Which is safer, ordinary pressure cooker, stainless steel or traditional aluminum?

The thermal conductivity of aluminum pot is much higher than that of stainless steel, and the thermal conductivity of aluminum is 10 times that of stainless steel. Aluminum pot is better than stainless steel pot if you don't use pots to store food for a long time. In addition, it is not good to store food in stainless steel pot for a long time, and it will also cause chromium in stainless steel to dissolve out, which is harmful to people's health.