The Diffusion of Carbon Monoxide out of Cigarettes

In some cigarette designs, diffusion of carbon monoxide out of a cigarette as the gases are drawn from their formation region towards the mouth end of the cigarette is more important than air dilution in controlling carbon monoxide mainstream delivery. The diffusion is a three-stage process: radial diffusion through the tobacco bed, diffusion through the paper, and diffusion away from the outer surface of the paper. Measurements have been made of the diffusion coefficient of carbon monoxide through paper, and the diffusion coefficient from the cigarette. The former has a value of 4.4 × 10