My carriers are all sewn with extra strong thread on any stress points using a method of stitching called “bar tacking”. This is a very strong type of stitch that spreads the weight put on it evenly so there’s no unnecessary strain put on the fabric. It feels neat to the tough and looks smooth giving a clean finish.
They have not been tested in a lab due to there being so many options available, each different design/option/fabric would need to be tested! They have however been rigorously tested by me with weights of up to 5 stone. My test carrier happily hung in a very strenuous position for the straps for days through wind and rain with no problems and even a good bounce proved a simple task for the stitching. The carrier is holding 5 stone of soil.
Any carrier should always be checked over thoroughly before each use to check for signs of wear or damage.
How to tie your Mei Tai with a legs out baby