Hand washing, along with wearing masks and maintaining social distance, has emerged as one of the most crucial preventive measures against Covid-19. Over the past year, as many of us scrubbed our hands with soap and water for at least 20 seconds, the importance of keeping them clean became a matter of both personal and public health.

On a day designated for reflection on this low-cost, life saving habit, we put together a list of things worth know about hand washing: