Effective Cleaning to Remove Dense Dust from Cleanrooms

While the advanced air filtration systems in modern cleanroom HVACs trap most dust particles, cross contamination from dust is still a concern. Dense dust, which has a high water content, and metal-containing dust can easily find its way into cleanrooms via things like the corrosion of faucets and plumbing or technician clothing. A careful protocol is necessary to remove these dust particles and avoid spreading contaminates during cleaning.


Do not sweep or mop cleanroom or lab floors. Sweeping loosens dust particles and circulates them through the air. They then settle back onto other surfaces. Traditional mopping will simply spread contaminates from one place to another.

Instead, replace brooms with high-filtration vacuum cleaners. These are available as both canisters and backpacks, provide high and low vacuuming, and they offer the flexibility to access hard-to-reach areas. Mops should be replaced with auto vacs. With these machines, you apply cleaning solution directly to the floor and the vac provides agitation to help loosen contaminates and vacuums them up.

Other surfaces (desks and counters)

Traditional cleaning for these surfaces includes sprayers and cleaning cloths. With dust, it is important to follow a few special rules to avoid spreading particles around. Always use a microfiber cleaning cloth. Additionally, only use cloths and pats of cloths that are clean. Smart towels can be folded into quadrants to provide more fresh cloth surfaces.

With dust, it’s also important to spray solution on the cloth rather than the surface to avoid sending particles airborne. Once you’ve removed the dust, you will clean the surface again by applying the solution to the surface and wiping with a clean, dry microfiber.

Flat-surface cleaning systems are also available as an alternative to sprays and cloths. These systems have a chemical injection system that delivers a cleaning solution to a microfiber wipe and then a squeegee removes excess liquid from the surface.

The biggest difference in cleaning dust versus other cleaning is that you have to avoid sending the dust airborne. With a few adjustments to your regular cleaning routine, you can effectively capture the dust first. When there is no dust present, applying a cleaning solution to the surface before wiping is still recommended.

If you have questions about cleanroom cleaning, contact Gerbig Engineering Company. We provide cleanroom certification and validation as well as construction. Our thirty years of experience will ensure that you have what you need to remain compliant. Contact us at 888-628-0056 or info@gerbig.com.

Can you Save Money and Energy Reducing HVAC in Cleanrooms?

One of the greatest expenses and energy drains in a cleanroom is the HVAC system. Air change rates, pressurization, temperature, and humidity are all monitored to maintain compliance for cleanroom classification. This accounts for about 80% of the energy used, and about 50% of that comes from that fans alone.

With strict guidelines on air quality and regulation, the HVAC systems are typically left to run at full power all the time. If you can reduce the amount of energy used by the HVAC or even shut the system down while the room is not in use (e.g. evenings and weekends), it would result in a significant cost and energy savings. The question is: is it possible to reduce the air change rates without compromising the microbial growth in a sterile environment?

According to research, yes, it might be possible to cut HVAC usage during periods of inactivity without compromising classification of the room.

Several experiments have been conducted to test this, yielding similar results. However, it is important to note that for your specific cleanroom, you should take this as part of your overall data collection to determine whether your own cleanroom qualifies for turndown or shutoff.

Pharmout.net published some interesting findings in the article “What’s your cleanroom costing you?” by Megan Rutherford. You can read the full details here. To summarize, the experiment took place in an empty Grade C cleanroom that was serviced by an airlock, both with terminal HEPA filtration.

As stated in the article, “A single air handling unit supplied the cleanroom and airlock, providing the cleanroom with up to 45 air changes per hour (AC/H). The system was balanced to provide 15 Pascals positive pressure to the airlock and 30 Pascals positive pressure to the cleanroom, relative to atmospheric pressure.”

What the study concluded was that while there was an increase in non-viable particles during low air change rates, the increase was not significant enough to change classification.

When the air change rate was stopped completely, this experiment found that classification was lost in about twenty minutes. However, depending on the cleanroom, you may be able to shut your system down completely on the weekends according to this major study.

The potential to cut energy usage and accompanying costs by limiting your HVAC system is a game-changer for a lot of companies. The end result is definitely worth your time and resources to find out if this is a possibility for your facility.

For questions or services regarding cleanroom certification or validation, contact Gerbig Engineering Company. We’ve been in this industry for thirty years. 888-628-0056; info@gerbig.com.

A Commonly and Dangerously Ignored Cleanroom Rule

If you work in a cleanroom, you know it is imperative to follow protocol. To keep contaminates out and protect yourself from toxic substances, you likely use a variety of protective wear like gowns and gloves when you work. Even though gloves provide an excellent barrier between you and what you touch, it is important to take an extra step in safety. Are you washing your hands before and after wearing gloves?

If you’re not, you need to start immediately, and here is why.

Latex gloves are not 100% impenetrable. There is a chance that contaminates from your hands can break the glove barrier. You need clean hands before you even put the gloves on to protect the controlled environment.

Glove residue can break down your tolerance to irritants. Gloves often contain materials that can cause allergies. The allergens rub off on your skin, and if left there, they will gradually increase your sensitivity to them. As a result, you could develop an allergy to the gloves. Hand sanitizer does not remove the substance – you need to use water and soap to remove it completely.

Gloved hands are perfect conditions for bacterial growth. This is a no-brainer; hands inside of gloves are warm and moist. You absolutely need to clean your hands after bacteria have had some time to breed there.

Removing gloves can have a “back spray” effect. When you take your gloves off, it is possible for fluids and/or germs to be snapped back onto your hands, carried with you everywhere until you wash or sanitize them.

For the safety of yourself, your materials, and your colleagues, it is critical that you wash your hands both before and after wearing gloves. If you have any questions about validation or certification of your cleanroom, contact Gerbig Engineering Company. We offer these services along with cleanroom construction. Call us at 888-628-0056 or email info@gerbig.com.

3 Ways to Sterilize Cleanroom Apparel

Sterility is a major part of every cleanroom, be it the equipment, the tools, the product, or the structure. In aseptic cleanrooms, the garments must also be sterile. Most companies require all components in an aseptic cleanroom – including garments – to be terminally sterilized to 10-6SAL.  There are three methods of achieving this: autoclaving, ethylene oxide (EtO), and ionizing radiation (gamma or electron beam.)


1. Steam Autoclaving

As the name suggests, sterility is attained in this method using steam and pressure. The garment is wrapped in a vapor-permeable bag and placed under a high temperature. The steam carries heat to every surface of the garment. So long as the object in the autoclave isn’t heat, pressure, or moisture-sensitive, this method is reasonably efficient and convenient. However, it typically shrinks garments up to two sizes. Aside from the obvious problem here, it degrades the material more quickly. Wrinkles also set in, making the garments unsightly.

2. EtO

This is a gas that kills microorganisms, and this sterilization method was used widely for years. It works by using a vacuum chamber to evacuate the air from wrapped objects and replace it with EtO. After sterilization, the gas is evacuated and air replaced. The greatest downside to this is EtO’s dangerous effects on humans. Items sterilized with this method had to be quarantined up to two weeks while the EtO dropped to a safe level. For this reason, extra garments need to be on hand to use while other garments are outgassing.

While both methods have their upsides, neither is considered the most advantageous given the culture and needs of today’s cleanroom. This brings us to the third, most preferred method of garment sterilization…

3. Ionizing Radiation

This includes two forms, though gamma irradiation is the only one being successfully used in cleanrooms. The electromagnetic radiation of gamma rays has great penetrating power, like an x-ray, but with a shorter wavelength. Sterilization with these rays occurs after the garments have been laundered and packaged. Before gamma irradiation, however, you must follow validation protocol to determine the dosage required to obtain the desired sterility. Since this kind of radiation is destructive, it’s important to use the lowest possible dose, which may be lower than the 25 kilograys we know are sufficient. This will help extend the garment’s life significantly.

Liability also plays a role in using the lowest possible dosage. Garment service providers undergo extremely rigorous customer audits because if the process drifts out of control or the dose has not been set properly, it can put a person’s life at risk. Therefore, the calculated sterilization dose for gamma irradiation will be included in the customer specifications for the product.


When it comes to cleanrooms, every aspect of sterilization and sanitation affects compliance and validation. Gerbig Cleanrooms knows how vital every detail is the overall process. If you need cleanroom validation or certification, or if you need cleanroom construction, reach out to us. We know what you need to achieve and maintain success: 888-628-0056; info@gerbig.com.

Certifying your Cleanroom

certification_1As anyone who does or will operate a cleanroom probably knows, that room and all of its pieces have to meet a specific set of class standards. Certification is a major part of compliance, and all cleanrooms need it done. What exactly does that mean, though?

Basically, cleanroom certification is a pass/fail test based on the standards set forth by The National Environmental Balancing Bureau (NEBB). The organization’s Procedural Standards for Certified Testing of Cleanrooms constitutes a “uniform and systematic set of criteria for the performance of cleanroom testing and certification.” A true cleanroom certification refers to the ISO 14644-1 classification test. Put most simply, its documents are concerned with airborne particle contamination within the cleanroom. Passing the test means that the airborne particles were within the set limit for the class.

NEBB’s manual contains the minimum requirements to follow for testing and certification, though. Cleanrooms not only have to remain compliant with their class standards, they also have to meet customer quality specifications. For this reason, the pass/fail criteria for each entity’s certification will be different. Certifiers will base test protocols on customer specifications.

Cleanroom Testing Categories

Cleanroom certification is ongoing. A certifier will play a role both during and after construction of the cleanroom to ensure it is compliant after it’s built. Routine certification is also necessary. There are three categories for cleanroom testing:

    • As Built – this is a newly constructed and unoccupied space
    • At Rest – this facility is already functional but unoccupied with processes shut down
    • Operational – just as it sounds, this test is performed with people, processes, and tools fully functioning

Primary Cleanroom Tests

Primary cleanroom tests will include:

    • ISO 14644-1 particle counts
    • Room pressure differentials
    • HEPA filter velocity/volume
    • Air changes per hour calculation
    • HEPA filter integrity test

Additional Cleanroom Tests

    • Temperature and humidity uniformity
    • Particle recovery
    • Airflow visualization smoke test
    • Light levels
    • Sound levels
    • Static electricity evaluation/dissipation testing
    • Laminarity

Cleanroom Environmental Monitoring

There is also environmental monitoring, which includes:

    • Airborne viable organisms
    • Surface viable organisms
    • Airborne particle counts
    • Room temperature and humidity
    • Room pressure

Experts recommend finding a qualified professional rather than try to accomplish it in-house. The equipment is expensive, and there is a lot of it. Additionally, individuals need to be qualified to use the equipment. It is not cost-effective to do certification yourself.

Cleanroom Testing: Frequency

Your certification schedule will depend on your cleanroom class. You may need monthly, annual, or biennial checks. No matter the case, it’s important to stay up to date to avoid costly problems later.

Gerbig Cleanrooms provides expert certification services for cleanrooms. For information on these services, visit this page. Feel free to contact us by phone: 888-628-0056 or email: info@gerbig.com.

Proper Monitoring of the Cleanroom Environment: Reminders

Softwall-Gownroom.jpgCleanrooms have to meet all relevant regulatory requirements that are mandated for the products being manufactured. These are agencies like the Institute of Environmental Sciences and Technology (IEST) and the International Organization for Standardization (ISO).

In order to ensure continued compliance, manufacturers need to understand what environmental factors cause contaminates, and they need the proper equipment to test for them. Here are a few reminders for your cleanroom plan.

First and foremost, remember that personnel produce the most contaminates in a controlled environment. In addition to covering people with proper garments, keep in mind:

  • Personnel should practice good personal hygiene
  • If anyone has a skin or respiratory condition, he or she should not work in the cleanroom until it clears up
  • The risk of human flora contamination increases when people perspire, so ensure that the temperature is not too hot
  • Shivering releases microbes into the air, so the temperature can also not be too cold


To ensure that surfaces meet sterility requirements, they need to be tested for environmental flora. There are two methods to accomplish this:

  • Contact plates. These are used on flat surfaces. The media filling the plates creates a dome. The surface of the media is pressed against the surface being tested. The plates are incubated, and any colonies present are counted.
  • Swabbing. Swabs can easily reach nooks, crevices, and other irregular surfaces. They are typically made of cotton, synthetics, or calcium alginate materials. The sterile swab is moistened with a non-nutritive medium and swiped in several directions over the test area. The swab is placed in a rinse solution and then agitated. The collection medium is then tested for its microorganisms.


Proper cleaning materials are also necessary to maintain an environment that meets all regulatory standards. Be sure that you have chosen cleaning supplies that work with the class of your cleanroom. Some supplies include:

  • Mops and buckets
  • Vacuum cleaners
  • Wipes
  • Brooms
  • Sponges
  • Squeegees
  • Disinfectants
  • Cleansers
  • Shoe cleaners


Once a cleanroom is built, it still needs to be maintained to ensure that manufactured materials are not compromised. It is the manufacturer’s responsibility to monitor the cleanroom environment and provide proper training for workers.

Need certification or validation for your cleanroom? Gerbig Cleanrooms does both.  Contact us today.

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