Reaction mass of (((1,3-phenylenebis(oxy))bis(ethane-2,1-diyl))bis(oxy))bis(ethane-2,1-diyl) bis(2-methylacrylate) and (1,3-phenylenebis(oxy))bis(propane-3,1-diyl) bis(2-methylacrylate) and 3-(3-(2-(2-(methacryloyloxy)ethoxy)ethoxy)phenoxy)propyl methacrylaterate

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:

31st July - 28th August, 2019

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2020

Report date:

2020

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Reaction mass of (((1,3-phenylenebis(oxy))bis(ethane-2,1-diyl))bis(oxy))bis(ethane-2,1-diyl) bis(2-methylacrylate) and (1,3-phenylenebis(oxy))bis(propane-3,1-diyl) bis(2-methylacrylate) and 3-(3-(2-(2-(methacryloyloxy)ethoxy)ethoxy)phenoxy)propyl methacrylaterate

EC Number:

944-271-1

Cas Number:

2305048-54-6

Molecular formula:

not applicable for multi-constituent.

IUPAC Name:

Reaction mass of (((1,3-phenylenebis(oxy))bis(ethane-2,1-diyl))bis(oxy))bis(ethane-2,1-diyl) bis(2-methylacrylate) and (1,3-phenylenebis(oxy))bis(propane-3,1-diyl) bis(2-methylacrylate) and 3-(3-(2-(2-(methacryloyloxy)ethoxy)ethoxy)phenoxy)propyl methacrylaterate

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch number of test material: 3M Maplewood, Lot# 653940
- Expiration date of the lot/batch: February 2020
- Purity test date: 26th February 2019
- Purity: 100% (UVCB)
- Physical state:yellowish to reddish liquid

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room temperature in a dark, ventialted cabinet in the original container.
- Stability under storage conditions: Stable
- Stability under test conditions: Stable

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): Sludge was obtained from Wareham Wastewater Treatment Plant, Wareham Massachusetts. Collected 30th July, 2019.
- Preparation of inoculum for exposure: Sludge was passed through a 2mm sieve and centrifuged for 10 minutes (1000 rpm). Supernatant was discarded and the sludge was washed with mineral medium. The sludge was then centrifuged again and the supernatant discarded.
- Pretreatment: Inoculum solution with 15 mg dry solids/mL was prepared by diluting 69.00 g wet sludge to 200mL mineral medium. The sludge solution was stirred with a PTFE-coated magnetic bar and aerated at 22 °C until use. Sludge was used the following day and was not fed.
- Concentration of sludge: 30 mg solids/L in test bottles

Duration of test (contact time):

28 d

Initial test substance concentration

Initial test substance concentration 1

Initial conc.:

20.58 mg/L

Based on:

test mat.

Initial test substance concentration 2

Initial conc.:

10 mg/L

Based on:

TOC

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium: Mineral medium made in reagent grade water per OECD 301 guideline, with substitution of anhydrous disodium phosphate.
- Additional substrate: none
- Solubilising agent: none
- Test temperature: 19.3 - 22.0°C
- pH: initial 7.43, final 7.07-7.21
- pH adjusted: No
- Suspended solids concentration: 15 mg/L
- Continuous darkness: Yes

TEST SYSTEM
- Culturing apparatus: 4L glass bottle with rubber stopper, 3-L fill volume.
- Number of culture flasks/concentration: two
- Method used to create aerobic conditions: Vessels were attached to CO2-free compressed air gas tank and aerated under positive pressure.
- Measuring equipment: The samples removed from the KOH trap were analysed using a Shimadzu TOC V-CPH or TOC-L/ASI-L/SSM Carbon Analyzer.
- Test performed in closed vessels due to significant volatility of test substance: No
- Test performed in open system: No
- Details of trap for CO2 and volatile organics if used: Two CO2 effluent gas traps. The first with 200mL of 0.2N KOH traps and the second with 100 mL of 0.2N KOH. The traps were left in it position throughout the test period.

SAMPLING
- Sampling frequency: Days 1, 2, 5, 7, 9, 12, 14, 16, 19, 23 and 28
- Sampling method: 7mL of trap solution was removed from the first KOH carbon dioxide trap on each test and analyzed for CO2 evolution.
- Sample storage before analysis: None

CONTROL AND BLANK SYSTEM
- Inoculum blank: duplicate
- Procedural control: 10 mg C/L sodium benzoate
- Toxicity Control: 10 mg C/L DiBrORMA, 10 mg C/L sodium benzoate

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

% Degradation

Key result

Parameter:

% degradation (CO2 evolution)

Value:

3.69

Sampling time:

28 d

Details on results:

Detailed results on carbon dioxide evolution of the test substance are provided in Table 2 and are graphically depicted in the illustration.
Detailed results on carbon dioxide evolution by the reference substance and in the toxicity control are provided in Table 2.
Raw data results on carbon dioxide evolution in the blank control are provided in Table 1.
The reference substance was 89.52% degraded by day 14.
Biodegradation in the toxicity control was 43.02% by day 14 and is therefore DiBrORMA is not toxic to activated sludge.

Any other information on results incl. tables

Table 1. MTDID 49922 Determination of the Biodegradability- Total Inorganic Carbon (mg C/L) Measured in Potasium Hydroxide Trapping Solutions.

Replicate	TIC (mg C/L) Day 1	TIC (mg C/L) Day 2	TIC (mg C/L) Day 5	TIC (mg C/L) Day 7	TIC (mg C/L) Day 9	TIC (mg C/L) Day 12	TIC (mg C/L) Day 14	TIC (mg C/L) Day 16	TIC (mg C/L) Day 19	TIC (mg C/L) Day 23	TIC (mg C/L) Day 28 - Trap 1	TIC (mg C/L) Day 28 -Trap 2
Test suspension A	7.454	10.21	19.55	24.66	29.97	38.41	43.59	47.81	55.09	67.14	85.72	15.07
Test suspension B	7.914	9.958	18.10	22.81	28.11	36.84	42.97	48.59	57.29	70.38	92.8	13.19
Inoculum Blank A	7.376	10.95	19.43	23.44	28.93	36.84	42.16	47.61	54.68	65.86	81.35	14.69
Inoculum Blank B	7.373	11.45	17.51	23.70	28.04	34.81	40.39	46.04	51.31	64.05	81.07	14.09
Procedural control*	17.52	58.51	117.8	141.0	156.6	174.0	187.3	193.1	201.6	215.7	235.3	30.36
Toxicity control	12.99	51.83	111.7	134.0	148.6	170.0	182.3	190.6	205.9	225.6	253.9	23.22

* sodium benzoate

Note: The following equation was used to determine evolved CO2: mg CO2 from test vessel=((TIC mg/L x 3.667) x Vol. KOH Tx[L])+ Sum [(TIC mg/L in previous aliquots removed x 0.007 L x 3.667)]

Where: 3.667 is the converstion factor (44/12) for carbon to carbon dioxide.

Vol. KOH Tx is the volume of KOH trap at the particular sampling interval.

0.007 L is the KOH sampling volume (7.0 mL)

Table 2. MTDID 49922 Determination of the Biodegradability: Cumulative CO2 (mg) Evolved from the Test Vessels.

Vessel	Replicate	Day 1	Day 2	Day 5	Day 7	Day 9	Day 12	Day 14	Day 16	Day 19	Day 23	Day 28
1	Test suspension A	5.47	7.42	13.79	17.14	20.49	25.60	28.60	30.94	34.78	40.83	55.22
2	Test suspension B	5.80	7.25	12.80	15.90	19.24	24.52	28.07	31.18	35.78	42.35	57.88
	Mean	5.64	7.33	13.30	16.52	19.86	25.06	28.34	31.06	35.28	41.59	56.55
	Std Dev	0.24	0.12	0.70	0.88	0.89	0.76	0.37	0.18	0.71	1.08	1.88
3	Inoculum Blank A	5.41	7.94	13.72	16.36	19.82	24.60	27.69	30.70	34.44	40.05	52.82
4	Inoculum Blank B	5.41	8.29	12.43	16.49	19.23	23.32	26.56	29.68	32.47	38.87	52.15
	Mean	5.41	8.12	13.07	16.42	19.52	23.96	27.12	30.19	33.45	39.46	52.49
	Std Dev	0.00	0.25	0.92	0.09	0.42	0.91	0.80	0.72	1.39	0.84	0.48
5	Procedural control	12.85	41.86	82.30	97.53	107.37	117.89	125.60	128.81	133.30	140.38	160.86
6	Toxicity control	9.53	37.02	77.85	92.49	101.70	114.64	121.77	126.37	134.45	144.34	166.35

The following equation was used to determine % biodegradation: % Ultimate Biodegradability= (mg CO2 produced[replicate - blank mean]/ [mg TOC added x 3.667]) x 100

Table 3. MTDID 49922 Determination of the Biodegradability- Cumulative Net Percent CO2 Evolved from the Test Vessels (Ultimate Biodegradation)

Vessel	Replicate	Day 1	Day 2	Day 5	Day 7	Day 9	Day 12	Day 14	Day 16	Day 19	Day 23	Day 28
1	Test suspension A	0.05	-0.64	0.65	0.65	0.88	1.49	1.34	0.67	1.21	1.25	2.48
2	Test suspension B	0.36	-0.79	-0.25	-0.48	-0.26	0.51	0.86	0.90	2.11	2.63	4.90
	Mean	0.21	-0.71	0.20	0.09	0.31	1.00	1.10	0.79	1.66	1.94	3.69
	Std Dev	0.22	0.11	0.63	0.80	0.81	0.69	0.34	0.16	0.64	0.98	1.71
5	Procedural control	6.76	30.67	62.93	73.72	79.85	85.38	89.52	89.64	90.76	91.74	98.51
6	Toxicity control	1.87	13.13	29.44	34.57	37.35	41.22	43.02	43.71	45.09	47.67	51.75

Results were calculated using the actual analytical (unrounded) results and not the rounded values presented in this table. All values were corrected for mean inoculum blank CO2 production.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

ref substance degradation >60% by 14d (89.52%), <5% inorganic C in medium at test start (4.72%), diff in test substance degradation <20% (0.62% 14d, 7.08% 28d), CO2 evol in controls ≤40 mg/L (17.50 mg/L)

Interpretation of results:

not readily biodegradable

Conclusions:

DiBrORMA was 3.69% biodegraded in a 28-day OECD 301B test.

Executive summary:

Ready biodegradability of DiBrORMA was assessed according to OECD 301B guidelines. Duplicate flasks were used for blanks and the test substance, with single flasks for procedural control (sodium benzoate), and toxicity control samples. The reference substance was degraded adequately by day 7. The toxicity control was biodegraded 43.02 % by day 14. The test substance was biodegraded (3.69%) by day 28. Thus, DiBrORMA is not considered readily biodegradable but is not inhibitory to biodegradation.

The test was conducted according to internationally accept guidelines and is GLP compliant. It is reliable without restrictions and is suitable for Risk Assessment, Classification & Labelling, and PBT Analysis.