The surface of chopsticks is oxidized. Generally speaking, the color fading of chopsticks is related to the material of chopsticks. The raw material is wood or bamboo, and chopsticks themselves contain wood, which will dissolve a part in water, so it is normal for the water to turn slightly yellowish and will not be harmful to the human body. However, in the production and processing of chopsticks, some trace chemical reagents will be added, which may lead to the discoloration of chopsticks.