Can cooking oil make nanoplastics from food packaging more dangerous?
Yes, in the tested model. A 2026 study found hot cooking oil greatly increased microplastic and nanoplastic release from PP and PE-coated containers and made particles more toxic to gut cells.
What it is
Plastic and coated paper food containers can shed microplastics and nanoplastics. Oily foods are a special concern because fat can pull chemicals and small particles out of packaging.
This matters most for hot, oily food: fried takeout, sauces, cheese, soups with oil, and leftovers reheated in plastic.
What the study found
A 2026 study in Advanced Science tested polypropylene and polyethylene-coated containers with cooking oil during microwave heating.
The study found that cooking oil increased microplastic and nanoplastic release up to 125x compared with water within 3 minutes of microwave heating. It also found up to 309x higher co-release of plastic additives and heavy metals.
Oil-derived polypropylene nanoplastics were more toxic to gut cells than water-derived particles in the study. In mice, oral exposure to oil-derived nanoplastics for 2 weeks damaged the intestinal barrier and disrupted mucosal immune function.
This does not mean every container releases the same amount. It does show a clear pattern: hot oil and plastic food packaging are a bad combination.
What to do
Do not microwave oily food in plastic or coated takeout containers. Move oily leftovers into glass, stainless steel, or ceramic. Use parchment or a plate when plastic wrap would touch fat.
For takeout, transfer food out of the container once you get home, especially if it is hot and oily.
The research at a glance
| Study | Journal | Year |
|---|---|---|
| Oil-Coated Nanoplastics Induce Rapid Membrane Disruption and Severe Intestinal Injury | Adv Sci (Weinh) | 2026 |