Daikin Confirms Effectiveness of Streamer Technology to Inactivate Coronaviruses (SARS-CoV-2) and Mouse hepatitis virus A59 (MHV-A59)
23 September 2020 / Activity
Daikin Industries, Ltd., in cooperation with Professor Shigeru Kyuwa, Department of Biomedical Science, Graduate School of Agriculture and Life Science, the University of Tokyo, and a group of research professors led by Professor Shigeru Morikawa, Department of Microbiology, Faculty of Veterinary Medicine, Okayama University of Science, have demonstrated that Daikin’s unique Streamer technology has an inactivating effect on Coronavirus (SARS-CoV-2) and Mouse hepatitis virus A59 (MHV-A59).
In seeking to verify the effectiveness of Streamer technology since 2004, Daikin has previously demonstrated over 60 types of harmful substances, such as bacteria, allergens and viruses including influenza virus (type A, H5N1) and mouse noroviruses, to be suppressed or inactivated by Streamer technology. From the latest study, Daikin has confirmed that Streamer technology inactivates more than 99.9% of coronavirus (SARS-CoV-2) and mouse hepatitis virus A59 (MHV-A59) after irradiating the viruses for three hours with Streamer discharge.
This demonstration shows the results of experiments using a device that generated Streamer discharge under test conditions and does not indicate the effectiveness of an actual Streamer product in use under actual conditions (living space).
■ Experimental Results Irradiation with Streamer discharge for one hour inactivated 93.6% of coronavirus (SAR-CoV-2) and 91.8% of mouse hepatitis virus A59 (MHV-A59).
Irradiation with Streamer discharge for three hours inactivated more than 99.9% of coronavirus (SARSCoV-2) and mouse hepatitis virus A59 (MHV-A59).
■ Evaluation Method The mouse hepatitis virus strain A59 (MHV-A59) is a virus that belongs to the Betacoronavirus genus of the Coronaviridae family, a family of enveloped, positive-sense, single-stranded RNA viruses in the Nidovirales order, and is one of the viruses belonging to same genus as coronavirus (SARS-CoV-2). Firstly, an experimental system was established using mouse hepatitis virus A59 (MHV-A59), and then an evaluation was performed using coronavirus (SAR-CoV-2).
In this experimental system, two acrylic boxes of about 31L were mounted inside a safety cabinet. One box was equipped with a Streamer discharge device and the other box was not. A see-saw rocking motion shaker was placed in each box, and a six-well plate was placed on top of the motion shaker. Virus solution measuring 0.5 ml was put into each well of the plates, and Streamer irradiation was performed while agitating the solution using the motion shaker (approximately 12 times per minute). Virus solution was collected from two wells every hour for three hours, and the viral load was measured.
The viral load for mouse hepatitis virus A59 (MHV-A59) was quantified by the plaque method using DBT cells, whereas the viral load for coronavirus (SARS-CoV-2) was quantified by the TCID50 method using Vero E6 / TMPRSS2 cells.
■ Streamer Technology Streamer technology is a technology that uses Streamer discharge, which Daikin developed in 2004, to perform oxidative decomposition of harmful substances. It is a type of plasma discharge featuring an innovative air purification technology that stably generates “high-speed electrons,” a feat which had proven difficult up to that time. Its oxidative decomposition capability is much greater than that of conventional plasma discharge (glow discharge). Moreover, when combined with air components, these high-speed electrons have a capability for powerful oxidative decomposition, and this capability enables Streamer discharge to continuously remove odors, bacterias, and indoor air pollutants such as formaldehyde.
To date, Daikin has been collaborating with universities and public research institutes to demonstrate the effectiveness of this technology for highly virulent influenza viruses (A-type H5N1), weakly virulent influenza viruses (A-type H1N1), mouse norovirus, and toxins and bacterias that cause food poisoning.
■ Types of viruses that have been demonstrated so far In addition to below viruses, the effectiveness against 7 types of bacteria such as Legionella and Pseudomonas aeruginosa, 30 types of allergens such as cedar pollen and Dermatophagoides farinae (excrement/carcass), and 19 types of harmful chemical substances have been verified by public institutions.