Vaping, or the use of electronic cigarettes, has taken off in popularity due to it being billed as a safer alternative to smoking.

The difference between vaping and smoking, however, is becoming smaller, with a study released late last year claiming that e-cigarettes are not actually safer than smoking tobacco. The study found that e-cigarette vapor damages human cells through the same mechanisms that cause cancer.

An announcement by the United States Department of Transportation further thins the veil between vaping and smoking, with U.S. Transportation Secretary Anthony Foxx proclaiming that e-cigarettes are banned on commercial flights.

The ruling applies to all scheduled flights by both local and foreign carriers that transport passengers within, to and from the United States.

According to Foxx, the ruling will protect the passengers of commercial flights from unwanted exposure to e-cigarette aerosol, which occurs when the smoking alternative devices are used while onboard an aircraft. Vaping exposes passengers on a flight to e-cigarette aerosol without a means to avoid it, due to the enclosed space of the aircraft.

In addition, Foxx said that the Department of Transportation took the practical approach in eliminating any confusion between tobacco cigarettes and e-cigarettes by applying similar restrictions to both products.

Previously, passengers were not allowed to pack e-cigarettes inside their checked luggage. However, they were allowed to pack e-cigarettes inside their carry-on luggage, with the restriction that the devices would not be charged while onboard an airplane.

The previous ruling was vague in determining whether passengers were allowed to use e-cigarettes while on a flight. The final ruling released by the Department of Transportation clarifies its stance on the matter.

Echoing studies on e-cigarettes, the Department of Transportation noted the harmful chemicals included within e-cigarette aerosol, causing it to take a precautionary approach in banning vaping on commercial flights while further studies are ongoing to better understand the risks of the devices.

In addition to the ban of e-cigarettes on commercial flights, the Department of Transportation has banned the smoking of both tobacco cigarettes and e-cigarettes on charter flights of local and foreign air carriers that require a flight attendant as a member of the crew.