Hand Washing: Reduce Bioburden & Microbial Contamination in Cleanrooms

April 07, 2022
by SeerPharma

Human skin is home to many colonies of microorganisms referred to as skin microbiota or skin flora. In addition to these resident microorganisms, human skin may become contaminated by foreign organisms that are transferred from the environment or other parts of the body (i.e. respiratory exhalation, different skin areas).

Although these organisms serve an essential purpose, such as protecting humans from pathogenic microorganisms, these colonies can be harmful and can cause illness or disease as they can be a source of contamination when manufacturing pharmaceuticals in a sterile environment. It is fortunate, that they are easily removed by good hygiene and washing.

The pandemic has reminded us how effective the simple process of washing our hands can be in reducing the spread of viruses and bacteria (microorganisms).

Hand washing

Hand washing should be included in your company’s contamination control strategy and be embedded into operator(s) training, and documented in an appropriate procedure:

PIC/S Guide to Good Manufacturing Practice Part I, Chapter 2:

  • Detailed hygiene programs should be established and adapted to the different needs within the factory. They should include procedures relating to the health, hygiene practices and clothing of personnel… Clause 2.15 (part)
  • Personnel should be instructed to use the hand-washing facilities. Clause 2.21

PIC/S Guide to Good Manufacturing Practice, Annex 1 – Manufacture of Sterile Medicinal Products

  • High standards of personal hygiene and cleanliness are essential. Clause 39 (part)
  • Changing and washing should follow a written procedure designed to minimise contamination of clean area clothing or carry-through of contaminants to the clean areas. Clause 41

US FDA 21 CFR 211.28 (b), Eudralex V4 Annex 18: GMP Guidelines for Active Pharmaceutical Ingredients and ICH Q7A GMP for API Clause 3.20

  • Personnel shall/should practice good sanitisation and health habits

As can be seen from the references above, many requirements from the written regulations can be quite prescriptive in some cases yet generalised in others. This has led to companies addressing these requirements in a variety of ways.

The general requirements to have good hygiene practices are echoed across different regulatory agencies; however, the specificity of these practices is lacking. The PIC/S Guide to GMP Part I goes further to specify that personnel should be instructed to use the hand washing facilities. How hand washing is performed is left to companies to decide.

Typically, companies will have detailed procedures for donning and doffing gloves and gowns, which involves validating this process for each operator.

  • Does your procedure consider hand washing as part of this validation or perhaps a separate protocol for the skill/competency?
  • How do you ensure that the documented hand washing procedure is applied by operator(s) and staff?



Why do you need effective hand washing as part of your contamination control strategy? (aside from the fact that the regulations call for it in some form).

Why do I need to wash my hands if I’m aseptically donning gloves?

The process of hand washing aims to achieve the following.

  • Remove debris and microorganisms (both resident or transient) from the nails, hands and forearms
  • Reduce the resident microbial count to a minimum, and
  • Inhibit rapid rebound growth of microorganisms


  • First, remove all hand and wrist jewellery, i.e. rings, bracelets, watches, to allow all skin surfaces adequate exposure to the hand hygiene product used
    • If you’re looking to comply with PIC/S Guide to GMP, this should be a no-brainer!
    • PIC/S Guide to GMP, Annex 1: Wristwatches, makeup and jewellery, should not be worn in clean areas. Clause 40.
  • Ensure fingernails are clean, short and unvarnished/unpainted

Hand washing with soap and water (entire process duration 40-60 seconds)

  • Wet hands with running water
    • Cold or warm water is preferable as if the water is too hot, it may irritate the skin or impact the outer protective layer
  • Apply enough soap to cover all hand surfaces
    • What kind of soap? The kind specified in your approved procedure, of course!
    • An ideal soap would have broad-spectrum antimicrobial activity against pathogenic organisms that can work rapidly before being rinsed off.
  • Rub your hands together for at least 20 seconds, ensuring that the commonly missed areas such as fingertips, interdigital areas, thumbs, and wrists are washed thoroughly
    • Refer to WHO guidelines on hand hygiene for techniques to ensure all surfaces are adequately washed
  • Rinse your hands with running water, making sure that all the soap is removed from your hands
  • Turn off the tap (if required), taking care not to re-contaminate the hands when doing so
    • This is where good hands-free design comes into play; automated/censored taps are best to practice eliminating the need to turn taps on/off and minimise the potential for re-contamination at this point.
  • Dry your hands thoroughly using a method that does not re-contaminate the cleaned hands. i.e. single use paper towel, an air dryer fitted with a HEPA filter. Don’t leave any moisture on the hands that could encourage bacteria growth.
    • If using an air dryer, consider the technique required to avoid re-contamination – keep your hands apart, avoid rubbing hands together as this may disturb the clean skin and encourage bacteria below the surface to emerge don’t allow water from one hand to contaminate the other when dry.

Ensuring basic hand washing practices are followed and adhered in your sterile manufacturing environment can limit the possibilities of contamination occurring. Hand washing is just one of many basic practices that need to be followed to ensure effective contamination control. Contamination control is incredibly important, if not done correctly can place your patients and operations at risk.

A recent example of complete disregard for contamination control in a sterile manufacturing environment led to the death of over 64 patients and caused infections for 794 patients in the US.

Keep those hands clean!

Filed Under: contamination control, hand washing, bioburden, microbiological, contamination