I have had several students with the same issues. One of the last was a nurse and she checked with her Dr. who was also a photographer. These are his directions for her. Be sure you wear Nitrile gloves and other than that he did not forsee a problem.
Individuals vary with how sensitive they are to chemicals and so i always recommend these students check with their doctor.
On the other hand, i will not allow a pregant woman in my toning classes; these are some of the most toxic chemicals we use and i would rather be safe than sorry. Neither would i let them take a color printing class because of the nature of the chemcials.
As has been stated, good ventilation, gloves and a stool to sit on to save the legs.