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FILE NAME Kent KNT DATE 1954 Nov DOC KNT030 DOCUMENT DESCRIPTION Unpublished External Report - Physical Properties of Cigarette Smoke ARN IF RESARCH RESARCH RESARCH F ATICN 0 Illinois Institute of Technology Techno Center Chicago 14 Illinois AFF Project No. C 593 PHYSICAL PROPERTIES OF CIGAFETTE OKE Summary Report November 1954 for P. Lorillard Company 111 First Street Jersey City 2 New Jersey Associate Chemical Engineer DEFENDANT'S EXHIBIT 2-21427 -2147 9672398 0127 PHYSICAL PROPERTIES OF CIGARETTE SMOKE PART 1 GENERAL DISCUSSION OF RES This project initiated in June 1953 has as its primary objective the study of the physical properties of smoke from Old Gold and Kent cigarettes The properties of the smoke particles of particular interest are size distribution concentration physical state and behavior on filtration Answers to these questions will not only provide information of general fundamental interest but will also yield data to help in the systematic development of improved smoking products For instance particle size distribution and concentration are very important in the development of filter cigarettes The physical properties of smoke particles are closely related to color and appearance of smoke its taste and the degree of its retention by the body Although there is relatively little information on its physical properties the chemical nature of cigarette smoke has been studied extensively An investigation of field appears to be particularly promising for new and use- ful information Over the past year and a half much has been accomplished in answering these basic questions It is now possible to characterize fairly closely the physical nature of the smoke as it leaves the cigarette The smoke con- sists of liquid droplets containing many extremely small solid particles The droplets are quite stable and are essentially of an oily nature The smoke itself behaves like a continuous fluid rather than an aggregate of par- ticulates in an enclosed air space showing a strong tendency to hang together and to settle rapidly through quiet air Microscopic and photomicrographic examinations of the freshly formed smoke show that most of the particles are less than 1 micron in diameter 10M 10MJ J 2 DESEARCH FOUNDA IN ve VOUS ITUTE > ECHNOLOGY ECHNOLOGY 9672390 1 0128 cut down This seemingly high loss of smoke agrees well with other studies on the loss of aerosols in the lungs Investigators also demonstrate that retention is reduced markedly as the particles become smaller than 0.5 micron This points out the importance of having sound fundamental data to understand understand adequately the behavior of cigarette smoke The interesting answers obtained on the subject of the quantity of inhaled smoke retained by the body brought up a problem of immediate practical use namely if the size of the smoke particles can be reduced would the retention be less at the same time Figure 11 shows that if the smoke particles could be reduced by several tenths of a micron smoke retention may be cut considerably Also this smoke should be rather mild and voluminous this may be accomplished by special selection of tobaccos addition of inert fillers to control the burning temperature or chemical extraction In studies at Duke University sponsored by the Demon Runyon Fund extraction with alcohol has been shown to reduce particle size Equipment to study the effectiveness of such modification is already available The chemical composition of cigarette smoke may vary with the particle size the moisture content of the tobacco the number of the puff and the type of cigarette le plain or filter tip Information on these variables is of great interest since the physiological effects of cigarette smoke are due to its chemical composition The present equipment can readily pro- vide samples for quantitative analysis and it may be possible to carry out qualitative chemical tests on individual particles by means of chemical microscopy In all this work the cigarettes were smoked at standard conditions but in actual use the smoking conditions may be far from standard Changing AqMJUAAqMJUA SEARCSH EARCH NOAT NOAT 74 OF tle NOS INSTITUTINSE TITUTE DE TECHNU TECHNU TSY 9672392 ~ 3 0130 the smoking rate and moisture content may change particle size and concentration considerably and there is some evidence that this is the case Therefore some study of these variables would make the present data much more complete and inclusive A graphic summary of the most important results and of some equipment is shown on the following pages These results and the techniques used in this program are discussed in detail in the second part of this report ARMOUR ASEARIN FROIN 138 OF fev GNST... IT UTE ... TECHNO10T6ECHNYO106Y -4- 967239 0131 Fig 2 KENT PUFF2 5H These taken lower photomicrographs are taken from smoke samples under identical conditions They snow the concentration and the somewhat smaller particle size of the Kent smoke 9672394 0132 Fig KENT PUFF 11 5M The photomicrographs as the preceding set and particle size as were taken under the same conditions and show the increase in concentration the cigarette is smoked 9672395 ARF ARF ARF 0133 0133 0133 4 t t an automatic cigarette smoker apparatus combines the smoke with This apparatus for accurately diluting with equipment obtaining special samples of smoke clean air and then and measurement The for detailed study particles center contains diluted smoke large flask lower through this flask indicates horizontal beam of light A moving slide A smoke concentration the approximate sampler is above the flask Fig 5 AUTOMATIC SMOKING MACHINE AND SAMPLING EQUIPMENT 9672396 0134 ERGUOATZS @UOS JO OF} [RAOWI PT D JO SOYBIZENTL *saTOQAed qusy PTO AST YydeasFuey esrE0D ou} oy} spuL Jo Jo egSL1-05T y 0ST-S2"T SYIDUd BN0nS (wo ilustraes removal efctivens of coarser 00 Suctoig UJIAvO ut 4 1~$29 ANAM eduey dO .OLNETUSIA MAASMASASASSSS $L0-CS"0 deqowetg o174ed 271s -- -- -- -- SOVEAV 9 7 1.50-1.75 cm 1.25-1.0 7 a0N 2? OL q5 fAQusNbaty ~ ARF-0135 600 a fi e centimeter 500 centimeter cubic cubic cubic per 400 - per Particles Particles 300 = Particles Hilion Hillion 200 Hillion Concentration Concentration 100 5 ConcetraionConcentration Concetraion Concentration .) t 1 2 old Kent lL i 3 h 1 l S 6 " k 7 8 Puff Number l l 9 10 11 Fig.7 Fig.7 SMOKE CONCENTRATION DATA ARMOUR Figure namely illustratesillustrates the main difference between the Kent and old Gold the much lower particle concentration of the Kent It should be noted that the difference increases as the cigarette is smoked In other words the tobacco acts as fairly effective filter but loses its effectiveness as the cigarette becomes shorter 9672398 RESEARCH FOUNDATION OF ILLINO15 INSTITUTE OF TECHNOLOGY 9 0136 0.008 cc Puf 0.006 per Particles 0.004- Smoke 0.002 of Volume Fig 8 Puff Number VOLUME OCCUPIED PY SMOKE PARTICLES The smoke particles in occupy half the volume from an Old Gold a puff of the from a Kent cigarette smoke particles in a puff 967239 - 10 0137 PTO PIO Be -80 MIS *SBunTQjous eypred = 18) axoUs of} Jo UT palequy pouThyar UoFAQs}e1 "ajynd oyQ JO 94e7E3TSUOTQ.eIy Fy JO 1agel CBABEP om PTO PID YFTq Joy Gold JesxweT_ PTOD O47 PLO SON larger quay a quey lenend PTO PTOD quay exoug syoug oT 8 SIONS GHIVANI KKeennttKent ToqEnH OHV GTIVHTA 40 JIN LHDIaM 6 a CZ *3Td paeuxg pateyu [Z 4 (] PTO pto9 L A 2 quay 967240 org 0 s oh Number oe o t Fig WRIGHT FIHALED axoug Jo SMOKE -ll- ARF-0138 6.0 old Gold milgrams 4.0 L Body by old Gold old Gold old Retained 3.0 Gold Kent Kent Smoke old Gold of Kent Weight Kent Rent 1.0 a ml 6 B 10 Puff Number Fig 10 WEIGHT OF SMOKE RETAINED AFTER INHALING 9672401 ARMOUR the difference between Kent and Old Gold cigarettes 10 illustrates Kent is very much lower FTiheguwreeight of smoke lost to the body from a largely because the smoke in a puff from a Kent weighs less RESEARCH FOUNDATION -- -- ILLINO15 INSTITUTE OF TELEF 12 0139 90 80 - Retained 70 F Particles of cent Per Particles beyond this range are mostly removed in upper respiratory system 40 0 0.5 1.0 1.5 Diameter of Particles Microns 10,000 cm ARMOUR RESEARCH Fig.ll RETENTION OF PARTICLES BY LOWER LUNGS Note This curve is for material of unit density For cigarette smoke the curve should be shifted slightly to the left FOUNDATION OF ILLINOIS INSTITUTE OF TECHNOLOGY 9672402 13 0140 @ ans Constanthead Water Supply Suction Burette Burette Ey Water Overflow Rotameter Moving Slide Impinger alr ol==0 f Vacuum Pump Diluter Clamp Chimney @ ' Syringe Syringe L \ = 5000 cc Sampling Cigarette Chamber [coma 1000 cc Flask Pressure Release od / o / / Filter Thermal Precipitator 7 = Lab fa) / 0 ; Timing Control Solenoid Valve (EL Rota- t S)=| meter = HL _e . Filter Compresse Compresse Air 9672403 1212 1 MACHINE 0141 peysodapyopye ppeuydetsas worly euyoen B{duuetsayoug uo J3yTy UOTINS Supjomgusqwy polEyut astdueg ~ sz suermg ayo qyspeu Floatci ee dung GS Rim tore 490 27%y Jayoug JetJet exyomg 079 uswny Be Exhaled TEEDSmoke ayous 22 04 CigareteCigarete Cigaretayoug Smoke BATBA fq qeoTa oy pe zamg pyouejosetedo 4 EXHALED Fig.13 EQUIPMENT BOT peo SMOKE Smoker euTyoey Tk Jupjous J2A0 - 15- SYIGNVS Machine SHmOokde @YONS LNandEtaGJFIVOHZS <12Ts 967240 04 ARF-0142 Fig 15 DUSTDUST COLLECTED FROM 1500 cc OF AIR FILTERED THROUGH AN OLD GOLD -. 7 ; i a ! * . v . . 10... Fig 16 DUST COLLECTED FROM 1500 cc OF FILTERED THROUGH A KENT WITH A FIZERS FROM THE FILTER AIR FEW 101 ASBESTOS 9672405 0143 FiFgig 17 FIFIBBERSERS FROM FROM A KENT FILFTILTERER THAT HAS NOT BEEN USED 5 Fig 18 A FIBER COATED WITH SMOKE SUBSTANCE 5 FROM A KENT FILTER USED FOR ONE PUFF 9672406 0144 PART 2 TECHNICAL DISCUSSION This part of the report gives some of the technical details of the research on the physical properties of cigarette smoke First an adaptation of the standard smoking machine was built that placed special emphasis on handling the smoke so that it is not altered after it leaves the cigarette and techniques were devised to sample and analyze this smoke The second phase involved the routine application of the equipment and techniques to many Old Gold and Kent cigarettes to obtain firm data on the size and concentration of the smoke particles This information was then used in a study of exhaled smoke to investigate the retention of the smoke by the lungs The various aspects of this project will be discussed in the following sequence equipment analytical procedures and discussion of results I. EQUIPMENT A. Smoking Machine An automatic smoking machine was built as pictured in Fig 5 and sketched in Fig 12 based on the standard conditions of a 35 puff in 2 sec at min intervals Other requirements were that the smoke should not be altered after it leaves the cigarette and that it should be possible to sample the smoke from every puff To meet the first condition the smoke is immed iately diluted by the volume of air in the 5000 flask to prevent agglomeration A quick blast of air breaks up the smoke that enters the flask in the form of a solid stream that does not mix with the surrounding air In order to sample every puff the machine has to be fully automatic This is accom- plished with a rpm motor that actuates a series of microswitches through a set of notched metal disks shown at the lower right of Fig 5. The switches operate the solenoid valves that ARMOUR RESEARCH FOUNDATION control the flow system Of ILLINOIS INSTITUTE in the machine OF TECHNOLOGY 9672407 15 - 0145 Sufficient suction to pull 35 cc of air through the cigarette is applied when water is allowed to run out of the suction burette by opening Valve 5 Fig 12 At the same time Valve 1 opens for 2 sec this is a special valve that gives a direct passage for the smoke There is a sec interval for sampling after a puff and then the large flask is purged of smoke with compressed air entering through Valve y and 2 and is exhausted through the pressure release tube which also serves as a manometer to indi- cate the resistance of the cigarette To supply standard amounts of smoke to human smokers for the study of exhaled smoke the manually operated machine Fig 13 is used When the solenoid valve is switched on 35 cc of water run out of the burette and displace a 35 cc of air through the cigarette from the air space following the solenoid valve The burning end of the cigarette is held in the shroud by the smoker just before a puff is due The smoker then receives the smoke and inhales B. Moving Slide Impinger A number of samplers were tested to collect the smoke for analysis Of these a moving slide impinger proved to be most successful for routine determinations of concentration and size distribution Weight samples of the smoke were conveniently collected by combining a membrane filter with an impinger The other samplers tested were a thermal precipitator an electrostatic precipitator and a settling chamber A moving slide impinger shown in the upper right of Fig 5 and 12 consists of a microscope slide that can be pulled at constant speed past a jet at right angles to the slide The jet directs the smoke onto the slide at close to sonic velocity The smoke particles impinge on the slide since ARMOUR RESEARCH FOUNDATION Of ILLINOIS INSTITUTE OF TECHNOLOGY 9672408 - - 0146 to follow the sudden change in direction of the gas their inertia is too high flow If a stationary slide were used the particles would pile up too fast and overlap Even in this case the smoke has to be diluted a second time after leaving the 5000 flask by a factor of 15 to prevent agglomeration surmounts the flask as seen in Fig 5 and 12 The diluter for this purpose C. Weight Sampler In order to collect all the smoke in puff and weigh it the sam- pler shown at the right of smoke is simply blown into Fig 13 has proven to be very convenient it while suction is applied to the filter Exhaled Exhaled For of inhaled smoke the cigarette is attached to the mouthpiece and samples suction is applied to the chamber with the smoking machine Then the sampling procedure is started The smoke passes through the jet at a fairly high a membrane filter and the rest is intercepted velocity most of it impinges on by the filter which can then be weighed A membrane filter Schleicher and Schuell is a nonfibrous surfaced filter with uniform tubular holes This arrangement was used because of its simplicity and availability The smoke could also be collected in a small cup facing the jet D. Thermal Frecipitator The thermal precipitator is reputedly 100 efficient for particles below 5 microns It collects aerosol hot wire that faces a cold microscope particles by thermal repulsion cover slip which serves as the from a collector deal of skill and time to operate but it is This instrument requires a good useful to check the efficiency of the impinger The instrument can be seen at the lower left of Fig 5 and 12 connected to a 1000 flask which in 9672409 turn is a 30 connected to the 5000 flask or so smoke sample pulled from The smaller flask the 5000 chamber serves to dilute with the syringe ARMOUR RESEARCH RESEARCH FOUNDATION -- --ILLINO15 INSTITUTE OF TECHNOLOGY - 20 - 0147 The smoke is mixed with the paddle then an aspirator connected to the thermal precipitator draws aerosol through it at 6 min for about 3 min E. Electrostatic Precipita Electrostatic precipitators are also nearly 100 efficient with this instrument all the smoke particles are collected on the walls of a tube connected to a high voltage source A central wire in the tube serves as the second electrode and repels the particles onto the wall The tube is large enough to accommodate a puff of smoke with sufficient dilution to prevent over- cm lapping of the particles on the wall about 4000 cm of wall area are necessary The tube in this case glass covered with aluminum foil on the outside is filled evenly with smoke and then the electricity is turned on to approximately 10,000 v The particles are collected on very small pieces of glass resting on the wall These pieces are coated with silicone to prevent spreading of the smoke particles However they are costed only on the side away from the tube wall otherwise no particles are collected F. Aerosol Settling Chamber A settling chamber was set up to study the gravity settling of the smoke particles For this purpose a glass cylinder filled with smoke is sub- merged in distilled water to keep the smoke at a constant temperature The cylinder is illuminated with a strong light beam to follow the scattering of light from the particles as an indication of the settling process II ANALYTICAL PROCEDURES A. Microscopy 9672401 All the smoke samples except for the scattering and weight samples have to be analyzed with a microscope Both electron and optical microscopy have been investigated The former has not shown too much promise ARMOUR RESEARCH FOUNDATION 0 ILLINO15 INSTITUte INSTITUte OF TECHNOLOGY - 21 - 0148 for routine work Difficulties are encountered in preparing a proper mount because of the volatility of the smoke under a high vacuum and because of its chemical composition Both factors make it difficult to prepare replicas Of the optical microscope methods field illumination gave the best results Bright illumination could not be used directly because of the very low contrast of the smoke particles mounted in air and the lack of a proper mounting medium Coating the slides with a dye that would be dissolved by the smoke was not feasible because the dye crystals could not be produced small enough without elaborate equipment Coating the particles with iodine crystals from iodine fumes gave good contrast but the iodine also made all the submicroscopic rough spots on the glass visible Phase microscopy gave negative results in a few initial tests possibly owing to the lack of a suitable mounting medium Since the darkfield method gave good results no further work was done in this field and no definite statement can be made on the usefulness of phase microscopy A Spencer 0.85 N.A. bispherical oiled field condenser with a Zeiss Neofluar 0.75 N.A. 40x objective proved to be the best optical combination The resolving power of the equipment is such that a Leitz Periplan 25x eyepiece is justified for the photomicrographic work The antireflection coating for reducing glare on the objective may account for its superior performance Glare is a problem since the condenser design specifies a liquid mounting medium To compensate for the air space between the cover slip and microscope slide in which the particles are located the eyepiece distance had to be increased from 160 to 175mm Kodak Super XX film is used for photomicrography with 2- min exposures ARMOUR RESEARCH FOUNDATION of ILLINOIS INSTITUTE O TECHNOLOGY 9672401 - 22 0149 The microscope slides have to be of the proper thickness and of the highest quality They must be cleaned thoroughly and coated with silicone to keep the spreading of the particles to a minimum B. Veight Sampling The analytical procedure for weighing samples of cigarette smoke is rather simple The filters are allowed to condition in the room atmosphere and are weighed just before and after sampling The passage of air alone through the filter does not change its weight The coarse type of membrane filter collects all of the smoke effectively III DISCUSSION OF RESULTS One of the first objectives of this research is to establish the particle size distribution and concentration of the smoke from Old Gold and Kent cigarettes This was accomplished with the moving slide impinger Then information on the amount of smoke retained after inhaling into the lungs appeared to be highly desirable To assemble the latter information weight sampling of the smoke proved to be the most direct method as every second exhaled breath could be sampled An over summary of the results appears in Table 1 Table 1 Cigarette Old Gold Kent Average Particle Size Microns 0.6 0.5 SUMMARY OF RESULTS - Average Average Con- Weight of centration Smoke per Particles Puff mg 440 million 3.8 Average Weight of Smoke Retained after Inhaling into the Lungs mg 3.3 280 million 2.1 1.6 ARMOUR RESEARCH FOUNDATION OF ILLINOIS INSTITUTE 05 TECHNOLOGY 96724012 - 23 ~ 0150 @) The particle size and concentration data are shown in more detail in Fig 6 7 and 8. Figure 6 shows the range in particle size and points out that Kent smoke consists of somewhat smaller particles Figure 7 demonstrates that the salient difference between the two cigarettes is the very much lower number of particles in the Kent smoke The photographs Fig 1-4 illustrate the differences between the two cigarettes Figure 8 gives the volume of the amcke particles in a puff These data can be converted to weight of smoke per puff to compare with the weight samples from the membrane filters Figure 9 shows the latter data which parallel the concentration data The weight of smoke per puff from the size distribution data is calculated to be higher however this would be expected because the particles are bound to spread from a true spherical shape on the slide The spreading factor appears to be close to 1.2 The difficulty in establishing this factor precisely is the lack of data on the density of the cigarette smoke in question The results from the study on exhaled smoke show that from 70 to 90 by weight of the smoke is lost when it is inhaled into the lungs This is based on the premise that all the smoke not retained by the lungs will be expelled in the first exhalation after a puff Experimental work has shown that smoke is exhaled in subsequent breaths but results to date show this amount to be negligible If the smoke is taken into the mouth only up to 20 by weight may be retained The particles exhaled from the lungs are smaller than the original These particle size data were obtained with the moving slide impinger the smoke was exhaled into the 5000 flask of the smoking machine Figure 9 demonstrates the high retention of smoke in the lower respiratory system while Fig 10 compares the weight of smoke retained from ARMOUR RESEARCH FOUNDATION Of ILLINOIS INSTITUTE Of TECHNOLOGY TECHNOLOGY 96724013 - 24 - 0151 Kent and old Gold cigarettes These graphs show that the retention of Kent smoke is about 10 less than that of Old Golds This may be due to the smaller size of the Kent particles Since there is much less smoke in a puff from a Kent the weight picked up by the body is much lower than that from an Old Gold It should be remembered that these results are from one male and one female smoker But the results seem to be applicable in general since they are in good agreement with what is known about the retention of aerosols by the lungs Figure 11 which clearly illustrates the importance of particle size in the study of cigarette smoke is a part of a report by W. B. Harris A.M.A. Arch Indus Hyg 8 445 1953 In the section on equipment some auxiliary sampling instruments were discussed The thermal precipitator was used to carry out concentration and size measurements at the same time an impinger sample was taken A successful procedure has been worked out for this work after some modification of the precipitator The heat from the hot wire of the thermal precipitator has no noticeable effect on the particles Both instruments seem to give the same results but a larger number of tests need to be made for a precise com- parison The electrostatic precipitator has a desirable feature in that the smoke can be sampled without going through a valve a second diluter and a high velocity jet On the other hand it is not a practical instrumefnotr routine work in this case After considerable effort the sampling technique was worked out Again general agreement was found with the impinger sampler Lack of time precluded any detailed comparison though 9672401 The aerosol settling chamber gave some quantitative results when smoke had settled from 5 to 30 min That is the light beam exhibited colored ARMOUR RESEARCH FOUNDATION OF ILLINOIS INSTITUTE 06 TECHNOLOGY 25 0152 bands indicating the presence of predominant particle sizes at various levels in the settling cylinder However the size data showed the presence of fairly large particles indicating that agglomeration was taking place Diluting the smoke sufficiently to prevent this makes visual studies difficult and furthermore with the smaller particles the operation of the settling chamber becomes very sensitive to minute temperature fluctuations In the course of this investigation a number of short studies were carried out one study concerned the filtration of atmospheric dust by unlit cigarettes On a particle count basis both Kent and Old Gold cigarettes removed about 50 of the dust However on a weight basis the Kent is very much more effective as shown in Fig 14 15 and 16 which demonstrate the filtration of the larger dust particles that make up most of the weight Figure 17 shows a few asbestos fibers pulled from the filter by the air stream When the extinguished cigarette is tested after one puff hardly any asbestos fibers are found Some work was done to follow what happens to the smoke particles caught by the Kent filter A filter was carefully opened above a microscope slide so many of the fibers would settle on it Examination showed tha in- dividual smoke particles are rather loosely attached to the fibers which are considerably smaller in diameter than the particles When enough particles are on a fiber they coalesce and coat the fiber Figures 17 and 18 show the asbestos fibers before and after the first puff of smoke 96724015 ARMOUR RESEARCH FOUNDATION O ILLINOIS INSTITUTE O TECHNOLOGY - 26 - 0153