4-(2,6,6-trimethyl-1-cyclohexen-1-yl)butan-2-one

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

December 2016 - January 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 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

4-(2,6,6-trimethyl-1-cyclohexen-1-yl)butan-2-one

EC Number:

241-318-1

EC Name:

4-(2,6,6-trimethyl-1-cyclohexen-1-yl)butan-2-one

Cas Number:

17283-81-7

Molecular formula:

C13H22O

IUPAC Name:

4-(2,6,6-trimethyl-1-cyclohexen-1-yl)butan-2-one

impurity 1

Reference substance name:

rel-4-((1R,6R)-2,2,6-trimethylcyclohexyl)butan-2-one

Cas Number:

60761-23-1

Molecular formula:

C13H24O

IUPAC Name:

rel-4-((1R,6R)-2,2,6-trimethylcyclohexyl)butan-2-one

Test material form:

liquid

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

Samples from the test solutions were analysed to determine actual levels of the test item at start of the exposure period (time 0) and following 72 hours of exposure. At time 0 hours the measured concentrations range between 87-114% of the expected concentrations following dilution of the water saturated solution. After 72 hours exposure, the test concentrations remained stable at between 80-103% of the time 0 hours starting concentration. Therefore, the test item concentration based on initial measured concentration remained stable within ±20% throughout the exposure period.

Test solutions

Vehicle:

no

Details on test solutions:

The study was conducted under static conditions; i.e., the test solutions were not renewed during the test.

Test organisms

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

Test temperature:

21.0-22.1, mean 21.54 °C; for details see section 18.1 in the attached report

pH:

8.3 in the test medium
8.2-9.2 in the test solutions

Reference substance (positive control):

yes

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

3.38 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

cell number

Effect concentrations 2

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.275 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

cell number

Effect concentrations 3

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

0.187 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

cell number

Effect concentrations 4

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

10 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 5

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

4.73 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 6

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

2.48 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

growth rate

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Executive summary:

The EC50 based on YIELD of Pseudokirchneriella subcapitata was determined to be 9.58% of a saturated solution at a loading of 100 mg/L, equivalent to 3.38 mq Dihvdro lonone Beta/L based on measured concentrations.

The NOEC for YIELD based on nominal concentration was 0.874 % of a saturated solution at a loading of 100 mg/L, equivalent to 0.275 Mg Dihydro lonone Beta/L based on measured concentrations.

The EC50 based on GROWTH RATE of Pseudokirchneriella subcapitata was determined to be 29.0% of a saturated solution at a loading of 100 mg/L, equivalent to 10.0 mg Dihvdro lonone Beta/L based on measured concentrations.

The NOEC for GROWTH RATE based on nominal concentration was 6.61 % of a saturated solution at a loading of 100 mg/L, equivalent to 2.48 Mg Dihydro lonone Beta/L based on measured concentrations.