Acute toxicity of 4-nonylphenol to aquatic invertebrates in Taiwan.

Acute toxicity of 4-nonylphenol (NP) was examined in six freshwater species from three phyla - platyhelminthes, arthropoda and mollusca. Values of the 48-hour LC(50) of NP for six species ranged from 20 to 508 ug/L and values of the 96-hour LC(50) for four species ranged from 120 to 457 ug/L. The most sensitive species tested was a water flea, Ceriodaphnia cornuta, with a 48-hour LC(50) of 20 microg/L. The no observed adverse effect level (NOAEL) and lowest observed adverse effect level (LOAEL) values of NP found were in the range of <10 to 400 microg/L and 10 to 450 microg/L after 48 hours of exposure, respectively.