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Microscopic Organisms

Proactive Garbing and Behavior Considerations for Those Servicing USP <797> Customers

Nearly every certification company I have worked with has at some point had viable results come back from the lab that are off the charts. It may be something like 120 CFU/m3 of Staphylococcus, Micrococcus, and Corynebacterium species on a sample; and the counts are similar for all buffer and ante-room results. When you receive results like this, two thoughts will likely run through your mind. First, wow they are a mess! And second, oh wait, what if this was from us? You are going to have to share the results with the customer regardless of the cause. But first, you will want to determine if the exceeded results were due to poor garbing or behavior practices or sampling errors on your end. This way, when you discuss the results with your customer, you are prepared to share the corrective actions your organization is taking to prevent issues like this in the future. Trust me, they will appreciate it. 

Ideally, you never find yourself in this situation. The best way to prevent it is to implement some of your own garbing and behavior expectations for technicians who perform viable sampling for customers. This proactive approach is also something you can share with potential new customers as a selling point for your services. The key is that your policies are contained within standard operating procedures (SOPs) and that every technician is trained on the expectations.

A petri dish with specimens

Before we get into some of the garbing-related tips, let’s review some statistics and rationale as to why good personal hygiene and garbing is so important.

  1. We shed about nine pounds of dead skin cells each year.1
  2. Particles act as transport vehicles for microorganisms and introduce them into the compounding process.
  3. Human skin is home to more than a 1000 species of bacteria.1
  4. A square inch of human skin contains 50 million bacteria. On oily surfaces like the face, the number can ramp up to 500 million.1
  5. Each of us carries two to six pounds of bacteria.2
  6. Bacterial cells outnumber human cells 10 to 1.2

There are some things you can do from a personal hygiene and behavior standpoint to help minimize the microbial burden on the sterile compounding area. Implementing the suggestions listed below as part of expected work behavior for those who perform viable sampling will significantly reduce the risk of certifying personnel negatively impacting the environment and producing false-positive results. And remember, the 2019 version of USP <797> states, “individuals entering a compounding area must be properly garbed and must maintain proper personal hygiene to minimize the risk of contamination to the environment and/or CSPs.”3

Personal Hygiene-Related Suggestions

Washing hands
  1. Shower daily, preferably in the morning before work and not the night before. Showering at night results in you likely sleeping in dirty clothes and on dirty sheets. And let’s not forget the microorganisms you could pick up by sleeping with your pets.
  2. Use a moisturizer. Did you know men shed more particles than women? This is due to shaving and then using aftershave lotions that usually contain alcohol and sodium hydroxide, which will further dry out the skin.4 Although USP <797> indicates that makeup and cosmetics are not to be worn, an untinted and unscented moisturizer on the face and arms is acceptable and desirable.5 This will prevent some of the shedding that would likely occur due to dry skin. 
  3. Wear freshly laundered clothing. We are all guilty of wearing jeans more than once before we wash them. This is not an acceptable practice for those entering the compounding area. It also doesn’t mean that scrubs worn from home are the answer either, since these are now street clothes. If a pharmacy requires compounding personnel to change into hospital-laundered scrubs, they should require that vendors change too.
  4. Wear cleanable, pharmacy-dedicated shoes. By having a pair of shoes that can be wiped with an EPA-registered, one-step sporicidal disinfectant cleaner before wearing into the general pharmacy area, the risk of introducing microorganisms from shoes greatly decreases. If this is not an option, there must be some indication in your SOP that shoes worn into the compounding facility are visibly clean.
  5. Do not enter the controlled compounding environment with any skin irritation, healing tattoo, or respiratory illness. Although already likely implemented by the pharmacy, having a company policy makes it very clear as to the expectations for those servicing USP <797> customers.
  6. Remove all exposed jewelry before entering the controlled compounding environment. Just like the pharmacy, you must have a policy in place describing how you will handle implantable jewelry that would not be covered by clothing.

General Behavior Suggestions

A mask and hair nets
  1. Keep the work vehicle clean. The cleanliness of the work vehicle will impact the cleanliness of the clothing worn, equipment, and material brought into the sterile compounding facility. 
  2. Discuss garbing materials with the pharmacy customer before the first visit. Many times, pharmacies do not have garb to properly fit the certification technicians. To avoid issues during the visit, reach out to the pharmacy in advance and discuss the garbing needs of the individuals who will be servicing the location. The pharmacy is responsible for ensuring “that any person who enters the sterile compounding area maintains the quality of the environment.”3 That means providing properly fitting garb for vendors.
  3. Have a clear SOP with regard to cell phones. Cell phones are dirty, and you can expect around 2192 microorganisms per phone, which is dirtier than a toilet seat.6 Pharmacy staff have no reason to bring a cell phone into the compounding area. However, cell phones can be a useful tool for certifiers, especially when recording dynamic airflow smoke-pattern tests (and the bonus of it doubling as a calculator). You may have to work out cell phone entry with your customers (especially the wipe-down procedure), but if you can share with them that you already have a cell phone–use SOP in place, it may ease their concerns.
  4. Skip the earbuds. Certification is a grueling process, and depending on the size of the facility, it can take all day. So, the desire for entertainment is certainly understandable. However, not only are earbuds a contamination risk, but listening to music or podcasts can be a distraction from the critical job at hand.
  5. Start with the viable sampling, and only take in the equipment needed for this activity. Many certifiers will also bring in the particle counters and start the room samples. This is acceptable; just be sure to move slowly and deliberately during sampling. There are some variables affecting sampling that you will not be able to control, such as the temperature and humidity of the rooms. If you know ahead of time that a location is exceptionally warm, it may be in your best interest to send technicians that are likely to be more comfortable working in those conditions. Essentially you want to avoid sending technicians who sweat easily to locations known to be warmer. Obviously, a discussion with the pharmacy manager or designated person will be necessary to address the temperature and humidity problems, as it is likely that your technicians are not the only ones who are facing uncomfortable working conditions. These are just a few of the proactive approaches that can be initiated to reduce the risk of inadvertently contaminating viable samples. Take the time to assess the risks your organization may face, and develop some preventive actions. The goal is to avoid dealing with this issue in the future. Clear, concise SOPs and training, including the “whys,” can really make a positive impact on your service to your customers.


  1. Facts Legend. Baidya, S. 50 Interesting Human Skin Facts. 2015. Retrieved on 6/17/21.
  2. Lita Proctor. National Institutes of Health’s Human Microbiome Project. Retrieved on 6/17/21.
  3. United States Pharmacopeial Convention, Inc. <797> Pharmaceutical Compounding—Sterile Preparations (proposed 2019 version).
  4. Hauenstein LR. Cosmetics as a potential source of particulate contamination in the cleanroom. Chapter in Particles in Gases and Liquids. Plenum Press. New York. Retrieved on 6/17/21.
  5. Goldstein K. Cosmetics in cleanrooms…again? 200. Solid State Technology. Retrieved on 6/17/21.
  6. Selim HS and Abaza AF. Microbial contamination of mobile phones in a health care setting in Alexandria Egypt. GMS Hyg Infect Control. 2015. Retrieved on 6/17/21.
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