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Germ-killing products have never been in higher demand than since Covid-19 turned into a global pandemic — but there’s little evidence that they’ve done anything to help slow the spread of the virus. In fact, the huge spike in hand sanitizer usage might actually be an accomplice to the spread of germs. That’s right, it had to be said, and someone just said it. Is it possible that this hygiene habit is doing more harm than good?

Let’s take a look at five major problems with traditional hand sanitizer.

1. Toxicity

Hand sanitizers can include a wide variety of chemicals, some of which are toxic and can cause harm to human health. Alcohol is one of these, but it’s typically considered one of the lesser offenders (more on that later). Worse is something called triclosan, which leads to hormonal imbalances in humans and other animals.

Triclosan is absorbed through the skin and may harm the body’s immune system and create antibiotic-resistant bacteria. The FDA has banned triclosan in most hand sanitizers, but that doesn’t mean you won’t come across it — the agency’s ability to control substances depends partly on how they are marketed.

Parabens and chemicals that make up the fragrances in “scented” hand sanitizer are other examples of ingredients to be wary of.

Related: How Ecommerce Is Being Forced to Evolve in a Post-Covid World

2. It kills good guys too

Skin is our body’s first line of defense as it kills off invaders by maintaining a slight acidity on its outer layer, called the “acid mantle.” Even regular handwashing in soap and water is enough to disrupt that mantle, but alcohol-based sanitizers take it to a whole new level. After using them, it takes about 12 hours for the skin to build up its protective layer of acid again. In the meantime, the skin is left more penetrable and absorbent for any and every would-be invader.

This phenomenon has been well documented. In this study, for instance, people who handled receipts after using hand sanitizer tested higher for bisphenol A (BPA) in their bodies than people who didn’t use any. Yes, the hand sanitizer does kill a large number of bacteria on your hands — but all the toxins and bacteria you touch after using the product get a free pass to get in your body.

Speaking of killing bacteria, alcohol-based sanitizer is pretty good at it, but it doesn’t differentiate between the good and bad kind. Healthy bacteria are part of the immune system, so destroying them just makes you more vulnerable.

Additionally, constant sanitizing that doesn’t kill all the germs can make them return even stronger by killing only the weak germs and leaving the strong. This can lead to the mutation of highly resistant strains. Ironically, hand sanitizers aren’t good at killing most viruses — and this is something we’ve seen before.

3. Severe dry skin

The alcohol found in traditional sanitizers dries out skin and banishes natural oils. Dry, cracked skin isn’t just a cosmetic concern though — those cracked areas are like open doors for bad bacteria and viruses.

Amid the rush to wash our hands and put on hand sanitizer like there’s no tomorrow, most people have been overlooking an equally important recommendation — those hands need to stay moisturized too. On top of being uncomfortable, broken or chapped skin makes hands harder to disinfect and also makes a person less likely to scrub them thoroughly.

Anything can get through cracks in the skin, but it’s probably not just Coronavirus you should worry about here. Instead, it’s MRSA, strep and other nasty infections that could be the ultimate consequence of overdoing it with sanitizer.

Related: Coronavirus: 21 Ways to Disinfect Your House During the Pandemic

4. It can be contaminated

As if the ethyl alcohol in alcohol-based hand sanitizers isn’t bad enough, a number of brands have actually been found to contain methanol, which is highly toxic to humans when absorbed through the skin. Nausea, vomiting, headache and even blindness can be the unfortunate consequences of just trying to be hygienic with methanol-based sanitizers. And companies aren’t forced to disclose this.

The main way to determine what type of alcohol is in a bottle of sanitizer is to test it in a laboratory — but there is also a very different smell to different alcohols, so pay attention to the smell and feel of the gel. If in doubt, definitely do not use it on children.

At this point, there are over 100 hand sanitizer brands that the FDA says not to use, and the agency also recommends avoiding other products made by the same manufacturers. These aren’t just fringe items ordered online either — many of them have been widely offered at well-known national retailers. And let’s face it, the FDA does not have the resources to check all of the hand sanitizers suddenly being sold for dangerous and harmful ingredients. So, buyer beware — make sure you trust the brand you’re using.

Related: How to Take Care of Your Gadgets as You Work from Home Amid Covid-19

5. It’s a symptom of a larger problem

It’s understandable that we’re all more interested in staying clean and healthy during an ongoing pandemic. The problem arises when misinformation — like a blanket recommendation to use hand sanitizer indiscriminately — actually ends up taking us backward. 

The human body is an amazing organism. The skin maintains an ecosystem specifically to keep the bad stuff out and the good stuff in. Once upon a time, we didn’t even realize that germs existed; now it seems like the pendulum has swung all the way in the opposite direction.

With a little more knowledge and education on the right topics, hopefully, we can find a balance between doing everything we’re told and being responsible enough to research our options and make the right decisions for our bodies.