Decanoic acid, ester with 2,2-bis(hydroxymethyl)-1,3-propanediol 2-ethylhexanoate 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:

10 September 2017 - 03 November 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

not specified

Details on sampling:

- Concentrations:
- Sampling method:
- Sample storage conditions before analysis:

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method:Due to the low aqueous solubility and complex nature of the test item, for the purposes of the study the test medium was prepared as a Water Accommodated Fraction (WAF) of the test item.
- Eluate:
- Differential loading:
- Controls:
- Chemical name of vehicle (organic solvent, emulsifier or dispersant):
- Concentration of vehicle in test medium (stock solution and final test solution(s) or suspension(s) including control(s)):
- Evidence of undissolved material (e.g. precipitate, surface film, etc.):

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name:rainbow trout
- Strain:Oncorhynchus mykiss
- Source:Brow Well Fisheries Limited, Hebden, near Skipton, Yorkshire, UK
- Length at study initiation (length definition, mean, range and SD):fish had a mean standard length of 4.5 cm (sd = 0.14)
- Weight at study initiation (mean and range, SD):mean weight of 0.62 g (sd = 0.09) at the end of the definitive test.
- Maintenance of the brood fish:Fish were maintained in a glass fiber tank with a "single pass" water renewal system.

ACCLIMATION
- Acclimation period:Fish were acclimatized to test conditions from 19 September 2017 to 26 Septewmber 2017.
- Acclimation conditions (same as test or not): Same as test.
- Type and amount of food during acclimation:The stock fish were fed commercial trout pellets which was discontinued approximately 20 hours prior to the start of the definitive test.
- Health during acclimation (any mortality observed): No Mortality observed.

Test type:

semi-static

Water media type:

freshwater

Total exposure duration:

96 h

Hardness:

140 mg/L as CaCO3.

Test temperature:

The test vessels were then covered to reduce evaporation and maintained at 15 °C to 16 °C in a temperature controlled room.

pH:

7-8

Dissolved oxygen:

9.6-10 mg o2/L

Details on test conditions:

Definitive Test
In accordance with the recommendations of REACh, the test was conducted according to the threshold approach recommended by ECHA. Using this approach the lowest EL50 value from either the Algal Growth Inhibition study or Acute Toxicity to Daphnia magna study is set as the threshold loading rate and a “Limit test” is conducted at this threshold loading rate. If no mortalities are observed this indicates that fish are not the most sensitive species and that the LL50 is greater than the threshold loading rate. Therefore, as the EL50 value obtained for both the Algal Growth Inhibition study and the Acute Toxicity to Daphnia magna study (Envigo Study Numbers HT64VT and SQ03JR respectively) were greater than 100 mg/L loading rate WAF, the test was conducted at a single loading rate of 100 mg/L loading rate WAF to ensure that toxicity was not observed at this loading rate.


Experimental Preparation
A nominal amount of test item (2200 mg) was added to the surface of 22 liters of test water to give the 100 mg/L loading rate. After the addition of the test item, the test water was stirred by magnetic stirrer using a stirring rate such that a vortex was formed to give a dimple at the water surface. The stirring was stopped after 23 hours and the mixture allowed to stand for 1 hour. A wide bore glass tube, covered at one end with Nescofilm was submerged into the vessel, sealed end down, to a depth of approximately 5 cm from the bottom of the vessel. A length of Tygon tubing was inserted into the glass tube and pushed through the Nescofilm seal. Microscopic inspection of the WAF showed no micro-dispersions or undissolved test item to be present. The aqueous phase or WAF was removed by mid-depth siphoning (the first 75-100 mL discarded) to give the 100 mg/L loading rate WAF. The concentration and stability of the test item in the test preparations were verified by chemical analysis at 0, 24, 72 and 96 hours.

Exposure Conditions
In the definitive test, 25-30 liter glass exposure vessels containing 20 liters of test media were used for each control and test concentration. At the start of the test seven fish were placed in each test vessel at random, in the test preparations. The test vessels were then covered to reduce evaporation and maintained at 15 °C to 16 °C in a temperature controlled room with a photoperiod of 16 hours light and 8 hours darkness with 20 minute dawn and dusk transition periods for a period of 96 hours. The test vessels were aerated via narrow bore glass tubes. The fish were not individually identified and received no food during exposure.
The control group was maintained under identical conditions but not exposed to the test item.
A semi-static test regime was employed in the test involving a daily renewal of the test preparations to prevent the build-up of nitrogenous waste products.

Reference substance (positive control):

not specified

Key result

Duration:

96 h

Dose descriptor:

LL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (dissolved fraction)

Key result

Duration:

96 h

Dose descriptor:

NOELR

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (dissolved fraction)

Details on results:

Validation of Mixing Period
Preliminary investigational work (see Annex 3) indicated that there was no significant increase in the amount of dissolved test item when the preparation period was extended for longer than 24 hours. Therefore, for the purpose of testing the WAF was prepared using a stirring period of 23 hours followed by a 1-Hour settlement period.

Chemical Analysis of Test Loading Rates
The dissolved test item may have been one or several components of the test item. Given that toxicity cannot be attributed to a single component or mixture of components but to the test item as a whole, the results were based on nominal loading rates only.


The No Observed Effect Loading rate (NOEL) was considered to be 100 mg/L loading rate WAF. It was considered unnecessary and unrealistic to test at loading rates in excess of 100 mg/L.

Sub-Lethal Effects
There were no sub-lethal effects of exposure observed in 7 fish exposed to a 100 mg/L loading rate WAF for a period of 96 hours.

Observations on Test Item Solubility
Observations on the test media were carried out during the mixing and testing of the WAF.
At the start of the mixing period the 100 mg/L loading rate was observed to be a clear colorless water column with oily globules of test item on the surface. After 23 hours stirring and a 1-Hour standing period the 100 mg/L loading rate was observed to be a clear colorless water column with an oily layer of test item on the surface. Microscopic inspection of the WAF showed no micro-dispersions or undissolved test item to be present. After siphoning and for the duration of the test, the control and 100 mg/L loading rate was observed to be clear, colorless solutions.

Validity criteria fulfilled:

yes

Conclusions:

The acute toxicity of the test item to the freshwater fish rainbow trout (Oncorhynchus mykiss) has been investigated using the threshold approach and gave a 96-Hour LL50 value of greater than 100 mg/L loading rate WAF. The No Observed Effect Loading rate was 100 mg/L loading rate WAF.

Executive summary:

Introduction

A study was performed to assess the acute toxicity of the test item to rainbow trout (Oncorhynchus mykiss). The method followed was designed to be compatible with the OECD Guidelines for Testing of Chemicals (1992) No 203, "Fish, Acute Toxicity Test" referenced as Method C.1 of Commission Regulation (EC) No. 440/2008.

  Methods…….

Due to the low aqueous solubility and complex nature of the test item, for the purposes of the test, the test medium was prepared as a Water Accommodated Fraction (WAF).

In accordance with the recommendations of REACh, the test was conducted according to the threshold approach recommended by ECHA.  Using this approach the lowest EL₅₀value from either the Algal Growth Inhibition study or Acute Toxicity toDaphnia magnastudy is set as the threshold loading rate and a “Limit test” is conducted at this threshold loading rate.  If no mortalities are observed this indicates that fish are not the most sensitive species and that the LL₅₀is greater than the threshold loading rate. Therefore, as the EL₅₀value obtained for both the Algal Growth Inhibition study and the Acute Toxicity toDaphnia magnastudy (Envigo Study Numbers HT64VT and SQ03JR respectively) were greater than 100 mg/L loading rate WAF, the test was conducted at a single loading rate of 100 mg/L loading rate WAF to ensure that toxicity was not observed at this loading rate.

Seven fish were exposed to a Water Accommodated Fraction (WAF) of the test item, at a single nominal loading rate of 100 mg/L for a period of 96 hours at a temperature of 14°C to 15 ºC under semi-static test conditions. The number of mortalities and any sub-lethal effects of exposure in each test and control vessel were determined 3 and 6 hours after the start of exposure and then daily throughout the test until termination after 96 hours.

 Results

Given that the toxicity cannot be attributed to a single component or a mixture of components, but to the test item as a whole, the results were based on nominal loading rates only.

Exposure of rainbow trout to the test item gave LL₅₀values of greater than 100 mg/L loading rate WAF. The No Observed Effect Loading Rate was 100 mg/L loading rate WAF.

It was considered unnecessary and unrealistic to test at loading rates in excess of 100 mg/L loading rate WAF.

Description of key information

The acute toxicity of the test item to the freshwater fish rainbow trout (Oncorhynchus mykiss) has been investigated using the threshold approach and gave a 96-Hour LL50 value of greater than 100 mg/L loading rate WAF.  The No Observed Effect Loading rate was 100 mg/L loading rate WAF.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

100 mg/L