Estimating the hazards of "less hazardous" cigarettes. I. Tar, nicotine, carbon monoxide, acrolein, hydrogen cyanide, and total aldehyde deliveries of Canadian cigarettes.

The tar, nicotine, CO, HCN, total aldehyde, and acrolein deliveries of 102 brands of Canadian cigarettes have been determined. On the basis of these deliveries, 15 brands (9% of sales) were categorized as low hazard and 9 brands (10% of sales) as high hazards. All six constituents were used for the classification since for most brands tar was a poor indicator of gas-phase deliveries. As a result, smokers who indiscriminately switch to a brand with a lower tar delivery may inadvertently increase their exposure to gas-phase constituents such as CO and increase their risk of smoking-related pathology. With respect to Canadian cigarettes, the choice of a 30-mm standard butt length may result in omission of some of the available tobacco from the testing procedure, thus reducing the value of tar level as a guide to choosing a less harmful cigarette.