(±)-menthone

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

16-05-2017 - 19-05-2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Experimental test result performed using standard test guidelines

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

GLP compliance:

no

Specific details on test material used for the study:

- Name of test material: (±)-menthone
- Molecular formula: C10H18O
- Molecular weight: 154.2512 g/mol
- Substance type: Organic
- Physical state: Liquid

Analytical monitoring:

not specified

Vehicle:

yes

Details on test solutions:

The stock solution (150 mg/L) was prepared by dissolving colourless liquid in OECD growth medium. The solution was kept in ultrasonic bath for 20 min. It was not possible to prepare homogenous solution of higher concentration. Test solutions of required concentration were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture.

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Common name:
- Strain: 86.81 SAG
- Source (laboratory, culture collection): Institute of botany of the ASCR
- Initial biomass concentration: 5x10(3) cells /ml
- Method of cultivation: No data available

ACCLIMATION - No data available
- Acclimation period:
- Culturing media and conditions (same as test or not):
- Any deformed or abnormal cells observed:

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Remarks on exposure duration:

±1 hour

Post exposure observation period:

No data

Hardness:

No data

Test temperature:

23 ± 2°C

pH:

Without adjustment,
The sample at concentration 150 mg/l: pH= 7.7 did not changed during the test,
Control: pH= 8.1 changed to 7.9 during the test

Dissolved oxygen:

No data

Salinity:

No data

Conductivity:

No data

Nominal and measured concentrations:

0, 30, 45, 67, 100 and 150 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 50 ml Glass vessel
- Type (delete if not applicable): closed (with air permeable stopper)
- Sample volume: 15 ml
- Initial cells density: 5x10(3) cells/ml
- No. of vessels per concentration (replicates): 3

GROWTH MEDIUM
- Standard medium used: yes

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: Continuous
- Light intensity and quality: 6000-8000 lx

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: microscope with counting chamber Cyrus I or electronic particle counter.
- Other: ErC50 was calculated using non-linear regression by the software Prism 4.0

Reference substance (positive control):

yes

Remarks:

Potassium dichromate (K2Cr2O7)

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

172.9 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% CL: 170.7 - 175.1 mg/l

Results with reference substance (positive control):

Results with reference substance valid
- EC50: 0.75 mg/L

Validity criteria fulfilled:

yes

Conclusions:

The median effective concentration (EC50) for the test substance, (±)-menthone, in Desmodesmus subspicatus was determined to be 172.9 mg/L on the basis of effects on growth rate in a 72 hour study.

Executive summary:

Freshwater algal growth inhibition test was carried out on Desmodesmus subspicatus with the substance (±)-menthone according to OECD Guideline 201.

The test substance was dissolved in DMSO/ OECD growth medium and tested at the concentrations 0, 30, 45, 67, 100 and 150 mg/L. Effects on the growth rate of the organism were studied. The median effective concentration (EC50) for the test substance, (±)-menthone, in Desmodesmus subspicatus was determined to be 172.9 mg/L.

This value indicates that the substance is likely to be non-hazardous to aquatic algae and can be considered as not classified as per the CLP criteria.

Description of key information

The median effective concentration (EC50) for the test substance, (±)-menthone, in Desmodesmus subspicatus was determined to be 172.9 mg/L on the basis of effects on growth rate in a 72 hour study.

Key value for chemical safety assessment

EC50 for freshwater algae:

172.9 mg/L

Additional information

In a study conducted by SSS, Freshwater algal growth inhibition test was carried out on Desmodesmus subspicatus with the substance(±)-menthoneaccording to OECD Guideline 201.The test substance was dissolved in DMSO/ OECD growth medium and tested at the concentrations0, 30, 45, 67, 100 and 150 mg/L. Effects on the growth rate of the organism were studied. The median effective concentration (EC50) for the test substance,(±)-menthone, in Desmodesmus subspicatus was determined to be 172.9 mg/L.

This value indicates that the substance is likely to be non-hazardous to aquatic algae and can be considered as not classified as per the CLP criteria.