Tobaccos are cured in a manner so as to provide tobaccos having extremely
low tobacco specific nitrosamine (TSNA) contents. Harvested Virginia
tobacco is subjected to flue-curing so as to provide flue-cured tobacco.
During the curing processing steps, contact of the tobacco with nitric
oxide gases, such as those produced as combustion products of propane
burning heating units, is avoided. Tobacco in curing barns is not
subjected to direct-fire curing techniques, but rather, heat for tobacco
curing can be provided by heat exchange or electrical heating methods.