There is the understandable perception that aluminum foil must be a fireproof material. After all, we use it all the time for cooking, so there can’t be a combustion risk there. On the other hand, there are all those horror stories about fires in microwaves due to foil. Then there are reports of people using foil for fireproofing home and even trees in wildfires. So, is foil actually fireproof?
Generally, foil is considered fireproof because many of its properties are extremely fire resistant. It is also true that in some cases, foil has the potential to help protect structures and trees in wildfires. However, that doesn’t mean that aluminum foil can’t catch fire in extreme circumstances, or that those microwave fire risks aren’t real.
There is a lot to unpack here to better understand the potential of aluminum both in fire protection and as a fire risk. We’ll start by looking at the use of aluminum in cooking and the pros and cons there. I want to highlight the fact that there are risk factors to be aware of.
Then we can look at the use of foil in fire protection and how this varies from the foil in our kitchen cupboards. I will also talk about some other foil products of note.
Is Aluminum Foil Combustible In An Oven?
Let’s start with the risk of using aluminum foil in an oven. This is something many of us will do because it is so often listed as a cooking instruction.
We can cover trays and dishes of food with this foil to keep the heat in and allow for a better result.
The heat resistance of the material is also helpful for safety in the kitchen as you aren’t going to burn yourself if you touch it coming out of the oven.
There are concerns that these foil wraps can cause sparks that would cause the oven to catch alight.
This is highly unlikely.
If you were to get this foil up to a temperature of 660 degrees Celsius, or 1,220 degrees Fahrenheit, it would catch fire.
But, no standard oven is going to get that hot. You would need a significant blaze to already be in progress for aluminum to burn.
While there is the potential that aluminum foil could cause an electric spark in an oven, it is highly unlikely and there is little chance of it doing anything to ignite the oven itself.
The bigger risk is if the oven isn’t clean and the spark ignites oil or food particle. But, again, this is unlikely.
More people are concerned about the risks of aluminum leaching into food than starting fires, but that’s a whole other discussion.
Why Is Aluminum Foil A Fire Risk In A Microwave?
The biggest fire risk when using aluminum foil in the kitchen is if you cook in the microwave. While aluminum foil is safe in the oven, we should never use it in the microwave.
The microwaves can react with the metal in the foil, and this will cause sparks.
These can be enough to cause fires within these smaller electrical devices, which can lead to a lot of molten plastic and the risk of bigger kitchen fires.
Is Aluminum Foil Combustible In A Fire?
Because it takes a lot for aluminum foil to catch fire, it is unlikely for it to incur any damage in contact with a low-level flame.
In fact, you can put a piece of foil in a flame and not do too much damage. The foil will come out blackened and discolored, which makes it look as though it has burned in the fire.
But, if you were to wipe this down you should find that the foil is in very good condition and unaffected.
Why Is Foil Used In Blankets?
Because of this reaction to fire, and the heat resistance of aluminum foil, there are some practical applications for aluminum foil outside of the home.
The heat resistance is why you see aluminum foil used in emergency blankets.
They are brilliant for insulation and preserving the body heat of those stranded in the wilderness and at risk of hypothermia. They are also light enough to pack for expedition trips.
Does the Fire Service Use Foil In Wildfires?
The other interesting consideration about aluminum and fires is that there is the potential for it to be of use in fire protection.
This sounds like one of those urban legends, but there is some truth to this. It all depends on the situation and the type of foil used.
There are a few cases of this happening in areas where wildfires are common. One example is that of the California fire department that came to the rescue of ancient redwood trees and wrapped their trunks in foil.
This foil acted as an essential barrier to stop these giants from becoming lost in the flames.
Of course, there are other forms of fire protection in wildfire situations, and the effective use of fire retardants can also help.
But, it makes sense to use this foil around specimens of significance like these redwoods. It could hold back the fire just enough to preserve them.
Can You Use Aluminum Foil To Protect Your House From Wildfire?
Yes and no. You can use the right type of foil barrier to provide some protection if you do so correctly. But, you can’t just use any old kitchen foil and expect the same results.
There are cases where homeowners have taken this idea of using foil to provide a similar barrier around their own trees and even their homes.
It sounds silly at first, but these barriers could be the ideal way to add an extra layer of protection.
It could be preferable to spraying materials with fire retardant or relying on ugly fire-resistant building materials like concrete.
Concrete and brick-built approaches may be the way to go for new builds in these vulnerable parts of California.
Also, I wrote an entire article on whether concrete is flammable. Click the link to check it out.
But, there still needs to be adequate protection for the older properties and any timber structures in the area.
This of course means protecting any historical landmarks that may be at risk of perishing in the flames.
In fact, firefighters once used this protective wrap to cover five historical cabins at the Placer Guard Station.
How Is Firefighting Foil Different From Kitchen Foil?
The problem is that these effective foil products in the fire service are a lot thicker than your average roll of foil.
They need to be if they are going to provide enough protection against the heat and ferocity of the flames. They can withstand a higher heat than kitchen foil and maintain their structure.
Typically, kitchen foil tends to be around 0.016mm thick, and even the more heavy-duty stuff is just 0.024mm.
This is perfect for cooking and other general applications because you can tear it and manipulate it with ease.
These thicker firefighting sheets are more like large blankets we can drape and tape around the structure. It is just as easy to use but works in a slightly different way.
This structure also means that they can act as personal fire shelters during wildfires, a bit like a more extreme version of those emergency blankets mentioned before.
Is Foil Paper Flammable?
It is important to note that when I talk about foil, I am talking about those 100% aluminum sheets of foil.
However, there are other products out there related to foil that have additional properties and materials that make them more hazardous.
One such product is foil paper.
This is something you will see a lot of in food packaging and crafts. One side of the paper has a thin metallic coating to offer a shiny reflective surface – we see it in papercraft and chewing gum wrappers.
But, the other side is paper, which means cellulose content that is liable to go up in flames.
Is Tin Foil Flammable?
You may see products referred to as tin foil rather than aluminum foil, depending on their origin.
The name tin foil comes from the fact that foil wrappers were originally made from tin, before the invention of the more lightweight and effective aluminum.
You can’t get this anymore.
So, “tin foil” is the same kitchen foil with the same great fire-resistant and heat-proof properties.
Is Foil A Fire Hazard?
To summarize, foil is not a fire hazard unless you make the mistake of putting aluminum foil over food in a microwave.
There aren’t the same risks when cooking with foil in the oven, and it has such a high ignition point that it is unlikely to catch fire. Instead of being a fire hazard, foil is actually pretty helpful for fire protection.
Firefighters will use heavy-duty foil blankets as protection in wildfires and wrap structures and trees to keep them safe.