4'-methoxyacetophenone

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:

1992-02-18 to 1992-03-17

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

no replicate was performed or recorded.

Qualifier:

according to guideline

Guideline:

EU Method C.4-B (Determination of the "Ready" Biodegradability - Modified OECD Screening Test)

Deviations:

yes

Remarks:

Tox-control not performed

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum: activated sludge, derived from the effluent of a laboratory-scale activated sludge plant receiving domestic sewage (Wupperverband)
- Test organisms: mixed culture of microorganisms
- Concentration of sludge: 0.5 mL / 900 mL
- Pretreatment: no
- sampling date: 02/18/1992

Duration of test (contact time):

28 d

Initial conc.:

20 mg/L

Based on:

DOC

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

TEST CONDITIONS
- Composition of medium: according to OECD Guideline 301 E
- Test temperature: 20-24 °C
- Continuous darkness: yes

SAMPLING
- Sampling frequency: sampling on days 7, 14, 21, 27 and 28

CONTROL AND BLANK SYSTEM
- Toxicity control: not performed
- procedure control: yes, with reference substance aniline

Reference substance:

aniline

Preliminary study:

Not performed

Test performance:

All validity criteria were fulfilled. The test item reached the 10 % level after 7 days and passed the level > 70 % after 14 days as a biodegradation rate of 100 % was already reached.

Key result

Parameter:

% degradation (DOC removal)

Value:

100

Sampling time:

28 d

Results with reference substance:

The reference substance in parallel procedure control was ready degraded (100%) within 28 days.

Table: DOC values [mg/L] for the blank control and the test item as well as degradation [%] of the test item after 0, 7, 14, 21 and 28 days.

Time	Blank	Test Item
	DOC (mg/l)	DOC (mg/l)	DOC cor. (mg/l)	Degradation (%)
0 h	2	19	17	0
7 d	2	17	15	12
14 d	2	0	0	100
21 d	2	0	0	100
28 d	2	0	0	100

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

The ready biodegradability of the test item was determined with a non-adapted activated sludge over a test period of 28 days in the Modified OECD Screening Test according to the OECD guideline 301 E and the EU Method C.4 -B. The test item is classified as readily biodegradable as the pass level of 70 % degradation was reached in a 10-d-window within the 28 days period of the study.

Executive summary:

The ready biodegradability of the test substance was investigated according to EU Method C.4 -B (Determination of the "Ready" Biodegradability - Modified OECD Screening Test) and GLP principles. The biodegradation of the test substance was followed by exposing it to microorganisms from the effluent of a laboratory-scale activated sludge plant (receiving domestic sewage). As a reference compound (procedure control) aniline was tested simultaneously. The test item concentration selected as appropriate was 20 mg/L DOC. The flasks were incubated for 28 days under aerobic and dark conditions at 20-24 °C. The biodegradability was derived from DOC removal within the test period. In result, the test item reached the 10 % level after 7 days and passed the level >70 % after 14 days as a biodegradation rate of 100 % was already reached. All validity criteria were fulfilled. In conclusion, the test item is regarded to be in the 10-d-window and after 28 days readily biodegradable.

Description of key information

The test item reached a biodegradation rate of 100 % after 14 days. The test item is regarded to be in the 10-d-window and after 28 days readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

A 28-day biodegradation study was carried out for the test substance according to EU Method C.4 -B (Determination of the "Ready" Biodegradability - Modified OECD Screening Test) and GLP principles. Test solutions were inoculated with activated sludge and incubated under aerobic conditions for 28 days. The DOC-value of the stock solution of the test item was 144 mg/L and the test temperature was in the range of 20 to 24 °C. A procedure control with the reference substance aniline was performed in parallel. The test substance was found to be 100 % degraded after 14 days. The 10-day window was met. Thus, the test substance is considered to be readily biodegradable. The reference substance was completely biodegraded (100%) after 28 days. All validity criteria of the guidelines were met.