Esterification product of sunflower-oil fatty acids, with 1,4:3,6-dianhydro-D-glucitol

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From January 25, 2018 to April 24, 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

GLP

Qualifier:

according to guideline

Guideline:

EU Method C.4-D (Determination of the "Ready" Biodegradability - Manometric Respirometry Test)

Version / remarks:

May 30, 2008

Deviations:

yes

Remarks:

deviations from the recommended temperature (during < 2 hours). No impact suspected on the study.

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

Adopted July 17, 1992.

Deviations:

yes

Remarks:

deviations from the recommended temperature (during < 2 hours). No impact suspected on the study.

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): Aerobic activated sludge, microorganisms from a domestic waste water treatment plant was supplied by the sewage treatment plant Rossdorf, Germany
- Pretreatment : 3 times, the activated sludge was washed by centrifugation and the supernatant liquid phase was decanted after 20 minutes of deposition. The solid material was re-suspended in test water and centrifuged again.
- Preparation of inoculum for exposure: An aliquot of the final sludge suspension was weighed, dried and the ratio of wet sludge to its dry weight was determined. Based on this ratio, calculated aliquots of washed sludge suspension, corresponding to 3.5 g dry material per litre were mixed with test water
- Concentration of sludge: 3.5 g dry material per litre
- Storage conditions : The final suspension was aerated overnight before its use in the experiment.

Duration of test (contact time):

<= 28 d

Initial conc.:

103.1 mg/L

Based on:

test mat.

Initial conc.:

279.8 mg/L

Based on:

ThOD

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: Analytical grade salts were added to pure water to prepare the following stock solutions:
a) 8.5 g KH2PO4, 21.75 g K2HPO4, 33.4 g Na2HPO4 x 2 H2O, 0.5 g NH4Cl filled up with pure water to 1000 mL volume; The pH-value was 7.4.
b) 11.25 g MgSO4 x 7 H2O filled up with pure water to 500 mL volume
c) 18.2 g CaCl2 x 2 H2O filled up with pure water to 500 mL volume
d) 0.125 g FeCl3 x 6 H2O filled up with pure water to 500 mL volume
In order to avoid precipitation of iron hydroxide in the stock solution d), one drop of concentrated HCl per litre was added before storage.
50 mL of stock solution a) and 5 mL of the stock solutions b) to d) were combined and filled up to a final volume of 5000 mL with pure water. The pH of the test water was set to 7.4 from 6.4 with Sodium hydroxide
- Test temperature: 22°C ± 1°C
- pH: 7.4 ± 0.2
- pH adjusted : yes
- CEC (meq/100 g): not reported
- Aeration of dilution water : continuous stirring
- Suspended solids concentration : 3.5 g/L sludge stock suspension and final concentration in the tested flasks is 28.7 mg sludge/L
- Continuous darkness: yes
The amounts of test item and reference item were directly weighed into the test flasks.


TEST SYSTEM
- Culturing apparatus: Manometric Test System with test flasks containing a volume of approximately 500 mL.
- Number of culture flasks/concentration: 2 test flasks
- Method used to create aerobic conditions: not reported
- Measuring equipment: BSB/BOD-Sensor-System, Aqualytic Dortmund, Germany
- Details of trap for CO2 : Potassium hydroxide solution (45%) was used for trapping the produced carbon dioxide.

SAMPLING
- Sampling method: daily measurements of pressure decrease

CONTROL AND BLANK SYSTEM
- Inoculum blank: 2 flasks
- test flask : 2 flasks
- Inoculum reference : 1 flask
- Abiotic sterile control: 1 flask
- Toxicity control: 1 flask

Reference substance:

benzoic acid, sodium salt

Remarks:

tested at the concentration of 102 mg/L, corresponding to 170 mg/L ThOD(NH4)

Test performance:

Climatised chamber : Temperature: 22°C ± 1°C
7.4 to 7.5 (measured at the start of the test)
7.2 to 7.6 (measured at the end of the test)

Key result

Parameter:

% degradation (O2 consumption)

Value:

68

Sampling time:

28 d

Remarks on result:

other: The tested substance is considered readily biodegradable because it is an UVCB and > 60% biodegradation is reached in 28 days, although failing the 10 day window.

Details on results:

In the toxicity control containing both, the test item and the reference item sodium benzoate, 48% (ThODNH4) biodegradation was noted within 14 days and 60% (ThODNH4) biodegradation after 28 days of incubation. The test item is not considered as inhibitory to the aerobic activated sludge microorganisms because degradation was >25% within 14 days.

Results with reference substance:

The reference item sodium benzoate was sufficiently degraded to 79% after 14 days and to 84% after 28 days of incubation, thus confirming the suitability of the aerobic activated sludge inoculum used.

  Cumulative Biochemical Oxygen Demand (mg O₂/L) in Test Flasks during the Test Period of 28 Days

 

Time	Flask No.
(days)	1	2	3	4	5	6	7
1	5	20	5	5	55	0	75
2	15	45	5	5	95	0	105
3	30	55	10	10	100	0	120
4	50	70	10	10	115	0	140
5	70	85	10	15	125	0	160
6	85	95	15	15	130	0	170
7	100	105	15	15	135	0	180
8	110	115	15	15	140	0	190
9	120	120	15	15	145	0	195
10	130	125	15	15	145	5	205
11	135	135	15	15	150	10	210
12	145	135	15	15	150	20	215
13	150	140	15	15	150	35	220
14	160	145	15	15	150	45	230
15	165	150	15	15	155	50	235
16	170	155	15	15	155	55	240
17	175	160	15	15	155	60	245
18	180	165	15	15	155	60	255
19	185	165	15	15	160	65	265
20	190	170	15	15	160	70	270
21	195	170	15	15	160	70	275
22	200	175	15	20	160	70	280
23	205	175	15	20	160	75	280
24	210	180	15	20	160	75	280
25	210	180	15	20	160	80	280
26	215	185	15	20	160	80	285
27	220	185	15	20	160	85	285
28	225	190	15	20	160	85	285

 Flasks 1 and 2: LAB 4448

 Flasks 3 and 4: inoculum control

Flask5: reference(procedure control)

 Flask 6: abiotic control

 Flask 7: toxicity control

 

 

Percentage Biodegradation of Test Item, of Sodium Benzoate and of the Toxicity Control

based on ThODNH4

Time	Percentage Biodegradation^1
(Days)	LAB 4448^1		Sodium Benzoate^2	Toxicity control^1, 2
	Flask 1 [%]	Flask 2 [%]	Flask 5 [%]	Flask 7 [%]
1	0	5	29	16
2	4	14	53	22
3	7	16	53	25
4	14	21	62	29
5	21	26	66	33
6	25	29	68	35
7	30	32	71	37
8	34	36	74	39
9	37	38	76	40
10	41	39	76	43
11	43	43	79	44
12	46	43	79	45
13	48	45	79	46
14	52	47	79	48
15	53	48	82	49
16	55	50	82	50
17	57	52	82	52
18	59	54	82	54
19	61	54	85	56
20	62	55	85	57
21	64	55	85	58
22	65	56	84	59
23	67	56	84	59
24	69	58	84	59
25	69	58	84	59
26	70	60	84	60
27	72	60	84	60
28	74	62	84	60

                   ¹ThOD_NH4of LAB 4448: 2.715 mg O₂/mg test item
                   ²ThOD_NH4of sodium benzoate: 1.666 mg O₂/mg reference item

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable, but failing 10-day window

Remarks:

Since the substance is an UVCB and it reach > 60% in 28 days, it is considered as readily bioderadable.

Conclusions:

The tested substance "LAB 4448" demonstrated 68% biodegradation in OECD 301F test and it is considered as readily biodegradable.

Executive summary:

The substance LAB 4448 was tested for its ready biodegradation according the EU Method C.4 -D and OECD Guideline 301F, and in compliance with the GLP.

The biodegradation was followed through the oxygen consumption measured by the pressure changes in the tested flasks, and the CO2 emitted is absorbed by a solution of potassium hydroxyde. The inoculum is prepared from activated sludge coming from a domestic wastewater treatment plant. The concentration of the inoculum is 28.7 mg sludge per liter. The substance LAB 4448 is tested in two replicates at the concentration of 103.1 mg/L, corresponding to 279.8 mg/L (ThOD(NH4)). Two replicates of blank control containing only the inoculum, one flask of the reference control, and one flask of the toxicity control (with the tested and the reference substances) were also tested in parallel.

All the validity criteria were fullfilled. The reference substance, sodium benzoate, was sufficiently degraded to 79% after 14 days, thus confirming the suitability of the aerobic activated sludge inoculum. No toxicity was observed in the toxicity control.

The mean biodegradation of LAB 4448 at the end of the test was 68% (ThODNH4). The 10-Day window criteria was not passed. However since the LAB 4448 substance is an UVCB with carbon chains of different lengths, this criteria has not to be fullfilled and LAB 4448 is considered as readily biodegradable.

This biodegradation study is acceptable, and satisfies the requirements of the Method C.4-D and OECD Guideline 301F.

Description of key information

The tested substance "LAB 4448" demonstrated 68% biodegradation in OECD 301F test and it is considered as readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

The substance LAB 4448 was tested for its ready biodegradation according the EU Method C.4 -D and OECD Guideline 301F, and in compliance with the GLP.

The biodegradation was followed through the oxygen consumption measured by the pressure changes in the tested flasks, and the CO2 emitted is absorbed by a solution of potassium hydroxyde. The inoculum is prepared from activated sludge coming from a domestic wastewater treatment plant. The concentration of the inoculum is 28.7 mg sludge per liter. The substance LAB 4448 is tested in two replicates at the concentration of 103.1 mg/L, corresponding to 279.8 mg/L (ThOD(NH4)). Two replicates of blank control containing only the inoculum, one flask of the reference control, and one flask of the toxicity control (with the tested and the reference substances) were also tested in parallel.

All the validity criteria were fullfilled. The reference substance, sodium benzoate, was sufficiently degraded to 79% after 14 days, thus confirming the suitability of the aerobic activated sludge inoculum. No toxicity was observed in the toxicity control.

The mean biodegradation of LAB 4448 at the end of the test was 68% (ThODNH4). The 10-Day window criteria was not passed. However since the LAB 4448 substance is an UVCB with carbon chains of different lengths, this criteria has not to be fullfilled and LAB 4448 is considered as readily biodegradable.

[Type of water: freshwater]