butyl methylphosphinate

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1997

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1997

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Test material

Reference

Name:

Unnamed

Type:

Constituent

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

Activated sludge from the sewage plant at Hildesheim is well suited as it comprises mostly municipal sewage and hardly industrial chemical waste. The activated sludge is filtered with folded filter. The first 200 [ml] of the filtrate are not used. The second filtrate effluent from the domestic waste water is used to initiate inoculation.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

5 mg/L

Based on:

ThOD/L

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

The oxygen concentration was measured in the incubation vessels on day 0, 7, 14, 21 and 28.

Reference substance

Reference substance:

acetic acid, sodium salt

Results and discussion

Preliminary study:

The toxicity to bacteria was tested in the concentrations 13 and 30 [mg/L] according to OECD Guideline 209 in the DR.U.NOACK-LABORATORIUM. The test substance was not toxic in these concentrations.

% Degradation

% Degradation 1

Parameter:

% degradation (O2 consumption)

Value:

47

Sampling time:

7 d

% Degradation 2

Parameter:

% degradation (O2 consumption)

Value:

50

Sampling time:

14 d

% Degradation 3

Parameter:

% degradation (O2 consumption)

Value:

53

Sampling time:

21 d

% Degradation 4

Parameter:

% degradation (O2 consumption)

Value:

50

Sampling time:

28 d

Details on results:

The test substance reached the pass level of 10 [%] (begin of degradation) after two days. At the end of the test (day 28) the degradation rate reached a maximum of 50 [%]

BOD5 / COD results

Results with reference substance:

The biodegradability of the functional control achieved a maximum of 82 [%] after 28 days. The pass level > 60 [%] was reached by day 7. The quality criterion that the degradation should be > 60 [%] after 14 d was fulfilled.

Applicant's summary and conclusion

Conclusions:

The test substance was not readily biodegradable after 28 [d]. The pass level of > 60 [%] has not been reached neither in a 10 d-window nor after 28 days. After 28 days the degradation came to a maximum of 50 [%]. The test substance must be regarded to be not readily biodegradable.

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