Spiro[piperidine-1,1'-pyrrolidinium] bifluoride

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:

2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

adopted July 1992

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

2008

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

Date of receipt : 2016-04-05
Expiry date : 2017-09-08

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

Type : mixed population of aquatic microorganisms (activated sludge)
Origin : aeration tank of a wastewater plant treating predominantly domestic sewage (Wupper area water authority, WWTP Odenthal)
Date of collection : 2016-12-12
Concentration of inoculum : 30 mg/L suspended solids
Pre-treatment of the inoculum
− Before use, the inoculum was stored for one day at room temperature under continuous stirring with aeration.
− The sludge was washed twice by adding mineral medium and centrifuging for 10 min at 2000 rpm and 20 °C and decanting off the supernatant.
− An aliquot of the wet sludge was dried in order to determine the wet weight / dry weight ratio of the sludge and to prepare a stock suspension (activated sludge) of 3 g dw/L.
− The calculated amount of sludge, needed to achieve 300 mL of this stock suspension, was dissolved in mineral medium and then filled up to a defined end volume.

Duration of test (contact time):

28 d

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Remarks:

BOD

Details on study design:

suspension of 100 mg/L test item in a mineral medium, equalling to 50-100 mg ThOD or COD/Litre as the nominal sole source of organic carbon, was stirred in a closed flask and inoculated at a constant temperature (22 ± 1 °C) for up to 28 days under aerobic conditions in the dark.
The consumption of oxygen (BOD) was determined by measuring the drop in pressure in the automated respirometer flasks. Evolved carbon dioxide was absorbed in sodium hydroxide. The amount of oxygen taken up by the test item (corrected for uptake by blank inoculum, run in parallel) was expressed as a percentage of chemical oxygen demand (COD).
The endogenous activity of the inoculum was checked running parallel blanks with inoculum but without test item. A reference compound (sodium benzoate) was run in parallel to check the operation of the procedures.
A toxicity control (test item and reference compound mixed, one replicate) was run in parallel, to ensure that the chosen concentration of the test item was not inhibitory to microorganisms.
Degradation was followed by the determination of oxygen uptake and measurements were taken at frequent intervals to allow the identification of the beginning and end of biodegradation and the slope of the biodegradation curve.
The test lasted for 28 days.
Because of the nature of biodegradation and of the mixed bacterial populations used as inoculum, determinations of test item and inoculum blank were carried out in triplicate and of reference compound in duplicate.
The oxygen uptake was calculated from the readings taken at regular and frequent intervals, using the method given by the manufacturer of the equipment. At the end of incubation, the pH was measured in the flasks.
The degradation rate of the test item was set in relation to its experimentally determined COD. As the COD implicitly covers the oxygen demand for the nitrification process, there was no need to take additional correction measures into account.

Reference substance:

benzoic acid, sodium salt

Key result

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

28 d

Remarks on result:

other: % degradation mean

Details on results:

Test concentration : 100 mg/L
Chemical oxygen demand : 2.375 mg O2/mg

Parameter:

BOD5

Value:

26.6 other: mg O2/L

Remarks on result:

other: mean value after 28 days

Results with reference substance:

Degradation of reference compound
% degradation mean after 28 days: 91
Test concentration : 100 mg/L
Theoretical oxygen demand : 1.665 mg O2/mg

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

RFR 6634 showed 0 % degradation after 28 days under aerobic conditions. Therefore, RFR 6634 is considered to be “Not Readily Biodegradable“.

Executive summary:

A study was performed to assess the ready biodegradability of RFR 6634.

The study was conducted in accordance with the Council Regulation (EC) No 440/2008, Method C.4-D “Manometric Respirometry Test“(2008). This test method is in all essential parts identical with OECD Guideline 301 F (adopted July 1992).

A suspension of RFR 6634 in a mineral medium was inoculated and incubated for 28 d under aerobic conditions. During this period, degradation was followed by continuous automated BOD determinations.

RFR 6634 showed:

0 % degradation after 7 days

0 % degradation after 14 days

0 % degradation after 21 days

0 % degradation after 28 days

Therefore, RFR 6634 is considered to be “Not Readily Biodegradable“.

The reference compound sodium benzoate showed 88 % degradation after 14 days.

Description of key information

A study was performed to assess the ready biodegradability of RFR 6634.

The study was conducted in accordance with the Council Regulation (EC) No 440/2008, Method C.4-D “Manometric Respirometry Test“(2008). This test method is in all essential parts identical with OECD Guideline 301 F (adopted July 1992).

A suspension of RFR 6634 in a mineral medium was inoculated and incubated for 28 d under aerobic conditions. During this period, degradation was followed by continuous automated BOD determinations.

RFR 6634 showed:

0 % degradation after 7 days

0 % degradation after 14 days

0 % degradation after 21 days

0 % degradation after 28 days

Therefore, RFR 6634 is considered to be “Not Readily Biodegradable“.

The reference compound sodium benzoate showed 88 % degradation after 14 days.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed