Geranyl butyrate

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:

09.06.2017 - 12.06.2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Experiment test result performed using standard test guideline

Justification for type of information:

Data is from ABITEC lab report

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Principles of method if other than guideline:

Short term toxicity of Geranyl butyrate to aquatic algae was performed according to the 201 OECD guideline in a static system.

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of test material (as cited in study report): Geranyl butyrate
- Molecular formula (if other than submission substance): C14H24O2
- Molecular weight (if other than submission substance): 224.342 g/mol
- Smiles notation (if other than submission substance): C(=C\COC(CCC)=O)(\CC\C=C(\C)C)C
- InChI: 1S/C14H24O2/c1-5-7-14(15)16-11-10-13(4)9-6-8-12(2)3/h8,10H,5-7,9,11H2,1-4H3/b13-10+
- Substance type: Organic

Analytical monitoring:

not specified

Vehicle:

yes

Details on test solutions:

The stock solution (200 g/L) was prepared by dissolving colourless liquid in acetone. 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

Test temperature:

23±2°C

pH:

Test at highest concentration 117 mg/l: 7.9 (no change during tests)
Control: 8.0 (changed to 7.7 during test)
Control + acetone: 8.0 change to 7.6 during the test

Nominal and measured concentrations:

0, 0, 33, 50, 75, 113, 170 mg/l nominal concentration

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:

other: ErC50

Effect conc.:

100.3 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95 % CI was 83.1 - 121.5 mg/l

Results with reference substance (positive control):

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

Reported statistics and error estimates:

ErC50 was calculated using non-linear regression by the software Prism 4.0

Validity criteria fulfilled:

not specified

Conclusions:

The median effective concentration (EC50) for the test substance Geranyl butyrate, in Desmodesmus subspicatus was determined to be 100.3 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 Geranyl butyrate. Test was performed according to OECD Guideline 201.

The stock solution (200 g/L) was prepared by dissolving colourless liquid in acetone. Test solutions of required concentration were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture. Substance tested at the 0, 0, 33, 50, 75, 113, 170 mg/l nominal concentration. Effects on the growth rate of the organism were studied.

The median effective concentration (ErC50) for the test substance Geranyl butyrate, in Desmodesmus subspicatus was determined to be 100.3 mg/L with 95% CI was 83.1 - 121.5 mg/l.

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

Description of key information

Freshwater algal growth inhibition test was carried out on Desmodesmus subspicatus with the substance Geranyl butyrate. Test was performed according to OECD Guideline 201. The stock solution (200 g/L) was prepared by dissolving colourless liquid in acetone. Test solutions of required concentration were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture. Substance tested at the 0, 0, 33, 50, 75, 113, 170 mg/l nominal concentration. Effects on the growth rate of the organism were studied. The median effective concentration (ErC50) for the test substance Geranyl butyrate, in Desmodesmus subspicatus was determined to be 100.3 mg/L with 95% CI was 83.1 - 121.5 mg/l.

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

Key value for chemical safety assessment

EC50 for freshwater algae:

100.3 mg/L

Additional information

Various studies including experimental data for the target chemical Geranyl butyrate (CAS No. 106 -29 -6) and the study for its read across substance were reviewed to summarize the following information:

In a first key study for the target chemical was taken from the ABITEC report, 2017. Freshwater algal growth inhibition test was carried out on Desmodesmus subspicatus with the substance Geranyl butyrate. Test was performed according to OECD Guideline 201. The stock solution (200 g/L) was prepared by dissolving colourless liquid in acetone. Test solutions of required concentration were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture. Substance tested at the 0, 0, 33, 50, 75, 113, 170 mg/l nominal concentration. Effects on the growth rate of the organism were studied. The median effective concentration (ErC50) for the test substance Geranyl butyrate, in Desmodesmus subspicatus was determined to be 100.3 mg/L with 95% CI was 83.1 - 121.5 mg/l. This value indicates that the substance is likely to be non-hazardous to aquatic algae and cannot be classified as toxic as per the CLP criteria.

 

A 72 h algae inhibition test was conducted according to the OECD Guideline 201 (Alga, Growth Inhibition Test) (A.M. Api, et. al; 2015). Based on the effect on growth rate of the test organism, the 72 hrs EC50 value was determined to be 110 mg/l, respectively. Thus, based on the EC50 value, it can be concluded that the read across substance Benzyl acetate (CAS no. 140-11-4) can be considered as non-toxic to aquatic organisms and thus cannot be classified as hazardous as per the CLP criteria.

 

Similarly study was also conducted on the read across chemical (28553 -12 -0). Short term toxicity to Selenastrum capricornutum (green algae) study was carried for 96 hrs (William J. Adams, et. al; 1995). Phthalate ester test solutions were prepared by mixing the appropriate amount of test chemical with the algal growth medium and stirring for 1 hr to provide the highest test concentration. Dilutions of this concentrations were made to provide additional test concentrations. Test organism used for the study was Selenastrum capricornutum. Test organism was acclimated to the appropriate temperature before being tested. The study was based on the effects of the test compound on Selenastrum capricornutumin a static fresh water system. Study was performed at a constant light intensity of 60 to 70.5µE/m2s and at a temperature and pH of 22 - 24°C and 7.6 -7.9, respectively. Range finding tests were performed using the test chemical to determine the concentration range to test for each test organism. If the range-finding test indicated that toxicity would occur at a concentration below the water solubility of the test chemical, definitive test were done using five concentrations and a control. If the range-finding test indicated that no toxicity would occur at levels upto the water solubility of the chemical, a test with a single concentration was performed at or near the water solubility limit of the chemical. Temperature was maintained in all tests by a temperature-controlled waterbath to within ± 1°C. Each test vessel was placed on an orbital shaker for the duration of the experiment, and algal assays continued until there was less than 5% change in the daily in vivo chlorophyll-a measurements for a maximum of 10 d. Cell counts were performed at the end of the tests. EC50 value was calculated using a standard computerized approach that incorporated the moving average, binomial, and probit methods. The method that provided the best data fit and smallest 95% confidence interval was used to calculate the reported values. For analytical measurements, the stock solutions prepared for each test concentration was sampled in duplicate before it was poured into the test vessels. At the end of the study, replicate test solutions were combined and duplicate samples were analyzed. Samples were extracted three times with 50 ml of hexane for 2 to 3 mns. Extracts were combined and the volume was reduced using a Kuderna-Danish® apparatus. The final concentrate was stored in a 10-ml serum vial at 0° until the analysis was performed. Sample extracts were analyzed by gas chromatography (GC). Typically, the following instruments and conditions were used: Hewlett-Packard models 5880 and 5840 and Perkin-Elmer model 3920 columns: 6’ × 0.25’’ (o. d.) × 2 mm (i. d.); column packing was either 3% OV-210 on 100/120 Chromsorb WHP; or 3% OV-1 on 100/120 Gas Chrom Q. the carried gas was 95% argon and 5% methane; the injection volume was 2 to 3µl when automated or 3 to 5µl manual; and the detector was an electron capture detector. Injector column, and detector temperatures varied from 165 to 350°C, depending on the test chemical. Based on the cell count of the test organism Selenastrum capricornutum (green algae), the 96 hr EC50 value was determined to be > 1.8 mg/l, respectively. Thus, based on this value, it can be concluded that the substance Diisononyl phthalate can be considered as toxic to aquatic organisms and thus can be classified as aquatic chronic category 2. Since the chemical is readily biodegradable in nature, Diisononyl phthalate can be considered as non-toxic to aquatic organisms and thus cannot be classified as hazardous as per the CLP criteria.

 

Based on the overall reported results for target and its read across substance, it can be concluded that the test substance Geranyl butyrate can be considered as non-toxic to aquatic organisms and thus cannot be classified as hazardous as per the CLP criteria.