[No public or meaningful name is available]

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:

21 November 2019 - 19 December 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 F (Ready Biodegradability: Manometric Respirometry Test)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Reaction mass of 1,10-decanediol dimethacrylate (CAS 6701-13-9) and 10-methacryloyl-oxy-decylphosphate

Molecular formula:

C18H30O4 and C14H27O6P

IUPAC Name:

Reaction mass of 1,10-decanediol dimethacrylate (CAS 6701-13-9) and 10-methacryloyl-oxy-decylphosphate

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
Product identification number: LE-F100-0804-6, 41-8650-3115-I 4010025452
Purity: Not available

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Stored at room temperature (15-25°C) in a ventilated cabinet, away from heat, acids, bases and amine in a container tightly closed.

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): Rouen system wastewater treatment plant from Rouen conurbation, 29 Rue de l'ancienne Mare, 76140 Le Grand-Quevilly. Plant treats 80000 m3 of water per day with a capacity for a population of 550000.
- Storage conditions: Stored at room temperature with air supply until test. Sludge was not fed.
- Storage length: Collected on 25 October 2019, test started on 21 November 2019 (28 days).
- Concentration of sludge: 3.28 g/L at the time of collection (info from WWTP).

Duration of test (contact time):

ca. 28 d

Initial test substance concentration

Initial test substance concentration 1

Initial conc.:

ca. 100 mg/L

Based on:

test mat.

Initial test substance concentration 2

Initial conc.:

ca. 230 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: Standard OECD 301F test medium with a substitution of sodium phosphate anhydride (266.4 mg/L).
- Additional substrate: none
- Solubilizing agent: None. Test substance was weighed and added directly to test vessels.
- Test temperature: 22°C
- pH: 7.5
- pH adjusted: No
- Suspended solids concentration: ca. 30 mg/L
- Continuous darkness: yes

TEST SYSTEM
- Culturing apparatus: 610 mL glass flasks closed off with a manometric cap device.
- Number of culture flasks/concentration: two
- Method used to create aerobic conditions: continuous stirring
- Measuring equipment: OXITOP OC 110 Controller
- Test performed in closed vessels due to significant volatility of test substance: Yes
- Test performed in open system: no
- Details of trap for CO2 and volatile organics if used: CO2 traps with NaOH pellets were placed in each flask.

CONTROL AND BLANK SYSTEM
- Inoculum blank: duplicate
- Abiotic sterile control: one flask with test media, test item, and sterilizing agent (mercuric chloride, 0.04 g/L) as biocide
- Toxicity control: one flask with inoculum, test item and reference item (100 mg/L).

Reference substance

Reference substance:

benzoic acid, sodium salt

Remarks:

100 mg/L

Results and discussion

% Degradation

Key result

Parameter:

% degradation (O2 consumption)

Value:

ca. 77 - ca. 80

Sampling time:

28 d

Details on results:

Oxygen ulitlization in the inoculum blanks were 12 and 13 mg/L by day 28
Detailed results on oxygen utilization of test substance are provided in Table 1 and are graphically depicted in the illustration.
Detailed results on oxygen utilization by the reference substance and in the toxicity control are provided in Table 2.
Detailed results on oxygen utilization in the abiotic control are provided in Table 2. The abiotic control showed showed no oxygen utilization throughout the experiment.
The reference substance was 85.4% degraded by day 7 and 92.7% degraded by day 14 (Table 2). Biodegradation in the toxicity control (Table 2) was 58.2% by day 7 and 71.9% by day 14. Therefore, MDP is not toxic to activated sludge.

Any other information on results incl. tables

Table 1. Percent of biodegradation for the test substance

Time (days)	Test item solution 1 (% biodegradation rate)	Test item solution 2 (% biodegradation rate)	Absolute difference (% biodegradation rate)
0	0.0	0.0	-
1	2.5	0.0	2.5
2	2.0	0.4	1.6
3	11.9	16.4	4.5
4	18.5	22.3	3.8
5	23.4	27.3	3.9
7	31.3	36.2	4.9
10	41.9	50.4	8.5
14	52.3	60.2	7.8
21	66.1	72.9	6.8
28	76.9	80.4	3.6

Table 2.Percent of biodegradation in control conditions

Time (days)	Reference control (% biodegradation rate)	Toxicity control (% biodegradation rate)	Abiotic control (% biodegradation rate)
0	0.0	0.0	0
1	5.60	0.50	< 0
2	56.7	28.9	< 0
3	72.3	41.0	< 0
4	79.5	48.8	< 0
5	78.9	52.7	< 0
7	85.4	58.2	< 0
10	89.7	64.4	< 0
14	92.7	71.9	< 0
21	95.0	81.6	< 0
28	97.4	86.2	< 0

 

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

difference in test substance degradation <20% (2.1%), ref substance degradation >60% by day 14 (day 3), toxicity control degradation >25% by day 14 (71.9%), oxygen uptake by inoculum blanks <60 mg/L in 28 days (12-13 mg/L), pH within range 6-8.5 (pH 7.5).

Interpretation of results:

readily biodegradable

Conclusions:

MDP was 77-80% biodegraded in a 28-day OECD 301F test.

Executive summary:

Ready biodegradability of MDP was assessed according to OECD 301F. Duplicate flasks were used for blanks and the test substance, with single flasks for reference substance (sodium benzoate), toxicity control, and abiotic (mercuric chloride-killed) samples. The reference substance was degraded adequately by day 3. The test substance was biodegraded (77-80%) by day 28. Degradation was >10% on day 3 but did not exceed 60% by day 13, thus failing the 10-day window criteria. However, the test material a multiconstituent substance consisting of methacrylate and/or phosphate esters of 1,10-decanediol. The differing constituents are expected to have similar although not necessarily identical availability and degradation profiles. As such, the 10-day window concept is not directly applicable to this test.. The toxicity control was biodegraded 71.9% by day 14 and 86.2% by day 28. 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.