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.

Cleaning Cleanroom Floors

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.

Cleaning Other Cleanroom 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 the 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 it 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 Cleanrooms. 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, some say you may be able to shut your system down completely on the weekends.

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.

Chemicals to Avoid when Cleaning Cleanrooms

When choosing your cleaning solvents, ensure you’re not using solutions with either of these agents.

It should go without saying that keeping a cleanroom and cleanroom components clean is a top priority for any industry. The obstacle is that if you can’t physically clean surfaces, which is the most fastidious yet successful method, you have to choose chemicals, all of which leave behind some sort of residue. The key, then, is to choose a chemical that leaves the “right” kind of residue behind.

In looking at your many options, there are chemicals that you should certainly avoid. MaryBeth DiDonna wrote an article for Controlled Environments, “Choosing Your Cleaning Chemicals,” that offers guidance on this. She includes the expertise of Dr. Robert Baier, head of the biomaterials program at the University of Buffalo, and Ed and Barbara Kanegsberg of BFK Solutions in Pacific Palisades, CA.

Baier warns against silicones because they’re strong surface-active materials. He’s quoted in the article: “If you have a small contaminant in one corner of a table, by the next week the entire table will be covered [along with] anything on it. It will change the surface properties of a material like silicon or germanium or anything else you may be working on. In, say, an integrated circuit fabrication facility — everything will be siliconized and nearly impossible to be removed.”

The other caution that experts mention in the article is ultrapure water.

Ed Kanegsberg explains that this level of purity acts both as a strong base and strong acid simultaneously, looking to extract ions wherever possible. Barbara Kanegsberg explains where ultrapure water finds the ions:

“In part from the thing that you’re trying to wash or rinse, whatever you’re trying to do. That doesn’t mean that we should be using impure water, but it’s a matter of being mindful of what the chemical is. And water in itself, depending on the situation, can be a rather harsh chemical in terms of the quality of the surface.”

So when you’re doing the research to find the best chemical solvents for your facility, heed the warnings to avoid silicones and ultrapure water. When it’s time for cleanroom validation or certification, turn to a company with the right experience and knowhow. Gerbig Engineering Company has been a trusted expert on cleanrooms for thirty years. We offer many services for cleanroom validation, certification, and construction. Contact us at 888-628-0056 or info@gerbig.com.

Why More Cleanroom Managers are Outsourcing Cleaning

Who cleans your cleanroom? If you’re in the majority, your cleanroom workers are also taking on detailed cleaning responsibilities. Controlled Environments recently published the latest “Cleanroom Trends and Salary Survey,” and the cleaning trends have changed since last year. While the trend to use cleanroom workers as the primary cleaning staff rose slightly, from 42% to 46.3%, the other two categories saw significant change. People using an in-house cleaning staff dropped from 33% to 20.7%. Responders who say they outsource cleaning rose from 24% to 32.9%.

What’s causing fewer people to employ an in-house cleaning staff and more people to hire an outside cleaning company?

The most obvious reason a cleanroom facility wouldn’t hire an outside cleaning company is the expense. So if outsourcing is becoming more popular, the value of this service is probably becoming more evident. Let’s look at some of the costs a professional cleaning company helps cleanroom managers avoid.

  • Equipment and cleaning products. Any cleanroom facility needs cleaning tools regardless of who cleans it, but routine cleaning and less-frequent major cleaning jobs require more specific instruments that can be quite an investment. They also pose additional maintenance, disposal, and replacement costs.
  • Training and compliance. Cleanroom cleaning is so specific that there are protocols right down to the direction in which you can wipe a surface. Training for this job is extremely detailed, and it’s paramount that staff follows SOPs exactly or the room may not remain compliant. This, of course, would lead to even bigger problems.
  • Labor. The bigger cleaning jobs require extra staff, and arranging additional, qualified labor can be a drain on resources. Also, back-up cleaners are necessary to fill in when a primary staff member is ill or unavailable.
  • Quality of work. A cleanroom employee’s strengths and passions will lie in the actual work he or she performs in the cleanroom, not the cleaning tasks. Doubling up on duties can potentially hurt the quality of work performed during a shift and the cleaning itself.

Realistically, some cleaning jobs are going to be best handled in-house while others will make better sense to outsource. Anyone considering a change in how cleaning is handled should analyze the specific cleaning needs against the workflow to determine when and where a designated cleaning staff would most benefit the company.

When it’s time for the important cleanroom certification and/or validation, contact Gerbig Engineering Company. Cleanrooms have been our specialty for thirty years: 888-628-0056; info@gerbig.com.

Quick Checklist for Cleanroom Cleaning Costs

Here’s a checklist for your cleanroom cleaning system costs. Use this as a guideline for budgeting with your new system.

We post a lot of information about cleaning your cleanroom. It is a complex and involved aspect of compliance and safety. Things to consider vary from the cleanroom itself to the parts inside of it. You can browse some of our topics here.

One crucial aspect of any new cleaning regimen is the cost. You need to know what to anticipate as far as expenses are concerned. These will include initial one-time costs as well as ongoing. The type of system you need depends on your specific application, so exact materials and costs will vary. However, you can get an idea of what you need to budget for by using this checklist put out by Controlled Environments in “Cleaning Costs Checklist” by Mike Jones. Here is how the MicroCare Corp expert lays it out.

Capital Costs – One-Time Costs

  • • The actual cleaning system
  • • Architectural planning and site engineering
  • • Construction
  • • Insurance and freight
  • • Electrical
  • • Plumbing
  • • Ventilation
  • • Set-up of the actual system
  • • Cost of capital


  • • Will be a cost per square foot
  • • Size of the machine(s)
  • • The workspace multiplier

Throughput Calibration Factors include:

  • • The cycle time
  • • The boards per cycle and maximum boards per hour
  • • Number of operating hours required each day
  • • The stand-by hours each day

Operating Costs

  • • Water and electricity
  • • Consumables like filters
  • • Solvent –
    • • Losses
    • • Disposal
  • • Labor –
    • • Operator cost per hour
    • • Inspection and re-cleaning per hour
    • • System maintenance per hour

This checklist will get you started in understanding the costs you need to anticipate for a cleanroom cleaning system. For cleanroom validation or certification, trust Gerbig Cleanrooms. Our experts understand compliance for cleanrooms in several industries. Contact us at 888-628-0056 or info@gerbig.com.

Three Tests for Disinfectants for Cleanroom Validation

You need to control fungal contamination in your cleanroom, and you need to test the disinfectants for validation. Here are three to consider.

Controlling fungal contamination in your cleanroom requires cleaning and disinfection procedures. Your disinfectant application is a critical step that needs validation. Since many agents that are effective against vegetative fungi aren’t effective against fungal spores, it’s necessary to conduct a series of tests to demonstrate your agent’s efficacy. Here are three testing methods to consider.

  1. Suspension tests. These are especially valuable for finding how much time is needed to reduce organisms to an acceptable level. However, they don’t reveal any variations in efficacy that happen when disinfectants are applied to different surface types. The test procedure is to suspend the microorganism in an appropriate dilution of the test disinfectant. At designated time intervals, samples are removed for viable counts. The test is conducted at room temperature.
  1. Carrier tests. These are specific to hard-surface disinfection agents, and they’re performed under the conditions that match your facility’s specific application. Typical cleanroom surfaces are stainless steel, but can also include terrazzo flooring, vinyl, epoxy, and glass.
  1. Statistical comparisons. While both of the above tests are quite reliable in evaluation a disinfectant’s efficacy under lab conditions, they guarantee results in your actual cleanroom environment. To address this, you need to perform statistical comparisons of the frequency of isolation and the numbers of organisms isolated before and after a new disinfection program is implemented. Trend the environmental data over the course of a year to find seasonal variations that may cause facility or maintenance issues.

When it’s time for cleanroom validation, trust the experts at Gerbig Engineering Company. We’ve provided cleanroom validation, certification, and construction for thirty years. Contact us at 888-628-0056 or 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.

Cleaning the Components in Electronics Manufacturing

Electronic components in adverse environments require careful cleaning to remain compliant. This article explores the means of doing so.  

Thanks to no-clean fluxes and soldering pastes, the need to clean components in electronics manufacturing has decreased significantly. However, this is only the case for components used in non-critical atmospheric environments. Adverse environments, like humid or fluctuating temperatures, can erode the protective layer applied in the no-clean process. This releases ionizing substances that promote electro-migration and dendritic growth. You’ll find this in narrow spaces under components and between connections and contact surfaces. Additionally, fluxes, residues of soldering agents and adhesives, and dust need to be removed from electronic components.

In choosing a cleansing agent, you need to consider the subject material as well as the nature and quantity of the impurities to remove. Cleaning agents for electronics include solvents, water-based media containing alkaline surfactants, and water-based tenside-free solutions.

Solvent Options

Solvents for the electronics manufacturing industry contain non-halogenated hydrocarbons, modified alcohols, or hydrofluorethers (HFEs). HFEs are the alternative to chlorofluorocarbons (CFCs), which were found to have a high potential for breaking down ozone about 20 years ago. Both have similar properties, but HFEs don’t persist in the atmosphere and pose no danger to ozone. Monosolvent, bisolvent, and cosolvent systems use these solvents.

  • • Monosolvent: Using a pure HFE or azeotrope, these systems remove slight impurities like halogen compounds, particles, dust, light oils, and residue of easy-clean solvents.
  • • Bisolvent and Cosolvent: Both systems combine HFE with a low-volatility organic solvent. The solubility promoter of the organic solvent removes impurities while the HFE rinses them away. These are great for stubborn impurities like wax, adhesives, heavy oils, hot-melt glues, grease, and C-flux residues. The biggest difference between these two systems is that the solvent and rinsing agent are mixed together in a cosolvent and kept separate in a bisolvent.


Water-Based Cleaning Agents

  • • Ultrasound cleaning with water-based media offers practical solutions to electronics manufacturers. The electrical signals from the ultrasound influence the cleaning action for the cleansing agent. The lower the frequency, the more energy is released by sound waves. Cleaning tests will help you figure out the right combination of cleansing agent and ultrasound frequency.
  • • Carbon dioxide offers a nice dry alternative. Compressed carbon dioxide possesses excellent properties as a solvent on nonpolar impurities like grease and oil. With low viscosity and interfacial tension, supercritical CO2 has a strong capacity for penetrating crevices. This works well for small, drilled holes and other complex geometries. This environmentally-friendly, dry, residue-free procedure can clean complete PCBs and assemblies.
  • • The chemical, thermal, and mechanical properties of CO2 snow-jet cleaning removes surface films and particulate contamination without leaving residue. This type of cleaning can be used on contact points, in preparation for bonding processes, equipping PCBs and foil-PCBs, and manufacturing of metal-insulator semiconductors.
  • • Plasma is another medium used to clean electronics. The physical and chemical reaction during the cleaning procedure allows plasma to efficiently surface treat parts and components while cleaning away organic impurities like oils and grease and activate the surface. Depending on the application, low-pressure plasmas or inline-capable atmospheric pressure plasmas can be used.

For all water-based media, solutions will depend on your plant technology as well as the components that need cleaning. For other cleanroom solutions, like certification, validation, and modular construction, contact Gerbig Cleanrooms. Our experts understand compliance and electronic manufacturing: 888-628-0056; info@gerbig.com.

How to Control Fungus in Cleanrooms

Fungal issues are significant in controlled environments. To ensure your cleaning agent will be effective against mold and yeast, follow this series.

Fungal contamination from mold and yeast are concerns for cleanrooms in any industry. Mold issues in particular have surfaced in cold rooms, door kick plates, incubators, and cleanroom startups in addition to the cleanrooms themselves.

One of the major concerns, outside of properly testing for and catching contamination, is finding an effective disinfectant. Not all disinfectants are effective against fungal spores; you might have to use a sporicidal agent to control fungi. Another issue is that fungus will develop a resistance to products, so you need to rotate at least two different ones that are equally effective.

When selecting a disinfectant, you need to take critical steps to ensure you choose an effective agent. Here is the first:

Gather all information and data.

Before you can test products or even choose them, you need all the information necessary to make your decision. Collect all the relevant and available information from the suppliers. The information you want includes:

  • • Technical data sheets
  • • MSDS
  • • Recommended directions for use
  • • Review all available testing on substrate compatibility, stability, and microbial efficacy
  • • Ensure these tests were performed in accordance with accepted standards (AOAC, ASTM, EN)
  • • Check that the product was manufactured according to local, state, and country regulations
  • • Certificate of manufacture/analysis
  • • Audit supplier’s change control policies to ensure you’re notified of any significant changes to the product
  • • Any other information you need to compare products and make the appropriate selection

Selecting a Disinfectant for your Cleanroom

There are numerous types of fungi that can grow in your cleanroom. Selecting the right disinfectant(s) depends on several processes. In part one, we discussed the different types of relevant data you want to collect. Here we will discuss testing disinfectants for efficacy.

Many factors influence the effectiveness of the active ingredients in biocides. Some of them include:

  • • Concentration
  • • Surface type
  • • Contact time
  • • pH
  • • Organic soil
  • • Bioburden
  • • Hardness of the water
  • • Temperature

The actives used against fungal spores will perform differently depending on the factors above. It is therefore necessary to perform in-house testing. For pharmaceutical environments in particular, a series of tests are necessary. Some agents that work against vegetative fungi aren’t effective against fungal spores. Here are three methods to consider.

  1. Suspension Tests:
    These tests work to determine the time necessary to reduce an acceptable amount of organisms. However, they do not address efficacy within various surface types. The microorganism is suspended in the appropriate dilution of the test disinfectant. This should be done at room temperature at selected time intervals. After neutralizing any remaining disinfectant from the sample, viable counts can be performed.
  2. Carrier Tests:
    Here is where you will test efficacy on hard surfaces. You use a carrier made of the type of surface(s) in your cleanroom (e.g. stainless steel) to test disinfection agents. Typical cleanroom surfaces include stainless steel, terrazzo flooring, epoxy, vinyl, lexan, and glass.
  3. Statistical Comparisons:
    This is an ongoing test comparing the frequency of isolation and the number of organisms isolated before and after disinfection. It’s important to carry these tests out throughout the year. You may find seasonal variations that alert you to facility or maintenance issues.

In the end, the disinfectant application process should be validated. If you need cleanroom validation or certification, or if you have questions about these processes, contact Gerbig Cleanrooms at 888-628-0056 or info@gerbig.com.

The health and safety of our employees, customers and communities is our top priority.Read about our response to COVID-19.