E-cigs are barely regulated. The few studies that have been performed indicate that the vapor from certain brands contains carcinogens, including formaldehyde, acetaldehyde, and acrolein, but e-cigs are so new and have so recently become popular that the laws and regulations are struggling to catch up. At the moment, the U.S. has banned the sale to minors, but courts have rejected the FDA's repeated attempts to have them classified as drugs (in the same category as nicotine patches). In the E.U., some countries, like Greece, have banned them outright. Some, like Britain, want them treated like medical devices, which would mean they would be more heavily regulated and only sold in pharmacies in some countries. The ruling will trickle down to the member countries within the next few years, as each country has to adjust its individual local and national laws.