The Resource Conservation and Recovery Act of 1976 (RCRA) and its amendments require the U.S. Environmental Protection Agency to institute a program to control hazardous waste. Implementation of the RCRA will require reliable monitoring tools for the characterization of a broad spectrum of hazardous wastes. Accordingly, the capability of packed column gas chromatography/Fourier transform infrared spectrometry (GC/FT-IR) using the Gas Infrared Fourier Transform Software (GIFTS) to analyze complex hazardous waste extracts was tested. These extracts were also analyzed by gas chromatography/mass spectrometry (GC/MS) and the on-line library search results for both techniques were compared. GC/FT-IR was a powerful tool for aromatic isomer differentiation in these complex wastes. The GIFTS on-line library search correctly identified poorly resolved gas chromatographic effluent components. The magnitude of the GIFTS hit index difference between the first and second library search hits is a reliable indicator of the search validity. The combination of GC/FT-IR and GC/MS may provide the identification of all volatile components in complex environmental extracts.