Is Linseed Oil Flammable? − Dangers, Precautions, And Solutions!

No doubt that linseed oil is a blessing when it comes to wood finishing or painting. It provides a stunning glow and finesse to the art piece, whether on canvas or wood. 

However, there are some concerns pertaining to it. The most common one being ‘Is linseed oil flammable?

Yes, unfortunately, it is. When oxygenated and as it reaches the flashpoint of flammability, the oil may start a fire spontaneously. But don’t worry now because there’s more to the story. 

Here, we will explore not only the flammability of the oil but also the precautions of using it and increasing its fire resistance. Take a few minutes back from the woodworking and read this; you won’t be disappointed!

Is Linseed Oil Flammable 1

Is Linseed Oil Fire-Resistant? − Improving Fire Resistance

Nonetheless, with its beauty, linseed oil comes with flammable characteristics. But don’t worry; there are ways to improve its fire resistance. 

Don’t you want to know how? Let’s find out.

Add Fire Retardant Additives

Adding fire retardant substances is definitely one of the most effective ways to increase the oil’s ability to resist fire. 

These additives work by reducing the flammability character of the linseed oil and limiting the spread of flames when there’s a fire. Such examples are ammonium phosphate, antimony trioxide, aluminum trihydrate, etc. 

Apply Fire-Resistant Coatings

Another way to work this out is to use a fire-resistant coating on surfaces treated with linseed oil. These coatings act like shields to keep the linseed oil from ignition. 

Two of the fire-resistant coatings include intumescent coating and ceramic coating. 

Oxygen Reduction

Of course, linseed oil won’t burn on itself and needs oxygen for combustion. So, what if you limit the oxygen amount? 

You can do this by storing the oil in an airtight container or using a sealant on surfaces treated with it. 

Increase Linseed Oil Viscosity

You can also increase the oil’s viscosity to boost its fire resistance ability. This implies that you can add thickeners to linseed oil, making it dense. The thicker the oil, the less likely it is to catch or spread the fire.

Try Other Coating Options

If nothing else works or sounds like a good option, you might just need to switch to a coating other than linseed oil, which is more resistant to fire if the fire is the main issue. 

A few such examples are epoxy, silicone, or polyurethane coatings. 

Can Furniture With Linseed Oil Catch Fire?

Can Furniture With Linseed Oil Catch Fire

As you already know, linseed oil is commonly used as a finish material for wooden furniture. But it’s also highly flammable. And that’s where the concern comes from. So, can furniture with linseed oil catch fire?

Honestly, the answer is no! Yes, even with the high probability feature of the oil, it’s quite impossible for furniture with a linseed oil finish to simply catch fire out of nothing. 

That’s because, in the case of a furniture finish, a very thin layer of linseed oil is used as a coating. However, you must clean it off after the finish application using balsamic turpentine and a moist cloth. 

Now, there are a few things to consider when using linseed oil on furniture. 

Penetration in the Wood

It penetrates deeply into the wooden surface when it is applied, where it hardens later on and forms a protective layer. 

Undoubtedly, this layer is highly flammable and can easily catch fire if exposed to flames or heat. 

Faster Oil Oxidation 

Due to the fast oxidation property of the oil, if you’re using rugs for applying the furniture finish, there are a few things to do afterward. If more oil is left in a pile of soaked rags, it will eventually combust.

Reason Behind the Combustion 

If the linseed oil has a larger surface area and the insulating effect of the rag, it lets the heat build up over time rather than dissipate. 

In this case, you must dispose of the rags or paper towels with the oil in them properly. And if there’s a spill of linseed oil anywhere, you must clean it up as soon as possible. 

It’s likely to wash it up and then wash it with strong soap and water. Make sure there are no leftovers to worry you out!

Is Linseed Oil Toxic When Heated?

Typically, linseed oil is of great use, which you already know, whether it’s in producing paints, varnishes, finish material, or other coatings. But do you know what happens when linseed oil is heated?

Releases Volatile Compounds 

Although pure linseed oil poses almost no threat to human health, when heated, it’s oxidized. Thus, it releases an odor and some harmful volatile organic compounds. 

The primary compound is carbon dioxide, followed by ethane, ethylene, ketones, acetaldehyde, carbon monoxide, etc. These can cause respiratory irritation, headaches, and other health issues if inhaled in higher amounts. 

Maintaining Appropriate Temperature Is Essential 

Knowing the exact temperature range at which linseed oil is a safety concern is important. This depends on a few factors, such as the heating method, the quantity of oil heated, and the duration of the process. 

Generally speaking, linseed oil will probably start to release fumes at temperatures even as low as 100 degrees C or 212 F. Yes, the boiling point of water. However, with an increase in temperature, the fume concentration increases, and so does the risk of exposure to harmful VOC levels. 

Brings High Potential of Toxic Vapors 

It is also important to remember that indirect heating of the oil can also carry the danger of exposure to hazardous gas. Toxic vapors can also be released during heating materials that have been treated with linseed oil, even for wood!

What Experts Say

Research conducted by a reputed chemical agency revealed that the boiling point of linseed oil ranges from 317-320 degrees C or 640 degrees F, depending on the specific combustion of the oil. At these temperatures, the quantity of VOCs in the vapor can be high enough to endanger human health. 

How Do You Extinguish Linseed Oil Fire?

If you’re new to using highly flammable linseed oil, you must also know how to extinguish a fire quickly and safely if the oil lets a fire loose. Binge on to know for your safety!

How Do You Extinguish Linseed Oil Fire

Step 1: Cut off Oxygen Contact

Your first step would be to cut off any oxygen supply. You can do this by covering the fire with a fire blanket or any non-flammable material like a damp cloth or metal lid. With no oxygen for combustion, the fire will eventually fall out. 

Step 2: A Fire Extinguisher Is a Good Option

If a large fire breakout takes a larger surface area, your best deal is to use a fire extinguisher because, in this case, a fire blanket won’t do the work. Use a Class B fire extinguisher, which is made to put out flames caused by combustible liquids like linseed oil. 

If you’re sure the fire has been extinguished, sweep the extinguisher back and forth while aiming it at the fire’s base.

Step 3: Do Not Use Water

Some people in haste or anxiety may start using water, but DO NOT! Water can cause the fire to spread and even start up an explosion. 

Besides, remember that water doesn’t work on fires caught from flammable liquids, and it mostly results in causing a bigger fire. 

Step 4: Evacuate the Area Immediately

If you cannot extinguish the fire in any way, or if the area of the fire is too large, simply evacuate it immediately and contact the fire department. Remember not to fight a large fire that spreads vigorously on its own. 

Step 5: Prevent Any Future Fire Occurrences

If you’re done handling the fire situation, there are a few things you can keep in mind for future precautions. Be mindful to store linseed oil in a cool and dry place, away from any heat source. 

Also, when applying linseed oil on any surface, ensure proper ventilation and dispose of rags or brushes used to apply it properly. 

Is Water-Soluble Linseed Oil Flammable?

Before we answer this question, don’t you want to know the difference between regular linseed oil and water-soluble linseed oil? 

Linseed oil is derived from flax seeds and is traditionally used in painting and woodworking as a finish or oil paint medium. It is a slow-drying oil and highly durable, and resistant to water and damage. 

Of course, let’s not forget its high flammability property.

On the other hand, water-soluble linseed oil is a modified version of linseed oil that has been formulated to be soluble in water. It is created by adding an emulsifying agent to the oil, allowing it to mix with water. 

Pros of water-soluble linseed oil include easier cleanup and quick drying. Besides, water-soluble linseed oil is less toxic and has lower VOC emissions than traditional linseed oil.

But what about the flammability of water-soluble linseed oil? 

While traditional linseed oil has high flammability, water-soluble linseed oil is said to be less combustible since it contains fewer solvents overall. 

However, you cannot neglect that water-soluble linseed oil is still combustible and must be handled carefully. For instance, you must keep it away from heat sources, flames, and the possibility of sparks. 

And also, keep it in a cool and dry place, away from sunlight. You must carefully follow the manufacturer’s recommendations when using water-soluble oil because the drying time can vary depending on the brand. 

Besides, before applying any additional oil coats, remember to let it dry completely. 


1. What is the flashpoint of linseed oil?

With extended studies and experiments on linseed oil, it has been found to ignite at 93 degrees C or 200 degrees F with oxygen contact. This is the flashpoint of linseed oil. 

2. What time does it take for linseed oil to ignite spontaneously?

With exposure to air, linseed oil will catch fire rapidly in seconds when the flashpoint heat is applied. However, it also depends on a few other factors like the quantity of oil, the duration of carrying out the heating process, etc. 

3. What causes linseed oil to combust?

The problem with linseed oil is that it doesn’t dry up like paint through evaporation. Instead, it dries through the chemical process of oxidation. 

Wrapping Up!

Well, now you know that linseed oil is flammable, and the flammability content is quite high too. But should it stop you from adding a beautiful finish layer to your furniture or painting using oil? Not at all! 

You can still use the oil, but all you need to do is follow the precautions mentioned.

Here’s some advice, if you’re applying the oil on woodwork, remember to apply only a small amount at a time because it can take even days to dry out, increasing fire possibilities fully. 

You definitely don’t want that! Work safe, folks, till next time!