Sept. 25 (Bloomberg) -- U.S. travelers will be allowed to start boarding planes tomorrow with liquids and gels bought inside airport security checkpoints as the U.S. eased rules triggered by a terror plot to blow up jetliners.

Passengers also will be able to bring travel-size containers of toothpaste, shampoo and other toiletries through checkpoints, the U.S. Homeland Security Department said today in Washington. The liquids and gels had been banned since Aug. 10 after U.K. authorities disrupted the plot.

``The total ban is no longer needed,'' Transportation Security Administration Director Kip Hawley said at a news conference. ``We are confident in our increased security measures throughout the airport.''

Governments are trying to reduce airline hassles that increased after the ban. Canada announced today it will adopt the new measures starting tomorrow, and the U.K. said last week it would let musical instruments back into passenger cabins and increase the size limits for carry-on luggage.

Groups representing the U.S. airline industry, travelers and airports welcomed the easing of the no-liquids policy. Carriers including Continental Airlines Inc., US Airways Group Inc. and JetBlue Airways Corp. had said tighter rules hurt their August unit revenue by driving off some business fliers.

``Security has always been a balance between safety and convenience, and it appears this time they're pointing a bit more toward convenience,'' said David Stempler, president of the Air Travelers Association in Potomac, Maryland.

Rule on Liquids

The new rules are still more restrictive than those in place before Aug. 10. Liquids carried through checkpoints must be in containers no larger than 3 ounces. All the containers must fit in one clear, quart-sized zip-top bag, which must be removed from carry-on luggage and X-rayed separately.

The U.S. doesn't plan further easing of the liquid-and-gel ban any time soon. It will be nine months to a year before the agency knows whether it can deploy baggage scanners sophisticated enough to detect liquid explosives, Hawley said.

``The screening machines being used in the first place are faulty and don't detect the things they need to,'' said Michael Greenberger, director of the Center for Health and Homeland Security at the University of Maryland in Baltimore. ``There's a lot of dollars being wasted on the current technology they're using.''

EU Action?

U.S. Homeland Security Deputy Secretary Michael Jackson said he expected that European Union countries may soon follow the loosening of the liquids ban. Baby formula, required medications and glucose treatments for diabetes already were exempt from the ban.

U.K. officials said last month that terrorists planned to carry liquid explosives onto jets flying between the U.K. and the U.S. and detonate them in flight. The authorities have charged 11 people with conspiracy to murder. The U.S. threat level for air travel remains at orange, or high risk of terrorist attacks.

Hawley said loosening the liquids ban frees the U.S. security agency to use more workers for detecting bombs at checkpoints and observing suspicious passengers throughout airports. ``We would rather put our effort there than enforce a ban on lip gloss,'' he said.

The agency also will do more random screening and identity inspections of secure-area employees, Hawley said. Because passengers will be able to buy liquids such as coffee and carry them on planes, the government wants to make sure no harmful substances are smuggled on board, he said.

Carry-On Bags

Hawley said the new approach may increase the amount of carry-on baggage, easing the strain on airlines' checked-luggage systems. The amount of checked baggage surged 20 percent after the liquids ban.

Airlines back the easing of the liquids ban because of the security agency's assessment and ``because it will reduce passenger inconvenience,'' James May, president of the Air Transport Association, the Washington-based trade group for U.S. carriers, said in a statement.

``We're supportive of whatever is necessary for security measures,'' said Nancy Gautier, spokeswoman for the Geneva-based Airports Council International. ``But most of the sales are located after airport security anyway, so it's already under tight control.''

Airports worldwide generate about half of their revenue from retail, including income from shops and food and beverage sales.

At Atlanta-based Paradies Shops, which operates more than 500 stores in 60 airports, the ban on liquids shifted sales away from items such as bottled water and souvenir hot sauce to products such as T-shirts, spokeswoman Bobbi Passavanti said.

``It's really good news for our customers,'' she said about the easing of the ban. ``We might see the resumption of the sales trends at our stores we saw before the rules came in August.''

To contact the reporter on this story: John Hughes in Washington at jhughes5@bloomberg.net

Last Updated: September 25, 2006 16:08 EDT