A typical gas chromatogram of the volatile pyrolysis products (molecular weights less than 150) of untreated a-cellulose contains 39 peaks, however, mass spectral data indicate that at least 59 compounds are present. Since the initial pyrolysis products undergo decomposition, both initial and subsequent decomposition products are included in the analysis. A total of 37 compounds have been identified, 13 of which have not been previously reported. Most of the newly identified compounds contain a benzene ring indicating that these compounds may be products of reactions between initial volatiles. A comparison of the products generated in the temperature range 330º — 400ºC indicates that the formation of pyrolysis products is essentially independent of temperature. This means that investigations carried out at temperatures lower than the pyrolysis temperatures of a fire environment are meaningful as far as fire problems are concerned. In general, flame retardant treated samples produce fewer products than untreated samples, although the compounds that are present are the same. Some treatments, including 4% iodination, 6% benzhydrylation, and 4% iodination-5% benzhydrylation yield only five prominent compounds: water, acetic acid, furfural, 5-methyl-2-furfuraldehyde, and an unknown. Flame retardant concentration seems to affect the formation of products more than the type of retardant. Comparisons of the chromatograms obtained for untreated levoglucosan and cellulose indicate that most of the decomposition of cellulose probably forms levoglucosan which then decomposes to yield the observed pyrolysis products. In addition, the products of flame retardant treated levoglucosan are essentially the same as those of cellulose with the same retardant treatment. This suggests that the retardants act on the levoglucosan formed in the decompisition of the cellulose rather than on the cellulose directly.