Texas is moving closer to raising the legal age to buy tobacco products from 18 to 21, with the state House of Representatives giving final approval to a bill Wednesday that all but ensures it will reach the governor's desk.

Unlike most states that have passed so-called Tobacco 21 legislation in recent years, though, the Texas law will have a catch: It won't apply to members of the military. The bill is one of several recent proposals across the country to raise the age of tobacco sales to 21 – a longtime goal for public health experts, though some of these measures have been criticized by anti-smoking advocates who say they may bend to special interests or are overly watered down.

The Texas House, which passed the measure 102-36 Tuesday, voted to send a slightly revised bill back to the Senate for final approval Wednesday. The upper chamber's version of the bill, which passed 20-11 last month, exempted only active duty military personnel from the age restriction, but the tweak is not expected to face serious opposition. The law will go into effect Sept. 1 if signed by Republican Gov. Greg Abbott.

"We've known for decades how harmful tobacco and nicotine are for our youth and children, and how teen smokers become the next generation of adults addicted to tobacco," Dr. John Carlo, CEO of Prism Health North Texas and chair of the Texas Public Health Coalition, said in a statement. "We now urge the Senate and Gov. Greg Abbott to protect our Texas youth from nicotine addiction, lower the threat of smoking-related diseases and early death, and reduce health care costs for everyone in Texas."

Tobacco use is the No. 1 cause of preventable death in Texas and across the U.S., and directly translates to $8.85 billion in health care spending annually in the state, according to the University of Texas MD Anderson Cancer Center. Federal data shows the share of high schoolers who used tobacco products surged nearly 40% nationwide between 2017 and 2018, from 19.6% to 27.1%.

Tobacco 21 policies seek to limit young people's access to cigarettes and vape products "by lowering the likelihood of youth being in the same social networks as those who can purchase tobacco legally," Dr. Douglas Curran, president of the Texas Medical Association, said during testimony before the state House Public Health Committee in March.

The Texas measure initially passed unanimously out of the House committee, but did not include the military exemption, the Texas Tribune reported last month. An amendment exempting active military personnel was added while the bill was under Senate consideration, and once back in the House, it was broadened to include anyone serving in the military, not just those on active duty.

The Senate can now approve the House amendments or appoint a conference committee to resolve the differences in the bills .

"If you're in the military, you're probably not going to high school," Republican Rep. John Zerwas, who authored the lower chamber's version of the bill, told the Dallas Morning News last month.

Earlier this week, Maryland Gov. Larry Hogan signed legislation raising the age of tobacco sales to 21, also with an exemption for members of the military, while Tobacco 21 laws in Maine and California don't apply to active duty personnel.

In January 2018, San Antonio became the first city in Texas to pass its own Tobacco 21 ordinance, with proponents there relying on the support of military-linked advocates to see the measure through. An estimated 1 in 8 people are associated with the military in the city of more than 1.5 million .

"It feels a little counterintuitive to think that someone will say, 'Oh, if you can fight for our country, you can get addicted to cigarettes,'" Colleen Bridger, San Antonio's top health official, told U.S. News in February .

Also key to Bridger's success helping to pass the ordinance in San Antonio: The rapid rise in e-cigarette use among teens in recent years. About a third of Texas high schoolers and 11.5% of middle schoolers had tried e-cigarettes, according to a January report from the Texas Department of Health and Human Services .

The surge in youth e-cigarette use has been a catalyst for Tobacco 21 advocates across the country, including in Texas, where state lawmakers had previously rejected similar proposals to raise the age of purchase.

Support for Tobacco 21 policies also has come from an unlikely source: Big Tobacco. Altria, the parent company of Philip Morris USA, and Juul Labs, maker of the popular e-cigarette device Juul, both lobbied Texas lawmakers to raise the age for tobacco sales this year, according to the Dallas Morning News , and reportedly have poured millions of dollars into ads supporting Tobacco 21 legislation elsewhere.

Yet some anti-smoking advocates worry that support may come at a cost, with potential loopholes or workarounds tucked into some of the bills that could allow tobacco companies to head off further regulation. One Tobacco 21 bill that passed in Arkansas last week, for example, also prevents localities from enacting further restrictions on tobacco products, such as limiting e-cigarette flavors.

Another amendment to the Texas bill this week, meanwhile, would preempt local governments from further raising the age to buy tobacco products. A separate bill that would have imposed a 10% state retail excise tax on e-cigarette and vape products effectively died late last week, the Dallas Morning News reported , after Abbott and tobacco lobbyists pushed for last-minute changes to the bill's language .

Debate over Tobacco 21 laws at the state and local levels may soon be moot: A bipartisan group of U.S. senators introduced federal Tobacco 21 legislation late last month that is supported by the Campaign for Tobacco-Free Kids. Senate Majority Leader Mitch McConnell also has said raising the legal age to purchase tobacco nationally is a "top priority," and that he plans to introduce his own Tobacco 21 bill that may also exempt military personnel .

Matthew Myers, president of the Campaign for Tobacco-Free Kids, said in a statement last month that any federal Tobacco 21 legislation should be "free of special interest provisions that benefit the industry."