How are tar, nicotine and carbon monoxide measured?
A laboratory smoking machine is used to ‘smoke’ a number of cigarettes by an internationally recognised standard method. The smoke from cigarettes contains many tiny particles which are collected on a special filter pad, while the gases pass through the pad to allow the separate measurement of carbon monoxide. The residue of particles on the pad, including nicotine and water, is measured. The nicotine and water are then extracted and measured. The tar yield for printing on the cigarette pack is calculated by subtracting the amounts of nicotine and water from that originally collected on the filter pad.
