That they actually have to be trained to do it! (recommendations 9 and 10)
www.nice.org.uk/guidance/index.jsp?action=download&o=35572
It isn't published yet but you can view the draft. Even when it is published it could take a while before it is fully implemented...
It actually covers wide range of issues to do with pregnant, breastfeeding and small child health - not just training of professionals - but I just mentioned that as the duff advice given to women is a huge bug-bear to many MNetters. Recommendation 14 says parents should have access to independent advice about formula including the risks.