Reference

Color Change Conditions

70 ℃    1 mol/L   FORM  15mins

FAILURES

PROCESSED AND 

SATISFACTORY

• The LISTER LCF41 Type 1 Chemical Indicator has an indicator ink bar printed on 

a white plastic strip. The chemical indicator stripes turn from red to green after exposure 

to formaldehyde sterilization process, offering immediate visual results. 

• The chemical indicator strip is an easy-to-handle internal pack monitor for formaldehyde 

sterilizer cycles.

      How the LCF41 LISTER MULTIVARIABLE 

     CHEMICAL INDICATOR works? 

When the formaldehyde sterilization process reaches the specified conditions of 5 to 15 

minutes, 70°C, and a formaldehyde concentration of 1 mol/L, the bordeaux-red ink on the 

multi-variable chemical indicator will change to green(or lighter green), quickly indicating 

whether the sterilization conditions have been met. 

To use, place the indicator card in each package, bag, or tray awaiting sterilization. After the 

sterilization process is complete, analyze the results based on the color change. If the ink 

on the multi-variable chemical indicator card turns to the reference color, it proves that the 

required conditions for sterilization have been satisfied.

If any of these critical variables do not meet the requirements specified by the standard, the 

indicator will not show a passing result. This means that the sterilization cycle may not have 

achieved the expected sterilization effect and the material cannot be considered sterile, and 

the sterilization cycle may need to be repeated.

The main failure causes are: 

» Inadequate cycle duration

» Improper cycle selection 

» Overloading/incorrect loading of the sterilizer

» Sterilizer malfunction

» Blocking indicator with large metal mass