I use this hook specifically to help with dough kneading. The white coating started chipping off like others are saying...
and today I found the chipping in the dough and had to throw the whole dough away... very disappointed.
This is a big concern for me. I purchased a kitchen aid product to  cook food at home. But, it failed me big time.
I am not sure what chemical was used to coat this hook. This is not what I expect from a branded company.