Reference

Color Change Conditions

60 ℃  1 mol/L 

FORM 50mins

FAILURES

PROCESSED AND 

SATISFACTORY

• The LISTER LCF40 Type 4 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 LCF40 LISTER MULTIVARIABLE 

 CHEMICAL INDICATOR works

When the formaldehyde sterilization process reaches the specified conditions of 50 minutes, 

60°C, and a formaldehyde concentration of 1 mol/L, the bordeaux-red ink on the multi-variable 

chemical indicator will change to 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