Autoclave – Achieving Effective Sterilization

Failure to effectively sterilize an autoclave load can be due to either a mechanical problem with the equipment or operator error. Report mechanical problems immediately to your department or building point of contact. Operator errors are generally due to insufficient steam circulation and penetration due to:

  • Autoclaving for too short of a time for the size and configuration of load
  • Using an autoclave bag that is too large for the autoclave
  • Filling bags more than 3/4 full
  • Closing bags before autoclaving
  • Placing material in plastic container that does not allow efficient heat transfer
  • Placing material in plastic container with high sides that does not allow effective steam penetration

The following table describes some problems frequently encountered when using an autoclave and the appropriate corrections:

Causes and Corrections for Common Autoclave Problems

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Clogged Drain

Causes and Corrections for Clogged Drains
Cause Corrections
Agar boiled over or other debris Clean chamber drain strainer. If still clogged, call FM.

 

Wet Wrappers

Causes and Corrections for Wet Wrappers
Cause Corrections
Overloaded baskets or racks Load loosely.
Clogged chamber drain strainer not allowing water to drain Remove strainer; free openings of lint, sediment, etc.
Clogged chamber drain line Clean chamber drain line; mix 2 tbsp trisodium phosphate with one quart of hot water, pour into chamber drain line. Then flush drain with one quart of hot tap water. If still clogged, call FM.
Excessively large or dense packs Reduce pack to 12" x 12" x 20" or less; and 12 pounds or less.
Placing warm sterilized packs on cold surfaces Allow packs to cool on rack or in autoclave
Sterilized goods removed from sterilizer too soon following completion of cycle Allow goods to remain in autoclave additional 15 minutes with door slightly open.
Improper loading Place packs on edge; arrange packs to present the least possible resistance to passage of steam and air through layers of load.
Combining items in a pack Wrap separately.

Corroded Instruments

Causes and Corrections for Corroded Instruments
Causes Corrections
Poor cleaning; residual soil Improve cleaning. Do not allow soil to dry on instruments.
Moisture Check sterilizer for drying efficiency. Store in a dry area
Exposure to harsh chemicals; acid, iodine, sodium chloride, detergents, etc. Do not expose instruments to these chemicals. If exposure occurs, rinse thoroughly after contact.
Inferior instruments Use only top-quality instruments
Metallic deposition resulting from galvanic reaction with sterilizer components Keep sterilizer chamber and trays clean. Use detergent recommended by manufacturer

 

Liquid Container Caps "Blow Off"

Causes and Corrections for Liquid Container Caps that Blow Off
Cause Correction
Exhausting sterilizer too rapidly Use slow exhaust cycle.
Maladjusted slow exhausted valve Notify FM.

 

Loss of More than 5% Fluid Volume During Sterilization

Causes and Corrections for Loss of More than 5% Fluid Volume During Sterilization
Causes Corrections
Exhausting sterilizer too rapidly Use slow exhaust cycle.
Maladjusted slow exhausted valve Notify FM.

 

Cracked or Broken Glass Containers

Causes and Corrections for Cracked or Broken Glass Containers
Causes Corrections
Cracked before sterilization; poor inspection following cleaning Inspect thoroughly after cleaning; discard chipped or cracked flasks.
Containers not heat-resistant or with screw-caps Use only borosilicate (Type 1) containers and automatic sealing and venting closures.

 

Solutions Boiling when Door Is Open

Causes and Corrections for Solutions Boiling when Door Is Open
Causes Corrections
Door opened too quickly Do no open door until temperature gauge is below 212°F and pressure gauge is at "0". Do not touch or move a load of boiling solutions.
Maladjusted slow exhaust valve Notify FM.

 

Indicator Shows Sterilization Not Complete

Causes and Corrections for When Indicator Shows Sterilization Not Complete
Causes Corrections
Load may be too large, too dense, or improperly loaded in chamber Size of packs should not exceed 12' x 12' x 20'; weight should not exceed 12 pounds. Pack should rest on edge; all packs arranged to present the least possible resistance to passage of steam and air through layers of load.
Time not sufficient for load Increase time.
Sterilizer may be malfunctioning Notify FM.

 

Steam Leakage

Causes and Corrections for Steam Leakage
Causes Corrections
Worn gasket Call FM.
Door closed improperly Close properly. If problem continues, notify FM.

 

Chamber Door Will Not Open

Causes and Corrections for Chamber Door that Will Not Open
Causes Corrections
Vacuum in chamber Follow manufacturer's instructions.
Door-lock clutch is jammed Follow manufacturer's instructions.
Gasket sticking to door frame  Notify FM.