27 Nov Cleanroom Airlocks: A Simple Guide to Their Purpose and Use

Whenever a person or object enters or exits a cleanroom, there’s always the risk of contamination. Controlled environments are delicate, and organizations that use them must be extra careful to protect the processes happening inside. Airlocks happen to be one of the best ways to mitigate this risk, which explains why they’re so often used in these environments. In this article, we’ll explore what cleanroom airlocks are, how they work, the different types, and more.

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What is a Cleanroom Airlock?

A cleanroom airlock is an enclosed space with two or more interlocked doors. These airlocks are used to minimize contamination when moving people or materials between cleanrooms and adjacent spaces. Their interlocks prevent both doors from being opened at this same time, which can cause cross-contamination.

The main purpose of a cleanroom airlock is to do one or more of the following:

• Control Contamination: As we mentioned already airlocks prevent contamination between spaces.
• Control Environmental Conditions: Airlocks can also help maintain conditions such as temperature, humidity, and pressure. Cleanrooms need to keep these stable so that they remain compliant with relevant standards (ISO, USP 797/800, FDA, etc.).
• Control Access Between Spaces: They can also be used to restrict access to vulnerable or dangerous areas.

How Do Cleanroom Airlocks Work?

As we explained above, airlocks create a type of buffer space that helps prevent contamination from passing between two or more spaces. Here are a few of the basic features of modern airlocks:

Two-Door System & Security Features

An airlock usually consists of two doors: one leads into the external environment and one leads into the cleanroom. These doors are electronically interlocked, meaning only one can open at a time. This prevents personnel from accidentally having both doors open.

There are other security measures that may be added, such as secure airlocks, where a request is needed to open the door, by way of a fingerprint, button, keypad, or some other device. Also, airlocks may be supervised, which means a person monitors access, often through a viewing panel or CCTV, and approves entry requests manually. These are just a few of the many ways airlocks can have extra security.

Pressure Differentials

Cleanrooms often need to keep higher pressure than surrounding areas to push particles outward rather than letting them in. When personnel enter an airlock, the pressure differentials can help keep contamination at bay.

Often, the airlock is at a slightly lower pressure than the cleanroom, but higher than the outside environment. This creates a cascading airlock effect where (in the case of a breach) air would flow out of the cleanroom and into the outside environment. This effect prevents air from flowing into the cleanroom and bringing particles with it.

There are other types of pressure differentials used in airlocks, depending on what type of work is being performed in the cleanroom. For example, bubble airlocks have the highest pressure inside the airlock itself, which pushes particles back into their respective areas. This may be useful in situations where both the cleanroom and the adjacent areas need to avoid cross-contamination.

On the other hand, sink airlocks keep lower pressure inside the airlock, drawing air inward from adjacent spaces to trap particles. For example, in a lab working with infectious diseases, they may be useful in trapping contaminated air inside so it doesn’t escape into other rooms.

Environmental Controls

Additionally, airlocks will often have systems to match cleanroom conditions, such as HEPA filters, to help remove particles. The purpose of this is to make sure that entering air is clean enough to meet the standards required by the cleanroom. They may also control temperature, humidity, and pressure.

Personnel Procedures

In many cleanrooms, airlocks act as a gate that personnel use to get ready. In this context, they are called gown rooms, because it’s where they put on their cleanroom suits, gloves, shoe covers, etc. Also, some airlocks have air showers that use high-pressure air to blow off any particles before they go inside.

Common Types of Cleanroom Airlocks

Cleanroom airlocks may come in a few different types, each of which is designed for a specific purpose. Here are the two most common types of airlocks in cleanrooms:

Personnel Airlocks (PALs)

These airlocks govern the movement of people entering and leaving clean spaces. As we mentioned above, many of these airlocks double as gowning rooms.

Material Airlocks (MALs)

Material airlocks, on the other hand, are just what they sound like. Airlocks designed for transferring materials in and out of cleanrooms. When they are much smaller, about the size of the box, they are called pass-through chambers. But the function of each is essentially the same.

The Bottom Line

Cleanroom airlocks are important for preventing cross-contamination, controlling environmental conditions, as well as managing access to important areas. By understanding their purpose, how they work, and the types available, you can choose the best solution to help protect your cleanrooms and surrounding spaces.

Interested in adding cleanrooms with airlocks to your location? Reach out to the experts at Allied Cleanrooms and get a quote on new controlled environments today.