Trifluoromethanesulphonic anhydride

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 05 June 2012 to 22 nov 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.4-E (Determination of the "Ready" Biodegradability - Closed Bottle Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

11 april 2011

Oxygen conditions:

aerobic

Inoculum or test system:

sewage, industrial, adapted

Details on inoculum:

- Specification: Effluent from a biologic sewage treatment plant was used. The chosen plant is treating mostly household sewage.
- Source: The effluent was taken from the effluent channel of the sewage treatment plant, Edenkoben.
Date of collection: 19. Jun. 2012, batch no: 20120619.
- Pre-Treatment: The effluent was kept aerobic during transport and storage. Before usage, the effluent was left to settle for one hour. The effluent was aerated for five days at room temperature in order to lower the oxygen consumption of the blanks. 0.5 mL/L test medium were used.

Duration of test (contact time):

28 d

Initial conc.:

21.97 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium:
Stock solutions:
Solution A:
Potassium dihydrogenephosphate (KH2PO4): 8.5 g
Di-potassium hydrogenephosphate (K2HPO4): 21.75 g
Sodium di-hydrogenephosphate hydrate (NaH2PO4*H2O): 33.4 g
Ammonia chloride (NH4Cl): 0.5 g
H2O demin. ad: 1000 mL
The pH was adjusted to 7,4 +/- 0.1

Solution B:
Calcium chloride dihydrate (CaCl2*2H2O): 36.4 g
H2O demin. ad: 1000 mL

Solution C
Magnesium sulfate heptahydrate (MgSO4*7H2O): 22.5 g
H2O demin. ad: 1000 mL

Solution D
Iron(III) chloride hexahydrate (FeCl3*6H2O): 0.25 g
Di-sodium-ethylendiamintetraacetate dihydrate (Na2EDTA*2H2O): 0.4 g
H2O demin. ad : 1000 mL

The medium was freshly prepared.
Composition:
Solution A 1 mL
Solution B 1 mL
Solution C 1 mL
Solution D 1 mL
H2O demin. ad: 1000 mL

- Test temperature: 19.8 – 21.5°C
- Suspended solids concentration: 0.5 mL/L
- Continuous darkness: yes
- Other: After preparation, the medium was aerated for 50 hours. Then the medium was stored at room temperature for 20 hours without aeration. The O2-concentration was then determined with 8.63 mg/L at 21°C.

TEST SYSTEM
- Culturing apparatus: 250 mL narrow neck bottles with glass stoppers.
- Number of culture flasks/concentration: 2
- Method used to create aerobic conditions: The effluent was taken from the sewage treatment plant and was aerated for five days in order to lower the oxygen demand of the effluent.
- Measuring equipment: Oximeter 538 wtw (for oxygen)

SAMPLING
- Sampling frequency: For each test series, seven samplings were made (on days 0, 3, 7, 11, 18, 23 and 28). For each sampling, the oxygen content of two vessels of each test series was measured (one vessel on day 0).


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

Reference substance:

benzoic acid, sodium salt

Remarks:

3.61 mg/L

Key result

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

28 d

Details on results:

For the determination of the biological results, the data were evaluated without consideration of nitrification. Because neither test item nor positive control contains nitrogen, the O2-uptake caused by nitrification was not considered for the determination of the degradation.
• The test item Trifluoromethanesulfonic acid must be considered as “not readily biodegradable“.
• The degree of biodegradation was 0 % after 28 days
• A 10-day-window could not be detected.

Results with reference substance:

The positive control reached the pass level already on day 3.

Degradation without Consideration of Nitrification in %:

Day	Positive Control			Test Item			Toxicity Control
	1	2	Mean	1	2	Mean	1	2	Mean
3	68.5	67.5	68.0	-6.7	-6.6	-6.6	-7.3	-7.0	-7.2
7	78.4	80.6	79.5	-1.4	-1.0	-1.2	38.0	37.7	37.9
11	82.4	82.2	82.3	-1.1	-2.0	-1.6	36.5	36.2	36.3
18	77.7	80.7	79.2	-1.5	-2.0	-1.7	38.8	37.0	37.9
23	79.4	74.1	76.8	-7.2	-7.3	-7.2	29.7	31.0	30.4
28	83.3	81.3	82.3	-1.7	-0.9	-1.3	35.8	36.4	36.1

Negative degradation values are caused by measurement uncertainties resp. small differences between oxygen decrease in the controls and in the test flasks.

Validity criteria fulfilled:

yes

Remarks:

O2-consumption in the controls: =< 1.5 mg/L Lowest measured O2-concentration in the test vessels: >= 0.5 mg/L Difference within replicates: =< 20% Degradation of positive control > 60%: =< 14 days Degradation in the toxicity control on day 14: >= 25%

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

Trifluoromethanesulfonic acid is not readily biodegradable in the closed bottle test.

Executive summary:

The study was performed in order to evaluate the aerobic ultimate biodegradation potential of Trifluoromethanesulfonic acid in a test for ready biodegradability, according to the OECD 301D guideline and under GLP conditions.

This study used a test item concentration of 21.97 mg/L (corresponding to a theoretical oxygen consumption of 5.86 mg/L).

The solution of the test item in mineral medium was inoculated with a relatively small number of micro-organisms from a mixed population and kept in completely full, closed bottles in the dark at constant temperature.

Degradation was followed by analysis of dissolved oxygen over a 28-day period. The amount of oxygen taken up by the microbial population during biodegradation of the test item, corrected for uptake by the blank inoculum run in parallel, is expressed as a percentage of COD.

There was 0% of degradation of test item after 28 days. The positive control reached the pass level already on day 3.As degradation in the toxicity flask was more than 25 % at the end of the test, the test item can be stated as not toxic towards the inoculum in a concentration of 11.72 mg/L

In these test conditions, Trifluoromethanesulfonic acid was not readily biodegradable.

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

The read-across justification is provided in the attached document

Reason / purpose for cross-reference:

read-across source

Key result

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

28 d

Interpretation of results:

not readily biodegradable

Conclusions:

By analogy with its hydrolysis product, trifluoromethanesulfonic anhydride is considered to be not readily biodegradable.

Description of key information

Trifluoromethanesulfonic anhydride is rapidly hydrolysed in water, therefore the conclusion as not readily biodegradable of its degradation product, i.e. trifluoromethanesulfonic acid, is considered as relevant for the assessment of trifluoromethanesulfonic anhydride.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Type of water:

freshwater

Additional information

The read-across justification with trifluoromethanesulfonic acid is provided in the attached document in the endpoint study record.

The aerobic ultimate biodegradation potential of Trifluoromethanesulfonic acid was determined in a test for ready biodegradability, according to the OECD 301D guideline and under GLP conditions.

Degradation was followed by analysis of dissolved oxygen over a 28-day period. The amount of oxygen taken up by the microbial population during biodegradation of the test item, corrected for uptake by the blank inoculum run in parallel, is expressed as a percentage of COD.

There was 0% of degradation of test item after 28 days. The positive control reached the pass level already on day 3. As degradation in the toxicity flask was more than 25 % at the end of the test, the test item can be stated as not toxic towards the inoculum in a concentration of 11.72 mg/L.

In these test conditions, Trifluoromethanesulfonic acid was not readily biodegradable.