Potassium 2-ethylhexanoate

Long-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Scientifically acceptable. Missing data about the purity of the test substance. An analytical sheet in finnish language is added to the report as appendix 4.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1997

Report date:

1997

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

2-ethylhexanoic acid

EC Number:

205-743-6

EC Name:

2-ethylhexanoic acid

Cas Number:

149-57-5

IUPAC Name:

2-ethylhexanoic acid

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

no

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

Test organism: Daphnia magna
Origin : Natural pond, laboratory cultured since 1986
Culture conditions, Dilution water according to ISO 6341 standard
Temperature 23 +/-1°C, Ilght/dark-cycle 17/7 h, light intensity 1200 lux
Feeding : Green algae Selenastrum capricornutum (Nlva chi 280384 )
cultured in nutrient solution according to standard ISO 8692

Study design

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Test conditions

Test temperature:

21.5 - 23.4°C

pH:

7.7 - 8.1

Dissolved oxygen:

79 - 100%

Details on test conditions:

Method: Semistatic test, renewal of test solutions 3 times/week, 10 replicates/concentration, 1 parent animal/replicate, 40 ml test solution/parent animal
Test concentrations : 0, 1 . 6 , 4 , 10, 25, 63 mg/I
Selection of concentratlons: Test concentrations were chosen according to the 24 h-EC50 -value
(139 mg/l) for acute toxicity so that parental Daphnias wouldn't die
during the 21 d exposure
Light intensity/cycle : 1200 - 1500 lux. Iight/dark-cycle 17/7 h
Dilution water. Inorganic salt solution supplemented with vitamins =
dilution water Elendt M7 (OECD 211) + dilution water (ISO 6341), proportions 1 : 1
Dilution waters were prepared in activated carbon and reverse osmosis filtered tap water, conductivity 0.5 mS/m
Dilution waters were aerated for 24 h before use, pH was settled at range 7 .7-7 . 8
Stock solution: 2-ethylhexanoic acld 1000 mg/I Elendt M7 dilution water (pH 3 .9 )
Renewal of the test solutions: Renewal frequency monday-wendsday-friday
Fresh solutions were prepared from the stock solution and dilution waters into replicate test vessels just before each renewal
Newbom offspring (living-dead-eggs) were counted from the old test solutions
Parent animals were carefully transferred to the fresh solutions by pipetting
Concentrated algal feed was added into the fresh test solutions according to the TOC concentration determined from cell density

Reference substance (positive control):

not specified

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

25 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

reproduction

Effect concentrations 2

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

75 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

reproduction

Effect concentrations 3

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

63 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

reproduction