Chloroethane

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

24 AUG - 27 AUG 1993

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP - Guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

GLP compliance:

yes

Analytical monitoring:

yes

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Liquid ethylchlorid (liquid at 4 °C) was given in excess in 4 °C cold VE-water. The vessel was closed with a septum and incubated over 5 days at 4°C.
Preparation of test concentrations: head-space-vessels of 20 mL volume were filled with 10 mL nutrient solution 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):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Common name: green algae
- Source (laboratory, culture collection): originally obtained from "Institut für Wasser-, Boden- und Lufthygiene, Berlin", in-house culture
- Age of inoculum (at test initiation): 3 days

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test temperature:

24 +/- 2 °C

pH:

Test start: 8.3 - 8.6
Test end: 9.2 - 9.7

Nominal and measured concentrations:

nominal: 0, 20, 40, 80, 160, 320 and 640 mg/L
mean measured: 0, 7.7, 12, 30, 68, 132 and 319 mg/L

Details on test conditions:

TEST SYSTEM
- Type of flow-through (e.g. peristaltic or proportional diluter): static test
- Initial cells density: 2 x 10 exp 4 cells/mL
- Control end cells density: 49 x 10 exp 4 cells/mL
- No. of vessels per control (replicates): 17
- No. of vessels per vehicle control (replicates): 17


GROWTH MEDIUM
- Standard medium used: yes according to guideline 92/69/EWG


OTHER TEST CONDITIONS
- Photoperiod:continuous illumination
- Light intensity and quality: approximately 8000 lux


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: [counting chamber; electronic particle counter; fluorimeter; spectrophotometer; colorimeter]: photometer at 685 nm

Reference substance (positive control):

no

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

118 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

9.4 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

	Cell density (10^4cells/mL)
Mean measured concentration [mg/L]	Test period (h)
	0 h	24 h	48 h	72 h
Control	2	6	16	49
7.7	2	5	14	35
12	2	5	13	32
30	2	5	12	26
68	2	5	9	15
132	2	4	9	9
319	2	3	5	5

Description of key information

ErC50(72 h):118 mg/L (meas. geom. mean)

ErC10 (72 h): 9.4 mg/L (meas. geom. mean)

Key value for chemical safety assessment

EC50 for freshwater algae:

118 mg/L

EC10 or NOEC for freshwater algae:

9.4 mg/L

Additional information

The acute toxicity of chloroethane (CAS 75-00-3) to aquatic algae was tested in a guideline study following EU method C.3. Scenedesmus subspicatus was exposed to measured test concentrations of 7.7, 12, 30, 68, 132 and 319 mg/L under static conditions. The test concentrations were prepared by giving ethylchlorid in excess in VE-water. The vessels were closed with a septum and incubated over 5 days at 4°C. The test concentrations were prepared by filling head-space-vessels (20 mL volume) with 10 mL nutrient solution. The vessels were closed with a septum. At test termination EC50 (72 h) values of 118 mg/L (measured, geom. mean) were determined. The EC10 (72 h) value was 9.4 mg/L (measured, geom. mean).