2,3-epoxybutane

Toxicity to microorganisms

Administrative data

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1999

Report date:

1999

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

1,2-epoxybutane

EC Number:

203-438-2

EC Name:

1,2-epoxybutane

Cas Number:

106-88-7

Molecular formula:

C4H8O

IUPAC Name:

2-ethyloxirane

Details on test material:

CHEMICAL NAME: 1,2-epoxybutane

Sampling and analysis

Analytical monitoring:

no

Test organisms

Test organisms (species):

activated sludge, domestic

Details on inoculum:

- Activated sludge from laboratory wastewater plants treating municipal sewage
- The inoculum was washed, brought to a concentration of 5 g/L dry substance and aerated for about 24 hours
- 50 mL were added to a total volume of 250 mL to obtain a concentration of 1 g/L dry substance in the test

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

30 min

Test conditions

Test temperature:

20°C

Details on test conditions:

TEST SUBSTANCE
- preparation of the stock solution: test substance was stirred for about 48 hours in deionized water
- the test substance hydrolysed and the hydrolysate was tested
- summary parameters of the test substance:
theoretical organic carbon (ThOC): 667 mg/g
total organic carbon (TOC) before hydrolysis: 600 mg/g; pH = 7.5 (not adjusted)
dissolved organic carbon (DOC) before hydrolysis: 582 mg/g
total organic carbon (TOC) after 48 hours hydrolysis: 591 mg/g; pH < 5 (adjusted to 7.6)
dissolved organic carbon (DOC) after 48 hours hydrolysis: 575 mg/g
remark: the deviation of 10%-14% to the ThOC is probably due to the hydrolysis.

TEST CONDITIONS
- incubation time: 30 min
- test vessels: Erlenmeyer vessels
- test volume: 250 ml
- synthetic medium: 8ml/Vessel 100-fold concentrated OECD medium
- oxygen concentration during aeration: > 2.5 mg/l
- oxygen concentration immediately before measurement: > 6.5 mg/l
- duration of the measurement of oxygen consumption: 8-10 min

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

30 min

Dose descriptor:

other: EC20

Effect conc.:

ca. 160 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Effect concentrations 2

Duration:

30 min

Dose descriptor:

other: EC80

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Effect concentrations 3

Duration:

30 min

Dose descriptor:

EC50

Effect conc.:

ca. 900 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Details on results:

VALIDITY CRITERIA
- deviation of blank controls <15%: yes
- EC50 of 3,5-dichlorophenol in the range of 5-30 mg/L: yes