It’s harmful.

Frying oil is generally changed every 3-4 days, but there are records of repeated use for up to 10 days. The cooking oil temperature in the pot is 360 degrees Fahrenheit (about 182 degrees Celsius) and is mainly used for frying various foods.

In fact, it is not fried all the time. During the frying process, oil will be consumed, and then new oil is added, basically shortening is used. In this way, the fried food will be crisper and golden in color.

Edible oil is not suitable for secondary high temperatures. The oil left after frying will become rancid at a greatly accelerated rate, and rancid oil will produce a lot of harmful substances. After eating, you will suffer from diarrhea in mild cases and severe cases in severe cases. Can cause liver disease.