The chapter describes an experimental study to evaluate performance characteristics of currently available controls for indoor air pollutants, including both particles and gases. The study evaluated the particle-size-dependent collection efficiency of seven commercially available devices for particulate control: a common furnace filter, four industrial filters, and two electronic air cleaners (EACs). The furnance filter had negligible effect on particles with diameters between 0.1 and 1 micrometer. The industrial filters, with ASHRAE ratings of 95, 85, 65, and 40% showed minimum efficiency at about 0.1 micrometer, which was substantially less than the ASHRAE efficiency. One EAC, essentially a furnance filter with a high-voltage electrode, reached a maximum efficiency of 30% at low flowrates (7 cu m/min); however, it had a negligible effect at higher flowrates. The other EAC, similar to an industrial ESP, showed efficiencies of 80-90% over the entire size range at low to moderate flowrates. At the highest flowrate, a minimum efficiency was detected at 0.35 micrometer. The study also evaluated the suitability of commerically available carbon-based sorbents (wood, coal, and coconut) for removing low concentrations of volatile organic compounds (benzene, acetaldehyde, and 1,1,1-trichloroethane).