Can you microwave plastic containers?
You can, but it's the clearest route for plastic particles into your food. Reheat in glass or ceramic instead.
By PlasticFreeHome Research Team · Reviewed by Khalid · Updated 21 October 2026 · 1 min read
Technically yes, but it's the single swap we rank highest for food storage: heating food in plastic releases far more particles than anything else you do with a tub. Reheat in glass or ceramic, or put a plate over a bowl.
What happens when plastic is heated
Heat softens plastic and speeds up the release of particles and chemicals. A 2023 study microwaved common polypropylene and polyethylene containers and found very large numbers of micro- and nanoplastic particles released per square centimetre, far more than at room temperature or in the fridge.
What "microwave safe" means
"Microwave safe" means the container won't melt, warp or crack in the microwave. It doesn't mean nothing moves from the plastic into your food.
Easy ways to stop
- Tip food into a glass or ceramic bowl before reheating.
- Cover with a plate, not the plastic lid or cling film.
- Keep plastic tubs for cold storage only, and replace scratched or cloudy ones.
- Never reheat in takeaway containers.
See the full swap: reheating in plastic tubs → glass containers.
Sources
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Top swaps in food storage
Reheating in plastic tubs → glass containers
Heating food in plastic is the single clearest route for plastic particles into what you eat. Glass fixes it.
Swap first · about 600 g of plastic a year
Cling film → lidded containers or beeswax wraps
Cling film is single-use plastic in direct contact with food. A plate on a bowl does the same job for free.
High priority · about 400 g of plastic a year
Plastic lunch box → stainless steel
Steel lunch boxes last for years, go in the dishwasher and don't stain or crack.
Worth doing · about 100 g of plastic a year