Octadecanoic acid, C16-18-alkyl esters

Long-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

05 Jan - 22 May 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.20 (Daphnia magna Reproduction Test)

GLP compliance:

yes (incl. QA statement)

Remarks:

Swiss Federal Office of Public Health, Bern, Switzerland

Test material

Test material information

Constituent 1

Reference substance name:

(Z)-octadec-9-enyl oleate

EC Number:

222-980-0

EC Name:

(Z)-octadec-9-enyl oleate

Cas Number:

3687-45-4

IUPAC Name:

octadec-9-en-1-yl octadec-9-enoate

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: Control, 100 mg/L
- Sampling method: Duplicate samples were taken from the freshly prepared test medium of the single test concentration and from the control at one treatment period of the first, second and last week of the test (day 0, 2, 7 and 16, respectively). To determine the maintenance of the test substance concentration in test medium, stability samples were taken at the end of two test medium renewal periods of 48 h (day 2 and 9) and at the end of two renewal periods of 72 h (days 5 and 19).
- Sample storage conditions before analysis: All samples were stored deep-frozen (at about -20 °C) and protected from light immediately after sampling.

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: A dispersion with the nominal concentration of 100 mg/L was prepared prior to the start of the test and prior to each medium renewal by dispersing 400 and 200 mg of the test item (dosed in the range of 400 to 401 mg on days 0, 7 and 16 and in the range of 200 to 201 mg on days 2, 5, 9, 12, 14 and 19) in 4000 and 2000 mL of test water under intense stirring for 96 h at room temperature in the dark to avoid photolytic degradation. After the 96 h stirring period, the test item was filtered through a membrane filter (Schleicher & Schuell, Type NC45, pore size 0.45 µm). The test medium was prepared just before the start of the test (= addition of daphnids) and before each test medium renewal.
- Eluate: no
- Differential loading: no
- Controls: yes, test medium control

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Source: Originally supplied by the University of Sheffield/UK in 1992. Since this date, the clone is successfully bred at Harlan Laboratories.
- Age of parental stock (mean and range, SD): < 24 h
- Feeding during test
- Food type: food mixture containing a suspension of green algae of the species Scenedesmus subspicatus (freshly grown at the laboratory) and a fish food suspension. The fish food suspension was prepared by dispersing 10 g of powdered commercial fish diet (TETRA MIN Hauptfutter, obtained from TETRA-Werke, Melle, Germany) in 500 mL of test water. The suspension was allowed to stand for 4 hours. Then, 400 mL of the supernatant were taken, diluted 1:1 with test water and boiled. The suspension was stored deep frozen in small quantities until use.
- Amount: 0.20 mg TOC per Daphnia and day
- Frequency: daily
- Method of breeding: Each stock animal was maintained separately in a 100 mL glass beaker filled with about 80 mL culture medium and was transferred twice a week to fresh medium. The condition of the stock animals was frequently checked. No signs of stress were observed and the brood stock was healthy.

ACCLIMATION
- Acclimation period: The daphnids used for the test originated form parental daphnids that were at least 14 d old but not older than four weeks and were not first brood progeny.
- Acclimation conditions (same as test or not): same as test
- Type and amount of food: same as test
- Feeding frequency: three times a week

Study design

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

21 d

Test conditions

Test temperature:

20 - 21 °C

pH:

7.7 - 8.1

Dissolved oxygen:

8.2 - 9.2 mg O2/L

Nominal and measured concentrations:

nominal: control, 100 mg/L
measured: < LOQ in the control and treatment

Details on test conditions:

TEST SYSTEM
- Test vessel: beakers
- Type (delete if not applicable): covered with glass plates to reduce loss of water by evaporation and to avoid the entry of dust into the solutions.
- Material, size, headspace, fill volume: glass, 100 mL, headspace: 20 mL, fill volume: 80 mL
- Aeration: no
- Renewal rate of test solution (frequency/flow rate): renewed on days 2, 5, 7, 9, 12, 14, 16 and 19.
- No. of organisms per vessel: 1
- No. of vessels per concentration (replicates): 20
- No. of vessels per control (replicates): 20

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: reconstituted water (Elendt M7 medium)
- Alkalinity: 0.9 mmol/L
- Water hardness: 250 mg/L as CaCO3
- Culture medium different from test medium: no

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 h light / 8 h dark (30 min transition period)
- Light intensity: 400 - 540 lux

EFFECT PARAMETERS MEASURED: Mortality and reproduction on days 0-2 and thereafter at least three times per week before renewal of test media. On the same dates, the test repliacates were observed for the number of living and dead offspring and for the presence of aborted eggs.

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

21 d

Dose descriptor:

NOELR

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

reproduction

Effect concentrations 2

Duration:

21 d

Dose descriptor:

EL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

mortality

Details on results:

- Mortality of parent animals: 0% in control; 5% in treatment
- Type and number of behavioural abnormalities: No visible abnormalities were observed during the test.
- No. of offspring produced after 21 d per female: 142 (mean, control); 137 (mean, treatment)
- Time to first brood release or time to hatch: day 9 in control and treatment

Reported statistics and error estimates:

Student t-test (one-sided smaller, α = 0.05) with the mean values of living offspring.