7 questions and answers about hand hygiene

Does constant hand washing and disinfecting weaken our immune system? Does disinfectant dry out the skin? Are gloves an effective protection against diseases in everyday life? And can I actually use a home remedy to disinfect my hands? Questions like these are still on many people's minds even after almost three years of the pandemic. To mark Global Hand Washing Day on October 15, we want to shed some light on the most common myths about hand hygiene.

Hand hygiene is particularly important in autumn

For many, autumn is one of the most beautiful seasons. The leaves change colour, life becomes quieter, and you can really make yourself comfortable inside your own four walls. However, as in the last two years, the anticipation of autumn is clouded: while the temperatures outside are dropping, the number of Covid cases is likely to rise in the coming weeks, as many health experts confirm [1].

In addition to the impending Covid wave, the flu season is also on the horizon, starting in October and November. Proper hand hygiene is therefore still very topical. To raise awareness for this, the WHO has regularly organized the Global Hand Washing Day since 2008. Every year on 15 October, this day aims to mobilize people around the world to wash their hands regularly and thoroughly. The objective is to improve hygiene awareness and thus prevent the spread of infectious diseases.

But although Global Hand Washing Day has educated people for almost 15 years, the debate about "proper" hand hygiene is still dominated by ignorance and prejudice. We take a closer look at some of these issues and answer frequently asked questions:

1. Does disinfectant dry out the hands?

A woman disinfects her hands. — Disinfecting your hands is gentler on the skin than frequent washing.

It is often rumoured that frequent use of hand disinfectants stresses and dries out the skin. Many people think that simple hand washing with soap and water is gentler and therefore preferable. It is true that in most everyday situations, ordinary hand washing is completely sufficient to ensure effective protection against common viruses and bacteria.

However, disinfectant is actually gentler on the skin than soap. This is because soap dissolves the skin's own fats, which function like a natural protective layer. Frequent washing with soap can even dry out and chap the hands. The water temperature also plays a role, because very warm water dissolves the skin lipids even better, which can further accelerate the drying process. This provides the perfect opportunity for bacteria and viruses to enter and can result in irritation, itching, or inflammation [2].

Although hand disinfection also dissolves the skin's own lipids, unlike soap, alcohol-based products such as Sterillium® contain lipid-replenishing substances that can help the skin maintain its natural protective film. In some cases, disinfectants can even replace missing skin lipids [3].

2. Do disinfectants negatively affect the immune system?

Whether as dispensers in the entrance area of stores, on the tables of restaurants, or as small companions in backpacks, disinfectants have undoubtedly become an iconic symbol of pandemic control in the last two years. To protect themselves and their fellow human beings from the virus, more and more people have begun regularly disinfecting their hands in everyday life [4].

However, this has also quickly attracted critical voices. Some fear that those who frequently use disinfectants to kill viruses, bacteria and germs would weaken their immune systems. The argument goes that the less the body must fend off microscopic enemies, the more it loses its "training" and the less resistant the immune system becomes. In other words, disinfectant use causes us to "go soft." Is there any truth in this?

The fact is that disinfectants generally do kill microorganisms that perform useful functions. For example, certain bacteria on the skin, in the nose, or in the intestines do protect the body from pathogens. It is therefore not desirable to make one's own body or household germ-free. But don't worry: It is not possible to achieve such a state of complete sterility through disinfection anyway. After all, the hands are only a very small area of the whole body. And besides, the body's own skin bacteria grow back from deeper skin layers after only a short time.

Hand disinfection is therefore not harmful to the immune system. On the contrary. After all, disinfection kills possible pathogens on the hands that could lead to infection. This makes hand disinfection very effective. However, it should not be forgotten, that diseases are also part of life. We will not get around having a cold from time to time. Everyone must therefore weigh up for themselves how intensively they want to protect themselves. Although the general state of health also plays a role here, the immune system is not weakened by the use of hand disinfectants.

A woman is blowing her nose. — There is no scientific proof that disinfectant use weakens the immune system.

3. Do gloves replace hand disinfection?

A man is putting on rubber gloves. — Gloves do not offer the protection that some people assume.

Be careful with gloves. The perceived safety is greater than the actual protection. The reason: diseases can also be transmitted with gloved hands, namely if the pathogens from the hands get into the mouth or nose and thus enter the body. Gloves therefore only protect against transmission if they are taken off immediately after possible contamination and the hands are then disinfected. There is no need to fear that the germs will penetrate the skin and make you ill [5].

In addition, especially when worn for over 30 minutes, the hands can become sweaty, which dissolves skin fats. This damages the natural protective layer, which in turn can promote skin irritations, allergies, and even eczema in the long term [6]. If you want to protect yourself from infection while being gentle on your hands, you should reach for soap or disinfectant.

4. Does hand washing replace hand disinfection?

Basically, hand washing and hand disinfection have different goals: Washing is about cleaning, for example removing dirt. Disinfecting, on the other hand, is specifically about killing pathogens. But washing also washes off pathogens, of course. You can learn more about this topic in our article "Hygiene Myths and Misinformation".

A woman is washing her hands at a sink. — In many common situations, hand washing is sufficient. However, it does not completely replace disinfection.

5. Are home remedies any good?

A man is cutting onions. — Certain household remedies such as onions are said to have an antibacterial effect. However, they cannot protect you from diseases such as Covid or the flu.

Onions, schnapps, or saliva: there are many well-known household remedies that are supposed to have an antibacterial effect. Most, however, are used to disinfect wounds. Sadly, neither onions nor vodka from the freezer will protect you from contracting infectious diseases such as the flu. Commercial disinfectants are the better choice in any case. These have been tested for effectiveness and optimised for tolerance.

But what about home-made alcohol-based disinfectants? In principle, this may be an option – for example, if the corresponding products are sold out, as was the case at the beginning of the pandemic. In such cases, pharmacies can also simply prepare disinfectants themselves from ethanol, hydrogen peroxide, glycerine, and distilled water, for example, following the WHO recipe [7]. However, this option is only permitted in exceptional case, as such homemade disinfectants do not meet the usual high-level standards in terms of efficacy and skin compatibility.

6. Is disinfectant still stable after the expiry date?

Disinfectants have an expiry date, not a best-before date. After this date, the products should therefore no longer be used, as the protection promised by the manufacturer can no longer be guaranteed. This is especially true for the health sector, but also in the private sector the product should be replaced after the expiry date [8].

And how long can you use a product after it has been opened? The shelf life depends on the respective product, but most products, such as Sterillium® can be used up to twelve months after opening without any problems. The prerequisite for this is, of course, correct storage.

One bottle of Sterillium®. — Once opened, disinfectants usually have a shelf life of up to twelve months. After that, they should be replaced.

7. How do I store disinfectants correctly?

A dispenser with disinfectant. — Disinfectants can be easily stored in dispensers.

To ensure that a disinfectant does not lose its effect, containers should be tightly closed after use. Another thing to consider is that hand disinfectants usually consist of about 70 to 80 percent alcohol, making them highly flammable. When storing them, care should be taken to keep them away from fire or sources of ignition. It is also important that the disinfectant is not exposed to excessive sunlight or heat [9].