So what should you do?
1) Inspect visually for wear and tear. Loose threads, fraying?
2) Don’t be afraid to pull at seams and to be afraid of it ripping. Best it rips in your hand than when it has a precious cargo inside.
3) Don’t assume because it is new or from a well known company it is ok.
4) Inspect all buckles and webbing on ssc’s
There is a very helpful thread here on the babywearer forum which shows how to test different types of carriers: