Seat Belt Extenders: NEVER for Car Seats or Boosters or Non-Obese Adults
What is a Seat Belt Extender?
A seat belt extender is an extra piece that goes between the male and female ends of the seat belt to make the seat belt longer.
Extenders were initially designed for obese adults to allow them to buckle up in situations where the belt was otherwise too short to go around their body.
Now, extenders are often advertised to “solve” lots of problems – ranging from making it easier to buckle a child in a booster, or to make the seat belt fit differently on a pregnant woman.
When is it SAFE to use a Seat Belt Extender?
The only time it is safe to use a seat belt extender in a car is when both of the following criteria are met:
- The person using the extender is an obese teenager or adult whose body size is such that the seat belt can not be buckled without the use of an extender.
- The extender is obtained directly from the vehicle manufacturer (not from Amazon, eBay, Walmart, AliExpress or other stores/websites).
When is it DANGEROUS to use a Seat Belt Extender?
1.With any car seat
2.With any booster seat
3.With any child
4.With any adult whose body size allows for the seat belt to be buckled without the need for an extender
5.With any pregnant woman (unless her body size otherwise does not allow the buckling of the seat belt)
6.To help someone buckle up when a car seat or booster is blocking someone’s access to their seat belt buckle (a different car seat or booster needs to be used, or the person 7.needs to ride in a different spot in the car)
8.To help an adult who has difficulty buckling up – for example someone with arthritis or mobility issues.
What makes seat belt extenders DANGEROUS?
Extenders can fail in a crash – leaving the person completely unbuckled.
The extender must match the buckle used in that specific vehicle.
Just because you can get the seat belt to click into the extender does NOT mean the seat belt will stay buckled in a crash when several thousand pounds of force are applied to the buckle. And if the seat belt unbuckles in the crash, then not only are you in grave danger, so is everyone else in the car as you can fly on top of them.
In a crash everything becomes much heavier due to the G-forces (force of gravity). You’ll effectively weigh your usual weight times however many G’s are in the crash. In a 30mph crash like they use to crash test car seats, there are about 25 G’s. A 250 pound adult in a crash with 25 G’s is going to feel like they weigh 6,250 (250 x 25 = 6,250). Their body will put 6,250 pounds of force on the seat belt and the extender.
If you get a seatbelt extender from a specific vehicle manufacturer – let’s say Ford, for example – you can not assume it will work in all Ford vehicles. The Ford Taurus may use a different seat belt buckle than the Ford Explorer – and therefore the extender would be different for these two Ford vehicles.
Extenders can change the geometry of the seat belt on the body.
Extenders make the buckle stalk (the female end of the buckle) longer… sometimes a lot longer. As the female end gets longer it moves the buckle from the side of your hip (where it should be) farther and farther towards the middle of your body. As the buckle moves closer to the center of your body, the shoulder belt moves farther out of position, sliding onto your arm instead of resting on your collar bone. The shoulder belt has a very important job in a crash – it has to keep your head and chest held tight so that they don’t move too far forward which can cause your head to hit hard parts of the car. If the shoulder belt is on your arm – where it should never be – then your head, neck, and torso will not be well protected as the shoulder belt won’t be able to hold you back. You’ll jack-knife over yourself, making it likely that you will hit your head on something hard – like the back of the front seat, the doorframe, or the window.
With a large adult – one who otherwise couldn’t buckle their seat belt without using an extender – the use of an extender that is as short as possible to just allow them to buckle the seat belt will not change the shoulder belt fit significantly as the seat belt buckle will remain close to the side of the body rather than in front and towards the center of the body.
The smaller the person using a seat belt extender, the less it will take for the shoulder belt to slide off the arm – and the greater the risk to using a belt extender.
