---
title: "Can you microwave plastic bags? It depends"
description: "Only bags sold as microwave or steam bags — sandwich and freezer bags are not rated for it. What actually happens, what goes wrong, and what to do instead."
url: https://atoneplace.net/can-you/microwave-plastic-bags/
site: "At One Place"
---

# Can you microwave plastic bags?

**It depends: Only bags sold as microwave or steam bags — sandwich and freezer bags are not rated for it.**

Bags designed for microwave steaming are made of a film tested for the temperature and usually have a vent built into the seam. Ordinary zip-top storage bags are polyethylene designed for cold storage; they soften near boiling and have not been tested for hot food contact. Grocery carrier bags and bin liners are never suitable. A sealed bag of any kind builds pressure, which is why every microwave steam bag tells you to leave a corner open or to stand it upright with the vent clear.

## How to do it properly

1. Use bags explicitly sold for microwave steaming
2. Leave the vent or one corner of the seal open
3. Stand the bag on a plate so a leak does not reach the cavity floor
4. Open it away from your face — the steam inside is at 100 °C

## What goes wrong

- A sealed bag inflates and bursts
- Cold-storage films soften against hot fatty food
- Printed or coloured bags are not food-contact rated at heat

## Other options

- Steam vegetables in a covered bowl with a splash of water
- Use a vented microwave steamer, which is reusable

## Other "can you microwave" questions

- [Can you microwave styrofoam?](https://atoneplace.net/can-you/microwave-styrofoam/) — It depends — Only if the container is labeled microwave-safe, and most takeout foam is not.
- [Can you microwave aluminum foil?](https://atoneplace.net/can-you/microwave-aluminum-foil/) — No — No — foil reflects microwaves and the edges arc, which can start a fire.
- [Can you microwave plastic containers?](https://atoneplace.net/can-you/microwave-plastic-containers/) — It depends — Only ones labeled microwave-safe — cold-storage tubs are not among them.
- [Can you microwave eggs?](https://atoneplace.net/can-you/microwave-eggs/) — It depends — Beaten or pricked eggs, yes. A whole egg in its shell will explode.
- [Can you microwave Tupperware?](https://atoneplace.net/can-you/microwave-tupperware/) — It depends — Yes, if that specific piece carries the microwave-safe symbol on its base.
- [Can you microwave paper plates?](https://atoneplace.net/can-you/microwave-paper-plates/) — It depends — Plain white paper plates are fine; anything with metallic trim or a foam layer is not.
- [Can you microwave metal?](https://atoneplace.net/can-you/microwave-metal/) — No — No — metal reflects microwaves, arcs at edges, and can damage the oven or start a fire.
- [Can you microwave breast milk?](https://atoneplace.net/can-you/microwave-breast-milk/) — No — No — microwaves create hot spots that scald a baby even when the bottle feels cool.
- [Can you microwave takeout containers?](https://atoneplace.net/can-you/microwave-takeout-containers/) — It depends — Only if the container is marked microwave-safe — most are not, and metal-handled ones never are.
- [Can you microwave cardboard?](https://atoneplace.net/can-you/microwave-cardboard/) — It depends — Plain dry cardboard is usually fine briefly; anything with glue, staples, wax or foil is not.
- [Can you microwave glass?](https://atoneplace.net/can-you/microwave-glass/) — It depends — Yes for ordinary heatproof glass; no for leaded crystal, and never straight from the freezer.
- [Can you microwave water?](https://atoneplace.net/can-you/microwave-water/) — It depends — Yes, but very clean water can superheat and erupt when you move the cup.

## Common questions

### Can you microwave plastic bags?

Only bags sold as microwave or steam bags — sandwich and freezer bags are not rated for it.

### What happens if you microwave plastic bags?

A sealed bag inflates and bursts Cold-storage films soften against hot fatty food Printed or coloured bags are not food-contact rated at heat

## Related pages

- [Can you microwave styrofoam?](https://atoneplace.net/can-you/microwave-styrofoam/)
- [Can you microwave aluminum foil?](https://atoneplace.net/can-you/microwave-aluminum-foil/)
- [Can you microwave plastic containers?](https://atoneplace.net/can-you/microwave-plastic-containers/)
- [Can you microwave eggs?](https://atoneplace.net/can-you/microwave-eggs/)
- [Can you microwave Tupperware?](https://atoneplace.net/can-you/microwave-tupperware/)
- [Can you microwave paper plates?](https://atoneplace.net/can-you/microwave-paper-plates/)
- [Can you wash pillows?](https://atoneplace.net/can-you/wash-pillows/)
- [Can you wash sneakers in the washing machine?](https://atoneplace.net/can-you/wash-sneakers/)
- [Can you recycle pizza boxes?](https://atoneplace.net/can-you/recycle-pizza-boxes/)
- [Can you reheat rice?](https://atoneplace.net/can-you/reheat-rice/)
- [Can you recycle plastic bags?](https://atoneplace.net/can-you/recycle-plastic-bags/)
- [Can you recycle batteries?](https://atoneplace.net/can-you/recycle-batteries/)

## Sources

- US Food and Drug Administration — FDA (https://www.fda.gov/) [Public domain (US Government)]