Reaction mass of morpholine and 6-[(p-tosyl)amino]hexanoic acid, compound with morpholine (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:

From October 4, 2007 to November 1, 2007

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 306 (Biodegradability in Seawater)

Version / remarks:

1992

Deviations:

no

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

natural water: marine

Remarks:

Biologically active

Details on inoculum:

- Source of inoculum: Biologically active natural seawater collected from Anglesey Sea Zoo in North Wales on September 5, 2007
- Storage conditions: Maintained in the dark prior to use
- Storage length: ~4 weeks
- Preparation of inoculum for exposure: Seawater was aged prior to use by gentle aeration at 15 ± 2 °C
- Water filtered: After collection the seawater was coarse filtered and then maintained in the dark

INOCULUM PROPERTIES (at collection)
- Temperature: 17.0 °C (in the study all bottles were incubated at 17.5 - 20.5 °C)
- Salinity: 31.4 g/l
- pH: 7.64
- Dissolved oxygen: 100.0 %

Duration of test (contact time):

28 d

Initial conc.:

2.5 mg/L

Based on:

test mat.

Initial conc.:

3 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Remarks:

i.e. Dissolved oxygen (DO), used to derive % biodegradability in conjunction with calculated chemical oxygen demand (COD)

Details on study design:

TEST CONDITIONS
- Composition of medium: Natural, nutrient fortified seawater that had been coarse filtered. Test medium was prepared according to the method detailed in STL Runcorn SOP III.36
- Test temperature: All bottles were incubated at 17.5 - 20.5 °C
- pH: 7.64 at point of collection of seawater.
- Aeration of dilution water: Seawater received gentle aeration prior to use
- Continuous darkness: Yes, all bottles were incubated in the dark

TEST SYSTEM
- Culturing apparatus: Sealed glass BOD bottles of nominal 272 ml volume
- Number of culture flasks/concentration: Duplicate bottles were prepared for each of the sample days, for each test concentration of 2.5 mg/l and 3.0 mg/l test substance, and 2.5 mg/l sodium benzoate (a reference material to monitor microbial activity). Three replicates were prepared for use as control vessels for each day, which contained nutrient fortified seawater only.
- Method used to create aerobic conditions: Gentle aeration of seawater prior to test use
- Test performed in closed/open vessels: Closed bottle procedure

SAMPLING
- Sampling frequency: Days 0, 3, 7, 14, 21, and 28

CONTROL AND BLANK SYSTEM
- Inoculum blank: Yes, nutrient fortified seawater only (controls)

STATISTICAL METHODS:
The calculated COD value and dissolved oxygen data recorded at each analysis point (including day 0 readings) were processed to derive the percentage (%) degradability of the test material. Degradation values were calculated using the equation:
% Degradability = (BOD mgO2/mg test material / COD (mgO2/mg)) x 100

Reference substance:

benzoic acid, sodium salt

Remarks:

2.5 mg/l

Test performance:

No deviation from the guideline was reported

Key result

Parameter:

% degradation (O2 consumption)

Remarks:

2.5 mg/l p-toluene sulphonamidocaproic acid morpholine salt

Value:

26.2

Sampling time:

28 d

Key result

Parameter:

% degradation (O2 consumption)

Remarks:

3.0 mg/l p-toluene sulphonamidocaproic acid morpholine salt

Value:

19.5

Sampling time:

28 d

Details on results:

At 2.5 mg/l and 3.0 mg/l of p-toluene sulphonamidocaproic acid morpholine salt, % biodegradability was reported to be 26.2 and 19.5 % respectively after 28 days. This would suggest that the test substance has a limited potential for degradation under these experimental conditions.

Key result

Parameter:

COD

Value:

1.571 other: mg/mg

Remarks on result:

other: Calculated with COD equation in STL Runcorn SOP III.1

Results with reference substance:

After day 28, sodium benzoate (2.5 mg/l) had a % biodegradability of 71.9 %. The inoculum was considered to be biologically active.

Summary Table

Material (mg/l)	% Degradability
	Day 3	Day 7	Day 14	Day 21	Day 28
p-Toluene sulphonamidocaproic acid morpholine salt (2.5)	*	1.5	12.5	10.2	26.2
p-Toluene sulphonamidocaproic acid morpholine salt (3.0)	0.4	3.0	32.3	7.6	19.5
Sodium benzoate (2.5)**	48.9	74.7	46.5	61.3	71.9

**Using the calculated theoretical oxygen demand (ThOD) of sodium benzoate as 1.67 mgO2/mg

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

By the end of the experiment on Day 28, the test substance at 2.5 and 3.0 mg/l had been biodegraded by 26.2 and 19.5 % (5.81 and 5.87 mgO2/L), respectively. It can be concluded that the substance is not ready biodegradable.

Executive summary:

The ready biodegradation of the test substance was determined in a biological oxygen demand (BOD), GLP-certified test undertaken in accordance with OECD Guideline 306 (Biodegradability in Seawater).

The aim of the OECD 306 test is to establish the biodegradability of an organic material in a marine environment. Natural seawater considered to be biologically active was acquired from North Wales and nutrient fortified for use as the study inoculum. The registration substance at 2.5 and 3.0 mg/l, sodium benzoate at 2.5 mg/l (as a reference material to monitor microbial activity), and a seawater only blank were maintained at 17.5 - 20.5 °C in the dark and reviewed on day 0, 3, 7, 14, 21, and 28. Measurement for oxygen was taken in the form of DOC at the time intervals specified and COD calculated. DOC and COD were used to determine percentage (%) biodegradability of the test material.

The % biodegradation of sodium benzoate was reported to be 71.9 % over the 28-day study duration, indicating a biologically active inoculum, with a DOC of 3.83 mgO₂/L. COD for the test substance was found to be 1.571 mg/mg.

By the end of the experiment on Day 28, the test substance at 2.5 and 3.0 mg/l had been biodegraded by 26.2 and 19.5% (5.81 and 5.87 mgO₂/L), respectively. It can be concluded that the substance is not ready biodegradable.

Description of key information

By the end of the experiment on Day 28, the test substance at 2.5 and 3.0 mg/l had been biodegraded by 26.2 and 19.5 % (5.81 and 5.87 mgO2/L), respectively. It can be concluded that the substance is not ready biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Type of water:

marine water