What is smoke made of?

“Dracarys.” All Daenerys had to do was to say that magic word, and set everything ablaze. Thousands of innocent people were slaughtered as the Mad Queen sat atop Drogon, and go all-evil and burn King’s Landing to the ground. Siblings and lovers Cersei and Jaime Lannister were both crushed, bringing their secret in the deep tunnels beneath their kingdom.

R.R. Martin’s Game of Thrones series and other fantasy world is not complete without a fire-breathing dragon. But if dragons were real, how did they get that steaming, fiery breath? It has yet to be answered.

At the moment, we are sure that fire has three basic needs: something to ignite, fuel to keep it burning, and oxygen, which it interacts with fuel as it burns. Among these ingredients, oxygen is the easiest to find. It is present in water, in plants, and animals, and in much of the solid material that makes up the Earth. It comprises 21% of our planet’s atmosphere, giving us the air we breathe.

You want to breathe some fresher air, so you go out for camping. You start a nice fire for your barbecues and marshmallows. The fire was going nice until it has burned down the wood and left “hot glowing embers.”

The fire produces a lot of heat, but it makes no smoke at all. You now toss dried twigs onto the fire, and you notice that it creates a lot of smoke as it heats up. Suddenly, it bursts into a flame, and the smoke is gone. If you have been around a lot of camping, this little scene is quite familiar to you.

Why do some fires seem to have more smoke than others? What are the elements of smoke?

Smoke is a collection of tiny solid and liquid particles. Visible smoke is mostly composed of carbon, oil, tar, and ash, although it can contain hundreds of different chemicals and fumes.

Smoke happens when there is not enough oxygen to burn the fuel completely. When fuel is completely burned, water and carbon dioxide are produced, and the tiny unburned particles compose a smoke.  Each particle is so small to be seen by the naked eye, but they come together, and we see them in the form of smoke.

There are four things that we can find in a piece of wood.  There is water (freshly cut wood contains a lot of water while dried wood contains less), volatile organic compounds (compounds that evaporate when heated), carbon (soot), and ash (the non-burnable minerals in a tree’s cells).

When you put a piece of wood on a fire, the smoke you see is the volatile hydrocarbons evaporating from the wood. Hydrocarbons start vaporizing at 300 degrees Fahrenheit (149 degrees Celsius). At higher temperatures, these compounds burst into flame. Once they start burning, there is no smoke because these hydrocarbons turn into carbon dioxide and water.

This explains why you don’t see smoke from a charcoal fire or the “hot glowing embers.”

Charcoal results from heating wood to high temperatures without oxygen. One way is to take some woods and put it in a sealed box of clay and heat it to about 1000 degrees Fahrenheit (538 degrees Celsius). This process removes all the volatile organic compounds, leaving carbon and ash, and lighting the charcoal burns pure carbon. The carbon then combines with oxygen to produce carbon dioxide, and what is left at the end of the fire is the ash (minerals).

The inhalation of smoke can be irritating and toxic, depending on the fuel. For example, burning plastics produces poisonous gases like hydrogen monoxide and carbon monoxide. The inhalation of smoke is one of the primary causes of death in victims of indoor fire. As it happens, nearly 75% of the victims die of smoke rather than the fire.

Moreover, smoke contains flammable compounds. And with increased oxygen, these can ignite either through open flames or by their temperature. Smoke also fogs visibility, making people disoriented during an evacuation. It often results in death as people get suffocated while finding their way out of the building. Besides, smoke can leave widespread stains and smells that are difficult to remove.

We have to be quick to put out smoke to prevent a fire; it’s like you stop a gossip to avoid a fight.