Abstract
The major components of 70 brands of smokeless tobacco products (STPs) from Sweden and the US were determined to provide greater understanding of the general chemical composition of these products. Various styles of STPs were examined: loose and portion snus from Sweden, and chewing tobacco, dry snuff, moist snuff, hard pellet, soft pellet and plug from the US. The components analysed were major STP components such as water, nicotine, sugars, humectants, sodium ions, chloride ions and ash. The relative quantities of the components varied significantly between different styles of STP. The major component of moist snuff and Swedish loose snus is water. With Swedish portion snus water and pouch material comprise more than half of the product mass; with chewing tobaccos water and sugars comprise around 60% of the products. With these STPs, tobacco was a minor component (30-35%) of the product mass. By way of contrast, tobacco comprised the majority (around 70-90%) of the product mass with dry snuff, hard pellet and soft pellet products. Additives such as sugars, propylene glycol, glycerol, and sodium chloride comprised up to around 12% of the STPs, except for plug and chewing tobaccos where sugars comprised 15-30% by mass of the STP on average. Significant disagreements were found amongst alternative methods of determining water/moisture content for STPs. In particular the oven method, commonly used to determine moisture in tobacco, gave significantly higher values than the Karl Fischer water method when propylene glycol was present. Smaller but similar differences were found using the Near-Infrared method. Choice of measurement technique has important consequences for accuracy of toxicant levels when reporting on a dry-weight basis, a commonly used parameter in smokeless tobacco research and emerging regulatory standards. Conversion to a DWB was also found to produce a preferential bias between and within different STP categories in favour of drier products. These data provide greater understanding of differences in the compositions of contemporary smokeless tobacco products, and demonstrate challenges associated with conversion of actual product contents to dry weight basis values.