Propane-1,2,3-triyl 3,5,5-trimethylhexanoate

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:

28 January-01 March 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

GLP compliance:

yes (incl. QA statement)

Remarks:

The Department of Health of the Government of the United Kingdom

Analytical monitoring:

yes

Details on sampling:

- Sampling method: Water samples were taken from the solvent control and the 100% v/v solution test vessel at 0 and 72 h (fresh media) and at 24 and 96 hours (old media). Duplicate samples and samples at 24 (fresh media), 48 (old and fresh media) and 72 hours (old media) were taken and stored for further analysis if necessary.
- Sample storage conditions before analysis: The samples were stored at approximately -20 °C prior to analysis.

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: An amount of test item (100 mg) was dissolved in dimethylformamide and the volume adjusted to 10 mL to give a 100 mg/10 mL solvent stock solution. An aliquot (2.2 mL) of this solvent stock solution was dispersed in 22 liters of dechlorinated tap water with the aid of magnetic stirring for approximately 10 minutes. After stirring, any undissolved test item was removed by filtration through a 0.2 µm filter to give the required concentration of 100% v/v. The test media was stirred using a flat-bladed mixer for approximately 1 minute to ensure homogeneity
- Controls: blank and solvent control
- Chemical name of vehicle: dimethylformamide
- Concentration of vehicle in test medium: the solvent control group was exposed to 100 µL/L of dimethylformamide
- Evidence of undissolved material: clear colourless solutions were reported

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: Rainbow trout
- Source: Brow Well Fisheries Ltd., Yorkshire, United Kingdom
- Length at study initiation: mean= 4.4 cm; standard deviation= 0.5 cm
- Weight at study initiation: mean= 1.14 g; standard deviation= 0.31 g
- Feeding during test: not fed

ACCLIMATION
- Acclimation period: Fish were acclimatized to test conditions from 23 January 2013 to 4 February 2013
- Acclimation conditions (same as test or not): yes
- Type and amount of food: commercial trout pellets
- Health during acclimation (any mortality observed): there was no mortality in the 7 days prior to the start of the test

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

140 mg CaCO3/L

Test temperature:

13-14 °C

pH:

7.8-8.2

Dissolved oxygen:

9.5-11.5 mg O2/L (92-112% air saturation value)

Salinity:

Not applicable

Nominal and measured concentrations:

Nominal: control, solvent control, 100% v/v
Measured: control, solvent control, < 0.0060 mg/L (LOQ)

Details on test conditions:

TEST SYSTEM
- Test vessel: 20 L glass vessels
- Aeration: yes, via narrow bore glass tubes
- Renewal rate of test solution: daily
- No. of organisms per vessel: 7
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- No. of vessels per vehicle control (replicates): 1

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Laboratory tap water was dechlorinated by passage through an activated carbon filter and partly softened. After dechlorination, the water was passed through a series of computer controlled plate heat exchangers to achieve the required temperature

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: 16 hours light and 8 hours darkness with 20 minute dawn and dusk transition periods

EFFECT PARAMETERS MEASURED: Mortality and sub-lethal effects at t=0, 24, 48, 72 and 96 hours

TEST CONCENTRATIONS
- Range finding study
- Test concentrations: 100% v/v
- Results used to determine the conditions for the definitive study: No mortalities observed at the tested concentration

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 other: v/v

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- No mortality or any other sub-lethal effects were observed in control or treatment groups.
- The tested concentration of 100% v/v solution was the highest attainable test concentration that could be prepared due to the limited solubility of the test item in water and having due regard to the amount of auxiliary solvent permitted according to the OECD Guidelines. Other various recognized auxiliary solvents were used during preliminary solubility work, however, dimethylformamide was found to give the best testable dispersion of the test item in water. At higher test concentrations, there was a marked precipitation of the test item on addition of the solvent stock solution to water.

Description of key information

LC50 (96 h) > 100% v/v (nominal) for Oncorhynchus mykiss (OECD 203)

Additional information

One study evaluating the acute toxicity of propane-1,2,3 triyl 3,5,5-trimethylhexanoate (CAS No. 56554-53-1) to fish species is available (Parr, 2013). This test was conducted according to OECD 203, under GLP conditions. Oncorhynchus mykiss was exposed to the test substance for 96 hours within a semi-static water regime, at a nominal concentration of 100% v/v (limit test, based on the result of a range-finding study). A preliminary media preparation test was performed due to the poorly soluble nature of the substance (water solubility < 0.05 mg/L). The results from this pre-test showed that a solvent spike method was the most appropriate method for media preparation. The test solution was then prepared using a solvent spike method (with dimethylformamide) at an initial concentration of 1 mg/L, stirred for approximately 10 minutes prior to removal of any undissolved test substance by filtration, leading to the 100% v/v. The analytically determined (GC) concentration of test item in the solution was under the limit of quantification (LOQ) of the method (0.0060 mg/L) and therefore the results are expressed based on nominal values.

After 96 hours of exposure to the test substance, no mortality or sub-lethal effects were observed at the tested concentration. Therefore, the LC50 (96 h) was determined to be > 100 v/v, considered to be the highest attainable concentration in test solution.