3-Methoxy-3-methylbutyl acetate

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

27 August 2007 - 31 August 2007

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: OECD Gudance Document 23 "Guidance Document on Aquatic Toxicity Testing of Difficult Substances and Mixtures" (September 2000)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 35.0, 45.5, 59.2, 76.9 and 100 mg/L
- Sampling method: The test solutions for analysis were taken out from the middle layer in the test vessels. The concentration of the test item and 3-methoxy-3-methylbutan-1-ol was analyzed by GC. The concentration of acetic acid was analyzed by HPLC.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Desired amount of test sample and dilution water in the test vessels were mixed and stirred to prepare the test solutions.
- Controls: Only the dilution water was used as control.

Test organisms (species):

Oryzias latipes

Details on test organisms:

TEST ORGANISM
- Common name: Medaka
- Source: Laboratory
- Age at study initiation: 5 months
- Length at study initiation (length definition, mean, range and SD): 2.0 +/- 1.0 cm

ACCLIMATION
- Acclimation period: 34 days
- Acclimation conditions (same as test or not): flow-through condition under the same water quality and temperature conditions.
- Type and amount of food during acclimation: feed mixture for carp, not fed for 25h before the start of exposure.
- Health during acclimation (any mortality observed): 0% mortality observed during the 7 days before the start of exposure.

FEEDING DURING TEST
- Food type: Test organisms were not fed during the exposure.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

37.0 mg/L

Test temperature:

24 +/- 1 °C

pH:

7.7 (at 24 °C), 7.6 - 7.9 during the test

Dissolved oxygen:

> 60 %

Salinity:

no data

Conductivity:

15.5 mS/m

Nominal and measured concentrations:

Nominal: 35.0, 45.5, 59.2, 76.9 and 100 mg/L
Measured (test start): 36.4, 45.3, 60.6, 82.1, 109 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass tanks
- Type (delete if not applicable): glass cover
- Material, size, headspace, fill volume: 7.8 L glass tank (diameter: 24 cm, depth: 28 cm)
- Aeration: No
- Renewal rate of test solution (frequency/flow rate): renewal every 24h
- No. of organisms per vessel: 8 fish/test level
- No. of vessels per concentration (replicates): One replicate/test level
- No. of vessels per control (replicates): One replicate/test level (control)

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Dechlorinated tap water
- Total organic carbon: < 0.1 mg/L
- Ca/mg ratio: 3.7

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: 16 h / 8 h
- Light intensity: Artificial light of white fluorescent lamp

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): Mortality and visible abnormality were observed at 3, 24, 48, 72 and 96 hours after the start of the test in each exposure level.

TEST CONCENTRATIONS
- Range finding study : Yes
- Test concentrations: Not known
- Results used to determine the conditions for the definitive study: Yes

Reference substance (positive control):

no

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

84.9 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: LC50 value estimated by the binomial test.

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

73.8 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: LC50 value estimated by the binomial test.

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

59.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks:

No behavioural anomalies seen at this level, either.

Details on results:

- Behavioural abnormalities: One surviving fish dosed at 76.9 mg/L was seen swimming at the surface, was found to have a comlpete loss of equilibrium, and reduced activity after 72 hours.
- Mortality of control: No mortality was seen in the control group.

Reported statistics and error estimates:

Binominal test

Validity criteria fulfilled:

yes

Conclusions:

The 96-hour LC50 value in Medaka (Oryzias latipes) for the test item was determined to be 73.8 mg/L. The highest concentration (NOEC) showing no mortality after 96 hours was 59.2 mg/L.

Executive summary:

An acute fish toxicity test was conducted to assess the effect of the test material on fish. The study was conducted according to OECD 203 and in compliance with GLP.

Test groups of eight Medaka (Oryzias latipes) per group were exposed to test medium containing the test material at concentrations of 0 (control), 35.0, 45.5, 59.2, 76.9, and 100 mg/L. The test was conducted over 96h, and the test medium was replaced at 24h-intervals. The fish were observed for mortality and abnormal behavious at 3h from the start of the exposure period, and then at 24, 48, 72, and 96h from the start of exposure. Concentrations of the test material and its hydrolysis products 3-methoxy-3-methylbutan-1-ol and acetic acid were verified by GC-FID and HPLC. Mortalities were seen in the 76.9 and 100 mg/L dose levels; all fish at the 100 mg/mL level had died by the 48h timepoint. The 96h LC50 value in Medaka (Oryzias latipes) for the test item was determined to be 73.8 mg/L. The highest concentration (NOEC) showing no mortality after 96h was 59.2 mg/L.

Description of key information

The 96h LC50 value in Medaka (Oryzias latipes) for the test item was determined to be 73.8 mg/L. The highest concentration (NOEC) showing no mortality after 96h was 59.2 mg/L.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

73.8 mg/L

Additional information

An acute fish toxicity test was conducted to assess the effect of the test material on fish. The study was conducted according to OECD 203 and in compliance with GLP.

Test groups of eight Medaka (Oryzias latipes) per group were exposed to test medium containing the test material at concentrations of 0 (control), 35.0, 45.5, 59.2, 76.9, and 100 mg/L. The test was conducted over 96h, and the test medium was replaced at 24h-intervals. The fish were observed for mortality and abnormal behavious at 3h from the start of the exposure period, and then at 24, 48, 72, and 96h from the start of exposure. Concentrations of the test material and its hydrolysis products 3-methoxy-3-methylbutan-1-ol and acetic acid were verified by GC-FID and HPLC. Mortalities were seen in the 76.9 and 100 mg/L dose levels; all fish at the 100 mg/mL level had died by the 48h timepoint. The 96h LC50 value in Medaka (Oryzias latipes) for the test item was determined to be 73.8 mg/L. The highest concentration (NOEC) showing no mortality after 96h was 59.2 mg/L.