Ethyl difluoroacetate

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Report date:

2008

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EPA OPPTS 835.3120 (Sealed Vessel Carbon Dioxide Production Test)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Ethyl difluoroacetate

EC Number:

207-223-4

EC Name:

Ethyl difluoroacetate

Cas Number:

454-31-9

Molecular formula:

C4H6F2O2

IUPAC Name:

ethyl 2,2-difluoroacetate

Details on test material:

- Name of test material (as cited in study report): Ethyl difluoroacetate
- Physical state: liquid / colorless, clear
- Analytical purity: 99.9%
- Batch No.: 33244/106 A
- Storage condition of test material: Storage at refrigerator, avoid temperatures >70 °C

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge: municipal activated sludge from the wastewater treatment plant of the city Mannheim, Germany
- Preparation of inoculum for exposure: A suitable aliquot of the activated sludge suspension was sieved by a finely woven mesh with a mesh size about 1 mm. After settling the supernatant was discarded and the sludge suspension was filled up with tap water. This suspension was pre-aerated for about 24 hours at room temperature. The sludge of the suspension was adjusted to a concentration 800 mg/L of dry weight and then added to the
test vessels to obtain a sludge concentration of 4 mg/L dry substance.
- Concentration of sludge: 4 mg/L dry substance

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

52 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

TOC removal

Details on study design:

TEST CONDITIONS
- Composition of medium: 160 ml (aqueous phase) containing 4.4 µl (52.0 mg/L) test substance, 90 ml mineral medium, 0.5 ml (800 mg/L dry matter) inoculum, 9.5 ml water
- Test temperature: 22 ± 2 °C
- pH: 7.4 ± 0.2
- pH adjusted: no

TEST SYSTEM
- Culturing apparatus: 160 ml incubation bottles filled up to a volume of 100 ml closed with butyl rubber septa gas tight
and shaken
- Number of culture flask
- 23 blank control assays
- 23 test substance assays
- 23 inhibition control test assays
- 14 reference substance assays
- 5 assays for abiotic control

SAMPLING
- Sampling frequency: at Day 3, 7, 10, 14, 21, 28

Reference substance

Reference substance:

aniline

Results and discussion

% Degradation

Parameter:

% degradation (TOC removal)

Value:

40 - 50

Sampling time:

28 d

Details on results:

- Duration of the adaptation phase: 2 days
- Elimination of the test substance at physical chemical control at the end of exposure (%TIC/TOC): < 10
- Degradation degree in the inhibition control after 14 days (% TIC/TOC): 48

BOD5 / COD results

Results with reference substance:

- Degradation degree of the reference substance after 14 days (% TIC/TOC): 60%

Applicant's summary and conclusion

Interpretation of results:

other: partly/moderately biodegradable