Is Aerosol Flammable? (A Comprehensive Guide)

This article will answer the following question: “Is Aerosol Flammable?”. We will discuss several kinds of aerosols, their nature, and their hazards and also exhibit important specific information on common kinds of aerosols.

Is Aerosol Flammable?

Not every content of an aerosol can is flammable, but most are. It all depends on the ingredients that are used, especially the solvents. Many aerosols use volatile organic compounds like solvents and propellants, creating fire hazards.

What is aerosol?

Aerosol is a state of matter. We commonly name products as aerosols when they can propel aerosols out of a can.

An aerosol is a suspension of fine solid particles or liquid droplets, normally in the air. Essentially, we can say that aerosols are thin solid particles that hover in the air.

We often believe that anything in its powdery form can be flammable, or at least combustible, but it’s not so simple.

Aerosol is not a thing, is a class of things. Is a specific physical state a certain substance can present itself at some point.

For example, we input aerosols into the air every time we sneeze.

Commercially, we name aerosol any kind of canned gas.

Aerosols are used due to the rapid mechanism of action. A can of an aerosol is normally the only tool required to use. After applying it, its solvents will fly away, and then the job is done. But this easiness often comes with a price: flammability.

Aerosol properties

Aerosols can be made of many things. For example, organic molecules, sulfates, nitrates, mineral dust, and sea salt are things that can become airborne in the form of an aerosol.

Aerosols (now, under-pressure canned substances) action happens by applying the product to a certain surface. 

Some of the ingredients will remain on the surface, others will evaporate in the air. Others don’t do much besides carrying other relevant compounds into the surface. 

But all of them are equally important and are inside the can for a reason.

Aerosol products formulas are created considering 4 basic components: 

  • Active ingredient(s), are the things that have active participation in the labor that’s being done;
  • Solvents, which are substances in bigger quantities, are often required to mix the active ingredient, or dissolve something else in the region that’s being applied;
  • Propellants are gases used to carry the other ingredients out of the can. Normally, they will dissipate right after squeezing the can’s button.
  • Binders. These molecules play secondary roles, acting like binding agents that make the other ingredients mix while inside the can.

All these ingredients combined can formulate the mist, dust, fume, smoke, or fog that comes out of the can. Some compounds used in aerosols may possess more than one functionality.

Aerosol hazards

Since the nature of aerosols is to become airborne, the products have specific hazards associated with them.

Health hazards

Overall, the biggest threat to our health is in our respiratory system, since the particles can be inhaled. Several problems may arise from breathing an aerosol, and it’s not rare that it leads to death.

Although, such a thing won’t happen unless you pierce it directly into someone or yourself, inhaling or ingesting. Spray disperses quickly so they’re not hazardous if used according to instructions on the label.

Active ingredients in aerosol adhesives, insecticides, automotive sprays, solvents, cleaners, paints, and varnishes, for example, are often hazardous to our health and the environment.

Flammability hazards

The flammability hazard is also high if the ingredients or an aerosol are combustible. Volatile compounds are in the most burnable state possible, especially if they are under pressure inside a can.

While in gas or aerosol form, combustible compounds are dispersed in the highest surface area possible, meaning that a combustion reaction would take place as fast as possible, if it has the right ingredients to do so.

Aerosol cans will have their inside pressure increased if heated. If heat itself was not enough fire hazard, the can may also leak and explode because of that, especially in workplace environments.

Cans also shouldn’t be pierced, shaken too much, or impacted, and may also be stored safely.

NFPA 704

Many government and non-governmental organizations establish systems, codes, and categories to express the overall hazards substances have.

The NFPA 704 is a standard maintained by the National Fire Protection Association, based in the U.S.

Also known as Safe Square and Fire Diamond, it uses a diamond with four divisions and colors. Each is rated on a scale of 0 to 4, known as Degrees of Hazard.

The four divisions have one color each. The red on the top indicates flammability, the blue on the left indicates the level of health hazard, and the yellow on the right is for chemical reactivity. The white at the bottom contains codes for special hazards. 



There are also exist simpler kinds of hazard pictograms. Below we present some of them. Their purpose is simply to expose generally the kinds of hazards a certain substance can present.


OSHA (the United States Department of Labor) classifies flammable aerosols in two categories:

  • Category 1: Extremely flammable substances.
    Substances that contain over 85% flammable components, and that the heat of combustion is bigger or equal to 30kJ/g. Spray and foam aerosols are included. There are also other properties like flame duration and height.
  • Category 2: Flammable substances.
    Substances that contain around 1% or more of flammable components, or that the heat of combustion is bigger or equal to 20kJ/g. It’s valid for spray and foam aerosols as well, each having its criteria


Aerosol products are often associated with high and extreme flammability and explosions.

How flammable a certain content of an aerosol can will depend on its ingredients. Although, the ingredients alone can only satisfy part of the answer because substances can behave differently according to the mixture.

Also, the specific composition of most aerosol products is a trade secret. The companies usually present a range of values for each ingredient at best.

Nevertheless, by knowing which solvent is used in each formulation we can assume rather an aerosol substance can catch fire or not.

But there’s another and more reliable way to understand if an aerosol product is flammable or not: its Safety Data Sheet (SDS). This is a document that compiles all relevant information regarding the safety of a product, under a set of conditions. 

The easiest way to find SDS is to simply google the product’s name followed by the words “safety data sheet”, or simply “SDS”. If you feel that there’s too much information on it, try localizing the word “flammable” or “flammability” in the document.

But of course, we will always be here to assist you.

The same compound can have different safety information bound to it, depending on if it’s meant to be used domestically or industrially, for example.

Safety data sheets

You can check further information about specific labels in the links below. Category one, according to OSHA, means that’s an extremely flammable aerosol. Category two means that’s only flammable.

WD-40 Multi-Use Product Aerosol: Category 1

WD-40 Aerosol: Category 1

BYCOTEST® RP20 – aerosol: Category 1

Spray unit: category 1

Dove Antiperspirant Deodorant Original: not flammable.

Aerosol ALL Purpose Spray Paint: Category 1

3M™ Super 77™ Multipurpose Adhesive (Aerosol): category 1

Gorilla Cleaner Safety Solvent (aerosol): It’s combustible, but presents no fire hazard.


No matter what kind of aerosol you’re using. It could be a deodorant, paint, remover, adhesive, perfume, insecticide, degreaser, lacquer, or any kind of under-pressure gas that’s released through the squeeze of a button.

All aerosol products must be kept away from any source of heat, sunlight, sparks, and flames. Both the cans and contents.

Also, aerosol cans must be stored properly. The button and valve should remain clean and unobstructed, and the can shouldn’t go through any kind of stress. Leaking prevention is really important.

After an aerosol dries, it’s not likely that a remaining stain will remain flammable. The active agents in any kind of aerosol are just a few particles that probably can’t ignite easily. 

If they eventually do ignite, they’re not likely to become a fire hazard because the scenario required to do so would already have been hazardous.

Direct flames are required to burn a stain. These flames would probably be more hazardous than the fire generated by the combustion of fewer materials dried from the aerosol.

The reader is probably tired of reading this but, we must say that aerosols must be kept away from children and pets. Inhalation of aerosol mists, even by something harmless as a deodorant, can result in death, besides being normally highly flammable.


The content in aerosol cans can be flammable, but it depends on the ingredients. An aerosol can be considered flammable even if only a few of its ingredients are flammable. To correctly assess flammability information is better to read safety data sheets.

Frequently Asked Questions (FAQS): Is Aerosol Flammable?

Is aerosol bad for the environment?

The content of aerosol cans may be considered bad for the environment, but that’s only part of the story.

The gases, liquids, or aerosols that are inside an aerosol can are probably greenhouse gases, but the quantity is too little. 

The biggest threat of aerosols is the harmful content of the active ingredients, overall, and the incorrect discard of the cans.

On a global scale, industries emit only 21% of the total greenhouse gases. Agriculture, electricity, and heat production combined compose about half of the global emissions.

Is aerosol deodorant flammable?

Not all of them are, but it’s safer to assume an aerosol deodorant is flammable unless you check for safety data specific for the exact label you’re in doubt.

Most aerosol deodorants use alcohol in their formulation. Alcohol helps to carry the deodorant active ingredients into our skin, but then it flies off through evaporation.

Are aerosol cans recyclable?

Yes, they are. Commonly they are made of metals such as aluminum and steel, which are highly recyclable.


What was missing from this post which could have made it better?

Leave a Comment