Even the most expensive cosmetics can’t be bought like this-

Due to the poor quality of many cosmetic products, not only cannot beautify and rejuvenate the skin after use, but will bring disaster to the skin on the contrary. Some cosmetics are contaminated by bacteria and deteriorate, and they will also damage the skin after use. Therefore, before buying and using cosmetics, you must learn to test cosmetics, mainly for the following points. At present, there are so many types of cosmetic products on the market that it is dizzying. Due to the poor quality of many cosmetic products, not only cannot beautify and rejuvenate the skin after use, but will bring disaster to the skin on the contrary. Some cosmetics are contaminated by bacteria and deteriorate, and they will also damage the skin after use. Therefore, before buying and using cosmetics, you must learn to test cosmetics, mainly for the following points. (1) Observe whether its color has changed. Because bacteria produce pigments during the growth and development process, it can make cosmetics yellow and black. (2) Observe whether there is a smell or a strange smell. Due to the bacterial growth accompanied by the fermentation process, the organic matter in the cosmetics is decomposed, resulting in sour taste and smell, which no longer has the original aroma, but a disgusting sour and strange smell. (3) Observe whether it becomes thinner and water comes out. Because bacteria contain active enzymes that hydrolyze proteins and lipids, they can decompose proteins and lipids in cosmetics, destroy the original emulsified state of cosmetics, and precipitate the water originally contained in the emulsified structure. In addition, cosmetics are subjected to long-term overheating in a sterile state, and they will become thinner and water out after supercooling (that is, the oil layer and the water layer are separated). (4) Observe whether there are mold spots of various colors on the surface. This is due to mold pollution and mildew, which is easy to occur in spring and autumn. The temperature for mold growth is 24-28 degrees, and the relative humidity is greater than 70%. Anyone who has one of the above situations, even if it is a very high-end and very cheap cosmetic product, should refuse to buy it and prohibit its use to ensure safety. In addition, allergic reactions and chronic irritation reactions should be prevented during the use of cosmetics. Allergic reactions manifest as itching, erythema and papules, and even vesicles that cause secondary infections. People who have a history of allergic reactions can do a test first, apply a little of the cosmetic product on the ear, observe for a few days, and use it with confidence if there is no reaction. Chronic irritation from cosmetics can roughen the skin surface and thicken the keratinized layer. Therefore, it should be removed in time after use (such as sunscreen, etc.).