Eco-Tips: How To Dispose Of Charcoal Ashes Harmlessly?

To dispose of charcoal ashes harmlessly, ensure they are completely cooled before mixing them with water to create a natural, eco-friendly detergent for cleaning.

Charcoal is generally used for the combustion process, both in making dishes and heating rural houses in winter. People also commonly use them to throw barbecue parties. But here’s the problem! Not many understand how to dispose of charcoal ashes after grilling safely without harming our earth. Of course, this is a serious issue since charcoal disposal can pollute the groundwater and soil, especially coal ashes.

And for that reason, we are here to broaden your insight to find a safe way to dispose of ashes. We will also talk further about the environmental problems caused by charcoal briquettes. Thus, we can be more aware of disposing of coal ash. Without any further ado, let’s dive in!

Key Takeaways
  • Cool down charcoal ashes completely before disposal to prevent accidents and enable safe recycling.
  • Use cooled ashes as a natural fertilizer in gardens to enrich soil with essential minerals.
  • Mix ashes with water to create an eco-friendly detergent for cleaning clothes.
  • Charcoal ashes can be recycled for various uses, including as a metal cleaner or for melting ice.
  • Proper disposal and recycling of charcoal ashes minimize environmental pollution and contribute to soil health.

Charcoal Ashes

Before we are heading to our main topic of how to dispose of charcoal ashes harmlessly, it would be better to understand what charcoal actually is. It is also crucial to know how many types of charcoal, its benefits, and how to reuse charcoal properly. Find the details in the following sections.

1. What Are Charcoal Made Of?

Basically, charcoal is a solid black, porous, odorless material that is generally made from coconut shells, wood, bones, peat, or cellulose. The manufacturing process (pyrolysis) is carried out by burning those biomasses in the absence of oxygen. It is crucial to avoid combustion as oxygen quickly catches flame. Also, the water and other volatile compounds are removed.

What Are Charcoal Made Of
What Are Charcoal Made Of

The temperature used is roughly around 750°F or 400°C. On the contrary, charcoal contains carbon which makes it easier for the combustion process. When oxygen and carbon combine, they form Carbon Monoxide (CO) and Carbon Dioxide (CO2).

These compounds are toxic if inhaled in 10-30% concentrations, leading to respiratory issues such as shortness of breath and asthma. Even worse, coma and death.

2. Harmful Chemical In Charcoal

Charcoal is commonly used in various purposes, such as heating the house, roasting foods, alternative fuel, and painting ingredients. However, this material has chemicals that are considered harmful for our health. What are those?

Carbon Monoxide (CO)

The most dominant and harmful chemicals that are most wary of charcoal are Carbon Monoxide (CO). Even though it is not directly contained in it, carbon monoxide is formed from the meeting of carbon and oxygen present during the combustion.

What makes it dangerous is that CO is odorless, so it cannot be detected by smell. Not a few news mentions that carbon monoxide causes poisoning due to inhalation of too much. One of them is the case in Hanoi, Vietnam. It was reported that women using coal-based charcoal briquettes for cooking experienced dizziness and loss of concentration due to using this material.

Furthermore, according to data, the generation rate of CO during the combustion process is in the range of 137-185m/min/kW. If you inhale this toxic gas of 30-70%, you will end up in the emergency room due to collapse. In the worst case, CO can cause death.

Harmful Chemical In Charcoal
Harmful Chemical In Charcoal
Sodium Nitrate 

One of the ingredients for making charcoal briquettes is sodium nitrate because the price is affordable and accessible. It acts as a strong oxidizer that makes your charcoal easy to light. Due to this role, this chemical is harmful to human health. High exposure to sodium nitrate may limit oxygen absorption to your blood system and cause hypotension.

The poisoning characteristics of this hazardous chemical are nausea, vomiting, diarrhea, and loss of consciousness. If it’s severe, the symptoms will accelerate to hypoxia and cyanosis. The maximum exposure of sodium nitrate is 10 mg/L. Knowing this danger, it is important to find a safe disposal for your briquette ash. Or, reuse charcoal.


With sodium nitrate, borax is one of the chemicals used for charcoal briquettes. It can bind the briquette and will make the charcoal fire burn brighter. Unfortunately, this chemical can be dangerous to health. Some of the symptoms that may appear when poisoned are nausea, vomiting, abdominal pain, diarrhea, and skin rash.

In addition, the inhaled toxicity range is about ≤ 0.05 mg/L.

3. Benefits Of Charcoal Ashes

While charcoal is useful for heating and cooking, the ashes obtained from charcoal after grilling apparently also have many benefits that are no less important. Especially those made of biomass, such as wood, peat, bamboo, cellulose, and bones.

Curious about the advantages of charcoal ashes? Find out below!

Natural Fertilizer

Turning charcoal wood ashes into natural fertilizer can be an effective way to dispose of ashes. It is common knowledge that ash is rich in iron, zinc, copper, potassium, and phosphorus. The percentage of each of these minerals depends on the tree type, temperature, and burning time.

how to dispose of charcoal ashes
Charcoal as Natural Fertilizer

Hardwood charcoal generally has higher potassium and phosphorus content. However, the calcium is lower than the soft wood. These minerals are beneficial in stimulating new roots, fruits, flowers, and seeds.

Besides, charcoal ashes also contain useful cations to neutralize or increase pH levels. Though it helps the acidic soil to be more suitable for most plants, too much is never recommended. Alkaline soils can slow down their growth. So, moderation is always the key. You can apply wood ash to tomatoes, leeks, greens, or squash.

Repel Pests

Chemical pesticides or insecticides may be effective in quickly keeping the pests away. However, their long-term use is detrimental to our environment. They reduce soil quality, thus reducing the useful life of the land. Luckily, you have a wide choice of natural pesticides to deter pests now, one of which is using charcoal wood ashes with neem oil.

Repel Pests benefits
Charcoal as Repel Pests

A study reported that a mixture of the two can reduce insect infestations, such as sitophilus zeamais. This may be due to potash in wood ashes and azadirachtin, which act as a natural pest repellent.

Reduce Corrosion

Coal charcoal ashes disposed of in landfills can harm mother earth. It is due to its toxic chemicals, such as mercury, arsenic, and cadmium, which will pollute groundwater. Instead of disposing of coal ash, you can use it to prevent corrosion on concrete.

A study stated that making concrete with the addition of fly ash, the fine residue of coal ash, can decrease cracking, improve durability, and reduce permeability. It is possible due to a pozzolanic reaction that converts calcium hydroxide to calcium silicate, ensuring all those mentioned benefits.

4. Are Charcoal Ashes Recyclable?

Considering those benefits, you can recycle charcoal ashes made of natural biomasses. In fact, this may be the best way to safely dispose of charcoal cold ashes. You can try to use them to polish your jewelry by mixing ashes with baking soda. Then, add water to make a paste-like texture. After that, dip a sponge and rub it on your silver or gold.

Briquettes as Natural Biomasses
Charcoal Briquettes as Natural Biomasses

Moreover, some people use it as a natural detergent to wash their clothes. If you wanna try it, make sure to finely sieve the ashes. Next, add them into a bucket, then add filtered water. Then, mix it well and put your clothes in it. Another good news is you can use the wood charcoal ashes to melt down ice since they contain salt.

Simply sprinkle the cold ashes onto your plastic-wrapped ice and watch it melt away.

How Long Does Charcoal Ashes Take To Decompose?

One of the concerns for finding a way to safely dispose of charcoal briquette ash is the decomposition period. According to one study, charcoal ashes can be buried in the soil for thousands of years (approx. 8000 YEARS). The decomposition process takes much longer than plastic materials that last around 1000 years.

In addition, the buildup of charcoal on this soil has a negative impact on the environment. Still on the same study, mentioning that this phenomenon will lead to a reduction of soil mass.

how to dispose of charcoal ashes
How Long Does Charcoal Ashes Take To Decompose

Consequently, wood ashes deposited due to wildfires can potentially lower the soil’s carbon content due to mass loss. It is sad news since carbon is the most crucial part of life on earth, where most of its content is in soil and rocks. Can you imagine if we use our soil as a recycling bin to dump coal and ash carelessly?

Charcoal Ashes Environmental Problems

Charcoal made from wood, bamboo, peat, and cellulose are less harmful because they are natural ingredients. They even share benefits for soils and plants, such as boosting soil microbial populations and encouraging plant growth by providing essential minerals. 

Unfortunately, that’s different from coal-based charcoal.

This material is highly concerning due to its mercury, cadmium and arsenic, and heavy metal contents. Their concentration is rather high because of the combustion process that removes almost all elements, such as oxygen, carbon, nitrogen, and hydrogen. Hence, the lack of safe disposal management is detrimental to our ecosystem since those metals will pollute soil, water and air.

Charcoal Ashes Environmental Problems
Charcoal Ashes Environmental Problems

Furthermore, data stated that carbon dioxide air pollution caused by burning coal charcoal in the U.S. is up to 20% of total energy-related CO2. Also, coal combustion in the country produces around 100 MILLION TONS of coal ash annually. What a shocking number! If this continues, we are only waiting for the catastrophic effect as a result of this pollution.

Other than the air pollution, the soil that often becomes a charcoal disposal bin also suffers from the ashes. As we previously discussed, the ash accumulation can cause carbon loss in the soil, threatening the ecosystem we live in.

The Right Ways On How To Dispose Charcoal Ashes

At this point, we assume you have known the benefits and environmental effects of charcoal ashes. It is important to look for a safe way to dispose of the ashes so that they won’t pollute our earth. Here are methods on how to dispose of charcoal ashes and recycle them harmlessly for environment:

1. Cool It Down

If you buy disposable charcoal for BBQ parties, you must let them cool down for at least 48 hours. Let them sit on your fire pit or scoop them into the aluminum foil that can protect your hands from burning, in case they are still hot. This way, you can reuse the ashes again.

After that, throw them to the non-combustible charcoal disposal bin. In case you are in a rush, pour water to decrease the temperature. However, you cannot use the ashes again for the next grill.

2. Make Natural Fertilizer

This is the most popular safe way of disposing wood ashes. The ashes are safe to add to your compost bin and in fact give more minerals to it. But make sure not to give too much as it will interfere with the fermentation process.

The Right Ways On How To Dispose Charcoal Ashes
The Right Ways On How To Dispose Charcoal Ashes

Besides making compost, you can also sieve the ashes and pour it directly on the topsoil to encourage your plants growth. Unfortunately, this method cannot be applied to dump coal and ash due to their toxic chemical contents.

3. Metal Cleaner

It has been known for a long time that charcoal works best as a natural absorbent of dirt. And even cooler, they can clean and polish metals too! You will need two cups of finely sieved charcoal ashes and four tablespoons of baking soda. Then, mix them with water to create a thick texture paste. Use a sponge, take the paste and clean the silver or gold you want.

4. Natural Detergent

Recycling ashes is the best way to dispose of these materials. It is harmless for the environment and saves you some money! One way is to make natural detergent out of the ashes. You can mix the powdery ashes and mix it with hot filtered water in a barrel.

The ratio is around 1:4 for the ashes and water. Now, stir them and let it for a while until the particles settle at the bottom. And voila! Use around one cup to clean your stained clothes.

How To Dispose Charcoal Ashes At Home?

Since the use of charcoal is generally on a household scale, it would be nice to know how to dispose of charcoal ashes safely at home. The method is very easy, but you have to be careful because the average combustion temperature of charcoal is 400°C – 500°C. Follow the step-by-step guide below!

  • Let it cool down. It is important since the hot temperatures can easily burn your hand when you touch it. Settle it for at least 48 hours in your fire pit.
  • Gently scoop it out from the pit with a small metal shovel to a container. Brush the hole to remove the excess ashes.
  • Transfer the ashes from the container to aluminum foil. This material will cool off the ashes to prevent burning your hands and other materials in the recycling bin.
  • Wrap the aluminum foil tightly. But make sure they are kept intact.
  • Now, dump it in the charcoal ashes bin. We recommend not mixing the ashes with other materials to prevent combustion because of high temperatures.

Charcoal Environmentally Friendly Alternatives

Are you someone who is concerned about the environmental impacts of charcoal? You have arrived at the right place! We have compiled several alternative products to charcoal that will have little to no negative effects on our mother earth. Hence, you can have fun barbecuing or warming your house without feeling guilty. Check out below!

1. Pellet Wood Grill

You can rely on pellet woods for grilling your BBQ meats to replace the charcoal. They are an environmentally friendly option that will burn quickly and leave no ashes. So, you won’t be bothered to look for how to dispose of charcoal ashes anymore!

Pellet Wood Grill
Pellet Wood Grill

With no ashes produced after burning, you reduce the potential soil pollutant that has detrimental impacts. In addition, wood materials are sustainable, unlike fossil-based fuels like charcoal.

2. Sawdust Wood Briquettes

While coal briquettes are harmful for the environment, the sawdust briquette is the best bet as an alternative to these products that won’t give detrimental impacts for the earth. Similar to the firelogs, it is made of birch or alder used wood.

Sawdust Wood Briquettes
Sawdust Wood Briquettes

These hardwoods are considered the most ideal ones to make fire. By purchasing the briquettes, you can also reduce the emissions, thanks to the recycled materials.

3. Light Firelogs

Firelogs are products made from dry wood fiber waste which will likely be sent to a landfill. These materials will be compressed into various shapes and sizes before being packed. Hence, you can find the best ones that fit your fire pit.

Light Firelogs
Light Firelogs

Considering the recycled materials, using light fire logs means you also contribute to cutting carbon emissions since no other trees are cut. The price of this eco-friendly product is also quite affordable. Thus, you have no excuse to replace your charcoal with these eco logs.

Final Thought

Disposing of charcoal ashes is tricky if you don’t know how to handle them. Aside from the hot temperatures, the ashes are also potentially harmful to the environment. Instead of dumping the ashes into the recycling bin, which will end up in the landfill, our experts highly recommend recycling them.

The easiest way is to sieve the ashes, then spread them to your crops. They are rich in minerals that will boost their growth. Besides, you can use them to clean your clothes, even your jewelry. This way, you contribute to saving the environment by minimizing pollution.

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FAQ (Frequently Asked Questions)

Is charcoal ash recyclable?

Even though the ashes from charcoal grilling seem useless, you can recycle it. In fact, recycling ashes is relatively easy. Some people use the ashes to polish their valuable sterling silver to make it shinier. They are also a great material for making cleaning soap for unclogging drains. As for agriculture, you can reuse charcoal ash to make compost.

Are charcoal ashes biodegradable?

If your charcoal ashes are made from wood and lumps, you can safely add them to your compost bin. However, that’s not the case with charcoal briquette ashes. They are made with additional chemicals that are potentially harmful to the environment. So, these charcoal briquette ashes will most likely end up in landfill.

In addition, burning charcoal produces carbon monoxide (CO). This toxic chemical can cause respiratory problems, skin rashes, and even death if you inhale too much CO.

Can you put charcoal ash in a compost bin?

You can add charcoal ash to a compost bin as long as it is made of wood or a lump. The ashes will increase the pH of your compost and the carbon content in your compost. Carbon is one of the elements stimulating the production of proteins and carbohydrates in plants.

But don’t give charcoal ash too much since it can make your compost too alkaline. Thus, slowing down the composting process in the bin.

Is charcoal ash good for the garden?

In case you have ashes of lump or wood charcoal after grilling, you can spread them to your garden plants. The ashes from the charcoal grill are loaded with potassium carbonate, which improves water absorption of the soil. Hence, keeping it moist.

Besides, the chemical also keeps the stems and roots robust. In addition, the used charcoal ash can increase soil pH. However, it is not recommended to give too much as it will slow down your plants growth.