What is the general protection factor for a half-face respirator?

What is the general protection factor for a half-face respirator?

• A. 10
• B. 5
• C. 20
• D. 50

Answer: (A)

The general protection factor measures how much a respirator reduces exposure to a contaminant. For a half-face respirator, the standard figure is 10, meaning the air inside the mask is about one-tenth the concentration of the air outside, assuming a proper seal and correct use. So if the surrounding air has 1000 units of contaminant, the inside of the mask would be about 100 units under ideal conditions. The other numbers would correspond to different respirator types or fit levels, not the typical protection level for a half-face device. The key idea is that half-face units provide a tenfold reduction when worn correctly.

The general protection factor measures how much a respirator reduces exposure to a contaminant. For a half-face respirator, the standard figure is 10, meaning the air inside the mask is about one-tenth the concentration of the air outside, assuming a proper seal and correct use. So if the surrounding air has 1000 units of contaminant, the inside of the mask would be about 100 units under ideal conditions. The other numbers would correspond to different respirator types or fit levels, not the typical protection level for a half-face device. The key idea is that half-face units provide a tenfold reduction when worn correctly.