Abstract: A respiratory protective device is disclosed. The device is of a type which may be used by several persons for an extended length of time in a noxious environment. The invention is characterized by a source of oxygen-rich gas, a breathing bag means, a valving system to vent and replenish the breathing bag means, a breathing conduit loop having inhalation and exhalation manifolds and a means therebetween to deliver breathable gas to several users at the same time, and a scrubber to remove carbon dioxide from exhaled gas. Special features include a unique dual alternately active breathing bag means and an assist means for movement of exhaled gas through the scrubber.