【Street Stall (2015)】

The Street Stall (2015)head of the Food and Drug Administration has threatened to pull e-cigarettes out of U.S. markets entirely unless e-cig makers take greater measures to curb the youth's use of their products.

Speaking at a public hearing Friday, Scott Gottlieb, the FDA Commissioner, said he was "horrified" at the surge in rates of teen vaping, NBC reported. More than 3 million U.S. teens use e-cigarettes, an increase of 78 percent since 2011, according to recent CDC data.

"I still believe e-cigarettes present an opportunity for adult smokers to transition off cigarettes and onto nicotine delivery products that may not have the same level of risks," Gottlieb wrote in a tweet ahead of the hearing. "However, if the youth use continues to rise, the entire category will face an existential threat."

This Tweet is currently unavailable. It might be loading or has been removed.

During the hearing, Gottlieb reportedly called out Juul specifically in reference to e-cigarette companies own attempts to curb teen use. Juul has restricted the sales of flavored products and worked with social media companies to crack down on posts from underage Juul users.

Efforts like this aren't going far enough, according to the FDA, which has also enacted new policies to ban flavors it says were created to appeal to teens.

But Gottlieb's comments threatening to ban e-cigarettes entirely represent a dramatic escalation. If the FDA moved to ban e-cigarettes, it would upend what's become a multibillion-dollar business.

"It will be game over for these products until they can successfully traverse the regulatory process," Gottlieb said, per NBC.