IMPORTANT STERILIZATION FACTS
Steam is an ideal sterilizing agent since
it kills microbes quickly, and steam has
the additional important property of self-
caused forced penetration. A large
volume of steam condenses to a very
small volume of water and more steam is
drawn in to replace it. This causes
excellent penetration of fabrics and some
papers and plastic films. Hot air or
sterilizing gases do not approach steam
in their ability to penetrate.
The greatest cause of sterilization failure
is the trapping of air in the material being
sterilized so that it cannot escape. When
this happens, the air forms a cool air
pocket which has a lower temperature
than the surrounding steam. It can also
form an air-steam mixture which has a
lower temperature than the pure steam.
The most frequent causes for this failure
are dressing packs wrapped too tightly,
made too large, failure to turn basins and
other metal or glass containers onto their
sides, and failure to properly follow the
directions as to current sterilizer
operation and maintenance. (Refer to
Item 5, page 3, regarding "exhausting" to
remove trapped air.)
It is essential that all sterilizers be
regularly checked for proper steam
penetration to the center of the load.
Since the first sign of sterilization failure
is a drop in the temperature at the center
of the dressing pack or sterilizer load, it
is recommended that a temperature
measuring device be used at the center
of each pack or load of instruments.
Indicating tape or strips are no substitute
for the self-contained types as..."melt
indicator inside a small glass vial," as
temperature accuracy is essential. The
pressure gauge on the sterilizer indicates
the approximate temperature at the
exhaust line, not at the center of the
packs. The gauge cannot indicate the
presence of trapped air, therefore, center-
of-pack controls or vials are recom-
mended. Different types and brands of
sterilization indicators are available from
your hospital supply or scientific supply
dealer.
7
PRESSURE GAUGE ACCURACY: The
gauges are rated as having an accuracy
of 3%-2%-3%. This designates plus or
minus 3% of the full span for the first
and last quarter of the dial, and 2% for
the middle 50% of the dial.
More specifically, this gauge rating
conforms to the pressure gauge standard
ANSI B40-1-1980. This standard is
entitled "Gauges-Pressure, Indicating
Dial Type-Elastic Element," and covers
every aspect of pressure gauge
manufacture and use. The gauge is
considered "Accuracy Grade B" in accor-
dance with this specification.
SOLUTIONS/SUGGESTIONS FOR
WET BAGS OR PACKS IN
STERILIZER:
1. Place absorbent towels between layers
and on top of items being sterilized.
2. Use sterile gloves to remove the sterile
bags or packs from container.
3. Use sterile tongs to remove sterile
bags or packs from container.