After using the chopsticks for a few months, the color at the top becomes darker, and even if you rinse it carefully, you can't seal it. 

Many people do not care about this, in fact, it is a symbol of the need to replace new chopsticks. 

Usually, the color of chopsticks becomes darker after 3 to 6 months of use. 

The long-term accumulation of bacteria is the primary factor in the color change of seizures. 

In addition, putting chopsticks in the cabinet for a long time can speed up the "metamorphosis" of chopsticks, and even multiply "aflatoxin", causing cancer. 

Household chopsticks have a service life of half a year. Once they change color, they should be replaced even if they are less than half a year. 

After cleaning, chopsticks should be put in a dry and ventilated place to dry, conditionally can be put in the disinfection cabinet, or often let chopsticks bask in the sun. 

In order to extend the service life of chopsticks, one is not to bite chopsticks when eating. 

If the head of chopsticks is bitten, the grooves on the appearance will be stained with a lot of residual food crumbs, greasy and other dirt. If they are not clean, they will multiply all kinds of bacteria and germs, such as Helicobacter pylori simply conveyed on chopsticks, resulting in gastroenteritis. 

Second, do not use eating chopsticks to fry food, because bamboo and wood chopsticks will become carbonized and blackened after frying, resulting in poor hardness, simple mildew, dregs, dirt and dirt, while lacquered chopsticks are rich in lead, chromium and other heavy metals. Frying can lead to heavy metal poisoning and the risk of cancer. 

Therefore, fried food with special bamboo chopsticks.