1,1,3-trimethylindan-4-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:

22.06.2020 - 17.09.2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Title:

Unnamed

Year:

2020

Report date:

2020

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

1,1,3-trimethyl-2,3-dihydro-1H-inden-4-amine

EC Number:

838-724-1

Cas Number:

94568-76-0

Molecular formula:

C12H17N

IUPAC Name:

1,1,3-trimethyl-2,3-dihydro-1H-inden-4-amine

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

Aerobic activated sludge, microorganisms from a domestic waste water treatment plant was supplied by the sewage treatment plant Rossdorf, Germany.
Conditioning:
The aerobic activated sludge used for this study was deposited for 45 min, washed by centrifugation and the supernatant liquid phase was decanted. The solid material was re-suspended in test water and centrifuged again. This procedure was done three times. An aliquot of the final sludge suspension was weighed, dried and the ratio of wet sludge to its dry weight was determined. Based on this ratio, calculated aliquots of washed sludge suspension, corresponding to 3.5 g dry material perlitre were mixed with test water and aerated overnight. This suspension was used for the experiment.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

100 mg/L

Based on:

ThOD

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

Type and Size:
Manometric Test System with test flasks containing a volume of approximately 500 mL.
Apparatus: BSB/BOD-Sensor-System
Principle:
The test flasks prepared according paragraph 6.6 were incubated at 22°C * 1°C. The pressure decrease in the reaction vessels was measured over complete experimental phase of 28 days using theBSB/BOD-Sensor-System. The test flasks were closed gas-tight by a measuring head. Potassium hydroxide solution (45%) was used for trapping the produced carbon dioxide. The amount of O2
consumed by the activated sludge was calculated from the decrease of pressure in the reaction vessel.
Identification:
Each test unit was uniquely identified with the study number, treatment and replicate number.
Surrounding Type: Climatised chamber
Temperature: 22°C ± 1°C
Light Conditions: Darkness
pH-Value of Test Solutions: 7.3 to 7.5 (measured at the start of the test, pH in test vessels were adjusted to 7.5)
7.2 to 8.2 (measured at the end of the test)
Recording: Test conditions (temperature) were recorded continuously with suitable instruments, documented in the raw data and reported in the final report. (Short-term deviations (< 2 hours) from the recommended temperature range do normally not result in major disturbances of the test performance and were not reported.)
Reconstituted Test Water: Analytical grade salts were added to pure water to prepare the following stock solutions:
a) 8.5 g KH2PO4, 21.75 g K2HPO4, 33.4 g Na2HPO4 x 2 H2O, 0.5 g NH4Cl filled up with pure water to 1000 mL volume; The pH-value was 7.4.
b) 11.25 g MgSO4 x 7 H2O filled up with pure water to 500 mL volume
c) 18.2 g CaCl2 x 2 H2O filled up with pure water to 500 mL volume
d) 0.125 g FeCl3 x 6 H2O filled up with pure water to 500 mL volume
In order to avoid precipitation of iron hydroxide in the stock solution d), one drop of concentrated HCl per litre was added before storage.
50 mL of stock solution a) and 5 mL of the stock solutions b) to d) were combined and filled up to a final volume of 5000 mL with pure water.
The pH was adjusted to pH 7.5 with 1M HCL solution.

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

% Degradation

Key result

Parameter:

% degradation (CO2 evolution)

Value:

0

Sampling time:

28 d

Remarks on result:

other: not readily biodegradable

Details on results:

Nitrogen is part of the molecular structure of the test item; therefore the evaluation of biodegradation has to be based on ThODNH4 and ThODNO3. The criterion for ready biodegradability under the conditions of a manometric respirometry test is the degradation of the test item of at least 60%, reached within a 10-day window; the 10-day window starts when the degradation of the test item reaches at least 10% degradation.

The test material never reached a mean biodegradation of 10% during the incubation period. The mean biodegradation at test end after 28 days was 0% (ThODNH4, ThODNO3).
Therefore, the test material is considered to be not readily biodegradable based on ThODNH4 and ThODNO3.

BOD5 / COD results

Results with reference substance:

The reference item sodium benzoate was sufficiently degraded to 82% after 14 days and to 88% after 28 days of incubation, thus confirming the suitability of the aerobic activated sludge inoculum used.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

The test material never reached a mean biodegradation of 10% during the incubation period. The mean biodegradation at test end after 28 days was 0% (ThODNH4, ThODNO3).

Executive summary:

Biodegradation of BCS-AF93710:	Nitrogen is part of the molecular structure of the test item; therefore the evaluation of biodegradation has to be based on ThODNH4 and ThODNO3. The criterion for ready biodegradability under the conditions of a manometric respirometry test is the degradation of the test item of at least 60%, reached within a 10-day window; the 10-day window starts when the degradation of the test item reaches at least 10% degradation.   BCS-AF93710 never reached a mean biodegradation of 10% during the incubation period. The mean biodegradation at test end after 28 days was 0% (ThODNH4, ThODNO3). Therefore, BCS-AF93710 is considered to be not readily biodegradable based on ThODNH4 and ThODNO3.
Biodegradation of Sodium Benzoate:
Biodegradation of the Toxicity Control:	In the toxicity control containing both, the test item and the reference item sodium benzoate, 27% (ThODNH4) biodegradation was noted within 14 days and after 28 days of incubation (25% based on ThODNO3). Accordi The reference item sodium benzoate was sufficiently degraded to 82% after 14 days and to 88% after 28 days of incubation, thus confirming the suitability of the aerobic activated sludge inoculum used. According to the test guidelines, the test item can be assumed to be not inhibitory to the aerobic activated sludge microorganisms because degradation was >25% within 14 days.