Can You Microwave Stainless Steel Lunch Box? What will happen if you do so!

People are aware that metal can’t go in the microwave, but still, sometimes they get confused when it comes to the question: Can you microwave stainless steel lunch box?

No, You can not microwave stainless steel lunch boxes because they are not microwave-safe and are not meant to be used inside the microwave.

It is not recommended to use any stainless steel object in the microwave; instead, you could use a microwave-safe container for reheating purposes.

Doing so can cause arcing on the lunchbox, and you will probably see sparks inside the microwave.

Arching and sparking in itself is not a big deal, but that doesn’t mean you should altogether avoid this fact.

Using stainless steel in the microwave can cause damage to the appliance, and there is also a potential risk of fire if you do not pay attention while putting a stainless steel bowl or lunchbox in the microwave.

Why can’t I microwave Stainless Steel Lunchboxes?

Firstly you should not try to microwave a stainless steel lunch box because the food inside the box will take much longer than usual to heat up as the heat waves can not pass through the metal surface.

Stainless steel is a form of metal, so the electromagnetic waves in the microwave can’t penetrate the thick metal surface.

Due to this phenomenon, the electromagnetic waves coming from the magnetron get reflected or bounce back from the stainless steel and may leave an electric discharge layer on the surface of the stainless steel lunch box.

The spark you see inside the microwave occurs due to this reason.

If there are frequent arcing issues and sparks in the microwave, there are high chances that the microwave can stop working due to damage made on the inside.

Besides sparking, as the microwaves can not pass through the stainless steel, the lunchbox itself will get so hot that you may burn your hand if you grab it directly.

Also Read: Why the outside surface of microwave gets hot

What would happen if I microwave a stainless steel lunch box

When microwaving a stainless steel lunchbox, it’s possible that you’ll damage your appliance and even end up breaking it down.

Yes, it’s true that in some cases, nothing really happens, and people get away without any issue, but it doesn’t mean you should also try it.

Check Out: Is it okay to put things on top of my microwave?

There are incidents when a fire hazard took place because of putting a stainless steel bowl or lunchbox inside the microwave by thinking it is okay.

In short, here’s what could happen –

  • Fire – There are high chances of a fire hazard if you recklessly microwave a stainless steel lunchbox in the microwave.
  • Sparks – Little sparks will be formed over the stainless steel object surface as the heat waves can not penetrate them.
  • Your lunchbox would be ruined – Putting the stainless steel lunch box in the microwave will ruin your lunch box. You don’t want that do you?
  • Microwave can get Damaged – Frequent sparks can result in the permanent failure and damage of your microwave.

What alternatives can you use?

There are many lunch boxes and containers available in the market that are microwave-safe. You could use them as an alternative that is safe and appropriate for reheating purposes.

The containers or objects that have microwave-safe mention are preferable for using inside the microwave rather than guessing and trying to put stainless steel bowls, lunch boxes, etc.

Related Post: Is a burnt microwave-safe to use?

In fact, some metal containers are suitable for use in microwaves, but that is seen rarely in the market.

If you are using a microwave-safe lunch box, then it should be perfectly fine as the material is specifically designed for heating food.

So your best bet will be to find microwave-safe or microwave-friendly cookware and containers and use them without worrying about aching, fire, or any issue in general.

Also Read: Is it Okay to use a microwave with peeling paint

How long can I microwave a stainless steel lunch box?

I wouldn’t recommend you microwaving a stainless steel lunch box in the first place unless you are looking for some trouble.

However, if you use the stainless steel lunch box in the microwave, the food will be heated at a much slower pace as the waves can not pass through the lunchbox, resulting in wastage of both time and electricity.


I hope you have liked reading this article about why can’t you microwave stainless steel lunch boxes, what risks are involved and what alternatives could you use.

It is not safe to put a stainless steel lunch box in the microwave even if someone says they’ve tried it and got away without any problem.

The chance of fire hazard is there if you microwave stainless steel or any metal, and your appliance could be at risk of getting damaged.

So, don’t put a stainless steel lunchbox in the microwave as you are risking damage to yourself, your microwave, and even getting into a fire hazard situation.

Instead, choose microwave-safe containers that are designed explicitly for reheating purposes. They will help you achieve faster heating and ensure your safety of food and microwave.