Abstract: A filter element suitable for use as a cigarette filter includes at least one section of fibrous tow comprising at least one plasticizer, the plasticizer including a citric acid ester, such as triethyl citrate, present in an amount of no more than about 15 weight percent based on the total weight of the filter material, and an adsorbent material, such as a granular carbonaceous material. One exemplary filter element has two or more sections of cellulose acetate tow comprising triethyl citrate in an amount of no more than about 12 weight percent based on the total weight of the filter material, and a granular carbonaceous material dispersed within at least one section of cellulose acetate tow. Cigarettes incorporating the filter element and methods of extending shelf-life of cigarettes including an adsorbent material are also provided.

Abstract: A cigarette smoking article achieves very low levels of CO and other gas phase components by means of substantial air dilution, but has an acceptable pressure drop and sufficient delivery of particulate matter to provide a flavorful smoke. The filter has two sections, an upstream section which has substantially no pressure drop thereacross and a downstream section which provides substantially all the pressure drop of the filter. Dilution air is admitted to the upstream section of the filter to mix with mainstream smoke before it passes through the downstream section of the filter and thereby reduce the CO and gas phase levels in the smoke.