Catalytic oxidation is an efficient remediation technique of industrial VOC emissions Catalyst performance is generally assessed measuring VOC conversion or CO2 emission, but not the formation of by-products. Untargeted toxicological validation of catalyst by coupling it to an Air-Liquid Interface exposure system. Using biological system allows integrating synergy and antagonism in toxic effects of emitted VOCs and by-products. CYP1A1 induction in exposed A549 cells showed the formation of PAHs undetected by chemical methods.