4-(2,5,6,6-tetramethylcyclohex-2-enyl)but-3-en-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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1997

Report date:

1997

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Test guideline 2

Qualifier:

according to guideline

Guideline:

ISO 8692 (Water Quality - Fresh Water Algal Growth Inhibition Test with Scenedesmus subspicatus and Selenastrum capricornutum)

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: EEC Directive 92/69/EEC L383A Methods for the Determination of Ecotoxicity. Algal Inhibition test.

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

3-methyl-4-(2,6,6-trimethyl-2-cyclohexen-1-yl)-3-buten-2-one

EC Number:

204-846-3

EC Name:

3-methyl-4-(2,6,6-trimethyl-2-cyclohexen-1-yl)-3-buten-2-one

Cas Number:

127-51-5

Molecular formula:

C14H22O

IUPAC Name:

3-methyl-4-(2,6,6-trimethylcyclohex-2-en-1-yl)but-3-en-2-one

Specific details on test material used for the study:

Name: Methyl ionone alpha iso 60
Chemical Name: 4-(2,6,6,-trimethyl-3-cyclohexen-1-yl)3-methyl-3-buten-2-one
CAS No.: 127-51-5
Appearance: Pale yellow liquid
Storage: Room temperature, dark

Test solutions

Vehicle:

not specified

Test organisms

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

Scenedesmus subspicatus is widely distributed in freshwaters and is easily maintained in laboratory culture in synthetic media. It is one of two species used in the ISO algal growth inhibition test and is recommended of use in algal growth inhibition tests in OECD Guideline 201 and EEC Directive 92/69/EEC L383A.

Study design

Water media type:

freshwater

Total exposure duration:

72 h

Test conditions

Test temperature:

Test area temperature: 23 - 25 °C

pH:

The pH of the test media were determined at 0 and 72 hours.
Test media pHs at 0 hours 7.0 - 7.6
Test media pHs at end of test 7.6 - 9.7

Nominal and measured concentrations:

Nominal test concentrations: 0, 5.6, 10, 18, 32 and 56 mg/l
Geometric mean of the measured concentrations: 0.49, 0.61, 1.1, 2.3, 5.1 mg/l

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 5.1 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 2

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

2.3 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 3

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

4.4 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Effect concentrations 4

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

2.3 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The toxicity of Methyl Ionone Alpha ISO 60 to the freshwater geen alga Scenedesmus subspicatus was determined in compliance with ISO, OECD and EEC methods.

72 hour EC50 (growth rate): > 5.1 mg/l
72 hour NOEC (growth rate): 2.3 mg/l