Cleanroom Doors: How to Choose ISO-Compliant, Airtight Solutions for Maximum Protection

As its name implies, a cleanroom is a controlled environment that needs to stay perfectly clean. Cleanrooms are built to house very sensitive activities relating to research, manufacturing, product development, and more. These tasks require an extremely low level of particulate matter in the air. Any particulates like dust could compromise the activities being done in the cleanroom.



Cleanrooms are built to exacting standards to keep out any of these undesired particulates. Choosing the most appropriate cleanroom door system is an important part of your cleanroom design. The door is the cleanroom’s main access point to the outside world, so it must be built to allow people and equipment to enter the room and at the same time keep any dust and other particulates out of the room. 

Here are the criteria should consider when you select the appropriate doors to ensure that your clean room door won’t compromise your activities:

Know How Much Particulate Matter is Acceptable

Not all cleanrooms perform the same tasks. Before you select a cleanroom door, you need to know how tightly controlled the cleanroom environment will be. This requires a detailed knowledge of how much particulate matter is acceptable in the cleanroom design. Essentially, the less particulate matter, the more extensive the door type will need to be.

ISO 14644 standards rank cleanrooms from ISO 1 (ultra-clean) to ISO 9 (least stringent). For most industries, ISO 7 and ISO 8 are sufficient, but if you’re handling sensitive electronics or pharmaceuticals, you may need ISO 3 or ISO 5 standards.

The particulate limit will determine the level of sealing, speed, and material requirements for your cleanroom door.

Tight Sealing is the First Line of Defense

Think of a door seal like a Ziploc bag — it’s got to snap shut every time to keep contaminants out. If your cleanroom doesn’t form a tight seal when shut, then it will be useless. 

Many cleanroom doors are built with double-gasket design to ensure a tight shut. The door needs to form a tight seal at the top, bottom, and both sides. The seal needs to be completely airtight, which is why you need to buy a door that was specifically designed for this task.

For best results, look for these features:

• Double-gasket seals for all sides of the door.
• Fast-closing mechanisms to reduce air turbulence.
• Doors specifically designed for ISO compliance.

Quality Materials and Hardware: Aluminum, Stainless Steel and Glass

The first thing to look for in a cleanroom door is that it is made from quality materials. This includes the door itself and the materials affixing the door to the cleanroom wall system. The materials need to be strong and thick (recommended at least 60mm thick). This is not only to keep particulates out, but to ensure they can stand up to the rigors of an industrial environment and won’t break or bend.

The ideal cleanroom door:

• Is made of aluminum or stainless steel.
• Features glass panels for easy cleaning and durability.
• Minimizes crevices and cracks where dust or microbes can settle.
• Incorporates antimicrobial coatings for added protection.

Speed and Automation: Open Fast, Shut Faster

Another factor to consider is how quickly you can open and close the door. Many cleanroom doors need to open for very short periods to ensure that no outside contaminants have the chance to enter. For this reason, many cleanroom doors are built with fast-sliding doors, which form a tight seal when shut. Alternatively, some doors operate automatically, which makes sure the door is never open for too long and always shuts properly.

Time is of the essence in cleanroom design. The longer a door stays open, the greater the risk of contamination.

• Sliding doors with fast-gliding technology are ideal.
• Sensor-activated doors open only when necessary, minimizing human error.
• Adjustable speeds are useful because not all cleanrooms operate under the same conditions.

Compliance with ISO and FDA Standards

For industries like pharmaceuticals or food processing, FDA’s Current Good Manufacturing Practices (cGMP) are non-negotiable. Horton’s UltraClean™ door systems, for example, meet ISO 3 and ISO 5 classifications, ensuring regulatory peace of mind.

Locking and Security Integration

Cleanroom doors often handle more than contaminants; they also protect sensitive equipment and data. Therefore it’s important that the cleanroom door integrates into your security system as a whole and works with your existing access privileges. For example, if your business operates on a key-card system, then you’ll want to be sure the door is compatible. Whatever locking mechanism you choose for the door, it’s most important that you provide access to the right people. 

Ensure compatibility with security systems like:

• Key-card readers.
• Access control panels.

Flat Cleanroom Door Surfaces are Easy to Clean

This feature is often overlooked by buyers of cleanroom doors. It is important that the door has a flat surface, including where it connects to the wall and if there are any windows installed. This is because the door needs to be easy to wipe clean. If the door has any indentations, then it’s possible for dust to gather unnoticed. A flat door lessens this possibility and makes it much easier to wipe clean.

Here’s why flat doors are essential:

• They’re easier to disinfect.
• They prevent dust buildup in cracks and crevices.

Proper Installation

Finally, you need to be sure the door is properly installed so it’ll fit perfectly with the door frame, ensuring a tight fit when shut. This is why we recommend you contact a professional to handle this process. They’ll install the door so it blends seamlessly with your cleanroom and performs its intended function. No  matter the quality of the door, it won’t work properly if it’s installed improperly. 

Different Types of Cleanroom Doors

There are many types of cleanroom doors, each with their own advantages and disadvantages. It’s important to choose the style of door that is best suited to the tasks being done in your cleanroom. Here’s a quick overview of the types of cleanroom doors:

Sliding Door

Sliding doors are uniquely suited to cleanroom environments. Their design allows them to sit flush against the wheel, forming a tight seal when shut. These doors are also able to slide open and shut quickly, which minimizes time spent exposed to the outside environment. However, these doors tend to be quite expensive to install, particularly if you want to give them “automatic” functionality.

Swing Door

The most “basic” type of cleanroom door, and often the most affordable. Swinging doors operate by swinging in or out and form a tight seal when shut. These doors hold cost advantages, but often can’t open and shut as efficiently as other doors on our list.

“Pass-through” Doors

Not quite a cleanroom “door,” but an intuitive solution for getting materials in and out of the cleanroom. A pass-through is a compartment surrounded by two doors, connecting the cleanroom to the outside environment. An object is placed in the compartment, shutting the door behind it. Then, someone inside the cleanroom can open the opposite door, receiving the object. A sanitary way to get equipment or materials in and out of the cleanroom.

Horton UltraClean™ Solutions: Meeting ISO 3 to ISO 5 Standards

For industries demanding the highest standards, Horton UltraClean™ Atmospheric I & II doors deliver unmatched performance.

UltraClean™ Atmospheric I

• Meets ISO 3 requirements.
• Available in single-slide configurations.
• Perfect for pharmaceutical and high-precision environments.

UltraClean™ Atmospheric II

• Designed for ISO 5 cleanroom standards.
• Single and bi-parting sliding options.

Shared Features:

• Customizable dimensions for width (up to 16’) and height (up to 7’6”).
• Durable materials: Glass, stainless steel clad, and anodized options.
• Adjustable speeds to reduce air turbulence.
• Tested for 1,000,000 cycles with a reliable 2-year warranty.

Horton’s cleanroom doors not only meet stringent standards but also simplify maintenance and enhance operational efficiency.

Conclusion

Cleanroom doors are vital for maintaining a contaminant-free environment. Selecting the right door involves assessing particulate requirements, ensuring quality materials like stainless steel, tight seals, and smooth surfaces for cleanliness.

Horton’s UltraClean™ solutions offer industry-leading performance, ensuring your cleanroom meets ISO standards without compromise.

Please contact us for more information.