Author Archives: Liberty Industries

  1. What Is an Air Shower?

    Leave a Comment

    Air showers are an essential part of any cleanroom operation, addressing the biggest potential containment breach at its source. These chambers or tunnels are a key preventative measure that any cleanroom manager should consider. In this blog, you’ll learn more about air showers and why they’re integral to critical cleanroom applications across many industries.

    How Do Air Showers Work?

    Air showers are tunnels or chambers containing air jets that blow off personnel entering or departing a cleanroom. The pressured jet nozzle air streams drive dirt and dust particles away from the people or objects in the chamber. It then filters out contaminants and redirects them out of the chamber.

    Air showers are positioned at the entrances and exits to cleanrooms or other highly controlled environments. As entrances and exits can be the biggest source of containment breach or contamination, having air showers as an extra layer of security for products and workers is a worthy investment.

    A one-person air shower has two doors that cannot open simultaneously. When the employee enters the air shower chamber from the outside, both doors lock, and then the air jets blow air in high-velocity streams for 4 to 8 seconds. This process blows potential contaminants to a low-pressure section of the chamber. After waiting another 2 to 4 seconds for the room to be cleared of contaminants, the second door leading to the cleanroom will be unlocked and allow the employee to enter.

    Why Air Showers for Cleanrooms

    Cleanroom entrances and the people entering through them pose the greatest risk of contamination and must be managed accordingly. Air showers reduce pollutants that stick onto personnel and equipment despite prior gowning or disinfection procedures. Entrances and pass-throughs with an air shower act as a barrier between critical and non-critical regions.

    By dislodging particulates before they get into the cleanroom, air showers also minimize particle accumulation to reduce cleanroom maintenance needs. They help to decrease energy consumption because HEPA filters do not have to work so hard. In fact, the filters last considerably longer when personnel utilize air showers.

    Applications of Air Showers

    When utilized correctly, an air shower can eliminate the majority of harmful contaminants before they even enter your cleanroom, ensuring your product stays safe and uncontaminated. Here are examples of where air showers can be applied.

    • Aerospace Cleanrooms: The aerospace industry consists of complex aircraft that require failproof components made to the highest standards. Excess particles may degrade an aerospace sensor or cause electrical equipment to malfunction. To guarantee worker safety and project success, all equipment must be made in optimal cleanroom conditions. Aerospace cleanrooms utilize large air showers at the entry and exit to remove particles from people and components, keeping the production area clean and free of contaminants.
    • Pharmaceutical Cleanrooms: Pharmaceutical cleanrooms are essential for developing, testing, and manufacturing life-saving drugs. Contamination in pharmaceutical processes might influence test results or consumer health. Since these cleanrooms must meet stringent cleaning standards, they frequently rely on air showers. The extra degree of security guarantees that individuals passing from outside to inside the compounding room do not bring in potentially harmful contaminants.
    • Medical Research Cleanrooms: Air showers are often found in medical research cleanroom applications involving sensitive equipment. In research studies involving toxic fumes or biohazards like infectious diseases, the inside of the cleanroom may pose more of a threat than the outside. In addition to negative pressurization, air showers are key to removing particles from workers as they exit the cleanroom.
    • Precision Manufacturing Cleanrooms: Although not all production environments have strict particle control specifications, sensitive products like sensors, radar systems, and computer hardware must be produced in a controlled environment. For example, producing defense industry components like weapons, security devices, and other complex equipment requires a highly controlled cleanroom environment.

    Air Showers From Liberty Industries

    Air showers are worth the investment in safeguarding your cleanroom operation. The method is highly effective at addressing the source of the most major potential containment breach—the entrance to the cleanroom. Liberty Industries offers a comprehensive selection of air showers made of different materials and for various cleanroom applications. Our air showers are optimized for low traffic areas, high traffic areas, height restricted areas, and other operational conditions.

    Contact us or request information today to learn more about our high-performance solutions.

    What is an Air Shower?
  2. Product Spotlight Page – Tacky Mats®

    Leave a Comment

    Dirt and other contaminants carried on the bottom of workers’ footwear can build up on floors and eventually transfer onto work surfaces, equipment, and products. Tacky Mats®, also known as cleanroom sticky mats and tack mats, clean shoe soles as people walk overtop them to prevent such particles from entering sterile or cleanroom environments.

    Utilizing Tacky Mats® at the entrance of your facility or cleanroom improves the efficiency of daily operations since employees won’t need to change into disposable shoes or booties before passing into a workroom. Read on to learn about other benefits and applications of these adhesive mats.

    Benefits of Tacky Mats®

    In appearance, Tacky Mats® may be similar to welcome mats you might find outside any typical doorway. You should place your mat in an area with high foot traffic for best results. Tacky Mats® use peelable layers of sticky adhesive that easily remove dirt and other contaminants as they come in contact with footwear to safeguard against polluting a sterile or cleanroom environment.

    By trapping particles in the adhesive as people walk over the mat, the mat’s surface minimizes potential contaminants as part of a two-step process. First, the adhesive holds dirt in place, preventing workers from tracking it into a room or facility. Then, once the sticky mat surface has collected a large amount of dirt and becomes ineffective—typically at around 50 walkthroughs—you can peel away the saturated layer to uncover a fresh one.

    These mats offer economical dirt control and come in varied sizes, making them applicable in different spaces and situations. Typically, the ideal size requires workers to take at least two to three steps across the mat in order to make contact with both shoes and achieve a comprehensive clean. Given their light weight and compact size, these adhesive mats are easy to position and install on tile, vinyl or concrete surfaces.

    Tacky Mats® Applications and Uses

    Tacky Mats® are best suited for areas where cleanliness is important, or for locations containing sensitive materials and equipment. Some common applications include:

    • Cleanrooms and other sterile environments
    • Research laboratories
    • Medical buildings
    • Hospitals & Pharmacies
    • Pharmaceutical applications
    • Foodservice facilities
    • Factories and other industrial or manufacturing facilities for healthcare devices, aerospace components, etc.

    Tacky Mats® From Liberty Industries, USA Made product

    Tacky Mat® is a registered trademark to Liberty Industries Inc. Our company invented the Tacky Mat® and has been manufacturing and distributing high-performance contamination control products since 1953 for cleanrooms and other related applications. We have a wide range of USA made Tacky Mats® for industrial, manufacturing, and commercial environments. Our company designs our Tacky Mats® to ensure that products and processes stay clean and free of contamination. Liberty Industries couples top-quality products with the superior customer service that only an industry leader can provide.

    Browse our catalog of Tacky Mats® to see our available offerings, or contact us today for more information and to request a quote.

  3. The Role of Stainless Steel in Cleanroom Equipment

    Leave a Comment

    Click to ExpandStainless Steel in Cleanroom What to Know

    Since 1953, Liberty Industries has been manufacturing and distributing high-quality cleanroom and contamination control supplies and accessories across the globe. We are your one-stop source for all your cleanroom needs, offering products designed to meet the requirements of various critical environments.

    Stainless steel offers a range of properties that are specifically beneficial to cleanroom environments, making it an ideal material for various equipment. We offer stainless steel air showers, pass thrus, and laminar flow equipment that can be customized to fit your specific cleanroom needs.

    Why Stainless Steel?

    Stainless steel equipment and furniture are mostly preferred for cleanroom environments because they meet stringent hygienic requirements and safety standards. Stainless steel is not only robust and sturdy, but it can also withstand even the most rigorous cleaning processes. Some of the advantages of stainless steel equipment in cleanroom environments include:

    • Versatility. Stainless steel is versatile when it comes to design, allowing stainless steel equipment manufacturers to provide tailor-made solutions complying with various regulatory criteria.
    • Corrosion resistance. High-grade austenitic stainless steel, such as Grade 304, offers unmatched corrosion resistance to various chemicals, acids, and alkali.
    • Easy to clean. Stainless steel is easy to clean and disinfect without the risk of losing its robustness and other properties. Grade 304 steel has no pores or cracks that could house dirt, grime, or bacteria. It cleans easily with soap and water, and it can also withstand more rigorous cleaning processes without corroding.

    Which Stainless Steel Grades Are Used for Cleanrooms?

    Some of the grades of steel often used for cleanroom equipment include:

    Grade 304

    Grade 304 is arguably the most common type of stainless steel used for cleanroom equipment, as it offers a cost-effective option that resists oxidation and corrosion. It contains 18% chromium and 8% nickel but no molybdenum. Cleanroom furniture and equipment made from this material can withstand rigorous cleaning processes without wearing away. Grade 304 stainless steel is known to maintain structural integrity even when exposed to high temperatures of 870° C. It also holds up well when exposed to chloride content up to 200/mg/l.

    Grade 316

    Grade 316 stainless steel is the second most common type of stainless steel in cleanroom equipment. It contains 16% chromium, 10% nickel, and 2% molybdenum. Molybdenum protects against specific forms of corrosion and pitting that result from industrial solvents and cleaners. The big difference between Grade 316 and grade 304 stainless steel is that 316 stainless steel resists chloride corrosion and other harsh chemicals.

    Cleaning Stainless Steel in a Cleanroom

    Some of the tips for cleaning and caring for stainless steel in cleanrooms include:

    • Use warm water and a soft cloth or non-abrasive sponge to clean normal spills and small stains.
    • Where necessary, use a mild soap or detergent to clean stainless steel surfaces.
    • Use recommended solvents such as non-sterile or sterile 70% isopropyl alcohol to clean more stubborn messes such as grease, oil, stains, and fingerprints.
    • Use a clean cloth over all surfaces to prevent water spots.

    Stainless Steel Equipment Available from Liberty Industries

    Liberty Industries provides various stainless steel cleanroom equipment designed to meet your specific needs. These include:

    • Pass Thrus. Our stainless steel pass thrus are constructed of 304-#4 stainless steel. They also feature stainless steel hinges and acrylic doors. Our engineers can tailor-make your product to include custom sizes, an optional interlock system, fire-rated doors, and more.
    • Laminar Flow Equipment. We offer stainless steel peripheral laminar flow cleanroom hoods and table top laminar flow fume hoods to protect against harmful fumes and contamination.
    • Air showers. Our air showers are constructed from 304 #4 – 16 gauge stainless steel and come with heavy-duty anodized aluminum doors featuring 3/16″ safety glass. The doors are equipped with magnetic interlocks, and you can choose either left or right door swings.

    Stainless Steel Cleanroom Equipment from Liberty Industries

    Stainless steel is a very popular material option for various cleanroom equipment due to its many desirable properties and ability to withstand rigorous cleaning processes. At Liberty Industries, we offer durable stainless steel air showers, pass thrus, and laminar flow equipment that can be tailor-made for your specific cleanroom application. To learn more about our stainless steel cleanroom equipment, contact us today. You can also view our full catalog for more information about our other products.

  4. Our Product Spotlight: Shoe Cleaners

    Leave a Comment

    As one of the leading contamination control experts, Liberty Industries has been known for providing high quality cleanroom and contamination control supplies to companies across the globe since 1953. We offer a large selection of products for many industries, including manufacturing facilities, pharmaceutical companies and healthcare companies.

    John J, Nappi, Sr, founder of Liberty Industries, invented the shoe brush cleaner in the late 1960’s. It continues to be one of our most popular products since it can be used outside of cleanrooms as well as industrial applications. We were able to streamline the production process because we only source parts from US manufacturers instead of offshore suppliers. We proudly manufacture the shoe brush cleaner in the United States inside our state-of-the-art Connecticut facility.

    Shoe Brush Cleaners for Your Cleanrooms & Controlled Environments

    Labs, cleanrooms, and similar facilities require a clean environment that is free from contaminants. They are designed to maintain extremely low levels of particulates, including dust and airborne particles. Cleanrooms also usually have a level of cleanliness based on the number of particles per cubic meter at a predetermined molecule measure.

    Facilities must follow certain protocols and buy multiple products to ensure that a specific room is clean enough. A motorized shoe cleaner for cleanrooms is an excellent investment, because it can remove dirt, dust, and other foreign substances from the soles of a worker’s shoes so that potentially dangerous contaminants can’t enter a cleanroom or laboratory environment. The innovative machine can also be placed either inside the gowning room or just outside of the cleanroom entrance. Many companies prefer shoe brush cleaners because they can efficiently clean the bottoms, sides, and tops of a person’s shoes.

    Liberty Industries offers three primary models of shoe brush cleaners:

    1. Shoe Brush 2010SC

      The Shoe Brush 2010SC model, which includes an optional Tacky Mat®, is a fully self-contained system that uses a timing belt between the gear motor and bottom brush assembly. The unit includes a HEPA filter exhaust system that allows it to operate at a 99.99% efficiency rate and is best used prior to entering a cleanroom area. It features an enclosed fan-cooled gear motor and a floating, weight-loaded top brush with a round belt drive and four motor-driven brushes. Workers are notified whenever the HEPA filters are dirty and the easily accessible contamination bag, pull-out dust drawers and filters make them easy to empty or replace.

    2. Shoe Brush 2001 – TB

      The Shoe Brush 2001-TB model has four motor-driven brushes that allow it to clean both the sides, top, and bottom of a worker’s shoes. The 132-pound item, which can be used in a variety of settings both on and off-site, uses a transmission drive and an enclosed, fan-cooled motor.

    3. Shoe Brush 351 Bull Dog

      The Shoe Brush 351 Bull Dog is a heavy duty machine that can quickly and efficiently clean mud, leaves, sand, and other debris that may stick to the bottom of someone’s shoes after they have walked around outside. Visitors and anyone else can use this machine when they come in and before they enter the facility’s office area.

    4. Follow the Proper Maintenance Protocols

      The Cleanroom Classification system is based on the number and size of contaminants within a room or space. The cleanrooms are ranked according to their level of sanitation as determined by the International Standards Organization (ISO), with Class 1 being the most sanitary, to Class 9, which is the least. The ISO standards have strict allowances for particles between 1μm and 5μm. The standards for a cleanroom will vary depending on the industry.

      Facilities can reduce contamination and better maintain a controlled environment by maintaining strict hygiene measures, using protective equipment, using cleanroom supplies and ensuring that workers cautiously enter and exit the area. For this reason, products like a high quality shoe brush machine are important, because they can help reduce the risk of contaminants entering the work area.

      Order High Quality Shoe Brush Machines From Liberty Industries!

      Shoe brush cleaners are a smart investment for facilities in various industries. As one of the largest manufacturers and distributors of top quality cleanroom and contamination control supplies and accessories, Liberty Industries can be your main source for all your cleanroom needs. Feel free to view our product catalog, download our free eBook, and contact us for additional information about our high quality shoe brush machines.

  5. The History & Innovation of the Cleanroom

    Leave a Comment


    Liberty Industries is a leading provider of cleanroom and contamination control supplies for laboratories, healthcare providers, manufacturing facilities, and more. Our innovative solutions are designed to deliver the best results across a wide spectrum of industries and have been a primary contributor to cleanroom history and innovation.

    The legacy of the cleanroom can be initially traced back to French chemist, Louis Pasteur, one of the originators of medical microbiology. His research throughout the mid- to late-1800s revealed the effects of microbes on organic tissue. Through his tireless study, Pasteur discovered that boiling water and air exclusion would prevent meat from decomposing, establishing his namesake process of pasteurization. From this discovery, he also posited that the exclusion of microbes could reduce or prevent the spread of disease, which led to the development of the first cleanrooms.

    Based on Pasteur’s germ theory, British surgeon Joseph Lister first used antiseptics in surgery to create sterile operating rooms. In 1867, he began to use carbolic acid to clean his hands and instruments and found that this significantly reduced bacterial infection in his patients. This successful attempt to control microbial spread in a targeted environment gave rise to the concept of cleanrooms, and in the 1960s the idea truly took root.

    cleanroom diagram

    The Forefather(s) of the Modern Cleanroom

    In the 1960s, scientist Willis Whitfield worked at Sandia National Laboratories, a federally funded scientific research facility in Albuquerque, New Mexico. Whitfield developed the first forced-air filtration system to control the number of airborne particles within an enclosed space. He filed this as the first cleanroom design, called Ultra Clean Room, under U.S. Patent No. 3158457 in 1964, an accomplishment that saw him inducted into the U.S. National Inventors Hall of Fame.

    Whitfield used gravity and forced air circulation to create a controlled space with extremely low levels of particulate matter. The circulation initiated at the top of the room, where incoming air was forced into the enclosure through HEPA filters in the ceiling. Particulate matter was forced to the ground and drawn out at the bottom of the room. Though the first cleanroom was only able to hold a single adult male, cleanroom technology has since evolved rapidly and now sees broad usage across a variety of large-scale operations, from medical research facilities to electronics manufacturing.

    liberty industries facility 1960s

    John Nappi, Sr. & the Evolution of Liberty Industries

    In 1953, Liberty was founded by John Nappi, Sr. under the name Liberty Machine Company. A visionary entrepreneur and inventor, John Nappi designed and manufactured tooling and machinery for companies throughout Connecticut. With the advent of cleanrooms in the 1960s, the company was uniquely suited to provide innovative contamination control solutions for a wide range of cleanroom applications.

    As cleanroom technology advanced, John Nappi continued to develop useful and practical products, including Tacky Mats®, Shoe Brush Cleaners, air showers, and laminar flow devices. In the 1960s, he updated the company’s name to Liberty Industries, Inc. to reflect its new mission and diversified specialization.

    John Nappi’s son, John J. Nappi, Jr., followed in his father’s footsteps by acquiring the business in 1973.  The company has continued to develop advanced cleanroom and contamination control technology for a wide range of industries, including pharmaceutical, medical, nuclear power, electronics manufacturing, aerospace, and precision manufacturing.

    Over the course of many decades, Liberty has evolved from a small machine shop manned by an intrepid entrepreneur to a world-class manufacturer of state-of-the-art cleanroom technology. Our company continues to push the boundaries of the industry, acquiring the latest manufacturing technology and continuously developing new products and processes. No matter how advanced our technology has become, we hold to the values our company was founded under in 1953: honesty, integrity, commitment, and reliability.

    As Liberty Industries has grown, so has the Nappi family. As a family-owned and operated company, Liberty has seen the introduction of a third generation in John J. Nappi, Jr.’s son, Giovanni J. Nappi III. Giovanni has been around the business his entire life and understands every aspect from the ground up. He initially founded Liberty Coatings in 2006, a subsidiary of Liberty Industries Inc. which provides Cerakote® finishes to industry-leading manufacturers in the sectors of firearms, automotive, and industrial coatings.  Liberty Coatings operates with the philosophy that when high-quality services are offered, delivered on time, and at a competitive price, the company will exceed clients’ expectations.  The coatings division has contributed to the range of diversity in the Liberty Industries customer base. Due to John J. Nappi Jr. and his son Giovanni’s direction, the company continues to grow and prosper through quality product manufacturing and innovation.Nappi family Liberty Industries

    Liberty Industries for All Your Cleanroom Needs

    With a firm foundation in the fundamental science of cleanroom technology, Liberty Industries has scaled the heights of cleanroom and contamination control technology. As a world-class leader in the development and manufacture of cleanroom products, we employ some of the finest minds in the industry to help our customers find the ideal cleanroom setup and supplies for any project. Contact our experts today to learn more about our cleanroom and contamination control products and services.


  6. The Importance of Differential Pressure in Cleanrooms

    Leave a Comment


    At Liberty Industries, we serve as a one-stop source for all cleanroom needs. For over six decades, we have supplied superior cleanroom and contamination control supplies to customers across the globe. Equipped with extensive industry experience, our team has the knowledge and skills to design and develop a standard or custom cleanroom solution suitable for any critical environment.

    In the following article, we provide an overview of one of the key operating principles of cleanrooms—differential pressure. We outline what it is, how we measure it, and how it affects other conditions in a cleanroom.

    Differential Pressure in Cleanrooms

    Differential pressure refers to the difference in air pressure from one location to another within a system. In cleanrooms, maintaining the right amount of differential pressure—either positive or negative—is essential to preventing contamination.

    • In positive differential pressure cleanrooms, the internal pressure is greater than the external pressure to prevent the ingress of any contaminants through any opening—whether intended or accidental—in the cleanroom.
    • In negative differential pressure cleanrooms, the external pressure is greater than the internal pressure to prevent the egress of any potentially harmful compounds contained within the cleanroom.

    Combined with appropriate temperature, humidity, and airflow level, proper differential pressure levels ensure both cleanroom designs work as intended. As such, it is essential to carefully measure and monitor pressure inside and outside of the cleanroom to confirm the differential remains within the acceptable range.

    Industry professionals often employ visual gauges or meters to facilitate the identification of current pressure levels inside and outside of cleanrooms. The devices are designed to automatically calculate and output the difference between two pressure points in the cleanroom (typically two inlet points), eliminating the need for operators to manually monitor separate gauges and calculate the difference between the results. More advanced measuring instruments may offer additional capabilities for monitoring temperature, humidity, and other cleanroom parameters.

    At Liberty Industries, we offer Magnehelic gauges for these applications. They provide accurate measurement of pressure, pressure differential, and vacuum to 2% of full scale. In addition to cleanrooms, typical use cases include automatic valves, control equipment, and gas-air ratio controls.

    Cleanroom Standards

    The level of cleanliness required from a cleanroom depends on the industry and industrial application. For this reason, cleanrooms are available in numerous classifications, each of which denotes a specific level attainable based on the number and size of contaminants with the given space.

    The International Organization for Standardization (ISO) categorizes cleanrooms from ISO 1 to ISO 9, with ISO 1 having the fewest contaminants per square meter. In addition to the number of particulates, the size of particulates also plays a crucial role in ISO classification. Contaminants are measured in microns, from 1μm to 5μm, with different cleanrooms offering different filtration capacities for each size. For example, cleanrooms with HEPA filters remove particulates as small as 0.3μm with 99.99% efficiency rates, while cleanrooms with ultra-low particulate filters remove particulates as small as 0.12μm with an efficiency rate of 99.999%.

    The effectiveness of the mechanisms that facilitate cleanroom operations—including the filters—depend on many factors remaining within tolerable levels. These factors include pressure, temperature, humidity, and airflow, all of which can help or hinder the attainment and maintenance of proper cleanliness levels.

    Quality Cleanroom Solutions From Liberty Industries

    Cleanrooms play a critical role in many sensitive industries and industrial applications. For these instruments to work correctly, maintaining proper differential pressures (among other factors) is essential. To learn more about cleanrooms and the role differential pressure plays in their operation, contact us today. For assistance selecting and sourcing a cleanroom solution for your facility, request a quote.

  7. Cleanroom HVAC Systems 101

    Leave a Comment


    Founded in 1953, Liberty Industries has since established itself as a premier manufacturer and distributor of cleanroom and contamination control supplies and accessories. Equipped with almost seven decades of industry experience, we can design, build, and install some of the highest quality cleanrooms with top-of-the-line components, including cleanroom HVAC systems.

    The following blog post provides an overview of HVAC systems for cleanrooms, outlining design basics and key design considerations.

    HVAC systems for cleanrooms

    The Basics of HVAC Design

    Heating, ventilation, and air conditioning (HVAC) is an umbrella term for the systems used to maintain conditions—e.g., temperature, airflow, and humidity—within indoor areas. They are used in industrial, commercial, and residential facilities to ensure environmental conditions are comfortable and optimal for the necessary operations. When integrated into cleanrooms, they are critical to the maintenance of air quality levels for applications involving sensitive materials or requiring the containment of potentially hazardous materials.

    Conventional and cleanroom HVAC systems have some overlapping functions—i.e., enabling industry professionals to control temperature, humidity, and airflow to achieve comfortable living and working conditions. However, the HVAC systems for cleanrooms also perform more advanced functions—such as monitoring and maintaining air supply and flow patterns, filtering out contaminations, and preserving pressure differentials—to ensure the enclosed area is suitable for sensitive and/or dangerous material operations.

    The design of a cleanroom HVAC system changes depending on the requirements and restriction of the application, including  ISO classification , temperature, humidity, and pressure specifications.  Some of the key components include:

    • Air handling units (AHUs)
    • Air ducts
    • High-efficiency particulate air (HEPA) filters
    • Air diffusers
    • Air return pathways and equipment
    • Air quality monitoring and control systems

    Considerations During the Design Phase

    When designing and planning a cleanroom, there are several factors to keep in mind to ensure the finished structure meets the needs of the application. While designs may vary depending on the operations performed within the cleanroom some of the key considerations include:

    Airflow Capacity

    The airflow capacity of a cleanroom (indicated in cubic feet per minute) affects how many air changes are performed per hour. This characteristic, in turn, depends on several factors, such as the cleanliness level required, the number of personnel and equipment/supplies, the size and number of rooms, and the movement of the people and materials into and out of the cleanroom. While commercial HVAC systems perform less than two air changes per hour, cleanroom HVAC systems generally do 10 to 600 air changes per hour. The higher air change frequency is necessary to prevent particles from settling in the cleanroom.

    Airflow Pattern

    Airflow patterns within cleanrooms generally take one of three forms: laminar (unidirectional), turbulent (non-directional), or mixed-flow. The pattern appropriate for a cleanroom depends on the design and application.

    Pressure Differential

    Cleanrooms are available in positive pressure or negative pressure variations. Positive pressure cleanrooms are used to keep contaminants out, while negative pressure cleanrooms are designed to keep potentially hazardous materials in.

    Employees and Equipment

    Both employees and equipment are sources of contamination for cleanrooms. When brought in or out, they may allow particulates and pollutants to come into the controlled environment or hazardous materials to escape into the outside environment. With this in mind, cleanroom personnel must commit to rigorous health and safety protocols such as wearing the correct personal protective equipment (PPE), going through decontamination areas and bringing in or out only cleared supplies and materials.

    Other factors that employees influence include the number of air changes required per hour (more employees mean more air changes) and the temperature levels (cleanroom temperature must be within comfortable levels for human operators).

    Cleanroom Layout

    The layout of a cleanroom affects the efficiency and effectiveness of the HVAC system. For example, the positioning of equipment and air input/output points can help or hinder the filtration of particulates.

    Design Considerations for Cleanrooms

    Design and Construct Your Cleanroom With Liberty Industries

    For all your cleanroom needs, turn to the experts at Liberty Industries. We provide cleanroom design, construction, and installation services as well as all related supplies and accessories to deliver a complete solution.

    For additional information about our cleanroom capabilities, download our eBook or contact us today. To receive pricing details, request a quote with your cleanroom requirements.


  8. The Design & Classifcations for Pharmaceutical Cleanrooms

    Leave a Comment


    Cleanrooms are used in a broad range of industries to facilitate careful control of environmental factors such as air quality, pressure, temperature, and more. Liberty Industries is an industry leading pharmaceutical cleanroom manufacturer and a global distributor of accessories and supplies. We act as a single source supplier for any cleanroom needs. The quality of our products is matched only by our commitment to customer service.

    At Liberty Industries, we’ve provided cleanrooms for customers in an expansive range of industries, including the pharmaceutical sector. Our experienced engineers will gladly customize any of our products to fit the unique needs for any application. With a great deal of experience designing and constructing pharmaceutical cleanrooms, you can be sure that our skilled team will provide a solution.

    Designing a Pharmaceutical Cleanroom

    A variety of products cannot be manufactured safely outside of a cleanroom. This is especially true for pharmaceutical products, which must maintain strict purity levels. Cleanrooms are designed to carefully control important environmental factors to mitigate the risk of product or sample contamination.

    What Kind of Cleanroom Do I Need?

    The level of cleanroom cleanliness required for a pharmaceutical cleanroom can vary depending on the product. Some pharmaceuticals are considered to be non-sterile medical products. This means that the cleanrooms used in their production typically only require filtered air and effective ventilation. Conversely, sterile medical products require much stricter environmental controls for their cleanrooms.

    corridors for pharmaceutical cleanrooms

    Clean and Dirty Corridors

    Different product types face separate risks that can be addressed by applying positive and negative pressure to the cleanroom as required;

    • Clean corridors. Pills and tablets made from powders aren’t friendly to microorganisms, but they do pose a risk of cross-contamination between products. As such, most cleanrooms for these products are negatively pressurized to keep powders from drifting out of the room and into other parts of the manufacturing facility. This is known as a “clean corridor” system.
    • Dirty corridors. Cleanrooms for biopharmaceuticals, liquids, or aseptic will be positively pressurized to keep microorganisms from entering the space. This is known as a “dirty corridor” set up.

    Of note, doors should always open into the area with the higher pressure to avoid contamination.

    Keeping a Cleanroom Clean

    There are many processes working in conjunction to maintain the desired environment and cleanliness in pharmaceutical cleanrooms. Some of these include:

    • Air filtration. Air handling systems are designed to maintain enough airflow within the space to keep particulates from settling on surfaces. The higher the cleanliness standards of the cleanroom, the more air must be used for this purpose. HEPA filters and ULPA filters are used to catch these particulates and filter them out of the airflow.
    • Air circulation. Excess moisture in the air of the cleanroom can be detrimental to the viability of many different types of pharmaceutical products. In instances where humidity must be controlled, air handling systems will be designed to recirculate less air. Instead, they supply fresh air into the room to push the moisture safely outside. The same process for removing humidity can also remove toxic elements created from production processes or raw materials.
    • Surfaces. It’s critical that all surfaces in a cleanroom are completely smooth. Microorganisms and other contaminants can build up in cracks and grooves, ultimately impacting the cleanliness of the cleanroom. Surfaces should be easy to wipe down, shouldn’t contain coatings that could peel or crack, and should be resistant to cracking or denting from impacts.

    Pharmaceutical Cleanroom Classifications

    No cleanroom is 100% free from contaminants. However, cleanrooms are defined by the concentration of particles per cubic meter within the cleanroom environment. ISO 14644-1 is the most widely followed classification system for pharmaceutical cleanrooms, with ISO 1 as the highest level of cleanliness and ISO 9 as the lowest.


    The U.S. Food and Drug Administration (FDA) strictly regulates cleanroom use within the United States. FDA rules for cleanrooms are adapted from Current Good Manufacturing Practices (CGMP) regulations. Pharmaceutical manufacturers are also subject to CFR 210 and 211 from the Current Good Manufacturing Practices for Finished Pharmaceuticals. When a rule exists that targets a specific drug product, that rule always supersedes CFR 210 and 211.

    • Design and construction. Regulatory enforcement begins with the design phase of the cleanroom to ensure that the finished product achieves appropriate clean air standards.
    • Monitoring. Beyond the cleanroom itself, the FDA also requires a separate room with monitoring and control equipment for air pressure, dust, humidity, microorganisms, and temperature.
    • Cleanliness levels. The FDA also requires the installation of a compliant air filtration system and written standard operating procedures for cleaning, sanitization, and contamination prevention within the cleanroom.

    Ask the Cleanroom Experts

    The regulations surrounding the design, construction, and operation of cleanrooms are highly complex. At Liberty Industries, we’ve been in the cleanroom business since our inception in 1953 and we understand all of the rules and challenges involved with installing a new cleanroom.

    For more information about our cleanroom solutions or capabilities, please don’t hesitate to contact us or submit a request for information. To learn more about the design and construction of cleanrooms, please download our eBook.


  9. A Guide to Cleanroom Cleaning & Maintenance

    Leave a Comment


    At Liberty Industries, we build high-quality cleanrooms with customizable designs. We offer myriad products to create specialized environments and offer complete installation services. Since 1953, we have been providing industrial companies comprehensive solutions and contamination control supplies, including those pertaining to cleanroom cleaning. 

    Cleanrooms use a variety of mechanisms to reduce the risk of contamination, such as vertical flow component systems for airflow and Tacky Mats® that capture dirt and dust. Regular cleaning and maintenance of cleanrooms ensures optimal operation so products don’t fail inspection and research results don’t become contaminated.

    How to Clean a Cleanroom

    Dirt, dust, and contaminants may enter even the most carefully controlled cleanroom as people enter and exit, with material shipments, and more. There are two main categories of contaminants: physical contaminants generated by the cleanroom itself, and process or human action contaminants from cleaning, the movement of goods, and particulates from skin and hair. Floors, work areas, walls, ceilings, and vents must be wiped down during and after each session to keep the environment sterile and secure.

    Cleanroom floors can easily become contaminated over time as dust and other particulates settle. At Liberty Industries, we recommend that facilities regularly follow a comprehensive process to clean floors. This process should include the following:

    • Vacuuming the surface to remove any loose dirt and debris.
    • Next, rinse the floor with deionized water and a certified cleansing solution to break up films or dried contaminants. 
    • Once the floor is dry, vacuum it again to remove every trace of debris disturbed during the mopping process. 
    • For larger cleanrooms, it’s important to change the water between rooms or every 15 square feet to reduce the risk of cross-contaminating separate spaces.

    Companies should also implement preventative measures to reduce contamination in the first place. These steps include Tacky Mats®, air showers, and shoe covers that keep debris from reaching the cleanroom environment in the first place.

    The floor isn’t the only surface that suffers from contamination. It’s just as important to wipe down work surfaces, gowning areas and benches, pass-thrus, walls, and windows. Vertical surfaces can capture contaminants circulated through the air and may also become contaminated at high touch points. 

    We recommend using wipes and sponges that are specifically designed for cleanroom applications. These cleaning tools have less breakable fibers and are much less likely to create debris. Lint-free 70% IPA wipes, in particular, present minimal risk of debris. HEPA filter hand dryers are also available.

    Liberty Industries distributes cleaning materials for a variety of different cleanroom environments. We carefully source and recommend products that help our customers maintain their cleanroom’s rating. Some of the products we provide include:

    • LIB8312 Sterile IPA  30/70, 12 oz, 16/cs
    • CRF440 Cleaning agent, 20 oz 
    • 8025 Econowipe, 9 x 9 wipes, 6 tubs/cs, 300 per tub 
    • LN-10 Urethane sponges
    • HEPA filter vacuums such as our CRV 7347 model

    Additional Cleanroom Maintenance

    Keeping your cleanroom in spec should be one of your facility’s top priorities. Additional steps your team can take to ensure high-quality production and testing conditions include:

    • Instituting a regular schedule of daily, weekly, and monthly cleaning tasks.
    • Using polycarbonate shields when lubricating equipment that prevent the lubricant from contaminating the space.
    • Maintaining positive-pressure airflow before, during, and after cleaning procedures.
    • Keeping detailed records about acceptable margins of contamination and the cleanroom’s adherence to standards of cleanliness.
    • Ensuring workers having the necessary gowns, gloves, shoe covers, and other shielding materials to reduce contamination during cleaning procedures.
    • Create detailed plans and assign responsibility for each cleaning task so your cleanroom is never in violation of cleanliness standards.

    Cleanroom Construction, Maintenance, and Support From Liberty

    Cleanrooms require a lot of care and maintenance to keep them operating in accordance with regulations and industry standards. At Liberty Industries, we don’t just create and install cleanrooms. We can provide our customers with the tools and cleaning supplies to assist them in maintaining their required cleanroom needs. 

    Contact our team or request a quote for more information about best practices and leading products for cleanroom maintenance and cleaning.


    cleanroom maintenance checklist


  10. Is a Controlled Environment the Same as a Cleanroom?

    Leave a Comment


    Liberty Industries has prominently put itself forward as a manufacturer and supplier of high-quality cleanroom and contamination control products for customers around the world since 1953. We are pleased to offer a broad range of customizable products for controlled environments and cleanrooms, so our customers are sure to find everything they need in one place. Our wide range of critical environmental products include cleanrooms, air showers, fan filter units, pass-thrus, laminar flow benches, shoe brushes, Tacky Mats®, and a variety of accessories such as vacuums and cleanroom clothing. 

    In order to ensure that you choose the best facility and equipment for your critical environment needs, it is important to have a clear understanding of the difference between a controlled environment and a cleanroom. Although both environments have similar traits, a cleanroom must follow more rigorous regulations and standards.

    Is There a Difference Between a Controlled Environment and a Cleanroom?

    Cleanrooms and controlled environments are very much alike, but the specifications for each differ in severity. While controlled environments largely entail the control of factors such as air pressure and temperature, cleanrooms require these environmental controls plus decontamination and filtration. For this reason, cleanrooms require a great deal of specialized design and equipment that is not necessary in a controlled environment.  

    Controlled Environment

    A controlled environment, also known as a critical environment, is a space with precisely regulated environmental factors. Air temperature, temperature, and humidity are regulated to meet operational needs, and the critical area is isolated from other operations within the facility. The level of particle contamination is not measured and controlled environments are not required to meet the same high decontamination standards as cleanrooms. 


    Cleanrooms are used to create a particulate free environment free of contaminants such as dust, mold, and microorganisms. They are actually a type of controlled environment and must still maintain rigorous environmental control and segregation from external environments. 

    However, the environmental conditions within the cleanroom must adhere to much more stringent regulations. For example, cleanrooms are required to meet certain standards for the acceptable volume of particle contaminants in the air. This means that specialized filtration and cleaning technology must be employed to different degrees, depending on the application and industry for which the cleanroom operates.

    The level of decontamination is determined based on the classification required for the industry and application. Cleanroom standards come from a variety of sources, including;

    • Good Manufacturing Practices (GMP)
    • Food and Drug Administration (FDA)
    • Deutsches Institut für Normung (DIN)
    • European standards (EN)
    • International Organization for Standardization (ISO) 14644-1 

    ISO 14644-1 establishes 9 classifications for particle contamination, wherein Class 1 is the most stringent and Class 9 the least. Depending on the application and industry, standards and regulations will establish the level of acceptable particles per cubic meter, and the acceptable size of those particles, measured in micrometers (μm). 

    Choosing the Proper Cleanroom

    Cleanrooms for controlled environments are tailored to meet the specific needs of the industry and application they serve. Cleanroom contractors will consider a wide range of factors when determining the construction materials and environmental regulating equipment. In order to ensure that the facility is accurately and thoroughly equipped, the contractor will consider the following:

    • Level of required cleanliness (i.e. ISO class, FDA regulations)
    • Types and placement of filters (HEPA or ULPA)
    • Environmental conditions 
    • HVAC requirements
    • Spatial specifications
    • Construction materials
    • Air showers and/or pass-thru units
    • Fire protection
    • Light and air supply and filtration
    • Electrical and plumbing requirements
    • Equipment hookups and special equipment

    Choosing the best cleanroom for your needs means understanding the specific requirements for your industry. Cleanrooms are used in a wide variety of industries and applications, including:

    • Pharmaceutical
    • Aerospace
    • Medical
    • Biotechnology
    • Food & beverage

    Each industry must adhere to the requirements of its own regulatory bodies, broader industry standards for cleanrooms, and accepted best practices.

    Controlled Environment and Cleanroom Equipment and Supplies 

    With over 60 years of experience, Liberty Industries understands that each critical environment has very specific needs. Our highly knowledgeable and experienced team of engineers will help you design and tailor your controlled environment equipment and accessories to meet your company needs and the most stringent industry standards. For more information on our critical environment products, contact us today or request a quote



Have Any Questions?

Click Here!