Which of the following statements is true regarding hand sanitizers?

Hand sanitizers are designed to kill a significant amount of germs and are particularly useful in situations where soap and water are not available. They contain alcohol or other antimicrobial agents that effectively reduce the number of germs on the skin when used properly. This makes them a practical alternative for maintaining hand hygiene, especially in settings where immediate access to soap and water is limited, such as in public places or during travel.

The other options present concepts that do not accurately reflect the proper guidelines around the use of hand sanitizers. For instance, hand sanitizers are less effective on visibly dirty hands because soil, grease, and organic material can hinder their ability to kill germs effectively. Furthermore, while hand sanitizers are useful, they should not be viewed as a substitute for soap and water when the latter is available, as thorough handwashing is generally more effective in removing all types of germs and debris from the skin. Additionally, the effectiveness of hand sanitizers is not universally lower against all bacteria; many hand sanitizers are specifically formulated to be effective against a wide range of bacteria and viruses.