Sodium 2-(1-carboxylatoethoxy)-1-methyl-2-oxoethyl isooctadecanoate

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:

2018-03-07 to 2018-05-08

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:

17 July 1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: 1731200025
- Expiration date of the lot/batch: November 10, 2018

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Store in original container; keep original container closed and store in a well-ventilated area at 13–29 °C
- Stability under test conditions: Not stable, slow hydrolysis is observed

Analytical monitoring:

yes

Details on sampling:

Fresh samples were taken from the test solution and control at the beginning of the exposure period and at each medium renewal prior to distribution to test vessels. At each medium renewal and at the end of the test, aged samples were taken per test concentration and control. Samples were added to methanol immediately after sampling for stabilization of the sample. The samples and retain samples were frozen at -20 °C until analysis.

Vehicle:

no

Details on test solutions:

Due to the very low water solubility of the test item, the highest test concentration was prepared with a loading of 100 mg test item/L with stirring of the stock solution for approximately 1 hour.
A teflon weighing boat with the required test item amount was transferred into a glass flask. Cu-reduced dilution water was added to the bottle and stirred vigorously for about 1 hour at room temperature (about 20 °C) to achieve maximum solubility of the test item.
To separate insoluble test item from the test solution, it was filtered using 0.22 µm PES filter (polyethersulfone, bottle top filter). The filtrate was used as highest test concentration and was subsequently diluted with Cu reduced dilution water to obtain the other test concentrations.
The test solutions were freshly prepared before test start and prior to each media renewal.

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

Species: Zebrafish (Danio rerio, Teleostei, Cyprinidae)
Source: Test facility bred
Size: 2.0 cm ± 1.0 cm
Holding: The fish were constantly held in water of the same quality as used in the test (purified drinking water)
Health: The criteria of the test guideline [4] were followed. Only healthy fish without diseases and abnormalities were used in the study. Mortality of the batch was less than 5 % in the week preceding the start of the study.

Holding conditions:
The fish were held for at least 12 days prior to the test under generally equivalent water quality and illumination conditions to those proposed for use in the test. Fish were fed ad libitum throughout the holding period with live brine shrimp (Artemia spp.) nauplii and ground flake food TetraMin® (Tetra Werke, Melle, Germany) once a day.

FEEDING DURING TEST
No feeding occurred during the test as well as 24 h before test start.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Remarks on exposure duration:

Media renewal after 24, 48 and 72 hours (fresh and aged media) and after 96 hours (aged media)

Hardness:

Total hardness 1.0 mmol/L

Test temperature:

23.0 ± 2.0 °C

pH:

8.14–8.35

Dissolved oxygen:

90–100 %

Conductivity:

254 µS/cm

Nominal and measured concentrations:

Nominal concentrations: 6.25, 12.5, 25.0, 50.0 and 100.0 mg/L
Measured concentrations: 0.025, 0.031, 0.094, 0.199 and 0.439 mg/L

Details on test conditions:

Mortality and abnormal behaviour was recorded after 24 h, 48 h, 72 h and 96 h. Abnormal behaviour includes e.g. loss of equilibrium, swimming behaviour, respiratory function, and altered pigmentation. The fish loading met the criteria of the OECD guideline.
Seven fish were used for each test concentration and for the control, respectively. The light/dark cycle was adjusted to 12/12 hours. The test solutions were slightly aerated via glass capillaries. The control group was held under the same conditions as the fish in the test concentrations. No feeding occurred during the test as well as 24 h before test start.
Before beginning of the study, a subsample of seven randomly chosen fish from the fish batch used in the test was measured for length and weight. Oxygen concentration, pH-value and temperature was measured directly before adding the fish and afterwards once per day. The test solution was replaced daily. Samples of control and test solutions were taken at test start, each medium renewal of aged and renewed test solution, and at test end after 96 h.
The test vessels were full glass beakers of 3 L, containing 2 L of test solution. One test vessel each for control and test item was installed. The maximum allowed loading of fish of 1 g/L defined in the test guideline was regarded.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2
- Range finding study: yes
- Test concentrations: 1.0, 10.0 and 100 mg test item/L
- Results used to determine the conditions for the definitive study: yes

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 0.439 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

No effects on behaviour or survival of fish were detected during the test course up to and including the highest test concentration of 0.439 mg/L.

Reported statistics and error estimates:

Not applicable

Sublethal observations / clinical signs:

Neither biological effects nor mortality occurred during the test.

Validity criteria according the OECD guideline 203 were met:  

• Mortality did not exceed 10 % in the controls.  

• The dissolved oxygen concentration was ≥ 60 % in test vessels throughout the test.

Validity criteria fulfilled:

yes

Conclusions:

The LC50 was determined to be > 0.439 mg/L sodium isostearoyl lactylate (geometric mean measured).

Executive summary:

In a 96-h acute toxicity study, zebra fish (Danio rerio) were exposed to Sodium-Isostearoyl-Lactylate at nominal concentrations of 0.0 (control) and 6.25, 12.5, 25.0, 50.0 and 100.0 mg/L under semi-static conditions. The LC₅₀ value, based on mortality, was > 0.439 mg/L (geometric mean measured concentration). Sublethal effects were not observed.

Based on the results of this study, the test item would be not classified as toxic to zebra fish in accordance with the CLP classification system.

This toxicity study is classified as acceptable and satisfies the guideline requirement for the zebra fish acute toxicity study.

Results synopsis

Test organism size/age: Danio rerio (size 2.0 cm ± 1.0 cm)

Test type: Semi-static

LC₅₀ > 0.439 mg/L

Endpoint(s) effected: Mortality, other effects (i.e. swimming behaviour, colour, respiratory function or any other observable morphological or visual behavioural criterion)

Description of key information

In a valid 96-h acute toxicity study, zebra fish (Danio rerio) were exposed to sodium isostearoyl lactylate at nominal concentrations of 0.0 (control) and 6.25, 12.5, 25.0, 50.0 and 100.0 mg test item/L under semi-static conditions. The LC₅₀ value, based on mortality and sublethal effects, was > 0.439 mg/L (geometric mean measured concentration). This was the maximum attainable test substance concentration. Sublethal effects were not observed.

The absence of any mortality indicates that, according to the threshold approach for acute fish toxicity, fish is not the most sensitive group of test organisms after short-term exposure to sodium isostearoyl lactylate. Accordingly, for hazard assessment, the LC50 is artificially set at 1 mg/L, to reflect the lower sensitivity of fish in comparison to invertebrates.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

1 mg/L