What Happens to Candle Wax While Burning?

 variety of candles burning

Source: New Africa/Shutterstock.com

Burning a candle causes the scented solid wax to melt away and evaporate slowly. But have you ever given much thought as to where it goes? Homesick dives into the science behind combustion, exploring precisely what happens to candle wax. Plus, we answer a few more of your burning questions regarding safety and offer tips on how to preserve your candle as long as possible.  

Candle Wax Combustion

Candle wax, or paraffin, is made up of a chain of carbon atoms surrounded by hydrogen atoms. Combined, it creates hydrocarbon molecules which can burn completely. This is why the wax close to the flame ultimately melts into liquid.

Essentially, the heat from the flame vaporizes the wax’s hydrocarbon molecules, reacting with the air’s oxygen. As the wax vaporizes and is consumed, the wick draws more of the liquid wax, using a scientific force known as capillary action, where a porous material defies gravity using adhesion, cohesion and surface tension. In other words, so long as your California candle’s wax is still in contact with the capillary action-absorbing wick, the flame will consume the wax, leaving no ash or even residue.

Furthermore, since light and heat radiate from the flame, some of the combustion’s energy (roughly one-quarter) is emitted through the heat. In turn, this heat maintains the reaction. It vaporizes the wax so it can continue to burn and melt, maintaining the supply of fuel until there’s either 1) no wax left or 2) not enough heat to melt said wax.     

Moved Out of SoCal But Missing Home? Order a California Candle to Cure Your Homesickness

The Wax Combustion Equation

While the chemical equation can fluctuate due to certain variables, such as the type of wax used (ours is soy-based, for example), it’s generally as follows: 

C25H52 + 38 O2 → 25 CO2 + 26 H2O

In simple terms, heat causes a reaction between hydrocarbon and oxygen, which produces carbon dioxide, water and energy, or the heat and light. When burning a candle, you might notice the air still feels dry, even though water is technically being released. This is due to the temperature increase which allows air to hold more water vapor. 

homesick chicago candle

Worried About Inhaling Wax? Don’t Be!

At this point, you might be wondering, “If the wax essentially evaporates, does that mean we are inhaling it?” Not exactly.

When you burn a candle, the only thing released into the home’s air is carbon dioxide and water. While a steadily-burning, teardrop-shaped flame offers efficient combustion, a flickering flame can cause a fluctuation, visible by smoke wisps or soot, which is carbon. But even a flickering flame is nothing to worry over. While it indicates incomplete combustion, the vaporized wax of your orchard-like Apple candle doesn’t travel far at all and is centered only around the flame. It’s completely safe! 

Through an at-home experiment, you can actually see the wax vapor! All you need is two candles. Lighting one candle, allow the wick to begin vaporizing the wax. Extinguishing it, hold it somewhat close to the other candle’s lit flame. At this point, you should be able to watch the flame jump and travel along with the wax vapor, relighting the previously extinguished candle. And that’s science, folks!   

Give Your House a Crisp Smell with Our Apple Candle

While using a paraffin wax candle is safe, paraffin itself is made from petroleum, which is a gasoline by-product. According to a 2009 study, burning paraffin wax releases toluene, a potentially dangerous chemical. While some disagree with the study’s reliability, even a minuscule use of the gasoline by-product petroleum can be harmful to the earth, if not ourselves. Instead, use a plant-based wax, like an eco-friendly soy waxlike that used in Homesick candlesthat offers a carbon neutral, renewable and sustainable resource. Now that’s something to feel good about! 

 candle snuffed wick

Source: Haggardous50000/Shutterstock.com

Smokeless Flames and Smooth-Melting Wax

While candle wax is meant to literally evaporate, don’t let it go entirely to waste. Be sure to take advantage of the full 60- to 80-hour burn times on your Homesick candles. Learn how to burn a candle all the way down by creating a steady, teardrop flame that doesn’t flicker and wastes less wax along the way. That way, you can enjoy your favorite scent for a long time!