Why Do Candles Explode? Stay Safe with Our Guide

Have you ever wondered why glass jar candles can become a fire hazard? It may seem like a rare occurrence, but the truth is that burning wax can cause serious damage and injuries if not handled properly. Understanding the reasons behind wax fires and candle explosions is crucial for preventing them from happening in your home or workplace.

Candles are typically made of wax and have a wick that burns to produce light. However, improper burning can cause the flame to come into contact with fuel or oil from the wax, leading to an explosion. This type of explosion can be dangerous, especially if the candle is not in a glass container or jar with proper vents.

We will also give examples of times when candle explosions have occurred and links to case studies for further reading. By understanding the fire hazard and potential wax fire caused by burning wax, you can enjoy the ambiance of candles without putting yourself or others at risk. However, it’s important to take necessary precautions to prevent oil fire accidents.

The Science Behind Candle Explosions

Candles have been a part of human civilization for centuries, providing light and creating a relaxing atmosphere. However, they can be dangerous when the burning wax turns into molten wax and becomes fuel for the flame. This danger is increased when candles are placed in a glass jar, as the heat can cause the jar to break and spread hot molten wax.

Combustion, Oxygen, and Heat

Combustion occurs when the wick of a candle is lit and melts the wax surrounding it, which serves as fuel. As the wax melts, it vaporizes and releases hydrocarbons into the air. These hydrocarbons mix with oxygen in the air and ignite due to heat from the flame, potentially leading to candle fires. However, if the candle is contained in a glass candle holder, any exploded candle will be contained within the glass.

The Role of Vaporized Wax

When a candle burns inside a glass jar, there is no problem of an explosion occurring as long as the fire triangle is not disrupted. However, if vaporized wax is trapped inside the jar and mixes with oxygen in the air, pressure builds up until it reaches a critical point where it can cause an explosion. In case of an emergency, pouring water over the candle can help solve the problem.

The Size of Wick Matters

The size of a candle’s wick plays a crucial role in determining whether or not an explosion will occur. If a wick is too large for its container or too close to its sides or bottom, it can cause too much heat buildup that will lead to an explosion. This explosion can result in fire, molten wax, and burning wax splattering onto nearby surfaces, including glass containers.

On the other hand, if a candle flame is too large due to an overfilled container or an oversized wick, it could cause candle fires and pose a serious candle safety hazard. Additionally, if the candle wax melts too quickly or unevenly, it could also contribute to candle fires. Conversely, if a wick is too small for its container or has been trimmed too short before lighting it up again after use, there won’t be enough heat generated during combustion which could lead to incomplete combustion leading to carbon deposits on your walls or ceiling.

Wax Reaching Its Flash Point: The Reason Behind Exploding Candles

What is the flash point of wax?

The flash point of wax is the temperature at which it can ignite and cause combustion, which can lead to exploded candles and candle fires. Different types of wax have different flash points, affecting their likelihood of candle flame ignition. This is an important consideration for candle makers to ensure the safety of their products. For example, soy wax has a lower flash point than paraffin wax, making it more susceptible to candle flame ignition and potential candle fires.

How does overheating or overburning a candle increase the risk of explosion?

When a candle burns, it creates a pool of molten wax around the wick. If this pool becomes too hot, it can reach its flash point and ignite, causing a fire hazard. Overheating or overburning a candle can increase the risk of reaching its flash point by causing the wax pool to become too large or too hot. To prevent accidents, it is best to place candles in a jar or glass container and keep them away from water sources.

What are some other causes of exploding candles?

Aside from overheating or overburning, there are several other causes that can lead to exploding candles, such as glass breakage, fire hazards, water damage, and jar defects.

  • Cracks in the glass candle jar or container can allow fire and heat to escape, which can cause the surrounding area to become too hot and pose a risk of water damage.
  • Adding foreign objects such as glitter or dried flowers to the candle inside a glass jar can create air pockets that trap heat and cause a fire. To prevent this, it’s important to keep a container of water nearby in case of any accidents.
  • Using a wick that is too large for the size of the candle in a glass jar can create an excessive amount of heat and cause a fire explosion. It is important to always have water nearby to quickly extinguish any flames.

Can exploding candles be prevented?

Yes, there are several steps you can take to prevent your candles from exploding in a glass jar and causing a fire. One of the most important steps is to never leave a burning candle unattended and always keep it away from flammable objects. Another important step is to place the jar on a flat, heat-resistant surface and avoid using too much water when extinguishing the flame. By following these precautions, you can enjoy your candles safely without worrying about any potential hazards.

  • Always follow manufacturer instructions for burning your candles.
  • Keep your candles away from drafts and flammable objects.
  • Trim your wicks regularly to prevent them from becoming too long and causing a dangerous candle fire. This is important advice for candle makers as it helps to control the height of the candle flame and avoid excess candle wax melting and dripping.
  • Use appropriate sized wicks for your candle size.
  • Avoid adding foreign objects to your candles.
  • Monitor your burning candles closely and extinguish them if they begin to smoke excessively. Always place your candles in a glass jar to prevent fire hazards. Keep water nearby in case of emergencies.

What should you do if you experience an exploding candle?

If you experience an exploding candle, it is important to act quickly to prevent fire, glass damage or injury. Consider using water or a jar to contain the situation.

  • Extinguish the candle immediately.
  • If the container filled with hot water, do not touch it until it has cooled down to prevent any risk of exploded candle or candle fire.
  • If there is a fire, use a fire extinguisher or call the fire department. Adding water may worsen the situation.
  • Ventilate the area to remove any fumes or smoke.

Hot Candles and Water Don’t Mix: Reaction with Water

Candles are a popular way to create ambiance, relax, and add warmth to any setting. However, have you ever wondered why candles can explode? It’s important to know that pouring water on a hot candle can cause it to explode due to thermal shock. Here are some reasons why:

Pouring water on a hot candle can cause it to explode due to thermal shock.

When a candle burns, the heat from the flame melts the wax and creates a hot wax pool around the wick. If you pour cold water onto this hot wax pool, it will cause the temperature of the wax pool to decrease rapidly. This sudden change in temperature causes thermal shock, which can lead to an explosion.

Steam generated by pouring water on a hot candle can also create pressure inside the container, leading to an explosion.

When you pour water onto a hot candle, steam is generated instantly. The steam created by pouring water on a hot candle takes up more space than liquid water does because of its gaseous state. This means that when steam is created inside a container holding the candle (like a glass jar), it creates pressure that builds up until something gives way and explodes.

It’s important to avoid using water as a way of extinguishing candles.

Water is not an effective method for extinguishing candles because it can make things worse instead of better. When you pour water onto burning candles, it splatters droplets of hot wax all over everything nearby. These droplets can ignite other objects or even people close by if they’re wet with flammable liquids like alcohol or gasoline.

Instead of using water as an extinguisher for candles, try using baking soda or sand instead. Baking soda works well because it releases carbon dioxide when heated, which smothers flames by removing oxygen from the air around them. Sand works similarly but doesn’t release gas when heated.

Alternatives to Glass Jars: Choosing Safer Candle Containers

Why Glass Jars are Not the Safest Option for Candle Containers

Glass jar candles have been the most popular type of candle for years. However, they pose a significant safety risk due to their propensity to shatter during an explosion. When a candle explodes, the glass jar can break into sharp pieces that can cause serious injury or damage to property.

There are several reasons why glass jars are more likely to shatter during a candle explosion than other materials like metal or ceramic:

  • Glass is brittle and does not bend or flex like other materials. This means that when pressure builds up inside the container, it is more likely to crack and break. However, it is important to note that using glass containers for candle fire can be dangerous.
  • Glass has a lower melting point than metal or ceramic, which means that it can melt and deform at lower temperatures.
  • Glass jars typically have narrow openings and tight-fitting lids, which can create a vacuum effect that increases pressure inside the container.

Choosing Safer Candle Containers

If you want to reduce the risk of an exploding candle, consider using containers made from safer materials. Here are some options:

  1. Metal containers: Metal containers are sturdy and less likely to shatter during an explosion. They also have higher melting points than glass, which makes them more resistant to heat damage. However, metal containers may not be suitable for all types of candles since they can interfere with scent diffusion.
  2. Ceramic containers: Ceramic containers are another safe option for candle making since they do not shatter easily and have high melting points. They come in various shapes and sizes so you can choose one that suits your style.
  3. Terracotta pots: Terracotta pots make great candle holders since they absorb heat well and do not crack easily under pressure. They come in many sizes so you can use them for small votives or large pillar candles.
  4. Concrete containers: Concrete is a durable material that can withstand high temperatures and pressure. It also has a unique industrial look that can add character to your candles.
  5. Tin cans: Tin cans are another inexpensive option for candle containers. They have a rustic charm and come in many sizes so you can use them for different types of candles.

Choosing the Right Container Design

In addition to choosing the right material, you should also consider the design of your candle container. Here are some tips:

  • Choose containers with wider openings or no lids to reduce the risk of pressure buildup inside the container.
  • Avoid containers with tight-fitting lids since they can create a vacuum effect that increases pressure inside the container.
  • Look for containers made specifically for candles since they are designed with safety in mind and often have features like reinforced bottoms or heat-resistant coatings.

By choosing safer materials and designs, you can reduce the risk of an exploding candle and enjoy your candles without worry.

Simple Steps to Prevent Candle Explosions: Trim the Wick

Candles are a great way to create a warm, cozy atmosphere in your home. However, if not used properly, they can pose a serious safety hazard. Improper burning of candles can cause small fires that can quickly turn into larger ones. One common reason why candles explode is due to an overheated wick.

Trimming the Wick Regularly Reduces Soot Buildup and Prevents Overheating

When you burn a candle, it produces soot that accumulates around the wick and on the inside of the container. If left untrimmed, this buildup can lead to an overheated wick which could cause an explosion. By trimming the wick regularly, you reduce soot buildup and prevent overheating.

Keeping the Wick at ¼ inch Length Ensures Proper Burning

Keeping your candle’s wick at ¼ inch length ensures proper burning and reduces the risk of a candle explosion. When you light a candle with a long wick, it burns too hot and creates more heat than necessary for proper combustion. This excess heat can ignite any flammable material nearby or even cause an explosion.

Using a Wick Trimmer Can Make Trimming Easier and More Precise

Using scissors or nail clippers may seem like an easy way to trim your candle’s wick but it often results in uneven cuts that make it difficult for your candle to burn properly. A better option is using a specialized tool called a “wick trimmer.” It allows for precise cuts at just the right angle for optimal burning conditions.

The Rule of Thumb: Trim Your Wick Before Every Use

The best way to prevent candle explosions is by making sure your candles are always trimmed before use. As part of your routine maintenance, trim the wick to ¼ inch length before lighting your candle. This simple step ensures proper burning and reduces the risk of an explosion.

Candle Fire Extinguisher: Using Baking Soda

Candles are a popular way to create a cozy atmosphere, but they can also be dangerous. One of the biggest risks associated with candles is the potential for them to explode. Fortunately, there is a simple and effective way to extinguish a candle flame without causing an explosion: baking soda.

Baking Soda as a Fire Extinguisher

Baking soda is an excellent fire extinguisher because it releases carbon dioxide when heated. This gas displaces oxygen, which is necessary for combustion, and smothers the flame. Pouring baking soda on top of a burning candle will smother the flame, preventing it from igniting surrounding materials.

Using baking soda as a fire extinguisher has several advantages over other methods:

  • It’s safe: Unlike water or chemical fire extinguishers, baking soda won’t damage electrical equipment or leave behind harmful residue.
  • It’s easy to use: Baking soda is readily available in most homes and doesn’t require any special training to use.
  • It’s affordable: A box of baking soda costs just a few dollars and can be used multiple times.

How to Use Baking Soda as a Candle Fire Extinguisher

If you need to extinguish a candle flame quickly and safely, follow these steps:

  1. Grab your box of baking soda.
  2. Slowly pour the baking soda onto the top of the burning candle until it’s completely covered.
  3. Wait for the carbon dioxide gas released by the baking soda to smother the flame.
  4. Once the flame has been extinguished, wait for the wax to cool before attempting to move or dispose of the candle.

It’s important to note that while using baking soda is an effective way to put out small fires like those caused by candles, larger fires should always be handled by professionals from your local fire department.

Safe Placement of Candles: Avoiding Air Drafts, Vents, and Flammable Items

Candles are a great way to create ambiance in any room. They provide a relaxing atmosphere, warm lighting, and can even add a pleasant aroma to your home. However, it is important to remember that candles can be dangerous if not used properly. One of the most common questions people ask is “why would a candle explode?” The answer lies in the placement of the candle.

Placing candles away from air drafts or vents can reduce their exposure to oxygen and prevent overheating.

Air currents can have a significant impact on the behavior of flames. When you light a candle in an area with air currents, it creates an uneven flow of oxygen around the flame. This can cause the flame to flicker or burn unevenly, which increases the risk of overheating and potentially causing an explosion.

To avoid this situation, it’s best to place candles away from areas with high levels of air movement. This includes near open windows or doors where there may be drafts or near vents where there may be forced airflow. By keeping your candles in still air environments, you reduce their exposure to oxygen supply and minimize their chances of overheating.

Keeping candles away from flammable items like curtains or paper can prevent fires caused by explosions.

Candles are often made from wax that contains flammable materials such as paraffin oil or beeswax. When these materials come into contact with other flammable objects like curtains or paper towels, they can ignite easily and cause fires that could lead to explosions.

To prevent this situation from happening, always keep your candles away from flammable objects like curtains or paper towels. It is also important to ensure that any loose clothing or hair is kept clear of the flame when lighting candles.

Avoid placing candles in high traffic areas where they could be knocked over accidentally.

Accidents happen all the time, and it’s important to take steps to prevent them from occurring. When candles are placed in high traffic areas like hallways or on tables where people frequently walk by, they can be easily knocked over accidentally.

To avoid this situation, always place candles in areas where they are less likely to be bumped or knocked over. This includes placing them on sturdy surfaces that are not easily moved and away from areas where pets or children may play.

Staying Safe While Enjoying Candles

In conclusion, candle explosions can occur due to various reasons such as the wax reaching its flash point, reaction with water, and unsafe placement. To prevent candle explosions, it is important to trim the wick regularly, choose safer containers, and avoid placing candles near air drafts or flammable items. Using baking soda as a fire extinguisher can also be helpful in case of emergencies. By following these simple steps and staying cautious while enjoying candles, you can minimize the risk of accidents.


Q: Can all types of candles explode?

A: No, not all types of candles are prone to explosions. However, any candle can potentially explode if proper safety measures are not taken.

Q: Is it safe to leave a candle burning overnight?

A: It is generally not recommended to leave a candle burning overnight or unattended for an extended period of time.

Q: How often should I trim the wick?

A: The wick should be trimmed to 1/4 inch before each use to prevent excessive flame height and potential fires.

Q: What should I do if a candle explodes?

A: If a candle explodes, immediately extinguish any flames and evacuate the area. Seek medical attention if necessary.

Q: Are there any eco-friendly alternatives to traditional candles?

A: Yes, there are many eco-friendly options available such as soy-based candles or beeswax candles that emit fewer toxins into the environment.

Q: Can I reuse candle jars for other purposes?

A: Yes, empty candle jars can be cleaned and repurposed for storage or decoration purposes. However, make sure to remove any remaining wax residue before reusing them.

Q: Are scented candles more likely to explode than unscented ones?

A: Scented candles are not necessarily more likely to explode than unscented ones. However, scented candles may contain additional chemicals that could potentially be harmful if not used properly.