Figure 8-8.Self-contained oxygen-brreathing apparatus with
harness straps should be snug, not too tight. Although
other types of facepieces may have fewer head harness
straps or may have various sizes and shapes of lenses,
most facepieces are similar in design. Because of this
close similarity, the methods of application can be
adapted to the one described and shown by figures 8-9,
8-10, and 8-11.
The six steps for donning the facepiece are as
1. Loosen the head harness strap so that the tab end
of each strap is against the facepiece buckle.
With both hands, fold these straps in a bundle
across the top of the facepiece. Hold the
facepiece and straps by grasping the upper sides
with both hands (fig. 8-10).
Place the chin well into the small pocket at the
bottom of the facepiece and fit the facepiece to
the temples and forehead.
Release the facepiece with both hands, but hold
secure to the harness and pull the harness over
the top of the head.
Tighten the chin straps first by pulling out and
back on the tabs provided. This operation
secures the facepiece in position and places the
head harness on the back of the head so that the
bottom strap is across the back of the neck and
below the ears.
Tighten the temple straps next and secure the
facepiece snugly to the head.
Tighten the top straps last, as shown in figure
Notice that the head harness is placed at the back of
the head, not on top. If the top straps are tightened first,
the head harness may be pulled out of position. The
facepiece is now ready to be tested for leakage. Hold
one hand over the end of the breathing tube, or squeeze
the breathing tube, and then try to inhale. If the
facepiece fits snugly, it should collapse against the
Donning the Side Shoulder
The harness of the side shoulder strap model must be
prepared before the equipment is lifted from the floor.
The only place necessary to grasp the harness or
equipment is where the takeup strap and shoulder strap
are buckled together. The takeup strap should be
arranged without twist, although the wide shoulder strap
may appear to have a half twist. This twist is normal for
proper fitting to the back and shoulder. The steps for
donning the side shoulder strap model (fig. 8-10) are as
1. Fold the loop end of the harness takeup strap
over upon itself and grasp the takeup strap with
the right hand, at this point, with the palm down.
2. Lift the equipment up along the left side of the
body by raising the right hand and arm toward
the head. At the same time, run the left arm
through the loop formed by the harness and