The microwave oven has become an indispensable appliance in most kitchens today. It provides a quick and convenient way to heat up leftovers or cook a wide variety of foods.
However, when using the microwave, it’s important to know what types of materials are safe to use and which ones should be avoided.
One common question is whether aluminum trays can go in the microwave. Let’s take a closer look at the facts.
Is Aluminum Microwave Safe?
Aluminum has some properties that make it risky to use in the microwave. It reflects microwave energy rather than absorbing it.
This can lead to problems, including:
- Uneven heating: food may cook unevenly or have cold spots since the aluminum doesn’t get hot.
- Sparking: Aluminum can cause sparks or arcing in the microwave, damaging the appliance.
- Burn hazards: Any metal edges or pieces that aren’t smooth could get extremely hot and cause burns.
So aluminum on its own is not considered microwave-safe. However, some aluminum trays have been specially designed to be used in the microwave when certain precautions are followed.
Special Microwave-Safe Aluminum Trays
Some trays are now made out of aluminum but have a special coating or finish that allows them to absorb microwave energy rather than reflect it.
These types of aluminum trays are labeled “microwave safe”. A few things to look for:
- Check any labels or packaging. It should clearly state the tray is microwave-safe and provide any special instructions.
- Look for a smooth or dull finish. Rough edges, sharp corners, or a highly reflective surface mean it’s not microwave-safe aluminum.
- No metal should be exposed. Any parts without the special coating could arc or spark.
As long as these guidelines are followed, this type of aluminum tray is designed to heat food safely in the microwave. But not all aluminum is created equal when it comes to microwave use.
Risks of Microwaving Regular Aluminum Trays
Any aluminum tray without a special microwave-safe coating is risky to use in the microwave, even for a short time.
Here are some of the potential dangers:
- Sparking or arcing: The metal can reflect the microwaves and cause electrical arcing inside the appliance. This can burn out the microwave’s magnetron tube.
- Fire hazards: Sparks can ignite food or paper products, leading to a fire. Even without sparking, the tray can get hot enough externally to ignite nearby items.
- Burnt food: Since aluminum doesn’t absorb microwaves efficiently, food will be unevenly heated and likely burned in spots.
- Aluminum melting: Thin aluminum can warp, melt, or scorch inside a microwave oven, damaging the appliance and making the metal tray unusable.
- Toxic leaching: Research shows aluminum exposed to high heat and certain acids or foods may leach toxins like aluminum oxide into food.
Any signs of arcing, smoke, or melting should be taken as a warning to stop microwaving immediately. The risks simply outweigh any benefits.
Safe Alternatives to Aluminum Trays in the Microwave
Thankfully, there are many materials that are totally microwave-safe.
Good options to use instead of aluminum include:
- Glassware: Glass food containers, plates, and bowls do not contain metal and won’t spark. Ensure any glass is heat-resistant.
- Ceramics: Ceramic plates, mugs, and bowls heat evenly and are non-reactive. Do not use ceramics with metallic paint or decorations.
- Paper plates and bowls: These are inexpensive, disposable, and heat food evenly, though they may not be as durable. Avoid paper products with any metallic glitter or lining.
- Microwave-safe plastics: Containers labeled “microwave-safe” won’t melt or leach chemicals when heated. Do not use any plastic not marked safe.
Stick to microwave-safe cookware and avoid any uncertainty around metals. When in doubt, apply the microwave litmus test: metals spark and reflect, plastics warm, and glass heats evenly. Play it safe when deciding what to microwave.
FAQs About Aluminum Trays in Microwaves
Still have some questions surrounding aluminum trays and the microwave? Below are answers to some frequently asked questions.
Is it safe to microwave aluminum foil?
No, regular aluminum foil should never be microwaved. It can cause electrical arcing, damage the appliance, or start a fire. The crinkly surface and thinness of the foil make it especially dangerous.
Any type of aluminum that is not labeled microwave-safe should be kept out of these ovens.
Aluminum cookie sheets or baking trays do not have special coatings, so they remain unsafe in microwaves.
The uneven, heat-conductive surface also increases the risks of overheating, burning food, and starting electrical sparks. Stick to microwave-safe cookware only.
What if the aluminum tray has a plastic lid? Is that okay?
Whether a plastic lid is on an aluminum tray or not, the bare metal parts could still lead to arcing or overheating issues.
Both the container and lid need to be rated fully microwave-safe before use in this appliance. The safest bet is to transfer food into microwave-safe dishware.
Is it safe to use aluminum foil to shield food when microwaving?
Using small pieces of aluminum foil to shield parts of food from overcooking is still risky. The foil edges may spark if they get too close to the oven walls or uncovered food.
It’s safer to use microwave-safe materials, like parchment paper or plastic wrap, to prevent overcooking.
Can you put frozen foods in aluminum trays into the microwave?
No, frozen foods in aluminum trays should not go directly into the microwave. Aluminum does not heat evenly, which could lead to burned spots.
The safest way to microwave frozen foods in aluminum is to thaw them first and transfer them to microwave-safe dishware.
What happens if aluminum is accidentally microwaved?
Stop the microwave immediately if you see arcing or sparking from the aluminum inside. This can damage the appliance and make it unsafe for further use until it is repaired. The metal may also be melted or burned.
Avoid any food that has been heated, as dangerous leaching can occur. Let the oven fully cool before removing anything to prevent burns.
The Bottom Line
At the end of the day, microwave ovens and aluminum do not mix well. The properties that make aluminum an ideal metal for so many uses are the exact same ones that can make it hazardous inside a microwave.
Special coatings allow some aluminum trays to be microwave-safe, but it’s essential to closely follow instructions.
For anything short of a specially designed tray, keep the aluminum out and opt for microwave-safe alternatives to heat foods quickly and safely.
Follow the manufacturer’s directions, and when in doubt, leave the aluminum trays out of the microwave.
Hi, I’m Julie, the passionate foodie and founder of Juliesfamilykitchen.com. I created this blog out of a drive to prove someone wrong, and then I realized how much I truly enjoy cooking and trying new recipes. In my free time, when I’m not running around after my kids or spending quality time with my partner, you can usually find me in the kitchen experimenting with new dishes.