	26	84	64
20	30	30	84	64
21	34	34	87	66
22	38	34	87	67
23	38	38	90	69
24	41	41	90	69
25	43	43	92	68
26	49	45	90	67
27	53	49	93	69
28	56	49	93	69

29	56	53	93	69
30	62	54	92	70
31	64	56	93	71
32	68	56	93	71
33	66	58	94	70
34	68	60	93	69
35	71	64	93	69
36	71	68	93	69
37	75	71	93	69
38	75	71	93	69
39	75	75	93	69
40	75	75	93	69
41	75	75	93	69
42	75	79	93	69
43	79	79	93	69
44	79	79	93	69
45	79	83	93	69
46	83	83	93	69
47	83	83	93	69
48	86	86	93	69
49	86	86	93	69
50	86	86	93	69
51	86	86	93	69
52	86	90	93	69
53	86	90	93	69
54	90	90	93	69
55	90	94	93	69
56	90	94	93	69
57	90	94	93	69
58	94	94	93	69
59	94	94	93	69
60	94	94	93	69

            ¹ThOD_NH4of bis(2,3-epoxypropyl) cyclohexane-1,2-dicarboxylate: 1.30 mg O₂/mg test item
            ²ThOD_NH4of sodium benzoate: 1.666 mg O₂/mg reference item

 

Validity criteria fulfilled:

yes

Interpretation of results:

inherently biodegradable

Conclusions:

The biodegradation of bis(2,3-epoxypropyl) cyclohexane-1,2-dicarboxylate was 94% after 60 days of incubation.
Whilst the test item cannot be considered to be readily biodegradable under the strict terms and conditions of OECD Guideline No. 301F, the evidence of aerobic degradation (94%) that did not plateau before the end of the 60-day indicate the potential for complete mineralisation in the environment. Therefore, bis(2,3-epoxypropyl)cyclohexane-1,2-dicarboxylate can be considered to be inherently biodegradable.

Executive summary:

The ready biodegradability of the test item in a manometric respirometry test was determided based on the proceduresindicated by the following internationally accepted methods:

- EU method C.4 -D

- OECD method 301 F

The test item was investigated for its ready biodegradability in a manometric respirometry test over a period of 60 days. The biodegradation was followed by the oxygen uptake of the micro-organisms 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.

For the test item the evaluation of biodegradation has to be based on COD determination.

The criterion for ready biodegradability under the conditions of a manometric respirometry test is the 10-day window, describing the period between reaching at least 10% degradation and 60% degradation. This period should not exceed 10 days. The 10-day window criterion was not passed, because bis(2,3-epoxypropyl) cyclohexane-1,2-dicarboxylate was degraded to 53% after 28 days.

The mean biodegradation after 60 days of bis(2,3-epoxypropyl) cyclohexane-1,2-dicarboxylate was 94% (ThOD_NH4).

Whilst the test item cannot be considered to be readily biodegradable under the strict terms and conditions of OECD Guideline No. 301F, the evidence of aerobic degradation (94%) that did not plateau before the end of the 60-day indicate the potential for complete mineralisation in the environment. Therefore, bis(2,3-epoxypropyl)cyclohexane-1,2-dicarboxylate can be considered to be inherently biodegradable.

The reference item sodium benzoate was sufficiently degraded to 84% after 14 days and to 93% after 28 days of incubation, thus confirming the suitability of theaerobic activatedsludge inoculum used.

In the toxicity control containing both, the test item and the reference item sodium benzoate, 59% biodegradation was noted within 14 days and 69% biodegradation after 28 days of incubation. Thus, the test item can be assumed to be not inhibitory to theaerobic activatedsludge micro organisms.

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

2012-01-12 to 2012-03-13

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: EU, OECD method, GLP

Justification for type of information:

Please refer to the Read-across justification document enclosed in chapter 13 for more details.

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

Species/Origin: Aerobic activated sludge, micro organisms from a domestic waste water treatment plant was supplied by the sewage plant Rossdorf, Germany.
Conditioning: The aerobic 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 done three times. The sediment was re-suspended in test water and aerated overnight. 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. This suspension was used for the experiment.

Duration of test (contact time):

60 d

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

The purpose of this study was to determine the ready biodegradability of the test item bis(2,3-epoxypropyl) cyclohexane-1,2-dicarboxylate. The test item was exposed to aerobic activated sludge from the aeration tank of a domestic waste water treatment plant for 60 days. The biodegradation was followed by the oxygen uptake of the micro organisms 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.
This type of study is recognized by the international test guidelines and should provide a rational basis to assess the ready biodegradation properties of the test item when incubated with aerobic activated sludge.
The test flasks prepared according paragraph 6.6 were incubated at 22 * 1 °C. The pressure decrease in the reaction vessels was measured over complete experimental phase of 60 days using the BSB Sensomat system, Aqualytic Dortmund. The test flasks were closed gas-tight by a measuring head. Potassium hydroxide solution (45%) was used for trapping the produced carbon dioxide. The amount of O2 consumed by the activated sludge was calculated from the decrease of pressure in the reaction vessel.
Preparation of Test Flasks: The amounts of test item were dissolved in acetone and dropped onto 100 mg silica gel. After evaporation of the solvent (for about 24 hours) the treated silica gel (230 – 400 mesh) was directly dosed into the flasks (ISO 10634; Handley et al., 2002). The inoculum control contained untreated silica gel with 100 µl acetone, which was evaporated overnight.
The reference item was directly weighed into the test flasks.
Incubation: The closed test flasks were incubated in a climatised room 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.
Test Duration: 60 days
Measurement of Oxygen: 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.
Temperature: Temperature was measured each working day in the climatised room.
pH-Value: pH-values were measured in control, procedure control and a separately prepared test flask with test item at test start (to prevent loss of test item in the test flasks) and in all flasks at the end of the test using a pH-electrode WTW pH 340i.

Reference substance:

benzoic acid, sodium salt

Parameter:

% degradation (O2 consumption)

Value:

94

Sampling time:

60 d

Details on results:

Biodegradation of Test Item
Percentage Biodegradation: ThODNH4
The mean percentage biodegradation at the end of the 28-day exposure period was 53% (ThODNH4). The 10-day window was not passed. The incubation period was prolonged up to 60 days.
Conclusion: The biodegradation of bis(2,3-epoxypropyl) cyclohexane-1,2-dicarboxylate was 94% after 60 days of incubation.
Whilst the test item cannot be considered to be readily biodegradable under the strict terms and conditions of OECD Guideline No. 301F, the evidence of aerobic degradation (94%) that did not plateau before the end of the 60-day indicate the potential for complete mineralisation in the environment. Therefore, bis(2,3-epoxypropyl)cyclohexane-1,2-dicarboxylate can be considered to be inherently biodegradable.

Parameter:

COD

Value:

1.3 mg O2/g test mat.

Results with reference substance:

Biodegradation of Reference Item Sodium Benzoate
Percentage Biodegradation: The reference item sodium benzoate was sufficiently degraded to 84% after 14 days and to 93% after 28 days of incubation. The results are represented in Tables 2 and 3 and Figure 1.
Conclusion: The percentage biodegradation of the reference item con-firms the suitability of the used aerobic activated sludge inoculum.

Table.Percentage Biodegradation of Test Item, of Sodium Benzoate and of the Toxicity Control based on ThOD_NH4

Time	Percentage Biodegradation^1
(Days)	bis(2,3-epoxypropyl) cyclohexane-1,2-dicarboxylate^1		Sodium Benzoate^2	Toxicity control^1, 2
	Flask 1 [%]	Flask 2 [%]	Flask 5 [%]	Flask 7 [%]
1	0	0	35	20
2	0	-4	44	26
3	-2	-2	63	39
4	-4	-4	64	41
5	-4	-4	70	43
6	0	-4	73	46
7	-2	-2	77	45
8	2	2	77	48
9	4	8	78	51
10	8	8	81	53
11	15	11	81	54
12	17	17	83	57
13	15	19	81	57
14	19	23	84	59
15	23	23	84	59
16	21	24	83	60
17	23	23	84	61
18	26	26	84	62
19	30	26	84	64
20	30	30	84	64
21	34	34	87	66
22	38	34	87	67
23	38	38	90	69
24	41	41	90	69
25	43	43	92	68
26	49	45	90	67
27	53	49	93	69
28	56	49	93	69

29	56	53	93	69
30	62	54	92	70
31	64	56	93	71
32	68	56	93	71
33	66	58	94	70
34	68	60	93	69
35	71	64	93	69
36	71	68	93	69
37	75	71	93	69
38	75	71	93	69
39	75	75	93	69
40	75	75	93	69
41	75	75	93	69
42	75	79	93	69
43	79	79	93	69
44	79	79	93	69
45	79	83	93	69
46	83	83	93	69
47	83	83	93	69
48	86	86	93	69
49	86	86	93	69
50	86	86	93	69
51	86	86	93	69
52	86	90	93	69
53	86	90	93	69
54	90	90	93	69
55	90	94	93	69
56	90	94	93	69
57	90	94	93	69
58	94	94	93	69
59	94	94	93	69
60	94	94	93	69

            ¹ThOD_NH4of bis(2,3-epoxypropyl) cyclohexane-1,2-dicarboxylate: 1.30 mg O₂/mg test item
            ²ThOD_NH4of sodium benzoate: 1.666 mg O₂/mg reference item

 

Validity criteria fulfilled:

yes

Interpretation of results:

inherently biodegradable

Conclusions:

The biodegradation of bis(2,3-epoxypropyl) cyclohexane-1,2-dicarboxylate was 94% after 60 days of incubation.
Whilst the test item cannot be considered to be readily biodegradable under the strict terms and conditions of OECD Guideline No. 301F, the evidence of aerobic degradation (94%) that did not plateau before the end of the 60-day indicate the potential for complete mineralisation in the environment. Therefore, bis(2,3-epoxypropyl)cyclohexane-1,2-dicarboxylate can be considered to be inherently biodegradable.

Executive summary:

The ready biodegradability of the test item in a manometric respirometry test was determided based on the proceduresindicated by the following internationally accepted methods:

- EU method C.4 -D

- OECD method 301 F

The test item was investigated for its ready biodegradability in a manometric respirometry test over a period of 60 days. The biodegradation was followed by the oxygen uptake of the micro-organisms 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.

For the test item the evaluation of biodegradation has to be based on COD determination.

The criterion for ready biodegradability under the conditions of a manometric respirometry test is the 10-day window, describing the period between reaching at least 10% degradation and 60% degradation. This period should not exceed 10 days. The 10-day window criterion was not passed, because bis(2,3-epoxypropyl) cyclohexane-1,2-dicarboxylate was degraded to 53% after 28 days.

The mean biodegradation after 60 days of bis(2,3-epoxypropyl) cyclohexane-1,2-dicarboxylate was 94% (ThOD_NH4).

Whilst the test item cannot be considered to be readily biodegradable under the strict terms and conditions of OECD Guideline No. 301F, the evidence of aerobic degradation (94%) that did not plateau before the end of the 60-day indicate the potential for complete mineralisation in the environment. Therefore, bis(2,3-epoxypropyl)cyclohexane-1,2-dicarboxylate can be considered to be inherently biodegradable.

The reference item sodium benzoate was sufficiently degraded to 84% after 14 days and to 93% after 28 days of incubation, thus confirming the suitability of theaerobic activatedsludge inoculum used.

In the toxicity control containing both, the test item and the reference item sodium benzoate, 59% biodegradation was noted within 14 days and 69% biodegradation after 28 days of incubation. Thus, the test item can be assumed to be not inhibitory to theaerobic activatedsludge micro organisms.

Description of key information

Ready Biodegradability of bis(2,3-epoxypropyl)cyclohexane-1,2-dicarboxylate in a Manometric Respirometry Test.

This data is coming from a read across: 1,3-Isobenzofurandione, hexahydro-, reaction products with epichlorohydrin (SOURCE) to bis(2-3-epoxypropyl)cyclohex-4-ene-1-2-dicarboxylate (TARGET)

Key value for chemical safety assessment

Biodegradation in water:

inherently biodegradable

Additional information

In this study, the ready biodegradability was tested in a Manometric Respirometry Test. The criterion for ready biodegradability under the conditions of a manometric respirometry test is the 10-day window, describing the period between reaching at least 10% degradation and 60% degradation. This period should not exceed 10 days.

The mean biodegradation after 28 days of bis(2,3 -epoxypropyl)cyclohexane-1,2 -dicarboxylate was 53% (ThOD_NH4) and 94% after 60 days; the 10 day window criterion was not passed.

Whilst bis(2,3 -epoxypropyl)cyclohexane-1,2 -dicarboxylate cannot be considered to be readily biodegradable under the strict terms and conditions of OECD Guideline No. 301F, the evidence of aerobic degradation (94%) that did not plateau before the end of the 60-day indicate the potential for complete mineralisation in the environment.