With so many potentially dangerous chemicals how safe is chemical engineering?

feldspar

I have this friend who wants to study chemical engineering and has a criminal record, he is completely rehabilitated and not a danger to society but he's worried employers might make snap decisions about him if they get access to his record. Is he making the right decision or should he rethink his career choices?

Oil refineries obviously have strict safety procedures, how often do they do background checks?

What about pharmaceuticals or general goods like tires and sugar?