US7025067: Activated charcoal filter for effectively reducing p-benzosemiquinone from the mainstream cigarette smoke

A filter for tobacco smoke inhaling/generating/producing device, comprising stipulated amounts of specific grain sizes or combination of grain sizes of activated charcoal for effectively reducing from the mainstream smoke the level of p-benzosemiquinone (p-BSQ), a relatively stable highly reactive major harmful oxidant, without significantly affecting the flavor and taste of the smoke while providing comfortable mouthful of smoke and nicotine delivery, so that the charcoal filter cigarettes becomes potentially less hazardous safer cigarettes and may be acceptable to the smokers with marked reduction in health risk; the charcoal filters also effectively reduce the level of nitric oxide and tar from the mainstream smoke.