Ethyl L-threoninate

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:

2007.09.03 - 2007.09.07

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:

ISO 7346-1 (Determination of the Acute Lethal Toxicity of Substances to a Freshwater Fish [Brachydanio rerio Hamilton-Buchanan (Teleostei, Cyprinidae)] - Part 2: Semi-static method)

Deviations:

no

Principles of method if other than guideline:

ISO International Standard 7346 " Water quality-
determination of the acute lethal toxicity of substances to
a freshwater fish (Brachydanio rerio Hamilton-Buchanan
(Teleostei, Cyprinidae) part 2 - Semi-Static Method.

GLP compliance:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch number of test material: 0706H016

Details on properties of test surrogate or analogue material (migrated information):
PHYSICO-CHEMICAL PROPERTIES
- Melting point: 50-55°C
- Boiling point: 180.7-202.1°C
- Water solubility (under test conditions): > 4,000 g/L (20ºC)
OTHER PROPERTIES (if relevant for this endpoint)
- Results of test for ready biodegradability: 97+/-3% of the ThOD after 28 days

Analytical monitoring:

yes

Details on sampling:

- Concentrations: control (0mg/L) and highest test concentration (2,000mg/L)
- Sampling method: The actual test concentrations were verified by a chemical analysis of the Total Organic Carbon (TOC) content in the test solutions. At the initiation of the test and before and after renewal of the test solutions, 2 × 10-mL subsamples of each test solution were collected in Nunc Immuno Minisorp Tubes for chemical analysis of TOC.
- Sample storage conditions before analysis: The samples were stored in glass bottles at -18°C until analysis.

Vehicle:

no

Details on test solutions:

Identity and concentration of auxiliary solvent for dispersal: The test substance was dissolved in test medium. The test
medium was prepared from Millipore water according to ISO 7346-2 standard, part 2: Semistatic method.

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: Danio rerio
- Strain: no data
- Source:Credo Fish, Nørresundby, Denmark, and purchased from Hørsholm Dyrehandel, Hørsholm, Denmark
- Age at study initiation (mean and range, SD): juvenile
- Length at study initiation (length definition, mean, range and SD): 2.5 ± 0.5
- Weight at study initiation (mean and range, SD): no data
- Feeding during test: no feeding
- Food type: NA
- Amount:10 fish/ concentration
- Frequency: NA

ACCLIMATION
no data

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

None

Hardness:

CA 250 mg CaCO3/L

Test temperature:

22.7 ± 0.5°C (measured)

pH:

7.6-7.8 (measured)

Dissolved oxygen:

92-100% (measured)

Salinity:

NA

Nominal and measured concentrations:

Nominal concentration Sampling time Theoretical organic carbon content Actually measured organic carbon content (mg TOC/L)
Control 0 hours new 0 <2*
Control 24 hours old 0 <2*
Control 72 hours new 0 <2*
Control 96 hours old 0 <2*
2,000 mg/L 0 hours new 979 919
2,000 mg/L 24 hours old 979 711
2,000 mg/L 72 hours new 979 1,108
2,000 mg/L 96 hours old 979 1,102

Details on test conditions:

TEST SYSTEM
- Test vessel:Glass aquaria 4.5 L
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: 4,5L aquaria filled 3,5L
- Aeration:none
- Renewal rate of test solution (frequency/flow rate): every 24h
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- No. of vessels per vehicle control (replicates): NA
- Biomass loading rate:<1g/L


OTHER TEST CONDITIONS
- Adjustment of pH: no data
- Photoperiod:14:10 light:dark
- Light intensity: no data

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : mortality

TEST CONCENTRATIONS
- Spacing factor for test concentrations:2
- Range finding study: No
- Test concentrations: 0, 100, 200, 500, 1000 mg/L
- Results used to determine the conditions for the definitive study: not stated

Reference substance (positive control):

yes

Remarks:

potassium dichromate (K2Cr2O7)

Duration:

24 h

Dose descriptor:

LC50

Effect conc.:

> 2 000 mg/L

Nominal / measured:

nominal

Conc. based on:

other:

Basis for effect:

mortality (fish)

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

> 2 000 mg/L

Nominal / measured:

nominal

Conc. based on:

other:

Basis for effect:

mortality (fish)

Duration:

72 h

Dose descriptor:

LC50

Effect conc.:

> 2 000 mg/L

Nominal / measured:

nominal

Conc. based on:

other:

Basis for effect:

mortality (fish)

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 2 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Behavioural abnormalities: none
- Observations on body length and weight: Length at the end of the test (control group) 22.5 mm (SD 2.68). Weight at the end of the test (control group): 0.2 g(SD=0.07)
- Other biological observations: Records were kept of visible abnormalities, i.e. loss of equilibrium, changes in swimming behaviour, respiratory
function and pigmentation. No effects observed.
- Mortality of control: The mortality in the controls did not exceed 10% at the end of the test period
- Other adverse effects control: none
- Abnormal responses: none
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: none stated
- Effect concentrations exceeding solubility of substance in test medium: No

Results with reference substance (positive control):

- Results with reference substance valid? yes
- LC50: 185mg/L

Reported statistics and error estimates:

Probit analysis. Version 2.3, 1990.03.20

Sublethal observations / clinical signs:

no

Validity criteria fulfilled:

yes

Conclusions:

No mortality was observed in any of the exposure concentrations. Therefore the results indicated LC10 and LC50 as > 2,000 mg/L.

Executive summary:

L-TEE was tested according to the OECD No. 203 which is further specified in the ISO International Standard 7346-2 Part 2.

The following nominal concentrations were applied and renewed every 24 hours: 0 (control); 100; 200; 500; 1,000 and 2,000 mg/L.

The number of dead fish was recorded after 2; 24; 48; 72 and 96 hours.

The actual test concentrations were verified by analysis of the Total Organic Carbon (TOC) content.

• The TOC analyses performed on subsamples from the control and the highest test

concentrations at the initiation and termination of the test, respectively, showed a

recovery of the test substance > 80%. Therefore the obtained results are based on the nominal test concentrations.

• No mortality or behavioural effects were observed in concentrations ≤ 2,000 mg/L.

Based on the obtained results, the LC10 and LC50 are thus given as > 2,000 mg/L.

Description of key information

No mortality was observed in any of the exposure concentrations. Therefore the results indicated LC10 and LC50 as > 2,000 mg/L.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

2 000 mg/L