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Understanding Wet Pack & Wet Load Investigations

What is a wet pack?

So, what does it mean to have a wet pack in your sterile processing department? Wet packs result from a variety of things that take place during or after the steam sterilization process. A wet pack can be defined as identifying visible moisture on the inside or outside of the item or package after it’s been exposed to a steam sterilization process. A wet load can be defined as multiple wet items stemming from one autoclaved load. Here at Belimed, Inc. we also know that wet loads can cause surgical procedure delays that could impact the patient, frustrating team members and ultimately undesired outcomes. We want to help you through the troubleshooting steps and investigation methods that can be used to identify the source and cause of a wet pack issue.

A Multi-variable obstacle 

The most important variable in having a successful outcome during the assessment of moisture is understanding how to approach the issue. Because there are so many factors to consider it is critical to have a dedicated and educated investigating team. Some things to look for during the investigation are; 


  • Equipment functionality
  • Utilities supporting the equipment and department, especially the steam source
  • Sterilizer load capacity and loading practices
  • Environmental controls such as department temperature and humidity settings
  • Differences in the sterilization operational workflow


Communication and collaboration can make or break your success when trying to solve this heightened and often stressful situation. Those involved in this investigation process must understand how to look at all aspects of the problem, and be open minded. It is possible that the issue is due to a recurring cause, but it could be created by an entirely different source each and every time.


Creating an Activation Team


The investigation process requires a variety of members to be present at the collaboration table, working as a cohesive team and speaking the same language. Here are examples of those who could be involved;


  • SPD Representative – drives and manages the investigation process, handles documentation and communication among the activation team and hosts routine huddles to share information.
  • Infection Control Representative – manages and handles the patient record and necessary patient related communications, only necessary when and if a wet pack reaches a patient contact situation in a surgical procedure without resolution, or sterility is in question.
  • OR Personnel (Nursing, Scrub Techs, and Physicians) - focuses on proper documentation, helps streamline the investigation, helps educate the teams involved and keep their operating (OR) rooms calm during the process, makes sure suspected or confirmed wet pack items do not reach the patient, and quickly communicates when and if moisture is identified .
  • Quality & Education- focuses on reviewing the investigation, shares education and knowledge with the team, ensures the process is following proper protocol, uses every occurrence and investigation results as a training opportunity to avoid recurrences in the future.
  • Sterilization Equipment Representation- provides support during investigation, verifies the issue is not from the equipment source, such as steam lines, autoclave malfunctions or leaks, and checks all functions of the equipment to rule out equipment related
  • Biomedical Engineer- helps with the investigation as needed, organizes communication with the equipment manufacturer, handles internal management of maintenance history of the equipment, checks all internal causes or equipment failures.
  • Maintenance or Facilities Engineer- leads and completes the investigation into possible utility causes, water main lines, steam generators, steam piping, insulation and all utilities that are involved with the equipment in the SPD.


A Thorough Investigation

The objective of a wet pack investigation is to determine the source, or sources, of the moisture itself. While this can be challenging, the fewer variables that are altered during the process the better, and faster, a resolution can be identified. The investigation begins when the first sign of moisture is seen. A wet pack can be identified in in the sterile processing department or in the operating room. The dedicated team should be alerted through an “activation” method of communication. This will help streamline the investigation in a systemic way. Each dedicated representative listed above will complete their assigned responsibilities to help determine the root cause, or causes, of the wet pack issue. The investigation timeline can be different in each situation, and there isn’t a definitive agenda. Sometimes the solution can be identified immediately, while other times it could take much longer.


Steps to take when a wet pack is initially observed:


  • Identify the location of the moisture by verifying if it is inside of the package or on the outside of the packaging.
  • Activate your “investigation team”, and begin documentation preparations
  • If one wet pack is identified, the investigation will include proper steps in locating items from the same load to determine if further moisture is found in additional packs, this will provide input to determine the recall initiation
  • Communicate promptly, calmly and provide information to the activation team and SPD staff so troubleshooting can begin
  • Ensure all reprocessing professionals are allowing sets to cool properly, checking temperature of sets, post sterilization, before release, and confirming the environmental conditions of the sterilization load cooling area is within defined parameters


Documentation 101

Anytime there is an investigation in sterile processing it should be thoroughly documented and recorded. Records should be kept in a safe place for future reference if needed, and to help look for and then analyze any trends. Each occurrence should be well written and in a clear method that is easy to follow and understand. Effective collaboration between departments on the investigation team is critical. If sterile processing decides to use a logbook to document errors as they arise, it’s important to make sure all information is accurate. The operating room personnel should be providing useful information as quickly as possible, or when requested. If the incident resulted in a recall action, the recall documentation can help identify trends and pinpoint the root cause, or causes, of the wet pack.


Examples of Wet Pack Documentation:


  • Include digital photos of the processed load and the wet pack item(s)
  • Try to include the location of the moisture identified, pictures work well
  • If your department has a quality system in place or tracking system of some kind, it is important to enter the information into that system, especially if a recall takes place
  • Document the sterilizer cycle parameters, moisture location(s), weight of the wet pack set, packaging material used, and load cooling temperature & time
  • Ensure the documentation includes recall information if the whole load is recalled
  • Document the resolution once it is determined and include the steps that were taken to remedy the issue




ANSI/AAMI ST79: 2017 Comprehensive Guide to Steam Sterilization and Sterility Assurance in Healthcare Facilities. Annex O, pp. 166.

International Association of Healthcare Central Service Materiel Management (IAHCSMM), Central Service Technical Manual, Eighth Edition, 2016.

International Association of Healthcare Central Service Materiel Management (IAHCSMM), Central Service Leadership Manual, Third Edition, 2020.