A six-week study was conducted at the University of Colorado Art Museum during which volatile organic compounds (VOCs), CO2, O3, NO, NO2, other trace gases, and submicron aerosol were measured continuously. These measurements were then analyzed using a box model to quantify the rates of major processes that transformed the composition of the air. VOC emission factors were quantified for museum occupants and their activities. Deposition of VOCs to surfaces was quantified across a range of VOC saturation vapor concentrations (C*) and Henryâs law constants (H) and was determined to be a major sink for VOCs with C* 102 M atm-1. Reaction rates of VOCs with O3, OH radicals, and NO3 radicals were quantified, with unsaturated and saturated VOCs having oxidation lifetimes of >5 and >15 h, making deposition to surfaces and ventilation the dominant VOC sinks in the museum. Ozone loss rates were quantified inside a museum gallery, where reactions with surfaces, NO, occupants, and NO2 accounted for 62%, 31%, 5%, and 2% of the O3 sink. The measured concentrations of acetic acid, formic acid, NO2, O3, particulate matter, SO2, and total VOCs were below the guidelines for museums.