4-Bromo-2-fluoro-N-methylbenzamide

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:

30 OCT 2020 to 27 NOV 2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2021

Report date:

2021

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

July 1992

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: MEP, P.R. China, the Guideline for the Testing of Chemicals, Degradation and Accumulation No. 301F “Manometric Respirometry Test”.

Version / remarks:

Second Edition (2013.9)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

4-Bromo-2-fluoro-N-methylbenzamide

EC Number:

808-257-8

Cas Number:

749927-69-3

Molecular formula:

C8H7BrFNO

IUPAC Name:

4-Bromo-2-fluoro-N-methylbenzamide

Test material form:

solid: particulate/powder

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- lot/batch number of test material: FFP-106-200011
- Expiry date: 17 March 2021 (retest date)
- Physical Description: Almost white powder
- Purity: 99.0%
- Purity test date: 21 MAR 2020
- Purity correction factor: no
STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: At room temperature
- Stability under storage conditions: no data
- Stability under test conditions: no data
- Solubility and stability of the test item in the solvent/vehicle: no data
TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Final preparation of a solid: not applicable

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge: domestic wastewater treatment plant, Shenyang North, P.R. China
- Storage conditions: aerobic conditions at 22.2 - 22.8°C
- Storage length: the inoculum was collected 2 days before the test exposure was started
- Preparation of inoculum for exposure: coarse particles were removed by filtration trough a fine sieve and the sample was allowed to settle; after the supernatant was discarded, the sludge was washed twice with mineral medium followed by resuspension in mineral medium;
- Concentration of sludge: 9.69 g/L as suspended solids (SS)

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

85.6 mg/L

Based on:

ThOD

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: test water prepared according to test guidelines.
Mineral stock solution A
- KH2PO4, 4.2502 g
- K2HPO4, 10.8753 g
- Na2HPO4.2H2O 16.7001 g
- NH4Cl: 0.2500 g
Dissolved in Milli-Q water and made to 500 mL. The pH of the solution was 7.72, adjusted to 7.52 with HCl

Mineral stock solution B: 3.6403 g CaCl2.2H2O dissolved in 100 mL Milli-Q water
Mineral stock solution C: 2.2500 g MgSO4.7H2O dissolved in 100 mL Milli-Q water
Mineral stock solution E: 0.0251 g FeCl3.6H2O, 0.56 K2-EDTA dissolved in 100 mL Milli-Q water

For 1 liter of mineral medium, 10 mL stock solution A was added to approximately 800 mL distilled water and the mixture stirred before adding, sequentially, 1 mL each of stock solutions B, C and D. After mixing, the mixture was made up to 1 liter with distilled water. In total 5 L mineral medium was prepared. The pH of the mineral medium was 7.57.

- Suspended solids concentration: initially 30 mg dw/L
- Continuous darkness: yes
SAMPLING
- Sampling frequency: every day during 28 days
CONTROL AND BLANK SYSTEM
- Biotic control: yes, two replicates with inoculum
- Toxicity control: yes
- Procedure control: yes, 1 replicate with reference substance and inoculum

Reference substance

Reference substance:

benzoic acid, sodium salt

Remarks:

sodium benzoate

Results and discussion

% Degradation

Key result

Parameter:

% degradation (O2 consumption)

Value:

1.5

Sampling time:

28 d

Remarks on result:

other: average of two replicates

BOD5 / COD results

Results with reference substance:

The biodegradation of the reference substance (Sodium benzoate) attained 60.4% after 1 day and 20
hours, 81.5% after 14 days and 91.1% after day 28.

Any other information on results incl. tables

In the Toxicity Control (TC) test mixture, more than 25% biodegradation occurred within 14 days (40.3%, based on ThOD). Therefore, the test item was considered not to inhibit microbial activity under test conditions.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Based on the results, the percentage biodegradation of T003669 within 28 days did not exceed the pass level of 60% biodegradation based on ThOD. The test item did not meet the criteria for “ready biodegradability” under the described test conditions.