Car Seat Safety Standards, Decoded
Car seat safety comes down to four cited numbers: your seat's own rear-facing/forward-facing/booster limits (set by the manufacturer, per AAP guidance), the 65 lb combined LATCH weight cutoff (NHTSA), the seat's expiration date (manufacturer-set, no single federal rule), and FMVSS 213, the federal crash-test standard every new seat must meet.
The one thing to know: The trigger to switch out of rear-facing is your seat's own printed height/weight limit, not your child's birthday — AAP guidance dropped the '2 years' framing in favor of 'as long as possible, to the seat's limit,' because many convertible seats now allow rear-facing well past age 2.
The four things to check
- When to switch from rear-facing — the seat's own limit, not a birthday, decides.
- The LATCH 65 lb weight limit — when to stop using the lower anchors.
- Do car seats really expire? — yes, and why.
- What FMVSS 213 covers — the federal crash-test standard.
Why we don't recommend used car seats
Crib Lab does not recommend secondhand car seats or cribs. A used car seat's crash history and expiration date are often unverifiable, and pre-2011 or recalled cribs (including all drop-side models) remain in circulation at yard sales and hand-me-downs despite being illegal to sell.
Shopping for a new car seat?
Search current convertible car seats on Amazon — we don't recommend specific models without a full certified-source review, so shop by these cited standards: FMVSS 213 (required), and the rear-facing/forward-facing weight limits that fit your child now.
Search convertible car seats on AmazonThis page is general reference information about published safety standards, not installation or medical advice for your specific child or vehicle.
Frequently Asked Questions
There isn't one number — car seats are governed by several: the seat's own printed rear-facing/forward-facing limits, the 65 lb combined LATCH weight cutoff, and FMVSS 213's crash-test certification. All are covered in The Baby Gear Safety Numbers.
Crib Lab does not recommend it. A used seat's crash history and true expiration date are frequently unverifiable, and a seat involved in even a minor prior crash can have hidden structural damage.
Every car seat legally sold in the U.S. must be manufacturer-certified to FMVSS 213 (and, since 2022, its side-impact addendum FMVSS 213a). Look for the certification label permanently affixed to the seat.