What is the correct procedure for hand washing?

The correct procedure for hand washing emphasizes the importance of using warm water and soap for an adequate duration to ensure that hands are thoroughly cleaned. Warm water helps to effectively dissolve oils and dirt, making it easier for soap to create a lather that can lift contaminants from the skin.

Washing for 20 seconds is crucial, as this duration has been shown to significantly reduce the presence of germs and bacteria on hands. It allows enough time to cover all areas of the hands, including between the fingers and under the nails, ensuring a complete clean.

Using an air dryer, as opposed to wiping with a towel or napkin, minimizes the risk of re-contaminating the hands post-wash and is considered a more hygienic option. This technique not only adheres to best practices for maintaining cleanliness but also aligns with health recommendations aimed at preventing the spread of illness.

The other choices do not meet these essential criteria; either they suggest shorter washing times, incorrect water temperatures, or inappropriate drying methods that could hinder effective hand sanitation.