Table D-ANSI Z88 Committee's 1991 Assigned Protection Factors for Particulate- Filter Respirators in ANSI Z88.2-1991 Submitted to ANSI for Approval on March 6, 1991.
| Type of Respirator | Respiratory Inlet Covering | |||
| Half MaskA | Full Facepiece | |||
| Example | Example | Example | Example | Example |
| Example | Example | Example | Example | Example |
| Example | Example | Example | Example | Example |
| Example | Example | Example | Example | Example |
A Includes 1/4 mask, disposable half masks, and half masks with elastomeric facepieces.
B Protection factors listed are for high efficiency filters and sorbents (cartridges and canisters). With dust filters an assigned protection factor of 100 is to be used due to the limitations of the filter.
C Although positive pressure respirators are currently regarded as providing the highest level of respiratory protection, a limited number of recent simulated workplace studies concluded that all users may not achieve protection factors of 10,000. Based on this limited data, a definitive assigned protection factor could not be listed for positive pressure SCBA's. For emergency planning purposes where hazardous concentrations can be estimated, an assigned protection factor of no higher than 10,000 should be used.
D Where the particle size is unknown or less than 2 µm (MMAD), a high efficiency filter shall be used. If the contaminant is a fume, use a filter approved for fumes or a high efficiency filter. If the contaminant size is known to be greater than 2 μm (MMAD), any filter type (dust, fumes, mist or high efficiency) may be used.
