4''-Butoxy-4-ethyl-2',2'',3''-trifluoro-[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:

2014 March 10 to 2014 October 08

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Principles of method if other than guideline:

NA

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, adapted

Details on inoculum:

The inoculum was derived from the secondary effluent of Shanghai
Longhua Sewage Plant. The inoculum was pre-conditioned by aerating the
secondary eftluent, without other treatment or addition, for 5-7 days at the
test temperature of 20 + 1°C. Control microbe counted at the range of
10000-1000000 orgs/l.

Suspended Solids: 3 g/L
Sludge in medium: 30 mg/L

Duration of test (contact time):

28 d

Initial conc.:

20 mg/L

Based on:

test mat.

Remarks:

final concentration was clearly above water solubility

Parameter followed for biodegradation estimation:

O2 consumption

Reference substance:

benzoic acid, sodium salt

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

28 d

Details on results:

Under the test conditions no biodegradation of test item could be observed.
The percentage degradation did not exceed 60 % within the 10-day window and after 28 days of incubation.
The test item is considered not readily biodegradable.
The reference Item sodium sodium benzoate was sufficiently degraded to 84 % after 14 days and 90 % after 28 days of incubation. The percentage degradation of the reference item confirms the suitability of the used activated sludge inoculum.

In the toxicity control containing both, test item and reference item 68 % biodegradation was noted within 14 days and 72 % biodegradation was determined after 28 days of incubation.

According to the test guidelines the test item can be assumed to be not inhibitory on the activated sludge micro organisms because degradation was > 25% within 14 days.
The oxygen demand in the abiotic control was zero; no correction of the test item degradation rates had to be done.

Results with reference substance:

The reference Item sodium sodium benzoate was sufficiently degraded to 84 % after 14 days and 90 % after 28 days of incubation. The percentage degradation of the reference item confirms the suitability of the used activated sludge inoculum.

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

Under the test conditions no biodegradation of test item could be observed. The percentage degradation did not exceed 60 % within the 10-day window and after 28 days of incubation. The test item is considered not readily biodegradable.

Executive summary:

In this OECD 301F Assay the results show no biodegradation of test item.

The percentage degradation did not exceed 60 % within the 10-day window and after 28 days of incubation.

The test item is considered not readily biodegradable.

The reference Item sodium sodium benzoate was sufficiently degraded to 84 % after 14 days and 90 % after 28 days of incubation. The percentage degradation of the reference item confirms the suitability of the used activated sludge inoculum.

According to the test guidelines the test item can be assumed to be not inhibitory on the activated sludge micro organisms because degradation was > 25% within 14 days.

The oxygen demand in the abiotic control was zero; no correction of the test item degradation rates had to be done.

Description of key information

The relevant study was performed according to GLP and the methods applied are fully compliant with OECD TG 301F. The test material was not readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

not biodegradable