Is Soda Ash Flammable?

In this article, we will discuss the following question: “Is Soda Ash Flammable?”, and other important matters regarding the subject.

Is Soda Ash Flammable?

No, it doesn’t present flammability. It’s an inorganic compound that can’t suffer combustion. An attempt of igniting Soda Ash wouldn’t be successful, and also toxic compounds would not be formed.

What is Soda Ash?

Soda Ash is the same as sodium carbonate. It’s also known as washing soda and soda crystals.

It is not the same as baking soda (sodium bicarbonate).

Sodium Carbonate used to be extracted from plants in sodium-rich soils. The plants are capable of accumulating the compound, so when they were burned, different ashes arose from the combustion.

Sodium carbonate then started being called soda ash.

Soda ash is a form of salt. It is not the same as kitchen salt, it is just another kind.

What is it useful for?

Sodium carbonate has numerous applications.

It can be used as a cleansing agent, or as an ingredient to craft some materials in various industrial processes.

It’s used for the following:

  • Glassmaking. 

It can act as a cleaning agent that lowers the melting point of the glass mixture.

  • Softening hard water. 

Some water supplies may contain certain ions, especially magnesium and calcium, that can be a problem for certain industrial processes and prevent the formation of soap foam in agitated water, which can be a problem in baths.

Sodium Carbonate is capable of reacting and removing chemically those ions, hence softening the water.

  • Cooking.

Since it’s not a toxic substance, is odorless, water-soluble, and slightly alkaline (the opposite of acid), Sodium Carbonate sources can be used to enhance certain properties.

  • It’s a base that can be used to reduce acidity;
  • Can affect the formation of gluten in cookery;
  • Helps enhance Maillard Reactions, which promotes the browning in many foods;
  • It can work as a stabilizer, an acidity regulator, an additive
  • pH regulator.

Can be used to regulate the pH (the acidity) of swimming pools and aquariums.

  • It can be a cheaper source than sodium hydroxide (baking soda).
  • Soda ash can be useful for neutralizing several substances.
  • It’s a constituent of fire extinguishers and toothpaste.
  • Antacid.

Some chemistry of Soda Ash

The primal source of sodium carbonate is minerals. Natron, Trona, and thermonatrite are the most common sources.

When found in plants it’s because it has bioaccumulated on them. 

Like all minerals, sodium carbonate is made available by weathering and/or biological action.

Sodium carbonate (Na2CO3) can also be called Disodium Carbonate. It exists in nature in the form of hydrates (most common) or in its anhydrous form (without water).

Since it’s an inorganic salt, Na2CO3 possesses crystal-like properties. In the hydrated forms, each of its molecules is bonded to water molecules. 

Note that despite having water within, sodium carbonate is solid.

This water is called “water of crystallization”. They are trapped inside crystal structures and affect the distribution of what we call “crystalline framework”.

Crystalline framework example.

Source: adapted from

Note that the structures are very compact. This is resultant of the strong ionic bonds the ions execute.

There are 3 common forms of hydrated sodium carbonates known: monohydrated, heptahydrated, and decahydrated. 

Their names tell the number of water molecules bonded to each sodium carbonate molecule, respectively: 1, 7, and 10. Because of this hydration, each for of salt will have a different structure.

A more accurate to annotate the sodium carbonate structures would be: Na2CO3·XH2O, where we can change the X to one of the numbers mentioned above.

Essentially, a crystal is always made of a small structure that repeats itself (units).

You can imagine it as a pile of Lego pieces. But instead of connecting the pieces only on the top and bottom sides, the units connect to each other on all sides.

The most common industrial source of sodium carbonate is called Solvay Process.

Sodium carbonate is soluble in water, like many salts. Once in the water, it can form carbonic acid (CH2O3) and sodium hydroxide.

Carbonic acid is an unstable molecule that rapidly breaks itself down, forming CO2. This is the effervescence effect that can be seen in some antacids and colas.

Soda Ash Flammability

Soda ash is not considered flammable. It’s also not toxic and explosive.

It is so safe that the U.S. Food and Drug Administration allows it to be used in foods. Other agencies worldwide also do.

Since it’s an inorganic compound, it can suffer from combustion. It won’t ignite and no flames would happen from the attempt of burning it.

But what is combustion?


Combustion is, essentially, a specific type of oxidation.

It requires that a source of fuel is available, with oxygen and heat.

A combustible is something that, once burned, generates a good amount of energy, which we can use.

As a result of the combustion, carbon dioxide (CO2), water(H2O), energy, and heat are formed.  

The problem is: that fuel is an organic compound, normally a hydrocarbon. It’s a chemical that is made of only carbon and hydrogen.

It contains a carbon chain, which acts as a spine. The bigger the spine is, the heavier the molecule. The lighter the molecule is, the more it will look like gas.

The carbons are bonded, and hydrogens are present until each carbon has made 4 connections.


You can imagine oxygen molecules approaching carbon molecules like the ones above. Once they interact hard enough, carbon exchanges the hydrogens for two oxygen, creating carbon dioxide.

The hydrogens also bond with oxygen to form water.

This is how combustion looks chemically.

But where does the heat come from?

You can be wondering why heat happens when something burns, and where it comes from.

Hydrocarbons are used as fuels because they generate a lot of energy once burned. This happens because the chemical bonds between carbon atoms and hydrogen are destroyed.

The energy that once kept the hydrocarbons concise now has been unleashed. Some of this energy comes in the form of heat and the rest is visible light.

Final considerations about the flammability

Soda ash (as Na2CO3·10H2O. for example) also has carbon, but it’s inorganic. It can’t react with oxygen because it already has oxygen, among other reasons.

If you still wish to burn it, all that would happen is that the water would eventually come out of the crystalline network. 

In fact, this is a process called calcination that is used to produce the anhydrous form of sodium carbonate (and is not a form of oxidation).

You can check safety data sheets for Soda ash here, here, and here.

If you require more specific information about this compound, its CAS-N° is 497-19-8

Another important source of chemical information is the National Center of Biotechnology Information. You can check their info here.


Soda ash is another name for sodium carbonate. It’s not the same as baking soda. The compound is not flammable and can’t burn.

Frequently Asked Questions (FAQS): Is Soda Ash Flammable?

What is soda ash used for?

It can be used for numerous ends. To produce many things like glass, detergent, and metals. It can be used as a cleansing substance, as an antacid, in water treatment, and pH regulator.

Is soda ash corrosive?

It can be corrosive to certain kinds of metals and plastics. Since it’s a base, it can react with any acid, which could heat or cold the surroundings. 

Is sodium carbonate a combustible dust?

No. Sodium carbonate alone is not flammable in any form. It is actually used in fire extinguishers. 

Can soda ash explode?

No. Soda ash is not flammable and not explosive. It can’t catch fire and its molecule’s dissociation doesn’t generate a lot of energy (in fact, it might absorb energy).

Is soda ash hazardous? 

Soda ash is non-toxic. It could irritate the lungs if inhaled, as well as the eyes and skin if touched. Individuals with sensitive skin or in a hot and humid place or weather should be advised to use protection.


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