Airborne Concentrations and Surface Arrival Rates of Organic Vapors in Clean Rooms

Sampling and analysis methods for characterizing vapor phase organic compounds in clean rooms have been developed. Two separate schemes have been devised to monitor airborne concentrations of organic vapors and the surface arrival rates. Airborne organic species are monitored using three stage Carbotrap collection tubes through which the clean room air is drawn using flow limiting orifices coupled to house vacuum. The species collected on these tubes are then thermally desorbed into a gas chromatograph/mass spectrometer (GC/MS) for identification and quantitation. Surface accumulation of organics is evaluated using a static surface-mounted collection device consisting of a thin charcoal pad under a Teflon membrane. From the data collected to date it is clear that both internal and external (outdoor) sources contribute to the flux of contaminants towards surfaces.