α,α,α-trifluorotoluene

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 1982-05-21 to 1987-07-12

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)

Deviations:

no

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

- Source: Activated sludge was obtained from a local sewage treatment plant in Fukuoka prefecture in Japan.
- Date: May, 21 in 1986
- Inoculum concentration: 1 drop/L mineral medium
- Preparation: Filtration of the sludge was conducted using the Standard Filter Papers No.2. First portion (200 mL) of the filtrate was disposed. After that, the remaining filtrate was collected, pre-conditioned with aeration and used as an inoculum for testing.

Duration of test (contact time):

28 d

Initial conc.:

2.4 mg/L

Based on:

test mat.

Initial conc.:

11.9 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

other: biochemical oxygen demand (BOD)

Details on study design:

- Test vessels: Incubator bottles for BOD testing, with glass stoppers (nominal volume of 100 mL)
- Test solution volume: 100 mL
- Temperature: 20 ± 1 °C
- Light period: complete darkness

Reference substance:

aniline

Key result

Parameter:

other: BOD

Value:

0

Sampling time:

28 d

Remarks on result:

other: Test concentration is 2.4 mg/L.

Key result

Parameter:

other: BOD

Value:

0

Sampling time:

28 d

Remarks on result:

other: Test concentration is 11.9 mg/L.

Details on results:

At the end of the incubation, GC analysis showed that the residual ratio of the test substance in the test suspension at an initial test substance concentration of 11.9 mg/L was 92 %.
The high volatility of the test substance led to the conclusion that it was impossible to conduct the biodegradability test using an oxygen consumption analyzer in a closed system. Therefore, the biodegradability test according to the OECD test guidelines 301D (Ready Biodegradability: Closed Bottle) was conducted. As the result, the biodegradability of the test substance could not be recognized in this study.

Results with reference substance:

Biodegradability by BOD for aniline is 74 % after 28 days.

Table 1. Biodegradability results

Conc. (mg/L)	Biodegradability (BOD in %)
	After 5 days	After 15 days	After 28 days
2.4	2 %	0 %	0 %
11.9	0 %	0 %	0 %

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

No biodegradation (0 % BOD) was observed after 28 days in accordance with OECD test guideline 301D.

Executive summary:

The ready biodegradability of the test item was determined with a non-adapted activated sludge over a test period of 28 days in the Closed bottle test according to OECD 301D. The test item was tested at concentrations of 2.4 and 11.9 mg/L. The oxygen concentration was measured with GC. The biochemical oxygen demand (BOD) was determined. No biodegradation of the test item (0 %) was observed after 28 days. In conclusion, the test item is not readily biodegradable as no biodegradation was observed under the test conditions.

Description of key information

In the OECD 301D study no biodegradation (0 % BOD) was observed after 28 days.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Type of water:

freshwater

Additional information

The ready biodegradability of the test item was determined with a non-adapted activated sludge over a test period of 28 days in the Closed bottle test according to OECD 301D (reference 5.2.1-1). The test item was tested at concentrations of 2.4 and 11.9 mg/L. The oxygen concentration was measured with GC. The biochemical oxygen demand (BOD) was determined. No biodegradation of the test item (0 %) was observed after 28 days. In conclusion, the test item is not readily biodegradable as no biodegradation was observed under the test conditions.