Recent advancements in medical equipment and the increasing threat of microbial contamination have heightened the need for cold and dry sterilization processes in healthcare facilities. This article introduces the working mechanisms of plasma sterilizer systems, their technical specifications, physical structure, operational principles, and compares the advantages of this method over traditional sterilization techniques.
Introduction:
The introduction of plasma sterilizers in healthcare centers (known worldwide as hydrogen peroxide vapor sterilizers) has revolutionized sterilization practices. Research into this method began in the 1960s, and numerous studies have been conducted to determine the optimal parameters such as pressure levels and hydrogen peroxide concentration, which significantly affect the quality of sterilization. Key questions raised in this context include:
Why should plasma sterilizers be used as an alternative to traditional methods? How do these devices function? What is the technical and physical structure of the device? What are the basic operating principles? This article provides answers to these questions.
Summary of Results:
Reasons to Use Plasma Sterilizers:
In sterilization departments, traditional steam autoclaves are insufficient for sterilizing all hospital equipment. These autoclaves operate at high temperatures (121-134°C) and high humidity, which can damage sensitive equipment such as electronics, endoscopes, laparoscopes, and plastic or silicone instruments. Cold and dry sterilizers operate at a lower temperature (50-55°C) in completely dry conditions, making them ideal for these sensitive items. Plasma sterilizers, with advantages like high speed, safety, low operational temperatures, dry conditions, no unpleasant odors, and no post-sterilization waiting time, have become a preferred alternative to older methods like ethylene oxide and formaldehyde.
How the Device Works:
While plasma sterilizers use a variety of mechanisms that each have potential disinfecting capabilities, the primary method employed by all manufacturers is the use of hydrogen peroxide vapor as the main sterilizing agent. Hydrogen peroxide’s strong oxidizing properties destroy microorganisms by breaking down their DNA. The chemical structure of hydrogen peroxide, which contains an extra oxygen atom compared to water, allows it to function as a potent oxidizer.
Plasma, considered the fourth state of matter (solid, liquid, gas, and plasma), is created when gas is highly ionized, with the number of free electrons nearly equal to the number of positive ions. Applying energy to a gas can convert it into plasma. Contrary to some misconceptions, the sterilization process in these systems is primarily carried out by hydrogen peroxide vapor, not plasma itself. The role of plasma in the system is to eliminate the residual hydrogen peroxide vapor remaining after the sterilization process. While free radicals in plasma can have some disinfecting effects, their role is secondary to that of hydrogen peroxide vapor. Additionally, ultraviolet rays emitted from the plasma phase contribute to disinfection, though their significance is secondary to the hydrogen peroxide vapor in the overall process.
General Working Cycle of the Device:
Since moisture negatively affects the quality of sterilization, all instruments must be completely dry when placed in the system. Some systems use heating elements on the body and chamber lid, as well as internal fans and heaters, to eliminate any residual moisture on the instruments.