No butts about it, San Francisco is set to become the nation's second-largest city to make it illegal for young adults to buy cigarettes.

FOX's Tom Graham reports:

Starting June 1, smokers will have to be 21-years-old if they want to buy cigarettes or other tobacco products in San Francisco. That also includes e-cigarettes, despite the devices lack of any actual tobacco.

San Francisco joins New York City, Boston, and Hawaii in raising the age. Critics argue 18-years-old is the legal age for voting or serving in the military and say smoking should be no different.

Supporters counter the new rules could discourage young people from picking up a life-long habit.

Tom Graham, FOX News.