The purpose of this project was to determine the combustion efficiency of plastics when burned in several types of laboratory incinerators. These laboratory units were designed to simulate the primary flame zones of municipal incinerators. The parameters of efficiency considered were: Percent of material consumed, the chemical 'cleanliness' of the gaseous effluent, the rate of production of flyash, and the more obvious environmental effects of the gaseous effluent, flyash, and residue-ash. Several pure resins were burned individually in several laboratory incinerators. Also, several mixtures of plastics and a garbage recipe were burned. Results are presented here from analyses of the effluent along with the effects of each effluent on rats and plants for 1- to 8-hour exposures.