Ultraviolet (UV) radiation light ka wo hissa hai jo insaani aankhon se dikhayi nahi deta, kyunki iski wavelength visible light se chhoti hoti hai. Is pure spectrum ko teen main categories mein baanta gaya hai:
- UV-A (315–400 nm): Ise “Blacklight” bhi kehte hain. Ye suraj se aane wali 95% UV rays hoti hain jo dharti tak pahunchti hain. Ye skin aging ke liye zimmedar hoti hain.
- UV-B (280–315 nm): Ye rays skin burning aur DNA damage ka kaaran banti hain. Halanki ye khatarnak hain, par ye hamari body mein Vitamin D banane mein madad karti hain.
- UV-C (100–280 nm): Ye sabse zyada powerful aur energy wali rays hain. Shukr hai ki dharti ki Ozone layer ise puri tarah sokh leti hai, warna ye life ke liye khatarnak hoti. Yahi wo spectrum hai jise hum “Germicidal UV” kehte hain.