1,1,2,3,3,6-hexamethylindan-5-yl methyl ketone

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

other: NEN 6515: Water-Repetitve biodegradability test of organic compounds (1989)

GLP compliance:

yes

Specific details on test material used for the study:

- Appearance: White crystalline solid

Oxygen conditions:

aerobic

Inoculum or test system:

sewage, predominantly domestic, non-adapted

Details on inoculum:

Inoculum: Activated sludge sampled at De Bilt municipal sewage plant 21-02-1991
Inoculum addition: 10 mL of activated sludge, corrected to 2 g/L dry substance, per liter of test medium
Incubation temperature: 20±1.5°C

Duration of test (contact time):

49 d

Initial conc.:

22.2 mg/L

Based on:

other: ThOC

Parameter followed for biodegradation estimation:

O2 consumption

Reference substance:

acetic acid, sodium salt

Test performance:

Oxidation of sodium-acetate: After 1 week 68% (required >60%) and after 4 weeks 69% (required <100%)
Oxidation consumption in the blanks: In the first week 1.2 mg (required <3mg) and in the next weeks 0.5-1.1 mg (required <1 mg)
Oxygen contents in reference test bottles (sodium acetate); apreading in triplicate values: 0-0.8 mg/L (required <1 mg/L)

Key result

Parameter:

% degradation (O2 consumption)

Value:

13

Sampling time:

28 d

Parameter:

% degradation (O2 consumption)

Value:

17

Sampling time:

49 d

Details on results:

Toxicity check-ups show the absence of any toxicity of the test substance to the inoculum: Mean oxygen content in the reference (week 1) was 4.5 mg/L and the in the toxicity bottles 4.3 mg/L

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Description of key information

The test substance is considered to be not readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Type of water:

freshwater

Additional information

The biodegradability of the test substance was tested in a ready biodegradation test performed in accordance with NEN 6515: Water Repetitive biodegradability test of organic compounds (1989) and following GLP. Inoculum from a municipal sewage treatment plant was used. Sodium acetate was used a positive control. The toxicity test showed that the test substance was not toxic to the inoculum. The validation criteria were met. Under the chosen conditions, 13% of the test substance was degraded within 28 days.