Cyclohexyl(ethyl)amine

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

9.5. – 8.6. 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Cyclohexyl(ethyl)amine

EC Number:

226-733-8

EC Name:

Cyclohexyl(ethyl)amine

Cas Number:

5459-93-8

Molecular formula:

C8H17N

IUPAC Name:

N-ethylcyclohexanamine

Test material form:

other: liquid

Details on test material:

- Name of test material (as cited in study report): N-ethylcyclohexylamine
- Physical state: clear colourless liquid
- Analytical purity: 99.5% (w/w)
- Impurities (identity and concentrations): cyclohexanol 0.22% (w/w), alifatic amines 0.23% (w/w), water 0.07% (w/w)
- Lot/batch No.: 89002001
- Expiration date of the lot/batch: 12/2012
- Storage condition of test material: in original packaging at the fridge

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

sewage, predominantly domestic, non-adapted

Details on inoculum:

INOCULUM
A mixed population of microorganisms obtained from the secondary effluent of the wastewater treatment plant of Pardubice processing predominantly municipal sewage.

PREPARATION OF THE INOCULUM
The fresh collected wastewater was filtered through paper filter. COD was determined and wastewater was aerated till using.

JUSTIFICATION OF THE TEST SYSTEM
The inoculum preparation is in conformity with the recommendations of the test guidelines.

Duration of test (contact time):

0 - 28 d

Initial test substance concentration

Initial conc.:

3.38 - 3.39 mg/L

Based on:

COD

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Mineral medium: preparation of mineral medium in accordance to Method C.4E - Closed Bottle Test, Council Regulation (EC) No. 440/2008, published in O. J. L 142, 2008.
- Inoculated medium: The mineral medium was strongly aerated for 20 min. and let standing for 20 h at the test temperature. The volume of wastewater for the inoculation of mineral medium was chosen 2.0 mL per 1 L of medium. 30 L aerated mineral medium was prepared for the test and before the beginning of the test it was inoculated with 60 mL of modified wastewater. The pH value of medium: 7.4.
- Test temperature: 20+/-1°C
- Illumination: in the dark
- pH adjusted: no

TEST SYSTEM
- Series of bottles for the test:
- 2 x 9 bottles with test substance and inoculated medium
- 2 x 9 bottles with reference substance and inoculated medium for the check of inoculum activity
- 2 x 5 bottles with test and reference substance mixture and inoculated medium for the toxicity test
- 2 x 9 bottles with inoculated medium only for the blank determination

TEST SYSTEM
- Measuring equipment: equipment for the determination of dissolved oxygen

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes, the inoculated mineral medium
- Toxicity control: yes, the test and reference substance mixture

MEASUREMENT:
- analysis for dissolved oxygen by the Winkler method at the zero-time, 3rd, 7th, 10th, 14th, 17th, 21st, 24th and 28th day.

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

% Degradation

Parameter:

% degradation (O2 consumption)

Value:

0.6

Sampling time:

28 d

BOD5 / COD results

BOD5 / COD

BOD5 / COD 1

Parameter:

COD

Value:

200 other: mg.L-1

BOD5 / COD 2

Parameter:

BOD5

Value:

9 other: mg.L-1

Results with reference substance:

COD of reference substance: 1.642 mg.mg-1, biodegradation 87% after 28 days.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

In this 28-day study of ready biodegradability a degradation of 0.6 % of the test substance, N-ethylcyclohexylamine, was attained in the end of study.

Executive summary:

The test substance, N-ethylcyclohexylamine, was tested for the ready biological degradability in Closed Bottle Test.

 

Test performance

The test was performed according to: Method C.4E - Closed Bottle Test, Council Regulation (EC) No. 440/2008, published in O.J.L 142, 2008.

 

The results of biological degradation are related to experimentally determined COD values

of test and reference substance at the beginning of the test.

Owing to the limited water solubility of test substance dosing the dispersion in mineral medium into each bottle was implemented.

Sodium benzoate was used as the reference substance. The dosage was carried out from the stock solution.

COD of the test substance in medium at the beginning of the main test: 3.38 - 3.39 mg.L-1

COD of reference substance in medium at the beginning of the main test: 3.45 mg.L-1

In parallel to the main test the toxicity test was performed.

Based on the test substance contains nitrogen in the chemical composition, the oxidized nitrogen forms were determined and the correction for nitrification was carried out.

The test was performed at temperature of 20 ± 1 °C with the pH values of solutions 7-8 at the beginning of the test.

 

Validity of test

The prescribed validity criteria in the test were fulfilled.

The test substance was not inhibiting for the used inoculum.

Since all criteria of acceptability were met, this study is considered to be valid.