4-hydroxy-4-methylpentan-2-one

Toxicity to aquatic algae and cyanobacteria

Description of key information

An acute toxicity study was performed to assess the toxicity of DAA to freshwater algae species Pseudokirchnerella subcapitata (Mitsubishi Chemical Safety Institute Ltd., 1997). The study was conducted under GLP and according to OECD Test Guideline 201. One nominal concentration, 1000 mg/L, was tested as a the limit test. pH at the start of exposure was 7.9, pH at the end of exposure was 7.8 and the temperature was23 ±2 °C. Based on biomass, the 72 -hr EC50 was greater than 1000 mg/L and the 72 -hr NOEC was 1000 mg/L. Based on growth rate, the (24 -72)-hr EC50 was greater than 1000 mg/L and the (24 -72)-hr NOEC was 1000 mg/L. 

Three toxicity studies were conducted to assess the acute toxicity of DAA in Scenedesmus quadricauda and Microcystis aeruginosa (Bringmann and Kühn, 1977, 1978ab). The studies did not follow GLP and were not conducted according to any set guidelines. The studies were all rated ‘2’ for reliability under Klimisch standards. 

Bringmann and Kühn (1977, 1978a) evaluated the inhibition of cell proliferation in Scenedesmus quadricauda by DAA in a static freshwater system. Oxygen concentration was not measured. Growth was measured as relative turbidity at the beginning and at the end of the study. The authors reported that the toxicity threshold (8 d) of DAA in the S. quadricauda growth inhibition test is: 3000 mg/L in both study reports. 

Bringmann and Kühn (1978b) also evaluated the inhibition of cell proliferation in Microcystis aeruginosa by DAA in a static freshwater system. Growth inhibition was measured as relative turbidity at the end of the study (8 d) versus substance concentration. The authors reported that the toxicity threshold (8 d) of DAA in the M. aeruginosa growth inhibition test is: 530 mg/L.