Mine Safety and Health Administration Precious Metals Refining This interactive DVD is a three video set addressing some some safety issues of precious metals refining. Mercury is in our ore. When we recover gold and silver, we also recover mercury. Mercury is toxic, and elevated levels of it are harmful to the body. We have to protect our personnel from the hazards associated with it, and we have to protect the environment as well. This segment contains: Health Hazards and Controls in Precious Metals Refining 15 min