The Myth of Corrosion

Chlorine dioxide (CD) is an oxidizer, as is hydrogen peroxide, ozone, bleach, and many other decontaminating agents. However, CD gas is the gentlest on materials among those options, due to its lower oxidation potential. A higher oxidation potential means it is a stronger oxidizer and more corrosive. As shown in Table 1, chlorine dioxide has an oxidation potential of 0.95V, which is lower than other commonly used oxidizing biocides. CD is not as aggressive an oxidizer (oxidation potential data) as chlorine, ozone, peracetic acid, peroxide, or bleach — and it should be non-corrosive to common materials of construction.

Table 1: Oxidation Potential of Common Biocides

While scientifically less corrosive, chlorine dioxide gas has a bad reputation due to the link with chlorine as well as the other chlorine dioxide products that lack the purity that our process uses. Other methods of generating chlorine dioxide mix an acid and a base which forms a chlorine dioxide solution which is then off-gassed to fumigate a space.  That generation method produces two acidic components, acidified sodium chlorite and chlorous acid, alongside chlorine dioxide which makes these methods more corrosive. Our method of generating pure chlorine dioxide gas is accomplished by passing a low concentration chlorine gas through a proprietary sodium chlorite cartridge to convert the chlorine gas into pure chlorine dioxide gas. This allows our process to be safe when decontaminating stainless steel, galvanized metals, anodized aluminum, epoxy surfaces, electronics, and the most common materials of construction. Typically, if water will not corrode an item, neither will our CD.

To learn more about material compatibility, click here. If you have a specific item of concern, send us some samples. We offer free material testing* to give confidence that chlorine dioxide gas will be safe on your equipment, products, components, tools, etc.

*Testing is free for small items or batches. For large items or extended testing, please call (908) 236-4100. Shipping not included.

Decontamination Chambers

A Decontamination Chamber is designed for use in any laboratory, pharmaceutical, manufacturing, research or surgical setting. It provides a rapid and highly effective method to sterilize computers, electronics, medical devices, instruments, and components at ambient temperatures. It also provides a cost-effective method to decontaminate parts, supplies, and equipment entering a “sterile” or “clean” facility without the need for a large, expensive, energy consuming sterilizer. It allows the removal of items from a dirty or BSL level area to a clean area without the concern for cross contamination.

Chlorine dioxide gas is a highly effective EPA-registered sterilant. It is a true gas which naturally fills the space it is contained within, no matter the shape or amount of items within. CD gas has more consistent kill and quicker cycles than Vapor Phase Hydrogen Peroxide (VPHP). Decontamination time can be under 1.5 hours for a 150 ft3 chamber. The chlorine dioxide process is easy to validate due to the repeatable cycle, tight process control, and highly accurate sterilant monitoring system.  A run record is produced that contains process parameters.

For many applications, a Decontamination Chamber can effectively replace a bulk autoclave inside a facility. Decontamination Chambers can save energy and money compared to bulk autoclaves in terms of steam usage, water usage, electricity usage, maintenance costs, replacement costs, cost of capital equipment, and footprint. Chlorine dioxide gas is capable of decontaminating electronics, racks, cages, HEPA filters, plastics, and the outsides of bedding and feed bags.  Autoclaves are still the best suited to decontaminate dense organic materials such as bedding and feed. As many facilities have multiple autoclaves, the easiest decision might be to implement both an autoclave and a decon chamber to fulfill all of your facility’s needs. The equipment is available in a variety of sizes including a dual door option. We also fully integrate with BetterBuilt, Lynx, Tecniplast, Girton, Schyler, Buxton Scientific, and other manufacturers.

To learn more, visit our product page or request a decontamination chamber quote.

Inactivation of Beta-Lactams

Beta-lactam antibiotics are, by definition, a class of antibiotics which contain a beta-lactam ring in their structure. They are split into various groups depending upon their base structure, with the main groups being penicillins, carbapenems, cephalosporins, and monobactams. Allergic reactions to beta-lactams can be life-threatening. Due to the large number of individuals allergic, the pharmaceutical industry explored a method for their inactivation.   This research was performed such that a contaminated area could be treated and re-used for the future production of non-beta-lactam compounds. This would allow companies to “recycle” beta-lactam facilities instead of demolishing them upon the completion of production.

Testing was conducted using chlorine dioxide gas at various concentrations and exposure times in an effort to achieve the pharmaceutical manufacturer’s required 3-log (99.9%) reduction of eight different beta-lactams on various surfaces. Nine inactivation cycles were tested, with five passing the acceptance criteria beneath U.S. Food and Drug Administration (FDA)-required 0.03 ppm residue detection level. Successful inactivation cycles which achieved a 3-log reduction of all eight beta-lactam compounds all had cumulative exposures of over 7,240 ppm-hours. Further studies validated this dosage for providing a 3-log reduction of all eight beta-lactams tested.

In 2008, a leading pharmaceutical company was looking to renovate a 33-room facility, that had been used for the production of an Imipenem-based product, into a new training facility. Because positive samples for beta-lactams were found in multiple rooms and inside the ductwork, the entire production facility along with its HVAC was to be treated. Chlorine dioxide gas was injected into 24 locations and sampled from 12 locations to ensure fast and thorough distribution.  To ensure that gas was getting into the HVAC system, the recirculation blower was bumped throughout the process. Upon completion, the area was swabbed by the pharmaceutical company. All swabs came back negative proving that no beta-lactams remained, making the treatment a success.  Since that initial facility treatment in 2008, chlorine dioxide gas has been used for this specific application at a number of other facilities worldwide.

To learn more, click here.

How Does Chlorine Dioxide React with Water?

In most cases, before a decontamination occurs, the environment undergoes a wet cleaning to remove dirt and organic material.  This residual water can present a challenge for some decontamination methods.  One example being Vapor Phase Hydrogen Peroxide (VPHP) because it dilutes and breaks down in water.  So for that method to be effective, the area must be completely dry before use.  Depending on the application, drying the environment can be a lengthy process which adds a prohibitive amount of time to the cycle.

Chlorine dioxide (CD) gas is water soluble, allowing it to maintain its sterilization efficacy within water.  Unlike chlorine, CD gas does not form hydrochloric acid and maintains a neutral pH. In wet environments, chlorine dioxide can decontaminate any remaining water as well as the surfaces beneath.  This eliminates the need to wait until the environment is completely dry before decontamination occurs, in turn, decreasing the overall downtime.

One application where this has a real world effect is within decontamination chambers.  The use of decontamination chambers is becoming more prevalent within research facilities and clean rooms.  Within vivaria where space is extremely valuable, these chambers are sometimes included as part of a dual-use rack washer/decontamination chamber unit.  Within this application, if the system is run as a rack washer, the amount of water at the bottom of the chamber afterwards can take hours to completely dry out.  Being CD gas is not affected by water, it can be used within a dual-use chamber immediately after a wash cycle.  This can save your facility hours of time and allow the savings in facility footprint to become a viable option.  It also allows a contaminated facility the ability to become completely decontaminated as there’s no worry for residual water rendering the process ineffective.

Amplicon Inactivation

The rapid growth of DNA sequencing in laboratories is resulting in the increased use of PCR readers.  As a result,  researchers are making advances in science and medicine, but not without new challenges. One challenge is that the integrity of the results can be affected if amplicon residues contaminate part of the PCR reader. This contamination could cause improper analysis of subsequent samples. Mitigation of this problem requires amplicons to be inactivated from all surfaces of the PCR reader, including all cracks and crevices of the equipment.

Chlorine dioxide gas cycles have been validated with multiple PCR reader manufacturers in order to clear the reader from residual amplicons which can cause inaccurate results and readings.  The validation consisted of a series of cycles with varying chlorine dioxide gas dosages that were tested to achieve an inactivation of the amplicons. The verification process also confirmed that the equipment was not corroded as a result of the treatment cycles.

ClorDiSys Solutions, Inc performs amplicon inactivation work as part of its contract sterilization and decontamination services.  Two manufacturers of PCR readers have their customers send equipment to our facility before having it returned to the manufacturer for maintenance and repair.  At our facility, our contract sterilization team treats the units to eliminate any residual amplicons and blood-borne pathogens. This treatment allows the equipment to be safely handled by the manufacturers' maintenance department.

For more information, please read our Application Note on Amplicon Inactivation here.