Ethanol, 2-(ethenylthio)-

Short-term toxicity to aquatic invertebrates

Description of key information

In a key static acute toxicity study (Maxxam Analytics, TOX1621, 2016), the effect of the test substance to cause immobilisation to Daphnia magna was determined according to OECD 202 (2004). Based on the nominal concentrations of the test substance the 48-h EC50 was determined to be 50.1 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

50.1 mg/L

Additional information

In a key static acute toxicity study (Maxxam Analytics, TOX1621, 2016), the effect of the test substance to cause immobilisation to Daphnia magna was determined by using a static renewal aquatic exposure method based on the guidance of OECD 202 Daphnia sp. Acute Immobilisation Test (2004). The effect was measured by determining the number of Daphnia immobilised during a 48-hr exposure period with one water renewal (24 hours) to a range of nominal concentrations of 6.25, 12.5, 25, 50 and 100 mg test Item/L, along with a laboratory (negative) control (0 mg/L). Since the test item has a water solubility of 105.5 g/L at 20°C, a stock solution was prepared at 100 mg test item/L and test solutions were prepared as dilutions of this stock solution. The measured concentrations of the test substance were determined to be 10.0, 22.0, 44.5, and 93.0 mg/L. The measured concentrations of the test item were within 80% to 120% (80% to 93%) of the nominal concentration. A reference item test using zinc sulphate heptahydrate (ZnSO4•7H2O) was conducted as a separate study to assess the relative sensitivity of the test organisms and the precision of the data produced by the laboratory. After 48 hours, the LC50 of the reference substance was determined to be 0.35 mg/L. The results with reference substance was determined valid. The test met validity criteria with 0% of the control organisms showing immobilisation, signs of disease, stress, or unusual behaviour, and the minimum dissolved oxygen concentration in the test solutions at the end of the test was >3 mg O2/L (8.9 – 9.0 mg O2/L). The water quality measurements (e.g., temperature, pH) were also within the tolerance limits of the test organism. The test endpoint was based on the nominal concentration of the test item since the measured concentrations of the test item were within 80% to 120% (80% to 93%) of the nominal concentration. Based on the nominal concentrations of the test substance the 48-h EC50 was determined to be 50.1 mg/L.