From Connolly (2001)
Swisher (maker of Kayak): Silver Creek Total TSNA: 127.9
Conwood: Kodiak Total TSNA: 16.6
Swedish Match: Timber Wolf Total TSNA: 7.5
US Tobacco: Copenhagen Total TSNA: 41.1
US Tobacco: Skoal Total TSNA: 64.0
In recent years, the Swedish Match Company has developed a new method for manufacturing oral snuff that uses select blends of tobacco as well as a new processing method.
Instead of the dark fire-cured tobacco commonly used in US snuff, Swedish Match uses tobacco with a low nitrate content, which itself reduces TSNA levels. In addition, the tobacco is processed in a heated closed system that resembles pasteurization of milk, which eliminates bacteria that may be indirectly responsible for the formation of the nitrosamines.
The company also encourages retailers to refrigerate packages to prevent the formation of TSNA during storage.
Here you will find some more recent information.
http://dipoholic.2474u.de/scenihr_o_009.pdf