A woman exhales vapor from an electronic cigarette at The Vapor Spot vapor bar in Los Angeles, California March 4, 2014. REUTERS/Mario Anzuoni

WASHINGTON (Reuters) - The U.S. Transportation Department announced on Wednesday it has banned the use of electronic cigarettes on commercial flights.

The rule applies to all scheduled flights by U.S. and foreign carriers involving transportation in, to and from the United States, the department said in a statement.

“This final rule is important because it protects airline passengers from unwanted exposure to aerosol fumes that occur when electronic cigarettes are used onboard airplanes,” Transportation Secretary Anthony Foxx said.

The Transportation Department said it took the action to eliminate any confusion over whether its existing ban on smoking on flights includes electronic cigarettes.

The Obama administration first began considering a ban in 2010 and proposed the ban in September 2011. The effort to explicitly ban e cigarettes was backed by major airline, pilot, flight attendant and public health organizations.

Congress banned all smoking on airline flights in 2000, and no U.S. airline allows electronic cigarette use. But the Transportation Department said some charter flights may have allowed the practice.

The department said the airline industry should not be able “to adopt its own standards with respect to the inclusion of electronic cigarettes within the prohibition on smoking.”

The regulation said: “We recognize that the industry has generally banned the use of electronic cigarettes on flights,” but added that “we believe that without a clear, uniform regulation, some carriers may feel free to adopt policies that allow the use of e cigarettes onboard aircraft.”