OXY-COOL Low Temp Plasma Sterilizer

Low Temperature Hydrogen Peroxide Plasma Sterilization


Not all medical and scientific equipment can be successfully sterilized in an autoclave, also known as a steam sterilizer. Let’s review why: the more complicated and technologically advanced the equipment, the more likely it will be damaged by the high temperature and humidity of steam sterilization. Our classic case is the endoscope. An endoscope will be damaged and eventually ruined by standard autoclaving. Therefore, we must find a low temperature sterilization method that is more delicate on the life of the equipment but still effective enough to fully sterilize all germs on said equipment.

Enter hydrogen peroxide, also known as H2O2. At low concentration levels, hydrogen peroxide is a common disinfecting agent sold in pharmacies. At higher concentration levels, it is used as a sterilant in many industries. And it is our sterilant of choice for this method of sterilization. How does it work?

Plasma, the Fourth State of Matter

Before we explain how hydrogen peroxide works in a low temperature sterilizer, we first need to explain the concept of plasma. Plasma is the fourth state of matter (solid, liquid, gas, and plasma) and is created when a gas is heated sufficiently or exposed to a strong electromagnetic field. What happens when a gas becomes a plasma? It becomes an unstable state of matter in which the number of electrons are increased or decreased, thus producing ions, which are positively or negatively charged electrons. In other words, plasma is an ionized gas that has special properties not seen in any other state of matter. Common examples of manmade plasmas include neon signs, fluorescent light bulbs, plasma displays used for televisions and computers, plasma lamps (as in the image above), and nuclear fusion. Naturally occurring plasmas include fire, lightning, the sun, stars, auroras, tails of comets, the Northern Lights, and even 99% of the galaxy!

How does plasma kill germs? Plasma sterilizes by a process called oxidation. The plasma produces a chemical reaction in which all microorganisms are deactivated. The high heat turns the molecules of the hydrogen peroxide into free radicals, which are highly unstable. In their “search” for returning to a stable state, they latch on to the microorganisms in the load -- thus effectively destroying the components of their cells, such as enzymes, nucleic acids, and DNA.

Hydrogen Peroxide Plasma in the Sterilizer

Liquid hydrogen peroxide is inserted into the sterilizer. The liquid is heated up in a vaporizer in order to turn it into gas. Once that has been accomplished, the hydrogen peroxide gas is heated to an even higher temperature, at which point it turns into plasma. And as we just explained, the plasma is dispersed inside the sterilizer chamber in order to oxidize all microorganisms on the load. Goodbye germs!