2,4,6-tri-n-propyl-2,4,6-trioxo-1,3,5,2,4,6-trioxatriphosphorinane

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:

1995-05-30 till 1995-06-27

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.4-A (Determination of the "Ready" Biodegradability - Dissolved Organic Carbon (DOC) Die-Away Test)

Version / remarks:

92/69/EEC, 29.12.1992

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 A (Ready Biodegradability: DOC Die Away Test)

Version / remarks:

1992

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

sewage, domestic, non-adapted

Details on inoculum:

- Source of inoculum: domestic sewage treatment plant in Frankfurt am Main-Sindlingen
- Preparation of inoculum for exposure: solids of the sewage sludge were centrifuged, washed, centrifuged again, and resuspended
- Pretreatment: Aerated over a period of 7 days to exhaust the soluble carbon content in the sludge
- Amount used: 4 ml/L sludge suspension with 30 g/L of the centrifuged sediment. The content of dry mass was 5.193 g/L in the suspension, corresponding to 20.8 mg/L dry mass in the final test volume
- State of acclimatization: not acclimatized to the test substance or the reference substance

Duration of test (contact time):

28 d

Initial conc.:

0.03 g/L

Based on:

DOC

Initial conc.:

0.081 g/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

TEST CONDITIONS
- Preparation of the stock solution: test item introduced into highly purified water, stirred at 21 °C over 3 hours
- Test temperature: 21 - 23 °C
- pH: 7.2
- pH adjusted: yes, with 1M NaOH
- Reaction medium: composition corresponds to the EEC Directive

TEST SYSTEM
- Culturing apparatus: 2 L Erlenmeyer vessels
- Number of culture flasks/concentration: 2
- Measuring equipment: pH meter, Portamess

SAMPLING
- Sampling points: after 0.125 (=3h), 1, 3, 7, 10, 15, 21, 27 and 28 days
- Sampling volume: 20 mL each for DOC analysis

CONTROL AND BLANK SYSTEM
- Toxicity control: reaction medium with test substance and reference

Reference substance:

benzoic acid, sodium salt

Key result

Parameter:

% degradation (DOC removal)

Value:

1.9

Sampling time:

28 d

Remarks on result:

other: max. degradation: 4.7% after 10 days

Details on results:

Points of degradation plot (test substance):
0 % degradation after 1 d
1.9 % degradation after 3 d
0 % degradation after 7 d
4.7 % degradation after 10 d
2.1 % degradation after 15 d
1.9 % degradation after 28 d

Results with reference substance:

Points of degradation plot (reference substance):
4.5 % degradation after 1 d
94 % degradation after 3 d
102 % degradation after 7 d

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

The biodegradation of the test item was determined as described in the OECD Guideline 301 A in a static test after 0.125, 1, 3, 5, 7, 10, 15, 21, 27 and 28 days. The degree of biodegradation was 1.9 % after an exposure of 28 days. Thus, the test item is not considered to be biodegradable under the test conditions chosen.

Executive summary:

The biodegradation of the test item was determined as described in the OECD Guideline 301 A in a static test after 0.125, 1, 3, 5, 7, 10, 15, 21, 27 and 28 days. The degree of biodegradation was 1.9 % after an exposure of 28 days. The elimination of the toxic control achieved >50 %. Thus, the test item is not considered to be biodegradable under the test conditions chosen.

Description of key information

The biodegradation of the test item was determined as described in the OECD Guideline 301 A in a static test after 0.125, 1, 3, 5, 7, 10, 15, 21, 27 and 28 days. The degree of biodegradation was 1.9 % after an exposure of 28 days. Thus, the test item is not considered to be biodegradable under the test conditions chosen.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Additional information

The biodegradation of the test item was determined as described in the OECD Guideline 301 A in a static test after 0.125, 1, 3, 5, 7, 10, 15, 21, 27 and 28 days. The degree of biodegradation was 1.9 % after an exposure of 28 days. The elimination of the toxic control achieved >50 %. Thus, the test item is not considered to be biodegradable under the test conditions chosen.