Reactionmass of octan-2-yl prop-2-enoate and octan-3-yl prop-2-enoate and octan-4-yl prop-2-enoate

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 Jun - 19 Jul 2019

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)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: 3M FMRD, S352546
- Expiration date: 2020.05.01
- Purity: 99.7%
- Physical state: Clear and colorless liquid

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Stored at room temperature (15-25°C).
- Stability under test conditions: Not stable

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): sludge was collected from the aeration tank of Shenyang North Sewage Treatment Plant (a well functioning treatment plant receiving predominantly domestic sewage).
- Storage conditions: aerated at 21.9 - 23.3 °C until used
- Storage length: 2 days
- Pretreatment: coarse particles were removed by filtration through a fine sieve and the sample was settled. After the supernatant was discarded, the sludge was washed twice with mineral medium and the concentrated sludge was suspended in mineral medium. On the day of the test 5 replicates of 10 mL suspended sludge were weighed, dried at 105 °C for 1.83 hours, and reweighed to calculate initial sludge concentration.
- Concentration of sludge: 3854 mg/L as suspended solids

Duration of test (contact time):

28 d

Initial conc.:

20.53 mg/L

Based on:

test mat.

Initial conc.:

53.38 mg/L

Based on:

ThOD

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: per OECD 301
- Additional substrate: No
- Solubilising agent: None
- Test temperature: 21.1-22.7 °C
- pH adjusted: No
- Suspended solids concentration: 30 mg/L
- Continuous darkness: No. The test was conducted in diffuse light
- Other: Test substance ThOD, 2.60 mg O2/mg test item.

TEST SYSTEM
- Culturing apparatus: CES respirometric system, Co-ordinated Environmental Services, Ltd., UK. Test flasks were stirred in a constant temperature bath
- Number of culture flasks/concentration: Two
- Method used to create aerobic conditions: Magnetic stirring, electrolytic oxygen generator
- Measuring equipment: Sensor head closing each flask
- Details of trap for CO2 and volatile organics if used: 4 mL 10 M NaOH in sensor head

SAMPLING
- Sampling frequency: None, pressure in test flasks was monitored every 24 hours by automated recording equipment through sensor head.

CONTROL AND BLANK SYSTEM
- Inoculum blank: Duplicate
- Abiotic sterile control: None
- Toxicity control: Single flask containing 51.87 mg/L ThOD from test material and 53.34 mg/L ThOD from reference substance.

Reference substance:

benzoic acid, sodium salt

Key result

Parameter:

% degradation (O2 consumption)

Value:

54.7

Sampling time:

28 d

Details on results:

- The oxygen uptake of the inoculum blank was 21.88 mg O2/L in 28 days (Table 1)
- Final pH values ranged from 7.48 - 7.95.
- Biodegradation values of MTDID 44428 in the replicate were 53.2% and 56.2% (Table 1)
- In the toxicity control, 35.6% degradation occurred within 2 days and 70.6% within 14 days based on total ThOD (Table 2). Since these values exceeded the 25% ThOD limit for the toxicity control, it was concluded that the test item is not inhibitory to sludge micro-organisms.

Results with reference substance:

Degradation of the reference substance reached 63.5% ThOD after 3 days, and was 97.8% ThOD after 14 days (Table 2).

Table 1, Dissolved oxygen (DO) demand and BOD for test substance and inoculum controls

Day	IC-1DO demand (mgDO/L)	IC-2DO demand (mgDO/L)	TS-1DO demand (mgDO/L)	TS-2DO demand (mgDO/L)	IC avg DO demand (mgDO/L)	TS-1 BOD (mgDO/mg test item)	TS-2 BOD(mg O/mg test item)	TS avg BOD(mgDO/mg test item)	TS-1 %BOD	TS-2 %BOD	TS avg %BOD
1	1.73	1.73	2.08	2.33	1.73	0.017	0.029	0.023	0.7	1.1	0.9
2	4.56	4.62	14.64	15.95	4.59	0.499	0.543	0.521	19.2	20.9	20.1
3	7.41	7.52	21.49	22.47	7.47	0.696	0.717	0.707	26.8	27.6	27.2
4	9.48	9.37	25.72	26.51	9.43	0.809	0.816	0.813	31.1	31.4	31.3
5	10.66	10.35	29.63	29.99	10.51	0.949	0.931	0.940	36.5	35.8	36.2
6	11.60	11.10	32.61	33.01	11.35	1.056	1.035	1.046	40.6	39.8	40.2
7	12.74	12.06	35.57	36.05	12.40	1.150	1.130	1.140	44.2	43.5	43.9
8	13.74	12.91	38.53	39.01	13.33	1.251	1.228	1.240	48.1	47.2	47.7
9	14.60	13.77	41.09	41.57	14.19	1.336	1.309	1.323	51.4	50.3	50.9
10	15.41	14.45	43.05	43.40	14.93	1.396	1.361	1.379	53.7	52.3	53.0
11	16.08	14.99	44.75	44.57	15.54	1.450	1.388	1.419	55.8	53.4	54.6
12	16.91	15.76	46.25	45.75	16.34	1.485	1.406	1.446	57.1	54.1	55.6
13	17.43	16.29	47.11	46.65	16.86	1.502	1.424	1.463	57.8	54.8	56.3
14	18.03	16.89	47.94	47.50	17.46	1.513	1.436	1.475	58.2	55.2	56.7
15	18.60	17.45	48.65	48.31	18.03	1.520	1.447	1.484	58.5	55.7	57.1
16	19.26	18.08	49.38	49.11	18.67	1.525	1.455	1.490	58.7	56.0	57.4
17	19.74	18.51	49.83	49.63	19.13	1.524	1.458	1.491	58.6	56.1	57.4
18	20.18	18.91	50.23	49.98	19.55	1.523	1.455	1.489	58.6	56.0	57.3
19	20.62	19.33	50.44	50.21	19.98	1.512	1.445	1.479	58.2	55.6	56.9
20	21.07	19.74	50.56	50.29	20.41	1.497	1.428	1.463	57.6	54.9	56.3
21	21.39	20.03	50.60	50.29	20.71	1.484	1.414	1.449	57.1	54.4	55.8
22	21.68	20.30	50.60	50.29	20.99	1.470	1.401	1.436	56.5	53.9	55.2
23	21.89	20.53	50.63	50.33	21.21	1.461	1.392	1.427	56.2	53.5	54.9
24	22.01	20.70	50.71	50.44	21.36	1.457	1.390	1.424	56.0	53.5	54.8
25	22.12	20.74	50.81	50.44	21.43	1.459	1.387	1.423	56.1	53.3	54.7
26	22.30	20.80	50.96	50.50	21.55	1.460	1.384	1.422	56.2	53.2	54.7
27	22.53	20.83	51.04	50.63	21.68	1.458	1.384	1.421	56.1	53.2	54.7
28	22.80	20.95	51.29	50.83	21.88	1.460	1.384	1.422	56.2	53.2	54.7

Note: IC = Inoculum Control; TS = Test Substance.

The difference of extremes of replicate values of the removal of the test substance at the end of the test was 0.4%

Table 2, Dissolved oxygen (DO) demand and BOD for Procedural and toxicity controls v. inoculum controls

Day	IC-1DO demand (mgDO/L)	IC-2DO demand (mgDO/L)	TC DO demand (mgDO/L)	PC DO demand (mgDO/L)	IC avg DO demand (mgDO/L)	PC BOD (mgDO/mg test item)	TC %BOD	PC %BOD
1	1.73	1.73	17.89	19.28	1.73	0.569	15.4	34.1
2	4.56	4.62	42.05	33.36	4.59	0.932	35.6	55.8
3	7.41	7.52	50.50	40.21	7.47	1.061	40.9	63.5
4	9.48	9.37	58.00	45.67	9.43	1.174	46.2	70.3
5	10.66	10.35	63.91	50.15	10.51	1.285	50.8	76.9
6	11.60	11.10	69.08	53.71	11.35	1.373	54.9	82.2
7	12.74	12.06	73.87	56.83	12.40	1.440	58.4	86.2
8	13.74	12.91	78.34	59.33	13.33	1.491	61.8	89.3
9	14.60	13.77	81.26	61.18	14.19	1.523	63.7	91.2
10	15.41	14.45	83.36	62.81	14.93	1.552	65.0	92.9
11	16.08	14.99	86.17	64.25	15.54	1.578	67.1	94.5
12	16.91	15.76	88.59	65.81	16.34	1.603	68.7	96.0
13	17.43	16.29	90.30	66.87	16.86	1.621	69.8	97.1
14	18.03	16.89	91.71	67.87	17.46	1.634	70.6	97.8
15	18.60	17.45	92.25	68.76	18.03	1.644	70.5	98.4
16	19.26	18.08	92.25	69.68	18.67	1.653	69.9	99.0
17	19.74	18.51	92.25	70.39	19.13	1.661	69.5	99.5
18	20.18	18.91	92.25	71.03	19.55	1.668	69.1	99.9
19	20.62	19.33	92.25	71.68	19.98	1.675	68.7	100.3
20	21.07	19.74	92.25	72.35	20.41	1.683	68.3	100.8
21	21.39	20.03	92.25	72.83	20.71	1.689	68.0	101.1
22	21.68	20.30	92.25	73.26	20.99	1.694	67.7	101.4
23	21.89	20.53	92.25	73.60	21.21	1.698	67.5	101.7
24	22.01	20.70	92.25	73.85	21.36	1.701	67.4	101.9
25	22.12	20.74	92.25	74.10	21.43	1.707	67.3	102.2
26	22.30	20.80	92.25	74.45	21.55	1.714	67.2	102.6
27	22.53	20.83	92.25	74.89	21.68	1.724	67.1	103.2
28	22.80	20.95	92.25	75.30	21.88	1.731	66.9	103.7

Note: IC = Inoculum Control; TC=Toxicity Control; PC = Procedural Control.

The percentage biodegradation of the TC was based on total ThOD, BOD (mgDO/mg test item) was not calculated.

% degradation of TC = 100% * [DO uptake (TC) - O2 uptake(IC avg)]/Total ThOD(TC)

Validity criteria fulfilled:

yes

Remarks:

28 day DO uptake in blanks < 60 mg/L (22 mg/L), pH in range 6 - 8.5 (pH 7.5 - 8.0), < 20% difference in sample %BOD at end of test (3.0%), ref substance >70% BOD by Day 14 (97.8%). Test substance not inhibitory (70.6% BOD in toxicity control on Day 14).

Interpretation of results:

inherently biodegradable

Conclusions:

28-day MTDID 44428 biodegradation, 54.7% BOD (OECD301F)

Executive summary:

Biodegradability of MTDID 44428 was assessed according to guideline OECD 301F (manometric respirometry). Duplicate samples and a single toxicity control were tested with sodium benzoate as reference substance. The toxicity control showed that MTDID 44428 is not inhibitory to biodegradation. MTDID 44428 is not readily biodegradable, but is inherently biodegradable. It cannot be determined from this test whether MTDID 44428 meets specific criteria for inherent biodegradation.

The test was conducted under an international test guideline and was GLP compliant. It is reliable without restriction and suitable for use in Risk Assessment, Classification & Labelling, and PBT Analysis.

Reference 2

Endpoint:

biodegradation in water: inherent biodegradability

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

01 - 29 Aug 2019

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 302 C (Inherent Biodegradability: Modified MITI Test (II))

Deviations:

yes

Remarks:

60-mesh screen used instead of No. 2 filter paper to prepare sludge

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: 3M FMRD, S352546
- Expiration date: 2020.05.01
- Purity: 99.7%
- Physical state: Clear and colorless liquid
STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Stored at room temperature (15-25°C).
- Stability under test conditions: Not stable

Oxygen conditions:

aerobic

Inoculum or test system:

mixture of sewage, soil and natural water

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): Fresh samples were collected from ten sites including aeration tank of Shenyang North Sewage Treatment Plant, sewage outfall of Shenshuiwan Sewage Treatment Plant, sewage outfall of Shenyang Xiannvhe Sewage Treatment Plant, Weigong Channel, Xinkai River, Beiling Park, Maguan Bridge, Nanhu Park, Hunhe River, and Xihe Bridge, on May 08, 2019. Samples of sludge, surface soil, water, etc. were collected and 3 liters were mixed by stirring in a single container. After floating matter was removed and the mixed sample was allowed to stand, the supernatant was filtered through a 60 mesh sieve. The filtrate was divided into two fill-and-draw activated sludge vessels and aerated overnight.
- Laboratory culture: Daily, the aeration was stopped for 30 minutes. After settling, ca. one-third of the total supernatant volume was removed and the same volume of 0.1% synthetic sewage (composition per OECD 302C) was added and aeration restarted. The temperature was kept at 23.9 - 25.9°C and the pH at 7.0 ± 1.0. The sludge was sufficiently aerated to keep the mixture aerobic at all times. The sludge was monitored for quality on a weekly basis. Culture was maintained for 84 days, whereupon the sludge was considered ready for use.
- Sludge quality:
Appearance of supernatant: the supernatant of the active sludge was clear;
State of formation of active sludge: growth of flocks was observed;
Precipitability: the active sludge, being in large flocks, had high precipitability;
pH: pH of the supernatant was 6.32 - 7.42;
Aerobic conditions: dissolved oxygen concentration of the solution was 5.21 - 6.25 ppm;
Microflora: When the active sludge was microscopically observed, a number of protozoa of different species together with cloudy flocks were seen.
- Pretreatment: One day before the test, ca. one liter of prepared sludge was washed twice in mineral medium by centrifugation (5 min at 1500 RPM), and then resuspended in mineral medium to ca 800 mL total volume. The washed sludge was aerated overnight at 24.6 - 25.8 °C. On the day of the test, five 10-mL samples were dried 90 minutes at 105 °C to determine sludge concentration.
- Concentration of sludge: 7132 mg/L

Duration of test (contact time):

28 d

Initial conc.:

30.42 mg/L

Based on:

test mat.

Remarks:

average across triplicate

Initial conc.:

79.1 mg/L

Based on:

ThOD

Remarks:

ThOD is 2.60 mg O2/mg

Parameter followed for biodegradation estimation:

O2 consumption

Parameter followed for biodegradation estimation:

test mat. analysis

Details on study design:

TEST CONDITIONS
- Composition of medium: per OECD 302C
- Additional substrate: No
- Test temperature: 24.7 °C - 26.0 °C
- pH: Test substance, 6.69-6.74; test substance inoculum controls, 6.37-6.39; reference substance, 7.82; reference substance inoculum control, 6.91; abiotic control, 7.69; abiotic control blank, 8.40.
- pH adjusted: no
- Aeration of dilution water: No
- Suspended solids concentration: 100 mg/L for test substance, 30 mg/L for reference substance, 0 mg/L for abiotic blank
- Continuous darkness: yes

TEST SYSTEM
- Culturing apparatus: CES respirometric system, Co-ordinated Environmental Services, Ltd., UK. Test flasks were stirred in a constant temperature bath
- Number of culture flasks: Three for test substance, two for test substance inoculum control, one each for reference substance, reference substance inoculum control, abiotic control, and abiotic control blank
- Method used to create aerobic conditions: Magnetic stirring, electrolytic oxygen generator
- Measuring equipment: Sensor head closing each flask
- Details of trap for CO2 and volatile organics if used: 4 mL 10 M NaOH in sensor head

SAMPLING
- Sampling frequency: Pressure in test flasks was monitored every 24 hours by automated recording equipment through sensor head. Analytical determination at end of test only.
- Sampling method: Entire flask extracted, no subsampling.
- Sample storage before analysis: Samples extracted immediately

CONTROL AND BLANK SYSTEM
- Inoculum blank: Yes, separate blanks for test substance, reference substances, and abiotic controls
- Abiotic sterile control: Yes
- Toxicity control: No

Reference substance:

benzoic acid, sodium salt

Remarks:

96.31 mg/L

Key result

Parameter:

% degradation (O2 consumption)

Value:

67

Sampling time:

28 d

Details on results:

- The average oxygen uptake of the inoculum blank was 113.35 mg O2/L in 28 days (Table 1)
- Biodegradation values of MTDID 44428 in the replicate were 71.3%, 64.8%, and 64.8% (Table 2)
- In samples analyzed at the end of the test, MTDID 44428 concentrations were

Results with reference substance:

76.4% BOD on day 7 and 86.4% BOD on Day 14 (See Table 3)

Table 1. Oxygen uptake of test substance in inoculum controls (IC-1, IC-2) and test vessels (mg DO/L)

Day	IC-1	IC-2	IC average	Test 1	Test 2	Test 3
1	10.85	11.18	11.02	16.18	17.16	16.01
2	23.18	24.01	23.60	41.46	43.73	39.67
3	31.80	32.99	32.40	58.93	62.41	55.19
4	38.51	39.65	39.08	68.99	73.03	63.95
5	43.96	44.69	44.33	76.84	81.07	71.70
6	48.48	49.00	48.74	84.40	89.42	79.91
7	53.02	53.42	53.22	91.21	97.59	87.22
8	57.83	58.00	57.92	97.25	104.50	93.75
9	62.87	62.64	62.76	102.81	110.41	99.75
10	68.70	67.89	68.30	108.60	116.06	106.06
11	75.53	73.74	74.64	114.89	121.60	113.20
12	82.22	79.70	80.96	121.08	126.30	120.47
13	88.69	86.94	87.82	128.99	133.72	129.57
14	93.86	93.30	93.58	136.07	142.03	138.97
15	96.63	97.13	96.88	141.05	147.57	145.53
16	99.31	100.04	99.68	145.61	151.56	150.71
17	101.44	102.44	101.94	149.54	154.35	154.46
18	103.71	104.62	104.17	152.86	156.60	157.31
19	105.00	105.96	105.48	154.90	158.12	158.79
20	105.94	107.39	106.67	157.10	159.77	160.12
21	107.19	108.96	108.08	159.62	161.44	161.71
22	107.67	109.73	108.70	161.27	162.06	162.41
23	108.21	110.71	109.46	162.91	162.54	162.85
24	108.96	111.91	110.44	164.60	163.33	163.35
25	109.23	112.64	110.94	165.66	163.50	163.43
26	109.48	113.37	111.43	166.66	163.64	163.77
27	110.16	114.70	112.43	168.18	164.04	164.27
28	110.62	116.08	113.35	169.54	164.58	164.81

Table 2, BOD (mg DO/mg) and % Biodegradation in test samples

Day	Test 1 BOD	Test 2 BOD	Test 3 BOD	Test 1 %Biodeg	Test 2 %Biodeg	Test 3 %Biodeg	Average %Biodeg
1	0.170	0.202	0.163	6.5	7.8	6.3	6.9
2	0.589	0.662	0.526	22.7	25.5	20.2	22.8
3	0.875	0.987	0.746	33.7	38.0	28.7	33.5
4	0.987	1.117	0.814	38.0	43.0	31.3	37.4
5	1.073	1.209	0.896	41.3	46.5	34.5	40.8
6	1.177	1.338	1.020	45.3	51.5	39.2	45.3
7	1.253	1.460	1.113	48.2	56.2	42.8	49.1
8	1.298	1.532	1.172	49.9	58.9	45.1	51.3
9	1.321	1.567	1.210	50.8	60.3	46.5	52.5
10	1.330	1.571	1.236	51.2	60.4	47.5	53.0
11	1.328	1.545	1.262	51.1	59.4	48.5	53.0
12	1.324	1.491	1.293	50.9	57.3	49.7	52.6
13	1.358	1.510	1.366	52.2	58.1	52.5	54.3
14	1.402	1.594	1.485	53.9	61.3	57.1	57.4
15	1.457	1.667	1.592	56.0	64.1	61.2	60.4
16	1.515	1.707	1.670	58.3	65.7	64.2	62.7
17	1.570	1.724	1.719	60.4	66.3	66.1	64.3
18	1.606	1.725	1.739	61.8	66.3	66.9	65.0
19	1.630	1.732	1.744	62.7	66.6	67.1	65.5
20	1.664	1.747	1.749	64.0	67.2	67.3	66.2
21	1.700	1.755	1.755	65.4	67.5	67.5	66.8
22	1.734	1.755	1.758	66.7	67.5	67.6	67.3
23	1.763	1.746	1.747	67.8	67.2	67.2	67.4
24	1.787	1.740	1.731	68.7	66.9	66.6	67.4
25	1.805	1.729	1.718	69.4	66.5	66.1	67.3
26	1.822	1.717	1.713	70.1	66.0	65.9	67.3
27	1.839	1.698	1.696	70.7	65.3	65.2	67.1
28	1.854	1.685	1.684	71.3	64.8	64.8	67.0

Table 3. Oxygen uptake, BOD, and % Biodeg in Procedural Control

Day	Inoculum control uptake (mg/L)¹	Procedural control uptake (mg/L)	BOD (mg DO/mg)	% Biodegradation
1	5.04	37.28	0.335	20.1
2	10.45	70.83	0.627	37.5
3	15.89	101.29	0.887	53.1
4	20.20	124.08	1.079	64.6
5	22.47	135.90	1.178	70.5
6	24.26	143.57	1.239	74.2
7	26.03	148.92	1.276	76.4
8	27.74	153.67	1.308	78.3
9	29.24	158.35	1.341	80.3
10	30.99	162.89	1.370	82.0
11	33.05	166.91	1.390	83.2
12	34.19	169.89	1.409	84.4
13	36.59	173.78	1.424	85.3
14	39.38	178.37	1.443	86.4
15	40.61	181.14	1.459	87.4
16	41.98	183.76	1.472	88.1
17	43.27	186.24	1.484	88.9
18	44.71	188.61	1.494	89.5
19	45.40	190.13	1.503	90.0
20	46.19	191.82	1.512	90.5
21	47.38	193.84	1.521	91.1
22	47.84	195.07	1.529	91.6
23	48.33	196.38	1.537	92.0
24	49.04	197.84	1.545	92.5
25	49.25	198.84	1.553	93.0
26	49.50	199.84	1.561	93.5
27	50.15	201.32	1.570	94.0
28	50.69	202.69	1.578	94.5

1, Procedural control flask had its own inoculum control

Table 4. Test substance analysis at end of degradation period

Test vessel	Measured conc. in extract (mg/L)			Dilution factor	Conc. in test vessel (mg/L)	Residual conc. (%)
	Comp. 1¹	Comp. 2	Comp. 3		Final
TS-1	<LOD	<LOD	<LOD	20	<0.1²	<0.3²
TS-2	<LOD	<LOD	<LOD	20	<0.1	<0.3
TS-3	<LOD	<LOD	<LOD	20	<0.1	<0.3
Abiotic	0.0126	0.0105	0.0063	50	1.47	4.8

1. Component 1, 26.6% of MTDID 44428; Component 2, 34.2% of MTDID 44428; Component 3, 38.9% of MTDID 44428

2. Residual concentration =  100 * (measured concentration in test vessel/initial concentration [i.e, 30.86 mg/L])

Validity criteria fulfilled:

no

Remarks:

>10% recovery of analyte in abiotic control (4.8%). Other validity criteria were met [Reference substance > 40% BOD on day 7 (76.4%) and >65% on day 14 (86.4%)].

Interpretation of results:

inherently biodegradable, not fulfilling specific criteria

Conclusions:

28-day MTDID 44428 biodegradation, 67.0% BOD (OECD302C)

Executive summary:

Biodegradability of MTDID 44428 was assessed according to guideline OECD 302C (MITI-II method). Triplicate samples were tested with sodium benzoate as reference substance. MTDID 44428 is inherently biodegradable but does not meet specific criteria. It should be noted that the test material concentration at end of test was at levels <LOD in test vessels, but was 4.8% of initial in abiotic controls. It is known that stable concentrations of the test substance cannot be maintained in aqueous solution. The current result can be accepted with this understanding. It is possible that biodegradation of this material is underreported due to loss of available material. However, the results are conservatively reported as such.

The test was conducted under an international test guideline and was GLP compliant. However, as noted the test material may not have been present in degradable form throughout the test. It is therefore reliable with restrictions and suitable for use in Risk Assessment, Classification & Labelling, and PBT Analysis.

Description of key information

54.7% BOD/ThOD in a 28-day OECD 301F test

67% BOD/ThOD in a 28-day OECD 302C test

Key value for chemical safety assessment

Biodegradation in water:

inherently biodegradable, not fulfilling specific criteria

Type of water:

freshwater

Additional information

Biodegradation potential of MTDID 44428 was assessed in a ready biodegradability test according to guideline OECD 301F (manometric respirometry) and an inherent biodegradability test according to guideline OECD 302C.  In the ready test, MTDID 44428 had 54.7% BOD/ThOD and was not inhibitory to biodegradation in the toxicity control. Based on this result, MTDID 44428 is not readily biodegradable, but is inherently biodegradable.  In the inherent test, a final biodegradation value of 67% BOD/ThOD in 28 days was measured, but the substance did not meet specific criteria. It could not be detected in abiotic samples at the end of the test. Test material concentrations are known to be non-stable in aqueous solution, and it is possible that the test material was no longer available for biodegradation throughout the test period.  However, the results of the study are conservatively reported as such.