House lawmakers are upping the pressure on the e-cigarette industry with two hearings looking to rein in vaping and assess its risk as an emerging public health threat.

The House Appropriations Committee and an Energy and Commerce subcommittee have called physicians, parent groups, public health officials and anti-smoking groups to testify Wednesday. The hearings are the latest in a recent wave of congressional scrutiny over the e-cigarette industry amid a teen vaping epidemic and an outbreak of a vaping-related lung disease that's killed at least 26 people across the U.S.

Public health officials are grappling with a surge in vaping among underaged teens, even as smoking rates have been falling for years. More than 25% of high school students said this year they use e-cigarettes, according to preliminary federal data. The mysterious lung illness has sickened nearly 1,300 people in all but one state. Most cases involve marijuana, though the outbreak has nonetheless heightened alarm around e-cigarettes.

CDC Principal Deputy Director Anne Schuchat will make her third congressional appearance over the past month at the appropriations panel hearing, titled "E-cigarettes: An Emerging Threat to Public Health." Schuchat will highlight preliminary findings from the CDC's annual survey showing that most teens who vape use flavored e-cigarettes, according to her written testimony.

Local and state governments are increasingly taking aim at flavored e-cigarettes, which are thought to attract kids to the tobacco products. A number of states, including Michigan, New York, Rhode Island and Washington, have passed emergency bans on them. The Trump administration is also readying its own plan to pull flavored e-cigarettes from shelves.

Flavors will likely play a key role in the Energy and Commerce subcommittee legislative hearing, titled "Legislation to Reverse the Youth Tobacco Epidemic." Committee Chairman Frank Pallone Jr. D-N.J, is co-sponsoring a bill that would ban flavored e-cigarettes, prohibit online sales of tobacco products and raise the smoking age to 21, among other restrictions.

Representatives from two public health groups — the American Academy of Pediatrics and Campaign for Tobacco-Free Kids — will testify in support of the legislation. In written testimony, they contend the bill would limit e-cigarettes' appeal and minors' access to the products.

"The legislation addresses the leading drivers of youth tobacco use and tobacco-related health disparities — the use of sweet flavors that appeal to children and contribute to their misunderstanding of the health risks of these products, the use of marketing and promotions designed to reach and appeal to kids, and easy access to tobacco products for our nation's young people," Campaign for Tobacco-Free Kids President Matthew Myers said in prepared testimony.

The American Academy of Pediatrics slams leading e-cigarette maker Juul in prepared testimony before the Energy and Commerce panel, saying the salts it uses in its vaping devices help deliver "dramatically higher levels" of nicotine to the brain than other products.

"Adolescents simply do not stand a chance," pediatrician Dr. Susanne E. Tanski said in prepared remarks on behalf of the group.

Outcry over e-cigarettes has angered adults who turn to vaping to help quit smoking, even though e-cigarettes haven't been reviewed or approved by the FDA as smoking cessation devices. On social media, some are using the hashtag #WeVapeWeVote to amplify their displeasure about government restrictions.

Each House panel has called a witness from the opposition. Boston University professor Michael Siegel will warn the House Energy and Commerce subcommittee of the unintended consequences that could accompany Pallone's bill, such as fueling a black market of shoddy unregulated products. Dr. Sally Satel, a resident scholar the American Enterprise Institute, will urge the Appropriations panel to preserve possible benefits for adult smokers.

"We must not allow the intense focus on teen use — warranted though it is — to divert almost all attention from the benefits of vaping for adult smokers who are dying at the rate of 480,000 per year from a terrible habit," Satel said in her written statement.

If passed, Pallone's bill, could weigh on the e-cigarette industry's profits. Pallone co-sponsored the bill with Rep. Donna Shalala, D-Fla., former President Bill Clinton's Health and Human Services secretary. The legislation is one of a number of e-cigarette bills Democrats have introduced this year.

The House Judiciary Committee on Wednesday will separately vote on a bill that would require companies to verify customers' ages when ordering e-cigarettes online and delivering them. The legislation would also subject e-cigarettes sold online to local tobacco taxes.

Rep. Raja Krishnamoorthi, D-Ill., has led an inquiry into Juul's advertising, including whether the company marketed to minors. Pallone in August launched a similar probe, requesting marketing materials from Juul, NJOY, Reynolds American, Fontem Ventures and Japan Tobacco International.