Every once in a while, a meme goes around on social media that catches my attention. For some reason, this myth has become wildly popular and everyone seems to be very excited about the implications and benefits of this information.
This got me wondering. Is this true? Because if so, I had no idea and what a great hidden trick! If not, then it is probably sort of dangerous for people to be spreading it to others when there are devices that are specifically created to help break windows in an emergency.
MYTH: A vehicle headrest is left deliberately detachable and sharp so that it can be used to break a vehicle’s window and the glass of a vehicle window is easily broken from the inside.
I’m going to break this down into two parts: the headrest and the window.
Let’s look first at the major function of a headrest. It’s part of the restraint system and anyone who is using a backless booster or a seatbelt alone, absolutely should have a headrest. It is critically important for preventing neck hyperextension in a crash and could be the difference between a spinal cord injury and just normal whiplash. So that’s its primary function. Now what about the window breaking?
I did some poking around the internet and found a very long (and dull) document about headrest function and design written by NHTSA. Despite being at least 10 pages long, there is nothing in it about the potential to break vehicle windows.
The other thing that leads me to believe that this part of the myth may not be true is that not every vehicle has removable headrests. It seems like if this was part of an industry standard, then there wouldn’t be these outliers with non-detachable headrests. And I took off the headrests of both of my cars and sadly, neither were sharp.
I’m going to go ahead and say that a vehicle headrest isn’t left deliberately detachable or sharp for window breaking. It is potentially a major bonus (if it can indeed break a window), but it is not a part of the primary design of the vehicle seat in anything I’ve found.
Now, to the second part: whether vehicle glass easy to break. I really felt strongly that the answer to that was no, but there is definitely a lot to learn about vehicle glass.
FMVSS 205 — This sets clear standards for automotive window transparency and the strength of automotive glass required to keep occupants inside the vehicle during accidents. That right there, sounds like strong glass, right?
The windshield is made of laminated glass, and the side windows are tempered glass. Laminated glass is two layers of glass with a layer of polyvinyl butyral in the middle. The PVB allows the glass to absorb energy and makes it stronger than typical glass, which both helps maintain the roof space in a roll over and prevents passengers from being ejected through the windshield. I strongly suspect that laminated glass would not yield to a vehicle headrest prong.
Tempered glass is glass that is heated and quickly cooled. What this does is allow the outside layers, which are cooler, to contract and compress, but the inside, which is still hot, is able to expand, making the glass extremely strong both when put until tensile and compressive forces. Tempered glass is somewhere between 5 and 10 times stronger than standard glass. While this process makes strong glass, it does make the edges weaker, which is why those edges are ground and smoothed down (look at the top of your windows to see what I’m talking about). Might this weakness be how a vehicle headrest can break a vehicle window? Arguably yes, but! let’s look again at our myth.
It states that the vehicle headrest is deliberately detachable so it can be used to break a vehicle window, which we’ve already found to be dubious at best, and that the vehicle window is easily broken from the inside. The way that the tempered and laminated glasses are created is entirely for the opposite purpose. These glasses are intended to be exceptionally strong: to hold the frame of the car stable, to keep occupants inside, to withstand the concussive force of the passenger airbag. Nothing about the design of laminated or tempered glass is in any way easy to break.
Verdict: This myth, as it is written, is BUSTED.
Now, before you comment with the video of the woman breaking her window open with the vehicle headrest, which I have seen, let me clarify that I’m not saying that it is impossible. I’m simply saying that, per this meme, a vehicle headrest is not created with this intention in mind and that vehicle glass is very intentionally hard to break. More importantly, there are several tools on the market like the Resqme or an Emergency Window Hammer that will reliably and much more easily break your window open in a crash and you should absolutely have at least one of these in your car. Many will double as seatbelt cutters and could literally save your life in a crash involving water or a heavily damaged door.
In the end, I’m hoping that this meme will slowly die, or perhaps be replaced with one that includes information about belt cutter/window breaking kits so that more families don’t have to hope their headrests come off or that they can get the exact right leverage to break their window in an emergency. Let’s not rely on hoping that vehicle companies imagined this secondary benefit of a headrest and instead spend a few bucks for peace of mind and confidence that you have the ability to escape your vehicle if you’re trapped.