Methyl 3-aminocrotonate

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:

January - March 2000

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Version / remarks:

1992

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Version / remarks:

1992

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

Test item code: LZ937.00
Expiration date: 21 May 2000
Delivery date: 11 October 1999
Test material was stored at ambient temperature in the dark.
Physical state: White crystalline solid
Stoarge conditions: Stored at ambient temperature in the dark

Analytical monitoring:

yes

Vehicle:

no

Details on test solutions:

RANGE FINDING TEST:
Test solutions were prepared by adding a weighed amount of LZ937 (10.00880, 1.0025, 0.0997, 0.01022 g) directly to the appropriate test tank (1000, 100, 10 and 1 ppm respectively). Each test tank contained 10 litres of test media, and the diluent medium was reconstituted freshwater. The tank containing 1000 ppm solution was then ultrasonicated for 5 min to aid solubility.

DEFINITIVE TEST:
The test solutions were prepared by removing a small volume of water from the appropriate test tank. A pre-weighed amount of LZ937 was added and then ultrasonicated for ca 1-2 min to aid dissolution, before being returned to the appropriate tank.

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

Rainbow Trout (Oncorhynchus mykiss) were used for this study and were received from Dennington Trout Farm, on the 19th January 2000. All fish were of the same year class and source. All fish were in good health and free from any apparent malformation. All fish were acclimatised to laboratory conditions for at least 12 days prior to commencement of the study. During holding the fish were fed on a suitable standard fish diet. The fish were not fed for the period 24 h before the commencement of the tests or throughout the duration of the tests.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

average 74 mg CaCO3

Test temperature:

14.3°C - 15.1°C

pH:

7.54 - 8.12

Dissolved oxygen:

> 93.2%

Salinity:

not applicable

Conductivity:

250 - 312 µS

Nominal and measured concentrations:

Range finding: 1000, 100, 10 and 1 p.p.m. with an untreated control (0 p.p.m.).
Definitive test: 100, 50, 25, 12.5, and 6.25 p.p.m. nominal concentrations

Details on test conditions:

Glass tanks (ca 25 litre capacity), covered with perspex lids to minimise dust contamination and evaporation loss, were used as the test vessels. Holding, and all test tanks were filled using reconstituted freshwater suitable for holding fish and produced in the Ecotoxicology facility at lnveresk Research. This was a deviation from the protocol which stated dechlorinated tap water. This deviation is not considered to have affected the validity of the
test. Test tanks were maintained within a temperature-controlled laboratory at approximately 15°C. A light cycle of 16 h light and 8 h dark was in operation throughout the tests. Fluorescent tubes provided artificial daylight illumination.

Reference substance (positive control):

not specified

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

35.4 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Key result

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

25 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

It was observed that 100% mortality occurred in the 1000 and 100 p.p.m. test vessels after 24 h. No further mortality was observed at any other concentration. Effects were observed within 1 h of exposure with fish in the 100 p.p.m. tank beginning to exhibit a loss of equilibrium. After 2 h, all fish in the 100 p.p.m. tank had died and one fish in the 50 p.p.m. tank was starting to exhibit a loss of equilibrium whilst swimming. By 24 h all the fish in the 50 p.p.m. tank had died and the fish in the 25 p.p.m. tank were appearing discoloured and lethargic.Two fish escaped from the tank containing 12.5 p.p.m. of LZ937 and one fish from the tank containing 6.25 p.p.m. LZ937. It is unlikely that this was an effect of the test and these fish were excluded from any calculation of results.

Reported statistics and error estimates:

The LC50 value was estimated based on the geometric mean of the consecutive nominal test concentrations, at which 100 % mortality and no mortality were observed (50 and 25 p.p.m. respectively). This method was applied as conventional probit analysis is not suitable when intermediate values of effect are absent. Similarly the 95 % confidence intervals are conservatively estimated to be the consecutive concentrations at which 0 and 100% effect were observed. The No Observed Effect Concentration (NOEC) based on observation was 25 p.p.m., nominal, under the conditions of the test.

Sublethal observations / clinical signs:

All the tanks were clear and colourless, throughout the duration of the study. No precipitation of test material was observed. This indicates full dispersion or dissolution of the test material in the test medium. All results are based on the nominal concentrations in the absence of analytical results.

Validity criteria fulfilled:

yes

Conclusions:

The 96h LC50 is 35.4 mg/L based on nominal concentrations of LZ937.

Executive summary:

The study was conducted to determine the acute toxicity (LC50) of LZ937 to the fresh water fish Rainbow Trout (Oncorhynchus mykiss). The study was conducted under semi-static conditions for 96 h in accordance

with OECD Guideline 203 for Testing of Chemicals and EC Guideline C 1. Following a preliminary range finding study a definitive test was conducted at 100, 50, 25, 12.5, and 6.25 p.p.m. nominal concentrations of LZ937.

Exposure solutions were replaced after every 24h period. Ten fish were exposed at each concentration in a single replicate vessel. The 96h LC50 is 35.4 mg/L based on nominal concentrations of LZ937.

Development of an analytical method was not possible.

Description of key information

The study was conducted to determine the acute toxicity (LC50) of LZ937 to the fresh water fish Rainbow Trout (Oncorhynchus mykiss). The study was conducted under semi-static conditions for 96 h in accordance

with OECD Guideline 203 for Testing of Chemicals and EC Guideline C 1. Following a preliminary range finding study a definitive test was conducted at 100, 50, 25, 12.5, and 6.25 ppm nominal concentrations of LZ937.

Exposure solutions were replaced after every 24h period. Ten fish were exposed at each concentration in a single replicate vessel.

The 96h LC50 is 35.4 mg/L based on nominal concentrations of LZ937.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

35.4 mg/L