What is the PF for a pressure-demand SCBA?

What is the PF for a pressure-demand SCBA?

• A. 1000
• B. 100
• C. 10000
• D. 10

Answer: (C)

Protection factor is the ratio of contaminant concentration outside the respirator to the concentration inside the wearer’s breathing zone. A pressure-demand SCBA keeps the facepiece at a positive pressure, so any small leaks push air outward rather than letting contaminated air in. This effectively minimizes inward leakage and yields a very high protection factor—ten thousand. That level reflects the exceptionally high protection provided in hazardous atmospheres, far surpassing other respirators that offer lower protection factors.

Protection factor is the ratio of contaminant concentration outside the respirator to the concentration inside the wearer’s breathing zone. A pressure-demand SCBA keeps the facepiece at a positive pressure, so any small leaks push air outward rather than letting contaminated air in. This effectively minimizes inward leakage and yields a very high protection factor—ten thousand. That level reflects the exceptionally high protection provided in hazardous atmospheres, far surpassing other respirators that offer lower protection factors.