Evaluation of acute toxicity of phenol and its chloro- and nitro-derivatives to certain teleosts

Acute toxicity bioassays were conducted to evaluate the comparative toxicity of phenol (an aromatic hydrocarbon) pentachlorophenol (chloro-derivative of phenol) and dinitrophenol (nitro-derivative of phenol) for determining the LC50 and acute toxicity range for 24, 48, 72 and 96h, against the test fishes Notopterus notopterus, Colisa fasciatus and Saccobranchus fossilis. Relative susceptibility of fish, safe concentrations, heterogeneity factors and fiducial limits (95 %) were calculated using 96 h LC₅₀ values. Regression equations and slope functions (s) were calculated for each time interval. On the basis of relative susceptibility for phenol, Notopterus notopterus was found to be more susceptible as compared to Saccobranchus fossilis and the susceptibility of Colisa fasciatus lies in between the two. In case of pentachlorophenol and dinitrophenol, susceptibility lies in the increasing order from Colisa fasciatus, Saccobranchus fossilis to Notopterus notopterus.