Hazardous area pharma clean room

Considerable investment has been made by Daw Technologies in the development of a new type of clean room.

Specially designed to cope with environments handling volatile pharmaceuticals and APIs, the trigger for this advance was made when the company was approached by Rhodia Chirex, which had recently decided to extend the scope of its pilot plant for the introduction of new ethical pharmaceutical products.

Daw Technologies is well known for its modular clean room designs, especially in the semiconductor sector.

However, Rhodia needed to upgrade a suite which, although designed with a future capacity for active pharmaceutical ingredients (API), began operation with a throughput of intermediates and hence, a lower classification standard.

Steve Revill, Rhodia's senior project engineer explained, "At first we felt that we could handle this project in-house, but cost constraints proved to be a factor, so we asked several companies to come up with some ideas.

Despite the fact that Daw had less experience in the pharmaceutical sector than the other companies we talked with, it was nevertheless the clear winner. It was felt that this was the only company which had a real commitment to supplying the CGMP documentation to demonstrate the quality of the build and validate it for its intended use.

The Daw design also managed to incorporate into the clean room the building's heating and ventilation system, which immediately reduced the installation cost by 30%." There were three technical challenges.

Firstly, as with all other equipment on site, the new clean room and all its associated services needed to be able to fulfil the hazardous area electrical classification requirements.

Secondly, the pre-existing offloading facility needed to be incorporated.

This entailed erecting a class 10,000 clean room around the batch production vessel filling equipment. Finally, the validation had to meet standards approved by international regulations.

The two companies worked in partnership throughout the final stages of the design, the part specification and the creation of the documentation for the validation.

An illustration of the sometimes conflicting demands of a good clean room environment within a hazardous environment, was most keenly felt on the electrical side of the design.

The two companies worked especially closely to ensure that the safe change filter housings and fan filter units (FFU) met all the criteria.

The standard Daw FFU was developed in order to meet the strict EXD ratings which demand that no sparks are capable of being generated.

The lights for the clean room both had to conform to Rhodia's hazardous area site standard and maintain clean room pharmaceutical integrity.

The new clean room is broken down into four different zones: the offload area which boasts two airlocks at the entrance and the exit, the key handling area, the air suit change area, and dirty change area. Throughout the system is high pressure, Hepa filtered air.

This air is maintained at a high pressure throughout, so as not to draw any outside air through any inlets.

In the offload area, where air purity is of very great importance, the air is pressurised at 45 pascals.

This declines to 15 pascals in the dirty change area.

All the air that enters the clean room is first filtered through terminal Hepa filters.

All the air for both the clean room and the separate heating and cooling system is taken from the building.

Similarly, the respiratory air also incorporates a pre-existing system which penetrates the clean room via a continuous liner.

This liner, which cannot be penetrated, protects the air en route to the respiratory air kegs.

Rhodia's pharmaceutical customers expect very stringent standards to be enforced, so the clean room has certificates proving the quality to every element, from the panel paint to the transfer hatches.

Each of the three stages, the design, installation and the operation of the clean room has a fully documented qualification.