It is critical that infection preventionists understand the principles and practices related to sterility assurance so that they may 
assist their institutions' sterile processing managers in ensuring that medical instruments and devices are properly 
reprocessed and do not contribute to the transmission of disease-causing pathogens. This report summarizes the essentials 
of sterility assurance for the infection prevention. 

The delivery of sterile products for use in patient care depends not only on the effectiveness of the sterilization process but also 
on the unit design, decontamination, disassembling and packaging of the device, loading the sterilizer, monitoring, 
sterilant quality and quantity, and the appropriateness of the cycle for the load contents, and other aspects of device 
reprocessing. 
The aim of central processing is the orderly processing of medical and surgical instruments to protect patients from infections 
while minimizing risks to  staff and preserving the value of the items being reprocessed. As the CDC (2008) explains, 
"Ensuring consistency of sterilization practices requires a comprehensive program that ensures operator competence 
and proper methods of cleaning and wrapping instruments, loading the sterilizer, operating the sterilizer, and monitoring 
of the entire process. Furthermore, care must be consistent from an infection prevention standpoint in all patient-care settings, 
 such as hospital and outpatient facilities." 

The concept of what constitutes "sterile" is measured as a probability of sterility for each item to be sterilized. 
At present, a sterility assurance level(SAL) of 10-6 is generally accepted for sterilization procedures, i.e. a probability of not more than one viable microorganism in an amount of  1 million sterilized items of final product. 

Current guidelines may require longer exposure times and.or the uyse of single wrappers or containers designed to allow for aseptic transfer of an item to the point of use. 
Documentation ensures that the sterilization process is monitored as it is occuring, ensures that cycle parameters have been met, and established accountability. 
Sterilization process monitoring devices include physical monitors, called biological indicators(BIs) and chemical indicator(CIs). 
According to the CDC(2008), " Biological and chemical indicator testing is also done for ongoing quality assuring testing of representative samples of actual products being sterilized and product testing when major changes are made in packing , wraps, or load configuration.