The first step was to shove the wick back in
Homa DM, Neff LJ, King BA, Caraballo RS, Bunnell RE, Babb SD, et al
Nicotine is an addictive chemical. Packages too small to accommodate standard warnings may qualify for alternative labeling under specific FDA guidelines
In lab experiments, the researchers looked at what happened when cells that line the bronchi (the main airways from the trachea to the lungs) were exposed to flavoring chemicals, such as vanillin and ethyl-vanillin (responsible for vanilla and other sweet flavors), benzaldehyde (berry or fruit flavor) and cinnamaldehyde (cinnamon flavor)
IRB: Ethics Human Res
When it happens quickly enough, the expansion will apply pressure on the outermost layer of tobacco, thus causing the wrapper to split