Humidity in pharmaceutical Cleanroom Walls after a Leakage

In the event of a leak in the cleanroom ceiling area, pharmaceutical cleanrooms are extremely vulnerable. Water ingress, e.g. due to leaking pipes, operating errors e.g. with hoses or rain ingress via the building roof, is relatively common. The number of possible individual risks is very high.

As system owner, you are often in a dilemma in the event of damage. Among other things, there are real risks to the quality of the medicines due to mold growth or similar in the walls and on the coving on the floor. Technical risks arise from possible corrosion or electrical short circuits.

What can be done?

It is often not possible to clearly define the extent of the damage (what has become wet). Many cleanroom ceiling constructions intensify the problem because liquids are distributed over more than 100 m through U-profiles and entries into the cleanroom walls at the top (e.g. for cables or pipes) are generally not sealed. With many cleanroom wall constructions, there is no quick and easy way to repair the damage (e.g. filling with mineral wool or prepared plasterboard walls) - so that the question often arises as to whether entire walls need to be replaced. The following measures are often sufficient after a leak in the cleanroom ceiling area:

• Stop production and set the ventilation system to maximum air exchange with minimum humidity
• Determine the extent of the leakage: e.g. by locally removing covings between the wall and floor or using endoscopes via locally dismantled socket openings
• Removal of residual water with water extractors to remove puddles and residual water from cavities.
• Use of hot air blower or dry compressed air to accelerate drying.

Insurance considerations and risk assessment

Leakage incidents during the construction phase or caused by external parties can lead to insurance claims. Due to production downtime and the need to repeat microbiological and particle monitoring, the amounts of damage can quickly run into several million euros/dollars, etc.
In the hectic rush, claim adjusters with pharmaceutical or cleanroom knowledge are usually not found at short notice. This can quickly lead to a worsening of the damage. A "classic" in this context is the panicked installation of dozens of construction dryers in the cleanroom. However, typical construction dryers with condensers are not suitable for cleanrooms. The existing air conditioning system with the high air exchange rates that are usual for cleanrooms is generally more efficient and faster for drying the rooms.
The often hasty replacement of walls is also often not necessary.
A moisture test is recommended for drywall plasterboard walls:

• < 80%: The wall is not considered damp.
• 80-100%: The wall is damp.
• > 100%: The wall is wet.

Damp and wet walls can often be remediated faster and better using the methods described above (e.g. within 5 days) than would be possible by replacing the entire wall (often takes 1-2 months).

Conclusion

The protection of cleanrooms against leaks is often neglected in the planning and construction of new pharmaceutical production facilities. Many projects are caught out during the construction or commissioning phase. Almost every company has to deal with such "events" every few years or sometimes even just months.

It is important to avoid panic in the event of damage. It would be desirable to protect our cleanrooms against such damage in the future through improved planning and design.