Daniel Jee / Staff reporter
The reason people wash their hands is to remove countless invisible bacteria.
Unsanitary hands need to be in contact with soap, but thinking that many people use solid soap with germ-filled hands, a question appears in the head: is public bar soap safe to use?
Wouldn’t soap be contaminated if germs-filled hands contact with bar soap? And wouldn’t the soap make hands dirtier?
To answer this question, it is needed to understand the cleaning principle of soap first.
According to Defeatdd, soap is not a product that removes germs directly. Human skin is oily, so it doesn’t come off easily only with water when dust or germs get on it. For example, if someone washes their hands only with water when they have cooking oil on their hands, it will be slippery continuously.
The reason oil doesn’t be washed off well in water is that it is hydrophobic. Hydrophobicity is the opposite of hydrophilicity and refers to the lack of affinity with water. Most bacteria are hydrophobic, so it’s not washed well if people try to wash them just with water like oil.
So, people needed a cleaner which is friendly to both water and oil, and soap came out. In soap, there is a compound called surfactant. It consists of hydrophilic and hydrophobic parts, allowing soap molecules to melt into the water and fall off with oil when soap molecules adhere to the oil. In addition, since the surfactant of soap binds to the protein part of the virus and falls off, most viruses die when washed well with soap. In other words, the surfactant in soap tears and kills the virus.
People finally could easily remove foreign substances such as germs by making soap bubbles and rubbing their hands and save countless lives for a long time in history.
Also, soap commonly used to wash hands has a high pH (potential of hydrogen), making it difficult for bacteria to survive. pH is a unit indicating the degree of acidity or alkalinity of water, and high pH means alkaline (basic).
Instead, bacteria can live in soap bubbles. People foam with soap to wash their hands and put them on the soap stand. In that state, there are numerous bacteria in the foam and the bacteria can move from foam to pedestal.
In this regard, there are thesis materials published in 1965 and 1988. According to the papers, there were countless bacteria on the actual soap stand, and it was confirmed that bubbles in the hand using contaminated soap increased the number of bacteria. However, when someone washes their hands with water, germs will be washed away together, so there is no problem functioning as a soap. Meaning bar soaps in public toilets that everyone uses are safe.
Still, it is recommended to use liquid soap for people with bad or unstable immune systems in some cases. Liquid soap is isolated from the outside, so there is no need to worry. However, liquid soap tends to contain a relatively larger amount of flavoring, and it can be irritating to the skin because it foams a lot, so people should wash their hands properly after using liquid soap.
Whatever soap using, if people follow the right handwashing method, they can expect the original soap function. Wash hands thoroughly for 30 seconds. And don’t forget the fact that no matter how dirty the solid soap in the bathroom looks, it is surely cleaner than hands.
Sources:
Papers- bacteria in soap and its bubbles 1 2
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