How Heat Resistant Is Plexiglass? (Answered)

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Plexiglass, a plastic material that shares several properties with glass, has a wide range of uses, such as in windowpanes and shower enclosures. But when it comes to heat, plexiglass may not stand up to the competition. So, just how heat resistant is plexiglass?

Plexiglass can only stand temperatures of up to 200–500 °F, depending on its formulation, whereas glass can stand temperatures of up to 2,600–2,800 °F. Plexiglass can melt and burn if exposed to intense heat, and it may produce toxic fumes such as carbon monoxide and carbon dioxide.

Let’s take a closer look at how heat resistant plexiglass is, including whether it melts or burns, and whether glass is a safer choice for situations where high heat is likely.

Does Plexiglass Melt?

Colorful pieces of plexiglass

Yes, plexiglass can melt if exposed to high temperatures. 

Plexiglass has a lower melting point than glass (the latter has a whopping melting point of around 2,600–2,800°F), which can limit its use in applications that require high-temperature resistance.

For example, plexiglass may not be suitable for use in industrial settings, because high temperatures tend to be very common with industrial machinery. 

It’s important to handle plexiglass with care to avoid exposing it to high temperatures. If plexiglass is exposed to high temperatures, it can become deformed, warped, or even melt.

When drilling or cutting plexiglass, you must use appropriate tools and techniques to prevent the plastic from overheating and melting.

Does Plexiglass Burn?

Yes, plexiglass can burn, and it can even be dangerous when it does — even beyond the fact that it will be hot to the touch. The extent to which plexiglass burns depends on a number of factors, such as the specific formulation of the plastic, the thickness of the material, and the intensity of the heat source.

When plexiglass burns, it can release potentially harmful fumes like carbon monoxide and carbon dioxide. The extent and composition of the fumes depend on the specific formulation of the plexiglass.

Handle plexiglass with care and keep it away from heat sources and open flames. It’s also a good idea to have first aid options and safety equipment, such as fire extinguishers, on hand.

Is Plexiglass Flammable?

Yes, plexiglass is flammable, and the level of flammability depends on the specific formulation of the material.

What Is the Highest Temperature Plexiglass Can Withstand?

Although all of the aforementioned situations depend in part on the specific material and how it was formed, plexiglass is generally flammable at around 200-500 °F, so it’s essential to never expose it to temperatures that get close to this.

If you don’t know what specific temperature your plexiglass will be flammable at, keeping everything below 200 °F to be safe.

Safety Measures to Take With Plexiglass

If you have plexiglass around, you should make sure it’s in a place where it’s unlikely to be exposed to high heat to avoid issues. However, accidents happen, so it’s also good to have some safety measures in place.

The first one is to have a smoke alarm (on Amazon) present. An alarm will help you detect any problems before they get to the plexiglass, hopefully preventing it from releasing toxic fumes. Of course, a smoke alarm is recommended in every building!

The second measure is to have a fire extinguisher (on Amazon) handy. The hope is that you’ll never have to use it, but in the event that you do, it may save lives.

Lastly, it’s also a good idea to have a carbon monoxide alarm (on Amazon) — just in case. Because plexiglass can emit toxic fumes when exposed to high heat, and carbon monoxide poisoning can be fatal, this alarm can let you know long before the fume approaches toxic levels so that you can take the appropriate action.

Is Glass a Safer Choice?

Blank black glass signplate on textured wall mockup

If the item in question is going to be exposed to high heat, then yes, glass is a safer choice due to its extremely high melting point. However, this is very dependent on your individual situation.

Plexiglass isn’t inherently unsafe. It just isn’t the appropriate material to use in a place that may be exposed to temperatures above 200 °F.

Of course, it’s usually rare that an average building would be. Your typical house, for example, will likely never be exposed to temperatures that high, and plexiglass has other amazing safety features, such as being shatter-resistant.

For most, the heat resistance therefore isn’t a concern. That said, those working with high heat intensity must take care.

Final Thoughts

All in all, it’s important to bear in mind that plexiglass is flammable and isn’t heat resistant, since it often can’t withstand temperatures higher than 200 °F. If you’re looking for a material that can withstand high, intense heat, then it’s probably better to go with regular glass.

However, plexiglass has some great properties of its own, such as its insulation capabilities and shatter resistance, so it’s important to think about your needs and the specific situation.

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