What is the Nature of UV-Radiation

UV-radiation are electromagnetic waves on the short end of visible light. They are classified as UV"A" (315-380 nm) UV"B" (280-315 nm) and UV"C" (100-280 nm). The sun is the best known natural source of this radiation but artificial sources like high-tech pressure lamps for curing lacquer, printing inks, photocopy equipment, and film exposure methods, and welding arcs are recognized hazards