When you first hear the word “tar,” what is the first thing that comes to mind? If I were to guess, I’d say the black or dark brown slimy, sticky, and strong-smelling liquid. So you are correct in a way, but when I say “tar,” I am not referring to a single compound.
Tar can be made from different things and used for various things, including household and beauty products. It is usually made from the destructive distillation of wood, petroleum, coal, or peat and looks like a product from hell. But the burning question is – is tar flammable?
Is Tar Flammable?
The answer to that question depends on the type of tar we are talking about. In its natural form, tar is extremely flammable. It doesn't need extreme conditions to catch on fire. Tar can create a fire hazard – and is extremely dangerous when inhaled.
Tar typically gives off fumes (or vapors), which can easily catch fire in the presence of oxygen. However, as I said, the ability and rate at which tar ignites depend on its kind.
What Is Tar?
Now that you know that tar is more than that slimy black liquid, you’re probably wondering what it is. Tar is a thick liquid substance formed from any hydrocarbon source (compounds made of hydrogen and carbon). It contains hydrocarbons and some percentage of free carbon, and it’s created through a process called “destructive distillation.”
Tar also comes in three major forms: coal, mineral, and wood. Each is used for distinct purposes. For example, coal tar is derived from the distillation of coal and is used for road pavement and as a topical medication.
Meanwhile, wood tar is derived from wood carbonization from pine, oak, and beech trees. It is usually used as fuel and wood preservative. For a long time, Europe mass-produced tar to prevent wood from rotting and to waterproof ships and sailing vessels. However, it is produced in smaller units and used in traditional boats today.
On the other hand, mineral tar is derived from shale rocks. Mineral tar is naturally occurring and is highly adhesive. This mineral substance has many uses.
Tar comes in solid, liquid, and diluted forms and can be a helpful ingredient in things you may not expect – such as anti-dandruff shampoos, food spices, sauna scents, and flavoring for alcohol and candies.
How Flammable Is Tar?
Tar catches on fire easily if exposed to a naked flame or spark. Also, tar can spontaneously combust if left on rags or exposed surfaces – this is why safely disposing of rags used in cleaning tar is essential.
Additionally, tar fumes are likely to burn or catch fire when exposed to a naked flame. Once that happens, the tar from which the fumes are produced will follow suit.
Tar is a viscous liquid, but when it catches fire, it becomes less dense and starts foaming up. Then, it will quickly swell and pour out of the container, depending on the quantity.
Tar doesn’t explode, but it is a dangerous fire hazard because it tends to expand when burning, potentially causing a big fire upon contact with other combustible materials. As someone who’s worked with construction companies, I have had my fair share of tar fire experiences. For instance, I’ve witnessed coal tar that caught fire after some intense hours under the sun, and it was a fiery sight.
The high flammability of tar is because it comprises a mixture of organic chemicals such as ketones, alcohols, and hydrocarbons. Yet, this substance’s flammability is what makes it very useful in making roads – provided it is used properly.
Does Burning Tar Stick?
If you’ve ever laid roof or pavement tar (messy work, by the way), you’d know how sticky tar usually is. Now imagine what happens when it burns.
Tar is composed of small molecules that stick to one another when burned, making a tar-induced fire challenging to extinguish. When tar burns, it creates a great deal of heat and smoke, which, when inhaled, can pose serious health risks. Furthermore, tar gets sticky when it burns because it contains a high concentration of tar oils.
What Types Of Tar Are Flammable?
All types of tar are flammable. Generally, the flash point of tar is about 102 degrees Celsius or 215.6 degrees Fahrenheit. However, this may differ based on the form (liquid, solid, or vapor) and type (coal, wood, or mineral) of tar.
One of the most flammable types of tar is coal tar. It produces fumes easily ignited by heat, flames, or sparks. It has a flash point of >200 degrees Celsius and will decompose at 400 degrees Celsius to release toxic and flammable fumes.
Vapors are more dangerous because they are denser than air and may travel to a source of ignition, forming explosive mixtures with air.
Dry tar is also highly flammable. It reacts violently when exposed to a strong oxidizing agent. On the other hand, roof and road tar are not as flammable as coal and dry tar.
Road tar is one of the least flammable types of tar, but that does not mean you should bring fire near it. Road tar can also combust and catch fire. Roofing tar is also less flammable but will combust if fumes and vapors are present.
Can Inhaling Tar Cause Cancer?
Tar is a carcinogen. It can coat the insides of the lungs, leading to permanent damage over time. This can result in lung cancer, emphysema, and other health problems. Tar fumes may not be the most toxic, but you should never inhale them – not on purpose, at least.
You particularly want to avoid inhaling tar if you have asthma or other respiratory problems; it can set off a severe attack. Don’t be too scared, though. You will be fine if you only inhale tar at a minimum and not for a long time. However, if you inhale large amounts of tar over a long period, you should seek medical attention.
Final Thoughts
Is tar flammable? Absolutely! Tar, in any form, is flammable – it is only the level of flammability that differs from one type of tar to another.
Tar will catch fire if brought near a naked flame or any heat source. It poses more fire hazards than many other substances. More so, tar expands when it combusts, and the vapor it produces travels farther and faster than air. As such, it can come in contact with combustible materials in minutes, creating a serious fire outbreak.
