What Happens if You Put Metal in a Microwave Oven?

Perhaps most of us are aware that subjecting metal to microwave energy would generate sparks or worse. But why does this happen, and are there exceptions? It covers all that’s needed in understanding why metal doesn’t naturally go well with microwaves, what could happen if you were to microwave metal, and some surprising facts on microwave-safe metals.

What Happens if You Microwave Metal?

When microwaves interact with metal in a microwave, the outcome can be risky. Unlike food, which absorbs microwaves to create heat, metal reflects microwaves, often resulting in sparks or “arcing.” These flashes of electricity are caused when metal disrupts the even distribution of microwave energy. This can lead to potential fire hazards or even damage to the microwave itself.

Why No Metal in a Microwave?

The fundamental principle of heating the food inside a basic microwave is based on the heating up of the water molecules present, so that they vibrate and generate heat.

However, metal objects do not absorb the microwave energy well, instead, they reflect the microwaves back and forth within the cavity. Therefore, this leads to faulty heating and sparking, which may cause damage. In contrast, you can use microwave silicone safely, as it absorbs heat without reflecting microwaves, making it a safer option for microwave use.

Can You Put Metal in a Microwave?

In general, putting metal in a microwave is not safe, with some exceptions. Here are some types of metal and their behavior in a microwave:

• Aluminum Foil: Often used to shield food areas from heat in ovens, aluminum foil is usually not safe in microwaves, as its thin structure tends to spark.
• Steel and Iron: These metals reflect microwave energy, which can lead to significant sparking, especially around sharp edges.
• Aluminum Pans: Although thicker than foil, aluminum pans can still spark when microwaved due to thin sections and sharp edges.

Why Do Some Microwaves Have Metal Racks?

It might seem contradictory, but some microwaves are designed with a metal rack inside. These racks are meant to interact safely with the microwaves and are usually fixed so that arcing is mitigated. Nonetheless, when using a microwave with a rack made from metal, make sure you adhere to the guidelines as indicated in the manual since improper setting or contact with food can also cause sparking.

What Metals Are Microwave Safe?

While most metals are unsafe, certain microwavable metal containers are specifically designed for safe use:

• Microwavable Steel: Some steel containers are engineered with coatings or shapes that prevent arcing. These should always be labeled as “microwave-safe.”
• Metal Racks: As mentioned, racks built into microwaves are specifically designed to avoid sparking.
• Specially Treated Aluminum: In commercial settings, certain treated aluminum containers are considered microwavable metal containers, although this isn’t common for home microwaves.

Is It OK to Put Metal in the Microwave?

If you’re wondering can you put metal in a microwave, the short answer is no—unless it’s labeled as microwave-safe. Even if metal doesn’t spark right away, cumulative exposure can still damage your microwave.

What Happens If You Microwave Metal?

If you happened to microwave metal, it can produce sparks or even occasional flashes. These sparks occur because the microwave energy, having been reflected and accumulated on the surface of the metal, causes hotspots and creates a risk of fire. Repeated exposure of a microwave to metal can damage its internal parts, especially the magnetron, which is responsible for generating microwave energy.

Microwave Safe Metal Containers

Certain microwavable metal containers are specially designed to avoid arcing. These containers are more common in commercial kitchens, where metal packaging needs to withstand microwave energy without sparking. Always check for a microwave-safe label before using any metal container.

Is Aluminum Safe in Microwave?

Using aluminum in the microwave is generally not recommended. However, specific aluminum containers made for microwave use are engineered to minimize arcing. If you’re in doubt, avoid aluminum unless it’s clearly marked as safe.

Common FAQs About Metal in Microwaves

Can you microwave steel?

Unless labeled as microwavable steel, steel should be avoided in the microwave due to its reflective properties.

Does putting metal in a microwave damage it?

Yes, metal in a microwave can cause arcing, which may damage internal parts and shorten the microwave’s lifespan.

What happens to metal in a microwave?

Metal in a microwave generally leads to sparking, arcing, and sometimes even fires.

Can you microwave aluminum foil?

No, aluminum foil is highly reactive in microwaves and can cause immediate sparking.

Why do some microwaves have metal racks?

These racks are specially designed to be safe, although they should be used with the microwave’s manual instructions to avoid misuse.

Is it ok to put metal in the microwave?

Only if it is labeled microwave-safe. Most metal objects are unsafe due to arcing risks.

Conclusion: Avoiding Metal in a Microwave

In general, you should avoid using metal in a microwave oven except for some very specific circumstances. Microwave-safe items, like some racks or special containers, are all right. The best bet to be safe and avoid costly damage is with the use of non-metallic dishes, like glass, ceramic, or microwave-safe plastics.