Ethyl (2E,4Z)-2,4-decadienoate

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:

Feb. 5-13, 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Ethyl (2E,4Z)-2,4-decadienoate

EC Number:

221-178-8

EC Name:

Ethyl (2E,4Z)-2,4-decadienoate

Cas Number:

3025-30-7

Molecular formula:

C12H20O2

IUPAC Name:

ethyl deca-2,4-dienoate

Test material form:

not specified

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Bedoukian Research, Inc., Lot number 2017331-0025
- Expiration date of the lot/batch: May 27, 2020

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Refrigerated, then frozen.
- Stability under test conditions: not stable
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium:

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: all
- Sampling method: Sampling was performed at 0 and 96 hrs. Samples taken at 0 hrs were taken prior to test medium distribution to test chambers. The 96 hr samples were obtained from pooled samples from each test concentration. 10 mL of test solution was taken, and 10 mL of 0.2% formic acid in methanol was added. Samples were then further diluted by a factor of 2.00 by adding 0.2% phosphoric acid in methanol. Samples were then diluted to the analytical range using 50 methanol: 50 freshwater AAP medium: 0.1 phosphoric acid solution.
- Sample storage conditions before analysis: Additional samples were taken and refrigerated for possible future analysis.

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: 0.0160 g of test substance was added to 4000 mL of water, then sonicated for 20 minutes and then stirred for 20 minutes. The solution was then inverted 20 times. Further concentrations of the test substance was made by taking aliquots and further diluting them with AAP medium.
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): No

Test organisms

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Source (laboratory, culture collection): University of Texas at Austin


ACCLIMATION
- Acclimation period: at least two weeks
- Culturing media and conditions (same as test or not): same

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Test conditions

Test temperature:

23.87-24.12 degrees C

pH:

7.3-10.0

Nominal and measured concentrations:

Nominal Measured
0 < LOQ
0.041 mg a.i./L 0.019 mg a.i./L
0.10 mg a.i./L 0.028 mg a.i./L
0.26 mg a.i./L 0.049 mg a.i./L
0.64 mg a.i./L 0.074 mg a.i./L
1.6 mg a.i./L 0.12 mg a.i./L
4.0 mg a.i./L 0.18 mg a.i./L

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Material, size, headspace, fill volume: glass, 250 mL, 100 mL
- Renewal rate of test solution (frequency/flow rate): Test vessels were shaken continuously at 100 rpm
- Initial cells density: 10,000 cells/mL

GROWTH MEDIUM
- Standard medium used: yes, AAP medium

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: NANOPure water


OTHER TEST CONDITIONS
- Adjustment of pH: yes
- Photoperiod: 24 hrs
- Light intensity and quality: 6000 lux


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: electronic particle counter, every 24 hrs


TEST CONCENTRATIONS
- Range finding study
- Test concentrations: 0, 0.086,0.86, 8.6 mg/L
- Results used to determine the conditions for the definitive study: percent inhibition: 0%, 7%, 55%, >99%

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

0.13 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

act. ingr.

Basis for effect:

growth rate

Remarks on result:

other: 95% CI: 0.13-0.14 mg a.i./L

Effect concentrations 2

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.074 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

act. ingr.

Basis for effect:

growth rate

Effect concentrations 3

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

0.17 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

act. ingr.

Basis for effect:

growth rate

Remarks on result:

other: 95% CI: 0.17-0.17 mg a.i./L

Effect concentrations 4

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

0.092 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

act. ingr.

Basis for effect:

biomass

Remarks on result:

other: 95% CI: 0.089-0.093 mg a.i./L

Effect concentrations 5

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

0.093 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

act. ingr.

Basis for effect:

cell number

Remarks on result:

other: 95% CI: 0.090-0.096 mg a.i./L

Effect concentrations 6

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

0.1 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

act. ingr.

Basis for effect:

biomass

Remarks on result:

other: 95% CI: 0.099-0.10 mg a.i./L

Details on results:

- Exponential growth in the control (for algal test): yes
- Flocculation: no
- Adherence to test vessels: no
- Aggregation of algal cells: no

Any other information on results incl. tables

Concentration (mg a.i./L)  % Inhibition (Biomass 72 -hrs) % Inhibition (Biomass 96 -hrs)  % Inhibition (Growth Rate 72 -hrs)  % Inhibition (Growth Rate 96 -hrs)  % Inhibition (Yield 72 -hrs)   % Inhibition (Yield 96 -hrs)  0.019  -2  -3  0 -1  -1   -4  0.028  1  1  0  0  1  0  0.049  -2  -5  -1  -1  -4  -8  0.074  13  6  2  0  10  -1  0.12  89  75  38  14  88  57  0.18  99  98  81  56  99  97

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The 72-hr EC50 based on growth rate was 0.13 mg a.i./L.

Executive summary:

The acute toxicity of the test substance to algae was determined in an OECD Guideline 201 test. Algae were exposed to concentrations of 0, 0.019 mg a.i./L, 0.028 mg a.i./L, 0.049 mg a.i./L, 0.074 mg a.i./L, 0.12 mg a.i./L, and 0.18 mg a.i./L (measured) for 96 -hrs. The 72 -hr ErC50 was 0.13 mg a.i./L.