Wood combustion used for residential heating purposes is a significant contributor to local air pollution. It releases large amounts of gaseous and particulate pollutants into the atmosphere. While the characterization of primary emissions is well documented, few studies have investigated the atmospheric fate of the emissions from residential heating appliances and the subsequent secondary organic aerosol (SOA) formation. This is even more true in the case of pellet wood stoves by comparison to log wood stoves (Bertrand et al., 2017). The species contributing to the toxic potential of these primary or secondary particle emissions are still relatively unknown. If the toxicity of the polycyclic aromatic hydrocarbons (PAHs) and their derivatives (nitro- and oxy-PAHs) associated to the emitted PM is largely recognized, their quantification is rather limited and often not representative of the whole mixture toxic potential. In this context, the use of integrative tools based on biological responses (in vitro mechanism-based cellular bioassays) seems relevant to better evaluate the overall biologically active chemical aerosol mixture (Eichbaum et al., 2014). The main objective of this work was to assess and compare, using in vitro mechanism-based bioassays, biological responses of the primary and secondary emissions obtained from both, a log wood and a pellet stove.