This Thanksgiving, leftover stuffing and turkey drumsticks aren't all that will go into plastic bags.

Some 25 million passengers are expected in the nation's airports during the 12-day Thanksgiving travel period, the busiest travel time of the year. That means some 25 million baggies filled with liquids and gels under new carryon regulations imposed by the TSA.

Just don't get the leftovers mixed up with the carryons.

Thanksgiving will be the first major holiday since the Transportation Security Administration imposed new regulations that allow liquids and gels onto airliners only if they are in containers that are 3 ounces or less and in clear, 1-quart zip-top plastic bags.

The new rules are pushing toiletry makers to make more travel-sized items, said Marshal Cohen, chief analyst with The NPD Group Inc., a market research firm. That includes companies like Unilever, whose brands include Dove soap, and Procter & Gamble Co. (PG), which makes Pantene and other shampoos.

Roughly 10 percent of the industry now makes those sizes, said Cohen. He expects by the next holiday travel season that will reach 25 percent, driven by the new regulations.

"There are companies that are starting to recognize that this is something that is not going away," Cohen said. "Sometimes the difference in being bought and not being bought is the size of the packaging you offer."

The TSA's ruling in late September followed a six-week ban of carry-on gels and liquids on all planes, ordered on Aug. 10 after an alleged plot to bomb U.S.-bound jetliners was foiled.

Now the TSA is touting its 3-1-1 initiative, holding news conferences and urging travelers to remember they can have 3-ounce bottles or less, in a 1-quart-sized, clear, plastic, zip-top bag, and only one bag per passenger.

Dozens of airports, from big ones like Los Angeles International and Chicago's O'Hare, to regional ones in Paducah, Ky., and Knoxville, Tenn., are buying bags and giving them to travelers.

Other airports, such as the two major ones in Washington, D.C., have given out bags for several years for people to place jewelry and other metallic items into while going through security. The two Washington airports gave out larger bags for that purpose but recently switched to the 1-quart size, ordering more than 1 million bags, said Tara Hamilton, spokeswoman for the metro Washington Airports Authority

Phoenix Sky Harbor Airport started a similar effort in April 2004, handing out up to 10,000 bags a week, buying in bulk at a cost of 3 cents each, said spokeswoman Julie Rodriguez. Now with the new regulations, they're using 8,000 to 10,000 bags a day, she said.

"We were using them for one purpose and now we're using them for another," Rodriguez said.

Some airports have volunteers or, in the case of Raleigh-Durham International in North Carolina, high school students, pass out the bags to travelers, along with brochures about the new rules.

Representatives from Glad Products Co. will distribute 50,000 bags at the Dallas/Fort Worth airport over the holidays, said David Kellis, spokesman for the company, a division of Oakland, Calif.-based Clorox Co. The company is also working out details for donations with airport authorities in San Francisco and Boston, he said.

"Their concern was, 'We need to get out information to consumers in advance so there aren't bigger holdups in the security line,'" Kellis said.

Glad hasn't noticed an upswing in sales of its bags since the new TSA regulations went into effect, Kellis said, but the company figures more people might become aware of the new rules when they travel this season, meaning increased sales later.

The free giveaways, such as 1 million by Hefty, a division of Pactiv Corp., show companies are paying attention, though they certainly aren't obligated to keep supplying people with bags, said Marcia Mogelonsky, a senior analyst with Mintel International in Chicago.

The entire plastic bag market — which includes garbage bags to sandwich bags — was worth $763 million in 2003 — and private label brands, commonly sold under grocery store names, have a solid place at the top, she said. The top brand name is Ziploc, whose storage and freezer bags made up 14 percent of all sales last year, Mogelonsky said.

Considering that nearly all households have bags, brands like Ziploc, made by S.C. Johnson & Sons, based in Racine, Wis., could now link their products to the new regulations, by affixing stickers or signs in stores, she said.

Jan Waldbaun and her husband, Steve Morse, went through security at the Milwaukee airport this week after seeing the new regulations on television. Morse said they've had scissors and a sewing kit taken before, and now they know to put their toiletries — travel size, of course — in bags.

"I just went and bought a box of those and use them when I travel," Waldbaun said.