VC is able to change the color of povidone iodine from brown to colorless and transparent due to a redox reaction. When VC and povidone iodine come together, a redox reaction occurs. Povidone iodine is an oxidizing agent, and VC is a reducing agent. VC changes the monomer iodine of povidone iodine into an ionic state through reduction, and iodine ions are colorless, which causes the povidone iodine solution to change from a brown color to a clear white liquid. After the redox reaction, the effectiveness of povidone iodine is greatly reduced, so in the work or daily life, try to avoid the two together, if the povidone iodine appears to have a color change, it is not recommended to continue to use, replaced with new povidone iodine for disinfection.