Tuesday marks the first day of Chicago's e-cigarette ban, which outlaws smoking the vapor devices in indoor places.

The law, passed in January, prohibits lighting up in most public spots, such as bars and restaurants, and forces store owners to sell the cigarettes from behind a counter to stem access to those under the allowed smoking age.

The news comes just about a week after the Food and Drug Administration (FDA) issued a call for comment on a federal law that would limit marketing of e-cigarettes and ban them from being sold to minors.

"Tobacco remains the leading cause of death and disease in this country," said FDA commissioner Margaret A. Hamburg, M.D. in a press release. "This is an important moment for consumer protection and a significant proposal that if finalized as written would bring FDA oversight to many new tobacco products."

Critics of e-cigarettes describe them as a potential 'gateway' drug that could lead minors to using other drugs such as cocaine, heroin and marijuana. They're also not happy with marketing campaigns that seem to be aimed at youngsters or the fact that vendors are now selling flavored device options.

Those advocating bans and sales restrictions say it's necessary so not to undermine current tobacco laws on the books.

Yet advocates, mostly smokers trying to quit tobacco cigarettes, claim they aren't harmful to the public as cigarettes and shouldn't fall under the same rules and laws.

Chicago isn't the first city to ban e-cigarettes. New York enacted a similar law, placing e-cigarettes under its current public ban on tobacco smoking, late in 2013. New York enacted its smoking ban back in 2002.