First, not all hand-washing is equal. Experts estimate that only 5 percent of people correctly wash their hands. Some people, for example, don’t use soap or don’t lather long enough. But if hand-washing is done right, your drying method shouldn’t matter — thoroughly washed hands have no bacteria to spread. If you don’t completely wash your hands, however, bacteria may still be present when you’re ready to dry. And that’s when the difference between hand dryers and paper towels might matter.
Hand dryers can blow bacteria from your hands into the air, spreading it to nearby surfaces and back to your body. One study at the University of Westminster claims that using hand dryers actually increases the presence of germs by 225 percent.
Hand dryers blow warm air, which is conducive to bacterial growth.
Paper towels, on the other hand, rub bacteria and water from your hands without spreading germs, generally making them the more hygienic option in a public restroom.
For places like hospitals and clinics where hygiene is very important, paper towels may be the better choice. This helps prevent contamination from residual bacteria. But by far the most important part of hand washing is using good technique.