This study investigated secondary air pollutants formed from reactions between constituents of terpene-containing household products and ozone. Gas-phase emissions from three different products were introduced along with ozone into a 198-L Teflon-lined reaction chamber. Gas-phase concentrations of reactive terpenes, terpenoids and oxidation products were measured. When the formulation contained more than one reactive VOC, their relative consumption by ozone was proportional to the initial reactant concentrations and to the rate constants of the respective terpene-ozone reactions. Formaldehyde was a predominant oxidation byproduct for the three studied products. Acetaldehyde and acetone were also detected when two of the products were exposed to ozone. A scanning mobility particle sizer measured particle nucleation events followed by a significant degree of ultrafine particle growth immediately upon mixing of reactants. Elevated concentrations of OH radicals generated by terpene ozonolysis were also measured.