TABLE 1







CSA STANDARD Z94.4-93/ASSIGNED PROTECTION FACTORS



Type of Respirator                              Type of Facepiece
                                   Quarter          Half          Full

Air-purifying                            5            10            100

Atmosphere-supplying SCBA (demand)       -            10            100

Airline (demand)                         -            10            100


                                         Respiratory Inlet Covering

                                  Half        Full        Helmet     Loose Fitting
                                  Mask       Face        Hood       Facepiece

Powered air-purifying (HEPA)           50        1000        1000          25

Powered air-purifying (DMF)            --          100         100          --

Atmosphere-supplying
Airline-pressure demand                50        1000          ­­          --

Continuous flow                      50        1000        1000          25

SCBA (positive-pressure or
      open/closed circuit)              --      (< 1000)         --           --



NOTES:
1. APF are not applicable for escape-type respirators.

2. Combination respirators such as airline respirators equipped with an air-purifying filter should have the APF assigned on the basis of the mode of operation. For example, if the combination respirator is to be used on both the airline mode as well as the air-purifying mode, then the APF applicable to that respirator in the air-purifying mode applies.

3. The maximum concentration against which an air-purifying respirator will protect is determined by the design efficiency and capacity of the cartridge, canister, or filter and the facepiece-to-face seal on the user. For gases and vapours, the maximum concentration for which the air-purifying respirator is designed to be used in the appropriate assigned protection factor multiplied by the exposure limit (EL). However, air-purifying respirators are not to be used for entry into concentrations of contaminants which are at or above IDLH.

4. The above APF values are similar to values proposed in a new edition of ANSI Standard Z88.2 currently in preparation.



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