Phase-out filter perforation: effects on human tobacco smoke exposure

Phase-Out is a mechanical device that dilutes the cigarette smoke stream by mechanically perforating cigarette filters. Machine testing of Phase-Out-treated cigarettes suggested that smoke exposure reductions of 90-95% could be achieved with the device. This study evaluated exposure to carbon monoxide (CO) and nicotine when humans (N = 10) smoked Phase-Out-treated cigarettes under controlled laboratory conditions. Using boost (i.e., change from baseline) measures of constituent exposure, reductions ranging from 30-80% were seen for both nicotine and carbon monoxide. Orderly graded reductions in constituent exposure were observed for both nicotine and carbon monoxide as the number of filter perforations increased from zero to six holes, with no further reduction at the eight-hole condition. Percentage reductions in constituent exposure generally corresponded well to those anticipated from machine testing, indicating that the controlled smoking technology was valid and that the Phase-Out device operated as expected in a human smoking assay. The utility of partial constituent-level reductions is discussed both with regard to lowered health risks of smoking and ease of quitting when partial reduction is used as a gradual weaning preparation for quit attempts.