A mathematical model was developed to describe pressure drop changes and retention of condensible vapor phase components for carbon-on-tow/cellulose acetate (CA) dual filtered cigarettes. The model uses the dynamics of vapor flow through the cylindrical CA and carbon-on-tow filter components to describe the physical system. The data from this study and from a study conducted at the laboratories of Baumgartner Papiers SA show the relationship between filter pressure drop and carbon loading. The data on individual vapor phase components is analysed to develop a model showing how filter efficiency is a function of the molar polarization and boiling point and how this function changes with carbon loading.