"There is a widespread urban myth that glass or fiberglass is mixed into each tin to cause abrasion to the lip, resulting in higher and faster nicotine absorption, but at least in the case of snus, the appearance of glass-like particles may be due to the formation of salt crystals."
"There is a widespread urban myth that glass or fiberglass is mixed into each tin to cause abrasion to the lip, resulting in higher and faster nicotine absorption, but at least in the case of snus, the appearance of glass-like particles may be due to the formation of salt crystals."
http://en.wikipedia.org/wiki/Dipping_tobacco