Hydrogen peroxide (H2O2) is a substance that is freely available in a pharmacy. The peroxide that we buy is a 3% solution: that is, the bottle with the substance is 97% water. Hydrogen peroxide in this solution accounts for only 3%.
Most people use this substance as an antiseptic. Although few people know that peroxide is not effective enough as an antiseptic. Nevertheless, it does not harm, falling on cuts and scratches, moreover, in contact with the wound, the peroxide forms a spectacular "show". So why does hydrogen peroxide foam on the wound? What is the scientific explanation for this impressive phenomenon? Find out in the article.
Why does hydrogen peroxide foam on the wound?
The reason frothing occurs is because blood cells and the blood itself contain an enzyme called catalase. Since a cut or scratch is always accompanied by bleeding and damaged cells, there is always a lot of catalase around the wound. This was figured out, but still, why does hydrogen peroxide foam on the wound? When catalasecomes into contact with it, it converts hydrogen peroxide (H2O2) into water (H2O) and oxygen (O2).
Catalase performs the process of splitting peroxide into water and oxygen extremely efficiently - up to 200,000 reactions per second. The bubbles that we see when hydrogen peroxide foams on a wound are oxygen bubbles formed as a result of the action of catalase.
Entertaining chemistry
If you try to remember school chemistry lessons, then images will certainly appear in your head: in the classroom, a teacher pours a small amount of hydrogen peroxide on a potato slice - the same thing happens. The teacher asks, "Why does hydrogen peroxide foam on the skin you cut and on potatoes?" Without waiting for an answer, the teacher himself answers: “Because in the damaged cells of the potato, like the damaged cells of the epidermis, catalase is released.”
Peroxide doesn't foam in a bottle or on whole skin because they don't have catalase to cause the reaction. Hydrogen peroxide is stable at room temperature.
Have you ever wondered why hydrogen peroxide bubbles on a cut or wound but doesn't bubble on intact skin?
Why hydrogen peroxide foams and sizzles: the scientific explanation
So we found out that hydrogen peroxide turns into bubbles when it comes into contact with an enzyme called catalase. Most cellsthe body contains it, so when the tissue is damaged, the enzyme is released and becomes available to react with the peroxide.
Catalase allows you to decompose H2O2 into water (H2O) and oxygen (O2). Like other enzymes, it is not used in a reaction but is recycled to catalyze more reactions. Catalase supports up to 200,000 reactions per second.
The bubbles we see when pouring antiseptic over a cut are bubbles of oxygen gas. Blood, cells, and some bacteria (such as staphylococci) contain catalase. While on the surface of the skin it is not contained. Thus, peroxide, when in contact with intact skin, does not react and bubbles do not form.
Also, because hydrogen peroxide has such a high level of activity, it has a certain shelf life after opening. In other words, if no bubbling is observed when hydrogen peroxide is applied to a wound or bloody section, it is likely that the peroxide is no longer active and has long expired.
Hydrogen peroxide as an antiseptic
The earliest use of hydrogen peroxide was as a bleach, as oxidation processes are good at altering or breaking down pigmented molecules. However, since the 1920s, peroxide has been used as a powerful disinfectant. Therefore, the question: “Why does hydrogen peroxide foam on the wound?” - people are not the first to askcentury.
Healing properties of peroxide
The chemical characteristics of peroxide ensure that it can heal wounds in several ways. First, because it's an aqueous solution, peroxide helps wash away dirt and damaged cells and "loosen" the crust from dried blood. Bubbles in this case help to remove debris from damage.
Although it should be noted that the oxygen given off by peroxide does not kill all types of bacteria. In addition, peroxide has strong bacteriostatic properties, which means that the use of hydrogen peroxide on the wound prevents the growth and reproduction of bacteria. The peroxide acts as a sporicide, killing potentially infectious fungal spores.
However, it is not an ideal disinfectant because it also destroys fibroblasts. It is a type of connective tissue that the cells of the body use to quickly heal wounds and repair damaged skin.
Thus, peroxide should not be used as an antiseptic on a permanent basis in the treatment of wounds, as it can slow down the healing process. So, most doctors and dermatologists advise not to use it to disinfect open wounds, because this only aggravates the situation.
Checking if the peroxide in the vial is active
After all, hydrogen peroxide is made up of water and oxygen, so when you use peroxide on a wound, you basically use plain water. Fortunately, there is a simple test to make sure thatA bottle of hydrogen peroxide contains the active ingredient: simply throw a small amount of the liquid down the sink. Metals (for example, near drains) catalyze the conversion of peroxide into oxygen and water - this is why hydrogen peroxide foams on the wound and even on the sink!
If bubbles form, you can be sure that the peroxide is effective. If you don't see them, it's time to head to the pharmacy for a new bottle of hydrogen peroxide. It is worth recalling that storing the medicine in the right conditions helps to extend the shelf life. Make sure it is in a dark container and in a cool place.
