We investigated the reactive uptake of NO3, N2O5, NO2, HNO3, and O3on three types of solid polycyclic aromatic hydrocarbons (PAHs) using a coated wall flow tube reactor coupled to a chemical ionization mass spectrometer. The PAH surfaces studied were the 4-ring systems pyrene, benzaanthracene, and fluoranthene. Reaction of NO3radicals with all three PAHs was observed to be very fast with the reactive uptake coefficient, , ranging from 0.059 (0.11/−0.049) for benzaanthracene at 273 K to 0.79 (0.21/−0.67) for pyrene at room temperature. In contrast to the NO3reactions, reactions of the different PAHs with the other gas-phase species (N2O5, NO2, HNO3, and O3) were at or below the detection limit ( ≤ 6.6 × 10-5) in all cases, illustrating that these reactions are at best slow. For NO3we also investigated the time dependence of the reactive uptake to determine if the surface-bound PAH molecules were active participants in the reaction (i.e., reactants). Reaction of NO3on all three PAH surfaces slowed down at 263 K after long NO3exposure times, suggesting that the PAH molecules were reactants. Additionally, NO2and HNO3were identified as major gas-phase products. Our results show that under certain atmospheric conditions, NO3radicals can be a more important sink for PAHs than NO2, HNO3, N2O5, or O3and impact tropospheric lifetimes of surface-bound PAHs. [ABSTRACT FROM AUTHOR]