Can a Candle in a Glass Jar Start a Fire? (Quick Facts) 

Candles can be decorative, eliminate odors in the home, and even create an atmosphere with subtle lighting. But it’s important to remember that lit candles are open flames. That makes any lit candle a potential fire hazard.

Burning a candle in a glass jar is probably your safest bet. You don’t have to worry about wax melting onto the surface below. But you still have to be cautious about what’s surrounding the glass jar if you want to prevent a fire. 

Read on to learn how to safely burn candles in a glass jar by following the tips listed below.

Can a Candle in a Glass Jar Start a Fire

Is Candle Safety Really All That Important?

The goal of this article is not to alarm you but to bring light to the importance of candle safety. Once you’re done reading it, I hope you feel armed with the right information to keep you and your family safe.

According to the U.S. Fire Administration, “in less than 30 seconds a small flame can turn into a major fire.” That’s how quickly fire can spread.

Each day there are at least 20 reports of home fires that are caused by candles. Two percent of all home fires are due to candles, leading to deaths, injuries, and property damage.

Learning how to safely burn candles can prevent negative events such as these from occurring.

Is It Safe to Burn a Candle in a Glass Jar?

For the most part, it’s safe to burn a candle that’s in a glass jar because they’re non-flammable and non-porous. 


Glass isn’t combustible, so you don’t have to worry about a glass candle container catching fire. This is why materials like plastic and wood aren’t used as candle containers.  

Unglazed clay, like terracotta, ends up soaking up all the wax, extending the boundaries of the candle. This poses a fire hazard because the entire container becomes combustible. Unlike glass, porous materials such as this literally add fuel to the fire. 


You shouldn’t have any problems with the jar itself so long as it has a thick, flat base and sturdy side walls. 

A thick base prevents the surface beneath the lit candle from overheating or the candle from burning too hot.

You want the jar to have a flat bottom so that it won’t tip over, causing the flame to spread. 

If the side walls of your glass jar are too thin, then it won’t hold high levels of heat. Thin walls can crack if they get too hot. This is why using wine or martini glasses as candle vessels is frowned upon.

Remain Cautious

Even glass made to withstand high heat can crack if in certain conditions. Therefore supervision is equally important. When you’re in the same room as the candle, you’re in a better position to prevent a fire from spreading. 

Candle Safety Tips to Prevent House Fires 

The most effective guard against fires caused by candles is understanding candle safety. This video outlines basic safety tips to follow when lighting candles.

Candle Safety Tips with Fire Inspector Marsha McCurdy Adell

Don’t Leave Candles Unattended

One of the worst things you can do is light a candle, and then leave the room. Whether it’s a pillar candle or a container candle, you’d be putting your safety at risk.

Sometimes I hesitate to blow a candle out if I notice that a full wax pool hasn’t yet formed. It can be tempting to leave the candle lit in order to prevent tunneling. But this is a bad idea.

Before lighting a wide candle that would need to burn for hours before the wax fully pools, make sure you’ll be in the room for that long. If you have to leave the room, it’s better to blow out the candle and risk tunneling than to risk your life or property damage.

Keep Distance

Three out of every five home fires were caused by combustible material coming too close to the candle flame. Flammable materials should be kept at least 12 inches away from an open flame.  This includes curtains, hanging planters, cabinets, apparel, bedding, paper, and such. 

Flat Surface

In addition to a flat base, you always want to burn your candle on a flat surface. An angled or bumpy surface could cause the candle to tip over.

Don’t Burn Your Candle Until the End 

Most candle companies will advise you to leave half an inch or so of wax at the bottom of your container. For some of the more expensive candles especially, it can be difficult to not burn every drop of wax.

Your container might get too hot and crack if you burn the candle all the way down. Not only will wax pour all over the place, the flame will travel with the wax, which poses a fire risk.

Allow Your Candle to Fully Cool

If you notice that you’re at the end of a candle, allow it to fully cool off before disposing of it. 

Even after a flame goes out, there might still be an ember that can ignite flammable objects surrounding it in the garbage can, which poses a fire hazard.

There are ways that you can reuse the wax or upcycle the container. But if you have the tendency to toss candles out when you’re done, wait until the wax has hardened.

Never Relocate a Burning Candle

Similarly, never move your candle once it’s lit and wax begins to pool. In most instances, the container will be too hot.

Upon picking it up, the heat can cause you to lose your grip and drop the container. This of course could potentially start a fire.

Don’t Allow Candles to Burn Overnight

If you’re drowsy, avoid lighting a candle. Get some rest instead. Thirty-seven percent (37%) of home candle fires start in the bedroom.

Falling asleep with candles burning accounts for 10% of home fires and 12% of deaths resulting from those fires.

Candles do not burn out on their own. Anything can happen while you’re sleeping, like the jar overheating, and then cracking. 

Keep yourself and others safe by blowing out candles before going to bed. Four hours is usually the maximum amount of time for a candle to burn.

Install Smoke Alarms

Accidents can happen even after you’ve taken all the necessary precautions. Installing smoke alarms can offer a warning that something is wrong. Not to worry, though, typical smoke generated by your candle flame, won’t likely set off your fire alarm.

There should be a smoke alarm inside and outside all sleeping areas.

Make sure your smoke alarms are operational by testing them once a month.

Keep Candles Away from Children and Pets

I’m sure you’ve heard this warning before but it bears repeating.

Flames are alluring and many children and pets are intrigued by them. Seeing a candle on a low surface might entice your child or pet to investigate. But while doing so, they might harm themselves or cause the candle to get knocked over.

Avoid these mishaps by keeping candles out of their reach.

Protect the Surface Below

Just as important as not having flammable objects hanging over an open flame is making sure your candle burns on a heat-resistant surface.

It might be tempting to place your candle in a sturdy upholstered ottoman or some other flammable surface. Nope, not worth it. Stick to non-flammable or flame resistant surfaces only.

Return Damaged Containers

Never light candles that are in cracked or chipped glass jars. As the wax heats, the cracks can widen and extend beyond the initial rupture.  If the container was damaged when you purchased it, I would suggest returning the item to the store for a replacement.

If interested, the U.S. Fire Administration shared this candle safety checklist with additional tips that you can download and read.

What to Do If a Candle Catches Fire

Worst case scenarios are often the last thing we want to think about. But it’s important to have a plan in place so that you have an idea of what to do if bad things happen.

Fire Extinguishers

Smoke alarms alert you to a problem but fire extinguishers can prevent a fire from spreading once it starts. Your local home improvement or hardware store will likely have them in stock.

There are five different types of extinguishers that you can read about here to figure out which one is best for you.

You can get in touch with your local fire department to be trained on how to use and maintain them, which includes keeping the fire extinguisher charged so that it’s ready to use when needed.

Put a Lid on It

If possible, put a lid over the jar. Flames need oxygen to grow and a lid would prevent the flame from spreading.

Get Out of the House!

If the flames are growing too large to be doused out by a fire extinguisher or snuffed by a lid, then the safest solution is to get out of the house and call the fire department.

Grace Young

I love candles! I have personally tried over 100 brands of candles. The total burn time of these candles is over 5000 hours. I also talk about essential oil diffusers and reed diffusers. Essential oil diffusers and diffusers are also an important part of the scent in my home.

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