The impact of the formation of HO₂-H₂O adducts following reaction between H₂O and HO₂ and subsequent reaction of this adduct on HO_x, H₂O₂ and O₃ as a function of relative humidity in the marine boundary layer has been investigated using a zero-dimensional box model. The results of simulations with different product yields for the reaction of HO₂-H₂O with HO₂ were compared with base case data derived from current recommendations for tropospheric modelling. It is suggested that inclusion of reactions of the HO₂-H₂O adduct may provide a significant sink for HO₂ which has so far not been considered in models of tropospheric chemistry and depending on reaction products may have a significant impact on H₂O₂ and O₃.