1H-Imidazolium, 3-ethyl-1-methyl-, tetrafluoroborate(1-) (1:1)

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:

experimental starting date: 2015-02-25; experimental completion date: 2015-03-26

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Report date:

2015

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 310 (Ready Biodegradability - CO2 in Sealed Vessels (Headspace Test)

Version / remarks:

resp. ISO 14593:2500 resp. EU C.29

Deviations:

yes

Remarks:

Temperature range was 19.5 – 21.2 °C instead of 20 ± 1 °C. This is considered as uncritical concerning the outcome of the study

GLP compliance:

yes (incl. QA statement)

Remarks:

Landesamt für Umwelt, Wasserwirtschaft und Gewerbeaufsicht; Kaiser-Friedrich-Straße 7, D-55116 Mainz

Test material

Test material information

Constituent 1

Reference substance name:

17PI120_1

IUPAC Name:

17PI120_1

Test material form:

other: viscous liqid

Details on test material:

Stabilized EMIM BF4:
Appearance: lightly yellow clear viscous liquid
Purity: 93.36% (EMIM+, HPLC), 86.86% (BF4-, titration), 4.89% (Stabilizer, HPLC)

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

Specification: Activated sludge from a biologic sewage treatment plant - mostly household sewage.
Source: activation basin, Stadtentsorgung Neustadt, Im Altenschemel, NW-Lachen-Speyerdorf
Date of collection: 26. Feb. 2015, batch no.: 20150226
Pre-Treatment: The sludge eas filtrated through a cloth, washed with tap water twice and with test medium once. The solids were the resuspended in
test medium and aerated. The dry matter was determined with 3720 mg suspended solids /L.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

53.1 mg/L

Based on:

DOC

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

inorg. C analysis

Details on study design:

This study was performed in order to evaluate the aerobe degradation potential of stabilized EMIM BF4 by aerobe micro-organisms at a given concentration.
The test item as the sole source of carbon and energy was incubated in a buffer-mineral salts medium which was inoculated with a mixed population of micro-organisms. The test was performed in sealed bottles with a headspace of air, which provides a reservoir of oxygen for aerobic biodegradation. The CO2 evolution resulting from the readily aerobic biodegradation of the test item was determined by measuring the IC produced in the test bottles in excess of that produced in blank control vessels containing inoculated medium only. The extent of biodegradation was expressed as a percentage of the theoretical maximum IC production (ThIC), based on the quantity of test item (as organic carbon) added initially.

Reference substance

Reference substance:

aniline

Remarks:

TOC = 1651 mg/L (stock solution)

Results and discussion

% Degradation

Parameter:

% degradation (inorg. C analysis)

Value:

1.8

Sampling time:

28 d

BOD5 / COD results

Results with reference substance:

28 d 83.3 % degradation

Any other information on results incl. tables

Degradation table (degradation values in %):

Day	Pos. Control 1	Pos. Control 2	Pos. Control Mean	Test 1	Test 2	Test Mean	Abiotic Control	Toxicity Control
0	3.5	-1.9	0.8	-0.2	0.7	0.3	-0.8	-0.9
4	56.1	56.3	56.2	-2.3	1.8	-0.3	1.8	28.2
8	67.3	69.3	68.3	-0.8	-2.3	-1.6	2.4	33.6
12	80.4	82.9	81.7	3.9	3.8	3.9	1.8	42.1
15	79.7	82.6	81.1	2.8	1.5	2.2	7.7	42.1
21	82.7	83.5	83.1	-4.9	-2.3	-3.6	3.4	45.4
26	73.3	77.5	75.4	-3.8	-2.2	-3.0	1.1	38.5
28	82.5	84.0	83.3	1.6	1.9	1.8	5.2	42.9

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

The test item must be classified as "not readily biodegradeable"

Executive summary:

The test item was tested using a concentration of 53.1 mg stabilized EMIM BF4/L in test medium following ISO 14593:205.

Aniline was chosen as positive control.

Activated sludge from a sewage treating plant was used as inoculum (concentration: 4 mg suspended solids/L). The test was left running for 28 days.

All validity criteria were met. Degradation of the positive control was 68 % after eight days.

The following data were determined for the test item stabilized EMIM BF4:

10 -day-window: not detectable

degradation at the end of the test: 1.8 %

Therefore, stabilized EMIM BF4 is not readily biodegradeable following OECD 310.