The DoT says that it made the change to protect passengers from the potentially harmful aerosol fumes, particularly young children, the elderly and folks with respiratory issues. While the agency admits that the full extent of the risks have yet to be determined, it decided "a precautionary approach" was the best course of action.

"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," said US Transportation Secretary Anthony Foxx. "The Department took a practical approach to eliminate any confusion between tobacco cigarettes and e-cigarettes by applying the same restrictions to both."

Back in October, the Department of Transportation's hazardous materials arm prohibited battery-powered smoking devices in checked bags and charging those gadgets while on board. In addition to commercial travel, today's ban also extends to any charter aircraft where a flight attendant is a member of the crew.