But-2-yne-1,4-diol

Toxicity to aquatic algae and cyanobacteria

Description of key information

72 hour EC50, growth rate, Desdemodesmus subspicatus: 1058 mg/L

72 hour EC20, growth rate, Desdemodesmus subspicatus: 508 mg/L

72 hour EC10, growth rate, Desdemodesmus subspicatus: 346 mg/L

72 hour NOEC, growth rate, Desdemodesmus subspicatus: 125 mg/L

Key value for chemical safety assessment

EC50 for freshwater algae:

1 058 mg/L

EC10 or NOEC for freshwater algae:

125 mg/L

Additional information

The 1,4 -butynediol 72 hour NOEC for growth rate of the freshwater alga (Desdemodesmus subspicatus) provided in a DIN 38412 guideline study is 125 mg/L, the 72 hour EC10 is 346 mg/L, and the 72 hour EC50 is 1058 mg/L (BASF AG 1988). These data are supported by the results of a guideline-equivalent study with Scenedesmus subspicatus which yielded a 72 hour IC50 of >100 mg/L (Tisler, et. al., 2003).