Triphenylphosphine oxide

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: Test procedures according to EU Directive 79/831/EEC Annex V, part C: Methods for the Determination of the ecotoxicity degradation - biodegradation, Manometric respirometry test.

Qualifier:

equivalent or similar to guideline

Guideline:

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

GLP compliance:

no

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge: Municipal activated sludge taken from a domestic wastewater treatment plant.

Duration of test (contact time):

28 d

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

SAMPLING
- Sampling frequency: continuously for 28 days


CONTROL AND BLANK SYSTEM
- Inoculum blank: yes
- Abiotic sterile control: yes
- Toxicity control: yes
- Other: inhibition of the inoculum

Reference substance:

aniline

Key result

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

28 d

Results with reference substance:

BOD/ThOD = > 60 %
DOC = 100 %
lag-phase: 5 d
Degradation-phase. 1 d

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

In a Manometric Respirometry Test according to EU Directive 79/831/EEC Annex V, part C and OECD Guideline 301 F, the test item was not readily biodegradable by OECD criteria (0 % degradation after 28 days).

Executive summary:

The ready biodegradability of the test item was assessed in a Manometric Respirometry Test according to EU Directive 79/831/EEC Annex V, part C and OECD Guideline 301 F. Non-adapted activated sludge from a domestic wastewater treatment plant was exposed to the test item over a duration of 28 days. Ready biodegradability was followed by O2 consumption of the microorganisms (measured continuously). In addition, an inoculum blank control, a procedure control with the reference substance aniline and a toxicity control both with the reference substance and the test item was conducted. In result, 0 % degradation (based on O2 consumption) was measured during the test. The BOD/ThOD was determined to be > 60 % and the DOC to be 100 %. The lag and degradation-phase was about 5 days and 1 day, respectively. In conclusion, under test conditions no biodegradation was observed. Thus, the test item is not regarded to be readily biodegradable by OECD criteria.

Description of key information

The test item is not readily biodegradable by OECD criteria (0 % degradation after 28 days).

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Additional information

The ready biodegradability of the test item was assessed in a Manometric Respirometry Test according to EU Directive 79/831/EEC Annex V, part C and OECD Guideline 301 F. Non-adapted activated sludge from a domestic wastewater treatment plant was exposed to the test item over a duration of 28 days. Biodegradation was followed by O2 consumption of the microorganisms (measured continuously). In addition, an inoculum blank control, a procedure control with the reference substance aniline and a toxicity control both with the reference substance and the test item were conducted. In result, 0 % degradation (based on O2 consumption) was measured during the test. The BOD/ThOD was determined to be > 60 % and the DOC to be 100 %. The lag and degradation-phase was about 5 days and 1 day, respectively. In conclusion, under test conditions no biodegradation was observed. Thus, the test item is not regarded to be readily biodegradable by OECD criteria.