4,5,6,7-tetrahydro-1H-benzotriazole

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:

2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

4,5,6,7-tetrahydro-1H-benzotriazole

EC Number:

229-858-6

EC Name:

4,5,6,7-tetrahydro-1H-benzotriazole

Cas Number:

6789-99-7

Molecular formula:

C6H9N3

IUPAC Name:

4,5,6,7-tetrahydro-1H-1,2,3-benzotriazole

Details on test material:

Physical state, appearance: solid, white
Storage conditions: room temperature

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source: Activated sludge from a municipal sewage treatment plant, Mannheim, Germany, aeration tank
- Sampling: suitable aliquot of the activated sludge suspension was sieved by a finely woven mesh with a mesh size about 1 mm.
- Cultivation: To reduce the content of inorganic carbon in the blank controls the activated sludge was aerated with carbon dioxide free air for about 24 hours at 22 ± 2° C.
- Preparation for testing: At the day of exposure the suspension was washed one time with drinking water. Therefore, the aeration was stopped and the sludge was allowed to settle. After settling the supernatant was discarded and the remaining sludge suspension was filled up with drinking water and the concentration of the sludge was adjusted to 6.0 g/L dry weight. Aliquots of 7.5 mL were added to the test vessels to obtain an activated sludge concentration of 30 mg/L dry weight.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

20 mg/L

Based on:

TOC

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium: complies with mineral medium in OECD 201B (P 116 mg/L, N 1.3 mg/L, Na 86 mg/L, K 122 mg/L, Mg 2.2 mg/L, Ca 9.9 mg/L, Fe 0.05 - 0.1 mg/L)
- Test temperature: 22+-2°C
- pH: 7.2-7.4
- Suspended solids concentration: 30mg/L


TEST SYSTEM
- Culturing apparatus: 2 L incubation bottles, filled up to a volume of 1.5 L, were connected to two serial scrubbing bottles (total volume 250 mL) filled with 100 mL 0.05 mol sodium hydroxide solution for the adsorption of carbon dioxide from biodegradation processes.
- Number of culture flasks/concentration: 2
- Method used to create aerobic conditions: carbon dioxide free air at a flow of approximately 800 mL per hour.
- Test performed in open system: no


SAMPLING
- Sampling frequency: Twice a week the Total Inorganic Carbon (TIC) values of the adsorption solutions of the first trap were determined and used for the calculation of the produced carbon dioxide. After each sampling the second trap was moved forward and the new trap with fresh sodium hydroxide solution was placed into the second position. Each trap was analyzed separately.


CONTROL AND BLANK SYSTEM
- Inoculum blank: 2
- Toxicity control: 1

Reference substance

Reference substance:

aniline

Results and discussion

% Degradation

Key result

Parameter:

% degradation (CO2 evolution)

Value:

< 10

Sampling time:

28 d

BOD5 / COD results

Results with reference substance:

Degree of biodegradation of the reference substance anailine after 14 days: 82 % CO2/ThCO2

Any other information on results incl. tables

Degree of biodegradation in the inhibition control after 14 days: 40 % CO2/ThCO2

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable