What is the main ingredient in most hand sanitizers?

The main ingredient in most hand sanitizers is alcohol, specifically ethanol or isopropyl alcohol. Alcohol acts as an effective antimicrobial agent, which helps to kill bacteria and viruses on the skin's surface. The high concentration of alcohol typically found in these products (usually around 60% to 95% alcohol) is crucial for their effectiveness; it denatures proteins and disrupts cellular membranes of microorganisms, leading to their destruction.

While other ingredients such as water, glycerin, and hydrogen peroxide may be present in hand sanitizers, they primarily serve as adjuncts. Water can be included to dilute the alcohol, glycerin can act as a moisturizer to prevent skin dryness caused by the high alcohol content, and hydrogen peroxide may be used for additional antibacterial properties. However, none of these contribute to the primary function of hand sanitizers in combating germs, which is achieved through the alcohol content. Therefore, alcohol remains the key active ingredient that defines the efficacy of hand sanitizers.