Stanley's
UV-C Technology
〜For a cleaner and safer world〜

The new coronavirus made us aware of various hygiene risks

The new coronavirus (COVID-19) threat to humanity highlights the global lurking of hygiene risks, from our homes to the entire society.
At the same time, it shows that taking countermeasures (sterilization/disinfection) against these risks is necessary.
Everything we come in contact with (water, air, any object) requires said countermeasures to be taken effectively through various methods.

The sterilizing effect of Stanley Electric's UVC technology can protect people from harmful bacteria and viruses.

What is UVC?

Ultraviolet refers to invisible light spanning a range of wavelengths between about 100 to 400nm.
UVC (deep ultraviolet) light does not exist in nature, because its wavelength ranging from about 100 to 280nm cannot reach the Earth. Nonetheless, UVC light performs a wide range of functions such as sterilization, organic decomposition, photopolymerization and sensing.
Stanley Electric has the technology to make high-power LEDs in the UV-C range and is particularly focused on sterilization.

Main feature of UV Sterilization

There are several methods for sterilization such as heat and chemicals. UV sterilization is one of the methods which uses UV irradiated light. It has features not found in other sterilization methods and is used in many applications.

Pros	Cons
・Since no chemicals are used, no need to wipe off or remove ・Effective against chlorine-resistant micro-organisms that are not sterilized by chlorine ・Does not produce UV-resistant bacteria	・Hazardous to the human body and organisms (acute/chronic UV damage) ・Damage to plastic materials such as synthetic resin ・Cannot sterilize places where the light does not reach or places in shadow

Sunlight also contains UVC, but most of them are absorbed by the ozone layer before reaching the earth's surface. ^※
Therefore, it is necessary to produce UV-C light artificially with LEDs and lamps in order to use UVC rays on earth.
^※Sun disinfection (sun drying) does not actually contain any UV sterilization effect which is highly effective against bacteria. In this case, most of the sterilization is achieved by drying and heat.

UVC has harmful effects on the human body.
Do not look directly at the light, or shine on your skin.
Also, please be careful of UV leakage and reflection during in use.

The method for measuring (total light intensity or UV irradiation intensity) the bactericidal effect of UV sterilization is to calculate the intensity of light (illuminance) and the total time of irradiation (irradiation time).

The longer the light is irradiated, the more the total light intensity,
and therefore the bactericidal effect increases.
On the other hand, if the irradiation time is short, a more powerful level of UV light will be needed to achieve sufficient sterilization.

How to calculate the total light intensity

e.g.: 40mJ/cm² of UV irradiation intensity is needed to sterilize 99.99% of Bacteria A

Principle of UV sterilization

Bacteria and viruses multiply by replicating the genetic material found in the nucleus of living cells, thus leading to infections and onset.
DNA and RNA possess the genetic material necessary for proliferation.
The UVC range of light can change and rearrange the "strands" constituting the helical structure of DNA/RNA.

UV sterilization becomes possible by "inactivating" DNA/RNA

Effectiveness of UV sterilization

UV sterilization can achieve a reliable bactericidal effect simply by irradiating UV rays. It can also sterilize pathogenic micro-organisms that cause infectious diseases and health problems in the human body.
This is effective against various bacteria and viruses including new coronavirus. Many universities, research institutes, and companies are studying UV sterilization.

Typical micro-organisms subject to UV sterilization

The size of micro-organisms	Type of micro-organisms	Typical example
	Virus	Coronavirus, Influenza virus, Norovirus
	Bacteria	Escherichia coli, Legionella, Salmonella
	Fungus	Black mold, White mold, Trichophyton
	Protozoa	Cryptosporidium, Giardia

99.9% sterilization time

Difference in bactericidal effect according to wavelength

This graph shows the correlation between the UV sensitivity of the DNA of living organisms' , and the wavelength of deep UV light irradiated from LEDs or lamps.
The higher the UV sensitivity, the greater the damage received from UV. DNA has a peak sensitivity to UV light at around 265 nm.
Our LED has a peak wavelength of 265 nm which has the maximized sterilization effect. We have developed and produced LEDs which can achieve excellent sterilization performance.

The sterilization effect changes depending on not only the brightness but the wavelength.
It is important to select UVC rays with an effective wavelength.

Evaluation of effectiveness against new coronavirus

We have confirmed the effectiveness on the new coronavirus (SARS-CoV-2).
The evaluation tests conducted with Yamaguchi University (Dr. Daisuke Hayasaka and Dr. Hiroshi Shimoda, Laboratory of Veterinary Microbiology, Joint Faculty of Veterinary Medicine) confirmed the high effectiveness of UV sterilization.
In addition,we have confirmed the superiority of the wavelength emitted by our mass-production UVC light sources.

The new coronavirus inactivation evaluation test

Relative comparison of sterilization performance by wavelength (280nm = 1)

Stanley Electric's approach to UVC LEDs

Hexatech; the manufacturer of AlN substrates which are key devices for 265 nm UVC LED die material,
became a new member of the Stanley Group in March 2020.
This means the LED manufacturing process, which consists of AlN substrates, LED elements and packaging,
can be completed within the Group.
We also provide sterilization unit products such as water sterilization reactors.
We are contributing to the safety and security of the world comprehensively through the development and manufacture of components through to full solutions.