Keep in mind these requirements are distinct; you may go well over the 4,500 hours but still not meet the duration requirement if those hours were not spread over a three-year period. For example, assume you worked on two projects at the same time, over a two-year period.
Nicotine is the main ingredient of concern in smokeless tobacco. It is estimated that a normal, 30-minute dip of smokeless tobacco delivers the same amount of nicotine as 3-4 cigarettes. Nicotine affects the brain and central nervous system and changes neurotransmitters levels regulating mood, learning, alertness, and ability to concentrate.
Other Risks. 1  Using smokeless tobacco increases the risk for death from heart disease and stroke.1,3. 2  Smokeless tobacco can cause nicotine poisoning in children.4. 3  Additional research is needed to examine long-term effects of newer smokeless tobacco products, such as dissolvables and U.S. snus.