Is Zhangqiu iron pot baking blue poisonous?

Roasting octopus in iron pan is not toxic, because what you said is normal, because it is a natural phenomenon after iron encounters high temperature, a chemical change after iron encounters thermal oxidation, and it is a normal phenomenon. Now, the idea that food is poisonous to each other has been denied. All the statements that you have heard before that certain food and certain food are toxic together are not true. They are all normal phenomena caused by chemical changes of iron after thermal oxidation, or iron will appear red and dark red when heated to 600 degrees. 800 degrees is orange red; Above 900 degrees, orange to bright yellow will appear; The melting point of iron is about 1535 and the boiling point is 2750℃. The reason why iron burns blue may also be related to impurities contained in iron.