Tennessee and 37 other states are asking the Food and Drug Administration to regulate e-cigarettes -- devices that dispense nicotine using vapor, not smoke.

A report released earlier this month from the Centers for Disease Control and Prevention showed e-cigarette use had doubled among teens from 2011 to 2012.

Tennessee Attorney General Bob Cooper and attorneys general from the other states signed a letter asking the FDA to regulate e-cigarettes as "tobacco products" under the Tobacco Control Act. There are no age restrictions that keep children from obtaining them, a news release from Cooper's office said.

"We are always concerned when a potentially dangerous product is being sold to the public without regulation," Cooper said in the release. "This is especially alarming when companies attract youth to addictive products through advertising."

The release said e-cigarette advertisers make the product look fun and inexpensive. TV commentator and former Playboy model Jenny McCarthy posed for one brand's campaign.

Read the letter here