3-Morpholinone, 4-[4-[(5S)-5-(aminomethyl)-2-oxo-3-oxazolidinyl]phenyl]-, hydrochloride (1:1)

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:

01/2006

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.4-D (Determination of the "Ready" Biodegradability - Manometric Respirometry Test)

Deviations:

no

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

Test Organisms:
Type: mixed population of aquatic microorganisms (activated sludge)
Origin: aeration tank of a wastewater plant treating predominantly domestic sewage (Wupper area water authority, STP Odenthal)
Date of collection: 2006-11-20
Concentration of inoculum: 30 mg/L ss

Pretreatment of the inoculum:
- the sludge was washed twice by adding mineral medium, centrifuging (10 min at 2000 rpm and 20 °C)
- 0.924 g of the wet sludge was dried in order to calculate the amount of wet sludge to achieve a concentration of activated sludge of 3 g/L (dry wet) suspended solids
- the calculated amount of sludge was first dissolved in mineral medium and then filled up to a defined end volume
- the inoculum was stored at room temperature under continuous shaking with aeration until use for max. 3 days

Duration of test (contact time):

28 d

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

Pretreatment of the test item:
- 25 mg of the test item were weighed out on aluminium foil
- test item and aluminium foil were added to the test flask containing 200 mL of mineral medium
- afterwards the flask content was made up to 250 mL with mineral medium containing inoculum to give a test concentration of 100 mg test item/L

Exposure conditions
- Test volume: 250 mL
- Test apparatus: Oxi Top System (WTW)
- Mixing: 1 magnetic stirrer per test vessel
- Incubation time: 28 days
- Incubation temperature: 22 +/- 1°C
- pH value after 28 d: 7.5-8.1

Reference substance:

benzoic acid, sodium salt

Remarks:

Purity 99% ; Batch No. 1206115 50306102

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

7 d

Parameter:

% degradation (O2 consumption)

Value:

0.5

Sampling time:

14 d

Parameter:

% degradation (O2 consumption)

Value:

0.2

Sampling time:

21 d

Key result

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

28 d

Results with reference substance:

The reference compound showed 86% after 14 days

Theoretical oxygen demand: 1.367 mg O₂/mg

Validity criteria fulfilled:

yes

Remarks:

(-Ready biodegradability of reference compound >= 60 percent within 14 days. -In the toxicity control degradation rates > 25 % within 14 days. -Replicates difference < 20%, -Oxygen uptake of blank inoculum =< 60 mg/L. -No pH influence. )

Interpretation of results:

not readily biodegradable

Conclusions:

Within 28 days, no degradation was determined, 0% degradation within 28d. 3-Morpholinone, 4-[4-[(5S)-5-(aminomethyl)-2-oxo-3-oxazolidinyl]phenyl]-, hydrochloride is considered to be "Not Readily Biodegradable". The reference compound sodium benzoate showed 86% degradation after 14 days.

Executive summary:

To test for its potential of biodegradation, the substance was incubated for 28 days in a continuously stirred 250 mL closed flask (in duplicate) in the dark with an inoculum originally collected from a local, predominantly municipal wastewater treatment plant. In this assay, biodegradation was estimated by biological oxygen demand (BOD) over time. BOD was measured daily by a manometer. The incubation temperature was 22 +/- 1 °C, pH was 7.5-8.1. The concentration of inoculum was 30 mg /L and the one of the substance was 100 mg/L. Degradation was calculated by substracting the amount BOD in the negative (inoculum only) control from that in the substance or positive control at any given time point and divided by the chemical oxygen demand (COD) or thereotical oxygen demand (ThOD). The 28-day degradation was 0% and for the positive control (with reference substance) the biodegrdation was 86%. In conclusion the substance is not readily biodegradable.

Description of key information

Within 28 days, no degradation was determined, 0% degradation within 28d. 3-Morpholinone, 4-[4-[(5S)-5-(aminomethyl)-2-oxo-3-oxazolidinyl]phenyl]-, hydrochloride is considered to be "Not Readily Biodegradable". The reference compound sodium benzoate showed 86% degradation after 14 days.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Type of water:

freshwater

Additional information

All validity criteria of the test method were met. The percent degradation of the reference compound sodium benzoate reached the level 86 % after 14 days.