Many of the air purifiers offered here on PureAirProducts.com can be equipped
with optional UV filters based on Ultraviolet Germicidal Irradiation technology.
This technology uses ultraviolet (UV) light at a very short wavelength to break
down micro-organisms. The short wavelength of this UV light is virtually
harmless to humans and pets and normally blocked by our atmosphere, but is
extremely harmful to micro-organic life forms such as airborne pathogens,
bacteria, viruses and mold. The light destroys nucleic acids within these
organisms, damaging their DNA through UV radiation. This either permanently
disrupts the ability to reproduce, or kills the organisms.
When used with a filtration system, UVGI can remove harmful micro-organisms from
indoor environments. At specific wavelengths short range ultraviolet light (UVC)
is mutagenic to bacteria, viruses and other pathogens, breaking down the
molecular bonds that hold their DNA together either destroying them entirely,
rendering them harmless or preventing growth and reproduction. The effect can be
compared to the familiar effect that longer wavelength ultraviolet light (UVB)
has on humans: Sunburn. Unlike humans micro-organisms have much less protection
from UV light and cannot survive prolonged exposure to it without sustaining
Germicidal UV is delivered by a mercury-vapor lamp that emits UV light at the
required wavelength. Many bulbs use transformers to ensure even electrical flow
to maintain a steady wavelength, Since the bandwidth of the UV light is so
narrow any fluctuation in power can reduce its effectiveness. When used in
closed environments such as duct systems germicidal UV is lethal to all
micro-organisms over time. Generally speaking, the longer a micro-organism is
exposed to UV the better the effect. With the aid of fans, many air purifiers circulate air
repeatedly with the aid of fans to expose organisms to the UV light as often as
possible. This is done to ensure the light is effective against even the more resistant
micro-organisms, irradiating them more than once to break down their DNA.
Some side effects exist with UVGI technology. Since UV light is harmful to
humans and animals at certain wavelengths most of today's units shield the UV
bulbs and limit their exposure. Many units feature shut-off mechanisms which
automatically turn off any UV light components should the unit be opened.
Prolonged exposure of the skin to germicidal UV light can produce sunburns and,
in severe cases, skin cancer. Serious damage to the eyes can occur if exposed,
such as cornea inflammations, retinal damage, temporary or even permanent vision
impairment up to and including blindness.
Germicidal UV light produces a small amount of ozone as a by-product. Ozone
occurs naturally in the Earth's stratosphere where it shields the planet from
radiation, but at an atmospheric level ozone can be harmful to human health,
with many people showing more pronounced sensitivity to ozone than others. The
United States Environmental Protection Agency (EPA) considers .05 parts per
million (ppm) of ozone in indoor air to be safe. Germicidal UV radiation is also
capable of breaking down chemical bonds, such as in plastics, over time weakening
materials. Taking into consideration that most electronic devices produce safe
levels of ozone as a by-product, and PureAirProduct.com's dedication in bringing
you products that improve indoor air quality all UVGI air purifiers offered on
this site are safe to use in the home.
The UVGI technology has been used in the medical field for over a century.
In 1903 Danish researcher Niels Finsen was awarded the Nobel Prize in Medicine for his
pioneering use of UVGI against lupus, tuberculosis and other diseases.
UVGI technology has been used in many other sterile work facilities, most prominently in water treatment plants to sterilize drinking and wastewater.
Besides hospitals and laboratories using UVGI you will find barbershops, piercing studios, and tattoo parlors using forms of UVGI technology inside sterilization tanks to sterilize equipment that comes in contact with the human body. The food
and beverage industry also makes use of UVGI technology to sterilize produce and
in particular fresh fruit juices. In aquariums and ponds UVGI is used to inhibit
the build-up of single-cell algae. UVGI technology has been proven to
successfully clean indoor air, especially when used in conjunction with other
air filtration systems such as HEPA or activated carbon purifiers. Choosing
an air purifier with an optional UV filter will provide increased air cleaning
capabilities and give you the added health benefits of cleaner air in your home.
A selection of our products using UVGI technology: