o-(trifluoromethyl)benzamide

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:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

o-(trifluoromethyl)benzamide

EC Number:

206-637-2

EC Name:

o-(trifluoromethyl)benzamide

Cas Number:

360-64-5

Molecular formula:

C8H6F3NO

IUPAC Name:

2-(trifluoromethyl)benzamide

Test material form:

solid: crystalline

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

Activated sludge from the municipal wastewater treatment plant Breisgauer Bucht was used as inoculum with a concentration corresponding to 30 mg dry solids per litre. The treatment plant clarifies predominantly domestic wastewater of the region of Freiburg and has a capacity of 600.000 inhabitant equivalents. Sampling date of activated sludge was 9 August 2016. Dry solid of the activated sludge was determined as 3.4 g/L by weight measurements after 2.0 h drying at 105°C (mean of triplicate measurements). The activated sludge was washed twice with tap water by settling the sludge, decanting the supernatant and re-suspending the sludge.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

54 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Reference substance

Reference substance:

acetic acid, sodium salt

Results and discussion

% Degradation

Key result

Parameter:

% degradation (O2 consumption)

Value:

4.7

Sampling time:

28 d

BOD5 / COD results

Results with reference substance:

The reference compound sodium acetate reached the pass level for ready biodegradability (60% ThOD and 10-day window) within 8 days. The pH in the test bottles at the end of the test was 8.8 - 9.0.

Any other information on results incl. tables

Test item:

The biodegradation of the test item was 4.7% within 28 days (mean value of three

replicates, see table 2). Therefore the criterion for ready biodegradability was not met (60%

ThOD and 10-day window).

The pH in the test bottles at the end of the test was 7.6.

Toxicity control:

The degradation in the toxicity control reached 26.7% within 8 days (see table 2) and was thus above the criterion for inhibition effects to the inoculum (<25% on day 14). The test item had no toxic effect to the inoculum according to the validity criteria of OECD 301. The pH in the vessel was 8.6.

Blank:

The oxygen consumption of the blanks was 18.7 mg O2/L in 28 days (mean of three replicates, see table 1). The pH in the vessels was 7.6.

Temperature:

The temperature range was 20.1 - 21.6 °C throughout the whole study.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

The biodegradation of the test item was 4.7% within 28 days (mean value of three replicates, see table 2). Therefore the criterion for ready biodegradability was not met (60% ThOD and 10-day window).