At the 2016 Annual PDA conference in San Antonia, TX a poster was presented that looked at the effects of gamma sterilization on cleanroom garments. Since 70% of the contaminants from cleanrooms are related to people, which is with the protection of bacteria containing elements such as cleanroom suits that are required adornment for all personnel operating in cleanrooms, the assessment of their durability can greatly impact the sterility assurance of the products produced in these rooms.
The group from DuPont presented a study that looked at the “wear and tear” of cleanroom garments – both disposable and non-disposable and their ability to perform appropriately. Most companies that perform cleanroom operations on a daily basis will purchase a cleaning service for their garments rather than using single use disposable garments. The reasons are many as reusable garments are less costly, more comfortable and environmental. The authors detailed that cleanroom workers shed large numbers of particles and bacteria. During aseptic processing activities sterile garments are required and any impact on their function is critical if you are not working within isolators. They considered several properties of sterile garments:
- Garment cleanliness and particle shedding
- Ability of the garment to contain contamination coming from the wearer
- Sterility for processes/products that require it
- Garment durability
The results were recommended assessing life cycles of garments (disposable garments should not be used more than once). Garment physical properties are impacted with multiple sterilization cycles and these impacts are not always visible. They found that tear strength decreased, particle filtration efficiency decreased and particle shedding increased as a function of increasing radiation exposure due to multiple sterilization (cleaning) cycles.
They recommend having a procedure in place that will evaluate the point at which reusable garments are being negatively impacted or when they reach their useful life especially if sterile processes are not enclosed in an isolator environment.
For more information about this study please contact Jennifer Galvin at DuPont Protection Solutions.