U.S. Sens. Ron Wyden and Jeff Merkley (D-Ore.) joined nine fellow Democratic senators today in demanding answers from Juul Labs, the leader in the rapidly growing market for electronic cigarettes.

Juul recently agreed to a large investment from Altria, the tobacco giant best known for manufacturing Marlboro cigarettes. The Democratic lawmakers want to know whether Juul is trying to get kids hooked on vaping and turning them into the kind of long-term consumers that makes tobacco a highly profitable business.

Today, the senators sent Juul a seven-page list of questions aimed at clarifying whether the company is complying with FDA guidelines on marketing to under-age vapers how the company plans to conduct business in the future.

"While JUUL has promised to address youth vaping through its modest voluntary efforts, by accepting $12.8 billion from Altria—a tobacco giant with such a disturbing record of deceptive marketing to hook children onto cigarettes—JUUL has lost what little remaining credibility the company had when it claimed to care about the public health," the senators wrote. "While you and your investors may be perfectly content with hooking an entire new generation of children on your tobacco products in order to increase your profit margins, we will not rest until your dangerous products are out of the hands of our nation's children."

Ted Kwong, a spokesman for JUUL said in a statement that the company is eager to provide answers to the senators.

"We agree that companies such as ours must step up with meaningful measures to limit access and appeal of vapor products to young people," Kwong said. "As part of our action plan deployed in November 2018 to keep JUUL products out of the hands of youth, we stopped the sale of certain flavored JUULpods to traditional retail stores, strengthened our retail compliance and secret shopper program, enhanced our online age-verification, exited our Facebook and Instagram accounts and are continuously working to remove inappropriate third-party social media content.

Kwong added that JUUL's relationship with Altria could reduce smoking.

"The Altria investment will help us switch adult smokers off of combustible cigarettes by helping us get our product in their hands," Kwong said. "We are directly connecting with adult smokers through a variety of initiatives including inserting information about JUUL products in cigarette packs."