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MEASUREMENT OF THE DECREE OF VENTILATION OF CZGARETTES AT VARIOUS FLOW RATES REPORT NO. RD. 1576 RESTRICTED 14 .~.1978 AUTHOR: D.E. Creigh~on ISSUED BY: R.E. Thornton PROG. REF. : 12.02.27 DISTRIBUTION Dr. S.J. Green Dr. I.W. HuEhes Dr. E.A. Sanford E.M. G£bb, Esq. E.S. Wade, Esq. E.G. Ni=holls, Esq. Herr E. R/~uershaus Dr. F. Seehofer ~Lr. A.J. Kruszy~ski Dr. C.J.P. de Siqueira Dr. D.G. Pelion Library Copy No. i I! I! 2 " " 3, 4 I! II " " 6, 7. 8 " " 9, 10 " " Ii " " 12 " " 13 " " 14 " " 15 " '~ 16, 17 COPY NO.: O C~D Cr~ BAT Co LTD - MINNESOTA TOBACCO LITIGATION

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DECICALI4BD-6 Group Research & Development Centre, Britlsh-Americsn Tobacco Co. Led., SO--TON. 14th April 1978. MEASUREMENT OF THE DEGREE OF VENTILATION OF CIGARETTES AT VARIOUS FLOW RATES (Repute No. RD.1576 P~scricced) S~Y A rapid and simple method for measuring the degree of ventilation for a cigarette at a range of flow races has bean developed. The method uses the puff duplicator developed in eha Group R° & D. Canute, SouChampeon in an unconventional mode. The method described has been used to measure the ventilation patterns for 8 limited number of co~,erc£al cigarette brands. For cercaln of theme brands che ventilation decreases with increasing flow rand, thereby offering the smoker some scope for compensation. Although the effects are small (typically of the order of IOZ) they could be relevant to the design of acceptable low delivery produces. Consideration should therefore be given to the construction of purpose built equipment for seccinK up ehis procedure as a standard method. BAT Co LTD - MINNESOTA TOBACCO LITIGATION cZ~ Co O',, ",..C)

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-2- THE MEASUl%~4ENT OF THE DEGREE OF VENTILATION OF CZGARETTES In many developed countries cigarettes are designed to meec delivery targets when smoked by standard smoking machines, and hence co occupy a position in a league table that offers the manufacturer a marketing opportunity. Many of the desi~ for low dellve~y cigarettes use ventilation co dilute the smoke wlth air. This venciZation may be introduced by either perforating the cigarette filter with a band of holes or perforetlnS the paper used to wrap the cigarette rod or e combination of both. The higher the paper porosity or ventilation of the filter ohm more dilute the smoke delivered no the smoker. We have found a trend within the department for smokers to increase the volume of smoke drawn from cigarettes as the standard deliveries have been reduced by manufacturers. This trend can be seen by comparing a survey within the department (I) with the ~esults of & three month study on smokers who chansmd brends (2) recorded some three years apart. We a~so observed in (2) a degree of compensation for reduced delivery when a ventilated cigarette was smoked. Ventilated cigarettes generally have a lower draw resistance ac a given velocity than unventilated cigarettes and draw-resistance has been shown to affect the way in which ci&arettes are smoked. Increased draw resistance and a reduced machine smoked delivery resulted in reduced puff volume (3) whereas reduced draw resistance at constant standard delivery resulted in increased puff volume (&). Additionally, Dunn (5) has shown that when smokers are switched Co a cigarette of reduced draw resistance, there is a significant increase in mouth nicotine intake. GO BAT Co LTD - MINNESOTA TOBACCO LITIGATION

INDEX HAS INDICATED GAP IN BATES RANGE HERE

-3- From the foregoing it can be assumed chat, due co the interaction between smokers and the cigarettes that they smoke, cigarettes are unlikely to be smoked by people in the same way as a standard smoking machine. We have not yet observed a smoker who smokes to the same patterns as a standard smoking machine. In the case of ventilated cigarettes this will mean that the degree of ventilation may vary according to the velocitywith which people smoke them. It would, therefore, seem useful to have available a method to measure the degree of ventilation of a cigarette at different velocities Co cover the range of both the standard smokinsmachine and human smokers. The puff duplicator developed in Southampton (6) has the right facilities, £ncluding a flow feedback correction loop, to use for such studies and this application offers a rapid and simple method to measure the ventilation of a cigarette, over the range of flow rates employed by either the standard smoking machine or the hmnan smoker. METHOD An appropr£aCe pressure reading is fed into the pressure memory store of the puff dupl£cator so that i~ may draw a flow race of 50 m 1/sac through a capillary reslstance of 16 cm W.G. (at 17.5 ml/sec). The valve zero is adjusted and the flow feedback circuit calibrated so that the setting of the edge switches agrees with the flow displayed on • rotameter sleeved onto the cigarette holder. The flow feedback loop is then calibrated and operation of the edge switches will set a continuous flow through the cigarette holder at the val~e indicated,by the edge switches almost irrespective of the draw resistance of the cigarette in the holder. BAT Co LTD - MINNESOTA TOBACCO LITIGATION / (...r'l O'~

INDEX HAS INDICATED GAP IN BATES RANGE HERE

-&- The cigarette co be rested is fitted into the c£garecce holder and a short lensth (50 ~) of latex sleevlns screeched over the flnal 10 of the cisarette rod. A capillary draw resistance typically with a value equal to about half the draw resistance of the tobacco rod may be fitted into the latex sleeve to simulate the increase in draw resistance due to lighting. The other end of the capillary resistance is then connected by rubber tube to the upper end of a rotamecer which is open to atmosphere at its lower end. A d£asram of the exper£mmncal confisuracion is shown at the end of this report as Figure L. The cigarette holder is switched from the free smoking to restricted position and the edge switches operated to set flow through the bolder from 50-10 ml/sec in 5 ml steps. The rot-meter readings are recorded and compared with the settings on the edge switches and may be expressed as percentage ventilation by: r Flow measured on roCameCer 100 - "Flow called for in cigarette holder x 100) = Z ventilation The relative contributions of the paper porosity and the ventilation ports in the filter may be determined by measuring the total percentage ventilation as described above, mud then coverinK the vent£1aclon holes in the filter with tape ("Sel~otape") and remeasurlng the flow into the cigarette end ac the same range of flow rates as used previously. Using the same formula as shown above the contribution of the paper porosity may be calculated and, by subCractlon, the contribution of the ventilation ports in the filter. BAT Co LTD - MINNESOTA TOBACCO LITIGATION O c_r'l Co

INDEX HAS INDICATED GAP IN BATES RANGE HERE