Reaction mass of 2-amino-2-methyl-1-propanol hydrochlorid (3207-12-3) and 2-amino-2-methyl-1-propanol (124-68-5)

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:

from 2018-07-20 to 2018-12-04

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

1

Reference substance name:

(2-hydroxy-1,1-dimethylethyl)ammonium chloride

EC Number:

221-713-5

EC Name:

(2-hydroxy-1,1-dimethylethyl)ammonium chloride

Cas Number:

3207-12-3

Molecular formula:

C4H11NO.ClH

IUPAC Name:

1-hydroxy-2-methylpropan-2-aminium chloride

Test material form:

liquid

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of activated sludge: Secondary effluent freshly obtained from the municipal sewage treatment plant Chandana Complex, Tumkur -572103 in India.
- Pretreatment: The secondary effluent was filtered through a coarse filter paper. The first 200 mL were discarded. The filtrate was kept aerated up to inoculation.
- Preparation of inoculum for exposure: The inoculum was prepared by adding the required amount of activated sludge (Maximum COD 6000 mg/L as per ISO 5815-1:2003(E)) and dilution water (based on the COD) in a cleaned glass beaker.
- Storage conditions: The inoculum was stored at about 20 ± 2 °C.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

250 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: Accoriding to the guideline
- Preparation of inoculum: The inoculum was prepared by adding a volume of 5 mL filtrate of secondary effluent per L dilution water in a cleaned glass beaker.
- Solubilising agent: No
- Test temperature: 22 ± 2 °C
- pH: 7.46
- pH adjusted: No
- Aeration of dilution water: Yes
- Suspended solids concentration: 3.158 g/L
- Continuous darkness: No

TEST SYSTEM
- Culturing apparatus: Standard flask
- Number of culture flasks/concentration:
Replicate 1: Deionised water (300 mL)
Replicate 2, 3 and 4: Test solution based on the preliminary test + 0.6 mL ATU solution + seeded dilution water (up to 300 mL)
Replicate 5: Control solution - Glucose-glutamic acid [6 mL] + 0.6 mL ATU solution + seeded dilution water (up to 300 mL)
Replicate 6: Blank solution - 0.6 mL ATU solution + seeded dilution water (up to 300 mL)
Replicate 7: Reference solution- Solution from the reference item [50 mL] + 0.6 mL ATU solution + inoculum (up to 300 mL)
- Instruments/Equipment Information
Balance
Water Purification System
pH Meter
Aerator
Cleaned Incubation Bottles (rinsed several times with tap water and then by milli-Q water)
Incubator
5 litre amber color culture bottles
Magnetic stirrer
Common Laboratory Glassware
Ultrasonic cleaner
Actual usage of instrument/equipment and its make/model will be documented in the raw data and presented in the study report

CONTROL AND BLANK SYSTEM
- Inoculum blank: Yes
- Abiotic sterile control: Yes
- Toxicity control: Yes

Reference substance

Reference substance:

other: Potassium dichromate

Results and discussion

Preliminary study:

The ThOD of test item was calculated to be 1.40 mg of O2/mg. For the calculation of the ThOD the information of the main component (2-Amino-2-methyl-1-propanol hydrochloride) of the test item was used.

Test performance:

The validity criteria were fulfilled:
All differences of duplicate biodegradation values expressed as mg O2/L were less than 20 % (1.89 %).
After 28 days, the oxygen depletion in the inoculum blank was 0.98 mg O2/L (< 1.5 mg O2/L).
The residual concentrations of oxygen in the test bottles were found to be > 0.5 mg/L at all measurement intervals.
The reference substance (sodium acetate) attained a 65.62 % biodegradation level based on ThOD (> 60 %) within 14 days.
The percentage degradation of the toxicity control attained a maximum of 68.47 % (> 25 %) by 14 days. Therefore the test item was concluded to be non- inhibitory to the microbial inoculum.
The total nitrogen (N) was determined at all the pre-determined intervals. It is concluded that there was no significant increase in Oxidized Nitrogen from the start to end of the experiment.
Since all criteria for acceptability of the test were met, this study was considered to be valid.

% Degradation

Key result

Parameter:

% degradation (CO2 evolution)

Value:

75.65

Sampling time:

28 d

Details on results:

The test item reached a maximum biodegradability of 75.65 % based on ThOD within 28 days of biodegradation exceeding 60 %.The test item is readily biodegradable under the conditions of the closed bottle test according to OECD criteria.

BOD5 / COD results

Results with reference substance:

The reference substance (sodium acetate) attained a 65.62 % biodegradation level (greater than 60 % degradation) within 14 days based on ThOD.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

The test item is readily biodegradable under the conditions of the closed bottle test according to OECD criteria. The test item reached a maximum biodegradability of 75.65 % based on ThOD within 28 days of biodegradation exceeding 60 %.

Executive summary:

The ready biodegradability of the test substance was investigated according to the OECD guideline 301D: Closed bottle test (1992). The biodegradation of the test substance was followed by exposing it in a mineral medium, inoculated with a population of microorganisms from the secondary effluent from the municipal sewage treatment plant Chandana Complex, Tumkur 572103 in India and incubated for 28 days under aerobic conditions in the dark at 20 ± 2 °C. During this period, the biodegradation of the test substance was determined on the basis of the reduction of dissolved oxygen. The ThOD of test item was calculated to be 1.40 mg of O2/mg. For the calculation of the ThOD the information of the main component (2-Amino-2-methyl-1-propanol hydrochloride) of the test item was used. The ThOD of sodium acetate (reference substance) was calculated to be 0.78 mg of O2/mg. The values for the test and reference substances were determined using the molecular formula and the purity of the substances. The reference substance (sodium acetate) attained a 65.62 % biodegradation level (greater than 60 % degradation) within 14 days based on ThOD.

During the study, the determination of oxygen concentrations were performed at the start of the experiment (day 0) and on day 7, 10, 14, 21 and 28. The test item reached a maximum biodegradability of 75.65 % based on ThOD within 28 days of biodegradation exceeding 60 %. Since all criteria for acceptability of the test were met, this study was considered to be valid.