Ethyl isovalerate

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:

1999-04-30 to 1999-06-10

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: analysis of the only test concentration plus a control at test start and after 48 hours of exposure.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: a 1.6 fold amount of the maximum water solubility (s= 73 mg/L at 20 °C) was taken (120 mg/L). Test substance was weighed into water, treated for 60 seconds at 8000 rpm. with an ultra-turrax and afterwards stirred for 24 hours an a magnetic stirrer.
- Controls: yes, M4-Medium according to Elendt and BGA (1992)
- Evidence of undissolved material (e.g. precipitate, surface film, etc): resulting emulsion was filtered using a folded filter of the pore size 7-12 µm to remove undissolved particles

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna STRAUS
- Age at study initiation: 0-24 hours
- Other: Origin of species: cloned at the Federal Health Office (BGA) in Berlin and Test animals: laboratory bred at Bayer AG Leverkusen

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

14.9°dH (dilution water)

Test temperature:

19.6°C (48 h)

pH:

7.9 (48 h)

Dissolved oxygen:

5.5 - 8.9 mg/L (48 h)

Nominal and measured concentrations:

- nominal: 0 (control), 73 mg/L
- measured: 0 h: 4.5 (control), 67.5 mg/L; 48 h:

Details on test conditions:

TEST SYSTEM
- Test vessel: so called "Karlsruher bottles" with stoppers
- Type: closed
- Material, size, headspace, fill volume: 250 - 300 mL and had space
- Aeration: not ventilated
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: M4-Medium according to Elendt and BGA (1992)
- Culture medium different from test medium: no
- Other: Water hardness: 14.9 [°dH]

OTHER TEST CONDITIONS
- Photoperiod: 16 hours light / 8 hours dark

EFFECT PARAMETERS MEASURED (with observation intervals if applicable):
- number of immobile daphnids after 24 h and 48 h

Reference substance (positive control):

no

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

>= 73 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: The mean recovery is 92% based on TOC analysis; nominal concentrations are used for assessment

Key result

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

>= 67 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Table 1: Results after 24 and 48 h

Nominal concentration [mg/L]	Results after 24 h and 48 h
	Immobile daphnids				Oxygen content [mg/L] after 48 h	pH after 48 h	Temperature [°C] after 48 h
	absolute		%
	24 h	48 h	24 h	48 h
0 (control)	0	0	0	0	8.9	7.9	19.6
73	0	0	0	0	5.5	7.9	19.6

Validity criteria fulfilled:

yes

Conclusions:

The toxicity of the test item on Daphnia magna was tested in a limit test according to OECD Test guideline 202 and in compliance with GLP. Individuals were exposed to 73 mg/L nominal concentration, equivalent with a measured concentration of 67 mg/L. The test concentrations were analytically verified by TOC determination. The EC0 value obtained for the test substance was >= 73 mg/L (nominal) and >= 67 mg/L (measured).

Description of key information

EC0 (48 h): >= 67 mg/L based on mean measured concentrations.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

67 mg/L

Additional information

The toxicity of the test item on Daphnia magna was tested in a reliable limit test according to OECD 202 and in compliance with GLP. Individuals were exposed to 73 mg/L nominal concentration, equivalent with a measured concentration of 67 mg/L. The test concentrations were analytically verified by TOC determination. The EC0 value obtained for the test substance was >= 73 mg/L (nominal) and >= 67 mg/L (measured).