N,N'-[(methylimino)dipropane-1,3-diyl]dioleamide

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:

2017-06-22 to 2017-08-22

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

adopted 1992-07-17

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure):
Inoculum of the aqueous phase of non-adapted activated sludge from Municipal sewage treatment plant, 31137 Hildesheim, Germany
Receipt 2017-06-15

Pretreatment:
The activated sludge was washed twice with chlorine free tap water. After the second washing the settled sludge was resuspended in mineral salts medium and was maintained in an aerobic condition by aeration for 2 hours.
Thereafter the sludge was homogenized with a blender. After sedimentation the supernatant was decanted and maintained in an aerobic condition by aeration with CO2-free air for 7 days. 10 mL/L were used to initiate inoculation.
Colony forming units in the test vessels: approx. 107 - 108 CFU/L

Duration of test (contact time):

60 d

Initial conc.:

18 mg/L

Based on:

test mat.

Initial conc.:

51.7 mg/L

Based on:

ThOD

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: Mineral salts medium according to OECD 301 F
- Additional substrate: no
- Solubilising agent (type and concentration if used): no
- Test temperature: 20.0 – 20.7 °C
- pH: 7.70
- pH adjusted: no
- CEC (meq/100 g):
- Aeration of dilution water: 24h
- Suspended solids concentration: no information
- Continuous darkness: Brown glass bottles

TEST SYSTEM
- Culturing apparatus: Brown glass bottles (volume 500 mL)
- Number of culture flasks/concentration:
• two for the inoculum control (C1, C2)
• one for the functional control (R1)
• two for the test item (P1, P2)
• one for the toxicity control (T1)

- Method used to create aerobic conditions:
- Method used to create anaerobic conditions:
- Measuring equipment:
OxiTop OC110 controller with software Achat OC, WTW
OxiTop measuring heads, WTW
Stirring platform, WTW
The oxygen consumption was determined in the incubation vessels by the OxiTop® measuring system during the 60 d incubation period (every 112 minutes).

CONTROL AND BLANK SYSTEM
• inoculum control
• functional control
• toxicity control

Reference substance:

benzoic acid, sodium salt

Key result

Parameter:

% degradation (O2 consumption)

Remarks:

replicate01

Value:

56

Sampling time:

28 d

Key result

Parameter:

% degradation (O2 consumption)

Remarks:

replicate01

Value:

78

Sampling time:

60 d

Key result

Parameter:

% degradation (O2 consumption)

Remarks:

replicate02

Value:

56

Sampling time:

28 d

Key result

Parameter:

% degradation (O2 consumption)

Remarks:

replicate02

Value:

75

Sampling time:

60 d

Biodegradation [%] of the Test Item N,N’-[(methylimono)bis(trimethylene)]bis(oleamide)

 

		Biodegradation [%] Study Day [d]
	Replicate	7	14	21	28	35	49	60
Test Item 18mg/L	1	4	23	41	56	64	73	78
	2	4	22	38	56	64	73	75
Functional Control 45 mg/L		77	87	88	88	88	86	88
Toxicity Control 18mg/L Test Item + 45 mg/L Reference Item		44	52	63	73	81	83	87

 

Validity criteria fulfilled:

yes

Interpretation of results:

inherently biodegradable

Conclusions:

The test substance N,N’-[(methylimono)bis(trimethylene)]bis(oleamide) is classified as inherently biodegradable within the 60 day period of the study.

Executive summary:

The ready biodegradability of N,N’-[(methylimono)bis(trimethylene)]bis(oleamide) was determined with non-adapted activated sludge in the Manometric Respirometry Test according to OECD guideline 301 F for a period of 60 days. The test item concentration selected as appropriate was 18 mg/L, corresponding to a ThOD of 51.7 mg O2/L (56.9 mg O2/L with nitrification) per test vessel. The oxygen was depleted by the respiration of bacteria and the degradation was followed by measuring the oxygen concentration. The biodegradation rate is therefore expressed as the percentage BOD (biological oxygen demand) and was calculated for each study day.

 

The mean oxygen depletion in the inoculum control was 13.9 mg O2/L on day 28 and on day 60 21.5 mg O2/L.

 

In order to check the activity of the test system sodium benzoate was used as functional control. The pass level > 60% was reached within 3 days. The biodegradation reached a maximum of 89% degradation on day 31.

In the toxicity control containing both test and reference item 52% degradation occurred within 14 days. After 28 days the biodegradation was 73% and after 60 days it came to 87%. The degradation of the reference item was not inhibited by the test item.

 

The mean of replicates of the test item reached the 10% level (beginning of biodegradation) on day 11 and the 60% pass level was reached on day 32. The mean biodegradation on day 28 was 56% and on day 60 77%. 

The test substance N,N’-[(methylimono)bis(trimethylene)]bis(oleamide) is classified as inherently biodegradable within the 60 day period of the study.

 

 

Description of key information

The test substance N,N’-[(methylimono)bis(trimethylene)]bis(oleamide) is classified as inherently biodegradable within the 60 day period of the study.

Key value for chemical safety assessment

Biodegradation in water:

inherently biodegradable

Type of water:

freshwater

Additional information

The ready biodegradability of N,N’-[(methylimono)bis(trimethylene)]bis(oleamide) was determined with non-adapted activated sludge in the Manometric Respirometry Test according to OECD guideline 301 F for a period of 60 days. The test item concentration selected as appropriate was 18 mg/L, corresponding to a ThOD of 51.7 mg O2/L (56.9 mg O2/L with nitrification) per test vessel. The oxygen was depleted by the respiration of bacteria and the degradation was followed by measuring the oxygen concentration. The biodegradation rate is therefore expressed as the percentage BOD (biological oxygen demand) and was calculated for each study day.

The mean oxygen depletion in the inoculum control was 13.9 mg O2/L on day 28 and on day 60 21.5 mg O2/L.

In order to check the activity of the test system sodium benzoate was used as functional control. The pass level > 60% was reached within 3 days. The biodegradation reached a maximum of 89% degradation on day 31.

In the toxicity control containing both test and reference item 52% degradation occurred within 14 days. After 28 days the biodegradation was 73% and after 60 days it came to 87%. The degradation of the reference item was not inhibited by the test item.

The mean of replicates of the test item reached the 10% level (beginning of biodegradation) on day 11 and the 60% pass level was reached on day 32. The mean biodegradation on day 28 was 56% and on day 60 77%. 

The test substance N,N’-[(methylimono)bis(trimethylene)]bis(oleamide) is classified as inherently biodegradable within the 60 day period of the study.