The Relationship of the 96-Hour LC50to the Lethal Threshold Concentration of Hexavalent Chromium, Phenol, and Sodium Pentachlorophenate for Fathead Minnows (Pimephales promelas Rafinesque)

Short-term bioassays were conducted with adult fathead minnows and hexavalent chromium, phenol, and sodium pentachlorophenate at 2 temperatures to determine the relationship of the 96-hour LC50to the lethal threshold concentration. The lethal threshold concentration was less than the 96-hour LC50in 10 of 12 bioassays, was affected by temperature, and was not a constant multiple of the 96-hour LC50for any of the toxicants tested.