2-ethylhexanoic acid, monoester with propane-1,2-diol

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:

27 July 2020 to 31 July 2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Study undertaken to GLP certification, based on OECD guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

yes

Remarks:

the light intensity is lower than stated in the guideline (540 – 1000 lux). The range 400 – 800 lux is the light intensity in the husbandry. Because husbandry is successful since many years and the fish are in very good health, this deviation can be st

Principles of method if other than guideline:

Guideline study

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch number of test material:
RM1007030 RL750/18
- Expiration date of the lot/batch:
24/10/2020
- Purity: >99%

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material:
Closed vessel at room temperature (17.3 – 23.0 °C).
- Solubility and stability of the test substance in the solvent/dispersant/vehicle/test medium:
Solubility H2O: < 0.1 g/L; EtOH: > 1 g/L; acetone: > 1 g/L; CH3CN: > 1 g/L; DMSO: unknown; Stability: H2O: unknown; EtOH: 96h; acetone: 96h; CH3CN: 96h; DMSO: unknown

Analytical monitoring:

yes

Details on sampling:

- Concentrations:
Nominal concentrations were 4.6, 10, 22, 46, 100 mg/L
Time weighted mean concentrations were 3.8, 8.62, 19.46, 40.67, 92.93 mg/L

- Sampling method:
At the start of the test, at each medium renewal and at the end of the test, the content of the test item in the old and new test solutions was determined using LC-MS-MS. The concentration 10 mg/L was diluted twofold, the concentration 22 mg/L was diluted fourfold, the concentration 46 mg/L was diluted eightfold and the concentration 100 mg/L was diluted hundredfold before measurement.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
Test solutions containing 100 mg/L in tap water were prepared. For this, the loading rates of 106.4 µL/L (based on a density of 0.94 g/mL, stated in the SDS) were mixed with tap water and shaken on an orbital shaker for 30 minutes in order to achieve complete dissolution.
The lower treatments (46 / 22 / 10 / 4.6 mg/L) were prepared by dilution of this stock solution with tap water.

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: Zebrafish
- Source: Offspring form original University Heidelberg, 2019 source
- Age at study initiation (mean and range, SD): sexually immature young fish
- Length at study initiation (length definition, mean, range and SD): mean 1.9 cm, range 1.8 – 2 cm, SD 0.11 cm (measurements taken 4 days before test commencement)
- Weight at study initiation (mean and range, SD): mean 176.72 mg, range 129.7 - 261.9 mg, SD 44.24 mg (measurements taken 4 days before test commencement)
- Method of breeding: The test fish are kept following SOP 115 005 04 “Hälterung und Zucht von Zebrabärblingen (Danio rerio)”, edition 7, valid from 15. Jan. 2020.

ACCLIMATION
- Before the fish were set into the aquaria, temperature adaptation has taken place.

FEEDING DURING TEST
- 24 hours before the start of the test, the test fish were no longer fed.

Test type:

semi-static

Water media type:

freshwater

Remarks:

drinking water

Limit test:

no

Total exposure duration:

96 h

Remarks on exposure duration:

None

Post exposure observation period:

None

Hardness:

195.8 mg CaCO3/L on day 0

Test temperature:

22.6 - 24.6 C, recorded every 24 hours in old and new test solutions

pH:

7.3 - 8.4, recorded every 24 hours in old and new test solutions

Dissolved oxygen:

7.7 - 8.9 mg O2/L, recorded every 24 hours in old and new test solutions

Salinity:

Not applicable

Conductivity:

270 µS/cm, from tap water report

Nominal and measured concentrations:

Nominal concentrations were 4.6, 10, 22, 46, 100 mg/L
Time weighted mean concentrations were 3.8, 8.62, 19.46, 40.67, 92.93 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: glass aquaria, maximal volume 12 L
- Fill volume: 7 L
- Aeration: accomplished with glass tubes
- Renewal rate of test solution (frequency/flow rate): every 24 hours
- No. of organisms per vessel: 7
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates):1

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Drinking water
- Total organic carbon: <0.5 mg/L
- Particulate matter: No data
- Culture medium different from test medium: No
- Intervals of water quality measurement: Not stated, drinking water quality report

OTHER TEST CONDITIONS
- Adjustment of pH: None
- Photoperiod: 12/12
- Light intensity: Not stated

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

46.66 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Mortality of control: 0

Results with reference substance (positive control):

No data

Reported statistics and error estimates:

Analysis of mortality data was carried out using a probit model.Calculation of results was performed with the help of validated software. The estimation of the biological results was accomplished using the software ToxRat® Professional, version 3.3.0.

Validity criteria fulfilled:

yes

Conclusions:

The toxicity to Danio rerio was tested using a semi-static test design in a GLP study to the OECD 203 Guideline. Every 24 hours a medium renewal was performed and the surviving fish were transferred into freshly prepared solutions. The highest concentration 100 mg/l (nominal concentration) showed 100 % mortality. In the next highest concentration (46 mg/L) 1 fish died. No fish mortalities were observed in the control and the lower concentrations (4.6 – 22 mg/L). All validity criteria were met. An LC50 of 46.66 mg/l was derived as a measured time-weighted average concentration in the 96 hour acute toxicity study.

Executive summary:

The toxicity to Danio rerio was tested using a semi-static test design. Every 24 hours a medium renewal was performed and the surviving fish were transferred in fresh prepared solutions. The study was performed using five concentrations ranging from 4.6 to 100 mg/L (nominal). The highest concentration tested 100 mg/L showed 100 % mortality. In the next highest concentration (46 mg/L) 1 fish died. No fish died in the control and the lower concentrations of 4.6 – 22 mg/L. At the start of the test, at each medium renewal and at the end of the test, the content of the test item in the old and new test solutions was determined using HPLC. The measured concentrations were in a range between 76 % and 97 % of the nominal concentrations. Therefore, the time-weighted arithmetic mean was used for determination of the biological results (see OECD guidance document No. 23, Annex 2). The following results for the test substance were determined:

 

96h-LC₅₀ = 46.66 mg/L

Description of key information

The 96-h LC50 was 46.66 mg/l based on D. rerio mortality (Muckle 2020)

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

46.66 mg/L