Hydrogen peroxide concentration systems

FDA approved for sterilization of medical equipment and clinical rooms, hydrogen peroxide offers a completely safe process that does not generate toxic residues and is environmentally friendly. 

Sterilization by vaporized Hydrogen Peroxide uses low temperature. Some of its general benefits, unlike ethylene oxide, are that there is no risk of the peroxide leaking out of the sterilization chamber into the work environment, that the user manual only recommends wearing protective gloves for handling the items to be sterilized or already sterilized and that there is no epidemiological evidence to suggest that it is a potential carcinogen.

Hydrogen peroxide has proven broad-spectrum efficacy against infections caused by viruses, bacteria, yeasts and bacterial spores, is compatible with a wide range of materials (including metal, plastic and optical instruments) and ensures biodecontamination of environmental surfaces without leaving toxic residues.

While ethylene oxide requires sterilization cycles that include ventilation, hydrogen peroxide does not need subsequent aeration, so sterile material will be available for the next procedure faster and free from toxic residues. 

According to Viviana Ghisani, Pharmacist Specialist in Sterilization at UBA (University of Buenos Aires) and Head of Sterilization Service at Posadas Hospital, “ethylene oxide requires facilities that comply with several conditions and leaves residues, while peroxide does not, which is extremely important since it speeds up times”.

Another advantage Ghisani highlights is that with hydrogen peroxide the equipment is sterilized in an average time of one hour, while a process with ethylene oxide takes 48 hours to complete. “Hydrogen peroxide’s technology is based on the high turnover of supplies, I can have an AMBU in one hour”, she says. 

During the second wave of COVID-19 in Argentina, the number of cycles performed with the MAX 2 and V-PRO 60 equipment at Posadas Hospital kept growing from 228 monthly sterilization cycles in January 2021 to 258 cycles in February and 331 in March.  

The specialist also states that whether there is COVID or not is “circumstantial”, since the equipment is used for any high turnover material and adds that “hydrogen peroxide is essential” and “I imagine neither the operation room nor myself could work without it because the speed of the cycle, which makes the material available in one hour at most, allows us to solve emergencies”.

Ethylene Oxide vs Hydrogen Peroxide

Ethylene oxide was originally used as pesticide and fumigant. This gas was patented by Gross and Dixon in 1937, noting its bactericidal properties that base its sterilizing capabilities on its toxicity towards microorganisms. At regular temperature and pressure, it has a higher density than air and is soluble in water but, on the other hand, it carries a significant potential risk and may be carcinogenic. 

Even though all microorganisms are susceptible to ethylene oxide, it is necessary to optimize the conditions of concentration, temperature, relative humidity and exposure time in order to achieve a proper sterilization, being highly risky and unproductive, for instance, to increase its concentration to reduce the sterilization process time.

As a result of several research works, its use has been questioned over the past few years, as it could lead to possible mutagenic, teratogenic and carcinogenic effects. 

Given its wide use in hospital settings as a sterilizing agent for medical-surgical instruments, it is important to bear in mind that the main routes of entry for ethylene oxide into the organism are skin contact and inhalation, so post-sterilization ventilation is crucial and its time will depend on the type of material (metal, glass, plastic, etc.) and its intended use.

In addition, it is essential that equipment has a vacuum pump for chamber air extraction and must be installed in a restricted area away from the circulation of people. The air extracted from the room shall not be recycled and shall not be connected under any circumstances to the general ventilation system.