Sterilization Processes

Physicochemical Processes

Plasmas. Plasma is the fourth state of matter, and as such is distinguished from solids, liquids, and gases. Plasmas are produced at very high temperatures, or at low temperatures in strong electromagnetic fields (the so-called "glow-discharge" plasmas). The plasma usually consists of a reactive cloud of ions, electrons, free radicals, and other neutral species.

The plasma process seeks to produce a sterilizing effect using lower concentrations of sterilant - with a higher reactivity - than would be possible in a normal gas process. Because the active species are only present when power is applied to the system and disappear quickly when the power is turned off, the very active species that act as the sterilant will not be present as a source of toxicity at the end of the process.

The precursor gas selected for plasma generation will determine which active species are present, and these may be expected to influence the comparative microbicidal activity of the system.

When a plasma contacts the surface of an item to be sterilized, the collisions between the active species and other molecules cause a significant proportion of the active species to return to the ground state. Packaging material can thus cause a serious depletion in the concentration of active species reaching the item to be sterilized, soiling on the surface may have a significant inhibitory effect, and the extent of diffusion into narrow lumens may be limited.

Steam. The inclusion of steam sterilization in the context of recent developments in sterilization technology may at first seem strange. However, there is a continuing evolution of the equipment, packaging, and monitoring systems used for the process.

One continues to see progressive refinement of the microprocessor-based control systems and, in particular, of secondary or supporting functions, such as providing users with a prompt when maintenance is required. Control systems are becoming much more user-friendly, with touch screen systems becoming commonplace. Improvements continue to be made in related steam sterilization supplies such as packaging materials and biological and chemical indicators.  

Disclaimer

The content of this issue is presented for general information only as perceived by the writer of the article. Reader should independently verify the correctness and accuracy of the material before using the same for any purpose whatsoever. The Company or Management or Staff of Puneet Industries or the Writer shall not be responsible for any inaccuracy or error in the article.

 Back to KnowledgeBase