Universal precautions refers to the practice, in meicine, of avoiding contact with patients' bodily fluids, by means of the wearing of nonporous articles such as medical gloves, goggles, and face shields. Medical instruments, especially scalpels and hypodermic needles should be handled carefully and disposed of properly in a sharps container. Pathogens fall into two broad categories, bloodborne (carried in the body fluids) and airborne. Standard universal precautions cover both types.