I don't have any documentation in front of me, (some of my reference bks are
loaned out), but have asked about perms & bfing several times over 20 yrs,
and the answers I've received have always been that there should be no
contraindication that anyone can document.  Anecdotally, I had perms while
bfing my daughter and she graduated 4.0 grade point avg from high school a
few years ago, and appears otherwise intact, and I have known hundreds of
other bf moms who had perms, coloring, etc during lactation with no ill
effects noted to infant.

Personally, I would be more concerned about lactating moms getting silver
amalgam dental fillings.  I personally always got sick after having cavities
filled with amalgam, and didn't know until several years ago that it was the
mercury poisoning my system.  We had all the silver fillings replaced in my
daughter and myself a few years ago, and noticed definite health benefits.
 (Know it may be surprizing to those who live in countries where amalgam
fillings are no longer legal that they are still very common in the US)

Kathe Catone, IBCLC, LLLL   ([log in to unmask])