SUBJECT: OSHA ADDS A NEW QUANTITATIVE FIT-TESTING PROTOCOL
ORIGIN: Moldex Technical Services Department
DATE: November 2005
REVIEWED/UPDATED: August 2021
OSHA’s regulation on fit testing 1910.134 accepts the use of various types of quantitative fit tests. These include the use of the Portacount®, which is a Condensation Nuclei Counter (CNC) and utilizes either ambient aerosol or a generated aerosol of Sodium Chloride. The Portacount® manufactured by TSI, Inc., can be used to fit test elastomeric respirator facepieces as well as disposable respirators, when used in conjunction with the N95-Companion™, which includes the aerosol generator and other electronic components necessary to fit test N95 disposable respirators. The protocol requires that the test subject perform 8 exercises to complete the fit test.
Moldex has helpful videos on the 7000/7800/9000 Probed Cartridge webpage – https://www.moldex.com/product/7006-probed-cartridge-quantitative-fit-test/
OSHA also accepts the use of the Controlled Negative Pressure (CNP) system the “Fit Tester 3000”, which is manufactured by Occupational Health Dynamics (formerly Dynatech Nevada). This system can only be used for elastomeric facepieces and requires that the test subject hold their breath when the actual fit of the respirator is being measured. It also requires the 8 standard exercises, with some modifications including redonning of the respirator on exercise 8.
OSHA recently approved a new test protocol to be used with the CNP and CNC systems. OSHA allows that the original 8 exercise protocol be used, or that the new protocols be used. For CNP the protocol has only 3 exercises followed by two redonnings of the respirator and repeating the 3 exercises after each redonnings. For CNC the protocol has 4 exercises which must be done for 30 seconds each.
For details visit:
For additional information on quantitative fit testing, please contact the Moldex® Technical Services Department at (800) 421-0668, ext. 512/550. The CNP model number for the Moldex® test adapters is #9513-0188 – Kit #22 which is used for the 8000 Series half mask and the Kit#9513-0400 – Kit #40 may be used for the Moldex 7000, 7800 and 9000 Series.
Occupational Health Dynamics
WARNING: The information contained in this Tech Brief is dated and was accurate to the best of Moldex’s knowledge, on the date above. It is not meant to be comprehensive, nor is it intended to be used in place of the warning/use instructions that accompany Moldex respirators. Outside of the USA, check with all applicable and local government regulations.
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