We often use saltwater to wash dishes or wounds, believing that saltwater can kill bacteria and viruses and achieve a disinfecting effect. But can saltwater actually disinfect and sterilize?
Can Salt Disinfect?
When the concentration of saltwater reaches a certain level, it does have a disinfecting effect. This is because high-concentration saltwater causes bacteria to undergo osmosis, leading to dehydration and death. Therefore, saltwater can disinfect to some extent.
High-concentration saltwater can indeed inhibit bacteria, but it cannot replace disinfectants to kill viruses because it is unable to do so. Disinfectants are preparations used to kill pathogenic microorganisms on carriers and render them harmless. Strictly speaking, saltwater cannot act as a disinfectant.
The Components of Salt
Salt is mainly composed of sodium chloride (chemical formula NaCl), which accounts for 99% of table salt. In some regions, potassium chloride is added to reduce the sodium chloride content and lower the incidence of hypertension. Iodine is also added to prevent iodine deficiency disorders, and salt with added iodine is called iodized salt.
Edible salt is usually made from rock salt or sea salt. On average, every 100 grams of refined salt contains 39,311 milligrams of sodium and 2 milligrams of magnesium. Rock salt is obtained from natural mineral deposits during geological changes and contains almost no minerals other than sodium and chloride. Sea salt, usually sourced from salt marshes, contains trace minerals such as calcium, magnesium, potassium, bromides, and various other trace elements.
What Concentration of Saltwater Has a Bactericidal Effect?
To disinfect wounds, physiological saline with a concentration higher than 0.9% must be used to be effective. However, the concentration should be controlled to avoid causing excessive pain when the wound is exposed to high-concentration saltwater.
If there are other disinfectants available, it is not recommended to use saltwater for disinfection because it is difficult to achieve the right balance between achieving the disinfecting effect and avoiding excessive pain caused by the high concentration of saltwater.
Handy Tips
The disinfecting effect of saltwater is not as good as we imagine. Although it can inhibit the growth rate of bacteria to some extent, the concentration requirement is also high. To completely kill bacteria, other methods such as high temperature or disinfectants should be used.
