Harmless to Human Far UV-C 222 nm Excimer Lamp 20 Watt for Sterilization and Disinfection

UV-C 222nm sterilization and disinfection also known as UV disinfection or ultraviolet germicidal irradiation (UVGI) works by breaking down certain chemical bonds and scrambling the structure of DNA, RNA and proteins, causing a microorganism to be unable to multiply. Under a certain dose, Far UV-C 222nm can kill most bacteria and viruses within 1 second.

The sterilization and disinfection rate of far UV-C 222nm is related to target microorganism and irradiation dose.

• - To kill general bacterial propagules: the dose should be up to 10000 μW.s/cm²
• - To kill bacterial spores: up to 100000μW.s/cm²
• - To kills viruses: Somewhere between a bacterial propagator and a bud
• - To kill fungal spores: higher than bacterial spores,  sometimes 600000 μW.s/cm²(pathogenic fungi are generally less resistant to ULTRAVIOLET light than bacterial spores)
• - To kill unknown target microorganisms: not less than 100000μW.s/cm²

2. Far UV-C 222nm Photobiological Safety

Penetration of UV wavelengths into human skin: Arrows represent an estimate of 90% absorption depth.UV-C wavelengths at 222nm do not appear to penetrate the stratum corneum; whereas, 254nm does penetrate into upper epidermis. UV-B wavelengths, such as 300nm, do penetrate to the critically important germinative(basal) layer of the epidermis and have sufficient energy to mutate DNA. UV-A wavelengths at 340nm, 360nm, and 400nm penetrate well into the dermis, but the lower photon energies are far less damaging than 300nm.

Penetration of UV wavelengths into human eye. UV-C wavelengths at 222 nm hardly penetrate to the corneal epithelium; whereas, 254nm does penetrate well into the epithelium and into the stroma. There is some evidence of penetration even to the endothelium. UV-B wavelengths, such as 300nm do penetrate to the lens, and oblique rays to the critically important germinative layer of the ledsbahind the iris and have sufficient energy to mutate DNA. UV-A wavelengths are strongly absorbed by fluorophores in the lens and protect the retina.