Scientific Pump Repair

Hello, I would appreciate any insight you could provide. I have a small workshop at home that I would like to start repairing pumps for scientific and academic labs. The question/concern that I have is the potential for exposure to hazardous chemicals. My workstation is indoors. Are there any specific types of pumps that would be safer to work on than others, or put another way are there pumps that won't contain any traces of hazardous chemicals? Thank you.