Which PPE level is appropriate for known substances with less hazard and uses an air-purifying respirator?

• A. Level A
• B. Level B
• C. Level D
• D. Level C

Answer: (C)

Choosing PPE depends on how hazardous the substance is and whether the air can be cleaned by filtering. When the substance is known and its hazard is relatively low, an air-purifying respirator can remove the contaminants from the air you breathe, so you don’t need a self-contained breathing apparatus. Level C combines a protective clothing ensemble with an air-purifying respirator and appropriate eye protection, and is used only if the atmosphere has enough oxygen and the contaminant concentration is within what the respirator cartridges can handle. Levels that use SCBA provide the most protection and are reserved for unknown or highly hazardous vapors or oxygen-deficient conditions, while Level D is just basic work attire with no respiratory protection. Thus, for known substances with less hazard and the use of an air-purifying respirator, Level C is appropriate.