Like most baby products, baby carrier safety depends heavily on the user. Whenever using any baby carrier it is important for baby to:
be visible to you - even in a back carry you should be able to see baby in your peripheral vision
be high on your body (close enough to kiss when on your front)
be snug and tight to your body
have a clear airway - you should be able to put two finger widths under baby's chin (baby should NOT be chin-to-chest)
be in a seated squat position with knees at or above bum - this position allows for baby's hips to develop properly
Carriers are cleaned and inspected regularly, but it is important for you to inspect the carrier for damage before each use. If there is any damage, do NOT use the carrier.
Your baby's safety is ultimately your responsibility. Please educate yourself on proper babywearing techniques and use the carriers in the way they were intended.