The perspective of potential regulatory ceilings on smoke deliveries in the future increase the need to assess the influence of tobacco blend components on smoke deliveries, more particularly the influence of papermaking reconstituted tobacco leaf (RTL), expanded stem (CRES) and expanded lamina (EL).

The effect of papermaking tobacco reconstitution on smoke yields has been assessed with respective contribution of the fibrous and the soluble fractions.

In the ISO smoking regime, and when comparing RTL to the tobacco blend used as feedstock for reconstitution, reductions up to 25% are observed for tar, tar/puff, benzene, nicotine, hydrogen cyanide (HCN), butadiene, toluene, phenols except catechol, carbonyls except formaldehyde. Reduction of ammonia, isoprene, styrene, aromatic amines, poly aromatic hydrocarbons (PAHs), semi volatiles are specific and superior to 40%.

The main precursors of carbon monoxide (CO), aldehydes, volatiles, ammonia, HCN, PAHs are in the fibre part. For other some constituents analysed, the precursors are present both in fibres and solubles (e.g. nitrogen oxide, phenol), or mostly in solubles (e.g. hydroquinone, 1-aminonaphthalene, 4-aminobiphenyl). On the other hand, the effect of blend components (CRES, RTL, EL) level (0-20%) has been tested through a design of experiment (simplex centroid matrix). Smoke deliveries were measured with the Health Canada Intense (HCI) smoking regime. Models were validated at 95% of confidence for puff number, CO, NO, NOx, ammonia, certain aldehydes and para-cresol and 4-aminobiphenyl. All three components decreased ammonia, aromatic amines, some phenols and PAHs. EL was the most effective to reduce phenols whereas RTL was the most effective for PAHs. The other smoke constituents are more or less stable except formaldehyde.

In conclusion, a majority of smoke constituent precursors are insoluble and reside in the fibrous insoluble portion of tobacco. In addition, the proportions of expanded lamina, expanded stems and reconstituted tobacco will influence smoke deliveries, contributing to reducing some of them, in particular RTL aromatic amines, phenols and PAHs.