What is a Critical, Semi-critical and Non-critical instrumen
In 1939 Earle Spaulding published a paper on disinfection of surgical instruments in a chemical solution and proposed a strategy for sterilization or disinfection of inanimate objects and surfaces based on the degree of risk involved in their use for the medical community.
Due to his extensive study of disinfection and sterilization of medical instruments, Spaulding further refined his classification of appropriate treatment of medical devices based upon how a device is used. Chemical disinfection was classified as low level, high level, and sterilization based upon whether a device contacted intact skin, mucous membranes or was introduced into the sterile cavity of the body.
Below is an extract from the AS/NZS: 4187
Level of Risk |
Process |
Storage |
Critical A medical device that comes into contact with the vascular system or sterile tissue and that shall be sterile at the time of use |
Clean as soon as possible after using
Sterilise by moist heat after cleaning
If RMD is heat or moisture sensitive, sterilise suing an alternative process, e.g. automated low temperature chemical sterilising process, liquid chemical sterilising process, or ethylene oxide sterilising process |
Sterility shall be maintained
Packaged RMDs shall be stored to prevent environmental contamination in a designated storage area to protect RMD
RMDs processed through a liquid chemical sterilising process shall be used immediately |
Semi‐critical A medical device that comes into contact with mucous membranes or non‐intact skin |
Clean as soon as possible after using Sterilise by moist heat after cleaning If RMD will not tolerate moist heat sterilisation use a low temperature sterilisation process or thermal disinfection or disinfection using a high level instrument grade chemical disinfectant |
Store to prevent environmental contamination in a designated storage area to protect RMD |
Non‐critical A medical device that only comes into contact with intact skin but not mucous membranes |
Clean as necessary with detergent solution If further treatment is necessary, disinfect with compatible low level or intermediate level instrument grade disinfectant after cleaning |
RMDs shall be stored in a clean dry place to minimise environmental contamination |
To get a copy of the standards go to the standards site and search 4815 or 4187 to find the relevant standards for your practice