Best Practice: The Importance of Removing Sporicidal and Disinfectant Residue

Pharmaceutical facilities follow a strict microbial contamination control program for cleanrooms. But, what if these solutions are a source of future contamination? It’s a problem in the pharmaceutical, biotech, and medical device industries, but one that’s easily remedied.

Regulatory agencies, including FDA and the European Medicines Agency (EMA), expect GMP manufacturers to implement a robust decontamination program for their cleanrooms. The approach most routinely used by pharmaceutical manufacturers includes a rotation of one or more disinfectants with a sporicidal agent. These products are formulated with multiple ingredients that are essential for their performance and stability, but their regular repeated use can result in buildup on surfaces over time. This buildup poses visual, safety, and product integrity threats, including: sticky or slippery floors and doors, streaks and discoloration, and contamination. Something that doesn’t look clean can cause issues during an audit for general housekeeping. Residue could be a source of future contamination by giving microbes a place to hide and could potentially be a food source for bioburden. Residue can also lead to an increase in overall particle counts in the cleanroom, and particles can flake off curtains or other surfaces and get into drug products.

Ways to remove residue
In most cases, 70% isopropyl alcohol (IPA), purified water (PW), or water for injection (WFI) can be used for removing residue. IPA is most appropriate for glass windows, most cleanroom furniture and equipment, and stainless-steel equipment while purified water or WFI is better for residue removal on larger surfaces, such as walls, floors, and ceilings. These rinsing applications should be done only after the sporicide or disinfectant has been applied for the desired wet contact time and allowed to dry. If a surface is rinsed too soon, this can dilute the disinfectant and may actually reduce the effectiveness of the microbial control program.

All cleaning and rinsing agents used in ISO 5 cleanroom operations should be sterile and applied with sterile equipment and supplies, such as wipes and mops.

How often?
Residue removal is necessary for a complete cleaning and disinfection program and should be performed as needed, based on how the surface looks and feels. If it’s completed on a routine basis (i.e., weekly, monthly, or quarterly), water (alone) may be appropriate. If the removal step has never been implemented or there’s significant residue buildup or hard-to-clean soils, a formulated cleaner may be required. If a formulated cleaner is used, a water rinse step should follow.

A well-defined residue removal program can be fairly simple to implement with the proper training. By incorporating a surface rinsing protocol into standard operating procedures, pharmaceutical manufacturers can prevent long-term buildup of disinfectant and sporicide residues in aseptic processing areas. Ultimately, this produces better aesthetics, improved safety, and a reduced risk of contamination in products.

About the Author
Jim Polarine is senior manager, Technical Services at STERIS Life Sciences, Jim_Polarine@steris.com.