APF for respirators: what APF is assigned to a dust mask?

APF for respirators: what APF is assigned to a dust mask?

• A. APF 50
• B. APF 10
• C. APF 5
• D. APF 100

Answer: (B)

The concept here is Assigned Protection Factor, which indicates how much a respirator can reduce your exposure when worn correctly. A dust mask, being a basic disposable filtering facepiece, provides a relatively low level of protection because it doesn’t seal as tightly as elastomeric or full-face respirators. Its APF is 10, meaning it reduces the contaminant concentration inside the mask to about one-tenth of the outside concentration, assuming proper use and fit. Higher protection devices—like full-face or powered respirators—have higher APFs, while very simple or loose-fitting devices have lower or different values. So, for a dust mask, the APF of 10 is the appropriate value.

The concept here is Assigned Protection Factor, which indicates how much a respirator can reduce your exposure when worn correctly. A dust mask, being a basic disposable filtering facepiece, provides a relatively low level of protection because it doesn’t seal as tightly as elastomeric or full-face respirators. Its APF is 10, meaning it reduces the contaminant concentration inside the mask to about one-tenth of the outside concentration, assuming proper use and fit. Higher protection devices—like full-face or powered respirators—have higher APFs, while very simple or loose-fitting devices have lower or different values. So, for a dust mask, the APF of 10 is the appropriate value.