Oxazolidine, 3-butyl-2-(1-ethylpentyl)-

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:

from 2005-06-21 to 2005-06-23

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)

Version / remarks:

updated 13 April 2004

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

adopted 31 July 1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

The concentration and stability of the test material in the test preparations were verified by chemical analysis at 0 and 48 hours. A Strata X solid phase extraction (SPE) cartridge was sequentially pre-conditioned with acetonitrile and water. A volume of test sample was eluted through the cartridge. The test material was eluted from the cartridge with acetonitrile and prepared for subsequent GC-FID analysis.

Vehicle:

no

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Source: in-house laboratory cultures
- Age at study initiation: approximately 24 h

ACCLIMATISATION
- Type and amount of food: suspension of algae (Chlorella sp.)
- Feeding frequency: daily
Adult Daphnia were maintained in polypropylene vessels containing approximately 2 litres of reconstituted water in a temperature controlled room at approximately 20 °C. The lighting cycle was controlled to give a 16 hours light and 8 hours darkness cycle with 20 minutes dawn and dusk transition periods.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

no

Hardness:

The reconstituted water had an approximate theoretical total hardness of 250 mg/L as CaCO3.

Test temperature:

21.1 - 21.6 °C

pH:

Control: 7.9
1.0 mg/L: 7.8 - 7.9
1.8 mg/L: 7.8 - 7.9
3.2 mg/L: 7.8 - 7.9
5.6 mg/L: 7.8 - 8.0
10 mg/L: 7.9 - 8.1
18 mg/L: 7.9 - 8.7
32 mg/L: 8.0 - 8.5
56 mg/L: 8.2 - 8.8
100 mg/L: 8.5 - 9.2

Dissolved oxygen:

Control: 96 -100 %ASV
1.0 mg/L: 94 -100 %ASV
1.8 mg/L: 93 -100 %ASV
3.2 mg/L: 94 -99 %ASV
5.6 mg/L: 96 -100 %ASV
10 mg/L: 96 -100 %ASV
18 mg/L: 96 -100 %ASV
32 mg/L: 96 -98 %ASV
56 mg/L: 97 -99 %ASV
100 mg/L: 97 - 100 %ASV
ASV = Dissolved oxygen concentration expressed as a percentage of Air Saturation Value

Salinity:

not applicable

Nominal and measured concentrations:

Nominal: 1.0, 1.8, 3.2, 5.6, 10, 18, 32, 56, 100 mg/L
Due to the rapid hydrolysis of the test item, steady measured concentrations of the test item were not achivable. The hydrolysis products could not be detected by the analytical method due to possible but unconfirmed adsorption to surfaces.

Details on test conditions:

TEST SYSTEM
- Test vessel: 250 mL glass jars containing approximately 250 mL of test preparation
- No. of organisms per vessel: 10
- No. of vessels per concentration: 2 (dupliclate test vessels)
- No. of vessels per control (replicates): 2 (dupliclate test vessels)

TEST MEDIUM
- Source/preparation of dilution water: reconstituted water

OTHER TEST CONDITIONS
- Adjustment of pH: The reconstituted water had a pH of 7.8 ± 0.2 adjusted (if necessary) with NaOH or HCl
- Photoperiod: 16 hours light and 8 hours darkness for a period of 48 hours with 20 minute dawn and dusk transition periods

EFFECT PARAMETERS MEASURED :
Mobility

TEST CONCENTRATIONS
- Range finding study: yes
- Test concentrations in range finding study: 0.10, 1.0, 10 and 100 mg/L
- Results used to determine the conditions for the definitive study: Yes, the test concentrations to be used in the definitive test were determined by the preliminary range-finding test

Reference substance (positive control):

yes

Remarks:

potassium dichromate (0.32, 0.56, 1.0, 1.8 and 3.2 mg/L)

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

21 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95 % confidence limits: 18 - 25 mg/L

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

9.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95 % confidence limits: 7.8 - 11 mg/L

Duration:

24 h

Dose descriptor:

NOEC

Effect conc.:

<= 10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

<= 3.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

Due to the rapid hydrolysis of the test item, steady measured concentrations of the test item were not achievable. The hydrolysis products could not be detected by the analytical method due to possible but unconfirmed adsorption to surfaces.

Results with reference substance (positive control):

The results from the positive control with potassium dichromate were within the normal range for this reference material. The mean 48-hour EC50 value calculated from all positive controls was 0.82 mg/L.

Reported statistics and error estimates:

not applicable

Validity criteria fulfilled:

yes

Conclusions:

The acute toxicity of the test material to the freshwater invertebrate Daphnia magna has been investigated and gave a 48-hour EC50 value of 9.5 mg/L with 95 % confidence limits of 7.8 -11 mg/L. The No Observed Effect Concentration at 48 hours was 3.2 mg/L.

Executive summary:

A study was performed to assess the acute toxicity of the test material to Daphnia magna, according to OECD Guideline 202 and EU method C.2. Following a preliminary range-finding test, twenty daphnids (2 replicates of 10 animals) were exposed to an aqueous solution of the test material at concentrations of 1.0, 1.8, 3.2, 5.6, 10, 18, 32, 56 and 100 mg/L for 48 hours at a temperature of 21.1 to 21.7 °C under static test conditions. The number of immobilised Daphnia were recorded after 24 and 48 hours.

A positive control conducted approximately every six months used potassium dichromate as the reference material. Daphnia magna was exposed to an aqueous solution of the reference material at concentrations of 0.32, 0.56, 1.0, 1.8 and 3.2 mg/L for 48 hours at a temperature of approximately 20 °C under static test conditions. Immobilisation and any adverse reactions to exposure were recorded after 3, 24 and 48 hours.

Due to the rapid hydrolysis of the test item, steady measured concentrations of the test item were not achievable. The hydrolysis products could not be detected by the analytical method due to possible but unconfirmed adsorption to surfaces.

The 48-hour EC50 obtained for the test material to Daphnia magna based on nominal test concentrations of parent test material was 9.5 mg/L with 95 % confidence limits of 7.8 - 11 mg/L. The No Observed Effect Concentration was 3.2 mg/L.

Description of key information

The acute toxicity of the test material to the freshwater invertebrate Daphnia magna has been investigated and gave a 48-hour EC50 value of 9.5 mg/L with 95 % confidence limits of 7.8 - 11 mg/L. The No Observed Effect Concentration at 48 hours was 3.2 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

9.5 mg/L

Additional information

A study was performed to assess the acute toxicity of the test material to Daphnia magna, according to OECD Guideline 202 and EU method C.2. Following a preliminary range-finding test, twenty daphnids (2 replicates of 10 animals) were exposed to an aqueous solution of the test material at concentrations of 1.0, 1.8, 3.2, 5.6, 10, 18, 32, 56 and 100 mg/L for 48 hours at a temperature of 21.1 to 21.7 °C under static test conditions. The number of immobilised Daphnia were recorded after 24 and 48 hours.

A positive control conducted approximately every six months used potassium dichromate as the reference material. Daphnia magna was exposed to an aqueous solution of the reference material at concentrations of 0.32, 0.56, 1.0, 1.8 and 3.2 mg/L for 48 hours at a temperature of approximately 20 °C under static test conditions. Immobilisation and any adverse reactions to exposure were recorded after 3, 24 and 48 hours.

The 48-hour EC50 obtained for the test material to Daphnia magna based on nominal test concentrations of parent test material was 9.5 mg/L with 95 % confidence limits of 7.8 - 11 mg/L. The No Observed Effect Concentration was 3.2 mg/L.

Due to the rapid hydrolysis of the test item, steady measured concentrations of the test item were not achievable. The hydrolysis products could not be detected by the analytical method due to possible but unconfirmed adsorption to surfaces.