ISO 17665
Steam Sterilization for Medical Devices

ISO 17665
Steam Sterilization for Medical Devices

Steam Sterilization is a simple yet very effective decontamination method. Sterilization is achieved by exposing products to saturated steam at high temperatures (121°C to 134°C). Product(s) are placed in a device called the autoclave and heated through pressurized steam to kill all microorganisms including spores. The device's exposure time to steam would be anywhere between 3 to 15 minutes, depending on the generated heat.

Steam sterilization process is not appropriate for many materials due to the high temperatures involved. Some quarantine/down time is required once products have been sterilized. Sterilized packages need to be allowed to dry before being removed from the autoclave to prevent contamination. Once removed, they must be allowed to cool to ambient temperatures, which may take several hours.

For effective sterilization it is critical that the steam covers all surfaces of the device. To ensure optimal conditions, many autoclaves have built in meters that display temperature and pressure conditions with respect to time. Biological indicator devices and Indicator tape which changes color are also used to gauge the performance of the autoclave. The chemical tape is placed both inside and outside the sterilized packages, whereas bioindicator devices release spores inside the autoclave. The spores are incubated for 24 hours at the end of which time their growth rate is measured. If the spores have been destroyed it indicates that the sterilization process was effective.

ISO 17665:

ISO 17665 specifies requirements for the development, validation and routine control of a moist heat sterilization process for medical devices. Moist heat sterilization processes covered by ISO 17665-1:2006 include but are not limited to:

  • Saturated steam venting systems
  • Saturated steam active air removal systems
  • Air steam mixtures
  • Water spray
  • Water immersion

ISO 17665 covers sterilization of solid as well as liquid medical devices. According to the standard it is the manufacturer's responsibility to develop the process and provide guidelines/ instructions for operation and validation of the process. The standard also requires detailed documentation of all conditions that affect the process performance now and in the future. ISO 17665-1 only provides very general guidelines on steam sterilization requirements and operations. ISO 17665-2 tries to describe these guidelines more specifically through the use of examples and further explanation.


LSO provides Contract Steam Sterilization services for any product capable of withstanding high-temperature sterilization. Our sterilizer features a high capacity 19 cubic foot chamber size. We can program any desired cycle parameters and duplicate an existing sterilization cycle or develop a cycle for specialized requirements.

Sterilization validations are performed according to ANSI/AAMI/ISO guidelines. Our staff will prepare the protocol, perform all required sterilization cycles, conduct all testing and generate a complete final report. Customers review and approve the protocol before the validation process begins.