Can You Burn Cardboard in a Fireplace?

With winter weather at its coldest, it's time to heat up your fireplace. However, you shouldn't just burn anything in your fireplace. With Christmas at an end, you probably have plenty of cardboard boxes leftover. This may leave you wondering if you can burn cardboard in your fireplace. To give you the most reliable answer possible, we scoured through several sources. See our findings below.

Although it may be tempting to burn leftover cardboard, you should stick to burning them outside. Since cardboard is treated with chemicals, you should never burn it in your indoor fireplace. 

Cardboard isn't the only material you should avoid burning in your fireplace. Read along as we discuss other items that could be dangerous when burned inside, what happens if you burn these items in your fireplace, and more. Without further ado, let's get into it!

A yellow bright flame arising from a fire of cardboard, Can You Burn Cardboard in a Fireplace?

Burning Cardboard in a Fireplace

When you look at all the cardboard boxes lying around your house, from pizza containers to shipping boxes, you may feel like you are just adding to the landfills by tossing them in the trash.

While this is true, you also should not burn these boxes in your indoor fireplace. If you really want to help the environment, you should try recycling your cardboard instead.

Burning cardboard and firewood in the fireplace

What Happens When Cardboard is Burned?

There are two separate reasons why you should not burn cardboard in your fireplace.

First, cardboard is treated with chemicals. When the cardboard is burned, those chemicals are released into your home. In return, you inhale the toxic fumes which could be dangerous for your health.

Unlike firewood, cardboard creates a lot of ash when it's burned. If you burn it inside your home, those ashes could float around and make a mess in the house. In severe cases, that stray ash could start a house fire.

What Should You Not Burn in a Fireplace?

Cardboard isn't the only thing you shouldn't burn in your fireplace. Many other products are chemically treated and shouldn't be burned indoors for various reasons.

Not only is burning cardboard and other trash harmful but it is also illegal in most states. This includes burning the items in fireplaces as well as outdoors.

The following are just a handful of materials not to put in your fireplace:

  • Christmas trees
  • Plastic
  • Trash
  • Unseasoned wood
  • Pressure-treated wood

Christmas Trees

Spruce branches burning in the fireplace after Christmas

Like boxes, it can be tempting to burn your Christmas tree in the fireplace once the holiday is over. After all, firewood is expensive, so why not chop up the Christmas tree and use it?

While this may sound like a good idea, doing so could be disastrous. Christmas trees contain a lot of water. Therefore, they create a lot of smoke when burned which means they will line the chimney with excessive amounts of soot and creosote.


Throwing a plastic bottle in a hot oven

You should never burn plastic products in your fireplace. Although there is little risk of stray ashes escaping, the fumes released could be toxic when inhaled. These toxins can also linger in your fireplace long after the plastic is gone.


When you burn trash, it produces a lot of ash. This ash can float into your home and start a fire. There is also a chance that ashes leaving the chimney could start a fire in the trees or yard. Additionally, like other treated substances, much of your household trash contains harmful chemicals.

Unseasoned Wood

When wood is seasoned properly, it has a low water content. If it is not allowed to dry long enough, on the other hand, it will smoke heavily, invading your living space.

This smoke can make breathing difficult, and it can also leave soot and creosote on your walls and ceiling along with the lining of your chimney. Since creosote is highly combustible, buildups can cause a chimney fire.

Pressure-Treated Wood

According to the Department of Health, CCA pressure-treated wood contains arsenic. When the wood is burned, the arsenic is released via the smoke and ash. Inhalation can lead to deadly consequences for you and your family.

What is Safe to Burn in a Fireplace?

You should only burn approved materials in your fireplace. For the most part, this consists of well-seasoned, untreated wood.

If you are having issues getting a fire going, it can be tempting to toss in some paper or cardboard to get your fire started. In some states this is legal but only for starting the fire. However, there are safe options on the market that will help get your fire going without damaging your chimney or your health.

Fire Starters and Wood Alternatives

The following materials are approved for safely burning in your fireplace and using as firestarters.

Coffee Grounds

Did you know that coffee grounds are flammable? Not only that, but they are also safe to burn in your fireplace. Obviously, you shouldn't dump your wet coffee grounds into the fireplace and try to light them. Instead, empty them out of your coffee pot, and let them dry thoroughly.

In this form, coffee grounds will make an excellent firestarter. However, you can purchase coffee logs that are manufactured specifically for burning in your fireplace or woodburning stove that will last for hours.

Click here to view this coffee log on Amazon.

Wood Bricks

Wood bricks make excellent firestarters. They are typically made with recycled wood chips and wax, making them environmentally friendly and nontoxic.

Click here to view this product on Amazon.

Fire Logs

Fire logs are firewood alternatives. They feature a long burn time and are usually produced with sawdust and grain. They are generally more environmentally friendly than your typical firewood and produce less smoke.

Click here to see this product on Amazon.

Chimney Cleaning Logs

As we mentioned earlier, creosote buildup can cause chimney fires. In addition to regular maintenance, chimney cleaning logs can help clear your fireplace of creosote buildup in between professional inspections.

Build your fire, allowing it to burn for approximately 30 minutes before placing a cleaning log in the fireplace.

Click here to see this log on Amazon.

Choosing Proper Wood

Whether you are cutting your own firewood or purchasing it from someone else, it's important to make sure it is properly seasoned. Most wood needs to season for one year; however, there are some types of wood that dry faster.

When determining if your wood is dry enough, check for peeling bark and a grayish color. Well-seasoned wood will also be easier to split.

Once you purchase your wood or split it yourself, do not leave it lying around. Insead, find a dry place to stack it. Make sure you cover it with a tarp if it is not in a sheltered area. You also should not stack it directly on the ground. Place it at least six inches off the ground.

Should You Burn Boxes in the Fireplace?

You should never burn boxes in the fireplace. Doing so causes toxic fumes to radiate throughout your home, and they can also be released into the community via the chimney.

In fact, fireplaces are tested for safety, and burning anything other than approved wood is not covered by those tests. Therefore, any safety ratings do not include boxes or other waste products.

Is It Illegal to Burn Boxes in the Fireplace?

Burning box

According to the Southwest Clean Air Agency, not only is burning boxes and other waste in your fireplace dangerous, it is also illegal in most states.

This also includes burning waste products outside in fire pits, bon fires, and barrels. Prior to burning any product other than wood, whether indoors or outside, you should contact your state department of health for more information regarding the laws in your area.

In Closing

When you have an excessive stash of cardboard boxes and other paper products, it may seem like a good idea to burn those in your fireplace. Many people believe they are helping the environment by not adding more waste to landfills. However, this is not the case.

If you wish to better the environment, however, the best thing to do is recycle. By burning cardboard and other materials in your fireplace, you are releasing harmful chemicals into the air. This is not only dangerous for you and your family but it is also harmful to the environment.

For more tips on choosing the best wood for your fireplace, check out these other posts:

Can You Put Too Much Wood In A Fireplace?

Can Firewood Be Too Old To Burn?

How Often Should You Add Wood To A Fire In Fireplace?

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