Abstract: An improved respirator system which protects the head of the operator while allowing excellent visibility and improved breathing conditions in a contaminated environment is disclosed. The system includes a hose mask with facepiece having a lens which provides improved visibility to both sides, as well as above and below the operator. The facepiece is provided with a seal around the head portion of the wearer with connection through a suitable hose ventilating system to a source of uncontaminated air at atmospheric pressure. The respirator is of the class B type, in which air is brought into the lungs from a source of uncontaminated air at ambient conditions through the bodily breathing function of the operator alone, without the use of an air compressor or a supply of compressed air.