Maintaining PECs and C-PECs

September 2021 - Vol.18 No. 9 - Page #28
Category: Cleanroom Cleaning Services

Pharmacy Purchasing & Products recently held a webinar entitled:
Maintenance and Upkeep of PECs and C-PECs
presented by Fred Massoomi, PharmD, BCSCP, FASHP

The following questions were submitted by attendees.
The webinar slides and full presentation can be downloaded at

Q: Is rust a contamination risk when it presents as discoloration as opposed to surface damage?

A: Stainless steel can rust, and rusting can occur when surfaces are not appropriately managed. According to the US FDA’s 2020 Insanitary Conditions at Compounding Facilities Guidance for Industry document, rust is an indicator of contamination.1 Rust is listed in three locations defining an insanitary condition of a facility engaged in compounding, specifically:

  • Sources of foreign matter in the ISO 5 area (eg, rust, glass shavings, hairs, paint chips)
  • Foreign matter in the production area (eg, rust, glass shavings, hairs, paint chips)
  • Production areas or equipment that are difficult to clean or contain porous, particle-generating, or visibly dirty (eg, rusty) equipment or surfaces (eg, shelving, floors, walls, doors, ceilings)

Stainless steel exists in varying grades relating to its composition (primarily iron, chromium, nickel) of the steel and other base materials (molybdenum, manganese, silicon, phosphorus, carbon, sulfur, related alloys, nitrogen, and copper) and these components may react with cleaning solutions.2 Surfaces that are rich in iron (stainless steel) that are exposed to highly oxygenated environments (cleanrooms) have the potential to provide a nutrient-rich breeding ground for certain pathogens to grow on if not managed and cleaned properly.

During inspections of compounding areas, inspectors (state board of pharmacy, FDA) will quickly identify discoloration as contamination, and they will document the issue. Hence, rust, corrosion, and discoloration of stainless steel should be formally addressed.

Q: What is the best way to address discoloration on stainless steel surfaces in the primary engineering control (PEC)?

A: Staining and color discolorations within the PEC may be due to rust and/or the corrosion of the stainless steel or its components. For example, welded seams and the materials used during the welding process may not be stainless steel, which may present an opportunity for staining, corrosion, and rusting. All of the materials used to fabricate the PEC may contain components that may react when drugs and cleaning solutions come into contact with the surface.

The first step to formally addressing discoloration of a PEC surface and its components is to work with the manufacturer of the PEC to determine the cause of the discoloration. Then, contact the cleaning solution vendor; collaboratively, both groups should be able to provide a cleaning agent and process specific to the discoloration, in addition to guidance on cleaning options to eliminate the staining.

Of note, there are several drugs that have the potential to stain surfaces, such as doxorubicin (red), mitomycin (blue), mitoxantrone (blue), methylene blue (blue), indocyanine green (green), injectable iron preparations (black/brown), and multivitamins (brown/tan).

If the stain remains despite these efforts, it may be worthwhile to culture it to determine whether it will elicit any growth and document the steps taken to address the issue. Having documentation is especially important in the event of an inquiry during an inspection.

Q: How do you recommend addressing rust inside the PEC?

A: As I noted, first contact the manufacturer of the PEC and then contact the vendor of the cleaning solutions being used. Protocols to address rusting will differ based on the cleaning solution(s) being used, where the rusting is occurring, and the severity of the rust (eg, from color changes to corrosive flaking). Remediation of rust can be difficult, and solutions may only slow the inevitably evolving rusting process.

The presence of rust on just a portion of the cabinet may indicate that the stainless steel is incompatible with the cleaning solution(s) in use. In this case, sites may need to incorporate a “rinse” step to the cabinet with sterile water or sterile IPA to ensure that the residue is removed once it has gone through its proper solution dwell time.

For areas of major concern (eg, surfaces in direct contact with sterile preparations), the cleaning process for rust may involve the use of cleaning solutions specifically designed for removing rust. In more severe cases, based on the extent of the rust, the affected area may require a multi-step process of cleaning, light sanding, and disinfection. The derusting (derouging) process can be potentially caustic. Review the Safety Data Sheets for proper handling and use of chemical cleaning agents prior to use. It is important to note that utilizing these special chemicals and cleaning steps can potentially remove the original protective surfaces applied to the PEC and its components, such as screws/IV bar holders/gas ports/outlet covers, so there may be a need to replace those affected parts.

The best approach is to prevent rust in the first place, and if it does occur, utilize a validated cleaning process to properly remove the damage.

Q: When doing a paint touch-up for exposed metal/rust on the exterior of a PEC, what steps would you recommend prior to resuming compounding?

A: The only process that must occur during compounding is compounding, to minimize contamination of products. Since prepping and painting represent a “dirty process,” any paint touch-up distinctly precludes compounding until the cleaning is complete. I would highly recommend cleaning the surface prior to the paint touch-up, which means sites will need to cease compounding at that point. Once the paint has dried and prior to resuming compounding, conduct an enhanced cleaning process incorporating the approved germicidal and sporicidal cleaning agents. It is important to document the painting event, cleaning date/time, and the products used, should there be any future issues in that space. If a major paint job is required (eg, the entire base of the PEC), it might be time to consider replacing the PEC.

Q: Following a HEPA filter change, is hood recertification necessary?

A: Hoods absolutely require recertification when HEPA filters are changed. Whenever any maintenance is performed on a PEC, the hood will need to be recertified prior to use. The certification process does four things: ensure the PEC meets defined specifications for compounding sterile preparations (ISO 5 classification), ensure the filter did not sustain any damage during the installation process, ensure the fan distributes an adequate amount of air equally across the surface of the HEPA filter, and detects the presence of bacterial pathogens. Changing a HEPA filter can be an extremely dirty process due to historical spill residues and the work itself to remove the filter. If the HEPA filter is to be changed out within a cleanroom suite, no compounding should take place during the work and an enhanced cleaning process (incorporating the approved germicidal and sporicidal cleaning agents) of the PEC should take place after installation of the new HEPA and prior to culturing. Additionally, the PEC with the new HEPA cannot be used until the certifier has approved the unit for sterile compounding.

Q: Do you recommend outsourcing PEC maintenance over conducting it in-house?

A: I do believe, as a best practice, utilizing an outsourcing vendor for PEC maintenance, such as a contracted certifier of cleanrooms, gives the advantage of knowing the maintenance is being conducted by a qualified and certified expert. However, as sites establish in-house expertise in compounding areas, they may become more comfortable allowing designated staff experts to manage and oversee very basic PEC maintenance. For example, maintenance such as changing lightbulbs, changing pre-filters, replacing easily accessible parts that do not impact the function of the PEC (screws, IV pole holders, etc.) can be conducted by the in-house engineering departments.


  1. U.S. Food and Drug Administration. Regulatory Information. FDA Guidance Documents. Insanitary Conditions at Compounding Facilities Guidance for Industry document: Docket Number FDA-201-D-2268. November 2020.
  2. Gonzalex M.M. Rouge: the intrinsic phenomenon in 316L stainless steel – a key material for biopharmaceutical facilities. Pharmaceutical Engineering. 2012:32(4):1-8

Fred Massoomi, PharmD, BCSCP, FASHP, is senior director of hospital and health-system pharmacy for Visante, Inc. He received his doctorate from the University of Kansas School of Pharmacy. Fred is a member of PP&P’s Editorial Board.

Role of Environmental Monitoring in the Cleanroom
Led by Patricia Kienle, RPh, MPA, BCSCP, FASHP
FRIDAY, OCTOBER 15 | 1:00-1:20pm ET
To view and register for upcoming webinars go to


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