Desiccators in the Cleanroom: What are the Options? Part 3

When traditional desiccators aren’t clean enough to use in your controlled environment, what are your options?

Desiccators provide storage of small quantities of pre-dried samples or hygroscopic chemical reagent that is both economical and long-term. In a laboratory, a glass jar desiccator is perfect for its purpose. However, in a cleanroom, this storage method can compromise the integrity of the cleanroom or the sample.

In part one, we looked at glass desiccators. These are the most economic, but also the least advantageous in a controlled environment. They cannot maintain the low levels of relative humidity that are required when manufacturing semiconductors, medical devices, or pharmaceuticals. Additionally, once the desiccator reaches its saturation point, it has to be manually handled to regain its adsorptive qualities.

Dry cabinets are one alternative to glass jars. They offer a controlled RH level with greater storage capacity. Products are easily accessed, and the cabinets have low relative humidity monitoring and even set point controls. However, the cabinets also pose a risk of contamination to the environment because of the fans used during operation. So both of these options have significant drawbacks in a cleanroom.

For a cleaner alternative, dry nitrogen gas is the best desiccating medium. Without contributing particles, a nitrogen-purged system provides superior RH control with automated set points far below 5% RH. It maintains an inert environment for anything that is sensitive to humidity or other chemical vapors.

The variable-purge system uses highly precise RH sensors and effective airflow engineering to minimize humidity recovery times while conserving nitrogen. All things considered, these systems are the most cost-effective for any product that will experience high defect rates with even a little exposure to moisture in the air.

Do you need cleanroom certification or validation? Looking to build a modular cleanroom? The experienced staff at Gerbig Engineering Company has 30 years of expertise that you can depend on. Call us at 888-628-0056 or

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