Ethylene di(S-thioacetate)

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

see II.2 Analysis of the Test Item Concentrations:
Four samples from the freshly prepared test media of all test concentrations and the control will be taken at the start of the test. For the determination of the stability of the test item under the test conditions and of the maintenance of the test item concentrations during the test period, four samples from the test media of all test concentrations and the control will be collected at the end of the test (after 48 hours) by pouring together the contents of the test beakers of each treatment

Vehicle:

no

Test organisms (species):

Daphnia magna

Details on test organisms:

Species: Daphnia magna (Straus), clone 5. Age at Test Start: From 1.75 to 23.50 hours old Sex: Female Origin: The daphnids introduced in the test were taken from ibacon's in house laboratory culture. Breeding Conditions: The daphnids were bred in the laboratories of ibacon under similar temperature and light conditions as used in the test. The cultivation of the parental daphnids was performed in Elendt M4 medium (see 6.5). The test organisms were not first brood progeny. The daphnids in the stock culture were fed at least on all working days with green algae (Desmodesmus subspicatus) freshly grown in the laboratories of ibacon.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

2.5 mmol/L (= 250 mg/L) as CaCO3

Test temperature:

Water temperature: 20.1 to 20.6 °C

pH:

pH value: 7.8 to 8.0

Dissolved oxygen:

dissolved oxygen concentration: 9.6 to 10.1 mg/L

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

3.94 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

2.07 mg/L

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

4.55 mg/L

Conc. based on:

test mat.

Basis for effect:

mobility

Table 1. Summary of Biological Results
Nominal Concentration [mg test item/L]	% of immobilised daphnids after
	24 hours	48 hours
Control	0	0
0.43	0	0
0.94	0	0
2.07	0	0
4.55	20	75
10	40	100
EC50 [mg test item/L]:  95 % CI [mg test item/L]:	> 10 n.d.	3.94 3.46 - 4.42
EC20 [mg test item/L]: 95 % CI [mg test item/L]:	6.08 3.51 - 8.27	3.10 2.46 - 3.52
EC10 [mg test item/L]: 95 % CI [mg test item/L]:	4.09 1.48 - 5.77	2.64 1.93 - 3.09
NOEC [mg test item/L]:	2.07	2.07
LOEC [mg test item/L]:	4.55	4.55

Values refer to nominal test concentrations
CI: Confidence interval
n.d.: not determinable

Validity criteria fulfilled:

yes

Remarks:

Control Immobilisation Rate: Was 0 % , no daphnid showed signs of disease or stress; thus the validity criterion was met. Dissolved Oxygen Concentration: Was ≥ 9.6 mg O2/L in in all treatment groups at the end of the test; the validity criterion was met.

Conclusions:

The toxic effect of the test item GDMA to Daphnia magna was
assessed in a semi-static concentration-response test. The 48-hour
NOEC was determined to be 2.07 mg test item/L. The 48-hour LOEC
was determined to be 4.55 mg test item/L and the 48-hour EC50 value
was calculated to be 3.94 mg test item/L.
The initial concentrations and the maintenance of the exposure
concentrations during the test were examined in the analytical part.
All reported results refer to nominal concentrations.

Description of key information

The toxic effect of the test item GDMA to Daphnia magna was
assessed in a semi-static concentration-response test. The 48-hour
NOEC was determined to be 2.07 mg test item/L. The 48-hour LOEC
was determined to be 4.55 mg test item/L and the 48-hour EC50 value
was calculated to be 3.94 mg test item/L.
The initial concentrations and the maintenance of the exposure
concentrations during the test were examined in the analytical part.
All reported results refer to nominal concentrations.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

3.94 mg/L