Types and Requirement of Airlocks in Controlled Areas. Learn about the types and requirements of airlocks in classified areas during pharmaceutical manufacturing.

Types and Requirement of Airlocks in Controlled Areas

Learn about the types and requirements of airlocks in classified areas during pharmaceutical manufacturing.

Airlock helps to protect the classified area from the contamination that may occur during the entry and exit of personnel and material.

Airlocks are closed rooms having two or more doors between two different controlled areas having different cleanliness levels as class B and class C, class C and class D areas. These airlocks prevent the direct air flow between these areas during the entry of material or personnel. Airlocks are called PAL (Personnel Air Lock) when used for personnel and MAL (Material Air Lock) when used for transferring the material.

Related: Clean Rooms and Controlled Areas (Sterile Area Classification)

There are three types of airlocks:

A. Cascade Airlock

B. Bubble Airlock

C. Sink Airlock

A. Cascade Airlock: These airlocks are very common having higher pressure on one side and lower pressure on another side. This prevents to enter dust and contaminants from outside to airlock and from airlock to inner side.

B. Bubble Airlock: These types of airlocks have higher pressure inside the airlock and lower pressure in both outsides. This prevents the flow of air between two areas through the airlock creating a pressure barrier.

C. Sink Airlock: Airlocks having lower pressure inside the airlock and higher pressure on both sides of the airlock. This airlock pulls air from both adjacent areas creating a low pressure barrier.

Doors of the airlocks should open to higher pressure side; it will help to close the door.  An interlocking system should be provided to prevent the opening of both doors at a time. An alarm should be provided to indicate that one door is opened. It helps to prevent the entry of contamination through the airlocks. Higher air changes per hour rate should be maintained in the airlock, it should be minimum 20 air changes per hour. It helps to remove the contaminants entered from the outside easily.

Airlocks should be kept empty, material such as garments, shoes covers etc. should not kept in the airlocks. I have observed it many times in pharmaceuticals keeping these articles in airlocks.