Atmospheric & Pressurized Cold Plasma Technologies

US EPA: "Highly Efficient, And Cost-Effective Means To Eliminate Disease-Causing & Contaminating Microorganisms From Indoor Air Streams. ...Cannot Be Overstated."

For one searching for means to eradicate unwanted mold, bacteria, viruses or VOCs from homes or buildings, Plasma may sound complicated, yet is a relatively simple and quite safe microbial sterilization technique that is utilized in a variety of applications for its low operating costs and non-polluting capabilities. Though plasma is an electrical term, it is considered the fourth state of matter by many leading physicists, and is generally described as a gaseous form of energy.

How It Works With Air - When a modulated electric field is applied to a pair of electrodes, a plasma is formed, which makes the Oxygen molecules of the air passing near the electrodes break down into reactive oxygen species (ROS). Organic substrates such as bacteria, viruses and mold spores that become exposed to these ROS are destroyed or rendered harmless on contact, and the same reaction convert the ROS back into oxygen. In fact, any amount of air that is exposed to the ROS becomes substrates-free.

Plasma Technologies & Applications - Technical Information Sources

US EPA: Overwhelming Final Report On Atmospheric Plasma Research

DOE & US Air Force: Cold Plasma Decontamination Research At Los Alamos

University Of Tennessee: Plasma Applications Development through NIH, DoD & EPA

American Physical Society: Killing Airborne & Surface Microorganisms With Cold Plasma

South West Research Institute: $2M Plasma Technology & Applications Research

Discharge Plasma: Sterilization of Materials with a One Atmosphere Discharge Plasma

Markland Technologies: Plasma Effects On Nerve Gas & Deadly Biological Agents Like Anthrax

Research & Technology Society (France): Medical Sterilization Per Cold Plasma - A Must See

Disclaimer: In compliance with Federal Trade Commission (FTC) rules, Air Tech International does not make individual statements (claims), entertain scientific, professional or personal opinions regarding these technologies, or their current or future applications. The following material is of general public access and is hereby provided for references only.

Plasma-Generated Ozonolysis Testing Results

"There is a possibility of 53 chemical substances, which are emitted from dry-cleaning clothing. Fully 2/3 of these chemicals are controlled and regulated by OSHA in industrial settings. These chemicals may be broken into eight groups, all but one of which react with a cold plasma ROS to form harmless compounds:

• Organic acids, Alcohols, Aldehydes, and keytones: Forms carbon dioxide, water vapor and releases oxygen
• Aromatic Compounds such as benzene and camphor: Forms carbon dioxide, water vapor and releases oxygen
• Aliphatic Compounds such as butane and mineral spirits: Forms carbon dioxide, water vapor and releases oxygen
• Chlorides such as Methylene chloride:  Forms carbon dioxide, water vapor, CL2O, and releases oxygen after an intermediate Hypochlorite state
• Nitrogen Compounds such as Hydrogen Cyanide: Forms carbon dioxide, water vapor and releases nitrogen and oxygen
• Sulphur Compounds such as Ammonium Thiglycolate: Forms carbon dioxide, water vapor sulfur trioxide, and releases oxygen (and occasionally nitrogen)
• Other Alkylated Silicates and non Ionic detergents: Forms carbon dioxide, water vapor and releases oxygen
• Non reactive compounds such as calcium oxide, silica titanium oxides, etc.: No reaction.

While these chemicals are not inclusive of all the chemicals found in the home and work place, they are representative of the families of chemicals that do exist there. In addition, other tests have shown that common household bacteria, mold, mildew, and fungus are greatly reduced in typical household environments. Specifically, E-Coli, Salmonella Choleraesuis, Staphylococcus Aureua, Candida Albicans, and Aspergillus Niger have been shown to have dramatic reductions in population in independent laboratory tests."

"98th General Meeting of the American Society for Microbiology

May 17-21, 1998, Atlanta, Georgia

For more information on any presentation at the 98th General Meeting contact Jim Sliwa, Public Communications at jsliwa@asmusa.org.

Reference #: 423/974-0286 - Paper P-101, Session 257-P

While Americans enjoy a food supply that is among the safest in the world, food producers are continuously searching for new, state-of-the-art technologies that further improve food safety and quality. Food safety is a major concern of every sector of the food industry, with recent attention being focused on the meat and poultry industry. Current methods in reduction of microorganisms associated with food may pose problems with regard to residual food changes, the presence of resistant organisms, questions of cost and the necessity for elaborate facilities.

To answer the need of new methods in sterilization and pasteurization, a collaborative group of researchers at the University of Tennessee, Knoxville have developed the technology of room temperature sterilization using a one atmosphere uniform glow discharge plasma. An exploratory research program involves the Department of Electrical Engineering, Department of Microbiology, Textiles and Nonwovens Development Center, and Department of Food Science and Technology.

This proprietary University of Tennessee plasma process greatly reduces or eliminates high temperatures, toxic compounds, or harmful high-energy radiation associated with standard sterilization processes. In experiments performed thus far, atmospheric plasma is a very safe, gentle and rapid method (seconds) to reduce microbial loads on porous and non-porous surfaces. The sterilization process can be carried out at room temperature and complete killing was observed in conventional sterilization bags in less than one minute of exposure.

Process applications are currently being investigated is for use as a mechanism of pasteurizing foods and controlling foodborne pathogens such as E. coli O157:H7, Listeria monocytogenes, Campylobacter jejuni, and various Salmonella species. Experimental data indicate that thousands to millions of E. coli O157:H7 cells were killed in as little at 5 to 15 seconds of plasma when the cells were applied to the surface of the test material such as polypropylene. When the E. coli O157:H7 cells were embedded in a gel matrix, the exposure time was extended to 2 minutes or less. Such short exposure times may have little effect in the physical and organoleptic properties of food such as taste and texture but greatly reduce the bioburden present in foods.

This study was extended to include other microorganisms to demonstrate the efficacy of this method as a general sterilization procedure. Bacteria, bacterial spores, fungi and viruses on non-porous and porous surfaces that were exposed to the process. Microorganisms at levels of 10,000 to 10,000,000 were routinely killed in seconds to minutes even when the samples were placed in conventional medical sterilization bags.

This technology has the potential for development of more efficient and safer means of reducing the bioburden in foods and sterilization for industrial and medical industries. Another important area of our research currently being funded by the Air Force is a plasma process to decontaminate military equipment exposed to various biological and chemical warfare agents. This developing plasma reactor will be portable and capable of decontaminating a number of interior and exterior surfaces of planes, tanks, etc. and personal military equipment."

• Dorai, R., K. Hassouni, and M. J. Kushner. Interaction between soot particles and NOx during dielectric barrier discharge plasma remediation of simulated diesel exhaust. Journal of Applied Physics 88:6060 (2000).

• Hwang, H. H., E. R. Keiter, and M. J. Kushner. Consequences of 3-dimensional physical and electromagnetic structures on dust particle trapping in high plasma density materials processing discharges. Journal of Vacuum Science and Technology A 16:2454 (1998).

• Kinder, R. L. and M. J. Kushner. Wave propagation and power deposition in magnetically enhanced inductively coupled and helican plasma sources. Journal of Vacuum Science A19:76 (2001).

• Zhang, D. and M. J. Kushner. A surface kinetics and plasma equipment model for Si etching by fluorocarbon plasmas. Journal of Applied Physics 87:1060 (2000).

• National Air Pollutant Emissions Estimates, 1900-1991, U.S. Environmental Protection Agency Publication No. EPA-454/R-92-013, October 1992.

• M.G. Grothaus, E.R. Fanick, D. Bannon, B.B. Bykowski, M. Grimes, "Pulsed Corona Reactor for Efficient Destruction of Hazardous Gases," Southwest Research Institute Internal Research and Development Program, Project No. 10-9857."

• 4. P. Burggraaf, "Process Exhaust Treatment" Semiconductor International, April 1993, pp. 44-47.

• "Nonthermal Plasma Techniques for Pollution Control, Parts A & B"; edited by B. Penetrante and S. Schultheis, NATO ASI Series G: Ecological Sciences, Vol. 34, Parts A and B, Springer-Verlag, Heidelberg, 1993.

• G. Wakalopulos, "Electron Beam Array for Surface Treatment"; May 9, 1995.

• M.G. Grothaus, R.K. Hutcherson, R.A. Korzekwa, R. Brown, M.W. Ingram, R. Roush, S. Beck, M. George, R. Pearce, and R. Ridgeway, "Gaseous Effluent Treatment Using a Pulsed Corona Discharge" Proceedings, 10th Institute of Electrical and Electronics Engineers Conference on Pulsed Power, Albuquerque, New Mexico, July 10-13, 1995.

• E.R. Fanick and B.B. Bykowski, "Simultaneous Reduction of Diesel Particulate and NOx Using a Plasma"; presented at the Society of Automotive Engineers Fuels and Lubricants Meeting and Exposition, Baltimore, Maryland, October 17-20, 1994

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