4,8-Cyclododecadien-1-one

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:

21-10-2014 to 06-02-2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study performed under GLP. All relevant validity criteria were met and no significant deviations.

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

Test temperature deviated from specified: 22 ±1 °C (Actual 22.1 – 23.4 °C). This is not a significant deviation as the temperature remained within the guideline limits: 22 ± 2 °C.

Qualifier:

according to guideline

Guideline:

other: GB/T 2180 I - 2008: Chemicals - Ready Biodegradability: Manometric Respirometry Test. Standards Press of China (2008).

Deviations:

yes

Remarks:

see above.

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 (e.g. location, sampling depth, contamination history, procedure): Activated sludge from Liede Sewage Treatment Plant of Guangzhou, China. The inoculum was selected as it was recommended by "The Guidelines for the Testing of Chemicals". The batch number of the inoculum is included in the full study report.
- Storage conditions: See pretreatment field.
- Storage length: < 1 week; 3 days from sampling to test initiation.
- Preparation of inoculum for exposure:
- Pretreatment: The sludge was removed any coarse particles and impurities on the surface, then was washed with the test medium (1100 g, 10 min, repeated for 6 times), the supernatant liquid phase was decanted and the suspended solids re-suspended in the test medium. The dry weight of the suspended solid was determined as 6.4 g/L. Before the test, 62.5 mL of the above inoculum was taken into a triangular flask and suspended in 37.5 mL of the test medium to obtain a concentration equivalent to 4.0 g suspended solids per litre, keeping the sludge aerobic until used. The inoculum was added into the test suspensions and the procedure control to give a final concentration of 28 mg suspended solids per litre and those of the inoculum blanks and the toxicity control to give a final concentration of 28 mg suspended solids per litre.
- Concentration of sludge: The sludge was diluted in flasks to 28 mg SS/L. within the test systems; 28 mg SS/L in the negative and toxicity controls.

Duration of test (contact time):

28 d

Initial conc.:

18 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: See table 1. Solution A [KH2PO4: 8.50 g; K2HPO4.3H2O: 28.50 g; Na2HPO4.12H2O: 67.15 g; NH4Cl: 0.50 g - in 1 L water]; Solution B [CaCl2: 13.75 g in 0.5 L water]; Solution C [MgSO4.7H2O: 11.25 g in 0.5 L water]; Solution D [FeCl3,6H2O: 0.125 g in 0.5 L water]. 80 mL of solution A was mixed with 6 L deionised water; then 5 ml of solutions B, C and D and made up to 8 L with deionised water.
- Solubilising agent (type and concentration if used): None.
- Test temperature: 22 ±1 °C (Actual 22.1 – 23.4 °C – not a significant deviation as remained within OECD TG 301F guideline limits)
- pH: See table 1.
- pH adjusted: If necessary adjusted the pH values of bottles 1, 2, 3, 4, 5 and 6 to 7.4 ± 0.2 at the start of the test
- Aeration of dilution water: Not reported
- Continuous darkness: Yes.

TEST SYSTEM
- Culturing apparatus: Flasks with continuous stirring.
- Number of culture flasks/concentration: In duplicate (Inoculum blank); single flasks (procedure control and toxicity control)
- Method used to create aerobic conditions: Sealed flasks with sensor head/CO2 trap.
- Measuring equipment: The respirometer used during this study is an Oxitop Control System.

SAMPLING
- Sampling frequency: Daily.
- Sampling method: Respirometry measuring the oxygen uptake of the test medium.

CONTROL AND BLANK SYSTEM
- Inoculum blank: Yes. See table 1.
- Abiotic sterile control: No.
- Toxicity control: Yes.
- Other: Positive reference control ('Procedure control' ; Sodium Benzoate).

Reference substance:

benzoic acid, sodium salt

Remarks:

33 mg/L

Test performance:

(1) The oxygen uptake of the inoculum blanks were 9.8 mg/L and 9.5 mg/L, the mean was 9.7 mg/L, less than 60 mg/L in 28d.
(2) At the end of the test, the pH values of each test vessel were 7.59-7.78, within the range of 6.0-8.5.
(3) The difference of extremes of replicate values of the removal of the test substance at the plateau, at end of the test or at the end of the 10-d window (where applicable) was less than 20% (actual day-28: 71.6% and 70.5%).
(4) The percentage degradation of the procedure control and the toxicity control were 86.0% and 63.0%, which had reached the pass levels of 60% and 25% of ThOD on 14d.

Parameter:

% degradation (O2 consumption)

Value:

71.1

Sampling time:

28 d

Remarks on result:

other: n=2; 10-d window not met

Results with reference substance:

Degradation of sodium benzoate exceeded 86.0 % after 14 days: the activity of the inoculum was thus verified (validity criterion).

Table 1. Degradation Results for test item, procedure and toxicity controls

Sample		Sample time (day)
0	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28
Toxicity control:
BOD (mg/L)		5.6	39.5	42.3	45.1	49.3	56.4	53.5	56.4	60.6	59.2	63.4	66.2	70.5	76.1	74.7	76.1	81.7	78.9	83.1	81.7	86.0	87.4	87.4	86.0	87.4	88.8	88.8	91.6
% biodegradation		2.8	33.4	35.5	37.1	40.6	46.7	42.9	45.8	49.4	47.8	51.5	54.0	58.0	63.0	61.4	62.6	67.9	65.0	69.1	67.7	71.7	73.0	72.8	71.6	73.3	74.0	74.0	76.6
Test suspension
BOD (mg/L) replicate 1		4.5	6.2	6.8	8.5	8.5	9.6	13.6	21.5	27.1	30.5	32.8	34.5	35.0	36.7	37.9	39.0	40.1	41.3	41.3	42.4	43.0	43.5	44.7	44.7	44.1	45.2	46.3	46.9
BOD (mg/L) replicate 2		4.5	5.7	6.8	8.5	8.5	9.6	15.8	22.0	27.7	30.5	32.8	34.5	35.0	37.3	37.9	39.0	39.6	40.7	40.7	41.3	42.4	43.0	44.1	44.1	44.1	45.2	46.3	46.3
% biodeg replicate 1		3.6	4.7	4.7	5.9	5.0	6.1	11.5	27.0	27.2	43.3	47.2	50.2	51.2	53.8	55.6	57.4	59.8	61.4	61.8	63.6	64.8	65.8	67.7	67.9	67.5	68.4	70.5	71.6
% biodeg replicate 2		3.6	3.8	4.7	5.9	5.0	6.1	15.8	28.0	38.4	43.3	47.2	50.2	51.2	55.0	55.6	57.4	58.8	60.2	60.7	61.5	63.6	64.8	66.5	66.7	67.5	68.4	70.5	70.5
Average % biodeg		3.6	4.2	4.7	5.9	5.0	6.1	13.6	27.5	37.8	43.3	47.2	50.2	21.2	54.4	55.6	57.4	59.3	60.8	61.2	62.6	64.2	65.3	67.1	67.3	67.5	68.4	70.5	71.1
Inoculum blank
BOD (mg/L) replicate 1		2.8	3.9	4.5	5.6	6.2	6.7	7.9	7.6	7.9	8.1	8.4	8.4	8.4	8.7	9.0	9.0	9.0	9.3	9.3	9.3	9.3	9.3	9.5	9.5	9.0	9.8	9.8	9.8
BOD (mg/L) replicate 2		2.5	3.6	4.2	5.3	5.6	6.2	7.3	7.3	7.6	7.9	8.1	8.4	8.4	8.7	9.0	9.3	9.0	9.5	9.0	9.3	9.3	9.3	9.5	9.3	9.0	9.5	9.5	9.5
Average BOD (mg/L)		2.7	3.8	4.4	5.5	5.9	6.5	7.6	7.5	7.8	8.0	8.3	8.4	8.4	8.7	9.0	9.2	9.0	9.4	9.2	9.3	9.3	9.3	9.5	9.4	9.0	9.7	9.7	9.7
Procedure control
BOD (mg/L)		3.4	35.6	38.4	43.0	45.8	49.7	50.3	51.4	53.1	53.1	54.3	53.7	55.4	56.0	56.0	56.0	57.7	56.5	57.7	58.4	58.2	58.2	58.2	58.2	57.7	58.2	58.2	58.8
% biodegradation		1.4	57.9	61.9	68.3	72.6	78.6	77.6	79.9	82.4	82.0	83.7	82.4	85.4	86.0	85.4	85.2	88.6	85.6	88.3	89.3	88.9	88.9	88.6	88.7	88.6	88.3	88.3	89.4

14d of the test, the percentage degradation of the procedure control and the toxicity control were 86.0% and 63.0% respectively, which showed that the inoculum activity could meet the requirement of the test, and the test substance was considered not to have a inhibitory effect on the sewage sludge micro-organisms used in the study.

28d, the percentage biodegradation of the test substance were 71.6% and 70.5%, the mean biodegradation was 71.1%.

 

The difference of extremes of replicate values of the removal of the test substance at the end of the test (the percentage degradation were 67.81% and 64.60%) was less than 20 %.

The percentage biodegradation of the reference sodium benzoate at day 14 was 86.0%, greater than 60%.

The percentage biodegradation in Toxicity control at day 14 was 63.0%, greater than 25%.

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

The test item mean biodegradation in duplicate was 71.1 % at day 28 (10-day window does not apply, OECD 2006).

Executive summary:

The ready biodegradability test was carried out according to OECD TG 301F and China Guidelines for the Testing of Chemicals, Effects on Degradation and Accumulation, Version 2, 301F Manometric Respirometry Test (2013) under GLP. The test substance, at a concentration of 18 mg/L was exposed to activated sewage sludge micro-organisms obtained from the Liede Sewage Treatment Plant of Guangzhou, China, with culture medium in sealed culture vessels in the dark at 22°C ± 2°C for 28 days. The sludge was diluted in flasks to 28 mg SS/L. within the test systems; 28 mg SS/L in the negative and toxicity controls. The degradation of the test substance was assessed by the measurement of daily oxygen consumption on days 0 and 28 using an Oxitop control system. Control solutions with inoculum and the reference substance, sodium benzoate, together with a toxicity control were used for validation purposes. The oxygen uptake of the inoculum blanks were 9.8 mg/L and 9.5 mg/L, the mean was 9.7 mg/L, less than 60 mg/L in 28d. At the end of the test, the pH values of each test vessel were within the range of 6.0-8.5. The test system therefore met the validation criteria of the guideline. The toxicity test attained 60 % degradation after 28 days thereby confirming that the test substance was not inhibitory to the sewage treatment micro-organisms used in the study. Sodium Benzoate attained 86.0 % degradation after 28 days thereby confirming the suitability of the inoculum and test conditions. The mean biodegradation for duplicate test flasks at 28 days for the test item was 71.1 % (the 10-day window was not met). The 10-day window that can be applied to Manometric Respiratory Tests, where 60% biodegradation must be achieved following the attainment of 10 % biodegradation, is not applied to multi-constituent substances consisting of structurally similar constituents (OECD, 2006). Under the conditions of the study, test item is considered as readily biodegradable.

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

09-09-2014 to 08-12-2014

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study performed under GLP. All relevant validity criteria were met.

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))

Deviations:

no

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): Activated sludge from Test inoculum was purchased from the Chemicals Evaluation and Research Institute (3-2-7 Miyanojin, Kurume, Fukuoka 839-0801, Japan), on August 20, 2014. Full details of the inoculum is included in the full study report.
- Storage conditions: Not reported.
- Storage length: 4 weeks from inoculum acquisition to test initiation.
- Concentration of sludge: 30 mg/L (final concentration under test conditions).

Duration of test (contact time):

28 d

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Remarks:

using oxygen consumption analyser in a closed system

Parameter followed for biodegradation estimation:

DOC removal

Remarks:

by organic carbon analyser

Parameter followed for biodegradation estimation:

test mat. analysis

Remarks:

by direct quantitative analysis by GC-FID and GC-MS

Details on study design:

TEST CONDITIONS
- Composition of medium: Mineral medium was prepared by adding each 6 mL of stock solution A, B, C and D (as specified in JIS K 0102-2008 21) to 1976 mL of purified water (which was adapted to quality of Japanese pharmacopeia) and adjusted the pH to 7.0. Test bottles were then set as listed in table 1.
- Solubilising agent (type and concentration if used): None.
- Test temperature: 25 ± 1 °C
- pH: Test suspension bottle 1: 7.04; test suspension bottle 2: 7.03; test suspension bottle 3: 7.04; toxicity control: 7.00; Inoculum blank: 7.00; Abiotic control: 5.79.
- pH adjusted: Yes, the pH values of bottles the test suspension, toxicity control, abiotic control and inoculum blank were 7.0 ± 0.1 at the start of the test
- Aeration of dilution water: Not reported
- Continuous darkness: Yes.

TEST SYSTEM
- Culturing apparatus: Culture bottles with continuous stirring.
- Number of culture flasks/concentration: Triplicate (test item suspensions); single flasks (Inoculum blank, abiotic control and toxicity control)
- Method used to create aerobic conditions: Sealed flasks with Coulometer sensor head; evolved CO2 was trapped in soda lime bottles.
- Measuring equipment: Oxygen consumption was measured continuously using an OM-3100A Coulometer.
- Other: Dissolved organic carbon was measured by TOC-L DOC analysis at day 28 (except for activity control group).

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

Reference substance:

aniline

Test performance:

Applicant assessment indicates:
(1) The oxygen uptake of the inoculum blanks were 5.6 mg/L, less than 60 mg/L in 28d.
(2) At the end of the test, the pH values of each test vessel were 6.90-6.96, within the range of 6.0-8.5.
(3) The difference of extremes of replicate values of the removal of the test substance at the plateau, at end of the test or at the end of the 10-d window (where applicable) was less than 20% (actual day-28: 81%, 86% and 84%).
(4) The percentage degradation of the procedure control (aniline) was day 7: 71.7% and day 14: 74%
(5) There was no significant degradation in the inoculum blank or abiotic control during the study.

Parameter:

% degradation (O2 consumption)

Value:

83.6

Sampling time:

28 d

Parameter:

% degradation (test mat. analysis)

Remarks:

GC analysis

Value:

100

Sampling time:

28 d

Parameter:

% degradation (DOC removal)

Value:

100

Sampling time:

28 d

Results with reference substance:

The reference substance (aniline) attained 70% biodegradation after 7 days and 74% biodegradation after 14 days, based on oxygen consumption. Degradation activity of the sludge was normal and the test was valid.

Table 1. Biodegradability calculated from oxygen consumption

Bottle No.	Groups	Theoretical oxygen demand (mg)	7^thday		14^thday		21^stday		28^thday
			Measured value (mg)	Degradability (%)	Measured value (mg)	Degradability (%)	Measured value (mg)	Degradability (%)	Measured value (mg)	Degradability (%)
1	Test suspensions bottle 1	86.2	9.4	8	46.7	49	65.1	69	75.8	81
2	Test suspensions bottle 2	86.2	6.5	4	49.4	52	71.0	76	79.7	86
3	Test suspensions bottle 3	86.2	3.2	1	45.4	47	64.6	69	77.6	84
Mean degradability of test suspensions on the 28^thday										84
4	Activity control (Aniline)	90.6	66.5	70	71.7	74	73.0	75	74.0	75
5	Inoculum blank	-	2.7	-	4.7	-	5.5	-	5.6	-
6	Abiotic control	-	0.0	-	0.0	-	0.0	-	0.0	-

Table 2. Biodegradability calculated from the direct quantitative analysis by the GC method

Culture bottle No.	Item		Degradability (%)
1	Test suspensions bottle 1	Peak 1	100
		Peak 2	100
		Peak 3	100
		Test substance	100
2	Test suspensions bottle 2	Peak 1	100
		Peak 2	100
		Peak 3	100
		Test substance	100
3	Test suspensions bottle 3	Peak 1	100
		Peak 2	100
		Peak 3	100
		Test substance	100

Table 3. Result of the measurement of the dissolved organic carbon concentration

Culture bottle No.	Item	Amount supplied (experimental value)(mg)	Carbon measured	Peak area				Concentration of carbon calculated from calibration (mgL^-1)	Concentration of carbon calculated from calibration (TC-IC) (mgL^-1)	Amount of dissolved organic carbon^2)DOC (mg)	Ratio of DOC relative to dissolved organic carbon content calculated from the amount supplied (%)
		Dissolved organic carbon content calculated from the amount supplied^1)(calculated value)(mg)		Measured value			Mean value
1	Test suspension bottle 1	30.00	TC	11.61	11.45	11.59	11.55	2.772	1.936	0.58 (0.14)^3)	1
		24.24	IC	3.919	3.948	3.893	3.920	0.8361
2	Test suspension bottle 2	30.00	TC	12.28	12.03	12.00	12.10	2.899	1.523	0.45 (0.01)^3)	0
		24.24	IC	6.339	6.213	6.333	6.295	1.386
3	Test suspension bottle 3	30.00	TC	10.58	10.71	10.52	10.60	2.555	1.831	0.55 (0.11)^3)	0
		24.24	IC	3.410	3.413	3.485	3.436	0.7241
5	Inoculum blank	-	TC	8.996	9.725	9.200	9.307	2.258	1.465	0.44	-
		-	IC	3.728	3.649	3.821	3.733	0.7927
6	Abiotic control	30.00	TC	355.8	352.9	349.7	352.8	81.00	80.80	24.24	100
		24.24	IC	1.135	1.201	1.183	1.173	0.2003

1)Dissolved organic carbon content calculated from the amount supplied (mg)= Amount supplied of the test substance (mg) x TOC [C-mg/mg]                              

(TOC=12x12/178.28=0.808 [C-mg/mg])

2)Amount of dissolved organic carbon (mg) = [concentration of carbon calculated from calibration (mgL^-1)] x (300/1000)

3)The number in parentheses is the value given by subtracting the amount of dissolved organic carbon in the inoculum blank.

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

The test item mean biodegradation in triplicate was 83.6 % at day 28 (10 or 14-day window does not apply to OECD TG 301C).

Executive summary:

The ready biodegradability test was carried out according to OECD TG 301C MITI Test (I) under GLP. The test item, at a concentration of 100 mg/L was exposed to activated sewage sludge micro-organisms obtained from Chemicals Evaluation and Research Institute, Japan with culture medium in sealed culture vessels in the dark at 25°C ± 1°C for 28 days. The sludge was diluted in flasks to 30 mg SS/L. within the test systems; 30 mg SS/L in the negative and reference item controls. The degradation of the test substance was assessed by the measurement of daily oxygen consumption on days 0 and 28 using an OM-3100A Coulometer. Inoculum blank control and control solutions with inoculum and the reference substance: aniline, together with a abiotic control were used for validation purposes. The oxygen uptake of the inoculum blanks were 5.6 mg/L, less than 60 mg/L in 28d. At the end of the test, the pH values of each test vessel were within the range of 6.0-8.5. The test system therefore met the validation criteria of the guideline. The activity procedure control test using aniline attained 74% degradation after 28 days confirming the suitability of the inoculum and test conditions. The mean biodegradation for triplicate test flasks at 28 days for the test item was 83.6 % calculated by oxygen consumption. The biodegradability calculated from the concentration of dissolved organic carbon was 100% (mean) in the test suspensions. There was evidence of test item degradation and mineralisation of degradation products determined within the study. The test item was biodegraded by mean (n=3): 83.6% at day 28 in the OECD 301C MITI Test (I). The 10 or 14-day window does not apply within the OECD TG 301C MITI Test (I) or to test items consisting of homologous multi-constituent substances consisting of structurally similar constituents (OECD, 2006). Under the conditions of the study, test item is considered as readily biodegradable.

 

Description of key information

Biodegradation: readily biodegradable, mean biodegradation 71.1% (28-days, 10-day window not met). 10-day window not applicable to multi-constituent substances consisting of structurally similar constituents (OECD, 2006), OECD TG 301F, 2015

Biodegradation: readily biodegradable, mean biodegradation 83.6% (28-days, 10- or 14- day window does not apply). 10- or 14- day window not applicable to test guideline, OECD TG 301C MITI Test (I), 2014

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Type of water:

freshwater

Additional information

OECD 301F, 2015: The ready biodegradability test was carried out according to OECD TG 301F and China Guidelines for the Testing of Chemicals, Effects on Degradation and Accumulation, Version 2, 301F Manometric Respirometry Test (2013) under GLP. The test substance, at a concentration of 18 mg/L was exposed to activated sewage sludge micro-organisms obtained from the Liede Sewage Treatment Plant of Guangzhou, China, with culture medium in sealed culture vessels in the dark at 22°C ± 2°C for 28 days. The sludge was diluted in flasks to 28 mg SS/L. within the test systems; 28 mg SS/L in the negative and toxicity controls. The degradation of the test substance was assessed by the measurement of daily oxygen consumption on days 0 and 28 using an Oxitop control system. Control solutions with inoculum and the reference substance, sodium benzoate, together with a toxicity control were used for validation purposes. The oxygen uptake of the inoculum blanks were 9.8 mg/L and 9.5 mg/L, the mean was 9.7 mg/L, less than 60 mg/L in 28d. At the end of the test, the pH values of each test vessel were within the range of 6.0-8.5. The test system therefore met the validation criteria of the guideline. The toxicity test attained 60 % degradation after 28 days thereby confirming that the test substance was not inhibitory to the sewage treatment micro-organisms used in the study. Sodium Benzoate attained 86.0 % degradation after 28 days thereby confirming the suitability of the inoculum and test conditions. The mean biodegradation for duplicate test flasks at 28 days for the test item was 71.1 % (the 10-day window was not met). The 10-day window that can be applied to Manometric Respiratory Tests, where 60% biodegradation must be achieved following the attainment of 10 % biodegradation, is not applied to multi-constituent substances consisting of structurally similar constituents (OECD, 2006). Under the conditions of the study, test item is considered as readily biodegradable.

 

OECD 301C, 2014: The ready biodegradability test was carried out according to OECD TG 301C MITI Test (I) under GLP. The test item, at a concentration of 100 mg/L was exposed to activated sewage sludge micro-organisms obtained from Chemicals Evaluation and Research Institute, Japan with culture medium in sealed culture vessels in the dark at 25°C ± 1°C for 28 days. The sludge was diluted in flasks to 30 mg SS/L. within the test systems; 30 mg SS/L in the negative and reference item controls. The degradation of the test substance was assessed by the measurement of daily oxygen consumption on days 0 and 28 using an OM-3100A Coulometer. Inoculum blank control and control solutions with inoculum and the reference substance: aniline, together with a abiotic control were used for validation purposes. The oxygen uptake of the inoculum blanks were 5.6 mg/L, less than 60 mg/L in 28d. At the end of the test, the pH values of each test vessel were within the range of 6.0-8.5. The test system therefore met the validation criteria of the guideline. The activity procedure control test using aniline attained 74% degradation after 28 days confirming the suitability of the inoculum and test conditions. The mean biodegradation for triplicate test flasks at 28 days for the test item was 83.6 % calculated by oxygen consumption. The biodegradability calculated from the concentration of dissolved organic carbon was 100% (mean) in the test suspensions. There was evidence of test item degradation and mineralisation of degradation products determined within the study. The test item was biodegraded by mean (n=3): 83.6% at day 28 in the OECD 301C MITI Test (I). The 10 or 14-day window does not apply within the OECD TG 301C MITI Test (I) or to test items consisting of homologous multi-constituent substances consisting of structurally similar constituents (OECD, 2006). Under the conditions of the study, test item is considered as readily biodegradable.

 

References:

1. ECHA Guidance on Information Requirements and Chemical Safety Assessment (Chapter R.7b: Endpoint Specific Guidance, R.7.9.4.1, June 2017)

2. Introduction to the section of the OECD Guidelines for Testing of Chemicals on Degradation and Accumulation, Section 3 (OECD, September 2006)

3. GHS revision 4 (2011), Globally harmonized system of classification and labelling of chemicals (GHS). Chapter 4.1. Hazardous to the aquatic Environment. United Nations, 2011

4. ECHA Guidance on Application on the CLP Criteria, section 4.1.3.2.3.2 (v5.0, July 2017)