The design of a cleanroom door may make it suitable for an application, but it relies on documented independent testing to be certified for the facility’s classification. True certification relies on compliance with ISO 14644-1, which classifies air cleanliness by airborne particle concentration across nine classes, with the correct class determined by the facility and its processes.

If you’re specifying a door for a new cleanroom or facility upgrade, that classification determines the validation evidence you need for the project. Using the EFAFLEX CR Series supplied and installed by Premier Door Systems as an example, we explain what ISO Class 5 and ISO Class 6 certification confirms, how it relates to the wider cleanroom and how the three models compare.

What Does ‘Cleanroom Certified’ Mean?

A cleanroom-certified door has undergone stringent independent testing and passed the requirements for a stated cleanroom classification. For a project team, it provides documented evidence that the door system has been tested and the relevant ISO class has been achieved to use during the specification.

Certification is also only part of the compliance process. ISO 14644-1 classifies the air cleanliness of the entire cleanroom environment, with a certified door supporting the environment. The completed cleanroom must still undergo its own testing and validation to be compliant. 

Cleanroom-Certified Versus Cleanroom-Suitable: Why the Distinction Matters

However, certification and suitability are two distinctly different things, and something to be cautious of in the specification process. 

Term	What It Means	Evidence to Check
Cleanroom-suitable	Its design and performance characteristics may suit a controlled environment	Product specifications covering sealing, material, cleanability and pressure resistance
Cleanroom-certified	The tested door system has documented performance for a stated cleanroom classification	Independent certificate or test report identifying the model, standard, ISO class and test conditions

Understanding ISO Class 5 and ISO Class 6

ISO Class 5 and ISO Class 6 are both air quality classifications under the ISO 14644-1 standard. The lower the class, the stricter the airborne particle concentration limits, with an ISO Class 5 ten times cleaner than ISO Class 6.

What classification is required to meet the level of cleanliness depends on the type of pharmaceutical facility, process and applicable Good Manufacturing Practice requirements (GMP), regulatory or quality requirements. Once the classification is determined, the selected door must carry certification for that class where certified performance is specified. For example, an ISO Class 6 door cannot satisfy a specification requiring ISO Class 5 certification. 

What Should You Look for in a Cleanroom Door?

Every time cleanroom doors are opened, they introduce potential risks between controlled zones. To reduce the risk, every door cycle must be able to restore the separation, with the contributing factors attributing to the door’s suitability for the specific application. 

Sealing and Pressure Control

When a door to a critical environment is closed, the sealing should limit unwanted air exchange and support the pressure differential between the adjoining zones. To establish suitability for an individual opening, compare the documented door performance and rated capabilities with opening’s pressure, traffic, cleaning and control requirements.

High-Speed Operation

Every time a door opens, air and airborne particles have an opportunity to pass-through the cleanroom. High-speed doors limit this time, measured by their opening and closing speed, hold-open time and activation method to determine the potential contamination exposure in a complete cycle. 

Hygienic and Cleanable Design

To support hygiene, the cleanroom door itself should not create areas where contaminant particles or residue can accumulate between open-close cycles. This is why hygienic and cleanable designs should include smooth, seamless surfaces, minimal joints and protruding edges, accessible seals and materials that can tolerate the facility’s cleaning agents and methods without deteriorating.

Durability and Operating Cycles

Each of these factors should also remain consistent across a door’s service life. To determine suitability, compare the door’s rated operating cycles with the expected traffic, also reviewing the durability of any curtains, guides, seals, hinge mechanisms and drive systems along with maintenance access and servicing requirements.

Airlock and Interlocking Requirements

If the opening forms part of an airlock or material lock, the door must also operate as part of a connected control sequence. Premier Door Systems recommends confirming its interlocking capability, access control integration, emergency release and response to a power or control failure so any adjoining doors do not open simultaneously. 

How Does the EFAFLEX CR Series Compare?

Something that is clear from our 40+ years in cleanroom door solutions at Premier Door Systems is that even a certification match may still not meet the opening specifications, like speed and cycle capacity. With three independently certified models, the EFAFLEX CR Series can meet different classifications and suitability requirements.

Model	Classification	Opening Speed	Operating Cycles	Best Suited To
EFA-SRT CR Premium	ISO Class 5	Up to 1.0 m/s	Up to 150,000 per year	Highly controlled environments with stricter particle control, effective sealing and airlock capability requirements
EFA-SRT CR Efficient	Up to ISO Class 6	Up to 0.8 m/s	Up to 100,000 per year	Class 6 applications requiring an almost airtight door with a slim frame
EFA-STT CR	ISO Class 6	Up to 2.5 m/s	Up to 200,000 per year	Larger or high-traffic openings requiring pressure resistance, visibility and rapid operation

Each model features an almost airtight construction and smooth, cleanable surfaces required for controlled zones. The EFA-STT CR also adds a door leaf made from 70% transparent acrylic glass to allow visibility between adjoining areas. During planning, each model’s headroom and side clearance, wall interfaces, power supply and control connections should be accounted for to determine suitability for each opening.

Verifying Cleanroom Door Certification Compliance

Before a cleanroom door is approved, it’s important the certification applies to the exact system being proposed. To enable this, the supporting certificate or test report should clearly identify:

• The independent testing or certification body used
• The exact door model and tested configuration
• The application standard, including ISO 14644-1
• The ISO class achieved
• The scope and conditions of the testing
• Any size, construction or installation limitations
• The certificate or report number and its issue date

Specifying the Right Cleanroom Door

A cleanroom door can carry the required ISO classification for a project but still not be suitable if its speed, sealing, cycle capacity or controls don’t suit the opening and its purpose. To consider both sides, the final specification should align the certification for the exact model with the room’s pressure conditions, traffic, cleaning regime, dimensions and interlocking requirements.

Compare the certification models within the EFAFLEX CR Series or explore Premier Door Systems’ broader range of clean room doors designed for controlled and sterile zones, including high-performance automatic doors for high-traffic openings, sliding door systems and hygienic swing doors.

Planning a new cleanroom application or facility upgrade? 

Speak with Premier Door Systems about your cleanroom door requirements.