Is Styrofoam Flammable? (All You Need to Know)

Styrofoam is one of the many common materials that we use in our daily lives. Its excellent insulating abilities make it an ideal insulator from food containers and coffee cups to walls and pipe insulations.

Styrofoam has several distinct properties that we should be aware of when handling it. You can know about those properties and other relevant information below.

Is styrofoam flammable?

Styrofoam is a highly flammable material at high temperatures and can catch fire when exposed to open flame. Although styrofoam can withstand some heat but exposure to higher temperatures would cause it to melt and catch fire. Styrofoam burns with sooty smoke, releasing toxic chemicals.

Styrofoams come in several variants such as Pink and Blue insulation boards. Despite being quite identical as insulators, the boards have distinct usages.

Blue styrofoam insulation:

Blue foam boards are styrofoam insulation boards that have thin plastic films covering their polystyrene core. Its rigidity allows it to be used on exterior walls to provide insulation and as reroofing for its high compressiveness.

Blue foam insulation boards are generally prone to catching fire. Therefore, they must be protected with a flame barrier when installed in living spaces.

Blue Boards should not be used in areas of high temperature since they have a maximum usage temperature of 165° F. But recently, fire-retarded blue foams are also available in the market at a higher cost.

Pink styrofoam insulation:

Pink foam boards are styrofoam insulation boards consisting of drainage channels on the surface along with a filtration system that prevents soil clogs.

They are commonly used on foundation walls for tighter insulation between the board and the adjacent surface.

Pink foam insulation boards are generally highly combustible as well. However, several fire-retarded pink foams are available and have maximum usage temperatures as specified by the manufacturer.

Is styrofoam fireproof or a fire hazard?

Styrofoams catch on fire with an open flame. Despite its heat resistance, styrofoam should be kept away from sources of heat, and its disposal should not be done through incinerators.

Styrofoams have exhibited behaviors of being a fire hazard. However, manufacturers of styrofoam claim that proper installation reduces the chance of fire hazards. Thus Styrofoam insulations are often coupled with a flame barrier, such as drywall.

At what temperature does Styrofoam catch on fire?

Styrofoams begin losing their rigidity and melt at 212° F. At a threshold of 680° F, Styrofoams become flammable and catch on fire upon contact with a spark.

At 800° F, they catch on fire by themselves. Therefore, Styrofoams can be used as an effective insulator if it is protected by a flame barrier and prevented from coming in direct contact with fire.

How to make polystyrene fireproof?

To combat the flammability of polystyrenes, their fire-retarded variants are available in the market. However, if you wish to make your own fireproof polystyrene, you can use a Fire Retardant Intumescent Clear Coat through the following steps:

Buy a suitable coating:

There are several types of Fire Retardant coats available in the market but make sure you buy one that is specifically for polystyrenes, such as FPCC Clear Fire Retardant by RDR Technologies.

Paint or seal the polystyrene surface:

Intumescent coats work best over paints, especially Latex paints. Therefore, you need to paint the surface before applying the coat.

The coat loses its effectiveness if it’s mixed with wet paint. Thus, the surface of the paint must be dried before applying the coat.

Dry the surface before applying:

Make sure the surface is clean and dry before applying the coat. The coat will lose its effectiveness if it dissolves with the paint layer.

Coat the surface:

Apply multiple thin layers of coat instead of a few thicker layers. The coating volume depends on how thick you want each layer to be.

Also, avoid applying very thick layers, because the coat will slough off and not dry properly.

Is styrofoam heat resistant?

Styrofoam is heat resistant to a good extent. Its heat resistance allowed it to be conventionally used as coffee cups and hot food containers since it kept the food insulated inside, and protected fingers from burns.

Styrofoams tend to break down and release harmful toxins and chemicals as well as lose their rigidity in places that have a maximum temperature above 212° F.

However, Styrofoams can be used well above the limit if it has been coated with fire retardant coating or flame barriers.

Styrofoam becomes flammable at 680° F, so it is heat resistant to a decent degree until that point.

Is it safe to burn Styrofoam?

It is not safe to burn Styrofoam as it poses several threats to health. Burning Styrofoam releases toxic gases that cause severe issues to health when inhaled.

The fumes produced contain styrene, carbon monoxide, and other toxins as well that are harmful to humans and the environment.

Styrene gas is notorious for adverse impacts on the nervous system and can cause long-term problems.

Carbon monoxide, on the other hand, causes severe damage to internal organs when inhaled and can cause you to lose consciousness upon inhaling in large amounts.

Apart from these gases, the toxic gases released are carcinogenic and can also lead to lung diseases and permanent lung damage.

What happens if you burn Styrofoam?

Styrofoam is not fully combustible and produces several byproducts when burnt. Burning Styrofoam releases a sooty and slightly oily smoke. That is dangerous for both humans and the environment.

Such conditions make it difficult to dispose of Styrofoam. Burning Styrofoam is, therefore, the least appropriate way to get rid of it.

One method of disposal is dumping it for recycling or burying it. Styrofoams can be reused as well and can be used for their insulating properties.

Does Styrofoam burn or melt?

Styrofoam can both burn and melt but it is more prone to melting than burning. You will notice that Styrofoams start to deform around 212° F and effectively melt as the heat increases.

Upon its exposure to heat, it will lose its shape and remain in that deformed molten state till 680° F. But even after that point, it will not catch fire unless it comes in contact with a spark or open flame. It will only catch on fire by itself from 800° F onwards.

Final Thoughts

Styrofoam is flammable when exposed to open flames. They usually melt at high temperatures and need to be coated with a flame barrier. Their heat resistance makes them good insulators for domestic and industrial uses. Burning Styrofoam releases toxic chemicals harmful to the environment.