Chloroethane

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:

24 AUG - 26 AUG 1993

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP - Guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

GLP compliance:

yes

Analytical monitoring:

yes

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Ethylchlorid was given in excess in VE-water. The vessel was closed with a septum and incubated over 4 days at 4°C.
Preparation of test concentrations: head-space-vessels of 20 mL volume were filled with 19 mL synthetic freshwater and closed with as septum. All used instruments were cooled to 8°C. Adequate amounts of the stock solution were injected to each of the test vessels. The whole process was conducted at 8°C
- Controls: water control

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: waterflea
- Strain: clon 5
- Source: in-house culture
- Age at study initiation (mean and range, SD): below 24 h
- Method of breeding: parent daphnids were cultivated in Elendt medium in 1 L glass beakers. Animals were fed daily with Scenedesmus subspicatus.
- Feeding during test: no feeding

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test temperature:

20 +/- 1 °C

pH:

7.0 - 7.2 at test end

Dissolved oxygen:

8.3 - 8.6 at test end

Nominal and measured concentrations:

nominal: 0, 10, 20, 40, 80, 160 and 320 mg/L
mean measured: 0, 5.7, 11.1, 24.5, 46.5, 91, 217 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): closed
- Material, size, headspace, fill volume: round-bottom flasks filled with 10 mL test solution
- Aeration: none
- Type of flow-through (e.g. peristaltic or proportional diluter): static test
- No. of organisms per vessel: approximately 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- Biomass loading rate: 4 mL per test organism


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: synthetic freshwater. Composition: 294 mg/L CaCl2 x 2H2O; 123 mg/L MgSO4 x 7 H2O, 63 mg/L NaHCO3 and 5.5 mg/L KCl
- Ca/mg ratio: 4 : 1
- Intervals of water quality measurement: 48 h


OTHER TEST CONDITIONS
- Photoperiod: continuous darkness

Reference substance (positive control):

yes

Remarks:

potassium dichromate was tested in a separate study

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

58 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% C.L. 44 mg/L - 77 mg/L

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

91 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Results with reference substance (positive control):

- Mortality: 0.9 mg/L - 25% immobile daphnids after 24 h; 1.9 mg/L - 100% immobile daphnids after 24 h

Mean measured concentration [mg/L]	Test period (h)
	24 h	48 h
	Immobility [%]	Immobility [%]
0	0	0
5.7	0	0
11.1	5	5
24.5	0	7
46.5	15	20
91	50	85
217	100	100

Description of key information

EC50(48 h): 58 mg/L (meas. geom. mean)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

58 mg/L

Additional information

The acute toxicity of chloroethane (CAS 75-00-3) to aquatic invertebrates was tested in a guideline study following EU method C2. Daphnia magna were exposed to measured test concentrations of 5.7, 11.1, 24.5, 46.5, 91 and 217 mg/L under static conditions. The test concentrations were prepared by giving ethylchlorid in excess in VE-water. The vessel was closed with a septum and incubated over 4 days at 4°C. The test concentrations were prepared by filling head-space-vessels (20 mL volume) with 19 mL synthetic freshwater. The vessels were closed with a septum. At test termination an EC50 (48 h) of 58 mg/L (measured, geom. mean) were determined.