4-[Difluor(3,4,5-trifluorphenoxy)methyl]-3,5-difluor-4'-propyl-1,1'-biphenyl

Toxicity to microorganisms

Administrative data

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2009-05-28 to 2009-07-01

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2009

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test (Carbon and Ammonium Oxidation))

Version / remarks:

04 April 1984

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.11 (Biodegradation: Activated Sludge Respiration Inhibition Test)

Version / remarks:

30 May 2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

4-[difluoro(3,4,5-trifluorophenoxy)methyl]-2',3,5-trifluoro-4''-propyl-1,1':4',1''-terphenyl

EC Number:

619-490-8

Cas Number:

303186-36-9

Molecular formula:

C27H22F8O2

IUPAC Name:

4-[difluoro(3,4,5-trifluorophenoxy)methyl]-2',3,5-trifluoro-4''-propyl-1,1':4',1''-terphenyl

Test material form:

solid: bulk

Specific details on test material used for the study:

Batch Number: L57085385
Purity: 99.9% (GC)
Appearance: solid, colourless
Expiry Date: 2009-07-31
Storage Conditions: 15-25°C, in the dark

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Appropriate amounts of test item were directly weight into the test vessels and test water was added. The composition was stirred intensively
- Controls: pure water, synthetic sewage and inoculum, but without addition of test item

Test organisms

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

Test System: Activated sludge
Origin: Municipal sewage treatment plant of Darmstadt, Germany
Reason for the selection: Non-adapted activated sludge from the sewage plant at Bensheim is well suited as it receives predominantly municipal sewage and hardly any industrial chemical waste.
Pretreatment: The activated sludge was washed by centrifugation and the supernatant liquid phase was decanted. The solid material was re-suspended in tap water and again centrifuged. The latter
procedure was repeated three times. The washed sludge was re-suspended in tap water and sewage feed (50 mL per L) was added. The sludge was kept at room temperature under
continuous aeration until use overnight. Immediately before use, the dry weight of the activated sludge was determined, and diluted to 3.5 g/L with tap water. The pH of the activated sludge was
7.3 and therefore, no adjustment was necessary.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Test conditions

Test temperature:

20.4°C

pH:

control: 7.3 (start) to 8.6 (end)
test item: 7.3 (start) to 8.6 (end)

Dissolved oxygen:

Control samples : 6.9 mg O2/L

Nominal and measured concentrations:

test item: 10, 32, 100, 320, and 1000 mg/L
positive control: 3.2, 10 and 32 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass flasks (approx. 1 litre) and Karlsruher flasks (250 mL)
- Type: open
- Aeration:compressed air (0.8 litre per minute)
- No. of vessels per test item concentration (replicates): 1
- No. of vessels per positive control concentration (replicates): 1
- No. of vessels of control (replicates): 2
- Sludge concentration (weight of dry solids per volume): 3.5 g/L
- Nutrients provided for bacteria: no
- Nitrification inhibitor used: N-allylthiourea

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: deionized water



EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
TEST CONCENTRATIONS
- Test item concentrations: 10, 32, 100, 320, and 1000 mg/L

Reference substance (positive control):

yes

Remarks:

3,5-dichlorophenol

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Effect concentrations 2

Key result

Duration:

3 h

Dose descriptor:

NOEC

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Results with reference substance (positive control):

3,5-Dichlorophenol
EC50 = 8.1 mg/L

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The test item had no inhibiting effects on the respiration rate of activated sludge up to and including 1000 mg/L.
The NOEC was determined to be ≥ 1000 mg /L. The 3-hour EC10, EC20, and EC50 values could not be established.

Executive summary:

The influence of the test item on the activity of activated sludge was evaluated by measuring the respiration rate under defined conditions according to the OECD Guideline for Testing of Chemicals, No. 209: "Activated Sludge, Respiration Inhibition Test", adopted July 22, 2010.

The test item had no inhibiting effects on the respiration rate of activated sludge up to and including 1000 mg/L.

The NOEC was determined to be ≥ 1000 mg /L. The 3-hour EC10, EC20, and EC50 values could not be established.

The positive control 3,5-Dichlorophenol was tested in the same way as the test item. The 3-hour EC50 for total respiration was found to be 8.1 mg/L thus lying in the range of 5 - 30 mg/L recommended by the test guidelines. The result confirms the suitability of the activated sludge used.