Choosing Respirators Based on IDLH Situations

An obvious factor in selecting a respirator is whether the environment is immediately dangerous to life or health (IDLH). (You of course wouldn't send an employee into an IDLH workspace with equipment that would not fully protect the employee!)

OSHA provides a useful list of site characteristics and hazards that may influence the choice of respirator and separates them into IDLH and non-IDLH situations. You are looking at the portion of the chart with IDLH situations. As you can see, for situations with hazards such as oxygen deficiency and hazardous gas, vapor contaminants, and other highly toxic air contaminants, OSHA recommends a "full-facepiece, pressure-demand SCBA certified for a minimum service life of 30 minutes" or "a combination full-facepiece, pressure-demand SAR with an auxiliary self-contained air supply." For contaminated atmospheres in which workers must escape, OSHA recommends a positive-pressure SCBA, a gas mask, or a "combination positive-pressure SAR with escape SCBA."

To learn more about Respiratory Protection visit our Respiratory Protection Online Training web page.