Fig. 2. Hood, face shield, and positive flow of oxygen. (Left ) SR-64 protective hood; (middle ) SR-64 hood with face shield made of plastic cloth and transparency film; (right ) oxygen (greater than 10 l/min) was delivered to mask with P3-level filter from a portable oxygen cylinder. A nonrebreathing mask with a reservoir bag was attached to the P3 filter. The oxygen flow rate should be adjusted according to different minute volumes.