Ethanone, 1-(3-methyl-2-benzofuranyl)-

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:

1997-11-07 to 1997-12-11

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

1992

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations: control, 0.01 mg/L, 0.02 mg/L, 0.04 mg/L, 0.08 mg/L, 0.16 mg/L and 0.32 mg/L (Nominal concentrations)
- Sampling method and Sample storage conditions before analysis: not reported

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: preparing a stock solution and then diluted to the desired test concentrations
- Controls: M4-medium

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Strain/clone: Daphnia magna STRAUS
- Source: cloned at the federal health office (BGA) in Berlin
- Age at study initiation: 0-24 hours
- Feeding during test :no feeding

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

14.9 °dH

Test temperature:

20.6-20.8 °C

pH:

7.9

Dissolved oxygen:

8.8-9.1

Salinity:

n.a.

Conductivity:

n.a.

Nominal and measured concentrations:

Nominal concentrations: 0 mg/L (control), 0.01 mg/L, 0.02 mg/L, 0.04 mg/L, 0.08 mg/L, 0.16 mg/L and 0.32 mg/L
measured concentrations at 0 h: <0.001 mg/L, 0.01 mg/L, 0.022 mg/L, 0.044 mg/L, 0.090 mg/L, 0.177 mg/L and 0.324 mg/L
measured concentrations at 48 h: <0.001 mg/L, 0.009 mg/L, 0.017 mg/L, 0.043 mg/L, 0.074 mg/L, 0.124 mg/L and 0.269 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: cylindrical test vessels with diameter 4.0 cm, height 6.5 cm
- Type: open
- Volume of solution: 20 mL
- Aeration: no
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2

TEST MEDIUM / WATER PARAMETERS
- Intervals of water quality measurement: 0h and 48h

VEHICLE CONTROL PERFORMED: no

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.1 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

0.01 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

0.3 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Immobilisation of control: 0%

Reported statistics and error estimates:

Probit analysis

Results:

Nominal concentration (mg/L)	Results after 24 hours and 48 hours
	Immobile daphnids				Oxygen [mg/L]	pH values	Temperature [°C]
	absolute		%
	24 h	48h	24h	48h	48h	48h	48h
control	0	0	0	0	9.1	7.9	20.7
0.01	0	0	0	0	9	7.9	20.6
0.02	0	1	0	5	9	7.9	20.6
0.04	3	5	15	25	8.9	7.9	20.8
0.08	2	5	10	25	8.8	7.9	20.7
0.16	2	11	10	55	9	7.9	20.7
0.32	0	20	0	100	9.8	7.9	20.6

Verification of the test concentration:

Nominal concentration (mg/L)	Measured concentrations
	0 h	48h
control	<0.001	<0.001
0.01	0.01	0.009
0.02	0.022	0.017
0.04	0.044	0.043
0.08	0.09	0.074
0.16	0.177	0.124
0.32	0.324	0.269

Concentrations were determined via GC-analysis.

Validity criteria fulfilled:

yes

Conclusions:

The value of 48h-EC50 was determined to be 0.1 mg/L based on measured concentration.

Executive summary:

There is one study, in which the short-term toxicity of test item to aquatic invertebrates was assessed according to Council Directive 67/548/EEC (1992) and GLP. In a static test, Daphnia magna was exposed to six concentration levels with paralell controls for 48 h. The test media were prepared by diluting a stock solution of 5 mg/L into 0 mg/L (control), 0.01 mg/L, 0.02 mg/L, 0.04 mg/L, 0.08 mg/L, 0.16 mg/L and 0.32 mg/L with a separating factor of 2. Test item concentrations were analytically verified by GC-analysis in fresh media at the start of exposure (0 h) and the end of exposure (48 h) in all concentration levels and the control.

The measured concentrations of the test item in fresh media were <0.001 mg/L (control), 0.01 mg/L, 0.022 mg/L, 0.044 mg/L, 0.090 mg/L, 0.177 mg/L and 0.324 mg/L. The measured concentrations at the end of exposure were <0.001 mg/L (control), 0.009 mg/L, 0.017 mg/L, 0.043 mg/L, 0.074 mg/L, 0.124 mg/L and 0.269 mg/L. After 24 h and 48 h of exposure, immobility was observed in all concentration levels and in the control. The derived EC50 (48 h) was 0.1 mg/L based on the measured concentrations

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.1 mg/L

Additional information

There is one study, in which the short-term toxicity of test item to aquatic invertebrates was assessed according to Council Directive 67/548/EEC (1992) and GLP.

In a static test, Daphnia magna was exposed to six concentration levels with parallel controls for 48 h. The test media were prepared by diluting a stock solution of 5 mg/L into 0 mg/L (control), 0.01 mg/L, 0.02 mg/L, 0.04 mg/L, 0.08 mg/L, 0.16 mg/L and 0.32 mg/L with a separating factor of 2. Test item concentrations were analytically verified by GC-analysis in fresh media at the start of exposure (0 h) and the end of exposure (48 h) in all concentration levels and the control. The measured concentrations of the test item in fresh media were <0.001 mg/L (control), 0.01 mg/L, 0.022 mg/L, 0.044 mg/L, 0.090 mg/L, 0.177 mg/L and 0.324 mg/L. The measured concentrations at the end of exposure were <0.001 mg/L (control), 0.009 mg/L, 0.017 mg/L, 0.043 mg/L, 0.074 mg/L, 0.124 mg/L and 0.269 mg/L. After 24 h and 48 h of exposure, immobility was observed in all concentration levels and in the control. The derived EC50 (48 h) was 0.1 mg/L based on the measured concentrations.