Dodecamethylenediamine

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:

10. July 2018 - 09. November 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

Qualifier:

according to guideline

Guideline:

EU Method C.4-C (Determination of the "Ready" Biodegradability - Carbon Dioxide Evolution Test)

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Name 1,12-Diaminododecane
Batch no. B1-5-10
Appearance White flakes with different size
Composition 1,12-Diaminododecane, mono-constituent
CAS No. 2783-17-7
EINECS-No. 220-489-6
Molecular formula C12H28N2
Molecular weight 200.36 g/mol
Purity 99.15 %
Homogeneity homogeneous
Vapour pressure unknown
Stability in solvents H2O: unknown; EtOH: unknown; acetone: unknown; CH3CN: unknown; DMSO: unknown
Solubility in solvents H2O: 0.1 – 1 g/L; EtOH: unknown; acetone: unknown; CH3CN: unknown; DMSO: unknown
Expiry date 29. Jan. 2019
Storage Room Temperature (20 ± 5°C)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

Specification
Activated sludge from a biologic sewage treatment plant was used as inoculum. The chosen plant treats mostly domestic sewage.

Source
The sludge was taken from the activation basin of the ESN (Stadtentsorgung Neustadt) sewage treatment plant, Im Altenschemel, 67435 NW-Lachen-Speyerdorf.
Date of collection: 17. Aug. 2018, batch no: 20180817.
Pre-Treatment
The sludge was filtrated, washed with test medium (2x) and re-suspended in test medium. It was then aerated until use. The dry matter was determined to contain 5000 mg of sus-pended solids/L.

Duration of test (contact time):

28 d

Initial conc.:

>= 27.7 - <= 27.9 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

Preparations
The medium was prepared from the stock solutions. The stock solution of the positive control was prepared and its DOC was measured. The inoculum was taken from its source, washed, aerated and the dry matter was determined.
The test vessels were filled with medium and inoculum. Then, all flasks were aerated for 72 hours with purified, CO2-free, moistened air to purge the system of CO2.
Experimental Parameters
Flask volume 1500 mL
Apparatus blanks 2, containing mineral medium only
Blank Controls 2, containing mineral medium and inoculum
Positive control flasks 2, containing positive control, mineral medium and inoculum
Test flasks 2, containing test item, mineral medium and inoculum
Abiotic control 1, containing test item, mineral medium and HgCl2
Toxicity control 1, containing test item, positive control, mineral medium and in-oculum
Inoculum concentration: 25.0 mg/L
Temperature 19.7 – 21.9 °C without direct lighting
Duration 28 days
The test was performed with a nominal start concentration of 20 mg organic carbon/L of the test item.

Reference substance:

aniline

Test performance:

All validity parameters and values are considered valid:
Parameter Criterion Found Assessment
IC content of test item solution in medium < 5% of TC 0 % valid
CO2 emitted by the controls < 70 mg/L 11.8 mg/L valid
Difference within replicates < 20% 0 % valid
Degradation of positive control > 60% ≤ 14 days 8 days valid
Degradation in the toxicity flask on day 14 > 25% 51.6 % non - toxic

Key result

Parameter:

% degradation (CO2 evolution)

Value:

85

Sampling time:

28 d

Details on results:

The 10-day-window began on day 6, at its end, 59 % mean degradation were reached, missing the pass level of 60 % given in the OECD guideline. At the end of the 10-day-window one replicate surpassed the criterion of 60 %. Degradation of the second rep-licate was slightly below the pass level (58 %). However, the second replicate sur-passed the pass level on the next day. At the end of the test both replicates showed identical degradation of 85 %.
Therefore, in spite of the slight delay in degradation of the second replicate, it can be assumed that the test item 1,12-Diaminododecane is readily biodegradable following OECD 301B and EU C.4-C respectively

The abiotic degradation reached 3.9 %.

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

it can be assumed that the test item 1,12-Diaminododecane is readily biodegradable following OECD 301B and EU C.4-C respectively

Executive summary:

The test item 1,12-Diaminododecane was tested using a concentration of nominally 20 mg organic carbon/L 1,12-Diaminododecane in test medium following OECD 301B and EU-Method C.4-C.

Aniline was chosen as positive control.

Activated sludge was used as inoculum (concentration in the test 25.0 mg dry matter/L). The test was left running for 28 days.

All validity criteria were met. Degradation of the positive control surpassed the pass level of 60 % after 8 days.

The following data were determined for the test item 1,12-Diaminododecane:

10-day-window: day 6 – 16 degradation at the end of 10-day-window *59 % degradation at the end of the test 85 % pass level following guideline: 60 % at the end of 10-day-window for pure substances

respective 60 % at the end of the test for mixtures

*At the end of the 10-day-window one replicate surpassed the criterion of 60 %. Degradation of the second replicate was slightly below the pass level (58 %). The mean degradation of both replicates at the end of the 10-day window was 59 %. However, the second replicate surpassed the pass level on the next day. At the end of the test both replicates showed identical degradation of 85 %.

Therefore, in spite of the slight delay in degradation of the second replicate, it can be as-sumed that the test item 1,12-Diaminododecane is readily biodegradable following OECD 301B and EU C.4-C respectively

Description of key information

Study on Ready-biodegradability available.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Type of water:

freshwater