TOXIC COMBUSTION BY-PRODUCTS FROM THE INCINERATION OF CHLORINATED HYDROCARBONS AND PLASTICS

Polyvinylidene chloride and polyvinyl chloride were pyrolyzed in a the rmal gravimetric analyzer and by-products were collected for chemical analysis and bioassay. Trichloroethylene was also burned in a laminar diffusion flame of methane with varying concentrations of the chlorina ted compound. Soot particulates collected on filters and post-flame ga ses collected on sorbent tubes were extracted and analyzed using gas c hromatography-mass spectrometry. Extracts were evaluated for potential toxicity using an in vitro hyperkeratinization bioassay that is sensi tive to 2,3,7,8-tetrachlorodibenzo-p-dioxin. Chemical analyses identif ied polycyclic aromatic hydrocarbons and chlorinated PAHs as the major pyrolysis products. Products generated from the pyrolysis of both pol ymers yielded definite positive bioassay responses. Most of the produc ts obtained from the trichloroethylene flame were associated with soot particles emitted from the flame. A series of chlorinated aromatic co mpounds, including hexachlorocyclopentadiene and chlorinated benzenes, polycyclic aromatics, and fulvalenes were identified as major product s. Dichloromethane extracts of the soots elicited a positive bioassay response.