Is the TikTok video correct in advising against using hand dryers?

In recent days, a user experiment that made visible the amount bacteria that grows under the hand dryer hot air, as in public toilets. For this he used Petri disheswhich are those plastic plates with substances on which microbes are planted and allowed to multiply in the laboratory.

This is not the first time this topic has been discussed. In fact, there are many scientific studies comparing microbial growth with different hand drying methods. Typically, the use paper towels using hand dryers. Although other variables can be introduced, such as drying on the clothes themselves or in the air. In this TikTok video they compare dryers to something as simple as Shake hands.

The result leaves hand dryers in a very bad place, as are some scientific studies. But to what extent should we run from these devices? we can consider them dangerous? The answer is not as simple as yes or no, as it depends on many factors.

How hand dryers work

Generally speaking, hand dryers contain electrical resistance and fanformed by the impeller and the electric motor. When connected to a current, the temperature of the resistance rises, which begins to generate heat. But, in addition, the motor turns the impeller, which releases a jet of air heated by the effect of resistance.

There are hand dryers that inflate only one of the parts, so they can be divided into devices. jet or hot air. Whatever type they are, they all have a rather negative reputation due to their association with microbial reproduction. For this reason, many studies on this subject have been published in recent years.

Is TikTok video correct?

In evaluating both the results of the TikTok experiment and all these scientific studies, it is necessary to distinguish between environmental bacteria and those that were before in hand.

It is clear that most microbes use moisture for reproductionTherefore, it is important to dry your hands well after washing them. Whatever the method.

With this in mind, we can distinguish between different drying methods. A study published in 2019 compared drying on clothes, paper towel, two paper towels, hair dryer for 20 seconds, with hands still or chafed, and with a hot air dryer, until hands are completely dry.

In this case, the number of bacteria on the hands was measured before and after drying, and it was observed that the best way to eliminate them was with a hand dryer without rubbing them against each other. Another interesting fact emerging from this study is that there is no difference between using one or two paper towels, so better for the environmentIf you prefer to avoid hand dryers, use only one.

But what about the microorganisms that remain in the air? This is a different issue. In 2014, a study was conducted that measured the levels of microbial contamination of the ambient air after hand drying. using hot air dryers, jet dryers or paper towels. Lactobacilli were applied to the volunteers’ skin to mimic poorly washed hands, so some contamination could be expected. But it was much higher with hand dryers, especially jet dryers.

Perhaps in an environment where sick people are not expected to be abundant, this will not be a problem. For example, it could be a bar. However, the study concludes that in places such as hospitals yes, these drying methods should be avoided.

On the other hand, it should be noted that the most recent reviews of the scientific literature state that no hard evidence to avoid hand dryers. Yes, there is a great harmlessness of paper towels. However, there is no clear evidence against dryers.

Exactly because of this reason, outside the hospital, it shouldn’t be a problem to use these machines. While it is clear that paper towels are a safer option that has much more evidence.

Now, what about TikTok videos? The results are frightening, but apart from the anecdotal, cannot be compared with scientific research with well thought out conditions. In addition, the comparison with a handshake, not even talking about paper towels. Shaking hands usually means leaving them wet, which is a bad idea if we want to avoid germs. This is a viral TikTok, nothing more. What matters is interesting, but we shouldn’t get hung up on results.