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Categories of UV Light, What is UV Light Used For? UV Wavelengths and Colors,
Is UV Light Dangerous?
UV Light in the Electromagnetic Spectrum
UV light occupies the wavelength range between 100 and 400 nanometers (nm), sitting between visible light and X-rays. This means its energy is higher than visible light, allowing it to trigger chemical reactions and biological effects that visible light cannot.
Wavelengths and Human Visibility
Humans can see light in the 400–700 nm range. Since UV wavelengths are shorter than 400 nm, they remain invisible to us, although some animals like bees and birds can detect them.
Natural and Artificial Sources of UV
The sun is the primary natural source of UV light, contributing to vitamin D production in our skin — but also to sunburns. Artificial sources include UV lamps, tanning beds, black lights, and UV-C disinfection systems.
Categories of UV Light
Ultraviolet light is divided into 3 main categories, each defined by its wavelength and biological effect:
UVA (320–400 nm)
UVA makes up about 95% of the UV radiation reaching Earth’s surface. It penetrates deeply into the skin and contributes to aging and wrinkling. It’s commonly used in tanning beds.
UVB (280–320 nm)
UVB is more energetic than UVA and is responsible for sunburns. It affects the skin’s outer layers and plays a role in vitamin D synthesis. Overexposure can lead to skin cancer.
UVC (100–280 nm)
UVC is the most energetic and dangerous form of UV, but it is completely absorbed by the Earth’s atmosphere. Artificial UVC is used in sterilization and disinfection processes, effectively killing bacteria and viruses by damaging their DNA.
What is UV Light Used For?
UV light has a wide range of applications in both domestic and industrial contexts:
- Sterilization and Disinfection: UVC light is widely used to disinfect water, air, and surfaces by inactivating harmful microorganisms.
- Medical Equipment and Water Treatment: Hospitals use UV systems to maintain sterile environments and purify drinking water.
- Tanning and Skin Treatments: UVA and UVB are used in controlled doses for cosmetic tanning and phototherapy for skin conditions like psoriasis.
- Industrial Applications: UV curing in printing, bonding, and coating processes relies on UV light to harden resins and adhesives rapidly.
Read more about how UVC light actually work in our informative article.
UV Wavelengths and Colors
Though UV light cannot be seen by the human eye, it has distinct wavelength ranges:
- UVA: 320–400 nm
- UVB: 280–320 nm
- UVC: 100–280 nm
What Color is UV Light?
Technically, UV light is colorless to humans, as it’s beyond our visual spectrum. In scientific illustrations, it’s often represented as violet or blue for clarity.
Germicidal Effects at Specific Wavelengths
The most effective germicidal wavelength is around 264 nm, within the UVC range. At this wavelength, UV light disrupts the DNA and RNA of pathogens, rendering them inactive.
Is UV Light Dangerous?
While UV light has many benefits, it also carries risks:
Benefits and Risks of UV Exposure
- Benefits: Vitamin D production, sterilization, phototherapy
- Risks: Skin damage, sunburns, eye damage (e.g., photokeratitis), and increased cancer risk
Protection Against Harmful Rays
- Wear sunscreen, UV-blocking sunglasses, and protective clothing
- Limit exposure during midday when the UV index is high- Most opaque materials of steel, glass and polycarbonats will block UVC rays completely
Ready to harness the power of UV light for disinfection or air quality?
Contact Natdis today to learn how our UV-C solutions can protect your environment.
