3M 1492V - Interpretation of Results; Explanation of Symbols

9. Each day that a processed 1492VBI is incubated, activate and incubate at least
one non-processed 1492VBI to use as a positive control. Follow the activation
instructions provided in Step 8 above. Write a "C" (for "control") and the date
on the BI label. The positive control should be from the same lot code as the
processed biological indicator. The positive control BI helpsconfirm:
• correct incubation temperatures aremet,
• viability of spores has not been altered due to improper storage temperature,
humidity or proximity tochemicals,
• capability of media to promote rapid growth,and
• proper functioning of the 490Auto-reader.
10. Incubation andReading:
Incubate the positive control and steam processed 1492VBIs at 56 ± 2°C in
a 490 Auto-reader. See the 490 Auto-reader Operator's Manual for the proper
use of this equipment. Positive results are available within 1 hour. The 490
Auto-reader will indicate a positive result as soon as it is obtained. The final
negative 1492VBI reading is made at 1 hour. After the results are displayed and
recorded, the 1492VBIs may bediscarded.
Interpretation ofResults
FluorescentResults
The positive control (unprocessed) 1492VBI must provide a positive fluorescent
result (+ on the 490 Auto-reader LCD display). Processed 1492VBI results are
not valid until the positive control reads fluorescent positive. The positive control
should read positive (+ on the LCD display) at or before 1hour. If the positive
control reads negative (- on the LCD display) at 1 hour, check the 490 Auto-reader
Operator’s Manual Troubleshooting Guide. Retest the 490 Auto-reader with a new
positivecontrol.
With processed 1492VBIs, a positive (+ on the LCD display) result indicates a
sterilization process failure. A final negative processed 1492VBI reading (- on the
LCD display) after 1hour of incubation indicates an acceptable sterilizationprocess.
Act immediately on any positive results for processed BIs. Determine the cause of
the positive BI following facility policies and procedures. Always retest the sterilizer
and do not use sterilizer for processing loads until three consecutive BI results
arenegative.
Optional Visual pH Color ChangeResult
The 1492VBI is normally discarded after the fluorescent result has been recorded. If,
however, special studies are desired, 1492V BIs may be further incubated for a visual
pH color change result. After activation and during incubation, the white Nonwoven
Material will absorb the bromocresol purple indicator, the pH-sensitive indicator dye
in the growth media, and appear blue. In the case of the positive control BI a yellow
color change of the growth media and/or Nonwoven Material will appear within 48
hours. Any observation of a yellow color within the vial indicates a positiveresult.
In the case of a processed 1492VBI, a media and/or Nonwoven Material color
change from purple to yellow indicates a sterilization process failure. A negative pH
color change result, i.e., media and Nonwoven Material remain purple/blue, can be
assessed at 48hours.
Storage
• Best stored in original box under normal room conditions: 59-86ºF (15-30ºC),
35-60% relative humidity (RH).
• Do not store 1492VBIs near sterilants or otherchemicals.
Disposal
Dispose of used 1492VBIs according to your health care facility policy.You may wish
to steam sterilize any positive biological indicators at 132°C (270°F) for 4minutes
or at 275°F (135°C) for 3minutes in a dynamic-air-removal steam sterilizer prior
todisposal.
Explanation of Symbols
Catalogue Number
Caution, see instructions for use
Do not reuse
Use by date
Batch code
Manufacturer
Date of manufacture
Product is designed for use with steam sterilizationcycles.
British Standards Institution (BSI) Kitemark™ License for compliance with
BS EN ISO 11138-1:2006 and BS EN ISO 11138-3:2009