8-Chloro-6-(trifluoromethyl)imidazo[1,2-a]pyridine-2-carboxylic acid

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EPA OPPTS 835.3110 (Ready Biodegradability)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

1

Reference substance name:

8-chloro-6-(trifluoromethyl)imidazo[1,2-a]pyridine-2-carboxylic acid

Cas Number:

353258-35-2

Molecular formula:

C9H4ClF3N2O2

IUPAC Name:

8-chloro-6-(trifluoromethyl)imidazo[1,2-a]pyridine-2-carboxylic acid

Specific details on test material used for the study:

Test substance: IN-QEK31-011
Batch No.: SG0312574
Purity: 98.2%

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

other: effluent (collected from a treatment plant)

Duration of test (contact time):

29 d

Initial test substance concentration

Initial conc.:

40 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

CO2 evolution

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

% Degradation

Key result

Parameter:

% degradation (CO2 evolution)

Value:

26.98

Sampling time:

29 d

BOD5 / COD results

Results with reference substance:

The percent degradation of reference item was 98.4 at the end of the test.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

other: not readily biodegradable but may be considered biodegradable as there was 26.98 % degradation during the treatment period

Conclusions:

The test item was considered as not readily biodegradable, as only 26.98 % degradation was achieved during the test period of 29 days. However, it may be considered biodegradable as there was 26.98 % degradation during the treatment period.

Executive summary:

The ready biodegradability of the test item was tested using the CO2 Evolution Test. The test item was added to two replicate test vessels at the concentration of 40 mg/L of mineral medium (equivalent to 16.3 mg of Total Organic Carbon/L). Two control treatments containing only the inoculum, one positive control treatment and one toxicity control treatment containing the test item and the positive control were also tested. All the treatments were added with inoculum from secondary effluent treatment plant receiving predominantly domestic sewage.

Treatment mixtures were aerated for 29 days with carbon dioxide (CO2) free air. The CO2 released was trapped in a series of bottles containing barium hydroxide, which were connected to the outlet of each test vessel. The residual barium hydroxide was measured on the Day 2, 4, 7, 9, 11, 16, 21, 25 and 29 after the initiation of the test.

There was 26.98 % degradation of test item during the treatment period while, the percent degradation of reference item was 98.4 % and the toxicity control was 65.33 % at the end of the test.

The test fulfilled all the validity criteria.

Based on the pass levels (60 % of bio-degradation in the 10-day window period), the test item was considered as not readily biodegradable, as only 26.98 % degradation was achieved during the test period of 29 days. However, it may be considered biodegradable as there was 26.98 % degradation during the treatment period.