Mary
My first question to you: When this mom found out she was pregnant did she
stop working?  Her fetus would have been at more risk to these exposures at
that time than through her lactating now.  What are the safety factors this
job is providing their employees so they are not put at a health risk?
I will be curious to see if others respond to you but my first thoughts are
if the job is offering protection to the employee than she should be able to
breastfeed.

Ann Perry RN IBCLC