An electronic tobacco device may now hit the US market after getting a green light from the US Food and Drug Administration, the agency announced Tuesday.

The agency made clear it has not deemed the device — Philip Morris International’s IQOS “tobacco heating system” — to be safe. And its decision to permit sales is not tantamount to FDA approval.

IQOS already is sold internationally and the company says nearly “6 million smokers have already switched to IQOS in the four years since it was first launched, with more than half of them in Japan. The new devices are designed to help accelerate the world’s conversion to a smoke-free future.”

The device is not an e-cigarette or vape like the ones that have surged in popularity among middle and high school students. Rather, it’s a noncombustible device that heats, without burning, “tobacco-filled sticks wrapped in paper to generate a nicotine-containing aerosol,” the FDA said.

The agency said the move followed “a rigorous science-based review,” after which it decided the product may have public health merit in part because the device contains “fewer toxic chemicals than cigarette smoke, and many of the toxins identified are present at lower levels than in cigarette smoke.”

“Ensuring new tobacco products undergo a robust premarket evaluation by the FDA is a critical part of our mission to protect the public, particularly youth, and to reduce tobacco-related disease and death,” Mitch Zeller, director of the FDA’s Center for Tobacco Products, said in a statement Tuesday.

However, the decision raised eyebrows among some public health advocates.

Harold Wimmer, president and CEO of the American Lung Association, said in a statement that he’s “deeply concerned” about the product’s potential health impacts.

“The Lung Association urges the FDA to carefully monitor how this product is actually being used — and by whom,” Wimmer said. “FDA must take steps to protect youth from beginning a tobacco addiction with this product.”