If you’ve felt the sticky liquid oozing from injured tree barks – maybe a Christmas tree, then you know what sap is.
Tree sap, otherwise known as tree blood, is one of the fascinating characteristics of trees. It is responsible for providing the tree and its branches with nutrients.
Additionally, the sap isn’t just useful to trees; it’s useful to humans in different ways – it serves as syrup, antiseptic, and more. So, it is important to understand how to handle it safely.
One of the most important safety questions around tree sap is – is tree sap flammable? Can it harm you if you are not careful?

Is Tree Sap Flammable?
Well, the short answer is yes. Tree sap is a highly flammable substance comprising flammable gas and oil. It can catch fire when exposed to high temperatures or other heat sources.
More so, if not extinguished on time, tree sap can explode and cause a lot of damage. Tree sap can ignite when spilled on floors and items in the presence of fire or naked flame.
What Is Tree Sap (Tree Blood)?
Tree sap is that sweet, thin, gummy, and watery substance produced by maple, eucalyptus, fir, and pine trees. These trees produce sap through photosynthesis, passing through the xylem channels and phloem to supply energy to new buds. The sap is crucial in many organisms’ life cycles because it contains essential nutrients for survival.
Tree sap contains organic compounds and essential nutrients such as amino acids, lipids, sugars, and minerals.
This thin liquid is also a food source for animals and helps make biofuel. Tree sap is often called ‘tree blood,’ illustrating the liquid substance that gushes from trees.
How Flammable Is Tree Sap?
Tree sap can easily catch on fire, especially when exposed to high temperatures or ignition sources.
There is something called a flash point when it comes to flammable substances. It represents the lowest temperature a substance has to reach before it bursts into flames. While many flammable substances have a flash point, tree sap does not have a particular flash point temperature value.
This means tree sap is highly flammable and will ignite regardless of temperature. I recently went camping and had difficulty setting up a fire for my family. Luckily, I found some pine sap and only had to leave it under the sun for a few minutes before it caught fire, allowing us to have a huge campfire. Too bad we were out of marshmallows.
Tree sap is also highly flammable because it’s sticky – its sticky consistency allows the fire to spread quickly.
Part of why it’s so flammable is because it consists of flammable oil and gas. Leaving it long enough close to a heat source in an open container will cause it to explode.
Tree sap is so flammable that it will ignite even when the tree branches are slightly damp.

How Can You Test For A Tree Sap’s Flammability?
Not all tree saps are flammable, so you need to know what tree sap is flammable, especially when going camping. However, I don’t want you going on a wild goose chase when you need some fuel for your campfire.
Sap from pine, maple, fir, birch, and eucalyptus trees, to mention a few, is flammable. While this information is important, it isn’t exhaustive of all the trees with flammable sap. So, you must know how to test tree sap for flammability, especially if you camp often.
Thankfully, there are simple ways to test the flammability of tree sap.
The simplest of these methods is the paper test. Put some sap on a piece of paper and roll the paper. Ensure you wear gloves so your hands do not come directly in contact with the sap. If the paper becomes black, the sap is flammable; if it doesn’t, it’s not.
Also, you can test the flammability of the sap by brushing it between your fingers. Rubbing the sap between your fingers will cause the sugars to crystallize. Watch out for when the crystals break. If the broken crystals produce smoke, the sap is flammable.
The smoke produced when the crystals break demonstrates the ability of the tree to combust and catch fire quickly.
How Do You Collect Tree Sap?
Tree sap may be flammable, but that does not rule out its uses. For instance, like I often do, you can use tree sap to make a fire in the woods or make syrup at home. Even if you don’t need the sap, learning how to collect it is still bonus knowledge for you, so let’s remember:
- Start by finding a tree with sap, such as a birch tree, maple tree, or pine tree. Choose a mature tree.
- Next, drill a hole upward in the tree and chop about six inches of the bark using your axe. Keep chopping until you see the sapwood. The sapwood is clean, not brown or orange. If you see brown or orange sapwood, fungi and yeast have colonized the sap – find another tree.
- When you have located clean sap, use alcohol to sterilize your spout and fix it into the hole you dug.
- Next, attach your bucket to the tree on the ground and stand back as sap flows into it. Once you hit the sapwood, the sap would naturally pour from the wounds and into the bucket.
- You may need about two to three weeks to collect sap from trees, although some produce more rapidly than others. So, ensure you visit the wounded tree regularly to get rid of debris and collect ready sap.
Even if you don’t go camping regularly, tree sap can serve as glue, syrup (such as maple syrup), drinking juice, and a natural antiseptic. Whatever the case, these steps make it easy to obtain just enough sap.
Can Pine Tree Sap Start A Fire?
Pine tree sap is one of the most flammable tree saps and an efficient fire starter. I use pine tree branches and sap for campfires anytime I go camping, and they’ve always been effective! Even when slightly damp, the pine branches always produce the same effect.
You can also achieve this through a few steps. For example, to start a fire using pine tree sap, find a suitable pine tree and chop a few layers off its bark. Keep chopping until the sap starts oozing, then use a stick to collect and light the sap.
As mentioned earlier, pine tree sap is handy if you go camping or are stuck in the woods. For instance, if your tinder is wet and you need to start a campfire, you can get some pine tree sap, and you’re all set. You can also use pine sap to create a burning torch – you only need a long stick and fabric.
To do this, take the long stick with one end wrapped with fabric. The fabric serves as a wick. Next, dip the covered end of the stick with the sap you collected and leave it to dry. When it is dry, light it up with a match. This makeshift torch burns slowly and for a considerable time.

How Can Tree Sap Ignite?
Anything can cause tree sap to ignite, from sparks to high temperatures or heat. However, the most common way tree sap ignites is through contact with an open flame – say, a cigarette or campfire. Tree sap can also catch fire by friction from rubbing two pieces of bark together.
Meanwhile, tree sap can sometimes ignite when the sun heats it to combustion. So now you know why forest fires can happen so suddenly. Sometimes, it was not caused by human activity.
Tree sap burns with a bright flame and emits lots of smoke when it catches fire. It also contains carbohydrates like sugar, and this is what makes it so flammable. When carbohydrate is heated, it breaks down and releases energy through light and heat – hence, the easy fire.
What Do You Do If You Are In A Tree Sap Fire?
Tree sap can catch fire when you least expect it, especially when the sun is scorching. According to the National Park Service, tree sap is highly flammable and will catch fire quickly if ignited. So, if caught in a tree sap fire, you must act quickly for your safety and that of the woods.
You can extinguish pine resin or sap fire by dousing the fire with water from a bucket or hose. If you do not have water, you can use sand – sand smothers the flame, especially if it’s a small fire. If the fire is more than you can control, use a fire extinguisher, aiming it at the base of the flames, not the top.
Final Thoughts
Is tree sap flammable? Yes! Can it start a fire? Yes! Is it dangerous? No, it isn’t. However, it can become a dangerous fiery tool when subjected to certain conditions.
But flammability is not the only characteristic of tree sap; it is also valuable for making food, beverages, and medicines.
Tree sap is generally safe for fuel if there is maximum supervision and proper handling. However, if you are using it, ensure you know the potential dangers and take precautions.