Many components of typical wastes produce a variety of toxic or potentially toxic compounds when subjected to combustion. Plastics particularly can yield CO, CO/sub 2/, HCL, NH/sub 3/, cyanides, aldehydes, NO/sub X/, and miscellaneous short-chain carbon compounds. The presence of fluorine-containing compounds leads to the emission of many other C-F and C-F-Cl compounds, especially carbonyl fluoride (COF). Studies indicate that CO, HCL, HCN, as well as aliphatic and aromatic hydrocarbons are potentially the most physiologically damaging. Other significantly toxic compounds include CO, formaldehyde, formic acid, phenol, methyl alcohol, and acetic acid. In general it is not carbon particles, CO, or CO/sub 2/ that are responsible for death upon inhalation, but low molecular weight carbon chain compounds such as aldehydes. Workers in pyrolysis combustion plants can be expected to be exposed to higher concentrations of toxic compounds than residents in surrounding areas. A comprehensive list of the compounds and elements that can be produced in combustion pyrolysis, including threshold limit values, is presented. These compounds cause serious environmental pollution but can be found wherever incinerators, small power plants, and even back yard leaf-burning fires exist. 49 references.