Solving Cleanroom Cleaning Conundrums

February 2021 - Vol.18 No. 2 - Page #2
Category: Cleanroom Cleaning Services

Pharmacy Purchasing & Products recently held a webinar
Cleaning PECs to USP Standards
presented by Fred Massoomi, PharmD, FASHP.

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

Q: How do you recommend reusable gowns be managed?

A: When managing reusable HD gowns, ensure that the gowns never cross the doffing side of the line of demarcation in the hazardous drug (HD) cleanroom suite or containment-segregated compounding area. To that end, establish a designated hanging area and provide hooks within the doffing area specifically for storing the gowns for reuse. The gown should be doffed on the dirty side of the line of demarcation, along with the outer shoe covers, and then immediately hung up. Ideally, the gown hook should be placed near the door and the return/exhaust vent, to help remove any particles from the gown.

The same approach should be taken in the nonhazardous (positive pressure) cleanroom. Again, the closer the gowns are hung to an air return/exhaust vent, the better. It is crucial to develop an SOP that delineates the circumstances under which the gown can be reused. Include criteria for the time limit to the reuse and delineate when a gown should not be reused (eg, when grossly soiled or torn).

Q: Under what circumstances is it acceptable to reuse masks?

A: Outside of the current emergent situation, masks should not be reused. However, in this time of unpredictable shortages of garb/PPE, multiple agencies have provided guidance for the proper processes for conserving and reusing garb and masks. The agencies listed below provide recommendations for managing reuse. In addition, sites should refer to their state’s regulatory bodies for further guidance.

Q: Do you recommend all compounding staff wear scrubs?

A: Ideally, all compounding staff should wear scrubs. However, USP does not mandate the use of scrubs. Sites that allow personnel to wear their street clothes into compounding areas should have an SOP detailing what clothing is acceptable as well as what clothing must not be worn (eg, sweaters, visibly filthy clothes, shoes with caked-on dirt) into compounding areas.

For sites that permit scrubs, the types of scrubs allowed should be defined (eg, low linting). As a best practice, the scrubs should be managed by the facility’s laundry services to ensure appropriate cleaning. A clean pair of scrubs should be donned for each shift, when visibly soiled, or in instances of profuse sweating.

SOPs should also address the shoes of compounding staff, to ensure they are not visibly dirty or wet (eg, from rain or snow) as this could impact the integrity of the shoe covers. Sites should seriously consider the use of dedicated shoes for personnel who work in sterile compounding areas.

Q: For vertical airflow hoods and cabinets, what is the best practice for cleaning the interior?

A: There are many techniques for cleaning the PEC, and some manufacturers differ in their recommended approach to cleaning. One of the best articles on cleaning sterile compounding spaces, including PECs, is PP&P’s Practices to Drive Effective Cleaning–Part 2 by Kate Douglass and Abby Roth.1 Defer to the cleaning recommendations made by the PEC manufacturer alongside supplemental information from the literature. USP <797> provides some guidance in section 7 stating: Cleaning must be performed in the direction of clean to dirty areas, which can be applied to the PEC based on the location of the HEPA filter (ie, ceiling or back wall).2

Q: If the anteroom fails surface or air microbial testing, should the beyond-use dates (BUDs) be decreased for all CSPs in the buffer room?

A: It depends. Cleanroom suites and segregated compounding areas are not sterile environments. In fact, compounding environments are expected to have a “natural flora.” However, there is a reason for concern when USP defined actionable levels are met or exceeded, and when problematic pathogens grow (eg, fungi, Pseudomonas spp., Bacillus sp, Burkholderia sp, etc).

Culture results are historical moments in time (up to 72 hours post-culture results) reflecting the time the sample was collected and the events immediately previous to sampling (eg, cleaning, compounding, garbing, hand hygiene, etc). If a site receives growth notification on a report, an investigation should ensue. At a minimum, the space and surfaces should be cleaned, followed by re-culturing.

Investigations should review personnel processes, cleaning procedures, and documentation gaps for required procedures. Based on the investigation and the re-sampling, sites may need to adjust the BUDs of products, particularly if the source(s) of the contamination is not able to be corrected, and sampling results are persistently positive. USP <797> clearly states the parameters to consider in establishing a BUD: “The BUDs for CSPs in Table 10 and Table 11 are based primarily on factors that affect the achievement and maintenance of sterility, which include, but are not limited to, the following: Environment in which the CSP is prepared (e.g., PEC in a cleanroom suite or SCA)…” where the environment is defined by temperature, humidity, pressures (if required), and limitation (below action levels) of viable and nonviable particles.2 Sites should have an SOP that clearly outlines when BUDs need to be adjusted.

Q: Is it acceptable to use a sporicidal on a daily basis?

A: Sporicidal products are extremely caustic cleaning agents. Many contain sodium hypochlorite, which, if used frequently, will pit stainless steel and may cause rouging (ie, rusting). USP <797> succinctly outlines the frequency of the use of sporicidal agents, only requiring the use of a sporicidal cleaning agent on a monthly basis. I would be particularly cautious about expanding this frequency as no additional benefit will be realized.

Q: Should all cleaning products be fungicidal?

A: USP requires the regular use of a germicidal agent along with the monthly application of a sporicidal agent. The term germicidal is generic and can be broken down into the EPA regulated 5-cidal activities: sporicidal, bactericidal, fungicidal, virucidal, and tuberculocidal. Terms such as kills bacteria, kills Staphylococcus, kills C. diff spores, and kills viruses, are not acceptable in lieu of meeting the EPA 5-cidal defined activities. Sites should look for an easy-to-use, broad spectrum cleaning agent to cover all potential pathogens. Some state boards of pharmacy may establish specific characteristics for cleaning agents; for example, requiring the use of sterile cleaning agents, as not all cleaning agents are sterile.

It is critical to recognize that the desired activity of a cleaning agent necessitates following the manufacturer’s established dwell time (ie, wet time on a surface prior to wiping) to elicit the specific -cidal activity. Given the frequency of room air changes (ie, at least 30 ACPH in an ISO 7 secondary engineering control) and the additional airflow from the PECs, the application of a -cidal agent must be sufficiently long to avoid the risk of the surface drying out before the dwell time has elapsed. These instructions should be included in training materials and SOPs.

Q: USP <797> 2008 requires cleaning and disinfection be done every 30 minutes of continuous compounding; but, USP <797> 2019 says the compounding area should be disinfected with sIPA every 30 minutes of compounding. What approach is best practice?

A: In my opinion, waiting 30 minutes is too long between cleanings, given the number of procedures, supplies, and movement within the PEC that can occur within 30 minutes of compounding. Best practice is to clean with a germicidal agent followed by a sterile disinfectant between each unique drug or patient dose to prevent any potential cross contamination between products. Additional cleaning is required should a spill occur; spills should never be left to address at a later time. Using EPA registered one-step cleaning and disinfecting agents can make this process more efficient.

Q: What additional cleaning, if any, do you recommend in the sterile product area to address COVID?

A: The CDC has outlined the cleaning process to address SARS-CoV-2. As this is a continually evolving process, I defer to the CDC website on cleaning. It is important to note that even if a cleaning agent is listed as virucidal, one must not assume that it will be effective against the SARS-CoV-2 virus. Instead, refer to the latest list of disinfectants with activity against SARS-CoV-2 virus on EPA’s List N.

Q: How should existing rust spots on equipment be addressed?

A: Rust or rouging may be present on any exposed metallic surface. Stainless steel does rouge, and this can be accelerated by continued exposure to oxidizing cleaning agents. Rouging can occur on the PEC work surface where cleaning solutions collect and pool as well as in nicks due to pitting or tapping of vials, as that can remove the finished surface of the stainless steel, exposing the under surface to oxidizing cleaning agents. Additional fixtures within a PEC that are not stainless steel, such as gas line ports, outlets, outlet covers, bolts, IV poles/and holders, can all rouge.

Rouging can also occur outside of the PEC. Look for nicks on the external, painted surfaces of the PECs. If nicks are present, they should be painted immediately with a sealing paint that is approved by the manufacturer of the PEC. The Steris Corporation has published a guide to addressing rouge on stainless steel surfaces and notes that professional consultation may be warranted based on the type and extent of the rouging. Rouge is a contaminant and over time it can produce nonviable particles and harbor viable pathogens. The best way to address rouging is to prevent it.

Q: How can chemical residue and rust from peracetic acid use be prevented?

A: USP <800> states:

Damage to surfaces is exhibited by corrosion to stainless steel surfaces caused by sodium hypochlorite if left untreated. To prevent corrosion, sodium hypochlorite must be neutralized with sodium thiosulfate or by following with an agent to remove the sodium hypochlorite (eg, sterile alcohol, sterile water, germicidal detergent, or sporicidal agent).

Reach out to the manufacturer of the specific peracetic acid product(s) to get direction on how to properly neutralize their cleaning agent if rouging is occurring or is a concern.

Q: How should the grate in front of the HEPA filter be cleaned to avoid damaging the filter?

A: The protective HEPA filter grates for PECs and ceiling units may sit directly in front of the HEPA filter or be positioned with space between the grate and filter. In either scenario, pour a small amount of cleaning solution (ie, non-dripping) onto a low-lint wipe and gently wipe the grate in the defined direction. Be careful to not press the wetted wipe into the grate. It is extremely important to not wet the HEPA medium due to the potential for filter damage.


  1. Douglass K. Roth A. Practices to Drive Effective Cleaning–Part 2. Pharm Purch Prod. June 2020; 17(6):18-22.
  2. USP General Chapter <797>. Pharmaceutical Compounding – Sterile Preparations. Second Supplement to United States Pharmacopeia and National Formulary (USP 42-NF37). June 3, 2019. Accessed 12/17/20.

Fred Massoomi, RPh, PharmD, 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.


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