Can the Internet celebrity dry hair spray be used? Is it harmful to the human body? Frontline experts come to answer

Image source: Tuchong Creative

Recently, there are many popular dry hair sprays on the Internet. The main selling point is that you can make the greasy hair fluffy again by spraying the hair, achieving the effect of no need to wash. It is said that using this spray can also make the hair roots fluffy, increase the top of the head, and create the effect of airy hair.

So, do these dry hair sprays actually work?

Experts from the Institute of Biology of the Chinese Academy of Sciences responded that it is indeed effective. The specific principle is binding, adsorption, condensation and shedding.

First of all, binding refers to the surfactant binding to grease. Surfactants can react with alkaline substances such as caustic soda (NaOH), soda (Na2CO3), baking soda (NaHCO3), etc. to form stearates to achieve a cleaning effect.

Take the soap bean, a cleaning product used by the ancients, as an example. The stearic acid contained in the soap bean is a surfactant. One end of the stearic acid is a long fatty acid. It can combine with the oil molecule, which is also a fatty acid, and "like attracts like" and like dissolves like. They have similar structures and can dissolve in each other. The other end is one end of the inorganic salt molecule, which can be soluble in water. In this way, one end of the surfactant pulls the oil molecule and the other end pulls the water, so that the oil molecule dissolves in the water and achieves a cleaning effect.

(Figure: Stearic acid cleaning process. Inorganic salt on the left, fatty acid on the right)

Secondly, sedimentation. The specific process includes adsorption, condensation and sedimentation. The surfactant combines with the oil, which is only the first step. Because the binding substances are still on the hair, if you want to clean them thoroughly, you need to let them fall off, that is, sedimentation. The ingredients of dry hair spray include talcum powder or starch. These powders collide with the binding substances, adsorb, and then condense. As you comb your hair, they will fall off the hair.

The entire cleaning process, the corresponding method of using dry hair spray is:

Shake before use: to allow the spray ingredients to mix thoroughly;

Spray evenly on the hair, grab it with your hands, and massage for a while: increase the combination of surfactant and oil;

Let it stand for a while: let the two react fully and condense together;

Finally, use a comb to remove excess white powder on your hair: allow the adsorbent that has absorbed oil condensate and surfactant to settle down and leave the surface of the hair, thereby achieving the purpose of removing oil.

The question is, is this cleaning method harmful to the body?

Experts say it is basically harmless. The entire cleaning process is equivalent to dry shampooing. Compared with traditional shampooing, dry hair spray only uses adsorption, gel and sedimentation to replace water washing.

The ingredients in the spray mainly include surfactants, adsorbents, solvents, sprays and other ingredients. The surfactant is an ingredient contained in soap, laundry detergent and shampoo, which can achieve a cleaning effect. The adsorbent mainly uses starch or talcum powder, which can absorb stains and dry. Solvents generally use ethanol and water, which can dissolve the above ingredients and facilitate uniform distribution. Sprays, such as butane, isobutane, propane, etc., can help the spray to spray out normally from the nozzle. In addition, some manufacturers will add other materials as needed, such as fragrances to add aromatic smells, conditioners for hairdressing effects, etc.

It is worth noting that basically harmless does not mean completely harmless! For example, improper use of fragrances can cause discomfort to some people; some products contain distearyl dimethyl ammonium chloride, which is irritating to the eyes and skin. Therefore, when using it, avoid spraying it into the eyes. In addition, ingredients such as butane and ethanol also have the risk of explosion, so when using dry hair spray, stay away from open flames.

Some netizens said that after using the spray, the pores will be clogged. This statement is mainly aimed at the powder in the spray ingredients. Such as talcum powder, starch, etc., which may clog the hair follicles or sebaceous glands on the scalp. Experts said that in actual use, talcum powder and starch ingredients can be removed by combing the hair or wiping with a dry towel. Therefore, pore clogging is rare, unless it is used improperly, such as spraying too much and adhesion caused by sweat.

In summary, dry hair spray can indeed bring us a more convenient way to clean hair. But whether dry hair spray can be used for a long time depends on the individual. After all, the one that suits you is the best. In addition, when buying spray, you should also buy products with approval numbers on regular shopping platforms or large supermarkets. Don't be greedy for cheapness and buy products from informal channels.

Source: China Science and Technology Press