4-(2-acryloyloxy-ethoxy) benzophenone

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

14 Jan - 11 Feb 2015

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Report date:

2015

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

no

Remarks:

Test done per China GLP criterion, not internationally recognized

Test material

Test material information

Constituent 1

Reference substance name:

4-(2-acryloyloxy-ethoxy) benzophenone

EC Number:

836-681-3

Cas Number:

22421-66-5

Molecular formula:

C18H16O4

IUPAC Name:

4-(2-acryloyloxy-ethoxy) benzophenone

Specific details on test material used for the study:

Lot number: 30004
Appearance: Waxy, light yellow solid
Purity: 85.7%
Purity test date: 4 March 2015
Expiration date: 17 Jun 2015

Study design

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): A fresh sample of activate sludge was collected from the aeration tank of Shenyang Northern Sewage Treatment Plant 1 (conventional treatment plant for domestic waste) one day before the test. Coarse particles were removed by filtration throug a fine sieve and the sample was settled. The settled sludge was washed twice with mineral medium and then resuspended in mineral medium. The sludge was kept aerobic at 20.3 - 22.6 °C until use. On the day of the test, five samples were weighed, dried at 105 °C for 90 minutes, and then reweighed to obtain initial sludge concentration.
- Concentration of sludge: 3992 mg suspended solids/L

Duration of test (contact time):

28 d

Initial test substance concentration

Initial test substance concentration 1

Initial conc.:

45.8 mg/L

Based on:

test mat.

Initial test substance concentration 2

Initial conc.:

99.1 mg/L

Based on:

ThOD

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: Mineral medium per OECD301
- Test temperature: 20 ± 1 °C
- pH: final values, 7.29 - 7.61
- pH adjusted: no
- Suspended solids concentration: 30 mg SS/L
- Continuous darkness: yes
- Other: Inoculated mineral medium was prepared as a single batch and measured into individual BOD bottles. Solid test material was weighed into each bottles as needed.

TEST SYSTEM
- Culturing apparatus: BOD bottles with Lovibond ET999724A BOD-system OxiDirect (automated respirometer) for measurement of oxygen depletion. Bottles kept in incubator.
- Number of culture flasks/concentration: two for inoculum blank and test samples, one each for toxicity and reference substance.
- Details of trap for CO2 and volatile organics if used: KOH solution in seal gasket of bottles.
- Other: Temperature measured hourly in incubator. BOD values measured daily

CONTROL AND BLANK SYSTEM
- Inoculum blank: duplicate
- Abiotic sterile control: none
- Toxicity control: single, containing references substance (92.6 mg ThOD/L) and test substance (94.4 mg ThOD/L)

Reference substance

Reference substance:

benzoic acid, sodium salt

Remarks:

91.9 mg ThOD/L

Results and discussion

% Degradation

% Degradation 1

Parameter:

% degradation (O2 consumption)

Value:

55.5

Sampling time:

20 d

Remarks on result:

other: result at end of 10-day window

% Degradation 2

Parameter:

% degradation (O2 consumption)

Value:

69.6

Sampling time:

28 d

Details on results:

Biodegradation of the reference substance attained 69.6% by day 3, 95.7% by day 14, and 103.3% by day 28.

Biodegradation of the toxicity control attained 51.6% by day 14, exceeding 25%.

Any other information on results incl. tables

Table 1. 28-Day Biodegradation Results of Inoculum Control (IC) and Test Substance (TS)

Day	IC-1 DO demand (mgDO/L)	IC-2 DO demand (mgDO/L)	TS-1 DO demand (mgDO/L)	TS-2 DO demand (mgDO/L)	TS-1 BOD (mg DO/mg test item)	TS-2 BOD(mg DO/mg test item)	TS avg BOD(mg DO/mg test item)	TS-1 %BOD	TS-2 %BOD	TS avg %BOD
1	1	1	3	3	0.044	0.044	0.044	2.0	2.0	2.0
2	1	1	3	3	0.044	0.044	0.044	2.0	2.0	2.0
3	1	1	3	3	0.044	0.044	0.044	2.0	2.0	2.0
4	2	1	3	3	0.033	0.033	0.033	1.5	1.5	1.5
5	2	3	5	5	0.055	0.055	0.055	2.5	2.5	2.5
6	4	5	10	11	0.120	0.142	0.131	5.6	6.6	6.1
7	5	6	12	13	0.142	0.164	0.153	6.6	7.6	7.1
8	3	6	12	13	0.164	0.185	0.175	7.6	8.6	8.1
9	3	6	14	14	0.208	0.207	0.207	9.6	9.6	9.6
10	4	6	16	14	0.240	0.196	0.218	11.1	9.1	10.1
11	4	6	18	16	0.284	0.240	0.262	13.1	11.1	12.1
12	3	6	19	22	0.317	0.382	0.349	14.6	17.6	16.1
13	4	7	23	29	0.382	0.512	0.447	17.7	23.7	20.7
14	5	7	30	33	0.524	0.589	0.557	24.2	27.2	25.7
15	5	7	32	37	0.568	0.676	0.622	26.3	31.3	28.8
16	5	7	35	42	0.633	0.785	0.709	29.3	36.3	32.8
17	6	7	38	48	0.688	0.905	0.797	31.8	41.9	36.8
18	7	8	43	55	0.775	1.036	0.906	35.9	47.9	41.9
19	7	8	50	61	0.928	1.167	1.047	42.9	54.0	48.4
20	7	8	57	68	1.081	1.319	1.200	50.0	61.0	55.5
21	7	9	60	72	1.136	1.396	1.266	52.5	64.5	58.5
22	7	9	62	74	1.180	1.439	1.309	54.6	66.6	60.6
23	8	9	64	76	1.212	1.472	1.342	56.1	68.1	62.1
24	8	9	66	78	1.256	1.515	1.386	58.1	70.1	64.1
25	8	9	68	80	1.300	1.559	1.429	60.1	72.1	66.1
26	9	11	70	82	1.311	1.570	1.440	60.6	72.6	66.6
27	9	11	72	84	1.354	1.614	1.484	62.6	74.6	68.6
28	9	11	73	85	1.376	1.635	1.506	63.6	75.6	69.6

The difference of extremes of replicate values of the removal of the test item at the end of the test was 12%.

Table 2. 28-Day Biodegradation Results of Toxicity Control (TC) and Procedural Control (PC)

Day	TC DO demand (mgDO/L)	PC DO demand (mgDO/L)	TC BOD (mgDO/mg test item)	PC BOD (mgDO/mg test item)	TC %BOD	PC %BOD
1	40	46	0.393	0.815	20.5	48.9
2	54	56	0.534	0.996	27.9	59.8
3	68	65	0.675	1.159	35.3	69.6
4	76	70	0.751	1.241	39.2	74.5
5	85	78	0.831	1.368	43.4	82.1
6	91	84	0.871	1.440	45.5	86.5
7	93	87	0.882	1.476	46.1	88.6
8	95	88	0.912	1.513	47.6	90.8
9	96	87	0.922	1.494	48.2	89.7
10	98	89	0.937	1.522	49.0	91.4
11	100	91	0.957	1.558	50.0	93.5
12	101	92	0.972	1.585	50.8	95.2
13	103	93	0.982	1.585	51.3	95.2
14	104	94	0.987	1.594	51.6	95.7
15	106	95	1.007	1.612	52.6	96.8
16	108	97	1.028	1.648	53.7	99.0
17	110	97	1.043	1.639	54.5	98.4
18	112	98	1.053	1.639	55.0	98.4
19	115	99	1.083	1.657	56.6	99.5
20	118	100	1.113	1.676	58.2	100.6
21	123	101	1.159	1.685	60.5	101.1
22	129	101	1.219	1.685	63.7	101.1
23	137	102	1.295	1.694	67.6	101.7
24	145	101	1.375	1.676	71.9	100.6
25	149	102	1.415	1.694	74.0	101.7
26	153	104	1.441	1.703	75.3	102.2
27	155	104	1.461	1.703	76.3	102.2
28	157	105	1.481	1.721	77.4	103.3

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

oxygen uptake of the inoculum blank <60 mg/l in 28 days (10 mg/L), degradation of the reference substance reached pass level by day 14 (day 3), extremes of replicate BODs at the end of the test is less than 20% (12%).

Interpretation of results:

readily biodegradable, but failing 10-day window

Conclusions:

69.6% BOD/ThOD in 28 days, 10 day window exceeded (OECD301F)

Executive summary:

Aryloxyacrylate biodegradation 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 substance attained 10.1% average degradation on day 10 and exceeded 60% average degradation on day 22. The toxicity control result (52% BOD on day 14) showed that aryloxyacrylate is not inhibitory to biodegradation. Aryloxyacrylate is readily biodegradable but fails the 10-day window.

The test was conducted under an international test guideline and was compliant with local GLP criteria. While the study is otherwise of acceptable quality, local GHS is not accepted internationally. Therefore, the study was deemed reliable with restrictions and suitable for use in Risk Assessment, Classification & Labelling, and PBT Analysis.