ULPA vs. HEPA Filters for Cell & Gene Therapy Cleanrooms

ULPA vs. HEPA Filters for Cell & Gene Therapy Cleanrooms

In the past couple of years, cell and gene therapies have been recognized as viable forms of treatment for life-threatening conditions, leaving many healthcare professionals excited about putting more effort into researching, developing, and distributing them. But in order to do so, they need a highly controlled environment — otherwise their results aren’t guaranteed to be safe, effective, or repeatable. 

The cleanroom component that plays the most integral role in a space’s cleanliness and performance is its filtration system, which consists of either ULPA or HEPA filters. Let’s discuss the differences between these two types of filters, so you have a better idea of which one may be best suited for your cell and gene therapy cleanroom. 

ULPA vs. HEPA Filters: What’s the Difference?

ULPA and HEPA filters both do great work catching tiny, airborne particles like bacteria, pollutants, and dust. They’re manufactured with similar technologies, but feature some differences in their filtration efficiency, airflow capacity, price, and lifespan. 

ULPA Filters

ULPA filter stands for Ultra-Low Particulate Air filter (ULPA). These filters are highly efficient and capable of meeting even the most stringent cleanliness requirements. Below are some of their standard specifications (which may or may not vary, depending on the exact size or brand of system you choose):  

  • Filtration efficiency: 99.999% efficient at removing particles 0.12μm or larger 
  • Airflow capacity: 20-50% lower than HEPA filters, due to denser filter
  • Price: generally more expensive than HEPA filters, due to higher filtration efficiency
  • Lifespan: estimated 5-8 years, depending on the surrounding environment

HEPA Filters

HEPA filter stands for High-Efficiency Particulate Air (HEPA). These filters are the most commonly used in cleanroom applications due to their quality filtration, cost-effectiveness, and longevity. Below are some of their standard specifications (which may or may not vary, depending on the exact size or brand of system you choose):  

  • Filtration efficiency: 99.999% efficient at removing particles 0.3μm or larger 
  • Airflow capacity: 20-50% higher than ULPA filters, due to less dense filter
  • Price: generally more affordable than ULPA filters, due to lower filtration efficiency
  • Lifespan: estimated 7-10 years, depending on the surrounding environment

Filtration Considerations for Cell & Gene Therapy Cleanrooms

Cell and gene therapies are practices that require a high level of control. In order to fulfill their purpose and work effectively to treat life-threatening diseases, there can be no disruption in their production process — which is why they’re usually concerned about removing smaller airborne particles between .1, .3, and .5 microns. Other cleanroom applications with less stringent requirements are typically only concerned about .5, 1, and 5 microns. This is the most important factor in determining which type of filter is best for cell and gene therapy cleanrooms. 

This also implies that most cell and gene therapy cleanrooms must meet stringent ISO standards, which are usually between ISO Class 5-7, but can be higher or lower depending on the application. For ISO 5, this means that they must have at least 240 air changes per hour, 35-70% ceiling coverage, 40-80 feet per minute of air velocity, and no more than 10,200 particles 0.3μm or larger in a cubic meter. The requirements are a little looser for ISO 7, which requires at least 60 air changes per hour, 15-20% ceiling coverage, 10-15 feet per minute of air velocity, and no more than 1,020,000 particles 0.3μm or larger in a cubic meter.

ULPA vs. HEPA Filters for Cell & Gene Therapy Cleanrooms

So, which type of filter is right for your cell and gene therapy cleanroom? ULPA or HEPA? 

It depends on what specific tasks you’re hoping to accomplish within your cleanroom. Currently, in the world of cell and gene therapy, there are four main types of therapies:

  • Cell therapy
  • Gene-modified therapy
  • Gene therapy
  • Tissue-engineered products

Each of these therapies require a number of different sub-processes, which all require a different level of control. It’s best to determine which ISO standard your cleanroom needs to meet first and what size airborne particulates can be detrimental to your process, then choose your type of filter based on that.

But from a broad perspective, ULPA filters are generally recommended for cell and gene therapy processes, since they offer more stringent control over smaller airborne particles. HEPA filters can offer enough control for some cell and gene therapy applications, but aren’t the most commonly recommended. 

Cell and gene therapy are two fairly new, but steadily growing practices in the medical field. If you’re hoping to install a cell and gene therapy cleanroom in your facility, it’s important that you get the details right — and for that, you can trust Angstrom Technology. Our experts have experience designing, building, and servicing cell and gene therapy cleanrooms (check out our latest project!) across the globe, and we’d be happy to create a solution that meets your specific needs. Contact us online to get started. 

What Is a Cell and Gene Therapy Cleanroom?

What Is a Cell and Gene Therapy Cleanroom?

Cell and gene therapy are two fairly new practices within the medical field. However, they’ve recently become recognized as viable forms of treatment for various life-threatening conditions. As their popularity increases among healthcare providers worldwide, there’s been a greater push to research, develop and distribute these treatments — and in order to do that safely and effectively, cleanrooms are critical. 

Here’s a little more information about what cell and gene therapy cleanrooms are, as well as some considerations you may make before designing one of your own. 

What Is Cell and Gene Therapy? 

Cell and gene therapy are both forms of regenerative medicine. They involve extracting cells, protein, and/or genetic material (DNA) from a patient or donor, then altering the sample to provide highly personalized treatment, then reinjecting the sample into the patient. 

Although these are relatively new therapies, many healthcare providers are hopeful that they’ll offer longer-lasting effects than existing methods. They’ve also been found to be safer, more targeted, and less invasive. For patients with serious illnesses, the research and development of these therapies could be a matter of life and death.

Design Considerations for a Cell and Gene Therapy Cleanroom

Just like any other modular cleanroom, cell and gene therapy cleanrooms can be constructed as free-standing structures or supported by the existing building structure. However, the work done within them requires more complex production processes than previous medicinal applications. Things like cellular engineering, genetic engineering, growth, and purification all must be done in an even more controlled environment, so that results are sure to be safe, effective, and repeatable. 

That said, cell and gene therapy cleanrooms require some unique cleanroom design considerations, including (but not limited to) the ones listed below:

ISO Classification for Cell and Gene Therapy Cleanrooms

Most cell and gene therapy cleanrooms must meet stringent ISO standards, usually between ISO Class 5-7. For ISO 5 classification, this means that they must have at least 240 air changes per hour, 35-70% ceiling coverage, and to ensure no more than 3,520 particles 0.5μm or larger allowed per cubic meter. 

Additional Equipment and Technology for Cell and Gene Therapy Cleanrooms

Each cleanroom industry and application requires a variety of unique pieces of equipment and technology. Here are a few on the list that are often required for cell and gene therapy cleanrooms:

  • Gowning rooms
  • Hazardous material storage
  • Laminar flow hoods, biosafety cabinets, fume hoods
  • HEPA and ULPA filtration systems
  • Standard, flow-through, LED strips, and other lighting options

Angstrom Technology’s Latest Cell and Gene Therapy Cleanroom Project

Want to see an example of a recent cell and gene therapy cleanroom project? Here’s some information on one that our partners at Connect 2 Cleanrooms built in 2021!

This project consisted of a full cleanroom suite that was housed within a two-story building with 33 internal rooms. It featured high levels of filtration and cleanliness, along with a variety of unique features, including:

  • ISO 5 classification (equivalent to EU GMP Grade B)
  • HEPA filtration 
  • Fire-rated active pass-through chambers
  • Vaporized hydrogen peroxide (VHP) cabinets
  • Integrated medical gas systems
  • Cryostorage

Read more about this project on our Cell & Gene Therapy Cleanroom Suite project page. 

Cell and gene therapy is a fast-growing industry! If you’re looking to install a cleanroom for your cell and gene therapy application, reach out to our team at Angstrom Technology. Our cleanroom design experts are happy to help you create the controlled space you need to continue researching, developing, and distributing these life-saving treatments. 

Modular Cleanroom FAQs

Modular Cleanroom FAQs

Need more details on modular cleanrooms? We’ve got you covered. Below, we’ve answered 10 of the most frequently asked questions we receive about modular cleanrooms here at Angstrom Technology. 

1. What Is a Modular Cleanroom?

A modular cleanroom is a cleanroom built of prefabricated components that are quickly and easily assembled to meet your specifications on-site. The prefabricated components are manufactured off-site, then delivered ready for installation, which allows for controlled conditions and improved quality and precision. 

Modular cleanrooms are able to meet any cleanliness and classification standards your application requires. They’re also easily reconfigured based on your facility’s changing needs.

2. Do I Need a Modular Cleanroom?

Modular cleanrooms are used in a variety of industries, for a variety of applications. If you need a space that is clean, safe, and virtually contaminant-free in order to successfully execute any of your processes, you’ll probably want to consider investing in one. It will keep your people, products, and property safe, so you can continue to run a profitable business. 

To provide some examples, here are a few of the industries that we commonly work with here at Angstrom Technology: aerospace & defense, agriculture, automotive, biotech, environmental testing, medical (hospital, medical device, research, marijuana), microbiology, pharmaceutical manufacturing, plastic injection molding, semiconductor. 

3. How Long Does a Modular Cleanroom Take to Design, Build, and Install?

Although the modular cleanroom design, build, and installation process can vary based on the size and complexity of your design, the process is usually very quick — especially when you compare it to that of traditionally built cleanrooms

Most often, framing, drywall, and painting are the worst trades in terms of efficiency. But with prefabricated modular construction systems, those are replaced with a high level of efficiency. In fact, prefabricated panels can result in a 25-75% schedule reduction compared to traditional construction.

At the start of the process, it may take a couple of weeks to consult with a designer about your application’s needs and create a design. After that, you’ll wait for a brief delivery period (6-8 weeks with Angstrom’s industry-setting standard). Once all components are delivered, your modular cleanroom can be installed in just a few weeks, depending on the size. 

4. How Much Does a Modular Cleanroom Cost?

The cost of a modular cleanroom is highly competitive to that of a traditionally constructed cleanroom — primarily due to the fast and simple design, build, and installation process. In addition, there’s a tremendous reduction in the costs of waste, unused materials, and lost items that are associated with traditional construction.

That said, modular cleanroom costs can vary tremendously from project to project. In most cases, the cost of a modular cleanroom is based on the following factors:

5. What Are the Benefits of Modular Cleanrooms?

Modular cleanrooms bring the same benefits as traditionally built cleanrooms — and more! In fact, when compared to their traditional counterparts, modular cleanrooms are generally:

  • Quicker and easier to install, ensuring that you’re able to resume regular operations in no time. 
  • More adaptable to your facility’s changing needs, as modular cleanrooms can be constructed and/or reconfigured to fit any space, even within an existing building. 
  • More affordable, due to prefabricated components and a speedy installation process. 

6. What Should I Expect From the Modular Cleanroom Installation Process?

As mentioned in Question #2 above, the modular cleanroom installation process is quick — and, if you’d like to, you can save on labor costs and do it yourself! At Angstrom Technology, we’ll send you a detailed list of installation instructions to follow. 

However, if you’re worried about the technical details, we’re also happy to complete the installation process for you. We employ an experienced team of modular cleanroom construction specialists who will install your room for you, leaving you with minimal disruption to your workdays. We’ll get things done and pay close attention to the details so you don’t have to. 

7. How Do I Know Which Type of Cleanroom I Need?

There are three common types of cleanrooms: HardWall, SoftWall, and RigidWall. The type you need depends on what you plan to use it for. 

  • HardWall cleanrooms are made of an aluminum frame and prefabricated solid panels. They suit most applications but are especially helpful for those with stringent cleanroom classification requirements. 
  • SoftWall cleanrooms are made of an aluminum frame and vinyl curtains around the perimeter. They’re capable of meeting most cleanroom classifications, but not the most stringent — especially when it comes to temperature and humidity control. 
  • RigidWall cleanrooms are made of an aluminum frame and clear, acrylic panels — giving them the durability and security of a HardWall cleanroom, plus the visibility of a SoftWall cleanroom. 

If you’re still unsure which type of cleanroom may best suit your application, it’s best to contact a cleanroom expert. They’ll listen to your needs and propose a solution that is sure to meet them. 

8. How Do I Know Which Cleanroom Classification I Need?

Your cleanroom is required to meet a certain ISO classification. ISO classification determines the degree of cleanliness, which is defined by the maximum amount of contamination allowed, by particle count and size. More stringent ISO classifications (i.e. Class 1-5) require higher filtration and air change rates. Less stringent ISO classifications (i.e. Class 6-9) are a little more lenient, working themselves all the way down to normal room air. 

For example, pharmaceutical cleanrooms require a stringent ISO classification because it’s a high priority to ensure products are kept safe so that, in turn, their consumers are kept safe. When even the smallest particle could affect the performance of a drug, there is no room for contamination or error. 

9. How Does Cleanroom Classification Affect Cost?

Generally, the more stringent your cleanroom classification, the more you’ll pay. This is because more stringent classifications require more filtration — and in order to achieve that, your cleanroom will need to accommodate more fan filter units and additional features like gowning rooms, air showers, etc.

10. Will My Modular Cleanroom Need Any Additional Features? 

Some modular cleanrooms just require the most basic components. However, modular cleanrooms that need to meet stringent classification requirements may require additional features and technologies to successfully avoid contamination. Things like airlocks, air showers, pass-through chambers, and gowning rooms are important considerations to keep sensitive applications free of harm. 

Have more questions about modular cleanrooms? Give the experts at Angstrom Technology a call! We’d be happy to walk through your specific needs and help to design, build, and install the best modular cleanroom for your facility.

Understanding the Value of Modular Cleanrooms

Understanding the Value of Modular Cleanrooms

At Angstrom Technology, we like to take a step back every once in a while, taking the time to acknowledge and appreciate the impact of our work in various industries. It helps us put our work into perspective, and it motivates us to deliver excellence each and every day.

As we’ve reflected throughout the past years, we’ve always been astonished at how much innovation happens within modular cleanrooms. These quickly built, easily modified, heavily treated chambers truly make groundbreaking work possible. As a resource that helps scientists, and engineers test, manufacture, and package products safely, cleanrooms bring tremendous value not only to the workforce, but to society as a whole. 

In this article, we’ll explore some amazing ways that various industries have used modular cleanroom technology to trailblaze a path of innovation.

The Value Modular Cleanrooms Bring to Various Industrial Applications

Modular cleanrooms have proven themselves to be beneficial for a number of applications, in a number of industries. Some of history’s most important inventions required cleanrooms’ quality control, and some of the future’s best and brightest innovations are being tested in them today. Below, let’s discuss some common industries that use cleanrooms, and what important things they’re using them for. 


Aerospace cleanrooms are crucial for the development of aircraft and spacecraft hardware, fine electronics, engine components, and more. In order to manufacture, assemble, and test those components, the aerospace industry needs a high level of control over the cleanroom environment — usually meeting an ISO Class 7 requirement, at minimum.

Each day, aerospace engineers are working hard to develop technologies that help us continue our journey of exploring the unknown. Modular cleanrooms give them the space they need to do that revolutionary work. 


Semiconductor cleanrooms prevent particles from contaminating certain parts of nanotechnology — like semiconductors and microchips — that allow us to operate phones and computers more safely and efficiently. When even the smallest bit of contamination can lead to serious product issues and failures, a stringent modular cleanroom environment of ISO Class 5 or lower is necessary. 

Our world is reliant on constant technological innovations in order to stay connected, do business, and maintain a quality lifestyle. Modular cleanrooms will always provide a space to make those technological advances happen.

University Labs and Research Facilities

University labs and research facilities encompass a variety of applications, from medical research, to forensic science, to hazardous chemicals. Additionally, the university setting requires that spaces are able to be reassigned and restructured as student, research, and funding needs change throughout the years. Therefore, the versatility of quickly built, easily modified modular cleanrooms is extremely valuable here. 

Universities host some of the most advanced, highly recognized research facilities. Students and faculty are working with state-of-the-art technology to solve some of their industry’s most perplexing problems. A modular cleanroom can provide a controlled environment to foster that learning, no matter what the specific application may be. 


In regards to the military, weapons manufacturing is a critical component in upholding national security and protecting American citizens. Due to the deadly nature of the products and volatile compounds used in this industry, a controlled cleanroom environment is crucial in maintaining the safety of information, products, and personnel. 

Weapons manufacturing is, and always will be, dangerous. However, it plays a key role in protecting our nation’s infrastructure from devastating threats. Modular cleanrooms can help lessen the risk and bolster the production. 

Angstrom Technology can design a modular cleanroom to meet all your requirements and design considerations. If you’re interested in designing and installing one for your facility, speak with one of our design engineers to get started.

Cleanroom Classification FAQs

Cleanroom Classification FAQs

Cleanroom classification is often one of the most confusing parts of designing and building a cleanroom. However, it’s also one of the most essential parts, so it’s important that you understand all the relevant information.  If you’re installing a cleanroom for the first time, you probably understand that every type of cleanroom requires a different classification, but you’re bound to have a number of other questions — and that’s okay! We’re here to help. Below, we’ll provide answers to some of the most common cleanroom classification questions we receive.

1. What are cleanroom classifications?

Cleanroom classifications regulate a cleanroom’s degree of cleanliness. They’re defined by the allowed amount of contamination, by particle count and size, as well as the air change rates necessary to maintain that.  There are a variety of classification types that regulate cleanroom cleanliness, but the main system was developed by the International Standards Organization (ISO). ISO classifications apply to all cleanroom industries and applications, and range from Class 1 (most clean) to Class 9 (least clean, regular room air). 

2. What cleanroom classification do I need?

It depends on your industry and application. The requirements will vary depending on the size of particles that need to be filtered, the sources of contamination present, and the recommended air change rates. If your industry is regulated by the government, you can check applicable regulations to see what cleanroom classification is required. If you work in a sector that isn’t regulated by the government and that doesn’t have an industry default, you’ll need to determine the appropriate classification for yourself, based on your application’s needs.  Below, we’ll explore recommended cleanroom classifications for a few popular industries. For a full list of industries and their cleanrooms classifications, visit our cleanroom industries page

What cleanroom classification is best for aerospace applications?

Aerospace applications require control over mechanical, thermal, chemical, and electrical properties within the cleanroom. In most cases, their cleanrooms need to meet at least a Class 7 ISO classification. However, in highly sensitive applications like spacecraft hardware, fine electronic, and optical device development, a more stringent classification is necessary.

What cleanroom classification is best for manufacturing applications?

There are various types of manufacturing processes, all with different needs in terms of humidity, contamination, pressure, and temperature control. However, most manufacturing cleanrooms tend to be required to meet ISO Classes 7 or 8. 

What cleanroom classification is best for medical applications? 

There are a few sub-categories that fall under the broad category of medical cleanrooms, including medical research, medical device, and pharmaceutical cleanrooms. All of these cleanrooms have some of the most stringent classifications in order to protect the safety of operators and consumers. 

  • Medical research: ISO Class 5-7
  • Medical device: ISO Class 5-8
  • Pharmaceutical: ISO Class 5

What cleanroom classification is best for semiconductor applications?

Contamination is a large source of production issues and product failures in semiconductors and microelectronics, so it’s critical that the cleanrooms they’re manufactured and packaged in are filtered appropriately. In most cases, semiconductor cleanrooms will hold ISO Class 4-6 requirements. 

3. How often should I test my cleanroom to see if it’s meeting classification requirements?

ISO requires that air pressure difference and airflow be tested every 12 months for all classifications. For ISO Classes 6-9, particle tests must also be performed every 12 months, but for ISO Classes 1-5, those particle tests must be performed every six months.  The following tests are recommended for all ISO Classes, every 24 months:

  • Installed filter leakage
  • Containment filter leakage
  • Recovery
  • Airflow visualization

4. How often do I need to have my cleanroom inspected?

That depends on your cleanroom classification. The more stringent the classification, the more regular the inspections. Inspections may coincide with compliance testing, so they could occur every 6-12 months, depending on your specific requirements. 

5. How does cleanroom classification affect my budget?

In general, the more stringent your cleanroom classification, the greater the cost. Strict classifications require more air, energy, advanced technology, and equipment, so their prices reflect that. For a more detailed breakdown of the costs, you can check out our blog, “How Does Cleanroom Classification Affect Your Cleanroom Budget?”

6. Can I redesign my cleanroom to fit a different classification?

Yes. Every facility’s needs change over time. A cleanroom from Angstrom Technology can change right along with them. All of our cleanrooms are “backward compatible,” meaning their size can expand or decrease and their fan filter units can be added or removed to keep up with any changes in cleanroom classification requirements.  Have any questions about your cleanroom classification and how to reach it? Contact the experts at Angstrom Technology! We’re happy to walk through your specific requirements and help design and build the best cleanroom for your facility and application.

How to Choose a Fan Filter Unit for your Cleanroom

How to Choose a Fan Filter Unit for your Cleanroom

In order to ensure your facility is meeting required cleanliness standards, fan filter units (FFU) are a critical component of your cleanroom design. Let’s explore more about fan filter units: how they work, what types there are, and how to choose the right one for your cleanroom.

What Is a Fan Filter Unit?

A fan filter unit is an independent filtration system mounted in a modular cleanroom ceiling grid that is used in conjunction with an air handling unit or HVAC system. It contains a fan, a pre-filter, and a filter (either HEPA or ULPA). In most cleanrooms, multiple fan filter units are installed in the cleanroom ceiling grid and are designed to provide a consistently treated workspace, minimizing dead zones.

Individual fan filter units can be added and subtracted according to the size and necessary ISO Class regulations. In general, the bigger your cleanroom, and the more stringent your ISO Class, the more fan filter units your cleanroom will likely need.

How Does a Fan Filter Unit Work?

Fan filter units work by continuously pushing clean, filtered air into your cleanroom. Air travels through a pre-filter, through the fan, and then through the HEPA or ULPA filter that treats and filters out airborne particles prior to entering your cleanroom.

When Do You Use a Fan Filter Unit for a Cleanroom?

Fan filter units provide a number of advantages over traditional air handling units. Here are a few reasons you may consider using fan filter units for your cleanroom:

  • Easy to install – Because they are mounted in the cleanroom ceiling grid, fan filter units are easy to install and are easily accessible from within the cleanroom.2
  • Easy to modify – As your facility grows and changes, your filtration system can too. Fan filter units can easily be added into the ceiling grid if you have to meet increased cleanliness requirements in the future.
  • Cost-effective – Fan filter units are generally less expensive than a completely new air system, both in terms of production cost and installation cost.

Types of Fan Filter Units: PSC vs. ECM

While all fan filter units function in generally the same way, there are two types of motors that commonly power a cleanroom FFU: permanent split capacitors (PSC) and electronically commutated motors (ECM). Each motor functions a little differently, providing distinct advantages depending on which option you choose. PSC motors operate at one consistent speed, while ECM motors have a variable speed drive and can adjust speed based on application requirements.

PSC vs. ECM: Which Fan Filter Unit is Right for Your Cleanroom?

Both of these are reliable options, guaranteed to provide the filtration your cleanroom needs. However, ECM units are often the best choice to help you meet your cleanroom goals and maximize treated space.

The Benefits of an ECM Fan Filter Unit

ECM fan filter units are known to be air-treating powerhouses for a range of applications — especially if those applications require varying filtration speeds. Its variable speed drive includes numerous benefits, including:

  • Smooth operation in inconsistent conditions
  • Great durability for big, long-haul projects
  • Energy-saving technology to help you reduce utility costs

Looking for a cleanroom that incorporates high performance filter fan units? Angstrom Technology can design a cleanroom to accommodate any equipment for your application. Contact us today to get started.