Baltimore ? When Sandy Summers picks up her children — ages 6 and 10 — at elementary school, they’re greeted with squirts of hand sanitizer.

“When they get in the car, I put a glob on their hands,” said the nurse, who lives in the Homeland area of Baltimore. “If they’re going to eat a snack in the car, I make them use some. … If I go to the grocery store, when I get in the car, the first thing I do is use the sanitizer. If I forget to use it before I touch the steering wheel, I put a whole bunch on my hands and just wipe it all over the steering wheel.

“With the flu season approaching, I find that we’re using it more.”

‘Everyone has a role to play’

The germ-killing gel, foam and spray is suddenly everywhere, with dispensers bolted to walls in supermarkets, hospitals and kindergarten classrooms, with giant bottles standing guard at church services, with tiny ones stowed in purses, briefcases and backpacks. Fears of the pandemic H1N1 flu virus have led Maryland to install dispensers in the public areas of all 56 state office buildings.

Hand sanitizer has grown into a more than $112-million-a-year industry in the United States, and sales have been rising, in large part because of swine flu. With the mantra “wash your hands” virtually being shouted from the rooftops — President Barack Obama has encouraged it; “Sesame Street’s” Elmo is sharing the message in public service announcements — many people are using alcohol-based sanitizer as a quick and convenient alternative to good old soap and water.

And while efforts are being made to more frequently disinfect surfaces where the flu virus may live — subway cars and buses in Washington are undergoing weekly cleanings — governments and businesses are putting out sanitizer in hopes that people will protect themselves and others by using the stuff. Liberally.

“Everyone has a role to play in stopping the spread of flu,” said David Paulson, spokesman for the state’s Department of Health and Mental Hygiene. “Everyone has to take personal responsibility. That means keeping clean, covering your cough, getting the vaccine.”

Soap vs. sanitizer

The conventional wisdom among public health officials is that hand sanitizer works well, but soaping up at the sink is best because it is the only way to wash off dirt. But others say hand sanitizer may actually be better, especially since so few people wash their hands properly and because the gels are always at the ready when you have sneezed or pushed an elevator button or turned a doorknob.

“It’s actually better than soap,” said Dr. Philip M. Tierno Jr., director of clinical microbiology and immunology at New York University Langone Medical Center. “Soap and water does not kill germs. Soap and water washes them off your skin.”

“The best thing you can do for yourself is wash appropriately with soap and water, 15 to 20 seconds,” he said. “(But) most people don’t wash appropriately, because they don’t do it long enough, suds up appropriately, don’t get in between the digits.”

Studies have shown for years that people don’t wash their hands as often or as well as they should.

Alcohol-based hand sanitizers work only if their alcohol concentration is greater than 60 percent (some products have 40 percent), experts say. Less is known about products marketed as alcohol-free.

Few see much downside to the ubiquity of sanitizers.

“The hand sanitizer tends to be more convenient. It tends to be less of an issue of drying (out) your hands,” said Dr. Richard Boehler, chief medical officer at St. Joseph Medical Center in Towson. “If you’re washing your hands 20 to 30 times a day … hand sanitizers seem to do a better job of keeping the skin intact.”

Spike in sales

Sales of hand sanitizer have risen along with fears of the swine flu.

For the 12 weeks ended Aug. 9, sales in the category were up 19 percent from a year earlier, according to Information Resources Inc., a Chicago-based market research firm. The data come from supermarkets, drugstores and mass-market retailers, excluding Wal-Mart.

When it is made with alcohol, hand sanitizer — used properly — kills most every germ it comes in contact with, unlike some antibacterial soap products that have led to worries about antibiotic resistance (a claim NYU’s Tierno dismisses). Sanitizer kills down to the DNA of bacteria and viruses, Tierno said, meaning there is little chance of creating resistant organisms. But he cautions that, just as with hand washing, hand sanitizers need to be used properly. Be sure to use a quarter-sized dollop and rub it on the top and bottom of the hand, between the fingers and into the nail bed, he said.

Still, Dr. Allison E. Aiello, a professor at University of Michigan School of Public Health who has studied hand sanitizer, said that although there is obviously a benefit to good hand hygiene, no studies have been done to see whether sanitizers or soap and water are more effective at reducing the spread of influenza. But, she said, sanitizer “does not seem to be inferior.”