WASHINGTON — For the first time, U.S. health regulators have judged a type of smokeless tobacco to be less harmful than cigarettes, a decision that could open the door to other less risky options for smokers.

The milestone announcement on Tuesday makes Swedish Match tobacco pouches the first so-called reduced-risk tobacco product ever sanctioned by the Food and Drug Administration.

FDA regulators stressed that their decision does not mean the pouches are safe, just less harmful, and that all tobacco products pose risks. The pouches will still bear mandatory government warnings that they can cause mouth cancer, gum disease and tooth loss.

But the company will be able to advertise its tobacco pouches as posing a lower risk of lung cancer, bronchitis, heart disease and other diseases than cigarettes.

The pouches of ground tobacco, called snus — Swedish for snuff and pronounced "snoose" — have been popular in Scandinavian countries for decades but are a tiny part of the U.S. tobacco market.

Users stick the teabag-like pouches between their cheek and gum to absorb nicotine. Unlike regular chewing tobacco, the liquid from snus is generally swallowed, rather than spit out. Chewing tobacco is fermented; snus goes through a steamed pasteurization process.

FDA acting commissioner Ned Sharpless said the agency based its decision on long-term, population-level data showing lower levels of lung cancer, emphysema and other smoking-related disease with the use of snus.

Sharpless added that the agency will closely monitor Swedish Match's marketing efforts to ensure they target adult tobacco users.

"Anyone who does not currently use tobacco products, especially youth, should refrain from doing so," he said in a statement.

Stockholm-based Swedish Match sells its snus under the brand name, General, in mint, wintergreen and other flavors. They compete against pouches from rivals Altria and R.J. Reynolds. But pouches account for just 5% of the $9.1 billion-dollar U.S. market for chew and other smokeless tobacco products, according to Euromonitor market research firm.

And public health experts questioned whether U.S. smokers would be willing to switch to the niche product.

"Snus products have a bit of a challenge" among smokers who are used to inhaling their nicotine, said Vaughan Rees, director of Harvard University's Center for Global Tobacco Control.

The U.S. smoking rate has fallen to an all-time low of 14% of adults, or roughly 34 million Americans. But smoking remains the leading cause of preventable disease and death in the U.S., responsible for some 480,000 deaths annually.

The FDA's decision has been closely watched by both public health experts and tobacco companies.

Public health experts have long hoped that alternatives like the pouches could benefit Americans who are unable or unwilling to quit cigarettes and other traditional tobacco products. Tobacco companies are looking for new products to sell as they face declining cigarette demand due to tax increases, health concerns, smoking bans and social stigma.

The FDA itself also has much at stake in the review of snus and similar tobacco alternatives.

Congress gave the FDA the power to regulate key aspects of the tobacco industry in 2009, including designating new tobacco products as "modified risk," compared with traditional cigarettes, chew and other products.

But until Tuesday, the FDA had never granted permission for any company to make such claims for its products.

The FDA is reviewing several other products vying for "reduced risk" status, including a heat-not-burn cigarette alternative made by Philip Morris International. While electronic cigarettes are generally considered less harmful than the tobacco-and-paper variety, they have not been scientifically reviewed as posing a lower risk.