United States Nuclear Regulatory Commission - Protecting People and the Environment

U.S. Nuclear Regulatory Commission

Acceptability of New Technology Respirator Fit Testing Devices

HPPOS-175 PDR-9111210266

Title: Acceptability of New Technology Respirator Fit

Testing Devices

See the memorandum from R. L. Pedersen to M. M. Shanbaky

(and others) dated April 10, 1989. The memo states that

new technology devices can be used to conduct quantitative

fit testing of respirators provided the device can be shown

to be technically adequate, satisfies regulatory

commitments, and meets the intent of the regulatory


The Radiation Protection Branch was queried on the

acceptability of new respirator fit testing devices that

were on the market. When determining that a method is

technically adequate, an inspector should keep in mind that:

1. Fit Factors determined by any quantitative fit test

are not Protection Factors and can not be used as such.

2. Acceptance criteria for Fit Factors should be set

at least ten times the Protection Factor of the mask being

fit (i.e., to show a proper fit on a mask with a protection

factor of 50, a Fit Factor of at least 500 should be


3. Testing methods should reasonably simulate use


4. An adequate base for correlating the parameter

being measured (aerosol concentration, pressure drop, etc.)

to a Fit Factor, should be established.

It has been reported that one device on the market,

QUANTAFIT, requires the subject to be absolutely still with

no facial movement. Apparently momentary breaks in the

face seal, caused by facial movement, fail the test. This

type of leakage is well known even in a good fitting

respirator and it is a major contributor to the overall

leakage (or fit) of the mask. If this information is

correct, it is difficult to see how this method can

adequately measure the respirator fit.

Regulatory references: 10 CFR 20.103, 10 CFR 20.1703

Subject codes: 5.6, 8.10

Applicability: All

Page Last Reviewed/Updated Thursday, March 29, 2012