Methyl 3-mercaptopropionate

Short-term toxicity to fish

Administrative data

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2005-07-18 to 2005-12-01

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP study conducted according to OECD Guideline 203 "Fish, Acute Toxicity Test" and EU Commission Directive 92/69/EEC, Part C.1 "Acute Toxicity for Fish".

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2005

Report date:

2005

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Deviations:

no

Principles of method if other than guideline:

N/A

GLP compliance:

yes (incl. QA statement)

Remarks:

The Swiss GLP Monitoring Authorities, Bern, Switzerland

Test material

Test material information

Constituent 1

Reference substance name:

Methyl 3-mercaptopropionate

EC Number:

220-912-4

EC Name:

Methyl 3-mercaptopropionate

Cas Number:

2935-90-2

Molecular formula:

C4H8O2S

IUPAC Name:

methyl 3-sulfanylpropanoate

Details on test material:

- Name of test material (as cited in study report): 3-mercaptopropanoic acid methyl ester (MMP)
- Molecular formula (if other than submission substance): N/A
- Molecular weight (if other than submission substance): N/A
- Smiles notation (if other than submission substance): N/A
- InChl (if other than submission substance): N/A
- Structural formula attached as image file (if other than submission substance): N/A
- Substance type: active
- Physical state: liquid

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
N/A

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

N/A

Test solutions

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: 16.1 g test substance was dissolved in 350 mL DMF, using intense stirring for 10 minutes. Dilutions were made with DMF to lower concentrations. These dosing concentrations were mixed continuously by magnetic stirrer, and dispensed via digital dispenser into mixing vessels to be stirred with tap water. This mixture then flowed out into the test aquaria. Each concentration had a separate dispenser unit.
- Eluate: Local tap water
- Controls: Tap water control and vehicle control
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): The solvent N,N-Dimethylformamide (DMF) was used as vehicle for the dosage of the test item with limited water solubility. This solvent was chosen for its solubility properties and its relative non-toxicity to fish.
- Concentration of vehicle in test medium (stock solution and final test solution(s) including control(s)): 100 uL/L
- Evidence of undissolved material (e.g. precipitate, surface film, etc): no

Test organisms

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: Rainbow trout
- Strain: N/A
- Source: P. Hohler trout breeding station Zeiningen, Switzerland
- Age at study initiation (mean and range, SD): N/A
- Length at study initiation (length definition, mean, range and SD): 5.4 ± 0.15 cm (average of 10 fish)
- Weight at study initiation (mean and range, SD): 1.6 ± 0.15 g (average of 10 fish)
- Method of breeding: purchased from breeder
- Feeding during test
- Food type: N/A
- Amount: N/A
- Frequency: Not fed during test.


ACCLIMATION
- Acclimation period: The fish were held in the laboratories for 12 days without any medication. Prior to the test start, they were acclimated for one week to the test water and temperature.
- Acclimation conditions (same as test or not): same as test
- Type and amount of food: Commercial fish diet-HOKOVIT 502, 1.2 mm; H.U. Hofman AG, Butzburg, Switzerland
- Feeding frequency: Daily during holding and acclimation, until one day prior to testing
- Health during acclimation (any mortality observed): No mortality and all fish appeared healthy.


QUARANTINE (wild caught)
- Duration: N/A
- Health/mortality: N/A

Study design

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

N/A

Test conditions

Hardness:

198 mg/L CaCO3

Test temperature:

14 deg. C

pH:

7.4-7.9

Dissolved oxygen:

>=8.5 mg/L

Salinity:

N/A

Nominal and measured concentrations:

0.22, 0.46, 1.0, 2.2 and 4.6 mg/L, and in parallel a control and a solvent control (100 uL/L DMF).
The mean measured test item concentrations (calculated as the average overall measurements per test concentration) ranged from 57 to 119% of the nominal values. All reported biological results are related to the mean measured concentrations of the test item.

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: glass aquaria, 48 L test solution
- Aeration: flow through
- Type of flow-through (e.g. peristaltic or proportional diluter): proportional diluter
- Renewal rate of test solution (frequency/flow rate): sixfold theoretical volume exchange per day
- 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): 1
- Biomass loading rate: 0.23 g fish wet weight per liter


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Local tap water (non-chlorinated well water of drinkinig water quality), reduced for total hardness by ion
exchange.
- Total organic carbon: N/A
- Particulate matter: N/A
- Metals: BDL
- Pesticides: BDL
- Chlorine: N/A
- Alkalinity: N/A
- Ca/mg ratio: N/A
- Conductivity: N/A
- Culture medium different from test medium: N/A
- Intervals of water quality measurement: N/A


OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 hours light and 8 hours dark
- Light intensity: 50-500 Lux ( with a 30-minute transition period).



EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : The test fish were observed after approximately 3, 24, 48, 72 and 96 hours test duration for mortality and visible abnormalities.


TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2
- Justification for using less concentrations than requested by guideline: N/A
- Range finding study
- Test concentrations: Range finding study conducted, concentrations not stated in study report.
- Results used to determine the conditions for the definitive study: yes

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

3 h

Dose descriptor:

LC50

Effect conc.:

> 2.6 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Effect concentrations 2

Duration:

24 h

Dose descriptor:

LC50

Effect conc.:

2.5 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% CI 2.1-2.9 mg/L

Effect concentrations 3

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

1.8 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% CI 1.1-3.0 mg/L

Effect concentrations 4

Duration:

72 h

Dose descriptor:

LC50

Effect conc.:

1.7 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% CI 1.2-2.4 mg/L

Effect concentrations 5

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

1.7 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% CI 1.2-2.4 mg/L

Effect concentrations 6

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

0.4 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

behaviour

Effect concentrations 7

Duration:

96 h

Dose descriptor:

LC0

Effect conc.:

0.4 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Effect concentrations 8

Duration:

96 h

Dose descriptor:

LC100

Effect conc.:

2.1 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Effect concentrations 9

Duration:

96 h

Dose descriptor:

LOEC

Effect conc.:

1.2 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

behaviour

Details on results:

- Behavioural abnormalities: Tumbling during swimming, Strong ventilation, Fish mainly at the bottom of the aquarium, Fish mainly at the water surface
- Observations on body length and weight: N/A
- Other biological observations: N/A
- Mortality of control: none
- Other adverse effects control: N/A
- Abnormal responses: N/A
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: N/A
- Effect concentrations exceeding solubility of substance in test medium: N/A

Results with reference substance (positive control):

N/A

Reported statistics and error estimates:

The LC50 and the 95% confidence interval were calculated by Moving Average Interpolation. The NOEC, LOEC, LC0 and LC100 were determined directly from the raw data.

Any other information on results incl. tables

Sublethal observations / clinical signs:

Table 1. Nominal vs. Measured Test Concentrations

Nominal Conc. (mg/L)	Mean Measured Conc. (mg/L)	% of Nominal
0.22	-	-
0.46	0.40	86
1.0	1.2	119
2.2	2.1	94
4.6	2.6	57

-      Not analyzed, below NOEC

 

 

Table 2. Mortality and Behavioral Observations (# abnormal and dead/#dead, type of abnormality)

Nominal Conc. (mg/L)	3h	24h	48h	72h	96h
Control	0/0	0/0	1/1	1/1	1/1
Solvent	0/0	0/0	0/0	0/0	0/0
0.22	0/0	0/0	1/1	1/1	1/1
0.46	0/0	0/0	0/0	0/0	0/0
1.0	0/0	0/0	3/1, TS	3/1, TS	3/1, TS
2.2	0/0	2/1, TS	7/5, TS,SV	7/7	- -
4.6	3/0, BO,OB	7/7	- -	- -	- -

TS: Tumbling during swimming; BO: Fish mainly on bottom; OB: Fish mainly at surface

 SV:Strong Ventilation; --: All fish dead.

 

Table 3. Dissolved oxygen Concentration

Nominal Conc. (mg/L)	3h	24h	48h	72h	96h
Control	9.5	9.6	8.5	9.2	9.4
Solvent	9.4	9.6	8.6	9.1	9.0
0.22	9.6	9.4	8.6	9.3	9.1
0.46	9.6	9.6	8.6	9.2	8.8
1.0	9.6	9.6	8.6	9.4	9.0
2.2	9.5	9.7	8.6	9.6	-
4.6	9.4	9.5	-	-	-

-      Not measured since all fish were dead.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The 96h LC50 of the test substance to rainbow trout was found to be 1.7 mg/L, with a 95% confidence interval of 1.2-2.4 mg/L. The 96h NOEC was found to be 0.40 mg/L.

Executive summary:

N/A