What is an APF according to the US OSHA respiratory protection standard 29 CFR 1910.134?
A. An APF is the number given as the result of a quantitative fit test when the wearer tests a specific respirator.
B. An APF is the level of protection a respirator or class of respirators is expected to offer to a trained user, as part of an effective respiratory protection program.
C. An APF is the level of protection a respirator or class of respirators is expected to offer to a new, untrained user.
D. An APF is the highest level of hazard where a respirator user can safely use a specific respirator.