Ethyl L-threoninate

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:

2000.06.20-2012.07.2000

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to other study

Qualifier:

according to guideline

Guideline:

other: OECD Test Method No. 301F, manometric respirometry test

GLP compliance:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch number of test material: Lot No. JN2TE005
- Expiration date of the lot/batch: 11-12-2004

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: -20C

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Details on inoculum:

Activated sludge from municipal waste water treatment plant was applied.
The activated sludge was stabilised under continuous aeration conditions for 1 day

Duration of test (contact time):

28 d

Initial conc.:

20 mg/L

Details on study design:

TEST CONDITIONS
- Composition of medium: deionised water, Activated sludge from municipal wastewater treatment plant, test substance/reference substance/blank
- Test temperature: 22+/-11°C
- pH: No data
- Aeration of dilution water: No data
- Continuous darkness: No data

TEST SYSTEM
- Number of culture flasks/concentration:3
- Method used to create aerobic conditions:respirometer containing pressure transducer. Oxygen is consumed and CO2 generated which is absorbed in a trap containing KOH. This creates a decrease in pressure equal to the oxygen consumed. The pressure transducer detects the change in pressure initiating an analytical process by which oxygen is supplied.
- Test performed in closed vessels.
SAMPLING
- Sampling frequency: daily
- Sampling method: daily readings/measurements

CONTROL AND BLANK SYSTEM
- Toxicity control: yes

Reference substance:

other: Sodium benzoate

Preliminary study:

no data

Parameter:

% degradation (CO2 evolution)

Value:

ca. 97

Sampling time:

28 d

Parameter:

% degradation (CO2 evolution)

Value:

ca. 85

Sampling time:

12 d

Details on results:

At the end of the 10 day window covering the period from day 2 to 12, the BOD was 85%+/-2% of the ThOD for complete oxidation of the test substance. A degradation of 97 % was observed after 28 days.
The difference between extreme replicates was 6% at the end of the test, which is in accordance with the validity criteria of a maximum deviation of 20%.

Results with reference substance:

A degrdation of 91 % was observed after 14 days (sodium benzoate), which is higher than the required 60% after 14 days.

no

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

The test substance L-TEE was ready biodegradable according to the test guideline OECD 301F. A degradation of 97%+/-3% of the ThOD was observed after 28 days.

Executive summary:

The biodegradation of L-TEE was tested according to the OECD guideline 301F. A biodegradation of 85 +/-2% was observed at the end of the 10-day window (day 2 -12) and 97%+/-3% degradation was observed after 28 days. Therefore L-TEE is considered to be readily biodegradable.

Description of key information

The biodegradation of L-TEE was tested according to the OECD guideline 301F. All criteria for readily biodegradabilty were fulfilled. Therefore L-TEE is considered to be readily biodegradable

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Type of water:

freshwater

Additional information

The biodegradation of L-TEE was tested according to the OECD guideline 301F. A biodegradation of 85 +/-2% was observed at the end of the 10-day window (day 2 -12) and 97%+/-3% degradation was observed after 28 days. Therefore L-TEE is considered to be readily biodegradable.