Oxygen Deprivation with CO2 and Anoxia Encapsulations to Achieve Cellular Desiccation

     Mold, microbial microorganisms and pests must be addressed as contaminants. A contagion that has the potential for ongoing damaging life-cycles, that can become widespread throughout collections. Handling any seemingly minor situation properly is imperative, so as not to wind up with an expensive emergency to clean up later.  Appropriate treatment protocols for effective assurance that mold and branching mycelium cellular structures have fractured and cannot reproduce is a mandate to be followed in a most exacting controlled manner.

     Carbon dioxide (CO2) is a cold, non-combustible, non-flammable, non-poisonous, liquefied gas, which is both inexpensive and easily stored at work sites—and does not require a permit or license for use in California.  CO2 gas can be safely monitored and controlled within a workspace with adequate ventilation.  Nitrogen and Argon gases can also be used in this application, however, Argon gas will take more gas to reach a concentrated 95% mixture by volume, and is quite expensive to use as the primary agent.  Nitrogen is also a viable choice, but can introduce further moisture, and is not appropriate for all art mediums and materials.

     Our encapsulation bubbles or tent chamber run for periods of 3-5 or 7-9 weeks total, depending on the infestation, contents and exterior temperatures.  This treatment removes the oxygen from the enclosed environments and replaces the ambient air with CO2 gas.  We maintain and continually flush the enclosures with gas over the duration to keep the concentration up to an average of 95% by volume.  This causes any microbial infestation and/or pest infestations to desiccate and be successfully eliminated.   The soft microbial cellular walls will severely dehydrate, burst or split open and fracture—assuring that no dormant state CFU’s remain viable to become active at a later time or place when the humidity may be higher and the environment more hospitable.  This treatment is a non-invasive, safe approach in conservation, and will not harm the objects, or artworks if all is prepared appropriately and monitored closely.


The four phases of CO2 anoxic oxygen deprivation and dehydration treatment are as follows:

• Phase One  Testing for leaks with the TIF Instruments 8800 Combustible Gas Detector.  Generic canned air was sprayed in the interior corners and seams to test the seals. The combustible gas meter can detect the propellant.
• Phase Two  Purging and flushing the enclosed environment of ambient air to reach a low oxygen 0.1 - 0.01% concentration.
• Phase Three  Continued flushing with direct drawn suction and CO2 induction filling, to contract and expand the volume of interior space, until 85% CO2 saturation mixture is achieved. Once this point has been reached it must be kept constant 24/7 for a period of 4-5 weeks.
• Phase Four  Evacuation of CO2 by vacuum pump to the outside exterior of the building and repeated flushing with fresh ambient air, until the interior CO2 monitor reading is below 500 PPM.  Then the tent encapsulation can be opened and the objects removed to Clean Stage Isolation Room 1.
• CO2 is an inert, non-flammable, non-toxic, non-combustible, cold gas.