Butyl 3-hydroxybutyrate

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:

24 - 28 June and 01 - 05 July 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was conducted under the appropriate guideline following GLP methodology.

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

yes

Remarks:

The linearity, LOD/LOQ and analytical precision assessment were conducted as part of a separate study.

Principles of method if other than guideline:

not applicable

GLP compliance:

yes

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
not applicable

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 100 mg/L (Limit Test) based on the results of a preliminary range-finding test

Vehicle:

no

Details on test solutions:

Test concentration were prepared by addition of the required amount of n-Butyl-3-hydroxybutyrate directly to the dilution water to give the required concentration of 100 mg/L.

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name:Rainbow trout
- Source: Bibury Trout Farm, Bibury, Cirencester, Gloucestershire, GL7 5NL, UK
- Age at study initiation (mean and range, SD):
- Length at study initiation (length definition, mean, range and SD): 59.1 mm (range 57 to 60 mm) measured from the stock at test termination
- Weight at study initiation (mean and range, SD): 2.04 g (range 1.83 to 2.21 g) measured from the stock at test termination
- Feeding during test
- Food type: proprietary trout food
- Amount:1 -2 % of body weight per day
- Frequency: daily until 24 hours before study initiation

ACCLIMATION
- Acclimation period: 17 May 2013 to 01 July 2013
- Acclimation conditions (same as test or not): same as test conditons, temperature 15.0 to 16.0°C, DO2 >92% ASV and 16:8 photoperiod

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Post exposure observation period:

no abnormal behavior noted.

Hardness:

284 mg CaCO3/L

Test temperature:

The test vessels were maintained at 15.5 to 16.0°C

pH:

Test pH values in the control and 100 mg/L solutions from fresh and aged solutions franged from 8.03 to 8.53.

Dissolved oxygen:

Dissolved oxygen values ranged from 83 to 96% ASV.

Salinity:

NA

Nominal and measured concentrations:

The nominal test concentration was 100 mg/L with the mean measured concentration after 96-hr reported as 95.7 mg/L with a mean percentage recovery of 96.2%.

Details on test conditions:

TEST SYSTEM
- Test vessel: 20 L glass aquaria
- Type (delete if not applicable): open
- Aeration: no
- Renewal rate of test solution (frequency/flow rate): every 24 hours
- No. of organisms per vessel: 7
- No. of vessels per concentration (replicates):1
- No. of vessels per control (replicates):1
- No. of vessels per vehicle control (replicates): not applicable
- Biomass loading rate: not included

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: dechlorinated mains water

- Photoperiod: 16 hours light/ 8 hours dark
- Light intensity:

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :

TEST CONCENTRATIONS
- - Range finding study: yes
- Test concentrations: 0.1, 1.0, 10 and 100 mg/L
- Results used to determine the conditions for the definitive study: yes

Reference substance (positive control):

not specified

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

not specified

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

not specified

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

not specified

Basis for effect:

other: visible sublethal effects

Details on results:

- Behavioural abnormalities: none
- Observations on body length and weight:
- Other biological observations:
- Mortality of control: none
- Other adverse effects control:none
- Abnormal responses:none
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: no
- Effect concentrations exceeding solubility of substance in test medium: no

Results with reference substance (positive control):

NA

Reported statistics and error estimates:

ToxCalc(TM) Version 5.0

Validity criteria fulfilled:

yes

Conclusions:

The study was conducted as a Limit Test based upon preliminary range-finding results with no reported mortaliy in the 100 mg/L concentration. The study followed OECD 203 and GLP and was therefore deemed valid and reliable. The 96-hr LC50 value was > 100 mg/L (nominal).

Executive summary:

A study was conducted to determine the the acute toxicity of n-Butyl-2 -hydroxybutyrate to the rainbow trout (Oncorhynchus mykiss) in a 96 hour exposure following OECD 203. Analytical measurement of the exposure solutions showed mean measured concentrations that were 80 to 120% of nominal therefore all concentrations are reported as nominal concentrations. A preliminary range-finding study with concentrations of 0.1, 1.0, 10 and 100 mg/L had only 1 mortality reported at the high dose after 24 hours, so a limit test at 100 mg/L was conducted following guideline recommendations. The 96 -hr LC50 value was estimated to be >100 mg/L. The highest no observed effect concentration (NOEC) for both mortality and visible sub-lethal effects after 96 hours was 100 mg/L.

Description of key information

The study was conducted as a Limit Test based upon preliminary range-finding results with no reported mortaliy in the 100 mg/L concentration.  The study followed OECD 203 and GLP and was therefore deemed valid and reliable. The 96-hr LC50 value was > 100 mg/L (nominal).

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

100 mg/L