Scrubbing is key to keep hands bacteria free

To get hands really clean, many people have suggested washing them for as long as it takes to sing “Happy Birthday” twice.

To find out if it really matters how long you wash your hands, WRAL News talked with North Carolina State University assistant professor and food safety specialist Ben Chapman.

To contaminate hands, Chapman uses a product that mimics bacterial contamination, then views the results under a black UV light. Testers then wash their hands to see how well they are washing the bacteria off. 

Chapman said many people miss the top of the hands, fingertips and nails. Drying your hands with a paper towel also makes a difference. 

"You can reduce bacteria 99 percent by just rubbing and the friction used in that drying stuff," he said. 

So, it doesn't matter how long hands are washed. The quality of the washing and drying on a clean, dry paper towel are more important.