The airline industry is continually in search of the best and most efficient air filtration technology that protects air travelers from contagious airborne pathogens. This led to an almost industry-wide adoption of HEPA filtration within most aircraft today. However, even the best HEPA technology can only capture but cannot deactivate airborne viruses or bacteria. Without deactivation, the risk of infection remains.
In response, an innovative air cleaner has been developed that effectively mitigates airborne pathogens, making it a viable solution for airplanes of all sizes. The novel technology, coming out of North Carolina State University is called FIL-TEX. It is a lightweight, 2mm thin, knit filter that generates a two-dimensional non-thermal plasma (NTP) as an effective way of both capturing and deactivating contagious viruses and bacteria without emitting any byproducts.
CREM Co Labs – an independent laboratory specializing in testing for the infection prevention and control (IPAC) industry – recently published its assessment of FIL-TEX. The report authored by Dr. Bahram Zargar – an expert in virology and microbiology – demonstrated that the filter can effectively remove 99.92% of airborne viruses, and 99.99% of airborne bacteria, while deactivating 98% of viruses found on the filter’s surface. The testing was done utilizing a large, 26 cubic meter aerobiology chamber.
Improving air quality within airplanes
An article published in the American Society of Microbiology (ASM) Journal stated, “Air transportation is a major vehicle for the rapid spread and dissemination of communicable diseases, and there have been a number of reported outbreaks of serious airborne diseases aboard commercial flights including tuberculosis, severe acute respiratory syndrome, influenza, smallpox, and measles, to name a few.”
Even with the recent increased use of HEPA filters within aircraft, experts say that they simply do not go far enough in improving cabin air quality.
“Because HEPA filters merely capture pathogens and focus them in one place, the chance that any collected pathogens could be still spread remains. For example, when changing the filter,” explains Dr. Frank Scholle, Associate Professor of Biological Sciences at NC State.
These factors are prompting the industry to seek out improved solutions. Most recently, needlepoint bipolar ionization received attention for its lack of efficacy in a study conducted by Boeing. Those tests concluded that “air ionization has not shown significant disinfection effectiveness.” Furthermore, according to the Centers for Disease Control (CDC), “bipolar ionization has the potential to generate ozone and other potentially harmful byproducts indoors.”
On the other hand, FIL-TEX operates like a magnet that attracts, deactivates, and removes unwanted contaminants from the air without emitting any harmful byproducts.
Sifting out the science
Plasma – often called the fourth state of matter, alongside solid, liquid, and gas – is often found in very hot environments like lightning and stars. Non-thermal plasma, on the other hand, generates no heat but produces reactions on a microscopic scale. For example, when airborne pathogens pass through the FIL-TEX filter, they react with a 2D cold plasma field that essentially “zaps” the microorganism, deactivating the virus or destroying the bacterium’s cell wall.
“Filtration of airborne particulates can be divided into two camps – active and passive,” explains says Dr. Scholle. “This device takes the best performance characteristics from passive technologies, like HEPA, that capture particulates and active technologies, like UVC, that purify air and combine them into a single, thin, lightweight air cleaning solution.”
FIL-TEX incorporates non-thermal plasma technology with a textile filter that can be made using any yarn: cotton, polyester, polypropylene, Kevlar, and even yarn made from 100% recycled plastic. Designed so that air can pass through the system at high rates without a significant power requirement, FIL-TEX is an effective, energy-efficient solution for use in airplanes and other enclosed transportation spaces.
Proven Air Cleaning Results
While the technology was initially developed to remove smoke and particulates from enclosed spaces such as airplanes, NC State virologists decided to test the effectiveness of FIL-TEX against respiratory pathogens during the COVID crisis and found it to be a highly effective means of collecting and deactivating airborne pathogens.
In the study, an aerosolized common cold coronavirus, similar to the COVID-19 virus was introduced into an enclosed laboratory-scale tunnel with FIL-TEX situated between the inlet and outlet. A sampling of the air before and after passing through FIL-TEX demonstrated the encouraging post-filtration effectiveness of the technology.
“We had nearly a 3-log reduction in infectious virus after the FIL-TEX filter, which equates to a 98% to 99% effectiveness rating,” explains Dr. Scholle.
The aforementioned Crem Co Labs test, within their large aerobiology chamber, showed even better results, experiencing a full 3-log reduction in infectious virus. Additionally, in a separate test, the lab recorded a 4-log drop in airborne bacteria.
The FIL-TEX technology is now available from Stitch Partners to be used as a component within a device or system.