Aseptic processing isolators are a key advancement in contamination control, offering a sealed environment to protect sterile products. A cornerstone of their effectiveness is the vapor phase hydrogen peroxide (VPHP) decontamination cycle. However, the success of VPHP doesn’t start with the cycle itself—it hinges on proper cleaning.
Why Cleaning Precedes Decontamination
VPHP is a surface-acting biocidal agent. Its effectiveness depends on direct contact with the isolator's interior surfaces. Any residue, particulate, or soil left behind from prior processes creates a barrier that can prevent VPHP from fully neutralizing contaminants.
Simply put, if it’s not clean, it can’t be decontaminated. This concept underscores the critical relationship between cleaning and VPHP effectiveness.
The Challenges of Cleaning Isolators
Isolators are designed for sterility but present unique challenges for cleaning due to their:
- Accessibility: Tight spaces and hard-to-reach surfaces require ergonomic tools to ensure every inch is cleaned effectively.
- Specialized materials: Surfaces like 316L stainless steel and glass are durable but need non-abrasive, non-shedding tools to avoid damage and potential contamination.
- Visual deception: Surfaces may appear clean to the naked eye but harbor subvisible particulates that only advanced techniques or proper lighting can reveal.
A meticulous approach to cleaning is essential to ensure these challenges don’t compromise decontamination cycles.
Best Practices for Cleaning Isolators
1. Focus on Particulate Removal: Cleaning should concentrate on eliminating visible and subvisible particles. Biocidal action is not required during this stage because VPHP will address any microbial contaminants.
2. Use the Right Tools: Non-shedding wipes, lint-free mop pads, and tools designed for ISO 5 environments are crucial. These tools should be chemically resistant to withstand VPHP and other cleaning agents.
3. Employ Proper Techniques:
1. Single-pass, overlapping strokes prevent redistribution of particles.
2. Regular training ensures all personnel understand and execute consistent cleaning protocols.
4. Tailor Tools to the Isolator Layout: Cleaning tools must be adaptable to the isolator’s design, including robotic arms, tight corners, and occluded areas.
Cleaning as a Key to VPHP Success
Even with a validated VPHP cycle, poor cleaning can render the decontamination ineffective. Here’s why:
- Blocked Surfaces: Residue or soil blocks VPHP from reaching surfaces, creating potential contamination hotspots.
- Reduced Biocidal Efficiency: Uneven surfaces caused by residue can prevent the consistent distribution of hydrogen peroxide.
- Cycle Fragility: The effectiveness of VPHP depends on ideal conditions, which are compromised when cleaning is inadequate.
Real-World Implications
Imagine an isolator that appears visually clean after production but hasn’t been properly cleaned. Residual particulates might be invisible under standard lighting but are significant enough to hinder VPHP contact. The result? A validated decontamination cycle that doesn’t meet its biocidal targets.
Proper cleaning ensures:
- Uniform VPHP distribution across all surfaces.
- Repeatable cycle success, reducing downtime and rework.
- Regulatory compliance, avoiding issues during inspections.
The Path to Cleaning Excellence
Here’s how manufacturers can elevate their cleaning process to support effective VPHP decontamination:
1. Understand the Isolator Layout: Know the airflow, surface materials, and occluded spaces to tailor cleaning strategies effectively.
2. Collaborate with Vendors: Leverage the expertise of suppliers who specialize in tools and techniques for cleanroom and isolator cleaning.
3. Focus on Training: Regular training ensures operators understand the importance of cleaning and execute protocols correctly.
4. Measure Effectiveness: Techniques like total organic carbon (TOC) or ATP swabbing can validate cleaning procedures and identify areas for improvement.
Takeaways for Cleaning and VPHP
1. Cleaning must precede decontamination—residue or particulates can compromise VPHP effectiveness.
2. Proper tools, techniques, and training are essential for consistent cleaning.
3. Cleaning ensures VPHP decontamination cycles achieve robust and repeatable results.
4. Collaboration with vendors and thorough understanding of isolator layouts can optimize cleaning strategies.
Conclusion
Cleaning isn’t just a precursor to VPHP decontamination—it’s the foundation. Without proper cleaning, even the most advanced isolator and decontamination cycles cannot deliver the expected sterility. By prioritizing cleaning, manufacturers can maximize the potential of VPHP, ensuring their isolators operate at peak performance and produce safe, sterile products every time.
This blog was based on Joe McCall’s webinar “Contamination Control in Automated Environments” at the Cleanovators Virtual Summit on October 23, 2024.
Contact a sales representative for more information on Contec Cleanroom products and how they can enhance your cleanroom cleaning procedures.
