Assigned Protection Factor (APF)
Definition - What does Assigned Protection Factor (APF) mean?
Assigned Protection Factor (APF) is the level of protection a respirator can be expected to provide if it is functioning properly and the user is wearing it correctly. APF is scored via a number, allowing users to gage how much contaminant they are expected to inhale while wearing the respirator.
Safeopedia explains Assigned Protection Factor (APF)
Various groups, such as the National Institute for Occupational Safety and Health (NIOSH), the Occupational Safety and Health Administration (OSHA) and the American National Standards Institute (ANSI) have proposed standards for different types of respirators. However, APF overrode all other standards previously used in 2006. APF sets guidelines to be used by employers and management in selecting proper personal protective equipment (respirators) for hazardous jobs (in air mixed with dusts, fibers, vapors, fumes and biological hazards). Under the related provisions, employers must provide suitable respirators to the employees. Employers must also ensure that these respirators comply with all other requirements under routine and assumed emergency situations. APFs provide employers with important information about matters to be considered while choosing respirators.
While measuring APF, air samples are taken simultaneously outside and inside the respirator as the worker continues the job. An of APF 10 indicates that a respirator reduces contaminant concentration by one-tenth.