SACRAMENTO, Calif., Aug 27 (Reuters) - The California State Senate on Thursday passed a bill to regulate electronic cigarettes as tobacco products, sending the measure to the Assembly where a similar bill died earlier this year.

The bill by State Senator Mark Leno, a Democrat from San Francisco, would ban the use of e-cigarettes, also known as vapor cigarettes or vapes, in the workplace, at schools and other places where cigarettes already are forbidden, and would require that they be sold in child-resistant packaging.

Sale of e-cigarettes to minors already is banned but the bill would require businesses wishing to sell them to obtain a license.

E-cigarettes generally contain nicotine, drawn into the lungs after it is heated in a flavored liquid. The vapor also contains some formaldehyde and other chemicals, according to Leno.

Electronic cigarette makers and distributors have said the devices are a safer alternative to smoking. But Leno, whose bill is backed by the American Cancer Society and numerous other public health organizations, said they are highly addictive and can serve as a gateway to tobacco dependence and regular smoking.

Earlier this year, California's former top public health official said electronic cigarettes can lead to nicotine poisoning among children and threaten the state's decades-long effort to reduce tobacco use.