Are you selling them as a supply for others to use?
But then again, look at it this way. You need a CoC from suppliers, what if you had a batch of something that turned out to have a flaw in it or was in some way hazardous. if you kept no records or didn't have some kind of labeling how would you know the origin of the flawed something, It's kind of trickle down and up responsibility. Your customers would need to be notified when you found out there was a problem and your supplier would need to be notified.
If you are selling something that you are advertising, describing as for ultimate use for children then it is perceived as a "children;s product".