Fume respirators with replaceable filter Designed as respiratory protection against fumes of various metals having an air contamination level not less than 0.05 milligram per cubic meter. Half mask Fits over the nose, mouth, and under the chin. Hood or Helmet Loose-fitting respirators that enclose at least the head. A light, flexible device covering only the head and neck, or head, neck, and showers is called a hood. If rigid headgear is incorporated into the design, it is called a helmet.
Blouses extend down to the waist, and some have wrist-length sleeves.
The enclosure includes a system through which clean compressed air is distributed around the breathing zone. It may include a head harness and connection for a breathing tube. Mist respirators with replaceable filters Designed as respiratory protection against mist of materials having an air contamination level not less than 0.05 milligram per cubic meter or 2 million particles per cubic foot. Mouthpiece respirators should provide a good seal, but they eliminate communication, may cause fatigue, and provide no eye protection. Therefore, mouthpiece respirators are certified for use as escape-only respirators.