Risk of Misinterpreting Hydrogen Peroxide Indicators: FDA Letter Concerning the Safety Risk to Patients

Earlier this year the U.S. Food and Drug Administration (FDA) was made aware of the potential to misinterpret colored hydrogen peroxide indicator strips used to validate vapor sterilization of medical devices by health care personnel who reprocess, sterilize or use reusable medical devices. The use of these chemical indicator strips creates the potential for patient harm because there is no standard indicator color for vapor sterilization to show if a device has been sterilized and safe for use. This concern for possible patient harm led the FDA to issue a letter to healthcare providers on May 7, 2020, alerting healthcare facilities to this problem. According to the FDA’s letter “During the COVID-19 pandemic, health care facilities are rapidly adopting conservation practices, including decontaminating disposable compatible N95 and N95-equivalent respirators for single-user reuse. Reprocessing staff may be using sterilization systems for the first time or concurrently using sterilization systems from different manufacturers. If staff assumes that all manufacturers use the same color code to validate sterilization, they may mistakenly release contaminated devices for reuse.”1 (Author’s emphasis) The FDA became aware of this color-coding problem after numerous healthcare facilities alerted the FDA to the lack of a standardized color to indicate that devices were indeed sterile. The FDA’s letter to healthcare providers pointed out that depending upon who the manufacturer of the chemical indicator is, the color blue can mean an unprocessed, non-sterile device or, it can represent a processed, sterilized device. Equally confusing is the fact that the color pink can represent a processed, sterilized device or, it can represent an unprocessed, non-sterile device. This lack of a standard color-code puts healthcare personnel and CS/SPD reprocessing staff in the untenable position of not being able to immediately tell if a device has, or has not been sterilized and safe for use. At the present time, there are no industry standards, nor are there any FDA requirements for the color-coding of chemical indicator strips. Manufacturers of the various brands have been left to come up with their own color schemes. As noted in the FDA’s letter, this has resulted in patient safety concerns as to whether or not a device has in fact been sterilized and is safe for patient use. What is even more confusing is the fact that the manufacturers’ various colors have been validated for the same hydrogen peroxide sterilization cycle conditions. In their warning letter, the FDA makes the following recommendations to healthcare facilities and their staff:

• Review the manufacturer’s instructions for the particular indicator bar or card being used and know the significance of the indicator colors.
• Enhance staff training on the indicators for all sterilization systems employed in the facility and reinforce that training with prominently displayed visual reminders.3

The FDA’s letter also points out that they are currently working with the various manufacturers of vapor sterilization indicator strips to improve the products’ labeling “and explore standardization for colors used to indicate sterilization.” The letter also states that the FDA will continue to keep everyone informed of any new or additional information.4 The lack of an industry standard for color-coding these vapor sterilization indicator strips represents an ongoing threat to patient safety. This threat can easily be corrected with the adoption of an industry standard for color-coding vapor sterilization indicator strips. Over 40 years ago the medical industry adopted an industry-wide, color-coding standard for all parenteral (I.V.) and enteral nutrition delivery devices. As part of the color-coding standardization, it was decided that all enteral nutrition connectors, nasogastric tubes, stomach tubes, P.E.G. tubes, Jejunostomy tubes, enteral feeding bags and pumps would be color-coded orange. This color-coding standardization was done to minimize the risk of a parenteral drug accidentally being infused into a patient’s enteral system. More importantly, it was done to minimize the risk of enteral formula being accidentally infused into the vascular system through a parenteral line, a vascular catheter (Hickman, Broviac, PICC line, etc.) or an implantable vascular access device (i.e., infusion port). While creating patient discomfort, the infusion of a parenteral drug into a patient’s gut through an enteral nutrition device is not a life-threatening event. The accidental infusion of enteral formula into a parenteral delivery device into a patient’s vascular system is a life-threatening event. This was why the medical industry went to orange color-coding for all enteral products over 40 years ago. The present lack of an industry standard for color-coding hydrogen peroxide vapor sterilization indicator strips is a clear, present and on-going threat to patient safety. The solution to the problem is the same solution that we used to solve the problem with parenteral and enteral nutrition delivery devices over 40 years ago. Manufacturers of the vapor sterilization test strips should be required to adopt and use an industry-wide, standardized color-coding system for their indicator strips. 1 FDA Letter to Health Care Providers “Risk of Misinterpreting Hydrogen Peroxide Indicator Colors for Vapor Sterilization” May 7, 2020 2 Op. cit. FDA 3 Op. cit. FDA 4 Op. cit. FDA