2,2'-[(1-methylethylidene)bis(cyclohexane-4,1-diyloxymethylene)]bisoxirane

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:

10 October 2004 to 10 January 2005

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

1984 Part I - 24h EC50 Acute Immobilisation Test

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

1992

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.1010 (Aquatic Invertebrate Acute Toxicity Test, Freshwater Daphnids)

Version / remarks:

1996

Deviations:

no

Qualifier:

according to guideline

Guideline:

ISO 6341 (Water quality - Determination of the Inhibition of the Mobility of Daphnia magna Straus (Cladocera, Crustacea))

Version / remarks:

1989

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: International Standard ISO/DIS 10706

Version / remarks:

Water quality - Determination of long term toxicity of substances to Daphnia magna STRAUS

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- At the beginning (after 0 h) and after 24 h (new test solutions) samples from vessels without daphnids and after 24h (old test solutions) and at the end of the exposition (after 48 h) samples from vessels with daphnids were analysed.
- The concentration control analyses were performed with test solutions of the following nominal concentrations (mg/L) of the test material: 0, 10, 5, 2.5, 1.25 and 0.625.

Vehicle:

no

Details on test solutions:

- The test material was stirred in M4 medium for about 20 hours at 20 ± 2°C. Undissolved test material was removed by centrifugation (approximately 20 min at about 17700 G). The eluate appeared colourless-clear.
- The concentration of the stock solutions were: 1.3 mg/2L, 2.6 mg/2L, 2.6 mg/1L, 5.4 mg/L and 10.1 mg/L (h0). 1.3 mg/2L, 2.6 mg/2L, 2.6 mg/1L, 5.1 mg/L and 10.2 mg/L (h24).

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Strain/clone: STRAUS
- Age at beginning of test: 2-24 h (starting with the 3rd breed of parent animals)
- Age of stock animals: 2 - 4 weeks
- Feeding during test: none

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

2.20 – 3.20 mmol/L

Test temperature:

19.1 - 19.8°C

pH:

7.7 - 8.1

Dissolved oxygen:

8.6 - 9.2 mg/L

Conductivity:

550 - 650 µS/cm

Nominal and measured concentrations:

Nominal: 0.625, 1.25, 2.5, 5 and 10 mg/L.
Mean Measured: 0.598, 1.223, 2.448, 4.678 and 9.190 mg/L
Measured concentrations were within 86.6 - 109 % of the nominal values at 0, 24 and 48 hours.

Details on test conditions:

TEST SYSTEM
- Test vessel: Test tubes (glass) sealed with gas impermeable teflon caps (nominal volume 23 mL).
- Fill volume: approx. 23 mL
- Renewal rate of test solution: after 24 hours
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- Biomass loading rate: 0.22 animals/mL

TEST MEDIUM / WATER PARAMETERS
- A synthetic fresh water was used for culture and test purposes (M4 medium).
Properties of this medium:
- Total hardness: 2.20 - 3.20 mmol/L
- Alkalinity up to pH 4.3 : 0.80 - 1.00 mmol/L
- Molar ratio Ca:Mg: about 4:1
- Conductivity: 550 - 650 µS/cm
- After preparation the M4 medium was aerated for approximately 24 h until saturation with oxygen was reached.
- Intervals of water quality measurement: Temperature was measured continuously during the whole test period in a separate vessel. pH and oxygen were measured after 0 and 24 h (new test solutions) in an additional replicate without daphnids and after 24 and 48 h (old test solutions) in replicate 1 of each tested concentration.

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: Artificial light, type warm white (OSRAM L58 W31) day: night rhythm = 16:8 h
- Light intensity: About 1- 8 µE/(m².s) at a wave length of 400 - 750 nm

EFFECT PARAMETERS MEASURED: Swimming ability of the test animals was observed visually after 0, 24 and 48 hours.

RANGE-FINDING STUDY
- The test concentrations were determined in a range finding test (non GLP).

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

3.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: (95 % confidence limits: 2.65-3.84 mg/L)

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

1.25 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

2.46 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: (95 % confidence limits: 2.04 - 2.92 mg/L)

Duration:

24 h

Dose descriptor:

EC0

Effect conc.:

1.25 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EC100

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

VALIDITY CRITERIA
- In the control the immobilisation was ≤ 10%.
- In the control no daphnids were captured in a surface film.
- The O2-concentration was > 3 mg/L in all tested replicates.
- The EC50 (24h) of the control substance potassium dichromate was 1.07 mg/L
The test is valid.

Results with reference substance (positive control):

- The EC50(24h) of the control substance potassium dichromate was 1.07 mg/L

Reported statistics and error estimates:

For the statistical calculation of the EC50 the probit method (p ≤ 0.05) was used.

Table 1: Number of mobile daphnids

Nominal Concentration (mg/L)	Parallel 1 (h)			Parallel 2 (h)			Parallel 3 (h)			Parallel 4 (h)			∑(h)
	0	24	48	0	24	48	0	24	48	0	24	48	24	48
Control	5	5	5	5	5	5	5	5	5	5	5	5	20	20
10	5	0	0	5	0	0	5	0	0	5	0	0	0	0
5	5	0	0	5	1	0	5	1	0	5	1	1	3	1
2.5	5	5	4	5	4	3	5	4	0	5	1	1	14	8
1.25	5	5	5	5	5	5	5	5	5	5	5	5	20	20
0.625	5	5	5	5	5	5	5	5	5	5	5	5	20	20

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions of this study, the 48 hour EC50 was determined to be 2.46 mg/L (95% confidence limits: 2.04 - 2.93 mg/L).

Executive summary:

The toxicity of the test material to aquatic invertebrates was investigated in accordance with the standardised guidelines OECD 202, EU Method C.2, OPPTS 850.1010, ISO 6341 and ISO/DIS 10706, under GLP conditions.

Determination of the acute effect on the swimming ability of the water flea Daphnia magna STRAUS was assessed in a 48-hour semi-static test.

The test material was tested in the range of concentrations between 0.625 and 10 mg/L, the dilution factor was 2. Those animals were considered to be immobile which were unable to swim within 15 seconds even after gentle agitation of the test vessel.

The test was performed in closed test system performed with a change of the test solutions after 24 h test duration. The recovery rate in the concentration control gas chromatography analysis was between 86.6 and 109%.

All of the validity criteria of the test were met.

Under the conditions of this study, the 48 hour EC50 was determined to be 2.46 mg/L (95% confidence limits: 2.04 - 2.93 mg/L).

Description of key information

Under the conditions of the study, the 48 hour nominal EC50 was 2.46 mg/L (95% confidence limits: 2.04-2.93 mg/L).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

2.46 mg/L

Additional information

The toxicity of the test material to aquatic invertebrates was investigated in accordance with the standardised guidelines OECD 202, EU Method C.2, OPPTS 850.1010, ISO 6341 and ISO/DIS 10706, under GLP conditions. The study was awarded a reliability score of 1 in accordance with the criteria set forth by Klimisch et al. (1997).

Determination of the acute effect on the swimming ability of the water flea Daphnia magna STRAUS was assessed in a 48-hour semi-static test.

The test material was tested in the range of concentrations between 0.625 and 10 mg/L, the dilution factor was 2. Those animals were considered to be immobile which were unable to swim within 15 seconds even after gentle agitation of the test vessel.

The test was performed in closed test system performed with a change of the test solutions after 24 h test duration. The recovery rate in the concentration control gas chromatography analysis was between 86.6 and 109%.

All of the validity criteria of the test were met.

Under the conditions of the study, the 48 hour EC50 was determined to be 2.46 mg/L (95% confidence limits: 2.04 - 2.93 mg/L).