If you're like most kids, you get reminded to do one certain thing all the time. Before you eat? Wash your hands. After you go to the bathroom? Wash your hands. You might get tired of the reminders, but they're good advice!

Consistent, frequent hand washing helps to kill germs and slow the spread of bacteria and viruses that can cause colds and the flu. Unfortunately, it's not always possible to get to a sink with soap and water. Fortunately, at those times, it is often possible to squirt some hand sanitizer gel that you can rub into your hands to keep them clean.

But does hand sanitizer really work? That's the question that's been on the minds of many of our Wonder Friends. We decided to find out and share what we learned!

Antibacterial hand sanitizers are marketed as an alternative to hand washing with soap and water. Hand sanitizers come in several varieties, including gels, foams, and liquids. They are meant to be rubbed directly onto the skin without adding water or needing to rinse.

Most hand sanitizers feature an alcohol-based active ingredient, such as isopropanol or ethanol. They may also contain a variety of inactive ingredients, including thickening agents, glycerin, essential oils, and fragrances.

You've probably noticed that many hand sanitizers boast that they kill 99.9% of germs. But do they? Scientists note that companies can make those claims, because their products do kill nearly all germs when tested on inanimate surfaces. They warn, though, that you might not get the same results when you use hand sanitizer on your hands.

Hand sanitizers work by removing the outer layer of oil on your skin. If you don't use enough hand sanitizer — or you don't rub it in thoroughly — less than 99.9% of the germs on your hands will be killed.

There are a couple of other situations in which hand sanitizers might not be as effective as you hope. If your hands are particularly dirty or grimy, hand sanitizer will likely not be very effective. Moreover, if you use a hand sanitizer that contains less than 60% alcohol, it will likely not kill most of the germs on your hands.

Researchers also note that the kinds of germs that hand sanitizers kill aren't necessarily the kinds that usually make you sick. While hand sanitizer may make your hands cleaner, it won't necessarily keep you from getting sick. Some studies, though, have shown that regular hand sanitizer use can reduce the number of days students stay home sick from school.

So do hand sanitizers really work? The conclusion most researchers have come to is that, yes, they do work, but they may not work as well as you expect them to. Plus, they may or may not reduce the likelihood of getting sick.

Most experts advise that you should not use hand sanitizer instead of soap and water. Whenever possible, wash your hands the old-fashioned way with soap and water. If you're in a situation where you can't get to a sink, though, hand sanitizer makes an acceptable alternative.

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