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What You Need to Know about Cleanroom Fogging

What You Need to Know about Cleanroom Fogging

Going beyond baseline protocols to safeguard your facility

Steve Gonzales

Steve Gonzales is CEO of Technical Safety Services, which provides testing, certification and calibration of equipment and controlled environment crucial to the success of the biopharma, medical device, academic research,...

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The importance of cleanliness to keep ourselves safe and free from disease has never been more apparent. For those that work in a cleanroom or laboratory, deep cleaning practices and protocols are already very familiar—the importance of order and cleanliness is likely second nature. 

In cleanroom and laboratory work, cleanliness and contaminant control is not only critical for lab staff health and safety, it also has an impact on the end users of the product being manufactured. In many cases, these products will be interacted with by vulnerable people—those who are acutely or chronically ill, and for whom contaminant control is a paramount concern.

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For this reason, the importance of proper, thorough cleaning protocols cannot be overstated. Beyond the human impact, contamination events can also result in a major negative impact on facility operations, project timelines, and the overall budget or bottom line of a facility.

Beyond baseline protocols: Implementing cleanroom fogging

Standard cleaning protocols are already part of the daily practices of every cleanroom and laboratory. They would not be able to continue operating as such if this were not the case. 

These steps—usually undertaken at shift start, shift end, and throughout the working period—can include:

  • Surface wipe downs and disinfecting
  • Use of fume hoods
  •  Ingress and egress protocols for personnel
  • Air filters and circulators
  • Controlled access

While each of these steps is highly effective, particularly when working in conjunction with the other steps, there are always additional methods that can be implemented. Otherwise, contaminant outbreaks would never occur. 

Cleanroom fogging provides an additional defense mechanism and safeguard by addressing:

  • Airborne particles, including mold and spores, that may not have been circulated or trapped by a filter due to the design and geometry of the cleanroom or lab, among other factors
  • Heavy microbial loads that may build up in the ambient air, exceeding the capacity of the filtration system
  • Surface molds and spores against which standard wipe downs and disinfectant methods are not effective
  • Microbial material that may have permeated surfaces
  • Scenarios where continuous air circulation is not in place

Fogging works by saturating the air in a facility with an antimicrobial medium to attack and neutralize unwanted contaminants. Fogging is most typically associated with airborne particles, but it can also be a supplemental aid in keeping surfaces clean, due to the thorough saturation of the fogging material.

Types of fogging

Fogging media can take many forms, each with strengths, weaknesses, and applications. 

Common types of fogging include:

  • Hydrogen peroxide and silver ion solution: One of the most used fogging methods, the hydrogen peroxide and silver ion solution is injected into the facility, and is recirculated to fully permeate the air—at which time the charged ions help to attract unwanted contaminants—and is then aerated or diluted to disperse the solution. The cycle typically takes four hours, and is safe for nearly all applications, provided proper dispersal occurs and surfaces are wiped afterward.
  • Ozone: With cycle times between 30 minutes and 90 minutes, ozone can prove a quick and effective solution for general fogging needs. Ozone reacts with many common contaminants to neutralize them, and will then quickly break down into a safe byproduct. 
  • UV light: UV light is frequently used in fogging scenarios where a “no-touch” process is required or desired, requiring less preparation and no requirement to clean surfaces or residue afterward.
  • Aerosolized disinfectants: In some cases, standard disinfectants are aerosolized and dispersed into the cleanroom. This method is convenient if no additional contaminants are suspected to be present beyond those that can be addressed by the disinfectant. Materials such as fungi and molds will require a stronger method than those described above.

These descriptions and tips are an excellent start in implementing fogging as an additional cleaning and disinfecting step in your facility. There are many more fogging methods available. Though with this understanding of the process in hand, lab leaders now have a stronger edge in the ongoing battle against germs, contaminants, and outbreaks.