WASHINGTON - A Senate committee on Tuesday approved the nomination of Texas radiation oncologist Stephen Hahn to be head of the Food and Drug Administration, which is currently embroiled in a high-stakes debate over how to regulate e-cigarettes and curb youth vaping.

The vote by the Health, Education, Labor and Pensions Committee was 18 to 5. If approved by the Senate, Hahn, a top official at MD Anderson Cancer Center in Houston, will be the fourth head of the FDA in less than a year.

Committee Chairman Lamar Alexander, R-Tenn., said before the vote that Hahn is "exactly the type of nominee" that should lead the FDA, citing his management and research experience.

But Sen. Patty Murray, D-Wash., the panel's ranking Democrat, voted against Hahn, saying during his confirmation hearing last month he had "refused to commit to implementing a strong policy to clear nontobacco e-cigarettes" from the market - a step President Donald Trump promised in September but has not finalized. Other Democrats split, with some voting for Hahn's confirmation and others voting against him.

The timing of the full Senate vote isn't known but Alexander has said he hoped Hahn would be confirmed by the end of the year.

During his confirmation hearing, Hahn ducked questions from senators unhappy about the Trump administration's failure to prohibit flavored e-cigarettes. Hahn said he was alarmed by 2019 data showing that almost 28% of high schoolers have vaped in the last 30 days, but said he didn't want to prejudge the administration's e-cigarette policy because he hasn't been involved in developing it. He vowed to use "science and data" to address that issue and others.

The Washington Post reported last month that Trump balked at finalizing the ban after vape shop owners protested it would cause job losses in their industry and erode support for his reelection. In a recent meeting with health groups, vaping advocates and tobacco executives at the White House, Trump expressed concern that a flavor ban could result in an increase in counterfeit products.

In a letter Monday, 28 members of Congress asked Trump to remove flavored e-cigarettes from the market until they are cleared by the FDA. Vaping advocates have argued that a flavor ban would hurt adults using e-cigarettes to quit smoking and that youth use should be reduced in other ways, such as by restricting where the products are sold.

Hahn oversees clinical care at MD Anderson. Previously, he served as chief operating officer of the hospital, and has been praised for helping engineer its financial turnaround. He also worked at the National Cancer Institute and the University of Pennsylvania.

Dozens of medical, patient and research groups on Monday urged his quick confirmation, saying the agency needs a permanent commissioner. But a leading tobacco-control group, Campaign for Tobacco-Free Kids, said Hahn shouldn't be confirmed until the administration issues a vaping policy.

The Trump administration’s first FDA head, Scott Gottlieb, stepped down in April and was replaced by acting commissioner Norman “Ned” Sharpless. Last month, Sharpless returned to his previous post as director of the National Cancer Institute, and Brett Giroir, a top official at the Department of Health and Human Services, succeeded him as acting FDA commissioner.