2,3-dihydrothieno[3,4-b][1,4]dioxine

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:

22.2.-11.3.2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: This study was carried out in accordance with internationally valid GLP principles.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

yes

Remarks:

See overall remarks.

GLP compliance:

yes

Test material

Reference

Name:

Unnamed

Type:

Constituent

Details on test material:

- Name of test material (as cited in study report): 3,4-Ethylenedioxythiophene
- Comercial name. EDOT
- Substance type: pure organic substance
- Physical state: liquid near colourless to pale yellow
- Analytical purity: > 99%
- Lot/batch No.: 091201
- Expiration date of the lot/batch: 21.1.2011
- Storage condition of test material: Keep in dark at room temperature. Stored in amber glass bottles under the argon atmosphere. Minimalize time for handling with substance without protective argon atmosphere as possible. Maximal time without protective atmosphere is 30 min.

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Test solution nominal concentration: 0.5, 1, 2, 5, 10, 23, 50 mg/L
- Sample storage conditions before analysis: All samples for analysis were delivered in transport box to analytical laboratory immediately after preparation and after each test period (0-24 hours and 24-48 hours). An analysis of samples was started immediately after delivery. All samples were stored at laboratory temperature.

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: The stock solution of the test substance was prepared in the dilution water. 100 mg of the test substance was weighed into 1000 mL of the dilution water for the preliminary test and the full semi-static test. The stock solutions were stirred for period 30 min. on a magnetic stirrer.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Strain: Straus
- Source: own laboratory breeding
- Age at study initiation (mean and range, SD): young daphnia born in 24 hr
- Method of breeding: aperiodic parthenogenesis
- Feeding during test: no

ACCLIMATION
- Acclimation period: The grow-up gravid females are separated into dilution water. Young daphnia born in 24 hours are segregated to the handling container from which they entered the experiment.
- Acclimation conditions: same as test
- Type and amount of food: a mixture of algae
- Feeding frequency:
- Health during acclimation (any mortality observed): At handling a care should be taken of not to penetrate the air under animal’s shell.

Study design

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test conditions

Hardness:

Test solution 1:
Content of (Ca+Mg) in dilution water 2.47 mmol/L
Test solution 2 (renewal the test solutions after 24 hrs):
Content of (Ca+Mg) in dilution water 2.48 mmol/L

Test temperature:

20+/-2 °C

pH:

7.8

Dissolved oxygen:

Test solution 1: 8.5 mg.L-1 at temperature of 20.3 °C
Test solution 2 (renewal the test solutions after 24 hrs): 9.1 mg.L-1 at temperature of 20.5 °C

Nominal and measured concentrations:

See table 2

Details on test conditions:

TEST SYSTEM
- Test vessel: open beakers (50 mL)
- Aeration: no
- Renewal rate of test solution: The test solutions were renewed after 24 hrs.
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2
- Biomass loading rate: one daphnia per 5 mL of test solution (least 2 ml per individual)

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Standard dilution water was prepared just before the test.
- The dilution water should be of pH 7.8 +/- 0.2. The sum of Ca + Mg ions should be approx. 2.5 mmol.L-1.
- Total organic carbon:
- Ca/mg ratio: 2.48 mmol.L-1
- Conductivity: 0.171 mS.m-1

OTHER TEST CONDITIONS
- Lighting: natural variation of daily light and dark

EFFECT PARAMETERS MEASURED: immobilisation of daphnia after 24 and 48 hours

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2.2
- Range finding study:
The preliminary test was performed in range of test substance nominal concentrations 1 – 100 mg•L-1. The analytical results from the preliminary test showed, that the test substance 3,4-Ethylenedioxythiophene was not stable in dilution water in conditions of the test. Based on the instability and toxicity of the test substance found in preliminary test, the full semi-static test was performed in appropriate concentration range.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

19.4 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 13.5-25.3 mg/L

Effect concentrations 2

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

13 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 11.7-14.4 mg/L

Effect concentrations 3

Duration:

24 h

Dose descriptor:

NOEC

Effect conc.:

0.95 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 4

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

0.95 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 5

Duration:

24 h

Dose descriptor:

EC100

Effect conc.:

> 41.7 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 6

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

> 41.7 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

mobility

Results with reference substance (positive control):

- Results with reference substance valid: yes. The immobilisation of test species in reference substance solution expressed as EC50 fits into the accepted range in the interlaboratory tests.
- EC50: 48 hour – EC50 = 0.98 mg.L-1 (95 % confidence limit: 0.74 – 1.23 mg.L-1).

Any other information on results incl. tables

EVALUATION OF RESULTS

The value of EC50 was calculated by means of software “Toxicita”(product of Water Research Institute, Ostrava, Czech Republic). The NOEC and EC100 values are identified by direct observation.

Time weighted mean concentrations were used for all evaluations and results.

Applicant's summary and conclusion

Validity criteria fulfilled:

no

Remarks:

See Overall remarks.

Executive summary:

The test substance, 3,4-Ethylenedioxythiophene, was tested in acute immobilisation test on Daphnia magna.

The test was performed according to method C.2 – Daphnia sp. Acute Immobilisation Test, Council Regulation (EC) No. 440/2008, published in O.J.L 142, 2008.

The preliminary test was performed in range of test substance nominal concentrations 1 – 100 mg.L-1. The analytical results from the preliminary test showed, that the test substance 3,4-Ethylenedioxythiophene was not stable in dilution water in conditions of the test. Based on the instability and toxicity of the test substance found in preliminary test, the full semi-static test was performed in appropriate concentration range.

The full semi-static test was performed in range of test substance nominal concentrations 0,5 - 50 mg.L-1. The test solutions were renewed after 24 hours. The test substance content was measured at each test concentration at the start of the test, after 24 hours (before and after renewal), and at the end of the test.

For all evaluations and results time weighted mean concentrations were used.

Test results:

24 hour - EC50 = 19.4 mg.L-1 (95% confidence limit: 13.5 – 25.3 mg.L-1) (time-weighted mean concentration)

48 hour - EC50 = 13.0 mg.L-1 (95% confidence limit: 11.7 – 14.4 mg.L-1) (time-weighted mean concentration)

24 hour - NOEC = 0.95 mg.L-1 (time-weighted mean concentration)

48 hour - NOEC = 0.95 mg.L-1 (time-weighted mean concentration)

24 hour - EC100 > 41.7 mg.L-1 (time-weighted mean concentration)

48 hour - EC100 = 41.7 mg.L-1 (time-weighted mean concentration)