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Elasticity and 
Canadian Cigarettes

Introduction

A cigarette is best described as a nicotine delivery device (Smoker Compensation Study, 464562830).   Smokers smoke for nicotine. 

 As a nicotine delivery device, the quality of a cigarette can be measured by how effectively it delivers nicotine to the smoker.   Many factors influence the delivery of nicotine.  The type of leaf, the packing density of tobacco, the type of paper, the diameter of the cigarette, and the pH of the smoke are just a few of the variables that change the delivery (Smoke Dose Nicotine, 80192105). 

 While some of the nicotine delivery is determined by the design of the cigarette, the smoker can influence the nicotine delivery.

 The quantities of tar and nicotine listed on tobacco package are derived from tests outlined by the International Standards Organization (ISO).  ISO testing does not reflect how people actually smoke: “No smoker has yet been observed who smokes with the same pattern as a[n] [ISO] smoking machine.” Smoker Compensation Study, 464562830).  

The smoker can, consciously or unconsciously, control the time taken in between puffs (puff interval or frequency), the depth of inhalation of smoke[1], the duration of the puff, and the amount of smoke in a puff (puff volume) (The BAT Stance on Compensation, 89290242).  The smoker can also block the ventilation holes in the filter with his lips or fingers, which increases delivery.

The smoker can alter significantly the delivery of cigarettes as each control changes the chemistry.  For instance, when a larger puff is taken, (an increase in puff volume), the following occurs with cigarettes:

  • increase of smoke transport from coal to mouth end.

  • alteration of the smoke formation and transfer

  • increase of the burning velocity

  • alteration of the dilution processes (Schneider, p. 575251613)

The smoker can use the controls to regulate the amount of nicotine delivered from a cigarette.  Too little nicotine and the smoker is unsatisfied, too much and the excess of nicotine can make the smoker feel sick.  When the smoker self-regulates the amount of nicotine he/she is receiving, then the smoker is “compensating.” In Germany, when price was raised in the 1980’s, the tobacco companies found that compensation of cigarettes increased as smokers made the most of the nicotine of each cigarette.  (Smoking Behaviour Marketing Conference, 53600018 )

 Smokers, on average, require around 0.9 mg of nicotine a cigarette.  Overall, this means that many cigarette smokers will compensate down, especially those who smoke regular strength cigarettes.  While 30% of smokers do not compensate at all, smokers of light and mild cigarettes are likely to compensate up (Nicotine Conference, 100535068).  However, there are big differences between the different puffs on a cigarette.  Early puffs are larger and are where the smoker obtains most of the nicotine.  For later puffs, the puff volume is reduced substantially and the smoke inhales less deeply.  (Smoking Dynamics, 650000948)

Smokers perceived satisfaction is determined by the tar to nicotine ratio (t/n ratio), which is found by dividing the tar by the nicotine. One of the difficulties in reducing tar and nicotine level is that the tar to nicotine ratio is often increased in the process, which leads to a smaller impact (Effect of Changing Puff Volume on Tar Nicotine Ratio, 570267748).  This makes low delivery cigarettes less attractive to many smokers.

Another “bonus” for a low t/n ratio is that the pH of the smoke will increase.  A higher pH means that nicotine will be more easily available to the smoke.  Thus, a cigarette with a low t/n ratio will deliver a bigger “kick” than a cigarette with the same nicotine content, but a higher t/n ratio (Correlation of pH with Impact and Sales, 2041197305). Consequently, a “low delivery” cigarette will have the impact as a regular strength cigarette if it has a low t/n ratio.

The tobacco companies have researched the different methods with which people smoke for more than 30 years. Imperial Tobacco and other tobacco companies have known since the early 1970’s that smokers will compensate for nicotine in lower delivery cigarette (Frieri Smoking Machine, 650007425).    That is, a smoker will smoke a low nicotine cigarette harder, increasing the puff volume, in order to obtain more nicotine from it.  In general, smokers, however, do not like to exceed more than a 25% increase in puff volume and do not increase their puff when it becomes too much effort (Frieri Smoking Machine 2 , 650007456).  As the puff volume increases, the pressure required to take the drag also increases. This means that there is a natural limit to the ability to compensate by taking a bigger puff.

Elastic cigarettes overcome this problem as a small increase in puff volume produces a larger than expected hit of nicotine. Elasticity makes the smoke, rather than the smoker, work harder.

Elasticity is a measure of increase in deliveries to the smoker when a larger puff is taken: “Elasticity is the amount of smoke a smoker can take out of a cigarette” (Gonterman, 570252204).  Elasticity has been applied to nicotine, tar, total particulate matter, and tar/nicotine ratio.

It has been a major goal of tobacco companies to produce a cigarette with relatively low ISO numbers, high elasticity, and low t/n ratio.  “From a research and product development viewpoint the proposition of designing a cigarette, of high taste to tar ratio [i.e. high n/t ratio or low t/n ratio], which responds positively to human smoking behaviour [i.e. elasticity and compensation] has been agreed to be acceptable.  This is necessary if we are to explore and understand what consumers are seeking from cigarettes they buy.”  (The BAT Stance on Compensation, 89290241)

In the files released by the tobacco companies as a result of litigation in the U.S.A., Imperial tobacco, the makers of the largest selling cigarette brands in the Canada described a working formula for elasticity in a 1994 research report.  The report described elasticity in this way “If the tar delivery increases in direct proportion to the increase in puff volume, the product is inelastic (i.e. elasticity = 1), while if tar delivery increases faster than puff volume, elasticity > 1” (ITL Progress Report, 402415194). In other words, by increasing the puff volume, the smoker gets a greater than expected amount of nicotine, tar or any other chemical present in the smoke.

Elasticity = ∆ delivery /  ∆ puff volume

Imperial Tobacco and the other tobacco companies, however, have denied that they ever used their knowledge to deliberately make and market elastic cigarettes. 

Method

In 2001, Physicians for a Smoke-Free Canada undertook to investigate if there were elastic cigarettes in the Canadian market place and if so, what was the extent of their market share.

Puff volumes, nicotine and tar deliveries were obtained from the 1996 report “Determination of Cigarette Yields under Realistic Conditions” by W.S. Rickert from Labstat Inc.

Puff volumes of 44 ml and 56 ml were chosen in conjunction with the Labstat documents as being the level of normal and intense smoking.  Other than puff volumes, all other variables were held constant. 

There are a number of methods used to calculate elasticity.  BAT used a percent change of the substance from a lower volume to a higher.  Elasticity used here is one used by Brown and Williamson, a BAT subsidiary, which uses a definition of normalized elasticity that allows for better comparisons across brands. (Gonterman, 570252205)

Elasticity  = (N2/P2) x (P1/N1) x V1/V2   

Where:

  • V1 = puff volume of 44 ml

  • V2 = puff volume of 56 ml

  • N1 = delivery in mg at 44 ml

  • N2 = delivery in mg at 56 ml

  • P1 = number of puffs at 44 ml

  • P2 = number of puffs at 56 ml

 A cigarette that has an elasticity of over 1.00 is said to be elastic.  A number above 1 indicates that the increase of nicotine (or other chemical of interest) is proportionally greater than the change in the puff volume.

 Other definitions of elasticity were tested and produced similar results. 

 Sales data were taken for the year 1996 to match with the same cigarettes tested.

Results


Of 115 Canadian brands tested, there were 26 brands with an elasticity greater than 1.00 (22.6%).  But elastic cigarettes account for two-thirds (67%) of sales, a total of 31 billion cigarettes a year.

The elastic cigarettes have median sales of about 728 million cigarettes per brand.  Non-elastic cigarettes have median sales of 102 million.  

16 of the top 20 selling cigarette brands, which account for 61% of the market, are elastic.

None of the 20 least popular cigarette brands are elastic.

38% of Imperial Tobacco cigarette brands are elastic; only 24% of the brands produced RBH are elastic and only 8% by JTI-MacDonald. At 70%, Imperial has a commanding lead in market share of the Canadian cigarette market.  14 of the 20 top selling brands are Imperial’s.  All but one of them are elastic. 

(See Table of Results)

Discussion

  In 1966, tobacco company scientists noted that nicotine delivery was not greatly affected by increases in puff volume, while tar was increased (The Effect of Change in Puff Volume on Smoke Chemistry, 570512247).  In other words, in the average cigarette, tar levels should increase faster than the nicotine levels with an increase in puff volume.  This means that the t/n ratio increases and a big drag means a less satisfying smoke. 

However, in the top selling brands of 1996, the reverse occurs.  Nicotine increases at a faster rate than tar deliveries.[1]  Thus, a bigger drag on the cigarette will lead to a lower t/n ratio and a “better smoke”.  Cathy McBride, a scientist at Imperial Tobacco, reported that smokers were switching almost exclusively to cigarettes with low t/n ratio (Nicotine Conference, 100535058)

Elastic cigarettes means that the smoke works harder for the smoker, making it easier to attain and maintain appropriate levels of nicotine.  Also, when combined with low tar elasticity, cigarettes with high nicotine elasticity lead to a decrease in tar/nicotine ratio and more satisfying cigarette.  These types of cigarettes represent the goal of millions of dollars of tobacco company research.  

British American Tobacco (BAT) and its Canadian, American, and German subsidiaries were aware of design modifications that would affect elasticity (Elasticity Definitions, 575251615) (The BAT Stance on Compensation, 89290244).  Elasticity is a summary statistic and a high elasticity could emerge from a series of cigarette design modifications.  Elastic cigarettes could also result from test and focus groups choosing cigarettes that happen to be elastic, rather than a purposeful design.  However, BAT and its subsidiary companies were aware of design modifications to produce elastic cigarettes.  In Canada, over half of Imperial Tobacco brands are elastic compared to only a quarter of brands for the other Canadian companies

Elasticity does not “cause” a cigarette to sell well.  What the data indicates is that to be successful in Canada, a cigarette brand needs to be an effective nicotine delivery device. Elasticity is a good summary measure of the effectiveness of nicotine delivery. 

Canada is a good test country for comparing sales data to elasticity because of the general uniformity in the tobacco market.  Most Canadian cigarettes do not have flavourings other than menthol and most use the same type of tobacco (Virginia Flue-Cured).  Also, price is regulated in Canada and most cigarettes are sold for the same price.  This reduced the variables in the experiment. 

In conclusion, while only 23% of cigarettes brands are elastic, those brands sell very well: 67% of all cigarettes sold are elastic.  16 of the 20 top-selling cigarette brands are elastic.

Elasticity is necessary for high efficiency in the delivery and regulation of nicotine.

Elasticity makes becoming and staying addicted to nicotine much easier.

An elastic cigarette encourages increasing puff volume to decrease the t/n ratio; the smoker then draws a larger amount of smoke into their lungs than they would have otherwise which further increases the risk of smoking.  

In 1983, BAT decided that its stance on compensation was that it was a matter of adult choice (The BAT Stance on Compensation, 89290241). Elastic cigarettes, however, deliver tar and nicotine at levels unexpected by the smoker.  A smoker may think that switching to a lighter cigarette will help them “cut down” on smoking, but elasticity helps ensure that the smoker maintains full levels of nicotine.  Instead of the choice between quitting and smoking, the smoker is offered the illusion of a midway point that does little or nothing to lower nicotine intake and may in fact pose an even greater health risk because of the increased amount of smoke inhaled and further postponement of smoking cessation.

Bibliography

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