I would say a prayer about it and rest assured that they will not injur any one. I never thought about that but I had a friend who said her neighbor brought her baby over because she wouldn't stop crying, my friend noticed two fingers turning blue, on close inspection she found one of mom's long hairs would around them. If a hair would cause problems I'm sure that thread could be worse. Makes me glad that when I tried the other day it kept messing up and I gave up. but polyester thread would be just as bad, have you ever tried to break it?