KANSAS CITY, Mo. — Teresa Edwards has Purell dispensers throughout her house in Overland Park, Kan. She makes her two sons slather on the gel whenever they get home from school.

She would have made them wear the face masks she bought, if the things had fit properly. Now she’s shopping for child-size versions.

“I was and I still am freaked out by swine flu,” Edwards said.

So are millions of other people. They’re buying up face masks and sanitizing hand gels, hoping to stave off the H1N1 flu virus.

Demand from consumers and health care providers is creating nationwide shortages of these products and raising concerns that people may be putting too much faith in some flu countermeasures.

The Food and Drug Administration recently warned consumers to use extreme care when buying any products online that claim to prevent or treat swine flu.

“I think a lot of people want to feel like they’re doing something to protect their family and themselves. It may give them a false sense of security,” said Shawn Mueller, infection prevention and control manager at University of Kansas Hospital. She recommends such basic measures as covering coughs and sneezes, washing hands frequently and staying home when you’re ill.

Hand sanitizers are a good bet, Mueller said. They can kill flu viruses and make a good substitute for hand washing.

But the kinds of masks often used by the general public are only effective at stopping the sneezes of someone who is already sick. They are unlikely to keep people wearing them from catching the flu, she said. “A normal, walking-around human doesn’t need one,” Mueller said.

Flying off the shelves

Effective or not, swine flu avoidance measures have spread as rapidly as the virus.

Drugstores have moved their mask displays to prominent end-of-the-aisle positions. Discount stores such as Target are advertising masks and hand sanitizers among their “flu essentials.”

Hospitals are placing hand gel dispensers in their lobbies for visitors who come to see vulnerable patients. Doctors are handing out masks in waiting rooms. The U.S. Army has even started issuing hand gel to new recruits in basic training, olive-drab bottles that fit neatly into a shoulder pocket.

Edwards’ younger son, Anthony, 6, has asthma and allergies that make him vulnerable to flu and other respiratory infections. “Any little virus he gets turns into pneumonia overnight,” she said.

So Anthony and his older brother, Jeramieh, 9, are getting a lot of experience with hand gel dispensers.

Edwards went shopping for masks after eight of Jeramieh’s classmates were out sick recently.

“If he picks up anything, he’ll bring it home to Anthony. It’s too much of a risk,” she said.

Hand sanitizer sales have been tracking upward along with the nation’s growing anxiety about swine flu.

People bought more than $129 million worth in the year ending Oct. 4. That is 29 percent more than the year before, according to Information Resources Inc., a Chicago market research firm that follows most mass merchandise outlets, except Wal-Mart.

Recently, sales have skyrocketed. In September alone, spending on hand sanitizers was 177 percent higher than a year earlier. That is putting a strain on supply.

“Despite making huge investments to increase our capacity — running our plants 24/7 and increasing our staff — we are unable to keep up with the unprecedented demand,” Mark Lerner, the president of Gojo Industries, which manufactures Purell for hospitals and other institutions, said in a recent statement.

Behind the mask

Some kinds of masks also are in short supply.

It is still possible to get surgical masks, the kind of lightweight, inexpensive masks many people buy. If you have the flu, wearing one of these masks will help protect your family from your coughs and sneezes.

Doctors’ offices and emergency rooms may ask you to put one on if you arrive with flu symptoms.

“If I were ill and the doctor suspects I have influenza, that would be an appropriate time for me to wear a mask,” said Mueller of KU Hospital. “It’s to protect others from me.”

But these masks generally are too porous and their edges too leaky to offer real protection against catching the flu. The kind of mask that does keep out the flu is called a respirator and has a filtering rating of N95 from the National Institute for Occupational Safety and Health.

These disposable masks are an important protection for health care providers who deal every day with lots of patients with infectious diseases. But manufacturers haven’t been able to make them fast enough to keep up with demand, said J.P. Sankpill, president of U.S. Safety, a Lenexa, Kan.-based manufacturer and supplier of protective equipment.

Sankpill’s factory in Lenexa makes air purifying respirators with replaceable filters. They afford the same protection as disposable respirators but are designed for repeated use. U.S. Safety also sells regular N95 respirators from other manufacturers.

“As it stands right now, there are lots of hospitals running out or that have run out of N95 respirators,” Sankpill said.

The federal government had estimated in 2007 that billions more of these disposable masks would be needed during a pandemic, but it hasn’t done anything to help manufacturers build up their production capacity, Sankpill said.

“This has been a known issue for two years at least, and for now it’s too late (to increase the supply),” he said.

Going overboard?

For the average person, N95 respirators may be protective overkill. They’re more expensive than surgical masks and can be unpleasant to wear for any length of time.

“Some folks have been wearing them all day or whenever they go out, and they’re uncomfortable and they get hot,” Mueller said.

To be effective, an N95 respirator has to be fitted properly so it is sealed on the face. That’s not a job for amateurs.

When hospital workers are issued respirators, they go through a “fit test” that can take 20 minutes or longer.

After a worker dons the respirator, a hood is placed over his or her head. Chemicals with strong sweet or bitter tastes are squirted under the hood. If the worker can detect the chemicals, it means the respirator isn’t well sealed.

“The odds of the general public being fit-tested are slim to none,” Sankpill said.

Searching for flu-fighting supplies?

Here’s what to look for:

Sanitizing hand gel: The gel should be at least 62 percent alcohol to be effective killing germs.

Face masks: Surgical masks will protect others from your coughs and sneezes. Properly fitted N95-rated respirator masks will protect you from flu viruses.