Reduction of toxic substances in tobacco smoke

A tobacco-filled smoking article having a mouthpiece end and an end to be lighted and being adapted to produce a low proportion of carbon monoxide in the gaseous products of combustion, comprising a tobacco filling and means for radially confining said tobacco, wherein within the volume of tobacco and spaced from said radial tobacco-confining means, there is at least one tobaccoless region separated from the tobacco by a substantially air-impermeable partition which remains form-stable under the effect of heat during burning of the tobacco in a combustion zone in order to prevent external air from passing through the partition into the inner region of the tobacco in the combustion zone and behind the combustion zone, said tobaccoless region being also substantially air-impermeable at its end adjacent the mouthpiece end of said smoking article, said tobaccoless region being filled with cellulose-containing material and the cross sectional area of said tobaccoless region being less than about 60% of the total cross-sectional area of said article.