Immunotoxicological investigation of SCMF, a new pyrethroid pesticide in mice.

The toxicity of a new pyrethroid pesticide Supercypermethrin Forte (SCMF) was studied in male CFLP mice using classic toxicological (body weight, organ weights) and haematological (white blood cell count, haematocrit, nucleated cell content of femoral bone marrow) methods and immune function tests (PFC assay, DTH reaction). Four weeks of oral treatment in a 5 days per week system at doses of 1/10, 1/20, or 1/40 x LD50 did not cause evaluable changes in the measured parameters. When single calculated LD20, LD10, or LD5 doses of SCMF were administered on different days before termination to different groups of mice the two higher doses caused a time- and dose-dependent decrease in the splenic PCF number. Apart from some temporary toxic signs and an increase of haematocrit at the top dose the other examined parameters did not show evaluable changes. Under these experimental conditions toxic changes appeared only at the high dose range and, of those applied, the PFC assay proved to be the most sensitive method for detecting the toxicity of SCMF.