There’s not a kitchen in the land without some vegetable oil on the shelf. It’s the most popular way to fry. Whether you’re going for deep fried chicken or some mushrooms to accompany your salad, vegetable oil makes it easy to prepare these dishes. However, should we be concerned about the use of vegetable oil and is it a major fire hazard that could end up with us in, literally, hot water?
Vegetable oil is not technically flammable, but it can catch fire in common cooking. The flashpoint of most types of vegetable oil is around 600 degrees Fahrenheit (315 Celsius), which means it is not classified as a flammable liquid by OSHA.
There are different types of vegetable oil that are commonly used. Let’s take a look at what you need to know when it comes to vegetable oil and fire.
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Also read: What Makes Something Flammable?
What Is Vegetable Oil?
Vegetable oil is a catch-all term for oils that have been extracted either from vegetable seeds or, sometimes, from parts of a fruit.
While there is often an assumption that vegetable oil is healthier than animal fats, in reality, they are a mixture of fats too and some vegetable oils are every bit as unhealthy for consumption as animal fats.
When people use the term “vegetable oil” in the kitchen, they mean any vegetable fat which has stayed liquid at room temperature. As you’d expect, the majority of these oils are completely edible.
Humanity has been cooking with these oils for at least 8000 years! Olive oil production has been demonstrated in both Israel and Palestine at around 6,000 years BC! Along with culinary usage, the oil would also have been used to fuel lamps.
One of the valuable properties of vegetable oils is that they can be heated to a significantly higher temperature than the boiling point of water. This makes them very useful for frying, which cooks the outside of the food rapidly while raising the temperature of the interior to kill off any bacteria or germs that live inside.
It is worth noting that you can’t use any old vegetable oil for cooking. Those chosen for use in the kitchen are chosen specifically because they have a high smoke point (that is the temperature at which they start to smoke).
The flashpoint is the temperature at which a liquid releases enough vapors to catch fire in the presence of a spark or naked flame. It is not the auto-ignition point (the temperature at which the substance will catch fire without the need for a flame or spark).
The average flashpoint temperature of vegetable oils is around 600 degrees Fahrenheit (315 Celsius).
Well, this is very hard to say. There are a lot of different vegetable oils out there including, peanut, soybean, canola, coconut, rice bran, palm, safflower, sunflower, cottonseed, mixed oils, etc.
This variety means that you can’t assume the flashpoint of any given oil and it’s a good idea to look it up. However, as a loose rule of thumb – the majority of vegetable oils will have a flashpoint in the range of about 600 degrees Fahrenheit.
That’s why vegetable oil is not considered flammable. It burns at nearly 400 degrees above the 199.4 degrees Fahrenheit mark.
Note: If something burns below 199.4 degrees Fahrenheit in the presence of a flame or spark it is considered to be a flammable liquid by OSHA.
Some will argue that cooking oil vapor could lead to a fire as it would be more flammable. While they are correct in thinking this, cooking oil doesn’t tend to evaporate at temperatures below the flashpoint in any significant quantities.
You can’t burn what isn’t there and thus, cooking oil remains highly combustible, but not technically flammable.
Can It Ever Burn?
Yes, vegetable oil can burn.
In fact, cooking is the cause of 49% of all home fires (and frying with oil make up a huge part of those fires).
The warning sign that oil is about to become a problem is when it starts to smoke. That’s evidence that it’s at the smoke point. That usually means it is getting close to the flashpoint, where it can catch fire.
Particularly if you’re cooking over a gas flame, this is the point when you might release enough vapor for it to catch fire.
Once oil catches on fire, it’s challenging to extinguish, and you need to make sure you use an extinguisher that is classified to put out oil fires. Using anything else is highly dangerous and could see you spread the fire rather than put it out.
Look at what happens when water is put on hot vegetable oil, in slow motion:
Also read: Will a Fire Extinguisher Ruin an Oven?
Can These Oils Spontaneously Combust?
Yes, vegetable oils can spontaneously catch fire.
Though they won’t catch fire in a well-sealed and properly stored container. They can, however, catch fire if they are dried up on rags.
Organic oils, including vegetable oils, have self-heating properties that can lead to spontaneous combustion and fire. It’s important to clean such rags or dispose of them properly.
Also read: Is Grease Flammable? It Depends…
What About Olive Oil?
No, Olive Oil is not flammable, it is technically combustible. However, it can certainly catch fire and was once a popular fuel for lamps.
It can even be used as a fire starter, take a look:
Also read: Is Olive Oil Flammable? Can it Catch Fire?
Canola oil can catch fire, but like most vegetable oils it is not technically flammable.
The flashpoint is around 600 degrees Fahrenheit, so it doesn’t qualify as a flammable liquid.
Peanut oil is not flammable, by definition, as it has a flashpoint of 600 degrees Fahrenheit.
Coconut oil can catch fire more easily than most vegetable oils, but it is still not technically flammable.
The flashpoint is about 563 degrees Fahrenheit.