The literature dealing with the gases emitted during pyrolysis of the more commonly usedfibers has been reviewed. In the presence of oxygen during pyrolysis, most fibers produce a variety of intermediate oxidation products, such as aldehydes, alcohols, ketones, ethers, and acids; and some fibers have sufficient oxygen in their molecular structure to produce these intermediates even in the absence of atmospheric oxygen. Most fibers also produce alkene or alkane hydrocarbon gases. Nitrogen-containing fibers produce cyanide-containing gases during pyrolysis. Fibers treated with flame-retardants generally produce the same gases as untreated fibers, but the volume distribution of the gases usually changes. -- AATA