Hexanoic acid, 2-ethyl-, C16-18-alkyl esters

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

12 - 13 Jun 2012

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study with acceptable restrictions: The study is not performed under GLP conditions. No test substance monitoring is performed.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

no

Remarks:

but performed according to ISO 17025

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Test solutions are prepared in accordance with the OECD monography n°23. Aqueous daphnia test medium is saturated with the substance to be tested by dynamic contact setting with a known test substance amount. The preparation consists of 68 h of gentle agitation by magnetic stirring to obtain a vortex of about 1/3 (or less under some conditions) of the height between the top and the bottom of the flask, followed by 4 h of phase separation.The aqueous phase, containing the soluble substances is taken to perform the test. The test solution is identified to its loading rate (massic proportion of substance to be tested/ test medium mass introduced into the diphasic reactor) while operating the Water accomodated fraction (WAF). The implemented loaded ratio is : 0.10/1000.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Source: in-house culture (obtained by acyclic parthenogenese; minimum second generation)
- Age at study initiation: < 24 h
- Method of breeding: Daphnia are hold in dilution water according to OECD guideline 202.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test temperature:

21 ± 1 °C

pH:

7.8 ± 0.2 (7.7 at end of test in control and treatment)

Dissolved oxygen:

> 7 mg/L

Nominal and measured concentrations:

Nominal: 100 mg/L loading rate WAF

Details on test conditions:

TEST SYSTEM
- Test vessel: test tube
- Size: 100 mL; Fill volume: 100 mL
- No. of organisms per vessel: 10
- No. of vessels per concentration: 2
- No. of vessels per control: 2

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: according to OECD guideline 202
- Culture medium different from test medium: no
- Intervals of water quality measurement: not specified

OTHER TEST CONDITIONS
- Photoperiod: The test is performed in darkness.

EFFECT PARAMETERS MEASURED: Immobilisation was recorded after 24 and 48 h test duration.

Reference substance (positive control):

no

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

(WAF)

Basis for effect:

mobility

Details on results:

No mortality was observed in the control and the treatment during the test period of 48 h. The daphnia did not show any abnormal behaviour during the test and no external apparent impact was detected.

Description of key information

No toxic effects up to the limit of water solubility (< 0.15 mg/L) for Daphnia magna (OECD 202)

Additional information

One study investigating the short-term toxicity of Hexanoic acid, 2-ethyl-, C16-18 alkyl esters (CAS No. 90411-68-0) to aquatic invertebrates is available. The non-GLP study was conducted under static conditions according to OECD guideline 202 using Daphnia magna as test organism (Bouillon, 2012). A 100 mg/L loading rate WAF was tested in a limit test. No mortality was observed in the treatment and the control throughout the test period of 48 h. Hence, a 48 h-EL50 is determined to be > 100 mg/L based on the nominal test concentration.

A detailed reference list is provided in the technical dossier (see IUCLID, section 13) and within the CSR.