Table 3.

Examples of Patented Innovations to Reduce the Visibility of Cigarette Smoke

Site	Strategy and exemplar quotations:
Number of patents identified (n = 18)
Paper	Ultrafine particles in wrapping material: “In an embodiment, a wrapping material of the present invention comprises ultrafine particles distributed in a manner to provide substantially full coverage of the wrapping material by ultrafine particles....exploiting the sintering properties of ultrafine particles to form zones of reduced oxygen access and/or altered thermal properties; catalyzing reactions in the burning cigarette that modify the combustion process; exploiting the ability of ultrafine particles to alter combustion (e.g., in conjunction with water) and/or modifying the gross physical properties of the smoking articles (e.g. cigarettes) for example the ash structure and/or cigarette structure (e.g. cross-sectional shape, longitudinal shape).... cigarettes do not provide an undesirable off-taste and off-aroma to the mainstream and sidestream smoke generated thereby, and are capable of generating relatively low levels of visible sidestream smoke...” (Crooks, Sears, Cole, & Banerjee, 2004)
	Filler affecting visible sidestream smoke: “The invention relates to a cigarette paper having... low total filler content, 20% by weight of the paper or less, a proportion of the filler being a filler capable of effecting visible sidestream smoke reduction. The basis weight of the paper is about 30g m.sup.-2 or more. Smoking articles made with such papers provide a synergistic sidestream smoke component reduction when compared with control cigarettes. Papers according to the invention with the addition of various burn additives are also described.…” (Case & Stephenson, 2002)
	Non-combustible wrapper: “The invention relates to a smoking article having a high proportion of non-combustible, inorganic material and a relatively low level of visible sidestream. The smoking article includes a substantially non-combustible, wrapper which extends along the full length of the smoking material rod and enwraps a combustible fuel source and aerosol generator, both of which extend substantially along the length of the smoking material rod....” (Beven et al., 2003)
	Addition of calcium carbonate: “A wrapper paper for a smoking article, which permits decreasing an amount of visible sidestream smoke of tobacco, contains at least 30g/m2 of calcium carbonate and at least 3% by mass of a burn adjusting agent.” (Ishikawa, 2004)
	Oxygen storage and donor metal oxide oxidation catalyst and an essentially non-combustible particulate adjunct: “A low sidestream smoke cigarette comprises a conventional tobacco rod, and a combustible treatment paper having a sidestream smoke treatment composition. The treatment composition comprises in combination, an oxygen storage and donor metal oxide oxidation catalyst and an essentially non-combustible particulate adjunct for said catalyst. Improvements are made in the treatment composition and/or the addition of metal oxides or carbonates therto to improve ash characteristics.” (Snaidr, Becker, & Chapman, 2003)