3 Medical Industries that Use Negative Air Pressure Cleanrooms

3 Medical Industries that Use Negative Air Pressure Cleanrooms

It’s a well-known natural process for air to flow from high to low pressure. Examples of this are found around us every day. Wind and weather are formed from the uneven heating of the earth’s surface which generates pockets of high and low pressure air. If you’ve ever witnessed the sudden closing of a door as air is sucked out of a room where no breeze was felt, what you experienced was the high pressure air moving to a low pressure area to achieve stasis. 

High and low pressure, or positive and negative pressure, can be used as a tool in cleanroom environments to protect against entering contaminants (in positive pressure cleanrooms) or contaminant leakage (in negative pressure cleanrooms). We’re going to focus on negative pressure cleanrooms, how they work, and how they are especially important in some medical cleanroom applications. 

 

What are Negative Air Pressure Cleanrooms?

 

In a cleanroom, pressurization can be achieved using airflow and air direction. Negative pressure cleanrooms exhaust more air than they supply to create a lower pressure than is found in the surrounding rooms. Negative pressure in cleanrooms is useful because it prevents any contaminants or hazardous substances inside the cleanroom from leaking out where they could contaminate adjacent rooms or endanger employees.

Negative pressure is used in sensitive applications where processes or substances within the cleanroom could be hazardous to work or health outside. Negative pressure is a simple way to further limit the possible escape of harmful particles, fumes, or substances, when used effectively with proper filtration and adequate ventilation.

How Negative Pressure Cleanrooms Work

 

To achieve negative air pressure, external exhausts pull air from the cleanroom at a faster rate than air is introduced over a span of time. The resulting negative pressure means air will want to flow into the cleanroom to fill the low pressure area, effectively stopping contaminants from going against that natural movement in order to escape the cleanroom.

In order for the negative pressure cleanroom to work, adjacent spaces must be maintained at a higher pressure than that of the cleanroom. A slight difference in pressure will prove effective at limiting contaminants, but the greater the pressure differential, the stronger the force of air that wants to move to achieve equilibrium, and thus the greater the resistance for contaminants to move the opposite direction. However, it is possible to have pressure that is too negative, as this could force contaminants into the cleanroom, where they could be detrimental in some applications.

Some cleanrooms only require a slightly negative pressure in order to contain aerosols, while others require a higher pressure difference to aid in containing hazardous liquids or gases from transferring in pass-throughs or other access points. Depending on your application, you may choose a higher pressure differential in order to limit the possible escape of hazardous liquids or toxic fumes. In any case, having a pressure monitoring system is important to ensuring balance and consistency within your cleanroom. If you’re exploring negative pressure cleanroom design, it’s a good idea to build in a monitoring system so you can always check and alter pressure as needed.

Determining Where to Use Negative Pressure in Cleanrooms

 

Negative pressure can be used in a small area, as the total cleanroom pressure, or in part of the cleanroom design such as in a passthrough, workstation, or storage cabinet. An external exhaust removes air and airborne contaminants, odors, or fumes, and prevents hazardous, toxic substances from escaping the negatively pressurized space. 

Some cleanrooms require an enclosed space within the cleanroom to be at a different pressure than surrounding spaces. These are known as negative pressure rooms and are commonly found in pharmaceutical or medical research cleanrooms working with hazardous compounds or infectious particles. Negative pressure rooms are an example of a segmented cleanroom, where other segments may meet different classification requirements or have different needs for pressure, cleanliness, or operating procedures.

Medical Industries and Negative Air Pressure Cleanrooms

 

Negative pressure cleanrooms are particularly useful in medical applications where the work involves hazardous compounds, toxic fumes, or infectious substances. A few examples of medical industries that use negative pressure cleanrooms are hospitals, medical research laboratories, and the pharmaceutical industry.

Hospital Cleanrooms

 

Hospitals use negative pressure cleanrooms to contain airborne contagions, pathogens, and viruses.

Whether for research, treatment, preventative isolation or quarantine, negative pressure helps seal in dangerous contaminants to keep hospital staff and patients safe. Hospital cleanroom applications that work with hazardous drugs or infectious diseases are often required to use negative pressure when handling products and treating patients. 

Medical Research Cleanroom

 

Medical research, especially that which involves hazardous substances, aerosol contaminants, or toxic waste, is generally done within the confines and protection of a biosafe cleanroom. Negative pressure is used to prevent any harmful particles from escaping the cleanroom where they could contaminate other spaces or endanger human or animal lives. Negative pressure cleanrooms protect researchers by containing hazardous materials or substances within the cleanroom, where staff is prepared with proper gowning and protective equipment. 

Pharmaceutical Cleanrooms

 

Pharmaceutical cleanrooms, particularly those that must comply with USP 800 standards for sterile and non sterile compounding of hazardous materials often require negative pressure to operate safely. Negative pressure cleanrooms allow for safer handling of hazardous drugs, presenting fewer risks to employees and consumers. USP 800 pharmaceutical cleanrooms require a dedicated water channel gauge to monitor pressurization, ensuring that the differential is high enough to be effective, but not too high where it could reduce efficiency and potentially bring contamination into critical parts of the cleanroom. 

Negative pressure cleanrooms are helpful in cleanrooms where the emphasis is on containing the work, product, or processes within the cleanroom. Although they are particularly useful in many medical cleanroom applications, some negative pressure cleanrooms can be found in other industries where hazardous materials need to be controlled. 

Need a negative pressure cleanroom for your sensitive application? At Angstrom Technology, we have the tools and expertise to design the cleanroom that best fits your application and your budget. For a free quote, reach out to our team.

Static Control for Medical Device Cleanrooms: Everything You Need to Know

Static Control for Medical Device Cleanrooms: Everything You Need to Know

Even with a powerful HVAC system, a multi-stage HEPA filtration process, and thorough cleaning procedures, contaminants can still threaten a controlled cleanroom environment. Static electricity is common everywhere we live, but in a cleanroom it can be unpleasant, detrimental, and even dangerous. How can the dangers of static affect your application? How can these problems be avoided? Let’s explore static electricity in medical device cleanrooms, and how to build static control into your cleanroom design from the ground up.

 

Why Does Static Matter?

Static electricity is caused by an imbalance of positive and negative charges on a surface or object. These charges accumulate until they’re neutralized or discharged. It’s a common phenomenon in all parts of the world and is usually harmless. In a cleanroom, however, the buildup of static electricity can be dangerous to products and employees. 

Static electricity in cleanrooms can present dangers to any industry, but in medical device manufacturing, assembly, and packaging it could have disastrous, life-altering consequences. Three ways static can influence with medical device cleanroom safety and efficiency are by:

 

Attracting Contaminants

Static causes contaminants to adhere to charged surfaces through electrostatic attraction (ESA). ESA can occur in many stages of product development and assembly but is perhaps most dangerous in packaging. Particularly if products are packaged using plastic, they can carry charges that are not neutralized during shipping. Once opened, contaminants are attracted to the device, causing it to fail or be rejected. 

 

Inhibiting Equipment

Static that accumulates during product development can interrupt important processes. If parts of the device are repelled or attracted to machinery or equipment it can contaminate them or cause a slowdown in operations, reducing your cleanroom’s efficiency and increasing operational costs.

 

Generating Charges

Static charges that accumulate on surfaces, equipment, personnel, and products that are not properly discharged or neutralized can interfere with electronics or hardware you use to create devices or the devices themselves, causing them to malfunction or fail. Static charges can also create electric shocks, which, while not likely to cause extreme bodily harm, could cause involuntary movement which could lead to accidents or damage to the employee, delicate equipment, or devices. 

Managing static effectively is crucial. Even when the effects of static electricity in medical device cleanrooms are not threatening to the devices you develop, assemble, or package, they may interfere with efficiency and affect operational costs of your facility.  How do you control static in your cleanroom? Many potential problems can be addressed in your cleanroom design and then managed with specific static control cleanroom supplies.

 

Static Control Methods in Cleanroom Design

Cleanroom design can incorporate methods to conduct, dissipate, or neutralize static electricity.

 

Conduction

In conduction, materials or surfaces that present little resistance to the flow of electrons are used to guide charges to the ground safely. Conductive materials direct charges away from where they can damage products or attract contaminants. 

 

Dissipation

Dissipation, similar to conduction, is the flow of charges to the ground, but occurs more slowly and in a more controlled manner. Materials that allow electrostatic discharge through dissipation can be used in flooring, wall materials, and furniture. ESD products discourage the buildup of static electricity to protect products, employees, and cleanroom operations. 

 

Neutralization

To neutralize static, the imbalance of charges must be corrected through adding electrons to positive charges or removing electrons from negative charges. Air ionization is one method more medical cleanrooms are adopting to neutralize air and surface charges. 

An air ionization system adds positive and negative ions to the atmosphere of your cleanroom, directing them with a focused nozzle or blower. The ions are attracted to charged surfaces of the opposite polarity, balancing and effectively neutralizing the surface. Air ionization systems can be incorporated in key areas of production of medical devices, as well as at entry points of the cleanroom to limit the introduction of charges into the cleanroom by employees.

 

Static Control Equipment Cleanroom Supplies

To control static electricity and prevent harmful effects including damage to your equipment, employees, and products, anti-static cleanroom supplies are used to manage static or avoid the generation of excess charges. These could include:

  • Air showers
  • Ionizing blowers
  • Sticky mats to collect contaminants
  • ESD safe furniture such as chairs and workstations
  • ESD garments, gloves, and footwear 
  • ESD monitoring equipment

Static control is also important for cleanrooms using fine electronics and sensitive or flammable substances. In the medical industry the production of medical devices might be the application most threatened by static electricity. With intentional cleanroom design and static control cleanroom supplies, you can protect your products and people, encourage efficient operation, and avoid the potential problems of escalated costs or failed products. 

Think you need static control in your medical cleanroom, but not sure where to start? Angstrom Technology can design and build cleanrooms to your specifications using conductive flooring, ESD materials, static control equipment, and more. We have solutions to avoid static buildup and protect your work and employees. Get in touch with our team to learn more.

Medical Cleanroom Design Tips: Choosing Cabinetry

Medical Cleanroom Design Tips: Choosing Cabinetry

Choosing cleanroom cabinets requires some thought, as there aren’t clear guidelines for which are best for every cleanroom application. No official certification system exists for cabinetry the way other cleanroom materials are declared safe for use in cleanrooms. It’s important to carefully consider a few factors when making your choice, such as your medical cleanroom classification, what materials are compatible for use within your facility, and how your cleanroom cabinets will be used.

Medical cleanroom cabinets are used for safely storing products and substances to keep them out of the way in a cool, dry environment. You can use cleanroom cabinets for storing various items including:

  • Tools and equipment
  • Biological samples
  • Hazardous substances
  • Cleaning supplies
  • Gowns and booties
  • Industry-specific products

 

Types of Cleanroom Cabinets

Not every cabinet will be compatible with your cleanroom. The ideal cabinet for your application will be functional and space-efficient, and not introduce contaminants into the cleanroom nor allow them to collect on the material. Here are a few common medical cleanroom cabinet materials.

 

Stainless Steel Cleanroom Cabinets

Stainless steel cleanroom cabinets are the most popular style because they function well in many different types of cleanrooms. Great for diverse applications, stainless steel can handle wet or dry conditions and a wide range of temperatures. Stainless steel also has the advantage of being easy to maintain and sanitize. 

These cleanroom cabinets can build up static electricity, so they should be used in a cleanroom where static isn’t a threat, or adapted with a grounding or dissipation system built into the cabinet design. (Tip: For superior corrosion resistance, consider electropolished stainless steel.)

 

Open Wire Shelving

If your cleanroom uses a vertical airflow pattern, you may instead choose wire shelving over cabinets, in order to let the air move freely and limit the collection of contaminants. Either chrome-plated wire or polymer shelving are both great options that are about a third the cost of stainless steel. Open wire shelving is best for cleanrooms that don’t use corrosive agents in operation or for cleaning.

 

Laminate Cleanroom Storage Cabinets

Laminate cleanroom cabinets are an affordable choice for storage in cleanrooms with less stringent requirements. These cabinets are available in a variety of configurations with adjustable shelves. They can be either wall mounted, freestanding, or on casters.

 

Epoxy Cleanroom Cabinets

An epoxy coating can be applied to cleanroom cabinets and surfaces to increase stain resistance. Epoxy cleanroom cabinets work well for wet and dry applications.

 

Polyurethane Cleanroom Cabinets

Polyurethane is another coating similar to epoxy, but with greater chemical resistance. Polyurethane cleanroom cabinets have a smooth surface that is easy to clean and difficult to scratch or chip.

 

Acrylic Cleanroom Cabinets

Clear acrylic cleanroom storage cabinets are great for protecting products, parts, and substances. Using transparent cabinets can limit unnecessary movement in the cleanroom, reducing the risk of contamination.

 

Choosing Cleanroom Cabinets

As an important part of cleanroom design, all storage solutions like cleanroom cabinets and shelves used in a controlled environment must be compatible with cleanroom use and limit contaminant collection. Consider your cleanroom’s airflow pattern when choosing cabinets or shelves and avoid obstructing your HVAC and filtering system. Your cleanroom cabinets should also be able to withstand the materials you use for cleaning without corroding or shedding particles. Finally, if your cleanroom operations or staff are endangered by static electricity, avoid conductive materials unless you have a method to ground charges.

If you’re still not sure which cleanroom cabinets are best for your cleanroom, let Angstrom Technology help. As cleanroom design experts, we can help you choose the option that’s best for your application, and that meets your cleanroom classification. For more help choosing cleanroom cabinets and other furnishings, give us a call or reach out online

New Trends in Cleanroom Design

New Trends in Cleanroom Design

Now that the holidays are over and the new year has begun, you might finally be getting around to implementing a new cleanroom in your facility. If you’re designing a new cleanroom or updating your current one, here are the latest trends in cleanroom design that you should consider as you design your cleanroom space.

 

Sustainability

Sustainability is an important consideration for all of us, including corporations. Because cleanrooms use so much energy to maintain the desired environmental conditions, engaging in sustainable practices when possible is crucial. Not only do these sustainability efforts support the natural environment, they are also energy efficient, which can help you save on energy costs. Using energy efficient equipment and energy efficient LED lighting can aid in sustainability efforts, as can a modular cleanroom. Modular cleanrooms can be altered and right-sized as the needs of your company change, while reusing the modular components, and require less material than traditional construction. Additionally, modular cleanrooms can make use of the currently existing HVAC and ventilation systems in your space, rather than requiring separate systems.

 

Transparency

Now, more than ever, we’re aware of the value of transparency from leaders and companies. When it comes to your cleanroom, the primary concern will always be the integrity of the controlled environment within, and it may also be important to maintain privacy for the safety of intellectual property, but cleanrooms can benefit from some openness and visibility. Using transparent partitions in the place of opaque walls can provide some benefits, the biggest of which being that lab processes can be observed, whether by compliance regulators or supervisors within your organization, without disturbing cleanroom processes or the environment within.

 

Flexibility

Many organizations are resisting the use of specific dedicated spaces for certain tasks or operations, instead opting for more shared spaces and flexibility in order to reduce costs and under-utilized space. This means incorporating fixtures and furniture, such as lab benches and workstations, into your cleanroom that can accommodate a variety of tasks or processes, as well as modular cleanrooms that can be easily expanded, contracted, or reconfigured to maximize use of space.

 

As you’re working on your cleanroom design or redesign, consider the needs of your company and your cleanroom, as well as how the cleanroom can continue to meet those needs over time, with organizational and regulatory changes. Incorporating sustainability, transparency, and flexibility into your cleanroom design can make your cleanroom efficient and future-proof, not matter the changes to come.

Looking to design a new cleanroom? Get in touch with the cleanroom experts at Angstrom Technology.

Benefits of Cleanroom Pass-Through Chambers

Pass-through chambers are a commonly used cleanroom term, and they’re also an ideal addition to just about any cleanroom. They’re easy to install, they don’t draw much out of your budget, and they hold tons of benefits for the operation of your cleanroom. While there are all types of pass-through chambers, from basic transaction windows to industrial roll-up door pass-throughs, most cleanroom pass-throughs fall into the dual-door category. Because the removal of contaminants is any cleanroom’s top priority, most cleanroom pass-through chambers have two doors, one on the outside and one on the inside of the cleanroom. Those cleanrooms that must meet higher standards often install pass-throughs with additional features like an air shower or fire resistance, but the general construction and operation is the same.

What are the benefits of cleanroom pass-through chambers?

  • They allow your employees to transfer materials in and out of your cleanroom without contamination.
  • They make it easy for employees to pass materials into the cleanroom without having to gown. This also cuts down on the number of employees in your cleanroom at any one time.
  • They come in a variety of sizes and materials, ensuring you get the pass-through that meets the needs of your employees. Stainless steel options are corrosion-free, which extends the life of your pass-through, and helps keep your cleanroom clean.
  • Double door designs ensure cross contamination doesn’t happen. And heavy duty sealing lock features keep contaminants out of the chamber when it’s not in use.
  • Most pass-through chambers are customizable, allowing you to choose the option that best fits the needs of your cleanroom. Whether you need a fire safe option, one that’s chemical resistant, or a pass-through chamber that includes a blower with HEPA filtered air, you can choose the chamber that best suits your cleanroom needs, ensuring you benefit from a pass-through chamber, regardless of your cleanroom classification.

How do cleanroom pass-through chambers increase productivity?

The single greatest benefit of a cleanroom pass-through chamber is its ability to speed up your processes and increase employee productivity. Pass-through chambers eliminate the need for employees to properly gown to enter a cleanroom environment just to hand off a necessary item or sample. As you likely know, the gowning process can be time-consuming, and additionally, the more employees you have in a cleanroom, the greater the chance for contamination. When employees can simply place materials in the pass-through chamber, you save a great deal of time on both sides of the cleanroom. Best of all, pass-through chambers are easily installed, whether you have an existing cleanroom or you’ve just commissioned a new one.

Who uses pass-through chambers?

The benefits of pass-through chambers are clear. They boost productivity without sacrificing cleanliness. So, which cleanroom industries use pass-through chambers, and how?

Research Facilities

Because research facilities often study new and unpredictable chemicals and substances, they need pass-through chambers for safety more than for convenience. Because some chemicals can easily become volatile and cause fires, fire safe pass-throughs are commonly used in this application. These pass-through chambers can withstand fire exposure for up to 90 minutes, and their sturdy construction maintains frame shape that protects research labs from destruction. While these labs also often make use of air shower pass-throughs to decontaminate materials before they’re introduced to the lab, fire safe pass-throughs are the most common.

Medical and Pharmaceutical cleanrooms

Decontamination is the first priority of both medical and pharmaceutical cleanrooms. Because hospital laboratories often deal with highly contagious substances, it’s paramount that the environment remains sterile. In the same vein, pharmaceutical cleanrooms have to ensure there is absolutely no contamination in the manufacturing process that could alter their product. In both cases, these cleanrooms require pass-through chambers that keep samples, specimens, and other materials sterile as they’re brought into the cleanroom. These industries typically make use of a standard two door pass-through chamber that keeps outside contaminants from entering the cleanroom and ensures the materials remain sterile as they’re waiting to be brought in.

Electronic and technology manufacturing cleanrooms

Manufacturing facilities that put together the complex inner workings of technological devices like computers and smartphones require very strict cleanroom environments that filter out even the smallest particles of dust and other contaminants. Just one tiny particle settling on a single piece in the manufacturing environment could render a future hard drive useless. Many electronic and technology manufacturing cleanrooms opt for highly monitored pass-through windows in order to maintain the sterility necessary to produce quality electronic products while maintaining a high level of productivity.

 

Pass-through chambers are a highly useful component of any cleanroom. They help you ensure that you keep your processes moving, while maintaining the high standard of cleanliness within your cleanroom. If you’re installing a new cleanroom, or even if you’re considering adding a pass-through chamber to your existing cleanroom, be sure to give the experts at Angstrom Technology a call! We’ve been manufacturing top-of-the-line cleanrooms for years and would be more than happy to help you find the pass-through best for your operation. Call our office at 888-768-6900 or contact us online today!

What You Need to Know About Cleanroom Classifications

What You Need to Know About Cleanroom Classifications

If you’re installing a cleanroom within your company for the first time, all of the information associated with the process can be a bit overwhelming. There are a whole variety of new terms, you have to decide where to put your cleanroom, how big to make it, how to do it all on budget, and what’s worse: you have to figure out what standards to adhere to. Cleanroom classifications are one of the most confusing parts of cleanroom construction. If it’s your first time commissioning one, it can almost seem like dealers are speaking another language, and no one makes it quite clear what a cleanroom classification really means. We thought we’d take a minute to explain what goes into cleanroom classifications and standards, so you have a better idea of what you’re working with when you get to commissioning your cleanroom design. Here’s everything you need to know about cleanroom classifications, from deciding what standard to adhere to, to figuring out how to do it cost-effectively:

What’s your application?

The very first thing to know about cleanroom standards is which one is required for your application. Every industry has different requirements and needs, from electronics manufacturing to food preparation, and some are more strict than others. It’s important that you know exactly which classification is required of your industry, because if you install a cleanroom that’s designed to the wrong specifications, you’ll either be spending too much money on an overpowered cleanroom, or your product will suffer from the excess contamination. If you’ve been contracting with a private firm for a while, or if your industry is regulated by a government agency, it’s a good idea to check with them to see what classification you should design your cleanroom for. They’ll have documentation on the standards their labs function to, and should be able to give you plenty of information regarding what’s necessary, what’s recommended, and what you don’t need to worry about when designing your own cleanroom.

What’s a cleanroom classification?

Cleanrooms are classified by the number of contaminants that exist in a functioning cleanroom. Contamination is measured in parts per cubic meter.  Say, for example, that your cleanroom has to measure up to an ISO Class 6 level, which is rated at 35,200 parts per cubic meter. This means that within your cleanroom, you can have no more than 35,200 particles greater than .5 microns in size, per cubic meter of cleanroom space.  For reference in size, the typical measurement for the end of a piece of human hair can be anywhere from 60 to 100 microns in size. A particle that’s as small as .5 microns in size cannot be seen by the human eye, which is why we need high-quality filters to contain them.

ISO standards

The current accepted standards for cleanroom classifications are ISO (International Standards Organization) standards. This is the classification system most widely accepted internationally, and the U.S. just switched to this standard officially in 2001. It’s likely that while you’re doing research on your new cleanroom, you’ll come across a classification called the Federal Standard 209E, which was the previous accepted American standard for cleanrooms. These federal standards were officially cancelled in 2001, but many people in the industry still reference them. It’s just important to know that in today’s world, your cleanroom will have to measure up to a certain ISO standard, rather than a federal one.

There are nine ISO classes: Class 1 (the cleanest) to Class 9. The lower the ISO class rating, the cleaner the environment. ISO standards created three new classes that the Federal Standard did not address, making it the more comprehensive classification system. It’s best to refer to ISO whenever possible, because it’s internationally recognized and will limit any confusion. Here’s a better look at what each ISO Class looks like, as well as how they measure up to the old Federal Standards:

ISO 14644-1 Cleanroom Standards
Class maximum particles / m3 FED STD 209E

equivalent

≥0.1 µm ≥0.2 µm ≥0.3 µm ≥0.5 µm ≥1 µm ≥5 µm
ISO 1 10 2.37 1.02 0.35 0.083 0.0029
ISO 2 100 23.7 10.2 3.5 0.83 0.029
ISO 3 1,000 237 102 35 8.3 0.29 Class 1 Cleanroom
ISO 4 10,000 2,370 1,020 352 83 2.9 Class 10 Cleanroom
ISO 5 100,000 23,700 10,200 3,520 832 29 Class 100 Cleanroom
ISO 6 1.0×106 237,000 102,000 35,200 8,320 293 Class 1,000 Cleanroom
ISO 7 1.0×107 2.37×106 1,020,000 352,000 83,200 2,930 Class 10,000 Cleanroom
ISO 8 1.0×108 2.37×107 1.02×107 3,520,000 832,000 29,300 Class 100,000 Cleanroom
ISO 9 1.0×109 2.37×108 1.02×108 35,200,000 8,320,000 293,000 Room air

(µm denotes micron particle size)

*Chart courtesy of PortaFab

Know how standards apply to your cleanroom’s 3 different states

So now you know what classification your cleanroom has to adhere to, it’s important to understand how that is measured by inspectors. Basically, your cleanroom has three different states: As built, at rest, and operational. The first refers to how your cleanroom performs just after it’s built–without furniture, employees, equipment, or machinery. Cleanroom certifications for cleanliness given by manufacturers refer to this as built state. At rest is your cleanroom once you have all of your equipment moved in, but before your processes are up and running. At this point, the workers have yet to move in, but your supplies and machinery are likely creating a bit of contamination just sitting in your room.

The third state refers to your cleanroom once you’re finally running processes with employees. This is going to change the level of contamination within the cleanroom the most, as people tend to shed a multitude of particulate, and machinery can often cause disruptions in airflow and give off contaminating fumes. It’s important to understand that once you get everything working, you’re going to have more particulate circulating your cleanroom than what your cleanroom standard calls for. Keep this in mind as you begin designing your ideal cleanroom, and make adjustments to allow for the extra particulate that will inevitably contaminate your cleanroom once you get people and machines moving.  

Understand how a cleanroom works

Now that you know what the classifications are and how they’re measured, we’ll dive into how you get your cleanroom to meet those standards. To do that, it’s important to know how cleanrooms function. The great majority of cleanrooms exist on a positive pressure method. That means that air is pumped into the room through high-powered HEPA filters that remove the necessary contaminants. The air then flows down, and is pushed out through vents in the floor. The idea here is that any particles that exist in the cleanroom are forced out of the room by flowing air. Because positive pressure cleanrooms have higher air pressure than the rooms surrounding them, air flows from the cleanroom into the other rooms, which forces contaminated air from other rooms back, and away from the cleanroom.

In positive pressure clean rooms, air is constantly flowing out of the room. It’s good to know that negative pressure cleanrooms do exist, but they’re far less common. Negative pressure cleanrooms function exactly opposite of positive pressure cleanrooms, and are meant to contain dangerous contaminants like infectious diseases or hazardous substances. Air is pulled in from other rooms, is filtered within the cleanroom, and returns to the outside as clean, contaminant free air.

So how do you build a cleanroom that adheres to the proper classification?

In most cases, it all comes down to air. Most cleanrooms are structurally very similar: they feature return air grills, airtight walls, doors, and windows, and they basically function to keep clean air in, and contaminated air out. To achieve a cleaner class of cleanroom, it really all comes down to airflow. Any time you move down one class, you require about twice as much air. This is because the air is what does most of the work of ridding the space of contaminants. This is also the biggest cost associated with cleanrooms, because to get proper airflow in a cleaner class of cleanroom, you need more filters, more air return space, and generally just more air to be pumped into the space. The cleaner you need your environment to be, the greater the rate of air change.

Class Average Airflow Velocity Air Changes/HR Recommended
ISO Class 8 Not applicable 10-20 20 to 40
ISO Class 7 Not applicable 30-70 50 to 80
ISO Class 6 Not applicable 70-160 100-180
ISO Class 5 .2-.5 m/sec (40-90ft./min) Not applicable 300-400
ISO CLass 4 .3-.5 m/sec (60-90ft./min) Not applicable

*Chart courtesy of Simplex Isolation Systems

For lower classes of cleanrooms, ISO class 9 through class 6, cleanliness is based on the amount of air changes that happen each hour. Cleanrooms that have more stringent cleanliness requirements–Classes 5 through 1–measure the flow of air through the room in meters per second. So how fast is that air moving through the room, how is it getting out, and when the air leaves the room, is it taking contaminants with it?

This is where a cleanroom designer comes in handy. Even if you create the perfect cleanroom with top-of-the-line technology, improperly placed equipment and furniture can create dead spaces where particulates are blocked from the air flowing through the room. When this happens, more particles are sticking around in your cleanroom, messing up your processes, and potentially hurting your workflow and production abilities.

We hope this blog helps shed a bit of light on the confusing world of cleanroom classifications! If you have more questions about designing your new cleanroom to the necessary standards, be sure to get in touch with the experts at Angstrom. We’ve been designing and installing cleanrooms across the country for years now, and would be happy to help you out! Request a free quote online today, or give our office a call at 888-768-6900.