We have been responding to an incredible number of inquiries asking about using PURETi as an anti-viral to help deter the spread of COVID-19, and this page is designed to share with you some of the scientific research about photocatalytic surfaces and viruses.
From the time of its discovery, the benefits of photocatalytic TiO2 as an antimicrobial have been the focus of significant scientific study. The basic function of the TiO2 nanoparticle is to generate hydroxyl radicals and super oxide anions from the water and oxygen in the air. These two cleaning agents in turn have been shown to be effective against a wide range of organic pollutants (VOCs, soot, mold, bacteria, and viruses), as well as inorganic pollutants (NOx and SOx).
At PURETi, our focus has been on the use of photocatalytic TiO2 as an air purifier and surface cleaner. However, in light of current events we feel it is important that people understand what options are available to them to create cleaner, healthier, safer environments. The way photocatalytic oxidation works (generating hydroxyl radicals and super oxide anions at the surface) is broadly anti-microbial as detailed below.
The following three papers can be found at the website of the National Institutes of Health’s National Center for Biotechnical Information.
Comparison of Infectious Agents Susceptibility to Photocatalytic Effects of Nanosized Titanium and Zinc Oxides: A Practical Approach “Methods using photocatalytic properties of nanosized TiO2 and ZnO prove to be highly efficient in inactivation of infectious agents…A reduction of infectious agent transmission in the public space can be achieved thanks to the photocatalytic properties of self-disinfecting and self-cleaning surfaces. Their crucial compounds are oxides of some metals, such as TiO2 and ZnO, which, after they have been powdered to NPs, exhibit strong virucidal, bactericidal, and fungicidal properties.” J. Bogdan et al, Nanoscale Res Lett. 2015; 10: 309. Published online 2015 Aug 4. doi: 10.1186/s11671-015-1023-z
Photocatalytic inactivation of Influenza virus by Titanium Dioxide Thin Film. "Titanium dioxide (TiO(2)) under ultraviolet (UV) light produces a strong oxidative effect and may therefore be used as a photocatalytic disinfectant... Even with a low intensity of UV-A (0.01 mW cm(-2)), a viral reduction of approximately 4-log(10) was observed, equivalent to a reduction of 99.9999%, in a short irradiation time". R. Nakano et al. Photochem Photobiol Sci. 2012 Aug;11(8):1293-8. doi: 10.1039/c2pp05414k. Epub 2012 May 14.
Generation of reactive oxygen species (ROS) by photocatalysis on TiO2 is capable of killing a wide range of organisms including bacteria endospores in water, in air and on surfaces, including various materials. The technology has the potential to provide a powerful weapon in the fight against transmission of infectious diseases, particularly in view of the development of visible light-activated catalysts.
Viruses shown to be killed by photocatalytic disinfection:
Host Virus Reference: Bacteroides fragilis Not specified Armon et al. (1998), Birds Influenza (avian) A/H5N2 Guillard et al. (2008), E. coli Coliphage Guimarães and Barretto (2003), E. coli fr Gerrity et al. (2008), E. coli T4 Ditta et al. (2008), Sheel et al. (2008), E. coli λ vir Yu et al. (2008), E. coli λNM1149 Belhácová et al. (1999), E. coli φX174 Gerrity et al. (2008), E. coli MS2 Sjogren and Sierka (1994), Greist et al. (2002), Cho et al. (2004, 2005), Sato and Taya (2006a, b), Vohra et al. (2006), Gerrity et al. (2008), E. coli Qβ Lee et al. (1997), Otaki et al. (2000), Human Hepatitis B virus surface antigen HBsAg Zan et al. (2007), Human Influenza A/H1N1 Lin et al. (2006), Human Influenza A/H3N2 Kozlova et al. (2010), Human Norovirus Kato et al. (2005), Human Poliovirus type 1 (ATCC VFR-192) Watts et al. (1995), Human SARS coronavirus Han et al. (2004), Human Vaccinia Kozlova et al. (2010), Lactobacillus casei PL-1 Kakita et al. (1997, 20000, Kashige et al. (2001), Salmonella typhimurium PRD1 Gerrity et al. (2008).
During the avian flu crisis, we conducted one research study with the University of Minnesota to see the effectiveness of PURETi against feline calicivirus. Recently, the CDC has stated that this virus is a proxy for the COVID-19 virus for purposes of evaluating disinfectants (though no testing has been done specifically to COVID-19).
Note: The company name changed from TioxoClean to PURETi in 2008.
PURETi is committed to our mission to cost effectively improve human health and productivity and the environment by improving air quality. We are confident that our best-in-class products play an important role in the ecosystem of solutions when endeavoring to create healthy environments.
At a time when many businesses and families are looking to do everything possible to create healthier environments, we believe that treating surfaces that get exposure to UV-A light (outdoor surfaces, interior windows, light fixtures, curtains) is a simple and valuable contributor to an overall cleaning and disinfection program. PURETi can provide an additional layer of defense of long lasting effect (2 to 5 years indoors) in this battle.
Thank you for sharing our commitment, and please contact us if you have any questions at firstname.lastname@example.org
Thank you for taking the time to learn more about how PURETi can help create healthier and more productive environments disinfecting with light.