Generally speaking, potassium permanganate will still have some effect after being exposed to moisture, but the effect is not as good as before. In clinical practice, potassium permanganate is a strong oxidizing disinfectant. If it is stored for a long time, the disinfecting effect of potassium permanganate will disappear after a certain period of time, and the disinfecting effect will not be achieved. When potassium permanganate is exposed to moisture, it may lead to dilution of potassium permanganate, and its disinfecting effect will be weakened, but the effect is not significant. Repeated use of high concentration of potassium permanganate may lead to corrosive burns. Potassium permanganate is contraindicated for oral use and for allergy sufferers. Precautions for the use of the drug include stopping the drug immediately if there is redness, swelling and burning after using the drug, this kind of drug needs to be used in combination with warm water, the high concentration of potassium permanganate should not be touched directly by hand when configuring the drug, and it is forbidden to use the potassium permanganate when its properties have changed, and so on. The use of potassium permanganate should be in accordance with the doctor’s instructions, and before use to ensure that it is within the period of use, do not use expired potassium permanganate for disinfection, because at this time it has been invalidated, can not achieve the disinfection effect.