Is Formaldehyde Flammable? − All You Need To Know!

Surely, we have all handled the industrial disinfectant formalin and its mother form, formaldehyde. This naturally occurring pungent-smelling organic compound is colorless and greatly contributes to paper, resin, and fertilizer production.

But with its wide usage in different sectors, do you wonder, ‘Is formaldehyde flammable?’

Yes, formaldehyde, the colorless gas, is flammable at room temperature. With its low flash points and high reactivity tendency, the flammability risks of the substance take a peak.

However, that’s not the whole story; there’s a lot more to it. If you’re up for learning more about the flammability of formaldehyde, precautions, and to-dos in case of an unfortunate event, stay with us!

A few minutes here might save you from fatal situations!

What Happens When You Put Salt on Fire Besides Formaldehyde Production?

The salt burning experiment results in more than just the production of formaldehyde. When salt is placed on a fire, it emits a yellow color and creates a bright flame for a short period. The salt also acts as a catalyst, introducing new chemical reactions that can change the color of the flame and even create new compounds. However, this effect is short-lived and shouldn’t be relied on as a method for extinguishing fires.

Why Is Formaldehyde Flammable?

No doubt that formaldehyde is flammable, but why so? If you’re wondering, it’s because of its chemical properties and reactivity with other substances.

More details as you scroll through!

Why Is Formaldehyde Flammable

Increased Reactivity

Due to its strong and fast reactive property, formaldehyde easily creates heat, light, and energy when it reacts with several compounds, including oxygen. With the right conditions, it can even result in the emergence of fire.

Lower Flash Point

The temperature at which a specific substance releases vapor to ignite in the presence of any fire source is known as the flash point of that very substance.

Now, when it comes to formaldehyde, the flash point is very low, only 50 degrees C for a 37% formaldehyde solution. This implies the solution can catch fire if exposed to an open flame, heat, or spark.

Acts as a Reducing Agent

As you know, formaldehyde is a strong reducing agent, and it frequently lends electrons to other compounds for bonding.

This can be proven dangerous, as formaldehyde can start a fire when in contact with oxidizing substances like bromine, oxygen, fluorine, chlorine, hydrogen peroxide, etc.

High Heat of Combustion

With a high heat of combustion or standard enthalpy of combustion of 541kJ, formaldehyde is easily identified as a substance with a relatively high heat of combustion. 

The high heat of combustion means more heat and energy production during combustion, resulting in a flame!

Explosive Mixtures Formation With High Vapor Pressure

When the concentration level of formaldehyde ranges between 12.5 to 70%, it can easily combine with air to create an explosion due to its high vapor pressure.

These explosive mixtures are so powerful that they can create spontaneous combustion or fire breakout.

Polymerization Properties

If you didn’t know, formaldehyde could join multiple molecules to create a bigger molecule through polymerization. Under some circumstances, this reaction can generate so much heat that it may result in an explosion.

Heat Sensitivity

An interesting fact about formaldehyde is that it’s sensitive or quite susceptible to heat. When subjected to high temperatures, formaldehyde can break down and release flammable vapors, resulting in a fire breakout.

What Is the Ignition Temperature of Formaldehyde?

Before we jump into the ignition temperature of formaldehyde, let’s clear out what it is.

The ignition temperature of a substance is stated as the minimum temperature required for the substance to catch fire when exposed to an external ignition source, for instance, a flame, excess heat, or a spark.

Now, moving on to the ignition temperature of formaldehyde, it’s about 122 to 144 degrees Fahrenheit or approximately 50 degrees Celsius. As you can understand, this temperature is insignificant, making it a piece of cake for formaldehyde to catch fire.

Apart from the flashpoint, there’s another term known as the ‘Auto-Ignition’ point. The auto-ignition temperature of a substance is when a substance spontaneously combusts without any external ignition source.

Ignition Temperature of Formaldehyde

And unfortunately, formaldehyde has an auto-ignition point as well. Under the standard room temperature and atmospheric pressure, the approximate auto-ignition temperature of formaldehyde stands at 430 degrees C or 806 degrees F.

However, there’s a catch.

In case when formaldehyde is accumulated in an enclosed space, the gas concentration increases, increasing its flammable content and lowering its auto-ignition temperature.

It can even drop to about 260 degrees C at a concentration level of 70% in the air! And if the formaldehyde is stored in a gas cylinder, the auto-ignition temperature drops even more.

How Hazardous Is Formaldehyde?

Well, the above contents made it clear that formaldehyde is quite hazardous when it comes to combustion, but how much?

As you already know, formaldehyde can easily ignite when exposed to an ignition source or even heat and turn into intense fires and explosions. When combined with oxygen in the air at atmospheric pressure, it creates explosive composites.

According to reports and studies, the range of flammability of formaldehyde ranges from 12.5 to 80% in terms of volume. However, the 65-70% formaldehyde-air mixture concentration is the most easily and quickly flammable. 

Besides, when it comes to the permissible exposure limit or PEL of formaldehyde, the acceptable exposure is 0.75 ppm averaged over a work shift of 8 hours. This must not be outdone during any 15-minute work session. 

Hazardous Is Formaldehyde

So, besides being a human carcinogenic substance, formaldehyde also has a high fire hazard!

To minimize the risks of ignition from formaldehyde, it’s crucial that you follow proper safety protocols when using, handling, or merely storing the substance. Here are a few tips for your safety −

  • Be mindful to store formaldehyde in a well-ventilated place away from any source of combustion or ignition.
  • When handling this toxic flammable substance, remember to wear gloves, goggles, and respirators.
  • While many forget about this, it is important to ensure all wiring and electrical equipment are properly grounded and maintained accordingly. Also, be careful only to use lab equipment approved for use with formaldehyde.
  • Avoid storing formaldehyde close to materials like acids, bases, and oxidizers, as they may react, and a profuse fire may follow through.
  • Try your best not to make any spills when handling formaldehyde. However, in a spill occurrence or leak, use absorbent materials and chemical spill kits to limit the fumes spread and reduce combustion risk.

How Do You Put out a Formaldehyde Fire?

Yes, formaldehyde is flammable, and it’s easy for formaldehyde to easily contribute to a fire or even cause it. But even if so happens, don’t panic!

Breathe in and out for a couple of seconds and take immediate action to prevent the fire from spreading. Let’s list out the steps for you.

Step 1: Quickly Alert Others

Before you start taking any fire extinguishing steps, as soon as you comprehend the fire situation, inform everyone inside the building and ask them to leave right away. Simultaneously, it is crucial that you call the fire department.

Step 2: Shut off the Supply

The next step is to cut off the formaldehyde supply. This will stop the fire from spreading if the substance source is a container or tank. You can shut off the power source by closing valves or turning off switches.

Step 3: Let the Fire Burn Itself, If Possible

Under certain circumstances, letting a formaldehyde fire burn itself out may be safer since it can be quite a challenge to put out. However, only take this course in case of a minor fire.

Step 4: Use Dry Powder or a CO2 Fire Extinguisher

Carbon dioxide or dry powder extinguishers can be a good way to put out minor flames efficiently. So, in case of quick-fire extinguishing, you can use these extinguishers without a doubt.

Such extinguishers work by smothering the flames and halting the oxygen supply. Also, sweep the extinguisher from side to side while also aiming toward the firebase.

Step 5: Cool the Area Using Water Spray

The next step is to cool the surrounding area of the ignition to prevent it from spreading. To do this, you can use water spray.

However, remember that you shouldn’t apply water directly to the flames but only to the surroundings; otherwise, the water can cause the formaldehyde to vaporize and spread out the flames even more.

Step 6: Immediate Evacuation

If the fire is too large and nothing is stopping it rather spreading rapidly, your best bet is to evacuate the fire zone immediately.

Can a Formaldehyde Explode on Fire?

Before we start this discussion, you should be able to differentiate the two terms- flammability and explosiveness. Yes, they are different properties of a material.

But how?

Formaldehyde Explode on Fire

The term ‘flammability’ describes the ability of a substance to catch fire and continue to burn in the presence of a flame or spark.

As for flammable materials, their characteristics include low flash points or the minimum temperature at which they will ignite and keep burning with an external ignition source.

On the other hand, the explosiveness of a substance refers to its capacity to quickly dissipate energy in the form of heat and gas, leading to a ruckus explosion.

These materials rapidly release their stored energy when exposed to an external stimulus, whether friction or heat, since they have such a high potential energy content.

Formaldehyde itself is not explosive and doesn’t typically explode on fire. But that’s not it; it may contribute to a fire if it reacts with another flammable substance.

You should know that with a lower flammability rate of 12.5% to a higher flammability limit of 70-80%, formaldehyde with high concentrations can easily form explosive mixtures with air. Nonetheless, it isn’t handled more generically for commercial purposes!

Is Peppermint Oil Considered a Flammable Substance?

Peppermint oil is an essential oil that has several benefits, but is it flammable? Yes, it is. It is considered a flammable substance because it has a low flash point, which means it can easily catch fire. Therefore, it is important to store it in a cool, dry, and well-ventilated place, away from any source of heat or flame.

Frequently Asked Questions

1. Is 37% formaldehyde flammable?

The 37% formaldehyde solution is the most commonly found in chemical industries and is known widely as formalin. Yes, the solution is flammable when it comes in contact with heat. Besides, it may also catch fire when it mixes with the air.

2. What happens to formaldehyde when heated?

Formaldehyde is stable up to 150 degrees C. However, when it reaches an extreme temperature at about the pressure level of 30-400mm, it decomposes into carbon monoxide and hydrogen.  

3. Can formaldehyde explode?

Formaldehyde with higher temperatures can polymerize exothermically in no time and start an ignition. So, when exposed to heat or flame without precautions, formaldehyde can contribute to it and cause an explosion.

Wrapping Up!

Well, it’s safe to say that now you’re sure that formaldehyde is flammable. Since formaldehyde is widely used industrially, knowing about its toxic features, especially the flammability content, is crucial, that’s what all the hassle is for.

However, no need to worry! All you need to do is follow the precautions and take safety measures when handling formaldehyde.

Finally, here’s one advice, since formaldehyde has a low flash point, do not leave the substance unsealed or unattained when opened. Well, take precautions and work safely, and that’s a wrap!