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CHARCOAL: How Does It Really Work?

Though Charcoal is by no means our only detoxifying and deodorizing ingredient, it is certainly the most visible, and one SOOTSOAP was built around. It also gets a lot of attention! Why? Because Charcoal - or Carbon - is the most adsorbent natural material known to man and is one of the reasons SOOTSOAP works so incredibly well.

Activated Charcoal has been used for thousands of years for detoxification, deodorization and filtering. It is used in cases of poison ingestion, water filtration, toxic cleanup - even gas masks. When harnessed correctly, Charcoal is an incredible ally for personal decontamination and detoxification.

SOOTSOAP is saturated with the purest Charcoal and other all natural powerhouses to adsorb toxins and odours, naturally.


But how does Charcoal ACTUALLY work? 

To understand how it works, we need to look at:



Activated charcoal (or activated carbon) involves cooking a carbon-rich material at high temperatures to chemically change its structure in order to enlarge its surface area, maximize the number of pores and, ultimately, increase its adsorption properties.

You can make activated charcoal out of pretty much any organic material that burns, including bamboo, coconut, wood, peat … even corn husks or coffee shells. The most typical type of activated charcoal is 'black’ charcoal (usually just referred to as “charcoal”), which is an organic material cooked at 400 to 700 degrees in an oxygen-void environment and left to naturally cool.⁠ The cooking process removes solid mass, replacing it with an intricate network of pores. Depending on the source material, cooking process and cooling process, charcoal as an ingredient is incredibly varied in structure and quality.

“White Charcoal” is made with hard wood such as oak or eucalyptus, burned at a lower temperature of 200 to 400 degrees for a long time before the door is opened to let oxygen in and then the heat is turned way up to a staggering 1000 to 1200 degrees. After an intense burn, it is cooled very quickly with a covering of ash, giving it the name "White Charcoal" (White Charcoal itself is indeed still black, it’s the ash covering that gives it the name “white”). Cooking hard wood at an intense temperature creates a much harder and larger surface area, has lower sulphur content and has much higher Carbon content, or purity.


Binchotan Charcoal is a type of White Charcoal that has been traditionally made for thousands of years in the Kishu province of Wakayama in Japan, using branches from the extra hard Ubame Oak tree. The Binchotan artists in Wakayama have perfected a sustainable technique that produces charcoal of extraordinary purity

Traditionally, Ubame branch clippings were stacked inside mountainside kilns and burned at low temperatures over several weeks to control the flow of oxygen. The temperature was then raised to over 1000 degrees. Once the smoke was clear, they knew all of the impurities had been burned away and the Charcoal was ready. They then cooled it quickly by a covering of white ash. Because of its much refined, very specific ingredient and specialized process, Binchotan Charcoal is known as the hardest, purest form of Charcoal, and continues to be made in this tradition today.


The structure of Charcoal is key to how it works. All Charcoal - regardless of the source or process - is made up of macro, meso AND micro pores, which rely on each other for adsorption to take place. Macro pores make up the outer surface and micro pores on the inner surface, with the meso (or trans) pores, connecting them.

Generally, micro pores will make up at least 90% of the total surface area of Activated Charcoal, which is important because most of the adsorption takes place in these small pores. BUT, macro and meso pores are just as important, as they serve as the transportation to the micro pores, much like the trunk of a tree root system.

Illustration of a tree with a complex root system. Like the root system of a tree, the structure  of Charcoal is key to how it works. Regardless of the source or process, all Charcoal is made up of macro, meso AND micro pores, which rely on each other for adsorption to take place. Large macro pores collect particles from the surface, transport them through the meso pores (the large reaching roots), and into the smaller micro pores (all the tiny little roots), where they are bonded.

ADSORPTION is where a gas, liquid or dissolved solid substance chemically adheres - bonds - to the surface of another particle. If you think of absorption like a sponge, where a bulk liquid  is brought inside in a bulk fashion, adsorption would be if individual atoms, molecules, or ions were pulled from that water solution, gathered onto the surface and bonded permanently, without ever needing to be 'sucked' in as a whole.

First round sphere shows three molecules "attached" on the outer surface, with the description "adsorption" underneath. Second round sphere shows three molecules inside, with the descriptor "absorption". Accompanying text reads "ADSORPTION is a surface phenomenon, where a gas, liquid or dissolved solid substance chemically adheres - bonds - to the surface of another particle.  ABSORPTION is where a bulk substance (and all of its ingredients) are fully brought into another substance - soaked up as a sponge"


So what makes a ‘good’ charcoal? First, it’s important to understand that we cannot generalize all types - or all Charcoal from a particular source - into a statement of fact, as there is so much variation that goes into making and using it. In order for such a generalization to be accurate, we would have to test literally every Charcoal with every toxin, and those hypotheses would have to be peer reviewed by other scientists. Given the sheer number of sources, processes, final Charcoal ingredients out there, and number of toxins, this is a physical impossibility, and a waste of time. We therefore couldn’t say “all bamboo charcoal does X”, or “coconut charcoal isn’t good at…”, as each and every charcoal will have a different structure and capacity for adsorption depending on how it's made and used.

So, instead, let’s ask WHAT DETERMINES THE ADSORPTION CAPACITY OF A PARTICULAR CHARCOAL INGREDIENT? Here are a few of the determining factors:

1. The Source Ingredient. 
    • Quality of Starting Material - The material that you start with has a lot to do with its capacity for pore maximization and therefore adsorption - the quality of the material itself, its structure and its density and hardness are all important factors.  Ultimately, the lower in inorganic matter (inorganic materials are non porous), and the more dense / hard, the better the potential for an adsorbent Charcoal 
    • ‘Cooking’ Process - The purpose of the cook is to maximize surface area and pore structure. Much like any specialty, it’s a skill to be mastered and there are varying levels of quality based on this process - different cooks result in different structures, even from the same source ingredient
    • How it is used - Just like any ingredient in any recipe, the final adsorbency of Activated Charcoal relies heavily on the experienced hands of the maker - the farmer, retailer and, ultimately, the chef

2. Surface Area. Because of how carbon works by affixing to adsorbates (the thing being adsorbed), a relatively large specific surface area is one of the most important properties that characterize carbon adsorbents (the thing doing the adsorbing). Studies have found that increasing the higher final temperature increases the hardness of the resulting Charcoal, giving it a larger surface area. This of course does mean potentially burning away more mass, making it more costly.

3. Carbon Percentage. The higher the temperature, the more biomass, or volatile / inorganic material, is cooked off, resulting in a higher percentage of carbon. Activated Charcoal can be made up of anywhere from 50% to 95% carbon depending on the ingredient and how it’s prepared. The goal is generally to get as close to 100% carbon as possible in order to maximize adsorption potential and minimize inorganic content.

4. Microstructure. While a very porous microstructure is critical, as this is where the actual adsorption takes place, a well developed meso and macroporosity (those transporting and accepting surface pores) is also necessary for the passageway to adsorption of solutes (toxins) from solutions. A high performing adsorbent will have good pore size distribution - a high density of macro pores, solidly performing meso pore structure and a large area of micropores.

5. Pore Distribution. Not all organic molecules can be adsorbed by all Charcoal. In order for a molecule to be adsorbed, it must ‘fit’ within the pores presented by the Charcoal. In other words, the Charcoal micropores must have a diameter larger than the pore width of the molecule to be adsorbed. Now, we’re only concerned with toxins here - PAHs, VOCs, PFAS, environmental pollutants...etc. The size range for these toxins is between 0.5 and 10 nanometers. So our charcoal micropores must present within these diameter parameters. 

Chart showing size comparisons of particles in nanometers. Size range for toxins fall within 0.5 to 10 nanometers. The scale goes larger with virus cells, bacteria, cancer cells, all the way up to a baseball. A nanometer (nm) is one thousand millionth of a meter, meaning you need  an electron microscope to see it. Accompanying text reads: In order for a contaminate to be adsorbed, it must ‘fit’ within the pores presented by the Charcoal. In other words, the Charcoal micropores must have a diameter larger than the pore width of the substance to be adsorbed.  The size range for our target toxins is generally between 0.5 and 10 nanometers *  Your average charcoal's micropores are < 2 nm diameter.  Binchotan Charcoal has a very porous microstructure with micropores <10 nm diameter.

6. Other Sciency things … There are other factors that are important as well, including hydrophobic (water avoiding) surface presented, polarity, chemical activation, etc.  We're happy to nerd out more on these if you’re interested ;)



SOOTSOAP detoxifying and deodorizing products use specifically, and exclusively, Binchotan White Charcoal in addition to our other powerful detoxifying and deodorizing ingredients as an important part of the decontamination process.

This choice was made with a great deal of research over the course of several years, and remains a very deliberate one. Why?

  • Binchotan as an ingredient is incredibly reliable. It is made in a small region, with a specific, controlled and regulated process, by highly specialized ‘cooks’. We can rely on a consistently high quality product and result given less variation.
  • Binchotan is cooked at much higher temperatures, which increases the hardness and surface area of the final material, thereby increasing adsorption capacity. Where a black Charcoal will turn to dust in your hands, Binchotan will sound like wind chimes. It can even be carved!
  • Binchotan is made with sustainability as a priority.
  • Because of its source ingredient and process, Binchotan is about as close to pure carbon as you can get (95%+)
  • Binchotan has a very porous microstructure (<10 nm in diameter), with a high density of macropores (~100 nm)
    • Remember - size range for our target toxins is between 0.5 > 10 nm, and a well developed meso and macroporosity is necessary for the adsorption of solutes from solutions, making Binchotan structure ideal for our target toxin adsorption



Does Charcoal remove dye?

It can … though strangely, Charcoal is better at removing red food dye than yellow, and even worse at removing blue (it has to do with polarity). But in all honestly, we don’t care. We’re not concerned with colour adsorption any more than we are butter, because it's not evidence of toxin extraction, which is where our focus lies.

Adsorption is due to the hydrophobic (water avoiding) surface presented by the carbon surface of charcoal. That means charcoal is great at removing other water avoiding substances (like toxins) from a solution. Dye is hydrophilic, meaning it dissolves in water - the more hydrophilic a substance is, the less the chance it will be adsorbed. Further, food dye is an inorganic substance, there are pretty simple ways to clean it up with items from your kitchen and, most importantly, it's not a toxin and doesn't act like one. It's about as irrelevant as it gets.

Conversely, PAHs and VOCs are hydrophobic, non-polar toxins, making them ideal for Charcoal extraction.

Plus, when was the last time you had a fire at a food dye factory? If you do, we hope it wasn’t blue… 


Does it help to have more than one kind of Charcoal?

I guess it would depend on the specific ingredients, the formula and the cook. As a rule, no. As we know, we can’t categorize Charcoal based on the source ingredient alone, as there are so many other variables that go into its capacity for adsorption - Charcoal ingredients made from the same source can vary wildly in microstructure.

We have found that using the most reliable Charcoal with the largest surface area and the highest capacity for the adsorption of our targeted toxins does the trick, especially when combined with all of our other powerhouse detoxifying and deodorizing ingredients and put in the incomparably experienced hands of our lab. You only need one when it works.


Who was SOOTSOAP originally created for back in 2018?

Firefighters! Dee co-founded SOOTSOAP after several years of research and development in an effort to keep her husband - a firefighter - clean. She originally was looking to develop a product to combat that notoriously impossible-to-get-rid-of smell of smoke all too present with firefighters, and in doing so discovered the terrifying source.

SOOTSOAP was developed to remove as many toxins as possible from the skin and hair in an effort to keep her husband and our firefamily community healthier and safer… It also gets rid of ‘that’ smell - and so many others - in just one wash! Firefighter safety remains at the heart of what we do today, with a portion of our proceeds going back to firefighter charities in communities where we’re sold.


Do you get rid of more toxins than anything else?

We won’t make this claim until the day we can definitively, scientifically, prove it, and no one else should either. Our mission is a critical one, and we won’t ever make wild, unsubstantiated claims for the sake of selling bottles. Please be cautious of those who do. Further, we follow Health Canada and FDA regulations, which rightfully don't allow such unproven claims.

We are, however, not only the first liquid soap with activated charcoal developed specifically for firefighters, we are also the best all-natural product targeting personal decontamination on the market today, and will continue to work so that remains true. We encourage you to test us against any other product and rely heavily on your feedback, as we always have.


Why is sustainability important?

To create Charcoal, a significant loss of mass has to take place - a lot of the source material is literally burned away by design, leaving maybe only 5% - 10% to become our end Charcoal. It is our duty as citizens of the world to ensure we are sourcing sustainable ingredients. Binchotan is made with sustainability in mind, as is SOOTSOAP.


We hope you found this informative! We nerd out on our ingredients a bit more than most and are always fully transparent. Please reach out if you have any additional questions!



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