Is it acceptable to enter an area with an air purifying respirator if gas tests show levels above the IDLH for respiratory contaminants?

Entering an area with levels of respiratory contaminants above the Immediately Dangerous to Life or Health (IDLH) threshold is highly unsafe, and using an air purifying respirator in such conditions is not acceptable. IDLH levels represent concentrations of airborne contaminates that pose an immediate threat to life or that would cause irreversible health effects. Air purifying respirators are designed to filter out specific contaminants but are ineffective in situations where the contaminant concentration exceeds IDLH levels; these devices cannot provide sufficient protection against life-threatening gases since they rely on having breathable air.

In environments where the concentration of contaminants is above the IDLH, a different type of respiratory protection, such as a supplied-air respirator (SAR) or self-contained breathing apparatus (SCBA), is required to ensure the safety of personnel. Therefore, it is critical that no one enters such an area without the appropriate equipment designed for those hazardous conditions.