California would ban the use of electronic cigarettes in public places and ramp up enforcement against selling them to minors under a bill introduced in the legislature on Monday.

There is growing concern about the health risks from e-cigarettes, also known as vapor cigarettes or vapes, which are not lit or smoked like their old-fashioned counterparts, but do generally release nicotine in a heated liquid.

"Whether you get people hooked on e-cigarettes or regular cigarettes, it’s nicotine addiction and it kills," Democratic state Senator Mark Leno, who introduced the bill, said in a telephone interview. "We're going to see hundreds of thousands of family members and friends die from e-cigarette use just like we did from traditional tobacco use."

The bill would add e-cigarettes to the list of tobacco products regulated in the state, which already forbids smoking in workplaces, restaurants, bars and other places. It would also ramp up penalties for selling e-cigarettes, which come in such flavors as bubble gum and chocolate, to minors.

California would be the fourth U.S. state to treat them like regular cigarettes, and the 23rd to regulate e-cigarettes in some way. In California, the most populous U.S. state, 122 cities and counties have banned the use of e-cigarettes in certain public places.

Second-hand e-cigarette emissions contain cancer-causing chemicals, and could put children and others at risk if they are in proximity to users, said Kimberly Amazeen, vice president of public policy and advocacy for the American Lung Association in California.

The bill was criticized Monday by a group calling itself the American Vaping Association, which said it would harm smokers who are trying to quit by switching to e-cigarettes, which are marketed as a safer alternative to the combustible kind because they do not flood the lungs with smoke.

"California smokers deserve truthful information about smoke-free alternatives, not hype and conjecture designed to scare them away from attempting to quit with these innovative technology products," Gregory Conley, president of the American Vaping Association, said in a press release.

But Leno, whose bill is backed by the American Cancer Society, the American Heart Association and the American Lung Association, said the vapor released by the e-cigarettes contains carcinogens, and the nicotine in them is addictive.