1,2-epoxybutane

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:

1988-04-20 to 1988-04-22

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

Directive 84/449/EEC, C2

GLP compliance:

no

Analytical monitoring:

no

Test organisms (species):

Daphnia magna

Details on test organisms:

- source: Daphnia magna Straus was originally supplied from "Institut National de Recherche Chimique appliquee, France", and has been breeded from 1978 in the Laboratories of BASF
- age: 2 - 24 hours old

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

total hardness = 2.70

Test temperature:

18.85 - 20.85 °C

pH:

pH range over all concentrations and 0/48h: 7.71 - 7.95

Dissolved oxygen:

dissolved oxygen range over all concentrations and 0/48h: 8.15 - 8.71 mg/L

Salinity:

not applicable

Conductivity:

550 - 650 µS/cm

Nominal and measured concentrations:

Nominal: 7.81, 15.6, 31.2, 62.5, 125, 250 and 500 mg/L; measured values not available

Details on test conditions:

TEST CONDITIONS
- dilution water chemistry: according to guideline
- test water specifications: pH = 7.7 - 8.3
- conductivity = 550 - 650 uSiemens/cm,
- exposure vessels: reagent tubes with flat bottom
- 10 ml test volume
- light conditions: 16:8 hours, diffuse light (5 microeinstein/m*m*s (400-750 nm))
- number of replicates: four
- individuals / replicate: five
- dilution series with dilution water gave the following nominal test concentrations: 7.81, 15.6, 31.2, 62.5, 125, 250 and 500 mg/l.

STATISTICS
- moving average was used to calculate EC 50 (48h)
- method of Spearman Kaerber was used to calculate EC 50 (24h)

MEASUREMENTS
- pH values and dissolved oxygen: After 0 and 48 hours
- mobile daphnids: after 0, 3, 6, 24 and 48 hours

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

31 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

70 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 48.95 - 90.67

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

125 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Reported statistics and error estimates:

The EC50 after 48 hours was calculated according to Spearman-Kaerber.

CONCENTRATION RESPONSE RELATIONSHIP

Table 1: Mobile daphnids after 24 hours.

Concentration [mg/L]	0 h	3 h	6 h	24 h	48 h
0	20	20	20	20	20
7.81	20	20	20	20	20
15.6	20	20	20	20	20
31.2	20	20	20	20	19
62.5	20	20	20	20	19
125	20	20	20	17	0
250	20	20	20	0	0
500	20	20	19	0	0

 

Table 2: Measured oxygen concentrations.

Concentration [mg/L]	Oxygen concentration after
	0 h	48 h
7.81	8.66	8.6
15.6	8.61	8.52
31.2	8.6	8.59
62.5	8.6	8.55
125	8.57	8.15
250	8.55	8.23
500	8.47	8.22
0 (control)	8.71	8.59

EC-VALUES [mg/L]
24h-EC0 = 62.5
24h-EC50 = 159.66; 95% confidence level (142.87 - 178.42)
24h-EC100 = 250

 

CONSIDERATIONS ON VALIDITY OF TEST

The validity of the study was evaluated in accordance with the validity criteria given in the current OECD TG 202 (adopted 13th April 2004). In the control no daphnids were immobilised. Further, the dissolved oxygen concentration at the end of the test should was clearly above 3 mg/L in control and test vessels. Therefore, the study is regarded valid and acceptable for assessment.

Validity criteria fulfilled:

yes

Conclusions:

In a 48-hour acute toxicty test with Daphnia magna, the EC50 was determined at 70 mg/L, based on nominal test concentrations.

Description of key information

1.2 -epoxybutane is acutely harmful to aquatic invertebrates.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

70 mg/L

Additional information

The short-term toxicity of the test item to Daphnia magna was assessed in a guideline study according to EU Method C.2. Less than 24-hours old daphnids were exposed for 48 hours under static conditions to nominal test item concentrations of 7.81, 15.6, 31.2, 62.5, 125, 250 and 500 mg/L. In addition a negative control was performed. As a result, no daphnids were immobilized in the negative control. The dissolved oxygen concentration at the end of the test was clearly above 3 mg/L in control and test vessels. Based on immobilization the 48-hour EC50 was determined to be 70 mg/L (95% confidence interval: 48.95 – 90.67 mg/L). The test was evaluated to be valid in accordance with the criteria given in OECD TG 202 (adopted 13^th April 2004). The study is thus regarded acceptable for assessment.