Sterile Isopropyl Alcohol (IPA) 70% use is indispensable in any compounding-controlled environment. Many may recall when IPA 70% was the only product used to “clean” the IV room and some may even remember the days before sterile IPA 70% was available. In this blog post, we are going to dig a little deeper to understand the proper use of sterile IPA 70% in cleanrooms and describe the “true” and intended use.
Current 2008 USP <797> does a very poor job at explaining cleaning of controlled areas. It simply states that ISO classified areas must be “cleaned and disinfected”. The chapter leaves it to personal knowledge and interpretation of what exactly cleaning and disinfecting entails. However, the new 2021 revision of USP <797> does and exceptional job explaining the cleaning and disinfecting process.
For this, we will pull from some definitions from the new 2021 revision:
Cleaning Agent: A product that removes organic/inorganic substances using a mechanical process with water and a surfactant.
NOTE, the word “surfactant”. The intent of cleaning is to use chemical bonds of organic and inorganic substances and that of a surfactant, much like we use soap on hands, to remove particulate matter from surfaces.
Sterile Isopropyl Alcohol (IPA) 70% is NOT a cleaning agent since it is not a surfactant
Disinfecting Agent: A product that has appropriate germicidal action, killing/deactivating microorganisms (bacteria, virus, fungi).
Sterile IPA 70% is insufficient at a disinfectant for our clean rooms. While it has broad bactericidal and fungicidal coverage, but it does not kill all virus.
Due to the volatile nature of sterile IPA 70% and that the dwell time (see below) varies from 10 seconds to 1 hour makes it unpractical to use only on its own.
Sterile IPA 70% could be considered a sanitizer (reducing microbial growth) but not a disinfectant (appropriately killing/deactivating microorganisms)
Sporicidal Agent: Is a part of disinfection but specifically pertaining to the act of removing spores and/or spore-forming microbes
Sterile IPA 70% does not have any sporicidal activity. The very reason sterile IPA is mandated is because spores can survive inside IPA 70%. The sterilization process removes any spores from IPA 70%.
Use of unsterile IPA 70%, contaminated with spores, could lead to a microbial infestation with spore-forming microbes.
Dwell time: This is the amount of time a product (cleaner, germicidal, sporicidal) must remain on a surface to be effective at its stated claim(s).
This is an EXTEREMELY important concept. If employees do not understand this concept, then areas will not be clean.
Sterile IPA is NOT:
a cleaning agent (does not contain a surfactant)
a disinfecting agent (does not kill all microbial growth)
a sporicidal agent (does not denature spores, spores can live in IPA 70%)
IPA is ideal to use for:
IPA is only sufficient in our clean rooms IF other products are used (the true cleaning agents containing a surfactant, and disinfectants that are germicidal and sporicidal).
IPA is an excellent sanitizer, able to help keep microbial contamination down, if the other products are in use.
IPA is excellent at removing residue left behind by cleaning products (The KEY action for sterile IPA 70% use).
Residue Removal: The underestimated quality of sterile IPA 70%
Sterile IPA is essential in reducing microbial growth in controlled environments due to its broad (although incomplete) germicidal coverage, but its key contributing function is that of residue removal.
Cleaning agents (with surfactant) and disinfecting agents (that are germicidal/sporicidal) leave behind residues and sterile IPA 70% excels at removing these residues. If residues are not removed regularly, the result is a sticky situation that creates problematic areas that are ideal for microbial growth.
Buildup of residue is not seen that often in the PEC (hoods) since use of sterile IPA 70% is mandated after any cleaning/disinfecting agent used inside of the PEC. However, high touched areas may be problematic if sterile IPA 70% is not used throughout the workday, in between cleaning and disinfecting agents. NOTE: Floors can be one of the most residue-heavy surfaces in classified rooms from the daily use of cleaning/disinfecting agents. However, use of sterile IPA 70% on floors should be discouraged because it can eventually damage the floor, resulting in a more dangerous scenario. Use of sterile water for injection/irrigation (not tap or anything other than sterile) and wiping dry is the best way to remove residue from floors.
Sterile IPA 70% is a necessary multipurpose agent used daily to maintain cleanliness and to remove problematic residues left behind by other products used to clean and disinfect environments. However, it must be recognized that sterile IPA 70% has limitations and is only sufficient if the other cleaning/disinfecting agents are incorporated in the daily processes. When cleaning and disinfecting is mandated, sterile IPA 70% must never be substituted for other products containing surfactants with appropriate germicidal/sporicidal activity.
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