4''-Ethyl-2',3,4,5-tetrafluor-1,1':4',1''-terphenyl

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:

Sep 06, 2002 - Oct 21, 2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.4-D (Determination of the "Ready" Biodegradability - Manometric Respirometry Test)

Version / remarks:

1992

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

The activated sludge used for this study was washed by centrifugation and the supernatant liquid phase was decanted. The solid material was resuspended in tap water and again centrifuged. This procedure was repeated twice. An aliquot of the final sludge suspension was weighed, dried and the ratio of wet sludge to its dry weight was determined. Based on this ratio, calculated aliquots of washed sludge suspension, corresponding to 1.5 g dry material per litre were mixed with test water and then aerated until use.

Duration of test (contact time):

28 d

Initial conc.:

103 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

OECD TG 301 F

Reference substance:

aniline

Key result

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

28 d

Details on results:

Points of degradation plot (test substance):
0 % degradation after 28 d

Results with reference substance:

Points of degradation plot (reference substance): 85 % degradation after 14 d, 103 % after 28 d
Toxicity control: 43 % (14 d) and 46 % (28 d)

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

The degradation rate of the test material did not reach 60 % within the 10-day window and after 28 days of incubation. Thus the test item is not readily biodegradable.

Executive summary:

Purpose

The test item was investigated for its ready biodegradability in a Manometric Respirometry Test over a period of 28 days. The biodegradation was followed by the oxygen uptake of the micro organisms during exposure. As a reference item aniline was tested simultaneously under the same conditions as the test item, and functioned as a procedure control. The study was performed according to GLP and OECD TG 301F.

Result

Biodegradation of test item

After correction of the mean biochemical oxygen demand of the inoculum controls at the end of the 28 -day exposure period degradation rates of 0 % were found.

Biodegradation of Aniline

The reference item aniline was sufficiently degraded to 85 % after 14 days, and to 103 % after 28 days of incubation, thus confirming the suitability of the used activated sludge inoculum.

Biodegradation in the Toxicity Control

In the toxicity control containing both, the test item and the reference item aniline , 43 % biodegradation was noted within 14 days and 46 % biodegradation was determined after 28 days of incubation. Thus, the test item can be assumed to be not inhibitory on the activated sludge micro organisms.

Conclusion

The degradation rate of the test material did not reach 60 % within the 10-day window and after 28 days of incubation. Thus the test item is not readily biodegradable.

Description of key information

The test item is not readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

not biodegradable

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 by a manometric method. The study was conducted according to OECD TG 301F. The test item was tested at a concentration of 100 mg/L. To check the activity of the test system aniline was used as functional control. The percentage degradation of the functional control reached the pass level of 60 % within 7 days and came to a maximum of 103 % on day 28. The test item replicates did not reach the 10 % level (beginning of biodegradation) within 28 days. The test item is classified as not readily biodegradable within the 28-day period of the study.