Inflatable seat belts were primarily available on certain models of vehicles, they were discontinued after the 2020 model year for most manufacturers.
Inflatable seat belts combined airbags and vehicle seat belts into one high tech package, offering adult passengers an additional, passive level of protection in the event of a crash. The addition of air bags to some models of some vehicles offered an important level of additional protection for adult passengers. However, for all the protection that these lifesaving devices offered to adult passengers, they posed some challenges when it comes to car seat installation.
Airbags can be found in many places in modern vehicles. Image courtesy of the National Child Passenger Safety Board
Since airbags were first introduced in the 1980s, they have expanded beyond the front seat into almost all parts of the car. A glance around the interior of most modern vehicles reveals airbags on the dashboard, on the steering column, on the side pillars, and above the windows in the back seat.
Inflatable seat belts look and feel different than traditional seat belts.
Airbags are now making their way beyond those locations inside the vehicle on to vehicle seat belts.
Inflatable Vehicle Seat Belts vs. Traditional Vehicle Seat Belts
Unlike most seat belts, ISBs lock where the lap belt portion of the seat belt comes out of the vehicle.
Inflatable seat belts are different from traditional vehicle seat belts in both form and function.
Both inflatable seat belts and traditional seat belts work very well to protect adult bodies in car crashes. This video from Ford explains the technology behind inflatable seat belts.
Approved Car Seats (Updated 11/2023)
Because crash testing is expensive and takes time, car seat manufacturers are slowly testing their products with inflatable seat belts. Over the last few years, the list of approved car seats has grown and changed.
Here’s a list of the current car seat manufacturers in the United States that permit the use of inflatable seat belts with a car seat or booster seat.
Unless otherwise noted, these approvals only apply to Ford Motor Company’s (maker of Ford and Lincoln vehicles) inflatable seat belts in the United States and/or Canada.
Installing a Car Seat using an Inflatable Seat Belt
Inflatable seat belts are unique because their switchable locking retractor is down where the lap belt portion of the belt extends from the vehicle body. When installing car seats in a seating position with inflatable seat belts, the vehicle seat belt must be locked at this lower retractor, even if that car seat has built-in lock offs that are permitted for use with the inflatable seat belts.
To engage this locking mechanism, slowly pull the lap belt portion of the vehicle seat belt out completely, then allow it to retract back in. Sometimes this is easier to do after the seat is installed, but that will vary by car seat and vehicle. As always, it’s critical to follow the manual for both the vehicle and the car seat.
How ISBs Work Image courtesy of Moditech
Unfortunately, inflatable seat belts are currently still not approved for use in installing many car seats, nor have they been approved for use with all belt positioning booster seats.
The list of approved car seats and boosters is expanding, but we expect to see compatibility challenges for some time to come.
Alternative Installation Method
All car seats can be installed with either the vehicle seat belt or LATCH (when the child’s weight is low enough to allow the use of LATCH). If a vehicle has inflatable seat belts and the car seat prohibits the use of inflatable seat belts, one option is to install the car seat with LATCH instead. The only challenge with this scenario is that lower anchors have weight limits that the child may outgrow before they’ve outgrown their harnessed car seat.
Several car seats have lower anchor weight limits of 50 pounds. Many of these lightweight car seats may last until the child reaches a safe age for riding in a booster seat without ever needing to use a seat belt install!
Long lasting harnessed seats with high lower anchor weight limits
Installation Tips
Most of the time, vehicle seat belts lock at the retractor (the part of the vehicle where the shoulder belt attaches), but they’ll sometimes lock at the latch plate instead (the “male” part of the seat belt buckle). Inflatable seat belts will lock where the lap belt extends from the frame of the vehicle.
To engage the locking function, pull the lap belt portion out from the retractor inside of the vehicle frame until it has been fully extended, then the retractor will switch to the locked mode. Ensure that all of the slack has been fed back into the retractor for a snug car seat installation.
Changes and Updates
ISB pre-crash (left) ISB post-crash (right) Image courtesy of the Automotive Safety Program
As inflatable seat belts are added to more vehicles on the road, changes to the compatibility rules for car seats and booster seats are sure to follow. Stay up to date by referring to this article or reaching out to the car seat manufacturer for the latest policy on this evolving technology.
