Don’t Crack Under Pressure: Why Proper Drying Matters in Sterilization

In the fast-paced world of sterile processing everyone is looking for ways to speed things up. In the past, some technicians would crack open the sterilizer door after a cycle to hoping to achieve a faster and more thorough dry. While this may have been a common practice in the past, on a modern sterilizer doing this can increase the risk of contamination and wet packs.

The practice of opening the door slightly at the end of a sterilizer cycle originates from gravity sterilizers. These older units relied on the door being cracked open to circulate air in the chamber and promote evaporation. It is also important to note that the packs used at this time were made of a cotton muslin material that was more absorbent than the non-woven wraps used today. A modern sterilizer uses forced vacuum drying methods and does not require the door to be opened. 
Why don’t modern sterilizers require cracking the door?

Modern sterilizers (pre-vacuum and dynamic-air removal types) have built in systems that remove residual steam and moisture from the sterilizer chamber. This allows items to be dried in a controlled environment. The forced vacuum systems have eliminated the need for cracking open the door.

 

Cracking up the door can even cause problems in a modern sterilizer:

• Reduces the temperature difference between the sterile item and outside air – When an item is immediately removed from a sterilizer after a cycle is completed, there is a very high temperature difference between the item and outside air. This difference in temperature helps to push moisture from inside the pack towards the outside.
• Moisture present on the outside of a pack can wick microorganisms into the pack – Moisture present on a pack poses a contamination risk. AAMI recommends any packs with moisture present on the pack at the end of a cycle be rejected.
• Increase the risk of wet packs – Modern sterilizers are built to dry using forced vacuum methods. Packs left in the chamber after a cycle may cause humidity to condense inside of the pack instead of the outside.
  

 

Tips to help with drying:

• Remove the load immediately at the end of a cycle – Leaving items in the sterilizer can result in reintroduction of moisture as humidity condenses in the pack. Promptly removing a load reduces this risk and frees the sterilizer up sooner.
• Move the load to a cooldown area and allow it to cool down for at least an hour, sometimes more, depending on a variables like weight, packaging type etc. This allows items to reach room temperature gradually and promotes humidity to leave the pack rather than stay trapped inside.
• Do not touch a pack before it has been cooled down – handling packs before they are fully cooled can compromise sterility.
• Do not place hot items on a shelf for storage – Placing hot items on a cool storage shelf can cause condensation resulting in moisture buildup in packs.