Final answer:
The CDC recommends washing your hands for at least 20 seconds as part of the proper hand-washing technique. Humming the "Happy Birthday" song twice can serve as a timer.
Step-by-step explanation:
The proper hand-washing technique according to the Centers for Disease Control and Prevention (CDC) involves washing your hands for at least 20 seconds. To ensure you're washing long enough, you can hum the "Happy Birthday" song from beginning to end twice. This practice helps in effectively removing pathogens and preventing the spread of germs.
The key steps recommended by the CDC include wetting hands with clean running water, applying soap, lathering the backs of your hands, between your fingers, and under your nails, scrubbing for at least 20 seconds, rinsing well under running water, and finally drying your hands with a clean towel or air drying them.