An unpowered respiratory protective headset for personal protective equipment, comprising: a respiratory mask, comprising: a flexible mask body having an interface section and defining a mask air inlet and a mask air outlet, said interface section being of a size, shape and material to form an air-tight seal around a nose and a mouth of a subject when worn; an inhalation valve disposed in said mask air inlet; and an exhalation valve disposed in said mask air outlet; and a hood comprising a hood body and a transparent face shield attached to said hood body, said hood being of a size and shape to be worn entirely over and enclose said subject's head and said respiratory mask while said subject is wearing said respiratory mask within said hood, wherein said hood defines an air inlet and an air outlet spaced apart from said air inlet, wherein said hood further comprises an inlet filter disposed in said air inlet and an outlet valve disposed in said air outlet, wherein said air inlet, said mask air inlet, said mask air outlet and said air outlet are configured relative to each other to direct air flow across an inner surface of said transparent face shield to prevent or reduce fogging of said transparent face shield during inhalation and exhalation by said subject when said unpowered respiratory protective hood is worn, wherein said mask air outlet is attachable to and detachable from said air outlet or wherein said mask air outlet is permanently attached to said air outlet, and wherein said air inlet is disposed on a region corresponding to a top region of said hood. a respiratory mask, comprising: a flexible mask body having an interface section and defining a mask air inlet and a mask air outlet, said interface section being of a size, shape and material to form an air-tight seal around a nose and a mouth of a subject when worn; an inhalation valve disposed in said mask air inlet; and an exhalation valve disposed in said mask air outlet; and a flexible mask body having an interface section and defining a mask air inlet and a mask air outlet, said interface section being of a size, shape and material to form an air-tight seal around a nose and a mouth of a subject when worn; an inhalation valve disposed in said mask air inlet; and an exhalation valve disposed in said mask air outlet; and a hood comprising a hood body and a transparent face shield attached to said hood body, said hood being of a size and shape to be worn entirely over and enclose said subject's head and said respiratory mask while said subject is wearing said respiratory mask within said hood, wherein said hood defines an air inlet and an air outlet spaced apart from said air inlet, wherein said hood further comprises an inlet filter disposed in said air inlet and an outlet valve disposed in said air outlet, wherein said air inlet, said mask air inlet, said mask air outlet and said air outlet are configured relative to each other to direct air flow across an inner surface of said transparent face shield to prevent or reduce fogging of said transparent face shield during inhalation and exhalation by said subject when said unpowered respiratory protective hood is worn, wherein said mask air outlet is attachable to and detachable from said air outlet or wherein said mask air outlet is permanently attached to said air outlet, and wherein said air inlet is disposed on a region corresponding to a top region of said hood.