Asbestos Hazard Emergency Response Act (AHERA) Certification Practice Exam

What is the Protection Factor (PF) of a half-face respirator?

1. 5x

2. 10x

3. 20x

4. 50x

The correct answer is: 10x

The protection factor (PF) of a half-face respirator is typically 10. This means that the respirator can provide a level of protection that reduces the concentration of hazardous ambient air contaminants, such as asbestos, to one-tenth of the level outside the respirator. This factor is based on testing and establishes that when a half-face respirator is properly fitted and used, it can effectively filter out a significant portion of harmful particles, allowing the wearer to breathe cleaner air. The calculation considers the respirator's ability to maintain a seal against the face and its filtration efficiency. For example, if the ambient concentration of asbestos fibers is 100 fibers per cubic centimeter (f/cc), a half-face respirator with a PF of 10 would theoretically reduce the inhalation exposure to only 10 f/cc. This protective capability is essential in environments where asbestos fibers are present, ensuring that workers can safely perform their tasks with minimized risk of inhalation exposure. Other respiratory options may offer higher protection factors, but for a half-face respirator, the established PF is 10, reflecting its typical usage and effectiveness in situations involving airborne contaminants.