IDLH Concentrations
IDLH exposure concentrations have been established by the NIOSH/OSHA Standards Completion Program (SCP) as a guideline for selecting respirators for some chemicals.
The definition of IDLH varies depending on the source. For example:
- The Mine Safety and Health Administration Standard (30 CFR Part 11.3(t)) defines IDLH conditions as those that pose an immediate threat to life or health or that pose an immediate threat of severe exposure to contaminants such as radioactive materials that are likely to have adverse cumulative or delayed effects on health.
- The NIOSH Pocket Guide to Chemical Hazards
defines IDLH concentration as the:
"... maximum level from which one could escape within 30 minutes without any escape-impairing symptoms or any irreversible health effects." - The American National Standards Institute, Inc. (ANSI) defines IDLH as:
"any atmosphere that poses an immediate hazard to life or produces immediate, irreversible debilitating effects on health."
Regardless of their exact definition, all IDLH values indicate those concentrations of toxic substances from which escape is possible without irreversible harm should a worker's respiratory protective equipment fail.
At hazardous waste sites, IDLH concentrations should be assumed to represent concentrations above which only workers wearing respirators that provide the maximum protection (i.e., a positive-pressure, full-facepiece, self-contained breathing apparatus [SCBA] or a combination positive-pressure, full-facepiece, supplied-air respirator with positive-pressure SCBA) are permitted.
Knowledge Check Choose the best answer for the question.
3-3. At hazardous waste sites, what should IDLH concentrations be assumed to represent?
You forgot to answer the question!