According to the HAZWOPER regulation, Level _____ is the minimum level of protection to be worn when operating in an unknown environment.

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

Answer: (C)

In an environment where you don’t know what you’re dealing with, breathing air protection is the top priority. Level B protection includes a self-contained breathing apparatus or equivalent respirator, giving you a reliable, breathable air supply, and it pairs with splash-protective chemical-resistant clothing to guard the skin from potential splashes. This combination is the minimum that provides solid respiratory protection while still allowing movement and work, without the encumbering requirements of a fully encapsulating suit.

Level A would be more protective than necessary in most unknown situations, since it uses a fully encapsulating suit with SCBA. Level C relies on air-purifying respirators, which aren’t guaranteed safe in unknown atmospheres because contaminants and concentrations aren’t known. Level D offers no respiratory protection at all, which would be unsafe. So the minimum safe choice for an unknown environment is Level B.