Tobacco Documents Online

-7- t "off-taste" due to charcoal depends on at least two factors: i. The discharge of negative taste components to the main smoke (e.g. dust) 2. The removal of positive taste components from the main smoke ( "unbalanced smoke"). Attempts were made to reduce the "off taste" due to charcoal by means of flavouri~g agents or other additives: a) Flavour: The essential oils from dill, sage and parsley (?) provided good results. An appropriate f~avouring recipe has been developed, by way of proposal. Since however no suitable tobacco mixture is at present available for experiment, the further development of this theme has had to be put off for the future. b) Additives: It has unexpectedly been discovered that an impregnatior~ of the charcoal with triacetin leads to a marked red~ction in the r'charcoal taste". The reasons for this • effect are not yet known; it also remains to see whether the treatment results in a decrease~of the adsorption " efficiency. The test was carried out on TEMPO cigarettes C~A) • In connection with this paragraph, it is still necessary to mention an observation which is obviously typical and reproduc- ible, although at the present time only theoretical considerat- ions can be contributed for its explanation: When one enters a room in which cigarettes with c~harcoal filters had previously been smoked, the impression of the cold smoke in the room is characteristically different, in an unpleasant manner, compared with the normal smell sensation. This fact clearly indicates that considerationmight from the outset have to be extended to a deliberate aromatisatlon of the side smoke from cigarettes with charcoal filters. CD ~O O~ ~O CD O ...... J

AMERICAN ClIARCOAL FILTER CIGARETTK'S Brand Lark Duke of ~urham Devon York TemDo Galaxy Multifilter ~ultifilte~ 2 York I,uclry StriWe Hamburg, Pf/Heu Type of filter Charcoal taste Chamber Hardly any Chamber Chamber Double/bonded Double/bonded Double/black acetate with gran- ulated charcoal II II U Double/white acetate with gran- ulated charcoal Triple/acetate with charcoal dust 4 December 1984 Absolutely Getectabls Absolutely detectable Present to medium extent Strongly marked ~resent, light to medium Absolutely detectable Present to medium extent Hardly any Strongly marked Unde si rable taste of main smoke during pauses between puffs None ~resent, though affected by flavou~ Present Some present Present to e stronger extent Some present PreseDt Some present Some present Present to e s~ronger extent After-taste None Present Hardly ~resent Pre sent Present to a stronger extent Some present Pr e s ant Present None Present to a stronger extent Tobacco end flavour taste Present None Hardly present Still present None ~rese~t Hardly present Still present Present. Notob~cco taste, but flavour taste Remarks Charncter o f cigarette deter- mined by flavou Undistin@uished cigarette Undistinguished cigarette, spar from menthol effect About equal dis- tribution of charcoal end tobacco taste Charcoal taste predomlna~es Charcoal taste overshadows tobacco taste About equal dis- tribution of charcoal end tobacco taste Charcoal taste combined with flavour ssste

J Physlosl examlnation of charcoal filters Brand Filter t~pe designation .... • , Devon S-Piece Ifelth Acetate/charcoal granulea/acetnte Tempo Bo~ded Charcoal Acetate/bundles ~f charcoal~rf~lule~ York Oomp~essed Charcoal " / " " York Charcoal Acetste/scatate covered with charcoal granules Avalon Triple Acetate/acetate w~Ith charcoal dust/paper Philip Multifi Acetate/acetate with Morris Lark Galaxy Riggio Lucky Strike charcoal granules 3-Piece Keith Acetate/charcoal ~hndles/acetste Double-Fi Acetate/acetate with ------~srcoal granules ChBrcoal Acetate/bundles of charcoal granules Charcoal Acetate/acetate with charcoal dust/acetate 14.7.64, 3.12.64 Fi it er ~fth /6/7 20, i0/i0 20, lO/lO 20, i0/I0 ~o, s1915 20, 7.5/ 12.5 20, 7.5/~ /V.5 90, 8/12 16, 8/8 ~0, 5.5/ 10/4.5 Fil~er diameter (mm) Whole 8.05 8.].0 8.i0 8.].0 8.15 8.05 8 .i0 8 • 05 8.i0 8. O0 Draw resistance (mm H20) of Acetate Paper" section -, section fil~er 55 V5.2 4O 47.8 13.8 x 2 50.0 20.V 23.5 rharcoa~ sectionJ 24.4 (osZo) 26.5 64.2 22.2 V4.6 24.4 80.4 38.4 x 2 13.7 40.0 3.6 (tale} 68.6 32.0 38.6 23.V 48.3 22.0 (talc) 36.0 14.9 (calc) 26.3 25.3 A/ Weight OverallI 0.31V 0.325 0.361 0.244 0.23V 0.315 0.331 0.317 0.273 0.216 (gm} Charcoa~ pieces 0.134 0.2VI 0.120 O. 080 0.192 0.108 0.161 0.098 (÷ sheath t0069£ 0

To Mr. Borowski Main Laboratory, Bahrenfeld Internal report from Raw Tobacco Dept. .... Hamburg, 27.7.64. Subject: Various brands prpvided manually with charcoal filters. Reference: Your letter" of ~@ July~ 1964. • The cigarettes submitted to us: Reval Hoth H~nd le Reyno Gold Dollar Krone 0rienta and Players Medium has been tested, with the following observations: Roth H~nd le: At the start of smoking, the tobacco taste was still quite marked, but as smoking proceeded this decreases and a detectable charcoal taste is experienced. No tobacco taste, but charcoal taste predominates. pla~ers Medium: No tobacco taste, but charcoal taste predominates. The cooling effect of menthol has disappeared. A slight menthol taste mixed with charcoal taste still from the first and second puff, but later only charcoal taste. No tobacco taste can be detected throughout. Gold Dollar: No tobacco taste, but charcoal taste predominates. Orients: The cigarette was completely neutral amd void; neither tobacco taste nor charcoal taste can be recognlsed. Copy to: In connectlou with thlsexuerimental series, it is worth noting that all clgarettes other than Roth E~ndle and Orients have a Charcoal taste, leading to the hypothesis that it is likely that a charcoal taste is more intensive- ly detectable from cigarettes which contain either only Virginia tobaccos or mainly Virginia tobaccos, compared with other cigarettes such as, e.g. black cigarettes (Roth H~ndle) and pure Oriental cigarettes (Orients). H. Fischer. Eerr Se!bmann, Herr Sottorf, Dr. Seehofer. O O~ O o Ls~

To: Dr. Seehofer Ealn Laboratory, Bahrenfeld Internal report from Eaw Tobacco Dept. Hamburg, 28.7.64 Subject: Charcoal filters on HB M~.xture and the components of the mixture The test on 7 different cigarette brands fitted manually with charcoal filters (see eva!uatio~ by Raw Tobacco Department reported o~ 27.7.64) caused us to separate EB mixture into its components and to manufacture cigarettes with charcoal filters therefrom, in order to establish how the various tobacco groups react towards the charcoal filter during smoking. The following cigarette specimens were prepared: I) Original HB mixture 2 ) ~ " " 3) HB stems . ) HB Bur ley Group 5) HB Virginia G~oup 6) EB Oriental Group without stems A smoke evaluation produced the following results: For I): No tobacco taste can be established any longer, but an intensive charcoal taste is experienced. For 2): As for I. For 5): Stem taste predominates, and some charcoal taste is only experienced durimg continued smoking but this intensifies as the cigarette burns down towards the end. For 4): For 5): For 6): The Bur!ey taste can still be readlly discerned at the start but it decreases fast as smoking is continued when the charcoal taste predominates.. As for I. No charcoal taste can be found during the first 2-3 puffs, and then some charcoal taste is discerned but this is not as marked as with 1-5. No tobacco taste is present. The cigarette is almost neutral. The best results for a suppression of the charcoal taste are therefore provided by the cigarette from the Oriental fraction the cigarette from the Burley fraction the cigarette from the stem fraction. H. Fischer Copy to: Herr Selbmann, Herr Sottorf. i. CD OW Cr~ ~O C~ ICD

File Note 318 Subject : Smoke evaluation on experimental charcoal filters. The experimental filters prepared in the laboratory with the use of various charcoal types for test purposes have been evaluated by us as follows with regard to taste: IT Rin~sdorff and Draser: Very marked undesirable "off taste" (charcoal taste) PittsburF: Still a marked charcoal taste, though better than the two varieties above. By far the best variety with regard to taste. The charcoal taste has been repressed to a large extent. Ther~ is reason to assume that when this charcoal type is used in conjunction with an appropriately -cased and flavoured mixture, no undesirable side taste will be experienced. It is important not to dlsresard the smell of smoke during an evaluation of charcoal filters. The smoke which is exhaled and also the main smoke escaping during the pauses between puffs through the ~ilter both stink in the case of the Ringsdorff, Drager and Pittsburg varieties. Ho undesirable effects in this respect are only experienced in the case of the Lurgi variety. E. Pfennig. Hamburg, 12 November 1964 Copy to: Herr Sottorf, Herr Selbmann, Main Laboratory. CD Cr~ ~.O CD CD J

-8- 4. Discussion 4.1 S~mnary of results The points mentioned below have to be remembered during any interpretation of the following Figures and Tables: The "chamber filters" and "bonded filters" made manually by the Filter Production Department largely consisted of charcoal. The acetate discs for sealing the filter were only 3 mm long so that the total draw resistance of the specimen filters only amounted to about 20 mm H20. The data obtained with the filters obtained by this method therefore mainly provide information on the charcoal ou its own and thus are essentially limited to changes in the gas phase. In practice, the retention effect of an acetate filter of appropriate length and draw resistance would have to be added. After taking into consideration the comparative evaluation of results from the chemical and biological tests, the Tables and curves lead to the following order of merit: i. Ringsdorff charcoal 2. Pittsburg charcoa! 3. Drager charcoal 4. Lurgi charcoal A few generally important points may be emphaslsed: All the 4 charcoal varieties seem to be more efficient than the Lark filter or the Filtrona Bonded Filter FF 561, from the point of their overall activity. There is no evidence of an appreciable difference between their suitability for a chamber filter or for a bonded filter. Their effect is controlled via the amount of charcoal employed. The activity lost due to the bonding agent in a bonded filter is compensated by approximately doubling the amount of substance. 1 J CD ~O Cr, CD :CD IO3 • ..

-9- i 4.2 Discussion of procedures and filter types. in the meantime, cigarette brands with a wide variety of char- coal filter constructions have appeared on the international : market. It is fundamentally possible to differentiate between four main possibilities for the arrangement of active charcoal I i~ a cigarette filter. The first of the possibilities consists in charging or dispers- ing fine active charcoal powder on paper filters. The absolute amounts of active charcoal which can be applied by this method ar~ relatively low, and are likely to be of the order of 30-50 mE/tip. The best known examples of brands in this class are Tareyton (USA), Tennyson (S~itzerland, Germany, Finland] and Carlton (USA). A second possibility consists in charging or dispersin~ fine active charcoal powder or even larger granules of active charcoal on white or black cellulose acetate. As a rule, the cellulose acetate is not in that case compounded with plasti- c!sets. The absolute amounts of active charcoal which can be a~plied by this method were initially very low, but at present amounts of I00 mg or more per tip have been achleved. Ezamo!es in this class include York (USA), Galaxy (USA!, Lucky StriKe Filter (USA) and Philip Morris Multifilter (USAJ. A third possibility consists in loosely filling active charcoal into a chamber formed between two ordinary filter pieces, eithez of cellulose acetate, e.g. Lark and Devon (USA) or of a paper filter, such as e.g. Duke of Durham (USA). The amount of char- coal which can be applied by thls method amounts to about 130 rag, The fourth method employs active charcoal granules in a double filter in which the charcoal grains have been more or less firmly with a bonding agent. A polyethylene or similar plastic product ~s usually employed as the bonding agent. The best known example in this class is Tempo (USA) as well as Eiggio (South Africa) and a special form of York (USA). The amount of charcoal which can thus be applied in this filter amounts to 200 mg and more. A!thou~h the opinion was first of all expressed that the ad- sorptlon efficiency of a charcoal filter inter alia depends on the arrangement of active charcoal in a filter, our present state of knowledge indicates that the adsorption capacity of a filter is largely a function of the amoun~ of charcoal. It m~Ast nevertheless be recognised that the arrangement of active charcoal in a cigarette filter is evidently of extreme import- ance from the point of view of the taste of smoke. According to the experience obtained to date, filters of the chamber type with loose granulates (the third possibility) affect the taste of smoke least. The remaining order of merit is charcoal granulate on tow (second possibility), followed by bonded charcoal filter (fourth possibility). Although the first method apparently affects the taste of smoke even less than the third, this method can nevertheless be dis- O re~arded during an evaluation because the amounts of active charcoal which can be applied by this procedure are much too low for this type of filter to be accorded special attention at the present time. O~ CD (D xO

- l0 - A general comparison of the procedures now Known and applied reveals that the chamber filters evidently offer most promise for future further development. This is because if sorptien additives other than active charcoal should become more important, a chamber filter could readily be filled wlth any other materials. This condition is not fulfilled directly for the other types of charcoal filter, either for the bonding ef charcoal granules on tow or for a bonding of charcoal granules to each other: in each of these cases, a special modification would have te be developed for each new adsorption medium: 4.3 Discussion of Patent and legal situation. Since in Germany, cigarettes as well as cigarette filters are subject to the Regulatlens ef the Food Act, it would be necessary to apply to the Federal Ministry of the Interior for the grant of an exemption permission or experimental permission for the application of active charcoal in cigarette filters prior to every case of introducing a cigarette brand with a charcoal filter. The above mentioned bonding agent polyethylene has already been detailed in the Tobacco Regulations, and no special application would have to be made for its use, but special permission would have to be sought for the application of any other bonding agent in any Intended bonded filter. If it should be intended to manufacture a previously known type of charcoal filter, according to a previously known process for the production of charcoal filters, the situation with regard to Patent Law is likely to be of secondary importance, since any problems encountered in this respect would primarily concern the manufacturers of filter machines. However, should the development of a novel filter type or the development of a novel process for tb~roducmlon of filters be envisaged, the patent situation would have to be very critically examined since a large series of older and more recent patent specifications concerning the problem of char- coal filters has been published. A llst of the patent specifications on this topic which have so far been discovered by us will be found in the Appendix. CD L~ 43D O J(ID

- ll- 5. Recommendations. From the chemical point of view, an active charcoal with the adsorption capacity of the Ringsdorff charcoal is absolutely recommended for processing in cigarette filters. Special interest shoul~ be paid to the form presented by the Lurgi charcoal, i.e. short moulded cylindrical rods, for physical and taste reasons. Appropriate steps have already bow been taken to solve the problem of the possible production of Ringsdorff charcoal in the Lurgi shape, it might be possible to prepare a novel optimum active charcoal product by such a method. A certain degree of preference should be accorded to the - chamber filter type in comparison with other ty~es of charcoal filters, in order to take account of future developments. This type of filter would be most readily modified for other fillings, e.g. silica gel, or for an activated or impregnated carrier material, should the emphasis of the discussion regarding adsorption by a filter be displaced in other directions, say towards oxides of nitrogerL, nitroaamines, formaldehyde, organic acids or the like. As far as the tobacco mixture is concerned which should be applied in cigarettes with charcoal filters, special importance undoubt- edly attaches to the tobaccos which have been "air cured~ within the widest sense of the term. A product prepared by the most careful attention to the above considerations will nevertheless undoubtedly still exhibit some "charcoal taste". We therefore do not think that a thorough casins and flavouring, included from the start in any planning, can be dlspensed with for a cigarette with a charcoal fil~er. These ~actors provide the final possibility of masking or overshadowing the residual cha.~coal taste which is bound to remain. p-. O O~ ~D O