A total ban on such products, instituted after a plot to bomb jets flying into the United States was foiled, is no longer needed, said Transportation Security Administration chief Kip Hawley.
"We now know enough to say that a total ban is no longer needed from a security point of view," Hawley told a news conference at Reagan National Airport.
He said that most liquids and gels that air travelers purchase in secure areas of airports will now be allowed on planes. He called the new procedures a "common sense" approach that would maintain a high level of security at airports but ease conditions for passengers.
That means that after passengers go through airport security checkpoints, they can purchase liquids at airport stores and take them onto their planes.
But critics like aviation analyst Michael Boyd says the Transportation Security Administration is years late in developing high-tech scanners, which can tell the difference between a liquid explosive and bottle of water, reports CBS News correspondent Bob Orr.
"Now they're saying they're looking into explosive detection for liquids," Boyd says. "That's something that should have been done by the afternoon of 9/11, if not long before."
The overarching ban on most liquids remains because the threat remains, reports Orr. Officials say the threat brought into the public consciousness by the U.K. terror plot has not been eliminated. Furthermore technology that is able to detect liquid explosives and components for bombs is not yet widely available, Orr notes.
New procedures also were announced for toiletries and products like lip gloss and hand lotion that passengers bring to the airport. Previously, those liquids have been confiscated at security checkpoints. Now, these products will be limited to 3-ounce sizes and must fit in a clear, one-quart-size plastic bag. The bags will be screened and returned if they are cleared.
The new security regimen is for an indefinite period and will take effect Tuesday morning.
Tougher airport screening procedures were put in place in August after British police broke up a terrorist plot to assemble and detonate bombs using liquid explosives on airliners crossing the Atlantic Ocean from Britain to the United States.
At the time, the Homeland Security Department briefly raised the threat level to "red," the highest level, for flights bound to the United States from Britain. All other flights were at "orange" and will remain at orange, the second-highest level, for now.
"Obviously, there's been a lot of unhappiness," said Richard Marchi, senior adviser to the Airports Council International, an airport trade group. "They're right to find a way to ease the burden and maintain a reasonable level of security."
In Washington, Orr asked Department of Homeland Security Michael Jackson if the United States was behind in dealing with the latest security threat.
"Whenever we're not able to crush a threat, I would say we're behind it," he said. "But we are working it and we are aggressively putting in place measures to mitigate it, of the sort that we have today."