In this Clean Room it's Hard to Wash Your Hands
How a proliferation of microbes around a door handle exposed deeper errors of poor design. Part of our Microphyles Case series.
The mantra of the COVID pandemic might as well have been “Wash your hands!” While we hope everyone does this routinely, handwashing is a central contamination control strategy in a pharmaceutical environment.
Here we present a case study about how a proliferation of microbes around a door handle exposed deeper errors of poor cleanroom design.
This is a real picture from an injectables manufacturer. The sign on the cleanroom exit door tells you to clean (your hands) before you leave, but there’s no sanitizer in the holder.
In this cleanroom, no one’s hands will be sanitized until one of the operators wants to go through the frustration of learning where the sanitizers are stored and figuring out how they get replaced. When you’re getting your first bathroom break after hours in a cleanroom, that’s not usually high on the priority list.
The sign referenced above is related to an investigation for an environmental surface excursion. There were high counts of Staphylococcus and Bacillus species on a door surface. The door separated the personnel gowning transition zone from the rest of the ISO 9* space. Check out this map:
The red arrows depict the flow of people exiting ISO 8 rooms on their way to a break. They take off their ISO 8 gowning in the Gown-Out room, they walk through the ISO 9 area to the locker room, then they change from their scrubs back into their street clothes.
What caused the high counts on the anteroom door? It’s not a huge surprise the door is a frequent touchpoint. Management was quick to blame cleaning personnel for not cleaning the door correctly, but per SOP, the door is only cleaned once a day. Dozens of personnel walk through the door at varying times in the day and the sample could be collected at any time. It’s not realistic to expect a single cleaning to keep the door clean after everyone touches it.
By analyzing the entire flow, we determined the door had a higher risk for contamination compared to other touchpoints. It’s well known that the human skin sheds thousands of cells per hour. That’s why we wear gloves in the clean room to prevent debris from getting into products.
What happens to that bacteria when we wear gloves? Bacteria that normally sheds away are now trapped in the gloves. When we remove the gloves, some of those bacteria are trapped in the glove and thrown away. However, we’re still left with a greater bacterial load on our hands than normal. That load gets passed off onto everything we touch. In these de-gowning rooms, the first things we touch are the exit doors.
Therefore, the basic story for our door microbial hits goes like this:
- The operators wear gloves in the clean room.
- High bacteria counts are trapped against their hands.
- They remove those gloves in the de-gowning rooms.
- They unintentionally wipe this excess bioburden on the doors they touch.
- Before the next door-cleaning occurs, an Environmental Monitoring Tech picks up the bacteria during surface monitoring.
- Six days later we get the Action result that requires an investigation.
There were a couple trains of thought on how to handle this investigation. One line of thinking: Based on the root cause, the organisms posed little risk to product. The contact point was for people exiting, not entering, the clean rooms. There is little chance those organisms would be brought into the clean room. When there’s no risk to product, there’s little desire to put much effort into a corrective action.
The other line of thinking: The EMPQ determined this exact location needed frequent monitoring. The clean room validation determined that, in dynamic conditions, the cleaning program can maintain this site below action levels. Anything that causes high counts needs to be identified and fixed.
As an investigator in the Quality group, I followed the second line of thinking. I came up with a plan to address the problem without too much burden on the area managers or their team: Provide a hand sanitizer station in the exit room. This gives operators a chance to clean their hands before they touch the door.
As you can tell from the picture and the location of the sign, communication failed! The sign and sanitizer should have been placed at the gowning anteroom exit door, not the locker room exit door! I made sure to discuss the sign with the appropriate people so it could be moved. The error reminded me how important it is to follow up on corrective actions, even after it’s “confirmed” the action is complete.
Mistakes and oversight like this still happen too frequently. Area managers need to design their processes and environments for their employees’ success. Errors like this are symptoms of poor facility and process design. The area manager in the abovementioned picture did not design an appropriate system to ensure contamination control, and it’s imperative for investigations to get to root cause.
*ISO, or the International Organization for Standardization, classifies cleanrooms based on the expected number of particles per cubic meter of air. Very few particles (and by extension microorganisms) are expected in cleanrooms with low classifications. ISO 9 is the highest classification. There is no distinction between expected particle counts in ISO 9 rooms and non-classified areas.
At this facility, ISO 9 areas represented rooms with HEPA supplied (filtered) air that required company issued gowning to enter. The areas were also part of the routine cleaning and monitoring plan due to the proximity to ISO 8 rooms.
Due to the distance between manufacturing processes and ISO 9 rooms, Microbiological excursions in ISO 9 rooms did not pose a direct risk to product. But events like this pose some questions about the site’s general microbiological control: Did the site establish an adequate routine sampling plan? Are the cleaning practices acceptable? Are employees following proper aseptic techniques? Do any of these issues extend to areas where product is at risk? These are the questions inspectors ask when they see these otherwise benign events.