The Problem of Sterilization Indicator Tape Fading in Sterile Storage

In a previous blog we addressed issues surrounding the proper operation and maintenance of steam sterilizers, including the use of monitoring tools. These monitoring tools should include process challenge devices (PCDs), chemical indicators (CIs), biological indicators (BIs) and physical monitors. Personnel operating steam sterilizers must be consciously deciding whether or not to release each load based on the results of these various monitoring tools. In this blog we are going to focus on a recently identified problem with certain types of chemical indicators (CIs) that allow personnel to distinguish processed loads from unprocessed loads with a simple glance. The most common external CI is steam sterilization indicator tape that changes color if all of the sterilization cycle parameters were met at the end of a cycle. AAMI ST79 Section 13.5.2.2.1 recommends that all packages should have a Type 1 external CI unless the internal CI is visible. If the CI has not changed color after the sterilization cycle is complete, that load must not be used and you must investigate the cause of the failure. A problem with steam sterilization indicator tape has recently emerged. This problem was the topic of some recent discussions by AAMI members on the AAMI Member Discussion Group.  The discussion was initiated by this email: “Has anyone had any experience with sterilization tape and/or locks fading in sterile storage? The facility asking has taken some steps to negate the issue but is still seeing some changes. They have moved the low temperature trays away from the steam trays to the best of their ability but still in the same room due to space constraints. They have reviewed their EVS products and have checked the temp and humidity in the room, all are within acceptable ranges. They have also tried different tape manufactures. Their next step is to look at lighting; however, I have not been able to find any literature on what type of lighting should be utilized in sterile storage to help support their efforts to have the lighting changed. If anyone knows of any documents or can offer suggestions on the issue, it would be greatly appreciated! Thank you.” CSR Educator and Quality Control, __________ Hospital1 The post elicited this email who pointed out that: “We occasionally get a bad batch of tape and it fades in sterile storage after a short period of time. When that happens we are just reprocessing to be on the safe side. I have not been able to pinpoint what it causing it. And the manufacturer denies any problem with the product.”  Sterile Processing Supervisor, Perioperative Services, ___________ Hospital2   These comments were quickly followed up by this email that said “We are seeing the same issue with the _____ brand of tape.  We just switched to ______ tape and are trialing it to see if it too fades during sterile storage.” Sterile Processing Manager, ___________ Medical Center3 A possible solution to the problem was offered which suggested that “I have seen a lot of this lately. One possible solution is to limit the UV in the room from fluorescent lighting. There are UV shields available on Amazon and from others. Be sure to choose the ones that claim to shield UV. Not just those that protect from a broken bulb.” Quality Processing Resource Group LLC, Glen Allen VA4 Another potential cause of the problem was suggested, “This has been happening ever since they had to take the lead out of tape. Going "lead-free" wasn't an option so they can't go back. They just haven't figured out a way to make the color stay. It all fades no matter what company you get it from because the lead was why it kept its color.” Central Sterile Supervisor, ________Hospital5 Taking the lead out of the tape as the potential cause of the problem was also suggested that “I have found that the lead-free tape slowly fades no matter the vendor or conditions. We switched back and forth. I think it started ever since they redesigned the tape to remove all the lead. In the beginning after the switch to lead-free tape we had to reject and send back several complete cases based on the lot number. We ran a little experiment and randomly pulled 6" of tape from various manufacturers. They have all been hanging on my door and they’re all fading equally. None have faded completely but the stripes are 30% to 60% gone. Of course that's before any sterilization. Don't fall for the location myth until the vendors provide you with data that proves otherwise.” Manager CSR, _________ Hospital6 All reusable medical devices, especially surgical instruments, must be sterilized before being returned to use. Chemical Indicators (CIs), including steam sterilization indicator tape, play a major role in validating that all of the sterilization cycle parameters were met at the end of a cycle. Without this validation, the load must not be used and you must investigate the cause of the failure. If the indicator tape fades during storage, that presents another set of issues. Unless and until the steam sterilization tape manufacturers find a way to make ‘lead free’ tape that doesn’t fade over time, you’ll have to exercise care before using a load/tray where the tape has faded while in storage. One simple solution is to continue to remember that sterility is event related and not time related. If the packaging has not been compromised then the contents are still sterile, regardless of whether or not the indicator tape has faded, 1 AAMI Member Discussion Group, October 2, 2019 2 AAMI Member Discussion Group, October 4, 2019 3 AAMI Member Discussion Group, October 7, 2019 4 AAMI Member Discussion Group, October 8, 2019 5 AAMI Member Discussion Group, October 14, 2019 6 AAMI Member Discussion Group, October 18, 2019