Potassium tris(pentafluoroethyl)trifluorophosphate

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:

11/12/2006-14/02/2007

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

The study was performed in compliance with the Good Laboratory Practice (GLP) regulations (revised in 1997, ENV/MC/CHEM(98)17). The method followed that described in the OECD Guidelines for Testing of Chemicals (Adopted: 4 April 1984) No 301F "Ready Biodegradability: Manometric Respirometry Test".

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Test material

Reference

Name:

Unnamed

Type:

Constituent

Details on test material:

Chemical Name: Potassium tris(pentafluoroethyl)trifluorophosphate
Supplier: Merck KGaA
Batch: S4693525
Specification: ionic liquid
Appearance: off white, crystalline powder with grey tinge
Expiration date: 30 Apr 2009
Strorage: at room temperature, in tightly closed brown-glass container protected from light and moisture
Purity: 98 %

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, adapted

Details on inoculum:

Activated sludge, micro organisms from a domestic waste water treatment plant was supplied by the sewage plant Rossdorf, Germany.
The activated sludge used for this study was washed by centrifugation and the supernatant liquid phase was decanted.
The solid material was re-suspended in tap water and again centrifuged.
This procedure was repeated twice. An aliquot of the final sludge suspension was weighed, dried and the ratio of wet sludge to its
dry weight was determined. Based on this ratio, calculated aliquots of washed sludge suspension, corresponding to 1.5 g dry material
per litre were mixed with test water and then aerated until use.
The washed activated sludge was aerated according to the test guideline and used one day later for the experiment.

Duration of test (contact time):

>= 28 d

Initial test substance concentration

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

according to guideline

Reference substance

Reference substance:

other: sodium benzoate

Results and discussion

Test performance:

The reference item sodium benzoate was sufficiently degraded to a mean of 87 % after 14 days, and to a mean of 90 %
after 28 days of incubation, thus confirming the suitability of the used activated sludge inoculum.

In the toxicity control containing both, the test item and the reference item sodium benzoate, a mean of 73 % biodegradation
was noted within 14 days and 75 % biodegradation after 28 days of incubation.
According to the test guidelines, the test item can be assumed not to be inhibitory on the activated sludge
micro organisms.

% Degradation

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

28 d

Details on results:

The degradation rate of the test item did not reach 60 % within the 10-day window and after 28 days of incubation.
Therefore, the test item is considered not to be readily biodegradable.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

The test item was found to be NOT readily biodegradable under the described conditions.

Executive summary:

The test item was investigated for its ready biodegradability in a manometric respirometry test over a period of 28 days.

The biodegradation was followed by the oxygen uptake of the micro organisms during exposure. As a reference item sodium

benzoate was tested simultaneously under the same conditions as the test item, and functioned as a procedure control.

Degradation rate of test item calculated by the oxygen consumption of the activated sludge microorganisms after 28 days

of incubation.

The degradation rate of the test item did not reach 60 % within the 10-day window and after 28 days of incubation.

Therefore, the test item is considered not to be readily biodegradable.

The reference item sodium benzoate was sufficiently degraded to a mean of 87 % after 14 days, and to a mean of 90 %

after 28 days of incubation, thus confirming the suitability of the used activated sludge inoculum.

In the toxicity control containing both, the test item and the reference item sodium benzoate, a mean of 73 % biodegradation

was noted within 14 days and 75 % biodegradation after 28 days of incubation.

According to the test guidelines, the test item can be assumed not to be inhibitory on the activated sludge

micro organisms.