Chapter 3 
the enemy of the good. There is a strong social case for encouraging 
manufacturers to develop safer cigarettes that will sell." If we take this 
premise as a realistic approach to the tobacco and illness dilemma in our 
Nation, how can our regulatory agencies effectively protect the consumer 
and on what type of measurement should risk assessment from cigarette 
smoking be based? This is the question to be resolved. The authors hope 
that presentation of some historical background will assist with this aim. 
QUESTION-AND-ANSWER SESSION 
DR. HENNINGFIELD: Dr. Hoffmann, the influence of some parameters, 
such as increasing puff quantity, would be pretty obvious for their impact; 
you would take in more smoke. But what about the factor of changing the 
intensity of a puff? For example, the FTC method uses 35 mL over 2 seconds, 
or say about 18 mL per second. What would be the impact of tripling the 
intensity by going to, say, 60 mL per 1 second? 
DR. HOFFMANN: This has been done by various groups, including 
Dr. Benowitz, Dr. Auston, and Dr. Ogg. All have shown that when you 
smoke more intensely (I think one report makes up to four or five puffs 
per minute, with puff volumes up to 55 mL), you obviously increase the 
smoke yields for cigarette smoke; based on epidemiological observations, 
but you inhale deeper. 
Now, this is reflected in the yield of nicotine respectively as one of its 
major metabolites. And in fact, R.J. Reynolds Tobacco Company has recently 
shown a very low yielding cigarette. They determined 90 percent of all 
metabolites, and I think the results are in here. They have shown that with 
the very low yielding cigarettes, the smoker inhales more than one would 
expect from machine smoking data, based on the nicotine metabolites. 
Machine smoking data may be all right for the cigarette without a filter 
tip, but based on all these studies (I think there are eight all total), the 
smoker of a low yielding cigarette inhales deeper and takes more puffs, 
smokes more intensely. 
DR. RICKERT: Dr. Hoffmann, I think you were intimately involved in the 
NCTs less hazardous cigarette program a number of years ago. Why was 
that program abandoned? 
DR. HOFFMANN: The timing was not right — I do not know the details. 
I work in the laboratory, and that is outside the field. It was purely politics. 
DR. HARRIS: Dr. Hoffmann, you presented trends in some cigarette smoke 
components over time. What do you know, if anything, about gross 
characteristics of cigarette smoke, such as the trends in the pH of American 
cigarette smoke or in the oxidation reduction potential of smoke? 
DR. HOFFMANN: The pH has increased slightly; it is slightly higher in 
filtered cigarettes, in perforated filter cigarettes, and in RT. 
33 
VAIIM 
