The fourth annual Healthy Hand Washing Survey conducted by Bradley Corp., a manufacturer of bathroom and locker room furnishings, found 57 percent of respondents estimated they washed their hands for 5 to 15 seconds.
The Centers for Disease Control and Prevention recommends washing for at least 20 seconds and suggests singing "Happy Birthday" twice to allow enough time to remove and rinse off germs.
The survey also found 70 percent of U.S. adults said they always washed their hands after using a public restroom, 29 percent said they sometimes skipped washing hands and 1 percent said they never washed after using a public restroom.
"We were surprised to learn that Americans don't increase their hand washing during the cold and flu season," Jon Dommisse, director of global marketing & strategic development for Bradley Corporation, said in a statement. "It's so important to know that hand washing is the best way to help your body fight off cold and flu germs."
The survey queried 1,046 U.S. adults -- half men and half women -- Aug. 1-3 about their hand washing habits in public restrooms. No margin of error was provided.