Roasting with fire, dissolving in water, rubbing salt, shaking foam … These cosmetic testing ＂crooked operations＂ won’t work.

　　Photo courtesy of vision china

　　Beauty cosmetics guide to avoiding pits

　　Reporter Jin Feng

　　If you want something beautiful, how can you do it without skin care and makeup? In the eyes of many beauty experts, today’s skin care and makeup process is not just as simple as "washing your face and applying a cream", but involves a series of steps such as cleansing, toner, cream and essence.

　　Before these operations, the quality of the product is the most important thing. In order to identify the quality of the product, there are various methods circulating on the Internet: "Facial cleanser is baked with fire, and if it is splashed with oil or baked more and more like yogurt, the safety factor is not high." "Shake toner, if there is less foam, it means less nutrients." "Put salt on lipstick and rub it. If there are black particles, it means that the content of lead and mercury exceeds the standard, never buy it. … Can these seemingly simple "earthworks" help us polish our eyes, and how can we choose the products that suit us?

　　Improper operation: baking facial cleanser with fire and spilling oil are not safe.

　　Positive solution: oil spills are caused by oily components or emulsifiers.

　　"Roasting with fire will spill oil, or the more it is roasted, the more it looks like yogurt, which does not explain the quality of facial cleanser." Chi Bo, a professor at the School of Food and Light Industry of Nanjing University of Technology and the State Key Laboratory of Material Chemical Engineering, told the Science and Technology Daily reporter that splashing oil when baking facial cleanser with fire can only prove that there are oily ingredients or emulsifiers in facial cleanser.

　　Chi Bo said that some facial cleansers with strong cleaning power and more soap-based surfactants will add some grease or emulsifier. Grease can reduce the degreasing power of soap-based surfactants and make facial cleansers softer to use. This facial cleanser will spill oil if baked with fire, but it does not mean that it is unsafe to use this facial cleanser.

　　As for why facial cleanser is baked more and more like yogurt, it is related to the formula of facial cleanser. Chi Bo said that some facial cleansers have high fineness, and the water evaporates after baking, and the molecular structure of the emulsifier has not been destroyed, so it will be very sticky, but this can only prove that its emulsification system is relatively stable and the facial cleanser will be stored for a relatively long time.

　　Since the method of identifying the quality of facial cleanser by fire roasting is not reliable, how to judge the efficacy of facial cleanser? "After using a good facial cleanser, the face is not tight." Chi Bo said, "In particular, it is not recommended for people with sensitive skin to use facial cleanser that makes the skin feel tight, because it will remove the oil that acts as a barrier on the skin surface."

　　Xu Yang, deputy chief physician of jiangsu province hospital Dermatology Department, also said that the main function of facial cleanser is cleaning. After cleansing, the skin is not tight, moist and dehydrated. If you want to moisturize the skin, you might as well use facial cleanser containing moisturizing ingredients such as glycerin and allantoin.

　　In addition, the pH value of facial cleanser is preferably weakly acidic. "The pH value of skin is about 4.1— 5.8, and the pH value on the market is 6-mdash; Facial cleanser between 7 can be used, and the pH value can be measured with test paper. Although the degreasing of alkaline or soap-based facial cleanser is better, if it is too alkaline, it may affect the pH value of the skin. " Xu Yang said that after the change of skin pH value, it will cause changes in skin flora. If the pH value increases, it will form an environment conducive to the growth of some skin bacteria such as propionibacterium acnes, thus increasing the probability of acne on the skin.

　　Chi Bo suggested that for people with oily skin, you can use soap-based facial cleanser containing dodecyl and laurate, but you should also beware of excessive cleaning and damage to skin oil. Excessive cleaning will make the skin dry and tight, and it will also open the pores completely, which will increase the chance of contact with germs and lead to skin allergies. People with neutral and sensitive skin are more suitable for facial cleanser containing amino acids and olive oil lipids.

　　Inclined operation: shake the toner, and there are many nutrients in the foam.

　　Positive solution: the content of surfactant determines the amount of foam

　　After washing your face, especially in hot summer, pat a little toner on your face, and a refreshing feeling will come to your face. So how to identify the advantages and disadvantages of toner? Some netizens suggested shaking the toner. If there is less foam, it means less nutrients. Is that true?

　　"The content of nutrients has nothing to do with the amount of foam." For this method circulating on the Internet, Chi Bo said that many ingredients in the toner will not produce foam, such as vitamin C, plant extract, salicylic acid and so on.

　　Xu Yang said that the ingredients in toner are both water-soluble and fat-soluble, such as hyaluronic acid and fruit acid, which are water-soluble ingredients, and glycerol and salicylic acid, which are fat-soluble. Surfactants need to be added to dissolve fat-soluble ingredients in water. Surfactants can cause foam when shaking, but surfactants do not affect the nutrition of toner.

　　Chi Bo further introduced: "In the production of toner, sometimes in order to dissolve essence and essential oil in water, it is necessary to add surfactant, which can increase the surface tension of the liquid, make all the substances evenly blend and form an oil-in-water system, so that various substances are not easy to delaminate and the storage time is longer."

　　How much foam you shake out can’t judge the substance content, so how to choose the toner that suits you?

　　Xu Yang said that the function of toner is mainly to moisturize and soften the stratum corneum. However, the use of toner should vary from person to person. People with oily skin can use some toner that softens the cuticle or contains alcohol. For people with sensitive skin, it is not recommended to use toner containing alcohol, fruit acid and salicylic acid easily. "Fruit acid and high concentration salicylic acid have exfoliating effect, etc. It is not recommended for people with thin cuticle." She suggested that for people with sensitive skin, if you can’t identify which toner is useful to you, you can use lotion or moisturizer directly without caution.

　　Inclined operation: the emulsion enters the water, but floats on the water surface and contains oilstone ester.

　　Positive solution: Sinking and floating surfaces are mainly determined by density.

　　An emulsion that looks as pure as milk is moisturizing and moisturizing. If a few drops are squeezed and dissolved in water, some emulsions float on the water surface and some emulsions sink into the water. Some emulsion identification methods circulating recently believe that the emulsion floats on the water surface, indicating that it contains oleoresin, which will harm the skin. Is this statement reliable?

　　Regardless of ups and downs, it can’t prove whether the emulsion will harm the skin. Xu Yang said that emulsion is generally composed of oil, emulsifier, preservative, perfume, excipient for adjusting pH value, etc. The density of the emulsion is determined by different preparation formulas and processes, and whether the emulsion floats on the water is determined by the density of the emulsion. If the density is greater than water, the emulsion will sink, otherwise it will float on the water. However, it can’t be said in general that the emulsion floating on the water will hurt the skin, which depends on the specific components and proportions.

　　Chi Bo believes that emulsions containing more oils are easier to float on the water surface. Most of these oils are light oils, such as mineral oils. The amount of oils will affect the skin feel and moisturizing strength of emulsions. Healthy skin is water-oil balance, and the best way to keep skin healthy is to protect the barrier function of skin. Too light and too thick emulsion is not suitable.

　　If you want to choose a suitable emulsion, you can also pay more attention to the ingredient list. Xu Yang believes that the most important function of lotions and creams is moisturizing. If you need anti-aging, you can choose an emulsion with substances such as alcohol A, vitamin C, vitamin E and peptides. Sensitive skin needs some emulsions that have anti-allergic effect and can repair the water-oil barrier, such as those with ceramide, purslane extract and licorice extract, which have certain anti-inflammatory effects. The emulsion containing vitamin C, arbutin, tranexamic acid and other substances is suitable for people who need whitening. Salicylic acid, fruit acid, almond acid and other substances can help fine pores and fight acne.

　　Oblique operation: rubbing salt on lipstick turns black, indicating that it contains lead and mercury.

　　Positive solution: The content of related substances can only be detected after nitration with strong acid.

　　Choosing a powerful lipstick will not only make your lips full and shiny, but also make your whole face feel makeup. Some netizens said, put salt on lipstick and rub it. If there are black particles, it means that the lead and mercury content exceeds the standard, so don’t buy it.

　　In this regard, Qu Mei, a senior engineer of the National Cosmetics Quality Supervision and Inspection Center, responded: "Not reliable." One of Qu Mei’s daily work is to check the quality of all kinds of cosmetics.

　　She said that whether the quality of a lipstick meets the standard needs to be reflected by its lead, arsenic, mercury, cadmium and total number of colonies, mold and yeast, Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli and other conventional indicators. To complete this detection process, it needs to go through a set of chemical experiments.

　　"When testing, we weigh the lipstick, add strong acid, and then heat it with an electric furnace. The strong acid will fully decompose the chemical composition of lipstick. Then put them in a high-temperature boiling furnace and burn them for several hours to remove all the organic substances in the lipstick, leaving inorganic substances. After dissolving inorganic substances, the contents of lead, arsenic, mercury and cadmium in cosmetics can be detected by atomic absorption or atomic fluorescence. Therefore, it is impossible to decompose lead and mercury just by adding salt at room temperature. " Qu Mei told the Science and Technology Daily reporter that lead, arsenic, mercury and cadmium are all prohibited ingredients in the production of cosmetics. The prohibited mercury can make the skin appear whitening in the short term, but lipstick has no short-term whitening demand, so there is no need to add it. The test results of cosmetics center for many years show that no samples of lipstick containing excessive mercury are found, so consumers don’t have to worry.

　　What are the black particles produced by the friction between salt and lipstick in the online video? Chi Bo said: "Black particles may be caused by sodium chloride destroying the paste system of lipstick, which changes the internal components. However, some merchants will not write all the ingredients in the ingredient list, and the composition of black particles is not easy to judge. "