We describe a technique that enables individuals to detect the number of puffs taken on a filter cigarette by comparing the "color" of the spent filter to a color scale that simulates the appearance of filters exposed to low-, standard-, or high-yield smoking-machine regimens. Average ratings of filters by 11 subjects correlated almost perfectly with the number of standard puffs to which the filters had been exposed. (Am J Public Health 1982; 72:597-599.)
A color-matching technique for monitoring tar/nicotine yields to smokers. Publishing Authors By Initials
