1-Propanaminium, 2-hydroxy-N-(2-hydroxyethyl)-N-methyl-N-[2-[(1-oxo-9-octadecen-1-yl)amino]ethyl]-3-sulfo-, methyl sulfate, sodium salt (1:1:1)

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:

July - August 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of activated sludge: Collected from the aeration tank of a sewage treatment plant unit treating predominantly domestic sewage at Siddaganga Institute of Technology, Chandana complex, Tumkur – 572103, India
- Pretreatment: A well-mixed, measured volume of an activated sludge was filtered through a pre-weighed crucible. The crucible was heated to constant mass at 105ºC for 3 hours 14 minutes and then weighed.
- Preparation: Accurately 23.6 mL of the inoculum was added to each of the flasks to attain a concentration of 30 mg/L of suspended solids.

Duration of test (contact time):

28 d

Initial conc.:

15 mg/L

Based on:

TOC

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium: The dilution water was prepared by adding 1 mL of each of four salt solutions to 500 mL of deionised water. This solution was diluted to 1000 mL and mixed well.
- Additional substrate: No
- pH adjusted: No
- Aeration of dilution water: Aeration was applied for 1 hour at 20 ± 2°C.
- Continuous darkness: Yes
- Temperature: 22 ± 2°C

TEST SYSTEM
- Culturing apparatus: Incubator
- Number of culture flasks/concentration: 3
- Method used to create aerobic conditions: Aeration of dilution water for 1 hour

SAMPLING
- Sampling frequency: After 0, 3, 6, 9, 14, 19, 25 and 28 d
- Sample storage before analysis: No

CONTROL AND BLANK SYSTEM
- Inoculum blank: 2 bottles
- Toxicity control: 2 bottles

Reference substance:

acetic acid, sodium salt

Test performance:

The test item reached a maximum mean biodegradation value of 80.26% (% of ThCO2) for two bottles within 28 days exceeding the criterium of 60% biodegradation given by the guideline. The differences in replicate values of the removal of the test substance at the end of the test were less than 20% (i.e.1.49%).

Key result

Parameter:

% degradation (CO2 evolution)

Value:

80.26

Sampling time:

28 d

Details on results:

The total CO2 evolution in the control blanks at the end of the test was 1.98 mg/L which is less than 40 mg/L of validity criteria. The CO2 absorber traps were titrated on 29th day after acidifying the test flasks on 28th day. This acidification drives off any dissolved CO2 present in the test vessels. The results of the 0.05N HCl consumed for all the test flasks from the absorber vessels on Day 29 showed no significant change in all test flasks compared with the blank BaOH2 and confirmed that no significant production of CO2 into the absorber vessels occurred after acidifying the test flasks. All the criteria for acceptability of the test were met. Hence, the present study was considered to be valid.

Results with reference substance:

The percentage degradation of the procedure control substance (Sodium acetate) attained 62.91% (% of ThCO2) biodegradation by 14 days (greater than 60% degradation).

TABLE 1: PERCENTAGE OF DEGRADATION (% ThCO2)

Flask Content	Flask No.	Conc. of TOC in mg per litre	Percentage of Degradation (% ThCO2)
			Day 3	Day 6	Day 9	Day 14	Day 19	Day 25	Day 28
Reference substance- Sodium acetate	3	15	11.32	18.72	40.20	63.41	74.50	84.39	92.98
	4		11.12	18.12	39.40	62.41	74.17	83.59	91.92
	Mean		11.22	18.42	39.80	62.91	74.33	83.99	92.45
	Difference Between the Replicates 3 and 4								-1.07
	Percentage Difference								-1.15
Test Item- LYAF	5	15	3.00	5.59	21.61	39.63	54.45	66.27	79.66
	6		3.66	6.79	22.75	40.63	55.18	67.34	80.86
	Mean		3.33	6.19	22.18	40.13	54.82	66.81	80.26
	Difference Between the Replicates 5 and 6								1.20
	Percentage Difference								1.49

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

The results of the CO2 Evolution Test indicated that the test item is readily biodegradable by OECD criteria. The test item was readily biodegradable within a 10-days window and after 28 days (80.26% of ThCO2).

Executive summary:

To assess the ready biodegradability of the test item a GLP-compliant CO2 Evolution Test (Modified Sturm Test) according to OECD TG No. 301 B (adopted 17th July 1992) was carried out. During the study, the amount (mg) of CO2 produced was calculated at the start of the experiment on day 0, 3, 6, 9, 14, 19, 25, 28 and 29 respectively. The relative biodegradation values were calculated from the CO2 measurements during the test period of 28 days. The test item reached a maximum mean biodegradation value of 80.26 (% of ThCO2) for two bottles within 28 days which exceeded the criteria of 60% biodegradation. The differences in replicate values of the removal of the test substance at the end of the test were less than 20% (i.e. 1.49%). The percentage degradation of the procedure control substance (Sodium acetate) attained 62.91% (% of ThCO2) biodegradation after 14 days (greater than 60% degradation). The total CO2 evolution in the control blanks at the end of the test was 1.98 mg/L which is less than 40 mg/L of validity criteria. The CO2 absorber traps were titrated on 29th day after acidifying the test flasks on 28th day. This acidification drives off any dissolved CO2 present in the test vessels. The results of the 0.05N HCl consumed for all the test flasks from the absorber vessels on Day 29 showed no significant change in all test flasks compared with the blank BaOH2 and confirmed that no significant production of CO2 into the absorber vessels occurred after acidifying the test flasks. All the criteria for acceptability of the test were met. Hence, the present study was considered to be valid. The results of the CO2 Evolution Test indicated that the test item is readily biodegradable by OECD criteria. The test item was readily biodegradable within a 10-days window and after 28 days (80.26% of ThCO2) under the conditions of the CO2 Evolution test.

Description of key information

The results of the CO2 Evolution Test indicated that the test item is readily biodegradable by OECD criteria. The test item was readily biodegradable within a 10-days window and after 28 days (80.26% of ThCO2).

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

To assess the ready biodegradability of the test item a GLP-compliant CO2 Evolution Test (Modified Sturm Test) according to OECD TG No. 301 B (adopted 17th July 1992) was carried out. During the study, the amount (mg) of CO2 produced was calculated at the start of the experiment on day 0, 3, 6, 9, 14, 19, 25, 28 and 29 respectively. The relative biodegradation values were calculated from the CO2measurements during the test period of 28 days. The test item reached a maximum mean biodegradation value of 80.26 (% of ThCO2) for two bottles within 28 days which exceeded the criteria of 60% biodegradation. The differences in replicate values of the removal of the test substance at the end of the test were less than 20% (i.e. 1.49%). The percentage degradation of the procedure control substance (Sodium acetate) attained 62.91% (% of ThCO2) biodegradation after 14 days (greater than 60% degradation). The total CO2 evolution in the control blanks at the end of the test was 1.98 mg/L which is less than 40 mg/L of validity criteria. The CO2 absorber traps were titrated on 29th day after acidifying the test flasks on 28th day. This acidification drives off any dissolved CO2 present in the test vessels. The results of the 0.05N HCl consumed for all the test flasks from the absorber vessels on Day 29 showed no significant change in all test flasks compared with the blank BaOH2 and confirmed that no significant production of CO2 into the absorber vessels occurred after acidifying the test flasks. All the criteria for acceptability of the test were met. Hence, the present study was considered to be valid. The results of the CO2 Evolution Test indicated that the test item is readily biodegradable by OECD criteria. The test item was readily biodegradable within a 10-days window and after 28 days (80.26% of ThCO2) under the conditions of the CO2 Evolution test.