Methyl valerate

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Batch number: 40850230

Analytical monitoring:

yes

Remarks:

GC analysis

Details on sampling:

- Control: at 48 hours (on 2017-04-05)
- Test concentration/s: 100 mg/L in the freshly prepared media (on 2017-04-04 and 2017-04-05) and in the media after 24 h of exposure (on 2017-04-05 and 2017-04-06) according to semi-static conditions

Vehicle:

no

Details on test solutions:

Pre-treatment of test item and preparation of test item concentrations:
- 114 μL (100 mg/L) of the test item were added to 1 litre of dilution water on 2017-04-04 and 2017-04-05 and stirred for 2 h on a magnetic stirrer
- The pH was measured to be 6.8 on 2017-04-04 and 6.9 on 2017-04-05
- 50 mL of the solution were taken and diluted with 0.5 mL of dilution water resulting in a final concentration of 100 mg/L

Test organisms (species):

Daphnia magna

Details on test organisms:

- Age: parthenogenetic females
- Source: Strain of Bundesgesundheitsamt Berlin
- Maintenance and Acclimatisation: A population of parthenogenetic females of synchronized age structure has been maintained for more than 20 years in the test facility under constant temperature conditions (20 +/- 2 °C) at a 16 : 8 hour light-dark photoperiod (light intensity: < 20 μE x m-2 x s-1). The culture water (so-called 'M4 medium') was partly renewed once a week. The Daphnia were exclusively fed unicellular green algae (Desmodesmus subspicatus) 'ad libitum'. Mortalities of parent Daphnia during the culture period were recorded daily in a semi-quantitative way. The neonates were separated from their parent Daphnia by filtration prior to the acute test.

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

14.2 °dH (253 mg/L CaCO3)

Test temperature:

20.0 - 20.5 °C

pH:

6.9-7.1

Dissolved oxygen:

7.8 - 8.1 mg/L (concerning the highest test concentration)

Salinity:

n.a.

Conductivity:

No data

Nominal and measured concentrations:

100 mg/L (n): Effective concentrations (GC-analysis) ranged from 86.4 % to 94.3 % in the freshly prepared media and from 35.8 % to 50.1 % in the media after 24 hours of exposure. Geometric mean concentrations of 65.8 mg/L and 61.8 mg/L were determined for 24 and 48 h respectively.

Details on test conditions:

EXPOSURE CONDITIONS:
- Test vessels: 100 mL glass beakers covered with watch glasses holding 5 neonates in 50 mL of the test medium
- Experimental design: 1 test concentration plus 1 control; 5 neonates per vessel, 4 replicates per concentration/control; no feeding during the exposure period
- Method of initiation: neonates were placed in prepared media
- Photoperiod: 16 h light : 8 h dark
- Temperature of incubation unit: 19.6 to 20.0 °C
- Aeration: none
- Test item concentration/s: 100 mg/L
- Method of administration: direct weighing
- Replicates: 4 per each test item concentration and control
- Medium renewal: daily
- Criteria of effects: The criterion of adverse effects used in this study was the item-induced alteration of the normal mobility behaviour and the loss of locomotory actions of the neonates, observed at 24 and 48 hours

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 61.8 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

Effective concentrations ranged from 4.96 % to 5.04 % of nominal values at 0 hours and from 4.75 % to 4.99 % of nominal values at 48 hours.

Validity criteria fulfilled:

yes

Remarks:

Immobilisation and other abnormalities in the controls did not exceed 10% by the end of the test; dissolved oxygen concentration remained above 3 mg/L throughout the exposure period

Conclusions:

After 48 hours of exposure no toxic effects against Daphnia were observed at a limit test concentration of 61.8 mg/L.

Executive summary:

A study was conducted in accordance with the Council Regulation (EC) No 440/2008, Method C.2 ‘Acute toxicity for Daphnia’ (2008) which is equivalent to OECD Guideline for Testing of Chemicals No. 202 'Daphnia sp., Acute Immobilisation Test' (adopted April 13, 2004). The study was performed to assess the acute toxicity to Daphnia magna STRAUS under semi-static conditions. The Daphnia were exposed to a limit test concentration of nominally 100 mg/L of methyl valerate dissolved in dilution water. Auxiliaries used to prepare the test media were a magnetic stirrer. Observations were made on the swimming ability and the immobilisation rate, respectively, after 24 and 48 hours of exposure. After 48 hours of exposure an EC50 of higher than 61.8 mg/L was determined. The results are expressed in terms of geometric mean measured concentrations. Effective concentrations ranged from 86.4 % to 94.3 % in the freshly prepared media and from 35.8 % to 50.1 % in the media in 24 hours old media.

No toxic effects against Daphnia were observed at a limit test concentration of 61.8 mg/L after 48 h under exposure conditions. This toxicity study is classified as acceptable and satisfies the guideline requirements for the acute Daphnia study.

Description of key information

The acute toxicity to daphnia magna was investigated in a semi-static GLP study following OECD 202. After 48 hours of exposure no toxic effects against Daphnia were observed at a limit test concentration of 61.8 mg/L. The results are expressed in terms of geometric mean measured concentrations.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

61.8 mg/L

Additional information

"Should read: 48 h EC50: > 61.8 mg/L"

Effective concentrations ranged from 86.4 % to 94.3 % in the freshly prepared media and from 35.8 % to 50.1 % in the media after 24 hours.