Calculate the Maximum Use Concentration (MUC) for a PAPR with a PEL of 50 ug/m3.

To determine the Maximum Use Concentration (MUC) for a Powered Air-Purifying Respirator (PAPR), it is essential to know the relationship between the permissible exposure limit (PEL) and the assigned protection factor (APF) of the respirator. The MUC is calculated by multiplying the PEL by the APF.

In this case, the PEL is 50 micrograms per cubic meter (ug/m³). The APF for a PAPR is typically 10 or higher, depending on the specific equipment and conditions of use. Using an APF of 1,000 as a standard for many PAPRs, the calculation would be:

MUC = PEL × APF

MUC = 50 ug/m³ × 1,000

MUC = 50,000 ug/m³

Choosing 50,000 ug/m³ reflects this multiplication, which aligns with the guidelines existing in occupational health standards. This helps ensure that workers are protected from exposure levels beyond what is safe according to regulatory limits. The other options represent significantly higher concentrations, which do not adhere to the safe exposure limits established in industrial hygiene practices. Thus, the correct answer of 50,000 ug/m³ emphasizes the importance of