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Environmental fate & pathways

Biodegradation in water: screening tests

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Administrative data

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

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1988
Report date:
1988

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 301 E (Ready biodegradability: Modified OECD Screening Test)
GLP compliance:
no

Test material

Constituent 1
Chemical structure
Reference substance name:
Methacrylamide
EC Number:
201-202-3
EC Name:
Methacrylamide
Cas Number:
79-39-0
Molecular formula:
C4H7NO
IUPAC Name:
2-methylprop-2-enamide
Test material form:
solid
Specific details on test material used for the study:
Supplier: Evonik Röhm GmbH, Darmstadt, Germany
Purity: 99.4 %, unstabilizied

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge (adaptation not specified)
Details on inoculum:
Secondary effluent of a sewage plant (Taunusstein, Germany), 1ml/l
Duration of test (contact time):
28 d
Initial test substance concentration
Initial conc.:
100 mg/L
Based on:
DOC
Parameter followed for biodegradation estimation
Parameter followed for biodegradation estimation:
DOC removal
Details on study design:
The purpose of the method is the measurement of the biodegradability of water soluble, non volatile organic compounds in anaerobic,
aqueous medium at a starting test concentration corresponding to 70 - 100 mg DOC/L
A predetermined amount of the compound is dissolved in an inorganic medium ( mineral nutrient solution, fortified with a trace element solution)
providing a concentration corresponding to 5 - 40 mg DOC/L. The solution is inocculated with a small number of microorganisms from a mixed
population and aerated at 20 - 25 °C in the dark or at least in diffuse light only. The degradation is followed by DOC analysis over a 28-day period.
The procedure is checked by means of a standard.
A control with inoculation, but without either test material or standard, is run parallelly for the determination of DOC blanks.
The reproducibility of the method is appropriate for a screening test with was solely an acceptance but no rejective function.

Membrane filter apparatus, filters 0,45 µm
DOC analyser (Maihak)
2 L-bottles, aeration installation

TEST CONDITIONS
- Composition of medium: A stock solution of the test substance in water was prepared. Enough stock solution was added to the nutrient solution to achieve a carbon content of 50 - 100 mg DOC/L. The reaction vessel was filled with 2000 ml of the nutrient solution and inoculated with 1 ml/L of the inoculum
- Additional substrate: N, P
- Test temperature: 20-25 °C
- pH: no data
- Aeration of dilution water: The opening of the test vessel was covered (e.g. aluminium foil) in such a way that the exchange of air between the flask
and the surrounding atmosphere in not unduly impeded. The vessel was than aerated.
- Suspended solids concentration: 1 ml inoculum/L
- Continuous darkness: yes


TEST SYSTEM

- Number of culture flasks/concentration: 1

SAMPLING
- Sampling frequency: at the beginning and after 1, 2, 3, 6, 10, 13, 16, 21 and 28 days.
- Sampling method: samples were taken in duplicate
Only necessary volumes of culture should be drawn for each determination: however, they must be large enough for the membrane filtration or
centrifugation preceding the carbon determination. Evaporation losses are to be made up by adding water. Material adhering to the wall of the vessel must be dissolved or suspended before sampling. The membrane filtration or centrifugation must be done immediately. The filtered or centrifuged
sample must be analysed on the same day. The test can be finished before the 28th day if complete mineralisation has been accomplished.
The filtrates are analysed on a DOC/TOC instrument using linear calibration range.

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes
- Toxicity control: no

STATISTICAL METHODS: no data
Reference substance
Reference substance:
diethylene glycol

Results and discussion

% Degradation
Key result
Parameter:
% degradation (DOC removal)
Value:
97
Sampling time:
28 d
Details on results:
10 day-window fullfilled
Details see chapter below: Any other information on results incl. tables

BOD5 / COD results

Results with reference substance:
Diethyleneglycole as reference substance was found to be 98% biodegradable within 21 days.

Any other information on results incl. tables

Results: Sample No. 8808AL44341 methacrylamide The substance was examined in two differentsets. Samples were taken after different times and examined for DOC.

Time

test 1

elimination of DOC in %

test 2

elimination of DOC in %

arithmetic mean of test 1 and 2

elimination of DOC in %

3 hours

19

33

26

1 day

5

3

4

2 days

3

1

2

3 days

16

14

15

6 days

60

32

46

10 days

96

78

78

13 days

96

96

96

16 days

93

92

92.5

21 days

98

99

98.5

28 days

97

97

97

The results show an adsorption of substance after 3 hours. The biodegradation process starts after 2 days.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
readily biodegradable
Conclusions:
Methacrylamide is regared as readily biodegradable based upon the OECD 301E study.
Executive summary:

Methacrylamide was tested in an 28 day OECD 301E screening test for readily biodegradation. 97 % biodegradation was achieved after 28 days, fulfilling 10 day-window.

Therefore methacrylamide is regarded as readily biodegradable based on OECD 301E study.