3-(methylthio)propionaldehyde

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

other: DIN 38409-51: Deutsche Einheitsverfahren zur Wasser-, Abwasser- und Schlammuntersuchung; Summarische Wirkungs- und Stoffkenngrößen (Gruppe H); Bestimmung des Biochemischen Sauerstoffbedarfs in n Tagen nach dem Verdünnungsprinzip (Verdünnungs-BSB) (H 51)

Version / remarks:

1987

Qualifier:

according to guideline

Guideline:

other: DIN 38409-41: Deutsche Einheitsverfahren zur Wasser-, Abwasser- und Schlammuntersuchung; Summarische Wirkungs- und Stoffkenngrößen (Gruppe H); Bestimmung des Chemischen Sauerstoffbedarfs (CSB) im Bereich über 15 mg/L (H 41)

Version / remarks:

1980

GLP compliance:

no

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Duration of test (contact time):

5 d

Initial conc.:

1 g/L

Based on:

test mat.

Initial conc.:

2 g/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

BOD5 :

TEST CONDITIONS
- Test temperature: 20 °C
- Continuous darkness: yes

TEST SYSTEM
0.1% solution of the test substance: 615 mg/L
0.2% solution of the test substance: 1170 mg/L
average: 600 mg BOD5/g of the test substance

COD :
Oxidation of the ingredients with potassium dichromate with the addition of silver sulphate as catalyst in a strongly sulphuric acid solution.
TEST CONDITIONS
- reaktion temperature: 20 °C
- reaction time: 2 h

COD
0.1% solution of the test substance: 1500 mg/L COD
0.2% solution of the test substance: 2950 mg/L COD
average: 1500 mg COD / g of the test substance

Reference substance:

not required

Parameter:

BOD5

Value:

600 mg O2/g test mat.

Parameter:

COD

Value:

1 500 mg O2/g test mat.

Parameter:

BOD5*100/COD

Value:

40

Validity criteria fulfilled:

not specified

Interpretation of results:

not readily biodegradable

Conclusions:

The ready biodegradability of 3-(Methylthio)propionaldehyde was investigated in a study conducted to guideline DIN 38409-51 for BOD5 and DIN38409-41 for COD respectively. The average BOD5 after 5 days was 600 mg per g of the test substance. The average COD after 2 h of reaction was 1500 mg per g of the test substance. In case the BOD5/COD ratio is 0.5 or higher a substance can be regarded as readily biodegradable. Since this is not the case (0.4) the substance is regarded as not readily biodegradable.

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1992-10-29 to 1992-11-26

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

ISO DIS 9439 (Ultimate Aerobic Biodegradability - Method by Analysis of Released Carbon Dioxide)

Version / remarks:

December 1990

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

Principles of method if other than guideline:

Method similar to OECD 301B (DOC measurements were performed in addition to CO2 measurements and the precise kinetic of the DOC measurements was not provided).

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

sewage, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): obtained from influent of Saint-Germain au Mont d'Or STP treating domestic sewage.
- Storage length: used on day of preparation
- Pretreatment: coarse filtration, concentration by centrifugation and washed.
- Initial cell/biomass concentration: 3.8 E+07 bact./mL

Duration of test (contact time):

28 d

Initial conc.:

40 mg/L

Based on:

DOC

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium:
KH2PO4: 85.000 mg
K2HPO4: 217.500 mg
NH4CI: 5.000 mg
Na2HPO4, 2H2O: 334.000 mg
MgSO4, 7 H2O: 22.500 mg
CaCl2, 2 H2O: 36.400 mg
FeCl3, 6 H2O: 0.250 mg
bidistilled water: 1000 g
- Test temperature: 22 ± 2 °C
- Continuous darkness: yes

TEST SYSTEM
- Number of culture flasks/concentration: 2

SAMPLING
- Sampling frequency: 0, 1, 4, 5, 8, 11, 12, 15, 22 and 28 days

CONTROL AND BLANK SYSTEM
- Inoculum blank: 2
- Abiotic sterile control: 1
- Toxicity control: 1
- Reference control: 1

Reference substance:

acetic acid, sodium salt

Parameter:

% degradation (DOC removal)

Value:

100

Sampling time:

18 d

Parameter:

% degradation (CO2 evolution)

Value:

ca. 50

Sampling time:

28 d

Remarks on result:

other: Due to the uncertainty associated with the use of a biological reagent, the final value is presented close to 50%.

Details on results:

Remarks on the results obtained with the CO2 measurements:
The difference of biodegradation between the two flasks containing the substance at the end of the test is not more than 20% (41% and 52% after 28 days). More than 25% of biodegradation was obtained within 14 days in the inhibitory flask (61% of biodegradation after 15 days). No inhibitory effect was observed.
No abiotic degradation was observed in the flask containing the test medium, the substance and the biocide NaN3.

Remarks on the results obtained with the DOC measurements:
The difference of biodegradation between the two flasks containing the substance at the end of the test is less than 20% (99.8% and 100% after 18 days). 95.7% of biodegradation was obtained within 18 days days in the inhibitory flask. No inhibitory effect was observed. No significant abiotic degradation was observed in the flask containing the test medium, the substance and the biocide NaN3 (10.2% of degradation after 18 days).

Results with reference substance:

CO2 measurements: Less than 60% of biodegradation was reached within 14 days in the control flask containing sodium acetate (58% of biodegradation after 15 days). Nevertheless the level of 72% of biodegradation was reached at the end of the test.
DOC measurements: More than 70% of biodegradation was reached within 18 days in the control flask containing sodium acetate (93.5% of biodegradation after 18 days).

Validity criteria fulfilled:

not specified

Conclusions:

The ready biodegradabilitay of 3-(Mehylthio)propionaldehyde was investigated in a study conducted according to ISO9439 guideline (1990, method by analysis of the carbon dioxide released). Mesurements of the dissolved organic carbon (DOC) were performed in addition to the CO2 measurements. CO2 evolution reached 50% in 28 days. As DOC was shown to be 100% eliminated in 18 days in inoculated test vessels, and 10% in sterile vessels, the DOC removal was concluded to be biotic.

Reference 3

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1999-10-27 to 1999-11-24

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:

29. December 1992

Deviations:

no

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): obtained from influent of Saint-Germain au Mont d'Or STP treating domestic sewage.
- Storage length: used on day of preparation
- Pretreatment: coarse filtration, concentration by centrifugation and washed.
- Initial cell/biomass concentration: 7.7 E+066 bact./mL

Duration of test (contact time):

28 d

Initial conc.:

ca. 20 mg/L

Based on:

DOC

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

TEST CONDITIONS
- Composition of medium:
KH2PO4: 85.000 mg
K2HPO4: 217.500 mg
NH4CI: 5.000 mg
Na2HPO4, 2 H2O: 334.000 mg
MgSO4, 7 H2O: 22.500 mg
CaCl2, 2 H2O: 36.400 mg
FeCl3, 6 H2O: 0.250 mg
bidistilled water: 1000 g
- Test temperature: 20.7 °C - 22.8 °C
- Continuous darkness: yes

TEST SYSTEM
- Culturing apparatus: 0.5 L - Erlenmeyer flasks
- Number of culture flasks/concentration: 2

SAMPLING
- Sampling frequency: 0, 2, 6, 8, 14, 19, 21 and 28 days
- Sampling method: culture medium was mixed before samples was taken. Samples were filtered before analysis (0.22 µm)
- Sample storage before analysis: directly after sampling or storage at 4 °C for max. 48 h

CONTROL AND BLANK SYSTEM
- Inoculum blank: 2
- Abiotic sterile control: 1
- Toxicity control: 1
- Other: reference control: 1

Reference substance:

acetic acid, sodium salt

Parameter:

% degradation (DOC removal)

Value:

92

St. dev.:

1

Sampling time:

28 d

Details on results:

Remarks: The difference of biodegradation between the two flasks containing the substance at the end of the test is less than 20% .
More than 35% of biodegradation was obtained within 14 days in the inhibitory flask (81% of biodegradation after 14 days). No inhibitory effect was observed.
No abiotic degradation was observed in the flask containing the test medium, the substance and the biocide NaN3.

Results with reference substance:

More than 70% of biodegradation was reached within 14 days in the control flask containing sodium acetate (92% of biodegradation after 14 days) confirming the activity of the inoculum.

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

The test substance was degraded by 92% after 28 days under testing conditions. Thus, the substance is readily biodegradable according to the OECD criteria.

Description of key information

The test substance is readily biodegradable (92% after 28 days, DOC Die-Away Test).

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Type of water:

freshwater

Additional information

The key study on the ready biodegradability of the substance was conducted according to EU Method C.4-A. The degradation rate of the substance was determined by measuring the DOC removal during an incubation period of 28 days. The substance was incubated with activated sludge taken from a STP treating domestic sewage. Based on the dissolved organic carbon (DOC) removal a degradation of 92% was determined after 28 days. The 10-day window criterion was met. Thus, the substance is readily biodegradable according to OECD criteria.

Two additional studies testing the biodegradation of the substance are available. In a guideline study according to guideline ISO DIS 9439 the biodegradation of the substance was determined by measuring the CO2 evolution as well as the DOC content. Based on the DOC removal a degradation of 100% after 18 days was determined. The measurement of CO2 evolution resulted in a degradation of ca. 50% after 28 days. 

A study performed according to guideline DIN 38409-51 and DIN38409-41 respectively investigated the biodegradation based on the biological oxygen demand (BOD) after 5 days and chemical oxygen demand (COD). The average BOD5 was 600 mg/g of the test substance. The average COD after 2 h of reaction was 1500 mg/g of the test substance. Since the BOD5/COD-ratio is 0.4 (trigger: 0.5) the substance cannot be classified as readily biodegradable.

In conclusion the substance is readily biodegradable.