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one of the following methods: minimum fit factor of 500 is obtained.
(A) Average peak penetration method means (10) Filters used for quantitative fit testing
the method of determining test agent penetra- shall be replaced whenever increased breath-
tion into the respirator utilizing a strip chart ing resistance is encountered, or when the test
recorder, integrator, or computer. The agent agent has altered the integrity of the filter me-
penetration is determined by an average of the dia.
peak heights on the graph or by computer inte-
gration, for each exercise except the grimace 3. Ambient aerosol condensation nuclei counter
exercise. Integrators or computers that calcu- (CNC) quantitative fit testing protocol.
late the actual test agent penetration into the
respirator for each exercise will also be consid- The ambient aerosol condensation nuclei
ered to meet the requirements of the average counter (CNC) quantitative fit testing
peak penetration method. (Portacount™ ) protocol quantitatively fit tests
respirators with the use of a probe. The probed
(B) Maximum peak penetration method means respirator is only used for quantitative fit tests.
the method of determining test agent penetra- A probed respirator has a special sampling de-
tion in the respirator as determined by strip vice, installed on the respirator, that allows the
chart recordings of the test. The highest peak probe to sample the air from inside the mask.
penetration for a given exercise is taken to be A probed respirator is required for each make,
representative of average penetration into the style, model, and size that the employer uses
respirator for that exercise. and can be obtained from the respirator manu-
facturer or distributor. The CNC instrument
(C) Integration by calculation of the area under manufacturer, TSI Inc., also provides probe at-
the individual peak for each exercise except the tachments (TSI sampling adapters) that permit
grimace exercise. This includes computerized fit testing in an employee’s own respirator. A
integration. minimum fit factor pass level of at least 100 is
necessary for a half-mask respirator and a
(D) The calculation of the overall fit factor us- minimum fit factor pass level of at least 500 is
ing individual exercise fit factors involves first required for a full facepiece negative pressure
converting the exercise fit factors to penetration respirator. The entire screening and testing
values, determining the average, and then con- procedure shall be explained to the test subject
verting that result back to a fit factor. This pro- prior to the conduct of the screening test.
cedure is described in the following equation:
(a) Portacount Fit Test Requirements.
Overall Fit Factor =
(1) Check the respirator to make sure the sam-
_ Number of exercises _ pling probe and line are properly attached to the
1/ff + 1/ff + 1/ff + 1ff/ + 1/ff + 1/ff + 1/ff + 1/ff 8 facepiece and that the respirator is fitted with a
5
4
7
6
1
2
3
particulate filter capable of preventing significant
Where ff1, ff2, ff3, etc. are the fit factors for ex- penetration by the ambient particles used for the
ercises 1, 2, 3, etc. fit test (e.g., NIOSH 42 CFR 84 series 100, series
99, or series 95 particulate filter) per
manufacturer’s instruction.
(9) The test subject shall not be permitted to
wear a half mask or quarter facepiece respira- (2) Instruct the person to be tested to don the res-
tor unless a minimum fit factor of 100 is ob- pirator for five minutes before the fit test starts.
tained, or a full facepiece respirator unless a This purges the ambient particles trapped inside
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