Car Seat Myths: “Survival Gap”

(Last Updated On: July 7, 2023)

Most of the time, we’re loathe to join discussions around viral shares that aren’t based on the CPST curriculum or that lack data to support the assertions made in the posts.  In many instances, these types of posts come from well-intentioned CPSTs or CPS advocates who might work alone.  They might see something out of context that gives them pause and leads them to connect the dots in a new and untested way, then go ahead and share that information in a way that causes needless panic among caregivers.

We’re set up a bit differently, our team of amazing CPSTs works together pretty much all the time.  We fact check each other and stick to the basics so we can help caregivers keep their children safe

Frankly, we don’t find this kind of post useful or particularly educational.  As you know, we’re pretty boring around here when it comes to information.  We follow manufacturer instructions and federal safety standards for the United States. We refer caregivers to their car seat’s manual, or to the manufacturer directly if they have questions that we’re unable to answer using these resources and our own knowledge of these resources.

In other words, we don’t invent things. We like to think that this consistency is a part of why caregivers trust us to help them keep their children safe in the vehicle.

The latest post in this series of viral posts uses part of the ECE R129 child seat standard in Europe to create something called the survival gap.  The post goes on to suggest that because seats sold in the United States and Canada aren’t tested to this standard (which, by the way, is just one piece of a fairly lengthy and technical standards document), they somehow aren’t safe.

The gap that’s part of this ECE standard is from a vertical line originating in the vehicle seat bight to the vehicle seat in front of the car seat.  It is not measured from the car seat or from the child in the seat.

Key Point: many of the things required per the ECE standard are different than the requirements of our FMVSS standard here in the United States (and CMVSS in Canada).  We talked about this in a 2016 article, it’s still true today.

Reminder: car seats sold in the United States must meet or exceed our federal safety standard FMVSS213 and car seats sold in Canada must meet or exceed CMVSS213.  The small piece of the regulation that’s at the heart of these viral posts does not apply to car seats that are sold in the United States or Canada.

A Brief History of R129

The UNECE R129 standard replaced the previous standard: ECE R44/04.  Feel free to read up on this standard: https://unece.org/sites/default/files/2021-05/R129r4e.pdf

The gap was decreased from 55 cm to 50 cm as part of this update.  In ECE R44 (the regulations immediately preceding R129) the gap was still there but was bigger.

The gap is between the vehicle seat back and the back of the vehicle seat in front 0f it.  The viral post seems to suggest that the gap is measured differently.  It is not.  It is back of vehicle seat to back of vehicle seat.

Other updates between U44 and R129 include:

  • A classification for child seats based on the child’s height
  • UN R129, examines side crashes in addition to frontal crashes
  • Q-type dummies are used with the crash tests, in R44.
  • The new R129 standard extends the mandatory rear facing travel time until a child is 15 months old.

Section 6.6.4.4.1.1.1 of the updated standard includes this illustration along with a list of regulations around the setup of a forward facing car seat during testing.  This is on page 36 of a 146 page document.  In other words, it’s one small piece of the puzzle that makes up a full set of safety standards that are unique to each country or region.

No description available.

The European car seat test is configured so that the seats are tested on rigs that have another vehicle seat or bar 50-55 cm in front of them (depending on which regulations are being followed for the test).

The 50 or 55 cm represents the maximum that the crash test dummy’s head is allowed to move forward during testing. If a dummy’s head exceeds that 50 or 55 cm the seat will fail the test.

What’s Different Between the EU and the United States

The standard car seat manufacturers follow in the United States, FMVSS213, has only a bench seat, it does not have a vehicle seat in front of the testing location.  This gap is not part of that standard, though car seats that are sold in the United States do include top tethers that help to limit head excursion in a significant way.

What this Means

European forward facing car seats aren’t tested with less than a 50 or 55 cm gap (depending on which standard is being used for testing), so we don’t know how a seat will perform with a smaller gap.

For that reason, our EU team advocates for a 50 or 55 cm space between the rear vehicle seat and the vehicle seat in front of it (NOT 55 cm from the child seat to the seat in front, though this is a very, very common misconception) for forward facing seats (both harnesses and boosters).

Rear facing seats tested under the ECE R44 standard do not need to have the same gap.

Any car seat tested under the United States FMVSS 213 standard isn’t tested per this standard at all.  That doesn’t mean your child’s car seat is any more or less safe than car seats sold in the EU — they’re just all tested to a different standard that’s unique to that country.

Again we will say:

All Car Seats Sold in the United States Meet or Exceed FMVSS213

All Car Seats Sold in Canada Meet or Exceed CMVSS213

Many nations or regions have regulations around car seats.  Each of those regulations differ a bit, so the standard for one area may not be the standard for another.  That’s part of this situation as well.  Best practice remains as follows:

Follow your car seat manufacturer’s instructions.  Install the seat properly (that definitely includes a top tether for all forward facing installations), and use it properly on every ride.