Advantages and Disadvantages in the Use of Fourier Transform Infrared (FTIR) and Filter Infrared (FIR) Spectrometers for Monitoring Airborne Gases and Vapors of Industrial Hygiene Concern

Abstract The important differences between Fourier transform infrared (FTIR) and filter infrared (FIR) systems for air monitoring are explored, and the strengths and weaknesses of these technologies when applied to industrial hygiene problems are defined and illustrated with actual workplace air monitoring examples. The discussion of the differences in FTIR and FIR instrumentation is structured around the principal components of these spectrophotometers: the optical, sample, and data handling and interpretation systems. Workplace air monitoring applications that are discussed as illustrations of the relative utility of these systems are remote sensing at a hazardous waste site, emissions from a chemical vapor deposition furnace, irritating odors from resin regeneration, and trichloroethylene and Freon® samples from a degreasing operation. In addition, cautionary notes are given for the application of FTIR by nonspectroscopists. Finally, the direction of future research and technical advances are discussed.