Cigarette Smoke Formation Studies: V. The Effects of the Cigarette Periphery on Mainstream Smoke Formation

The effects of the cigarette periphery on smoke formation have been experimentally studied. A series of cigarettes was prepared with carbon-14 labelled materials placed in different radial positions within the rods. These cigarettes were smoked and the distribution of the radioactivities into total smoke was measured. These data lead to the following conclusions: [1 ] The periphery plays a large contributing role (though not the sole role) in the formation of a) the mainstream particulate phase, b) sidestream particulate phase (derived from non-distillable/non-sublimable materials), and c) mainstream gas phase (derived from non-distillable/non-sublimable materials) ; [2] The central portion of the cigarette rod plays a large contributing role in a) sidestream gas phase and b) sidestream particulate phase (derived from distillable/sublimable compounds); and [ 3 ] The mainstream gas phase yields from the distillable/sublimable compounds are due in large part to the pyrolysis/combustion products formed during the static burn period. These products are carried into mainstream smoke by the incoming air at the beginning of the puff and by diffusion due to the pressure gradient existing in the cigarette during static burn. These experiments have demonstrated the significant effects that the central portion of the cigarette rod has on sidestream smoke formation and, conversely, the effects of the periphery on mainstream smoke.