The correct storage of processed instruments is important to protect them from environmental contamination. The major source of environmental contamination is airborne bacteria and viruses that settle on instruments and equipment. Critical instruments that must be sterile at the time of use must be stored bagged/wrapped until use. However, an efficient way to protect all sterilization critical instruments from environmental contamination is to bag them prior to sterilization and store them in the unopened bag/wrap. Critical instruments/items must be stored in a way that maintains the integrity of packs and prevents contamination from any source. Items required to remain sterile must not be stored in ultraviolet cabinets or disinfectants as these processes will compromise sterility. It is important that wrapped critical instruments are stored in a clean dry area and are subjected to minimal handling before use.

During storage, packs can be contaminated by:

• over-handling – this can happen through excessive transferring from one place to another or during rotation of instrument packs from over-stocking storage areas or from bundling packs together using rubber bands;
• moisture – if the pack is placed on a wet bench top, splashed with water, other liquids or aerosols; or
• penetration – if instruments break through the surface of the pack.

A package is considered to be nonsterile when it:

• is damaged or open;
• comes out of the steam sterilizer wet or is placed on a wet surface; or
• is dropped or placed on a dirty surface.

Storage areas must be dedicated for that purpose only and be free of dust, insects, and vermin. For open shelving, all items must be stored above floor level by at least 250 mm, from ceiling fixtures by at least 400 mm, and protected from direct sunlight. This will facilitate environmental cleaning and allow unrestricted airflow and prevent heating and degradation of the packaging material.

Quality Assurance

To ensure sterility of medical devices, mechanical and chemical biological indicators are required to evaluate the effectiveness of sterilization.