2,4-dithiapentane

Endpoint summary

Description of key information

Acute aquatic toxicity
Daphnia was the most sensitive species in acute toxicity tests with the test substance, according to OECD guideline, resulting in a 48 -hour EC50 37.2 mg/L. Based on acute aquatic toxicity results obtained, the substance has not to be classified according to Regulation (EC) No 1272/2008 (CLP).

Chronic toxicity
The test substance was tested in an aquatic toxicity test with algae, according to OECD guideline 201. The 72 -hour EC50 and EC10 for growth rate was > 100 and 32.8 mg/L, and 72 -hour NOEC 7.23 mg/L. Thus, the substance has not to be classified according to Regulation (EC) No 1272/2008 (CLP).

Based on acute aquatic toxicity results obtained, the substance has not to be classified as environmental acute toxic according to Regulation (EC) No 1272/2008 (CLP). However, as only one chronic endpoint (algae) is available and the substance is not readily biodegradable the acute endpoint from Daphnia is used for chronic classification. The substance has to be classified as environmental chronic toxic cat. 3 (H412) according to Regulation (EC) No 1272/2008 (CLP).

Additional information

Short-term toxicity to invertebrates

In the acute immobilisation test (reference 6.1.3-1) with Daphnia magna (STRAUS), the effects of the test item were determined according to OECD Guideline for testing of chemicals, Guideline No. 202, adopted 13th April 2004. The study was conducted in a static system over a period of 48 hours with nominal concentrations of 6.25, 12.5, 25, 50 and 100 mg/L (corresponding to geometric measured concentrations of 4.2, 7.9, 16.4, 34.0 and 67.8 mg/L). The validity criteria of the test guideline were fulfilled. The EC50 value (48 hours) was determined to be 37.2 mg/L (mean measured).

Toxicity to aquatic algae

The effect of the test item on the growth of a unicellular green algal species Raphidocelis subcapitata was determined according to OECD 201, Regulation (EC) No. 226/2016 Method C.3 and EPA OPPTS 850.5400 and under GLP (reference 6.1.5-1). The study was conducted under static conditions with an initial cell density of 1x10^4 cells/mL for a period of 72 hours. A stock solution of 100 mg/L was freshly prepared with OECD Medium and shaken overnight and the non-dissolved test material was separated by filtration. Five concentrations were tested in a geometrical series with a dilution factor of 3.2: 0.95, 3.05, 9.77, 31.3 and 100 mg/L ((corresponding to 0.63, 2.01, 7.23, 23.5 and 72.3 mg/L (calculated geometric mean concentrations)).The EC50 values for inhibition of growth rate (ErC50) was > 100 mg/L and for inhibition of yield (EyC50) 91.6 mg/L. The EC10 value was determined to be 32.8 mg/L based on growth rate (ErC10) and 2.34 mg/L based on yield (EyC10).