4'-Ethyl-2,3-difluorbiphenyl-4-boronic acid

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2017-11-02 to 2018-01-08

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

July, 2010

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Batch Number: N017075555
Purity: 99% (HPLC)
Appearance: solid, white
Expiry Date: 2018-05-31
Storage Conditions: sealed, dark (15-25°C)

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

According to the results of the range finding test, the definitive study was carried out with 5 concentrations within the range 4 - 1000 mg/L test item in a geometrical series and with a dilution factor of 4. No pH adjustment was made.

All concentrations were weighed out directly in Erlenmeyer flasks and stirred overnight. Triplicates of the control without test item were included at the beginning and at the end of the test.
The reference item was tested with three concentrations within the concentration range 58 - 180 mg/L and a dilution factor of 1.8.

A fresh sample of activated sludge taken from the sewage plant Hildesheim was used for the test procedure. lt was washed twice and adjusted with chlorine free tap water if necessary to a dry
sludge concentration of 3.0 g/L ± 10 %.

The reference item (copper (II) sulphate pentahydrate) was tested at test concentrations of 58, 100, and 180 mg/L

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

Test System: Activated sludge
Origin: Municipal sewage treatment plant of 31137 Hildesheim, Germany
Reason for the selection: Non-adapted activated sludge from the sewage plant at Hildesheim is well suited as it receives predominantly municipal sewage and hardly any industrial chemical waste.
Pretreatment: The sludge was washed twice with chlorine free tap water and adjusted to a dry sludge concentration of 3.0 g/L ± 10 %. The sludge was used within 24 h after sampling.
Date of receipt: 2017-11-16
Dry sludge concentration: 3.28 g/L ( corresponding to 1.64 g/L suspended solids in the test vessels)

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Test temperature:

20.4°C

pH:

pH of activated sludge: 7.54
pH of synthetic waste water: 7.27

Dissolved oxygen:

Control samples : 7.09 - 7.52 mg/O2/L

Nominal and measured concentrations:

Range Finder: 10, 100 and 1000 mg/L
Main study: 4, 16, 64, 256 and 1000 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 500 mL Erlenmeyer flasks, DIN 12380
- Type: open
- Aeration:compressed air supply
- No. of vessels per test item concentration (replicates): 5
- No. of vessels of positive control (replicates): 3
- No. of vessels of control (replicates): 6
- Sludge concentration (weight of dry solids per volume): 3.28 g/L
- Nutrients provided for bacteria: no
- Nitrification inhibitor used (delete if not applicable): N-allylthiourea (only one replicate of the dose range finding study)

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



EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
TEST CONCENTRATIONS
- Range finding study: yes
- Test concentrations: 4, 16, 64, 256 and 1000 mg/L
- Results used to determine the conditions for the definitive study: range finding test

Reference substance (positive control):

yes

Remarks:

Copper (II) sulphate pentahydrate (CAS No. 7758-99-8)

Key result

Duration:

3 h

Dose descriptor:

EC10

Effect conc.:

45.6 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of heterotrophic respiration

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 heterotrophic respiration

Key result

Duration:

3 h

Dose descriptor:

NOEC

Effect conc.:

16 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of heterotrophic respiration

Results with reference substance (positive control):

copper-(II)-sulphate pentahydrate
EC50 = 101 mg/L

Validity criteria fulfilled:

yes

Conclusions:

The test item caused slight inhibiting effects on activated sludge of a municipal sewage treatment plant with an EC10 value of 45.6 mg/L and an EC50 value >1000 mg/L.

Executive summary:

The informtion for this endpoint study record was obtained from an experimental study. The OECD GLP criteria were met and the method applied are fully compliant with OECD TG 209. The test item caused slight inhibiting effects on activated sludge of a municipal sewage treatment plant with an EC10 value of 45.6 mg/L and an EC50 value >1000 mg/L.

Description of key information

The test item caused slight inhibiting effects on activated sludge of a municipal sewage treatment plant with an EC10 value of 45.6 mg/L and an EC50 value >1000 mg/L.

Key value for chemical safety assessment

EC50 for microorganisms:

1 000 mg/L

EC10 or NOEC for microorganisms:

45.6 mg/L