OHST Practice Exam

Based on a qualitative fit test, what is the protection factor afforded by a half-mask face piece respirator?

1. 1

2. 10

3. 100

4. 1000

The correct answer is: 10

The protection factor afforded by a half-mask facepiece respirator, based on a qualitative fit test, is 10. This means that when a properly fitted half-mask respirator is used, it can provide a level of protection by filtering out airborne contaminants in the environment, allowing the wearer to breathe cleaner air at a ratio where the ambient concentration is up to 10 times higher than what is deemed safe. Qualitative fit testing assesses how well the respirator fits the individual by exposing them to a test substance (often a harmless aerosol or vapor) and observing if they can detect it while wearing the mask. If the individual does not detect the substance, it indicates that there is a sufficient seal, meaning the respirator can provide a minimum of this tenfold protection. In contrast, full-face respirators or powered air-purifying respirators offer much greater protection factors. Therefore, while half-mask respirators provide a beneficial level of protection, the 10-fold factor reflects the limitations inherent in their design compared to other types of respiratory protection.