Why hydrogen peroxide foams on the wound: entertaining chemistry

Hydrogen peroxide( H2O2) is a substance that is freely available at the pharmacy. The peroxide that we buy is a 3% solution: that is, a 97% water bottle with water consists of water. Peroxide of hydrogen in this solution accounts for only 3%.

Most people use this substance as an antiseptic. Although it is not widely known that peroxide is not effective as an antiseptic. Nevertheless, it does not harm, falling on cuts and scratches, moreover, when it comes into contact with the wound, peroxide forms a spectacular "show."So why hydrogen peroxide foams on the wound? What is the scientific explanation for this spectacular phenomenon? Learn in the article.

Why does hydrogen peroxide foam on the wound?

The reason foaming occurs is that the blood cells and the blood itself contain an enzyme called catalase. Since a cut or scratch is always accompanied by the release of blood and damaged cells, a lot of catalase is always formed around the wound. This is understood, but still, why hydrogen peroxide foams on the wound? When catalase contacts it, it turns hydrogen peroxide( H2O2) into water( H2O) and oxygen( O2).

Catalysis performs the process of splitting peroxide into water and oxygen extremely effectively - up to 200,000 reactions per second. Bubbles that we see if hydrogen peroxide is foaming on the wound are oxygen bubbles formed as a result of catalase action.

Entertaining Chemistry

If you try to remember the school chemistry lessons, then in your head there will certainly be images: in the class on the potato slice the teacher pours a small amount of hydrogen peroxide - the same thing happens. The teacher asks: "Why is hydrogen peroxide foaming on the skin you have injured and on the potatoes?" Without waiting for an answer, the teacher himself answers: "Because in the damaged cells of the potato, like damaged cells of the epidermis, catalase is released."

Peroxide does not emit foam in a bottle or on a whole skin, because they do not contain catalase, which causes the reaction. Hydrogen peroxide is stable at room temperature.

Have you ever wondered why bubbles of hydrogen peroxide on a cut or wound appear, but it does not bubble on intact skin?

Why hydrogen peroxide foams and hisses: the scientific explanation of

So, we found out that hydrogen peroxide turns into vesicles when it comes into contact with an enzyme called catalase. Most cells in the body contain it, so when the tissue is damaged, the enzyme is released and becomes available for reaction with the peroxide.

Catalase allows the decomposition of H2O2 into water( H2O) and oxygen( O2).Like other enzymes, it is not used in the reaction, but is recycled to catalyze more reactions. Catalase supports up to 200,000 reactions per second.

Bubbles that we observe, pouring antiseptic on the cut, are bubbles of gaseous oxygen. Blood, cells and some bacteria( for example, staphylococci) contain catalase. While on the surface of the skin it is not contained. Thus, peroxide, in contact with intact skin, does not react, and the bubbles do not form.

In addition, since hydrogen peroxide has such a high level of activity, this substance has a certain shelf life after dissection. In other words, if bubbling is not observed when hydrogen peroxide is applied to a wound or a blood cut, it is likely that the peroxide is no longer active, and its shelf life has long expired.

Hydrogen peroxide as an antiseptic

The earliest use of hydrogen peroxide was as a bleach, because oxidation processes have a good effect on the change or destruction of pigmented molecules. However, since the 1920s, peroxide has been used as a powerful disinfectant. Therefore, the question: "What hydrogen peroxide foams on the wound?" - people have been asking for more than the first century.

Healing properties of peroxide

Chemical characteristics of peroxide provide the fact that it is capable of treating wounds in several ways. Firstly, since this is an aqueous solution, peroxide helps to wash off dirt and damaged cells and "loosen" the crust from dried blood. Bubbles in this case help to remove debris from damage.

Although it is worth noting that oxygen released by peroxide does not destroy all types of bacteria. In addition, the peroxide has strong bacteriostatic properties, which means that the use of hydrogen peroxide on the wound can prevent the growth and multiplication of bacteria. Peroxide acts as a sporicide, killing potentially infectious fungal spores.

However, it does not represent an ideal disinfectant, as it also destroys fibroblasts. It is a type of connective tissue that the body cells use to quickly heal wounds and repair damaged skin areas.

Therefore, peroxide should not be used as an antiseptic on an ongoing basis in the treatment of wounds, as it can slow the healing process. So, most doctors and dermatologists advise not to use it to disinfect open wounds, because this only aggravates the situation.

Verification: the peroxide is active in the

bottle. After all, hydrogen peroxide consists of water and oxygen, that is, using peroxide on the wound, you basically use ordinary water. Fortunately, there is a simple test to make sure that the vial with hydrogen peroxide contains the active substance: just throw a small amount of liquid into the sink. Metals( for example, near the drain) catalyze the conversion of peroxide to oxygen and water - that's why hydrogen peroxide foams on the wound and even on the sink!

If bubbles form, you can be sure: peroxide is effective. If you do not see them, it's time to go to the pharmacy for a new bottle of hydrogen peroxide. It is worth recalling that the shelf life of the drug helps to keep the medicine in the right conditions. Make sure it is in a dark container and in a cool place.