3-methyl-1-vinyl-1H-imidazolium chloride

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:

19 Feb 2015 to 25 Mar 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Report date:

2015

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.4-C (Determination of the "Ready" Biodegradability - Carbon Dioxide Evolution Test)

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 835.3110 (Ready Biodegradability)

Test guideline 4

Qualifier:

according to guideline

Guideline:

other: ISO 9439 Water Quality - Evaluation in an aqueous medium of the "ultimate" aerobic biodegradability of organic compounds - Method by analysis of released carbon dioxide.

GLP compliance:

yes (incl. QA statement)

Remarks:

BASF SE, Experimental Toxicology and Ecology, 67056 Ludwigshafen, Germany.

Test material

Test material information

Constituent 1

Reference substance name:

3-methyl-1-vinyl-1H-imidazolium chloride

EC Number:

236-752-3

EC Name:

3-methyl-1-vinyl-1H-imidazolium chloride

Cas Number:

13474-25-4

Molecular formula:

C6H9N2.Cl

IUPAC Name:

1-ethenyl-3-methyl-2,3-dihydro-1H-imidazol-1-ium chloride

Specific details on test material used for the study:

- Name of the test material (as cited in study report): 3-Methyl-1-vinyl-1H-imidazolium chloride
- Test substance No.: 14/0365-1
- Batch identification: Mischprobe B 407 / 408 vom 23.08.14, 14001329T0 - 14001629T0
- Identity: Confirmed by several spectroscopic methods
- Purity: 97.7 area-% (203 nm) and 98.2 area-% (220 nm), HPLC Fingerprint and identification of constituents by MS. Main component: 58.3g/100g.
- Homogeneity: Homogeneous
- Date of production: August 2014
- Physical state / apperance: liquid, brownish yellow, clear
- Expiry date: August 2015.
- Storage conditions: room temperature

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

Activated sludge from municipal waste water treatment plant Mannheim, Germany. The inoculum was collected on 20 February 2015 from the aeration tank of the plant. A suitable aliquot of the activated sludge suspension was sieved by a finely woven mesh with a mesh size about 1 mm. To reduce the content of inorganic carbon in the blank controls the activated sludge was aerated with carbon dioxide free air for about 96 hours at 22 ± 2° C. At the day of exposure the suspension was washed one time with drinking water. Therefore the aeration was stopped and the sludge was allowed to settle. After settling the supernatant was discarded and the remaining sludge suspension was filled up with drinking water and the concentration oft the sludge was adjusted to 6.0 g/L dry weight.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial test substance concentration 1

Initial conc.:

25.6 mg/L

Based on:

test mat.

Initial test substance concentration 2

Initial conc.:

7.5 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 mineral medium: Guideline solutions A-D, dissolved in 1 L water.
1. Solution A: KH2PO4: 8.50 g; K2HPO4: 21.75 g; Na2HPO4 × 2 H2O: 33.40 g; NH4Cl: 0.50 g
2. Solubiton B: CaCl2 × 2 H2O: 36.40 g
3. Solution C: MgSO4 × 7 H2O: 22.50 g
4. Solution D: FeCl3 × 6 H2O: 0.25 g
- Test temperature: 22 ± 2° C
- pH: adjusted to 7.4 ± 0.2 if necessary; pH-values at the end of exposure were 7.0 - 7.2
- Continuous darkness: no
- Stirring: incubation bottles were stirred on magnetic stirrers;
- Aeration: Yes, performed with carbon dioxide free air at a flow of approximately 800 mL per hour

PREPARATION
- Addition of medium: 15 mL solution A, 1.5 mL solution B, 1.5 mL solution C and 1.5 mL solution D
- Preparation of test vessels: required amounts of the test substance aliquots for the scheduled test concentration of 7.5 mg/L TOC were weight onto small glass plates (microscope cover slips) and completely added with the glass plates to the vessels of test substance assays and to the vessel of inhibition control. These vessels were stirred for about 30 minutes to ensure the dissolving of the test substance in the mineral medium. Finally enough reference substance stock solution was added to reach 20 mg TOC/L in the reference substance assay and 7.5 mg TOC/L in the inhibition control.
- Addition of sludge: Aliquots of activated sludge suspension were added to the test vessels to obtain an activated sludge concentration of 30 mg/L dry weight.

TEST SYSTEM
The Carbon Dioxide Evolution Test was performed in 2 L incubation bottles filled up to a volume of 1.5 L. The bottles were connected to two serial scrubbing bottles (total volume 250 mL) filled with 100 mL 0.05 mol sodium hydroxide solution for the adsorption of carbon dioxide from biodegradation processes. The TIC-value of the freshly prepared sodium hydroxide solution was determined and considered by the calculation of biogenic produced carbon dioxide amount.

SAMPLING
- TIC: Usually twice a week the Total Inorganic Carbon (TIC) values of the adsorption solutions of the first trap were determined and used for the calculation of the produced carbon dioxide. After each sampling the second trap was moved forward and the new trap with fresh sodium hydroxide solution was placed into the second position. Each trap was analyzed separately. At the begin and at the end of exposure, dissolved organic carbon (DOC) samples were taken from the test vessels of the blank control and the reference substance control.
- DOC: For determination of the decrease of dissolved organic carbon (DOC) samples were taken from the test vessels of the blank control and from the test vessel of the reference substance control and the DOC content was determined after centrifugation (approx. 15 minutes at 4000 rpm). See 'Any other information on materials and methods incl. tables' as to why no DOC measurements from the test assays were performed.
- pH: At the end of exposure, the pH values were measured in each test vessel.

CONTROL AND BLANK SYSTEM
- 2 blank control assays
- 1 inhibition control test assay
- 1 reference substance assay

Reference substance

Reference substance:

aniline

Remarks:

TOC concentration of the ref. substance: 20 mg/L(nominal value)

Results and discussion

Test performance:

- Amount of produced CO2 in the blank controls at the end of exposure (mean value): 39.1 mg/L
- Deviation of the degree of biodegradation of the test substance in the plateau phase should was <20%
- The degree of biodegradation of the reference substance was >60% CO2/ThCO2 after 14 days
- The degree of biodegradation in the inhibition control was >25% CO2/ThCO2 after 14 days
- The amount of produced CO2 in the inoculum blank (“blank controls”) at the end of exposure (mean value) was <70 mg/L

% Degradation

Key result

Parameter:

% degradation (CO2 evolution)

Value:

>= 20 - <= 30

Sampling time:

28 d

Details on results:

Duration of the adaptation phase was 23 days. The biodegradation was 23% CO2/ThCO2 (mean value) at day 28. The required pass level of 60% for ready biodegradability within a ten days window was thus not reached. For more details, see ‘Any other information on results incl. tables’.

BOD5 / COD results

Results with reference substance:

The biodegradation of the reference substance after 14 days was 68% (CO2/ThCO2).

Any other information on results incl. tables

Table: degree of biodegradation [% Co2/ThCO2]

Test duration [days]	RS	IH	TS1	TS2	TS mv
0	0	0	0	0	0
1	0	0	-1	2	1
3	1	2	-5	5	0
6	14	14	-9	7	-1
10	50	22	-13	11	-1
14	68	27	0	15	8
17	78	26	1	4	3
20	85	28	-11	4	-4
22	89	32	9	6	8
27	98	41	22	16	19
28	101	47	24	22	23

RS: reference substance assay

IH: inhibition control assay

TS: test substance assay

mv: mean value

Table: Measured data of total inorganic carbon TIC [mg/L]

Day		BC NaOH	BC1	BC2	RS	IH	TS1	TS2
0	a	0.7	-	-	-	-	-	-
	b	0.9	-	-	-	-	-	-
1	a	0.7	4.9	3.1	5.3	4.5	2.6	6.3
	b	0.6	5	3.3	5.4	4.5	2.7	6.4
3	a	1	10.2	7.2	10.8	13.6	4.7	11.8
	b	0.9	10	7.2	10.7	13.8	4.2	11.8
6	a	0.5	19.3	15.4	56.7	44.2	12.3	20.3
	b	0.6	19.2	15.1	56.9	44.1	12.3	20.4
10	a	0.9	21.1	12.2	122	34.6	12.8	21
	b	0.9	21	12.4	124	34	12.9	21.2
14	a	0.8	19.4	22.5	76.5	32.7	34.4	26
	b	0.7	19.2	22.4	77.1	32.8	35.8	25.9
17	a	0.7	23.9	33.4	58.1	26.1	30.7	15.5
	b	0.7	24.1	33.5	58	25.9	30.7	16
20	a	0.6	22.8	20.1	42.5	27	6.9	21.4
	b	0.6	23.1	20.3	42.5	26.4	7.2	21.5
22	a	0.5	11	10.9	21.9	20	34	12.9
	b	0.4	11	11	21.6	19.5	33.6	13.2
27	a	0.7	15.9	12.7	40.6	33.7	28.8	26.4
	b	0.8	15.5	12.9	40.9	33.6	28.4	26.4
28	a	0.5	6.4	6.2	13	10.3	7.9	8.7
	b	0.6	6.4	6.1	12.5	10.4	8	8.7
flask 1 29	a	-	15.6	14.3	18.4	23.1	16.6	18.8
	b	-	15.5	14.1	18.6	23	16.3	18.9
flask 2 29	a	-	4.2	3.5	4.3	4.7	3.4	3.3
	b	-	4.2	3.5	4.1	4.7	3.4	3.4

The NaOH blank value is determined on filling the absorption vessels.

The measured values, for instance applies on day 0 for the first and the second sampling.

The NaOH blank value was subtracted from each test vessel.

a/b = single values of TIC-measurement

Table: Produced carbon dioxide amount in the test vessels

[mg CO2/test vessel]						mg CO2 added up after subtraction of the mean value of the blank controls.
Duration of exposure [days]	BC mv	RS	IH	TS1	TS2	RS	IH	TS1	TS2
1	1.2	1.7	1.4	0.7	2	0.5	0.2	-0.5	0.8
3	2.9	3.7	4.7	1.3	4	1.3	2	-2.1	1.9
6	6.1	20.6	16	4.3	7.2	15.8	11.9	-3.9	3
10	5.8	44.9	12.2	4.4	7.4	54.9	18.3	-5.3	4.6
14	7.5	28	11.8	12.7	9.3	75.4	22.6	-0.1	6.4
17	10.2	21	9.2	10.9	5.4	86.2	21.6	0.6	1.6
20	7.6	15.3	9.5	2.3	7.6	93.9	23.5	-4.7	1.6
22	3.8	7.7	7	12.1	4.5	97.8	26.7	3.6	2.3
27	5	14.7	12.1	10.3	9.5	107.5	33.8	8.9	6.8
28	2.1	4.5	3.6	2.8	3	111.4	38.6	10	9
29	6.4	7.9	9.7	6.8	7.7

Table: Measurement of Dissolved Organic Carbon

		[mg/L DOC]
		BC1	BC2	BC mv	RS	IH	TS1	TS2	TS mv
At begin of exposure	a	0.3	0.4	0.3	19.9	-	-	-
	b	0.3	0.3		19.9	-	-	-
At the end of exposure	a	1.7	1.3	1.6	1.5	-	-	-
	b	1.8	1.6		1.6	-	-	-
Degradation of DOC [%]					101	-	-	-	-

INHIBITION CONTROL

The degree of biodegradation in the inhibition control after 14 days was 27% CO2/ThCO2.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

see 'Test performance'

Interpretation of results:

not readily biodegradable