6 Everyday Materials That Could Wreck Your Microwave

Microwaves make heating food incredibly fast and convenient, but they’re not compatible with everything. Using the wrong materials can cause fires, release toxic chemicals, or damage your appliance.

In Lagos alone, the Fire Service responded to over 1,600 fire incidents in 2024, with about 75% attributed to carelessness, including appliance use.

Here are six materials you must avoid putting in the microwave:

1. Aluminum Foil

Metal reflects microwave radiation instead of absorbing it, which can cause sparks, fires, or even damage your oven. Aluminium foil is particularly dangerous because its thin edges can quickly ignite.

A safety advisory from appliance manufacturers and kitchen safety experts warns that using aluminium foil in a microwave is one of the leading causes of microwave-related fires worldwide.

2. Plastic Containers

Many plastics release harmful chemicals like Bisphenol A or Phthalates when heated. If a container isn’t labelled “microwave-safe,” it could melt, leach toxins into your food, or warp beyond reuse.

Even if a container is labelled “microwave-safe,” it might only refer to the container’s ability to withstand heat, not its safety for human health.

3. Styrofoam

Styrofoam, or polystyrene, is not heat-resistant. When microwaved, it can melt and release styrene, a possible carcinogen, into your food.

The Lagos State Government has banned the use and distribution of Styrofoam due to environmental and health concerns.

The ban is in response to the negative impacts of Styrofoam on the environment, including its non-biodegradable nature and potential harm to wildlife and human health. 

4. Paper Bags

Unless they are microwave-labelled, paper bags are a fire hazard. Some may also release toxic fumes or catch fire due to uneven heating.

 A review of microwave-related fires by home appliance repair technicians in Lagos noted an uptick in incidents involving paper packaging.

5. Takeout Containers with Metal Handles

Some disposable containers include metal components or foil linings, especially handles or seals. These can create arcs or sparks.

6. Grapes and Whole Eggs

Though it may sound odd, certain foods like grapes can create plasma sparks, and eggs (in the shell) can explode due to built-up steam pressure.

Conclusion

Microwave ovens are a modern kitchen essential, but they require caution and awareness. Always verify that any container or food item is microwave-safe before heating. Avoiding these common mistakes can protect your health, your home, and your appliances. When unsure, use glass or ceramic alternatives.