Detection of vent-blocking on light and ultralight cigarettes.

Trained raters can reliably identify vent-blocking in ultralight cigarettes based on tar stain patterns, yet detection of this phenomenon has not been previously studied in light cigarettes. This study was conducted to extend the research on vent-blocking in ultralight cigarettes to the much more popular light cigarettes. We wanted to find out if individuals could discriminate among stain patterns on cigarette butts with unblocked (0%), partially blocked (50%), and fully blocked (100%) vents using both light and ultralight cigarettes. Subjects were able to use the stain pattern technique to detect vent-blocking in light cigarettes as well as ultralight cigarettes.