Is polypropylene recycling code 5 plastic safe for hot foods?

Short answer

Polypropylene, or recycling code 5, is common in food containers. It is a better fit for cool storage than hot food. For hot leftovers, soup, or takeout, use glass, ceramic, or stainless steel.

What the research says

A 2025 Journal of Agricultural and Food Chemistry study tested polypropylene food containers with hot and room-temperature water. The 90 C water released higher levels of polypropylene nano- and microplastic particles than room-temperature water. FDA says current evidence does not show that microplastics found in food pose a proven human health risk, but FDA also says major research gaps remain.

What to do at home

Let food cool before it touches polypropylene. Do not microwave plastic unless you are following the exact label instructions. For daily hot food storage, choose glass jars, ceramic bowls, or stainless steel containers.