This document is an English translation for understanding the contents of Daikin press release that introduces theresults of experiments using the Streamer discharge device. The effect of products equipped with Streamer
technology or the effect in actual use environment may differ. This English translation cannot be used in association
with products, including sales promotion (such as proposal materials for product sales).

July 16, 2020

Daikin Confirms Effectiveness of Streamer Technology to Inactivate
Coronaviruses (SARS-CoV-2) and Mouse hepatitis virus A59 (MHV-A59)
Inactivation of the Novel Coronavirus (SARS-CoV-2) Exceeds 99.9% after 3 Hours
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 effecton 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) andmouse 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 (SARS-CoV-2) and
91.8% of mouse hepatitis virus A59 (MHV-A59) when compared to without Streamer.
Irradiation with Streamer discharge for three hours inactivated more than 99.9% of coronavirus (SARSCoV-2) and mouse hepatitis virus A59 (MHV-A59) when compared to without Streamer.

Source1: “Study report on the inactivation effect of plasma ion generator (Daikin Streamer) on SARS-CoV-2” written byShigeru Morikawa, Department of Veterinary Medicine, Microbiology Course, Okayama University of Science.
Source2: "Study on inactivation of plasma ion generator (Daikin streamer) against mouse coronavirus" written by Shigeru
Kyuwa, Laboratory of Animal Science, Graduate School of Agricultural and Life Sciences, University of Tokyo1

This document is an English translation for understanding the contents of Daikin press release that introduces
the results of experiments using the Streamer discharge device. The effect of products equipped with Streamer
technology or the effect in actual use environment may differ. This English translation cannot be used inassociation with products, including sales promotion (such as proposal materials for product sales).

■ Evaluation Method
The mouse hepatitis virus strain A59 (MHV-A59) is a virus that belongs to the Betacoronavirus genus of theCoronaviridae family, a family of enveloped, positive-sense, single-stranded RNA viruses in the Nidovirales
order, and is one of the viruses belonging to the same genus as the 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 (SARS-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 whileagitating the solution using the motion shaker (approximately 12 times per minute). Virus solution wascollected from two wells every hour for three hours, and viral load was measured.
The viral load for mouse hepatitis virus A59 (MHV-A59) was quantified by the plaque method using DBTcells, 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 decompositionof harmful substances. It is a type of plasma discharge featuring an
innovative air purification technology that stably generates “high-speedelectrons,” 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 aircomponents, these high-speed electrons have a capability for powerfuloxidative decomposition, and this capability enables Streamer
discharge to continuously remove odors, bacteria, and indoor air
pollutants such as formaldehyde.

Streamer Discharge

To date, Daikin has been collaborating with universities and public research institutes to demonstrate theeffectiveness of this technology for highly virulent influenza viruses (A-type H5N1), weakly virulent influenza
viruses (A-type H1N1), mouse norovirus, and toxins and bacteria that cause food poisoning.
■ Types of viruses that have been demonstrated so far
In addition to the below viruses, the effectiveness against 7 types of bacteria such as Legionella andPseudomonas 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 publicinstitutions.
Demonstrated Viruses
Avian influenza virus (Type A- H5N1)

InstituteVietnam National Institute of Hygiene andEpidemiology

Influenza virus (Type A- H1N1)
Influenza virus (Type A-H3N2)
RS virus
Adenovirus, Coxsackie virus, Enterovirus,Echovirus, Measles virus

Shanghai City Disease Control Center etc.

Report Date
16-Apr-2009
14-Sep-2009
8-Feb-2010

Wakayama Medical University

13-Apr-2012

Kitasato Environmental Science Center

23-Jun-2017

University of Tokyo

11-Oct-2018

Mouse norovirus

2