What are rainbow streaks on pots and pans, are they poisonous?

So, what are these rainbow streaks and are they harmful to the human body or are those pots a poor quality product?

Rainbow color streaks on the bottom of the stainless steel pot are a very normal phenomenon and are named "heat staining". This phenomenon does not affect the quality of the food or the health of the user.

The cause of these marks is that the pots and pans are usually made of stainless steel. To prevent rust and corrosion, a small amount of chromium is added to this steel. Chromium will create a protective layer when exposed to air.

When stainless steel is heated at high temperature, the oxygen layer will thicken and form rainbow streaks to help protect stainless steel pots and pans and they are not harmful to human health.

Many people wonder that chromium is toxic, but in fact, chromium in the Cr6+ state (toxic compound) is difficult to oxidize.

How to clean stains on stainless steel pots and pans

There are two ways to remove rainbow stains on stainless steel pots and pans.

White Vinegar

1. Mix white vinegar with water in a ratio of 1:5.
2. Pour the mixed solution on the area where the stain appears and let it sit for 10-15 minutes. Or you can use a sponge soaked in vinegar to gently clean these rainbow stains.
3. Rinse and dry the pot with water.

Use lemon

Use half a lemon to rub directly on the stain and then rinse with water.