Amides, C12-18(even numbered), N-[3-(dimethylamino)propyl]

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

25.08.2008-22.09.2008

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study. The chemical structure of the individual constituents of the supporting substance is the same, the carbon chain length distribution is very similar.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Report date:

2008

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Principles of method if other than guideline:

Deviating from the study plan additional inoculum blank assays had to be analysed due to variations in the 10 d-window between the two test item concentrations applied. These additional vessels were started originally as spare vessels.

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Amides, C8-18 even numbered, N-[3-(dimethylamino)propyl]

EC Number:

930-947-3

IUPAC Name:

Amides, C8-18 even numbered, N-[3-(dimethylamino)propyl]

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): Fresh samples of activated sludge were withdrawn on August 25th, 2008 from the sewage treatment plant in Schmallenberg (Germany) which is mainly fed with municipal wastewater.
- Laboratory culture: no
- Preparation of inoculum for exposure: The samples were washed once with mineral medium after the arrival at the laboratory and kept aerobic until use.
- Pretreatment: no
- Concentration of sludge: 29.5 mg dry mass/L
- Water filtered: not reported (deionized water, free from inhibitory concentration of toxic substances)

Duration of test (contact time):

28 d

Initial test substance concentration

Initial test substance concentration 1

Initial conc.:

25 mg/L

Based on:

test mat.

Initial test substance concentration 2

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: mineral medium according to guideline
- Additional substrate: no
- Solubilising agent (type and concentration if used): no
- Test temperature: 22°C
- pH: Initial pH adjusted to 7.4 +/- 0.2; at the end of the test the pH values of all solutions were determined. They were in the range between 7.5 and 7.7 in all test vessels.
- pH adjusted: yes
- Aeration of dilution water: not reported
- Suspended solids concentration: 29.5 mg/L
- Continuous darkness: yes

TEST SYSTEM
- Culturing apparatus: Sapromat
- Number of culture flasks/concentration: 5 until the end of the 10 d-window, thereafter 2
- Method used to create aerobic conditions: The activated sludge was kept in aerobic condition until use. The test vessels were aerated during the whole test.
- Measuring equipment: Sapromat respirometer (VOITH Inc.)
- Test performed in closed vessels: yes
- Details of trap for CO2 and volatile organics if used: Evolved carbon dioxide was absorbed in a suitable absorbent (not further specified)

SAMPLING
- Sampling frequency: daily
- Sample storage before analysis: no

CONTROL AND BLANK SYSTEM
- Inoculum blank: performed
- Abiotic sterile control: performed
- Toxicity control: performed
- Other: functional/procedural control (reference substance) performed

Reference substance

Reference substance:

benzoic acid, sodium salt

Remarks:

(100 mg/L)

Results and discussion

Test performance:

The ready biodegradability of Tego Amid CNF was determined in a study conducted according to OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test) and EU Method C.4-D (Determination of the "Ready" Biodegradability - Manometric Respirometry Test).

% Degradation

% Degradation 1

Parameter:

% degradation (O2 consumption)

Value:

ca. 23

Sampling time:

2 d

Remarks on result:

other: 25 mg/L test item

% Degradation 2

Parameter:

% degradation (O2 consumption)

Value:

ca. 67

Sampling time:

12 d

Remarks on result:

other: 25 mg/L test item

% Degradation 3

Parameter:

% degradation (O2 consumption)

Value:

81

Sampling time:

28 d

Remarks on result:

other: 25 mg/L test item

% Degradation 4

Parameter:

% degradation (O2 consumption)

Value:

ca. 14

Sampling time:

4 d

Remarks on result:

other: 100 mg/L test item

% Degradation 5

Parameter:

% degradation (O2 consumption)

Value:

57

Sampling time:

28 d

Remarks on result:

other: 100mg/L test item

BOD5 / COD results

Results with reference substance:

The reference item sodium benzoate was biodegraded by 90% after 14 days and thus fulfilling the guideline requirements.

Any other information on results incl. tables

The ready biodegradability of Tego Amid CNF was determined in a study conducted according to OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test) and EU Method C.4-D (Determination of the "Ready" Biodegradability - Manometric Respirometry Test). Tego Amid CNF proved to be readily biodegradable at a test substance concentration of 25 mg/L (81% biodegradation after 28 d). At a concentration of 100 mg/L, the test substance was biodegraded by 57% after 28 d; thus, the pass level of 60% biodegradation was not reached. However, due to the high ThOD of 2.73 mg O2/mg test substance, the test item suspension with a concentration of 25 mg/L met the criteria of 50 -100 mg ThOD or COD/L as demanded in the guideline. No significant nitrification was observed until test end (at most 7.6% of theoretical NO3 production in the higher concentrated assay). No abiotic degradation of Tego Amid CNF was observed. The reference item sodium benzoate was biodegraded by 90% after 14 days and thus fulfilling the guideline requirements. In the toxicity control (100 mg/L test and reference substance each) the biodegradation amounted to 62% after 14 d. Thus, the test item can be considered as non toxic to the inoculum. The oxygen uptake of the inoculum blank was < 60 mg/L in 28 d and the pH was inside the range of 6.0 -8.5. The difference of extremes of replicate values of the removal of the test item at the end of the test was less than 20%.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

Tego Amid CNF proved to be readily biodegradable (81% biodegradation after 28 d) in a study conducted according to OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test) and EU Method C.4-D (Determination of the "Ready" Biodegradability - Manometric Respirometry Test).

Executive summary:

The ready biodegradation of Tego Amid CNF was investigated in a study conducted according to OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test) and EU Method C.4-D (Determination of the "Ready" Biodegradability - Manometric Respirometry Test) over a period of 28 days and using domestic activated sludge as inoculum. The biodegradation rate was determined by measurement of oxygen consumption. Inoculum blank, abiotic control, procedural/functional control with the reference substance sodium benzoate, and toxicity control using 100 mg/L test item and 100 mg/L reference compound were performed.

This study is regarded as reliable without restriction and satisfies the guideline requirements for ready biodegradation.

The test item proved to be readily biodegradable and fulfilling the 10-d window criterion. The functional control reached the pass level >60% after 14 d. In the toxicity control containing both test and reference item 62% biodegradation based on oxygen consumption occurred within 14 d thus indicating that the test item was not inhibitory to the inoculum at the concentrations tested.