December 11, 2023

Every person needs to be ready for those disasters and shortages that life will throw at you. Naturally, a good way to be ready is to stockpile various goods and supplies in your home so you’ll have them when you need them.

cooking oil used a fuel for DIY candle

But somewhat ironically, that stockpile might be a threat in case of an accidental fire.

Many of the things that we accumulate in a quest for readiness can end up starting or accelerating a house fire, so you’ve got to know which ones will in order to better reduce this risk.

How about vegetable oil? Is vegetable oil flammable?

Vegetable oil is not flammable, but it will still catch fire and burn at a flash point of 600 °F (315 °C) or so. Vegetable oil is still a significant contributor to accidental fires when cooking. A large stash of vegetable oil can be a significant fire hazard, and should be stored accordingly.

Most of us have either experienced a cooking accident involving vegetable oil, or know someone who’s experienced such an accident.

It isn’t pretty, and mishandling a vegetable oil fire can make it 10 times worse in the blink of an eye, turning a small blaze into a raging inferno.

You want to know everything there is to know about the fire hazards posed by this type of oil and how to handle them, and I’ll tell you below…

Vegetable Oil is Not Technically Flammable

While it might seem counterintuitive to all common sense, vegetable oil is not technically flammable.

The scientific definition of flammability refers to a substance’s ability to ignite and burn in the presence of an ignition source under normal atmospheric conditions.

By this definition, vegetable oil isn’t classified as flammable because it won’t catch fire and burn at or near room temperature or when exposed to a small flame.

However, it’s essential to understand practical flammability. While vegetable oil isn’t flammable in the technical sense, it can and will catch fire and burn at high enough temperatures- temperatures that can be achieved in the kitchen!

This makes vegetable oil a good fire starter along with some tinder in a survival scenario. Veggie oil heated enough can spontaneously ignite without any external ignition source.

Does Vegetable Oil Ignite at Any Temperature?

Yes. Vegetable oil does not ignite just because it is hot or briefly exposed to open flame: It requires a specific heat threshold to catch fire, around 600 degrees Fahrenheit.

At this high temperature, the oil will spontaneously ignite and start to burn. This is why it’s crucial to monitor the temperature when cooking with oil carefully.

Overheating it can lead to a fire even without open flames or glowing heating elements. Be alert when working with vegetable oil for this reason, especially if you are frying with it!

Warning: You Must Never, Ever Use Water to Put Out a Vegetable Oil Fire!

If you learn nothing else from this article, learn this: never to use water to extinguish a vegetable oil fire. The reason for this is rooted in the basic principles of chemistry we all learn back in middle school.

Water and oil just do not mix; instead, when it comes into contact with the burning oil, it instantly turns into steam due to the high temperature, expanding rapidly.

This rapid expansion forces the burning oil upwards and outwards, causing the fire to spread quickly and violently in a giant column of flame and steam.

Furthermore, the steam can carry tiny droplets of burning oil, creating a dangerous ‘fireball’ effect. To put out an oil fire you must smother it or use an appropriately rated fire extinguisher.

Caution: A Spritz of Vegetable Oil Can Easily Ignite!

While we’ve discussed that vegetable oil in its normal liquid state isn’t technically flammable I should note that a spritz or mist of vegetable oil behaves very differently!

When vegetable oil is sprayed or misted into the air, the tiny droplets have a much larger surface area relative to their volume.

This larger surface area allows the oil droplets to heat up very quickly when exposed to a heat source. As a result, a spritz of vegetable oil can ignite far more easily and unpredictably than a pool of oil.

This is why extra caution must be exercised when using spray bottles of the stuff or vegetable oil “spritzer” products, especially near open flames or hot surfaces. This is a mistake you might only get to make once!

Does Vegetable Oil React with High Temperature?

Indeed, vegetable oil does react when exposed to high temperatures. The result is complex chemical changes occurring within the oil as the temperature rises.

Initially, the oil may begin to smoke and discolor. This is often referred to as the “smoke point”, which is the temperature at which an oil starts to visibly smoke and break down.

As the temperature continues to rise beyond the smoke point, the oil can and will ignite, leading to a fire.

Also note that the temperature, duration of heating, and the specific type of veggie oil used can influence these reactions. More on that in the next section…

Different Vegetable Oil Blends Have Slightly Differing Flash Points

“Vegetable oil” as it is popularly marketed is somewhat of a misnomer, if I am being kind, and outright lies if I am not: these oils are not directly obtained from vegetables but rather from seeds and occasionally fruit byproducts.

Examples include sunflower oil, canola oil, and palm oil.

These oils all have slightly different chemical compositions, resulting in varying smoke points and flash points.

Though not a huge issue since they all ignite near enough to 600 degrees F, it’s worth mentioning since precise cooking equipment like fryers might allow accurate temperature control.

Will Vegetable Oil Make a Fire Worse?

Absolutely, vegetable oil can seriously intensify an existing fire. Although it may not readily ignite when exposed briefly to an open flame or other high temperatures, its interaction with an already burning surface or accidental fire can lead to disastrous results!

The oil can serve as additional fuel for the fire, enabling it to burn hotter and longer. This can not only intensify the fire but also cause it to spread more rapidly as the liquid oil runs and spatters around the area.

Always handle and store vegetable oil carefully around heat sources or open flames to prevent these bad outcomes.

Is Vegetable Oil Reactive with Other Substances?

Generally, vegetable oil does not react hazardously with other substances that are found in typical households. In this context, “reacting” means creating an additional hazardous condition or increasing the risk of accidental fire.

Vegetable oil is chemically stable and doesn’t undergo dangerous reactions with common household substances.

However, it’s worth noting that combining vegetable oil with certain substances under specific conditions, such as high heat, can affect its properties and potentially its safety.

For example, mixing vegetable oil with water and heating it can lead to violent boiling and splattering as mentioned, posing a substantial burn hazard.

How Should You Deal with Vegetable Oil Exposed to Fire?

When vegetable oil catches fire, you’ve got to keep your wits and handle the situation carefully using the correct extinguishing method: panicking and splashing water on it is going to result in a bad, bad day.

For a vegetable oil fire (or other oil fire), you will need a Class B fire extinguisher (or ABC-rated one). This extinguisher rating denotes a unit or formula designed to deal with flammable liquid fires, which includes oils.

They usually work by creating a foam barrier that suffocates the fire, preventing oxygen from fueling the flames. Other than that, other safe methods include a metal lid or cover, fire blanket, or dry media like sand or baking soda.