Potassium 1,1,2,2,3,3,4,4,4-nonafluorobutane-1-sulphonate

Biodegradation in water and sediment: simulation tests

Administrative data

Endpoint:

biodegradation in water: sewage treatment simulation testing

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

2008

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

Study is of the free acid form of PFBS. In buffered solution, biodegradation testing on the acid is equivalent to testing on the potassium salt.

Data source

Reference

Reference Type:

publication

Title:

Degradation Studies of New Substitutes for Perfluorinated Surfactants

Author:

Quinete N, Orata F, Maes A, Gehron M, Bauer KH, Moreira I, Wilken RD

Year:

2010

Bibliographic source:

Arch Environ Contam Toxicol 59(1): 20-30; DOI 10.1007/s00244-009-9451-3

Report date:

2010

Materials and methods

Test guideline

Qualifier:

no guideline available

Principles of method if other than guideline:

- Principle of test: Fixed Bed Bioreactor system
- Short description of test conditions: Continuous flow-through at room temperature, neutral pH in darkness
- Parameters analysed / observed: primary biodegradation

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

1,1,2,2,3,3,4,4,4-nonafluorobutane-1-sulphonic acid

EC Number:

206-793-1

EC Name:

1,1,2,2,3,3,4,4,4-nonafluorobutane-1-sulphonic acid

Cas Number:

375-73-5

Molecular formula:

C4HF9O3S

IUPAC Name:

1,1,2,2,3,3,4,4,4-nonafluorobutane-1-sulfonic acid

Specific details on test material used for the study:

PFBS standard (98%) was obtained from Sigma–Aldrich (Germany)

Radiolabelling:

no

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

natural water: freshwater

Details on source and properties of surface water:

- Details on collection: Details of the inoculum are unclear. The paper describes the inoculum as being Rhine River water. It is presumed that the same sample, from km 463.6 near Biebesheim, was used as for a parallel closed bottle test. The water was recirculated at a flow rate of 16 mL/min through a glass column packed to 18 cm depth with glass beads to allow a biofilm to develop. The duration of biofilm development was not stated. The experiment was done with water from a pristine creek near Biebesheim, 5 L total volume. Aeration was provided by a membrane pump within the water reservoir. The experiment was run for 28 days .

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:

test mat. analysis

Results and discussion

% Degradation

Key result

Remarks on result:

other: No significant degradation, relative standard deviation of peak area ≤7%

Results with reference substance:

No reference substance was reported, however a second fluorinated surfactant tested in parallel showed ≥60% biodegradation within 28 days. This demonstrates biological efficacy of the developed bioreactor.

Applicant's summary and conclusion

Validity criteria

Validity criteria fulfilled:

not applicable

Conclusions:

PFBS was not biodegraded in a bioreactor system using a river water inoculum under neutral, aerobic conditions. Results are directly applicable to PFBSK+

Executive summary:

PFBS biodegradation was examined in a fixed-bed bioreacter using a river water source. River water was recirculated in a glass bead-packed column to allow a biofilm to develop. PFBS was recirculated for 28-days under aerobic conditions, at room temperature with neutral pH in darkness. Samples were taken weekly and analyzed by HPLC/MS/MS. A second fluorinated surfactant was examined in a parallel study. PFBS was not measurably biodegraded (RSD of HPLC peak areas ≤7%) over the test interval, whereas the other surfactant was degraded >60% at the same time. PFBS is not ultimately biodegradable. In neutral media, biodegradation testing on the free acid is equivalent to testing on the salt. Therefore, results for PFBS are directly applicable to PFBSK+.

The test was conducted using scientifically valid methods with a suitable level of detail, and results indicated the ability of the system to detect degradation of another, less-recalcitrant material. The results are considered reliable with restrictions and suitable for Risk Assessment, Classification & Labelling, and PBT analysis.