WASHINGTON - After decades of controversy, the Food and Drug Administration approved the first over-the-counter HIV test Tuesday, allowing people to test themselves in private at home and get preliminary results in less than 30 minutes.

The availability of an HIV test as easy to use as a home-pregnancy kit marks yet another step in the normalization of a disease that was once seen as a mark of shame and a death sentence.

"Knowing your status is an important factor in the effort to prevent the spread of HIV," said Dr. Karen Midthun, director of the FDA's Center for Biologics Evaluation and Research. "The availability of a home-use HIV test kit provides another option for individuals to get tested so that they can seek medical care, if appropriate."

Dr. Anthony Fauci, a longtime AIDS researcher who heads the National Institute of Allergy and Infectious Diseases, called the new test a "positive step forward" and one that could help bring the 30-year-old epidemic under control.

The test, manufactured by OraSure, already had been approved for medical clinics. The new at-home test, called OraQuick, will be sold in supermarkets and pharmacies beginning in October.

Tests for the human immunodeficiency virus, which causes AIDS, have become increasingly simpler and quicker to use since their introduction in the 1980s. In 2002, the FDA approved the first on-the-spot tests for clinics. In 2005, the FDA began exploring the possibility of approving a home test.

The FDA stressed that any results from a self-administered test, which works by detecting antibodies in a swab from the gums, should not be considered final.

In trials, the test failed to detect HIV in one in every 12 patients known to be infected, and returned false positives in 1 in 5,000 cases. Anyone receiving a positive result should follow up with a medical provider, the agency said.

In May, an FDA advisory panel unanimously recommended that the test be approved, saying the benefits outweighed the risks. One concern has been that people who learn they are infected may not have immediate access to counseling or support. Concern had been raised that a positive reading could prompt negative consequences ranging all the way up to suicide.

But Mark Harrington, policy director for the Treatment Action Group, an AIDS advocacy organization, said that he thought such fears were "a thing of the past" now that it is clear that early treatment saves lives. "Any tool that speeds up diagnosis is really needed," he said.

The agency said it hopes the new tests will reach people who are currently not getting tested, which, in turn, could lead to early treatment and reduce the transmission rate of the virus.

Previously, the FDA had approved an HIV home test, but the samples had to be sent to a laboratory for analysis.

The federal Centers for Disease Control and Prevention estimates that of the 1.2 million people in the United States with HIV, one in five is not aware of the infection. And it says that a disproportionate number of the 50,000 new cases of HIV each year are linked to people who have not been tested.

OraSure has not said how much the test will cost, only that it will be more than the $17.50 cost of the professional kit.

Kevin Frost, the chief executive of the AIDS research group amfAR, said although he thinks home testing is a good idea, a high price tag could put it beyond the reach of those who need it most.

"If the people who go out and pay for this test end up being sorority girls who had a one-night stand and worry if they're infected, that's not going to be a net positive," he said.

Doug Michels, president of OraSure, acknowledged that pricing is a "fine balance."

Michels said OraSure's research showed that the vast majority of people receiving a positive result said they would seek medical advice. The FDA also required OraSure to run a call center to support users of the test. Michels said trained counselors would answer the calls.

Because the FDA approved the test only for people age 17 and older, retail stores may ask for identification.

The New York Times contributed to this report.