2-(2H-benzotriazol-2-yl)-p-cresol

Biodegradation in water and sediment: simulation tests

Administrative data

Endpoint:

biodegradation in water: sediment simulation testing

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Cross-reference

Reason / purpose for cross-reference:

data waiving: supporting information

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From Jan. 02, 1989 to Feb. 21, 1989

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study design appears to follow OECD guideline 301B (1992). Contains sufficient detail to suggest GLP-like characteristics, but no statement of certification (reasonably thorough description of authors, dates, design, results and interpretation).

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

The volume of the test solution was reduced from 3.0 L to 1.5 L. The CO2 formed by biodegradation was absorbed with NaOH and determined on a carbon analyzer.

GLP compliance:

no

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): Bacteria collected from activated sludge of the sewage treatment plant of CH - 4153 Reinach on 02/01/89
- Preparation of inoculum for exposure: The preparation was carried out according to the method described in the guideline.

Duration of test (contact time):

28 d

Initial conc.:

11 mg/L

Based on:

test mat.

Initial conc.:

20.1 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

Vessels: 2 Liter flasks equipped with gas inlet and magnetic stirrer.
Water: The test medium was prepared according to the method described in the guideline.
Temperature: 22 ± 2ºC
Test substance: 1200 mL of the mineral solution with the inoculum were aerated for 24 hours in the test vessel. In 300 mL mineral solution 0.5 mL Nonylphenol 10EO5PO (solution of 30 mg in 100 mL bidist. water) and 16.5 rsp. 30.2 mg of test substance were added and homogenized. This solution was given to the test vessel which was immediately connected to the CO2 traps.
10 mg test substance are equivalent to 6.93 mg organic carbon, based on the chemical formula.
Reference substance: Aniline, 20 mg/L containing 0.5 mL of the Nonylphenol 10EO5PO solution
Blank: Water as specified in the guideline containing 0.5 mL of the Nonylphenol 10EO5PO solution.

Reference substance:

aniline

Test performance:

There was no method compatible with the requirements of the method available to maintain the substance in suspension. It therefore formed deposits at the glass wall, which could not be brought back into suspension quantitatively. The results may therefore not reflect the real degree of biodegradability.

Parameter:

% degradation (CO2 evolution)

Value:

0

Sampling time:

28 d

Remarks on result:

other: 11 mg test substance/L

Parameter:

% degradation (CO2 evolution)

Value:

2

Sampling time:

28 d

Remarks on result:

other: 20.1 mg test substance/L

Value:

other: not determined

Results with reference substance:

Reference substance: The biodegradation was calculated as: 20 mg/L = 84.3% in 28 days.

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

The substance is not biodegradable in this test.