An autoclave is a self locking machine that sterilizes with steam under pressure.
Sterilization is achieved by the high temperature that steam under pressure can reach.
The high pressure also ensures saturation of wrapped surgical packs. Flashing' is often used when a critical instrument is dropped. Indicators should be on the inside and outside of equipment pack. Expiration dates should be printed on all equipment packs. Color indicators are also included on the outside and inside of equipment sterilized in paper packages.