There are so many misconceptions about such a simple task as doing laundry

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Washing clothes is something that every family does: soiling the clothes, washing them, and drying them. Thanks to the strong stain-removing powers of soap, detergent, and laundry pods, the clothes quickly become as clean as new. However, although clothes are washed frequently, many people still hold some misconceptions about this simple task of washing clothes that need to be corrected. Myth 1: Laundry soap can kill bacteria. It is said online that laundry soap is alkaline in nature, and this property can disrupt the osmotic pressure within bacteria, thereby helping to kill them. However, Liu Hongtao, an associate professor at Beijing University of Chemical Technology, told a reporter from Science and Technology Daily that the main component of laundry soap is surfactants, which can only remove stains from clothes and do not have any antibacterial effects; it is laundry soaps containing antibacterial ingredients that possess such effects. “Laundry soap generally has difficulty killing bacteria. ” Tang Yang, an associate professor at Beijing University of Chemical Technology, explained that laundry soap is weakly alkaline, with a pH value between 8 and 9, which is similar to the alkalinity of household baking soda. Bacteria have a thick cell membrane that gives them tolerance to weak bases, and they can only struggle to survive at pH levels above 14. “Bacteria exert their effect by binding to human proteins through their own proteins. ”Tang Yang said that if disinfectants are added to laundry soap, using it to wash clothes generates highly oxidizing substances that oxidize the proteins on bacterial cell membranes, causing them to lose their ability to bind with human proteins, thereby achieving the purpose of sterilization. He also suggested that when washing clothes with antibacterial soap, it is best to rinse them several times with water. Myth 2: Wearing new clothes without washing them can cause cancer. Some people say that wearing newly purchased clothes without washing them first can lead to cancer due to the formaldehyde remaining on them, which sounds like a pretty terrifying idea. Is this true then? New clothes contain a small amount of formaldehyde during the production and processing stages; it is used as an additive to provide wrinkle resistance, softness, shape retention, and improved appearance. Guo Zhongbao, deputy director of the First Inspection and Certification Institute of China Building Materials Inspection and Certification Group, said: “New clothes that meet the mandatory ** standards for textiles have a formaldehyde content within safe limits, even if they are not washed before being worn.” And after washing and wearing it again, the vast majority of formaldehyde will disappear. ”He told a reporter from Technology Daily that according to GB 18401-2010, the **Basic Safety Technical Specifications for Textile Products**, the formaldehyde content in clothing intended for infants and young children should not exceed 20 milligrams per kilogram. For clothing that comes into direct contact with the skin, the formaldehyde content should not exceed 75 milligrams per kilogram, while for clothing that does not come into direct contact with the skin, the limit is 300 milligrams per kilogram. “Not all of this formaldehyde is necessarily absorbed by the human body. ”Guo Zhongbao explained that formaldehyde in most clothes evaporates easily, and very little of it can be absorbed. Formaldehyde is soluble in water and can be washed away with detergent. The normal metabolic processes in the human body also produce small amounts of formaldehyde, and humans are not completely intolerant to it. “The toxicity of any substance is inseparable from the concept of quantity; it is only with long-term exposure to high concentrations of formaldehyde that harm occurs. ”However, wearing new clothes without washing them can cause itching, which may be related to formaldehyde irritating the skin. Therefore, Guo Zhongbao suggests that new clothes should be washed before wearing them. Myth 3: Soap and detergent cannot be used together. Many people say that soap is alkaline while detergent is acidic, and the two cannot be used together because acid and alkali will neutralize each other, preventing the clothes from being cleaned properly. However, experts hold the exact opposite view. “They can be used together; combining them may yield better results. ”Liu Hongtao said that the main component of both soap and laundry detergent is surfactants. When added to clothes during washing, these surfactants reach a critical micelle concentration, after which micelles are formed in water that \"eat away\" the oil stains and dirt on the clothes. Rinsing with clean water then makes the clothes clean, and the cleaning power is enhanced due to the \"synergistic effect\". Moreover, soap reduces the foaming capacity of laundry detergent; with less foam, it is easier to rinse. Furthermore, the claim that soap is alkaline and laundry detergent is acidic is also unfounded. Liu Hongtao said that soap is weakly alkaline, and laundry detergent is also weakly alkaline. Some people experience a feeling of \"heat\" in their skin on the hands when using laundry detergent; this is due to other additives. (Tang Fang)