Ethyl octanoate

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2017-06-08 to 2017-10-13

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Version / remarks:

1992

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Version / remarks:

2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Remarks:

GC-MS

Details on sampling:

- Concentration: 9.00 mg/L
- Sampling method: the limit concentration and the control were analytically verified from all freshly prepared and aged media.
- Sample storage conditions before analysis: all samples were stored at 6 ± 2 °C until the start of the analysis, if necessary. Prepared samples were stored in the autosampler at room temperature until analysis.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: a stock solution of 20 mg/L was stirred for 24 hours at 1000 rpm. A volume of this was then transferred into a test vessel filled with dilution water. The test media was mixed with an ultraturrax (30 sec, 8500 rpm) and covered by a floating lid.
- Controls: 7
- Test concentration: approximate concentration of 5.57 mg/L

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: zebrafish
- Strain: Danio rerio
- Source: information available in full study report

ACCLIMATION AT TEST FACILITY
- Acclimation period: at least 12 days
- Acclimation conditions: same as test
- Type and amount of food during acclimation: Sera Vipan; Sera GmbH, 52518 Heinsberg, Germany. Amount: 4 % of the fish body weight per feeding day.
- Feeding frequency during acclimation: food was provided 3 times per week, but not fed 24h before the test start.
- Health during acclimation (any mortality observed): no mortality was observed during this time. No disease treatments were administered throughout holding and testing.

FEEDING DURING TEST
- Frequency: fish were not fed during the test.

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

67 mg CaCO3/L

Test temperature:

23.0-23.7°C

pH:

pH at the start of exposure: 6.93 (1.38 mg/L), 7.22 (control)
pH at the end of exposure: 7.53 (1.38 mg/L), 7.54 (control)

Dissolved oxygen:

Dissolved oxygen concentration: Not less than 60 % of air saturation except one value (44% on day 3 in the threshold concentration).
Dissolved oxygen at the start of exposure: 98% (1.38 mg/L), 99% (control)
Dissolved oxygen at the end of exposure: 84% (1.38 mg/L), 87% (control)

Conductivity:

138 μS/cm

Nominal and measured concentrations:

Nominal concentration of the test item: 9 mg/L
Geometric mean measured test item concentration: 1.38 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass aquaria of 13 L were used, filled with approximately 10 L of dilution water and covered with a floating lid
- Test volume: 10L per vessel
- Aeration: No aeration was provided from study start till 72 hours of exposure
- No. of organisms per vessel: 7 zebrafish
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: tap water of local origin
- Chlorine:filtered on activated charcoal and aerated for at least 24 h to remove chlorine.
- Alkalinity: 0.60 mmol/L

EFFECT PARAMETERS MEASURED
- Biological parameters: measurement of fish size; Observations were made after 4, 24, 48, 72 and 96h. An additional observation interval of 6h after each application was carried out.
- Physico-chemical properties: water quality and light intensity measurements; The pH-value, temperature and oxygen saturation were measured in all test vessels at test start and end and every 24 hours and after renewal of the test media from fresh and old test media.

OTHER TEST CONDITIONS
- Adjustment of pH: 6.5-7.0 by addition of 1 or 2 M HCl
- Photoperiod: A daily 16 hours photoperiod was maintained throughout exposure
- Light intensity: 7-750 Lux

Reference substance (positive control):

not required

Duration:

96 h

Dose descriptor:

LC0

Effect conc.:

1.38 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC100

Effect conc.:

> 1.38 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 1.38 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Biological data: no mortality occurred: all fish in this treatment survived until the end of the exposure.
- Physicochemical data: The environmental conditions (pH-value, temperature, oxygen-saturation) were determined to be within the acceptable limits. Light intensity was measured at the start of the exposure and ranged from 62 to 78 (mean value 68) Lux.

Sublethal observations / clinical signs:

Stability test (non-GLP):

Exposure time (h)	measured conc (mg/L)	% of nominal concentration
0	0.507	101
24	0.223	45

Observations in the Test Vessels:

Geometric mean measured Concentration [mg/L]	Observation *)	Number of fish affected after different exposure periods [hours]
		4	24	30	48	54	72	78	96
1.38	(E)	0	0	0	0	0	0	0	0
	(4.1)	0	4	4	6	6	7	7	7
	(2.6)	0	0	4	0	6	0	7	0
	(2.3)	2	4	0	6	0	7	0	0
	(1)	5	3	3	1	1	0	0	0
Control	(1)	7	7	-	7	-	7	-	7

*) The numbers in parentheses correspond to the following observation:

 (1)       =         Normal behavior

 (2.3)     =         Staggering

 (2.6)     =         Staggering has ceased, the effect was no longer evident

 (4.1)     =         Hyperventilation

 (E)       =         Exitus lethalis

 -        =         No observations

Cumulative Mortality [%] in the Test Vessels:

Geometric mean measured concentration [mg/L]	Cumulative Mortality [%] after different exposure periods [hours]
	4	24	48	72	96
1.38	0	0	0	0	0
Control	0	0	0	0	0

Analytical data:

Nominal concentration (mg/L)	Measured concentration (mg/L)								geometric mean
	0h, fresh	24h, aged	24h, fresh	48h, aged	48h, fresh	72h, aged	72h, fresh	95h, aged
9.00	8.46	2.85	8.51	< LOQ	8.11	< LOQ	8.54	2.25	1.38

Validity criteria fulfilled:

yes

Conclusions:

The test substance was found to cause non-lethal effects to zebrafish after 96 hours at a geometric mean measured test item concentration of 1.38 mg/L.

The LC50 (96h) is of > 1.38 mg/L (geometric mean measured concentration).

Executive summary:

The acute toxicity of the test item to fish (zebrafish) was determined according to the OECD Guideline for Testing of Chemicals No. 203 (1992) and EU Council Regulation No. 440/2008/C.1 (2008). A semi-static limit test was performed with a nominal threshold concentration of 9.00 mg/L. The test had a duration of 96 hours. 7 test organisms were exposed each for the test concentration and the control. The water quality parameters pH-value, temperature and oxygen saturation, measured after 0, 24, 48, 72 and 96 h, were determined to be within the acceptable limits.

The determination of the test concentration was carried out via GC-MS. Evaluation was carried out from all freshly prepared media after 0, 24, 48 and 72 h and from the corresponding 24 h aged test media after 24, 48, 72 and 96 h. The measured concentrations in freshly prepared media were in the range of 90 to 95 % of the nominal values. In corresponding 24 h aged test media, the measured concentrations were in the range of 25 to 32 % of the nominal values. Therefore, all effect values were based on the geometric mean measured concentration of the test item.

The nominal concentration 9.00 mg/L corresponds to a geometric mean measured concentration of 1.38 mg/L.

The LC50 (96h) is of > 1.38 mg/L (geometric mean measured concentration).

Description of key information

LC50 (96 h) > 1.38 mg/L (geometric mean measured concentration, Danio rerio, OECD 203).

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

1.38 mg/L

Additional information

For this study, 7 test organisms were exposed each for the test concentration and the control. The water quality parameters pH-value, temperature and oxygen saturation, measured after 0, 24, 48, 72 and 96 h, were determined to be within the acceptable limits.

The determination of the test concentration was carried out via GC-MS. Evaluation was carried out from all freshly prepared media after 0, 24, 48 and 72 h and from the corresponding 24 h aged test media after 24, 48, 72 and 96 h. The measured concentrations in freshly prepared media were in the range of 90 to 95 % of the nominal values. In corresponding 24 h aged test media, the measured concentrations were in the range of 25 to 32 % of the nominal values. Therefore, all effect values were based on the geometric mean measured concentration of the test item.

The nominal concentration 9.00 mg/L corresponds to a geometric mean measured concentration of 1.38 mg/L.