12-oxahexadecan-16-olide

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

10 April to 21 September 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

12-oxahexadecan-16-olide

EC Number:

229-755-6

EC Name:

12-oxahexadecan-16-olide

Cas Number:

6707-60-4

Molecular formula:

C15H28O3

IUPAC Name:

1,6-dioxacycloheptadecan-7-one

Test material form:

liquid

Specific details on test material used for the study:

Test material name (as stated in the report): Cervolide
Batch No.:VE00445215
Purity : 99.8%
Expiry date: June 07, 2018

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

At the start of the exposure intervals (0 and 24 hours), sampling was carried out after preparation of the test concentrations.
At the end of the exposure intervals (24 and 48 hours), samples were taken directly from the test vessels.

Test solutions

Vehicle:

no

Details on test solutions:

Since the test item was determined to be volatile, the test was performed in glass vessels completely filled (without headspace) with 60 mL test medium and tightly sealed with glass stoppers to avoid losses of the volatile substance by evaporation (closed system).As the test item is a liquid with low water solubility (<100 mg/L), the slow-stirring method was applied for preparation of an equilibrated test item solution.the equilibrated test medium with a loading rate of 100 mg/L and the dilutions 1:2, 1:4, 1:8 and 1:16. Additionally, a control (test water without test item) was tested in parallel.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

Test system: Daphnia magna STRAUS clone
Origin: Daphnia Collection of the University of Basel/Switzerland in 2015
he organisms used in the test were 6-24 hours old and were not first brood progeny.
The daphnids were not fed during the test.

Study design

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test conditions

Hardness:

250 mg CaCO3/L

Test temperature:

20-21°C

pH:

7.7-7.9

Dissolved oxygen:

8.3-8.6mg/L

Nominal and measured concentrations:

5 test item concentrations in a geometric series with a separation factor of 2, prepared by diluting the stock solution of 100 mg/L loading rate with dilution water, were tested as follows:
6.25 - 12.5 - 25 - 50 - 100 mg/L.
The nominal concentrations mentioned above correspond to the geometric mean measured concentrations of:
0.78 - 1.4 - 3.4 - 6.8 - 16 mg/L.

Details on test conditions:

The study was conducted in a closed system (sealed glass flasks) without headspace under semistatic conditions over a period of 48 hours with 5 concentrations in the range of 6.25 to 100 mg/L of the test item CERVOLIDE in a geometric series with a separation factor of 2.
The test item CERVOLIDE is a colorless to pale yellow liquid with a water solubility of 24.6 mg/L (20 °C, pH 7). The test item was expected to be volatile. To reduce losses of the test item, the study was conducted in a closed system without headspace.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

10.3 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% CI = 6.7 - 16 mg/L

Effect concentrations 2

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

3.4 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 3

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

16 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

A clear dose-response effect was observed during the exposure period of 48 hours: At the three lowest test concentrations no toxic effect was observed. At the two highest test concentrations of 6.8 and 16 mg/L (mean measured), 5 and 100 % of the daphnids were found to be immobile
after 48 hours, respectively.
24-hour EC 50 is 12 mg/L, 48-hour EC 50 is 10.3 mg/L

Results with reference substance (positive control):

potassium dichromate is tested as a positive control twice a year. The result of the latest positive control test in March 2017 (24-hour EC50: 1.2 mg/L, IES Laboratories Study 20170076) showed that the sensitivity of the test organisms was within the range given by the guideline (24-hour EC50:
0.60-2.1 mg/L).

Any other information on results incl. tables

The water quality parameters (i.e. pH-value and dissolved oxygen concentration), measured at the start (0 and 24 hours) and at the end of the exposure intervals (24 and 48 hours), were within the acceptable limits. The validity criteria of the test guideline were fulfilled.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Acccording to the test conditions the EC50(48hours) of the test item CERVOLIDE with 95 % confidence limits has been determined to be 10.3 mg/L (Cl: 6.7-16) based on geometric mean measured test item concentrations.

Executive summary:

In the acute immobilisation test with Daphnia magna (STRAUS), the effects of the test item CERVOLIDE were determined according to OECD 202 guideline.

5 test item concentrations in a geometric series with a separation factor of 2, prepared by diluting the stock solution of 100 mg/L loading rate with dilution water, were tested as follows:

6.25 - 12.5 - 25 - 50 - 100 mg/L.

The nominal concentrations mentioned above correspond to the geometric mean measured concentrations of:

0.78 - 1.4 - 3.4 - 6.8 - 16 mg/L.

The water quality parameters (i.e. pH-value and dissolved oxygen concentration), measured at the start (0 and 24 hours) and at the end of the exposure intervals (24 and 48 hours), were within the acceptable limits. The validity criteria of the test guideline were fulfilled.

The EC50(48hours) with 95 % confidence limits has been determined to be 10.3 mg/L (Cl: 6.7 - 16 mg/L) based on geometric mean measured test item concentrations.