Ethylene bis(3-mercaptopropionate)

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:

2015

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:

17 July 1992

Deviations:

not specified

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Samples were taken at 0, 96 h and 24 h, 48 h, 72 h (before and after test solution renewal)

Vehicle:

yes

Remarks:

test water

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: zebra fish
- Source: Guangzhou Yangshi breeding farm
- Length at study initiation (length definition, mean, range and SD): 2.0-4.0 cm

ACCLIMATION
- Acclimation period: 23 days
- Acclimation conditions (same as test or not): same
- Type and amount of food during acclimation: 3 times per day until 24 h before test
- Health during acclimation (any mortality observed): 0.9% mortality during 7 days preceding the test

FEEDING DURING TEST : no

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

111 mg CaCO3/L

Test temperature:

21.2 - 22.9 °C

pH:

7.41 - 7.90

Dissolved oxygen:

min. 60% of air saturation value

Nominal and measured concentrations:

Nominal: 0.26, 0.36, 0.51, 0.71, 1.0 mg/L
Measured: 0.0492, 0.0580, 0.0677, 0.0819, 0.0936 mg/L (geometric means)

Details on test conditions:

14 h light / 10 h darkness
Mortality and visible abnormalities were recorded at 3, 24, 48, 72, and 96 h after the start of the test

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

0.42 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

59.4 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC100

Effect conc.:

81.9 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

< 0.049 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Behavioural abnormalities: spasmodic swimming, reduced activity, overturn and loss of equlibrium were observed at all dose levels
- Observations on body length and weight: no effects
- Other biological observations: none
- Mortality of control: no effects
- Other adverse effects control: no effects
- Abnormal responses:no effects
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: no effects
- Effect concentrations exceeding solubility of substance in test medium: no

Results with reference substance (positive control):

K2Cr2O7: 24-h LC50 = 282 mg/L, 95% CI: 251 - 318 mg/L (LC50 validity range: 200 - 400 mg/L)

Reported statistics and error estimates:

96-h LC50 = 0.0594 mg/L, 95% CI: 0.0568 - 0.0621 mg/L

Sublethal observations / clinical signs:

Nominal conc. (mg/L)	No. of fish in group	Cumulative mortality (%) after (h)
		3	24	48	72	96
0	21	0	0	0	0	0
0.26	21	0	0	0	4.8	4.8
0.36	21	4.8	4.8	29	38	37
0.51	21	38	67	90	90	90
0.71	21	81	100	100	100	100
1.0	21	100	100	100	100	100

 

Validity criteria fulfilled:

yes

Remarks:

mortality of controls < 10% (0%), dissolved oxygen >60% (80-100%), the measured concetrations (geomean) are used since these were outside the 80-120% window

Conclusions:

96 hLC50 = 0.42 mg/L, nominal

Executive summary:

The short-term toxicity of GDMP to zebra fish (Brachydanio rerio) was assessed in a study according to OECD TG 203. The fish were exposed to five test concentrations of 0.26, 0.36, 0.51, 0.71 and 1.0 mg/L (nominal) of the test item under semi-static conditions (renewal every 24 h).

The cumulative mortality was 0% at the end of the test. The cumulative mortality in teh 0.26, 0.36, 0.51, 0.71 and 1.0 mg/Lgroups was 4.8, 38, 90, 100 and 100%, respectively.No abnormal sublethal responsed were observed in the control. Behavioural abnormalities including spasmodic swimming, reduced activity, overturn and loss of equlibrium were observed at all concentrations levels.

Under the conditions of this test, the 96 h LC50 to Danio rerio was 0.0594 mg/L (mean, meas.).

Since measured values don't represent the real environmental conditions because the test substance is rapidly oxidized by the oxygen content in the aqueous phase.

As the transformation products are less toxic than the parent substances (no free –SH groups) regulatory endpoints calculated on the basis of nominal concentrations represent a realistic worst case approach.  Moreover, for thiochemicals nominal concentrations represent the real environmental conditions, because the test substance is rapidly oxidized by the oxygen content in the aqueous phase.  The effect values therefore reflect the toxicity of the system – in the sense of the UVCB approach – rather than the toxicity of the original chemical substance. Under these conditions it is more meaningful to assess their toxicities on the basis of nominal concentrations instead of measured concentrations during exposure. This may better correspond to the situation under environmental conditions as recommended for multi-component-substances (OECD23).

The 96 h LC50 based on nominal concentrations was determined to be 0.42 mg/L.

 

 

Description of key information

The 96 h LC50 based on nominal concentrations was determined to be 0.42 mg/L.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

LC50

Effect concentration:

0.42 mg/L

Additional information

The short-term toxicity of GDMP to zebra fish (Brachydanio rerio) was assessed in a study according to OECD TG 203. The fish were exposed to five test concentrations of 0.26, 0.36, 0.51, 0.71 and 1.0 mg/L (nominal) of the test item under semi-static conditions (renewal every 24 h).

The cumulative mortality was 0% at the end of the test. The cumulative mortality in teh 0.26, 0.36, 0.51, 0.71 and 1.0 mg/Lgroups was 4.8, 38, 90, 100 and 100%, respectively.No abnormal sublethal responsed were observed in the control. Behavioural abnormalities including spasmodic swimming, reduced activity, overturn and loss of equlibrium were observed at all concentrations levels.

Under the conditions of this test, the 96 h LC50 to Danio rerio was 0.0594 mg/L (mean, meas.).

Since measured values don't represent the real environmental conditions because the test substance is rapidly oxidized by the oxygen content in the aqueous phase.

As the transformation products are less toxic than the parent substances (no free –SH groups) regulatory endpoints calculated on the basis of nominal concentrations represent a realistic worst case approach.  Moreover, for thiochemicals nominal concentrations represent the real environmental conditions, because the test substance is rapidly oxidized by the oxygen content in the aqueous phase.  The effect values therefore reflect the toxicity of the system – in the sense of the UVCB approach – rather than the toxicity of the original chemical substance. Under these conditions it is more meaningful to assess their toxicities on the basis of nominal concentrations instead of measured concentrations during exposure. This may better correspond to the situation under environmental conditions as recommended for multi-component-substances (OECD23).

The 96 h LC50 based on nominal concentrations was determined to be 0.42 mg/L.