Acute Toxicity of a Recently Identified Phenol-based Synthetic Tsetse Fly Repellent

Abstract

This paper reports on the acute toxicity of a new phenol based synthetic tsetse fly repellent recently identified at the International Centre for Insect Physiology and Ecology (patent No. Ke 00185, 2004). The repellent has been developed for controlling tsetse flies in livestock. The repellent diffuses from specially made dispensers, which are hang around the neck of the animal with the aid of a belt. The aim of the study was to generate toxicity data to support safe use of the product. Mice and rabbits were used to determine acute toxicity and the irritant effects of the repellent, respectively. The 24 hours median lethal dose (LD50) of the repellent was determined in mice after intraperitoneal (i.p.) injection as 40.3mg/kg body weight. The signs of acute toxicity were: decreased locomotor activity, an initial increase followed by a decrease in respiratory rate and an increased depth in respiration, terminal convulsions, coma and death. Death was probably due to respiratory depression. The repellent caused mild dermal irritation characterized by edema and erythema. There was moderate eye irritation affecting the cornea, iris and conjunctiva. The repellent can be classified as being highly toxic with central nervous system (CNS) involvement and a mild skin and eye irritant.