UV light can be categorized into UV-A, UV-B, UV-C, and UV-D based on wavelength. UV light has various effects including disinfection, sterilization, and promoting bone and skin health but prolonged exposure can also cause skin damage and cancer. UV-A has strong penetration power and makes up most sunlight reaching the skin, causing tanning, aging, and wrinkling. UV-B produces vitamin D with sun exposure but too much can lead to skin cancer. UV-C is mostly absorbed by the ozone layer and causes cancer with brief exposure but is effective for sterilization used in hospitals, food processing, and more.

1. UV LED including long wavelength UV-A (315~400nm), middle wavelength UV-B (280nm
~315nm), short wavelength UV-C (200~280nm) and Vacuum wave UV-D (<200nm). The UV
light can helps Disinfection, Sterilization, Promote bone development, Treatment
certain skin disease, Promote body mineral metabolism and the formation of
vitamin D, etc. Also they may lead to the sun spots, mature skin, dermatitis,
even dermal cancer, etc.
Different UV light have different effects. Here below introduce these UV lights:
UV-A
has stronger penetrating power, it can penetrate glass, even 9 ft deep water.
Under the daylight, more than 95% infrared can be touched by our skin is UV-A,
it is also the most harmful to our skin, makes the skin darkening, loose,
wrinkle and more serious.
The wavelenth of UV-A comply with the insects' favorite lighting, it can be used
for producing Trap Lamp, counting machine or Ore identification machine...
UV-B
mostly have been absorbed by Ozonosphere, only 2% can reach to earth, in the
summer and afternoon, it has strong power, even can be helped to produce Vitamin
D. Under the blazing sun for quiet a long time, if may result to skin cancer and
black spots. Many manufacturer researched special lights like health care light,
or grow light, as per the wavelength.
UV-C
almost have been absorbed by Ozonosphere before get into the earth. Once been
touched shortly, it would cause skin cancer. But it is good at sterlizing. It
has been widely used in the field of hospital, air conditioner, food industry,
milk industry, bakery and refrigerations...