6-methyloct-5-en-2-one

Toxicity to microorganisms

Administrative data

Endpoint:

activated sludge respiration inhibition testing

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP Guideline study, test was performed with sludge from municipal waste water treatment plant

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1995

Report date:

1995

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

6-methylhept-5-en-2-one

EC Number:

203-816-7

EC Name:

6-methylhept-5-en-2-one

Cas Number:

110-93-0

IUPAC Name:

6-methylhept-5-en-2-one

Details on test material:

- Name of test material (as cited in study report): 2-methylhepten-2-on-6
- Lot/batch No.: 94-1739
- Analytical purity: > 98 %
- Impurities (identity and concentrations): 2-methyl-2-hepten-6-ol: < 1%

Sampling and analysis

Analytical monitoring:

no

Test organisms

Test organisms (species):

activated sludge, domestic

Details on inoculum:

Test mixture contained test substance (1g/l), sewage feed (as prescribed by OECD 209) and activated sludge from laboratory wastewater treatment plants treating municipal wastewater.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

30 min

Test conditions

Nominal and measured concentrations:

- Test concentrations (mg/L): 20, 100, 250, 500, 1000 (nominal)

Details on test conditions:

TEST CONDITIONS
Test mixture (total volume 250 ml) was incubated at 20+/-2°C for 30 minutes, after which the respiration rate was measured.

TEST SYSTEM
The following controls were included:
- Inoculum blank: control without test substance but with inoculum (3 flasks)
- Positive control: with inoculum (3 flasks, 1, 10, and 100 mg/l).

Reference substance (positive control):

yes

Remarks:

3,5-dichlorophenol

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

30 min

Dose descriptor:

other: EC20

Effect conc.:

ca. 27 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Effect concentrations 2

Duration:

30 min

Dose descriptor:

EC50

Effect conc.:

800 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Details on results:

Respiration rate
Test substance Inhibition (mgO2/l*h) Inhibition (%)
20 mg/l 13 -19
100 mg/l 12 -25
250 mg/l 11 -31
500 mg/l 10 -38
1000 mg/l 7 -56

Results with reference substance (positive control):

Respiration rate
Reference substance Inhibition (mgO2/l*h) Inhibition (%)
1 mg/l 15 -6
10 mg/l 9 -44
100 mg/l 1 -94

The EC20 for the reference 3,5-dichlorophenyl was 2.5 mg/l and the EC50 was 15 mg/l. The EC50 for the reference is valid because of ranging between 5 and 30 mg/l as validity criteria.