Electronic cigarettes have been banned from commercial flights, the U.S. Department of Transportation announced Wednesday.

The new rule -- meant to protect passengers from exposure to harmful chemicals -- applies to flights into and out of the U.S., and to domestic and international carriers, the Washington Post reported.

Traditional cigarettes have long been banned on U.S. flights.

The new regulation "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 in a statement, the Post reported.