The environment is strictly controlled in pharmaceutical manufacturing plants to avoid microbiology and dust. Airlock and interlock are essential to prevent contamination and cross-contamination between different clean zone in factories.
What is interlock?
In factories, the airlock is an intermediate room to separate and ensure that the atmosphere between 2 rooms/areas (with different levels of cleanliness) does not mix together. For the airlock to work, a device that controls the opening/closing of the door, called an interlock, is required. In addition, the doors can be equipped with an interlock system in clean rooms with multiple doors or interconnecting rooms. This system helps prevent sudden loss of positive pressure and airflow when staffs inadvertently open too many doors at once, which can cause cross-contamination.
Where can interlock be used?
Interlock can be used in factories, manufacturing companies, laboratories, sterile rooms, or vacuum chambers to reduce the amount of outside air entering the room or vice versa when going in and out of the room.
Types of interlocks
- Soft interlock
Soft interlocks are simple and inexpensive. They are employed in areas/rooms where the environmental criteria are less strict. In many cases, the door is only equipped with a window or a visual indicator (light signal, sound, etc.) so that the user can identify and decide whether to open the second door. The operation of a soft interlock requires human consciousness and discipline, as there is no automatic mechanism.
- Hard interlock
Unlike soft interlocks, hard interlocks have 2 doors equipped with electronic devices (usually electromagnets) to ensure automatic control of the opening/closing of the door. Rigid interlocks can be retrofitted with visual indicators or windows.
In addition, the interlock is also divided into 2-door, 3-door, or 4-door systems. The common point is that only 1 door can be opened at a time.