Is Polypropylene Safe?

The NIH Office of Research Facilities lists polypropylene (PP) as plastic number 5, with common items including aerosol caps, drinking straws, medicine bottles, ketchup bottles, and containers for yogurt, margarine, take-out meals and deli foods. FDA regulations at 21 CFR 177.1520 say olefin polymers, which include polypropylene made by the catalytic polymerization of propylene, may be safely used as articles or components of articles intended for use in contact with food, subject to the provisions of that section. The FDA says the law requires all materials used in products that contact food, including plastic packaging and cookware, to be authorized by the FDA before being marketed for that use, and that it reviews migration and toxicology data as part of that process.

On microplastics, the FDA says there is not sufficient scientific evidence to show that microplastics and nanoplastics from plastic food packaging migrate into foods and beverages. On microwaving, it says some plastic containers should not be used in a microwave oven because they can be melted by the heat of the food inside, and that the instructions that come with each microwave oven indicate the kinds of containers to use.

Recent studies focus on heat. A 2025 laboratory study in Scientific Reports found no endocrine disrupting chemicals in distilled water held in polypropylene cups and containers at 4 to 10 °C, but detected DEHP, DBP, BBP, BPA and nonylphenol at 40 to 100 °C, with DEHP released the most at 100 °C. A 2026 study in Toxicology Reports says polypropylene, commonly used for food storage and microwave heating, has the potential to release microplastics when exposed to heat or prolonged use.