A law was passed by the city council on December 19 and signed by former mayor Michael Bloomberg.
It extends an already strict ban on tobacco smoking in public places in the metropolis, where even some residential buildings do not allow tenants to light up.
In a further unprecedented move for a major US city, retailers as of May 18 will no longer be allowed to sell tobacco products or e-cigarettes to anyone under 21.
Restrictions on the use of the battery powered devices in most indoor public places in Chicago also went into force Tuesday.
Also Read
With regulation varying from state to state, federal US regulators last week proposed the first restrictions on the booming USD 2 billion e-cigarette market.
The new rules would bring e-cigarettes under many of the same rules that already apply to traditional cigarettes, including requiring sellers to enforce a minimum age restriction on those who wish to buy the products.