Page 118 - L:\GROUP\SDT\zip_disk\Book2.PDF
P. 118
feedback in the form of a real-time pressure (7) The QNFT protocol shall be followed ac-
trace of the in-mask pressure is provided and cording to section I. C. 1. of this appendix with
used to determine test validity and quality. A an exception for the CNP test exercises.
minimum fit factor pass level of 100 is neces-
sary for a half-mask respirator and a mini- (b) CNP Test Exercises.
mum fit factor of at least 500 is required for a
full facepiece respirator. The entire screening (1) Normal breathing. In a normal standing
and testing procedure shall be explained to the position, without talking, the subject shall
test subject prior to the conduct of the screening breathe normally for 1 minute. After the nor-
test. mal breathing exercise, the subject needs to
hold head straight ahead and hold his or her
(a) CNP Fit Test Requirements. breath for 10 seconds during the test measure-
ment.
(1) The instrument shall have a non-adjustable
test pressure of 15.0 mm water pressure. (2) Deep breathing. In a normal standing posi-
tion, the subject shall breathe slowly and
(2) The CNP system defaults selected for test deeply for 1 minute, being careful not to hy-
pressure shall be set at — 15 mm of water (- perventilate. After the deep breathing exercise,
0.58 inches of water) and the modeled inspira- the subject shall hold his or her head straight
tory flow rate shall be 53.8 liters per minute ahead and hold his or her breath for 10 sec-
for performing fit tests. onds during test measurement.
(Note: CNP systems have built-in capability to (3) Turning head side to side. Standing in
conduct fit testing that is specific to unique place, the subject shall slowly turn his or
work rate, mask, and gender situations that her head from side to side between the ex-
might apply in a specific workplace. Use of treme positions on each side for 1 minute.
system default values, which were selected to The head shall be held at each extreme mo-
represent respirator wear with medium car- mentarily so the subject can inhale at each
tridge resistance at a low-moderate work rate, side. After the turning head side to side ex-
will allow inter- test comparison of the respira- ercise, the subject needs to hold head full
tor fit.) left and hold his or her breath for 10 sec-
onds during test measurement. Next, the
(3) The individual who conducts the CNP fit subject needs to hold head full right and
testing shall be thoroughly trained to perform hold his or her breath for 10 seconds during
the test. test measurement.
(4) The respirator filter or cartridge needs to be (4) Moving head up and down. Standing in
replaced with the CNP test manifold. The inha- place, the subject shall slowly move his or
lation valve downstream from the manifold ei- her head up and down for 1 minute. The
ther needs to be temporarily removed or subject shall be instructed to inhale in the
propped open. up position (i.e., when looking toward the
ceiling). After the moving head up and
(5) The test subject shall be trained to hold his down exercise, the subject shall hold his or
or her breath for at least 20 seconds. her head full up and hold his or her breath
for 10 seconds during test measurement.
(6) The test subject shall don the test respirator Next, the subject shall hold his or her head
without any assistance from the individual full down and hold his or her breath for 10
who conducts the CNP fit test. seconds during test measurement.
110
