Butyl 3-hydroxybutyrate

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:

12 to 14 June 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 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

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 preliminary range-finding results

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):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Source: Smithers Viscient
- Age at study initiation (mean and range, SD): less than 24 hours
- Feeding during test: no
- Food type: suspension of Chlorella vulgaris
- Amount: 1 mg organic carbon/L of culture water and YCT
- Frequency: every other working day

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test temperature:

20.4 to 21.6°C

pH:

7.38 to 8.02

Dissolved oxygen:

5.99 to 7.78

Salinity:

not applicable

Nominal and measured concentrations:

range finding nonmial concentrations were 0.1, 1.0, 10, and 100 mg/L; definitive nominal concentration was 100 mg/L reported as 95.8 mg/L measured or 96.3%.

Details on test conditions:

TEST SYSTEM
- Test vessel: plastic
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: 25 ml
- Aeration: none
- Renewal rate of test solution (frequency/flow rate): 24 hour renewal
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Elendt M4 media:
- Range finding study yes
- Test concentrations: 0.1, 1.0, 10, 100
- Results used to determine the conditions for the definitive study: yes

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

not specified

Basis for effect:

mortality

Details on results:

- Behavioural abnormalities: 5 daphnids in 100 mg/L were trapped in the meniscus at 24 hours with 1 daphnid moving slowly. At 48 hours, 6 organsims were trapped in the meniscus and 1 was moving slowly.

- Mortality of control: none
- Other adverse effects control: 2 organisms were trapped in the meniscus at 24 hours with no signs of abnormal behaviour at 48 hours
- Effect concentrations exceeding solubility of substance in test medium: no

Results with reference substance (positive control):

not applicable

Reported statistics and error estimates:

none

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 202 and GLP and was therefore deemed valid and reliable. The 48-hr EC50 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 cladoceran, Daphnia magna in a 48 hour exposure following OECD 202. 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 no mortality reported after 48 hours of exposure, so a limit test at 100 mg/L was conducted following guideline recommendations. The 48-hr EC50 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 202 and GLP and was therefore deemed valid and reliable.  The 48-hr EC50 value was > 100 mg/L (nominal).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L