1,2-epoxybutane

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Qualifier:

according to guideline

Guideline:

other: DIN 38412, Part 9, cell multiplication inhibitory test

GLP compliance:

no

Analytical monitoring:

no

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

- Scenedesmus subspicatus CHODAT SAG 86.81
- Supplier: SAG (Collection of algal cultures in Goettingen, GER)

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test temperature:

23°C

Nominal and measured concentrations:

- nominal test concentrations: 3.9, 7.8, 15.63, 31.25, 62.5, 125, 250 and 500 mg/L

Details on test conditions:

TEST CONDITIONS
- dilution water chemistry: according to OECD guideline 201
- exposure vessels: volume 10 mL
- number of Replicates: 4
- initial cell number: 10000 cells/mL

MEASUREMENTS
- in vivo chlorophyll-a-fluorescence (685 nm) after 0, 24, 48 and 72 hours

Duration:

72 h

Dose descriptor:

EC20

Effect conc.:

130 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 500 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC90

Effect conc.:

> 500 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

GROWTH RATE ACCORDING TO THE CONTROL [%]

Concentration	24 h	48 h	72 h
3.91	114	106	97.2
7.81	116	115	104
15.63	108	117	104
31.25	91.9	99.1	98.9
62.5	87.7	91.9	92.7
125	75.7	82.7	80.5
250	66.9	71.8	67
500	57.3	52.8	51.1

EC-VALUES [mg/L]
24h-EC20 = 100
24h-EC50 = >500
24h-EC100 = >500

48h-EC20 = 160
48h-EC50 = >500
48h-EC100 = >500

72h-EC20 = 130
72h-EC50 = >500
72h-EC100 = >500

Validity criteria fulfilled:

not specified

Conclusions:

In a 72-hour algae toxicity study, the EC50 (growth rate) was determined at > 500 mg/L, based on nominal test concentrations.

Description of key information

With high probability acutely not harmful to aquatic algae.

Key value for chemical safety assessment

EC50 for freshwater algae:

500 mg/L

Additional information

In an Algae Growth Inhibition test according to German national standards (DIN 38412, similar to OECD 201) with Desmodesmus subspicatus the EC50 (72h, growth rate) of the substance was determined to be > 500 mg/L.